Resuscitation - Articles in Press

San Antonio Vasopressin in Shock Symposium Report - Corrected Proof

2010-07-26

Abstract: The San Antonio Vasopressin Symposium reviewed substantial accumulated data concerning vasopressin in haemorrhagic, septic, and cardiac arrest shock conditions and found that there is considerable evidence to support the use of vasopressin in overcoming vasopressin deficiency or insufficiency. The value of vasopressin in the setting of trauma requires further investigation. It was concluded that a large, multicenter controlled trial of vasopressin is needed to assess the therapeutic benefit of vasopressin replacement in the setting of trauma with haemorrhagic shock that is prolonged and profound.

Reply to Letter: “Determining core body temperature via heat flux—A new promising approach” - Corrected Proof

Jasper Klewer, Fritz Sterz, Andrea Zeiner — 2010-07-26

The writer of the letter is correct to say that we have not published data showing the performance of the sensor under these circumstances. Our assertion of the difference in performance is based on the theoretical model that both Kimberger and Zeiner et al. are using. This model is expressed in formula 3 in Zeiner's paper and in the formula in Kimberger's paper, which relates the measured heat flux to core temperature by means of the thermal tissue property Kg. In Kimberger's method, this parameter is assumed to be constant at 45Wm−2K−1, ruling out any differences between and within subjects. In contrast, Zeiner's method exploits the zero heat flux principle, making the thermal tissue property irrelevant. The model therefore predicts a robustness against inter-and intrasubject differences in Zeiner's method. Furthermore, Gunga et al. present an extended model to discount for ambient temperatures which was not used by Kimberger et al. In any case, only experiments will provide evidence of performance and the results of Gunga and Kimberger are superb. We hope that in the future patients will benefit from non-invasive core thermometry with the high performance comparable to today's invasive thermometers.

Bystander CPR in south east Scotland increases over 16 years - Corrected Proof

2010-07-26

Abstract: Background: Out-of-hospital cardiac arrest (OHCA) remains a leading cause of mortality and serious neurological disability across Europe. Without immediate bystander cardiopulmonary resuscitation (CPR), chances of survival are minimal. Despite community initiatives to increase the number of trained CPR providers, the effectiveness of these measures remains unknown and the proportion of OHCA patients receiving bystander CPR in the United Kingdom yet to be established. We sought to identify the change in the rate of bystander CPR in south east Scotland over a 16-year period.Methods: Retrospective cohort study of all adult non-traumatic OHCA in south east Scotland from 1 January 1992 to 31 December 2007 using the Heartstart Scotland database.Results: 7928 OHCA were included. The proportion of patients receiving bystander CPR increased from 34% in 1992 to 52% in 2007 (p for trend <0.0001). The rate of CPR from bystanders, spouses and from relatives increased significantly over the study period. Patients arresting at home received significantly less bystander CPR than those arresting away from home (39% vs 52%, p<0.0001) regardless of age or sex.Conclusion: There has been a significant increase in bystander CPR in south east Scotland during the 16-year period. Bystander CPR is associated with an increased rate of survival and targeted CPR training for relatives of patients at risk of sudden cardiac death may be beneficial.

Poor recall of “4Hs and 4Ts” by medical staff - Corrected Proof

Nicola Jones, Craig Lammas, Carl Gwinnutt — 2010-07-26

While running in-hospital “mock” cardiac arrests for staff training, we noticed that medical members of the cardiac arrest team were frequently slow to recall the “four Hs” and “four Ts”, potential causes or aggravating factors of a cardiac arrest for which specific treatment must be considered . We therefore undertook a survey of the knowledge of this aspect of resuscitation amongst the doctors who participate as members of the hospital cardiac arrest team.

Primary percutaneous coronary intervention and thrombolysis improve survival in patients with ST-elevation myocardial infarction and pre-hospital resuscitation - Corrected Proof

2010-07-26

Abstract: Background: Patients with ST-elevation myocardial infarction (STEMI) surviving pre-hospital resuscitation represent a selected subgroup of patients with a very high adverse event rate. Only few data on the outcome of primary percutaneous coronary intervention (primary PCI) and thrombolysis in such patients are available.Methods: We analysed the Maximal Individual Therapy of Acute Myocardial Infarction (MITRA) Plus registry. 1529 survivors of pre-hospital resuscitation with STEMI were included. 593 (38.8%) of those patients did not receive early reperfusion therapy, 793 (51.9%) patients received thrombolysis and 143 (9.4%) patients received primary PCI. Hospital mortality in patients receiving primary PCI or thrombolysis was adjusted for confounding factors with a propensity score analysis.Results: Primary PCI as well as thrombolysis in survivors of pre-hospital resuscitation with STEMI were associated with a significant reduction of hospital mortality (OR: 0.29, 95% CI 0.17–0.50; and 0.74, 95% CI 0.54–0.99, respectively), while primary PCI was superior compared to thrombolysis (OR 0.50, 95% CI 0.30–0.84).Conclusion: Reperfusion therapy improves mortality of patients with STEMI surviving pre-hospital resuscitation, while primary PCI seems to be more effective than thrombolysis.

Successful implementation of a family and patient activated rapid response team in an adult level 1 trauma center - Corrected Proof

2010-07-26

Abstract: Background: When cardiac arrests occur in hospitalized patients, delays in treatment are associated with lower survival and poorer outcomes. Patients often show a physiological deterioration hours before cardiac or pulmonary arrest. As a result, many hospitals have implemented a rapid response team (RRT) as part of their involvement in the 100,000 Lives Campaign sponsored by the Institute for Healthcare Improvement.Method: In conjunction with the University Health System Consortium (UHC) Patient- and Family-Centered Care Implementation Collaborative, Shands Jacksonville Medical Center (SJMC) launched a pilot RRT program in October 2006 followed by campus-wide implementation in July 2007. The program was enhanced to allow patient and family activation of the RRT in October 2007.Results: A review of the first 2 years of data indicates that the SJMC RRT received 25 patient or family activated calls. Forty-eight percent of the calls were initiated by a family member and 52% by the actual patient. Reasons for the calls have varied but the most frequent reason identified by the patient or family member was “something just doesn’t feel right” with the patient. Other leading reasons for calls were similar to criteria that are used by staff-initiated calls, such as shortness of breath and pain issues.Conclusion: This is one of the first initiations of a family activated component of the RRT in an adult hospital that has led to improvements in outcomes such as reduction in mortality rates and non-ICU codes, without an overload of false positive calls.

Statistical considerations in assessing the impact of hospital characteristics and cardiac arrest survival - Corrected Proof

2010-07-26

We read with great interests the two recent publications in the Journal on the impacts of receiving hospital characteristics on outcomes of out-of-hospital cardiac arrests (OHCA). While the result from the Resuscitation Outcomes Consortium showed no association between hospital characteristics such as bed number, cases of OHCAs and catheterization capability and outcomes; data from Osaka, Japan, demonstrated a threefold increase in neurologically favorable survival when patients without field ROSC were transported to critical care medical centers (CCMC) certified by the Ministry of Health.

Emergency medicine and organ donation—A core responsibility at a time of need or threat to professional integrity - Corrected Proof

Dominic Bell — 2010-07-23

Transplantation of cadaveric organs is embedded in contemporary medical practice, having progressed over the last 40 years from experiment to relatively routine care. Initial reservations over the concept of brainstem death were subsumed within professional, public and political fascination and support for transplantation, leading to virtually universal adoption of this donation model. As demand for organs increased and the brainstem-dead population fell through public health initiatives and advances in neuro-critical care, new recruitment strategies have been adopted to maximise donor identification and consent rates. Paralleling these initiatives was the return to non-heart-beating donation (NHBD) or donation after cardiac death (DCD), previously abandoned when the brainstem death concept offered organs at maximal viability. NHBD principally targeted critical care patients with significant neurological injury that although falling short of brainstem death, justified withdrawal of support, classed as ‘controlled’ donation. With supply still lagging behind demand, attention has turned to ‘uncontrolled’ donation within the arena of emergency medicine, targeting unsuccessful resuscitation.

Determining core body temperature via heat flux - a new promising approach - Corrected Proof

Oliver Opatz, Alexander Stahn, Andreas Werner, Hanns-Christian Gunga — 2010-07-21

Zeiner et al. recently published an article about a zero heat flux method to measure core body temperature in mild hypothermia. It has been stated that a similar method, used by Kimberger et al., might show more bias induced by ambient temperature, the patient's physiology and interindividual differences. Moreover it was said that the zero heat flow method eliminates all influences such as ambient temperature, skin perfusion, any physiological changes and interindividual differences. This seems to be a very promising approach. However a piece of literature is missing: showing the device's capabilities under these different ambient and physiological conditions. As for the other criticized heat flow device there are measurement data available showing its performance when comparing head with rectal temperature at different ambient temperatures and physiological stress. Considering the anatomically different measurement sites it showed comparable results to the device of Zeiner et al.

Extended series of cardiac compressions during CPR in a swine model of perinatal asphyxia - Corrected Proof

Anne L. Solevåg, Ingrid Dannevig, Myra Wyckoff, Ola D. Saugstad, Britt Nakstad — 2010-07-21

Abstract: Background: The rationale for a compression to ventilation ratio of 3:1 in neonates with primary hypoxic, hypercapnic cardiac arrest is to emphasize the importance of ventilation; however, there are no published studies testing this approach against alternative methods. An extended series of cardiac compressions offers the theoretical advantage of improving coronary perfusion pressures and hence, we aimed to explore the impact of compression cycles of two different durations.Materials and methods: Newborn swine (n=32, age 12–36h, weight 2.0–2.7kg) were progressively asphyxiated until asystole occurred. Animals were randomized to receive compressions:ventilations 3:1 (n=16) or 9:3 (n=16). Return of spontaneous circulation (ROSC) was defined as a heart rate ≥100beatsmin−1.Results: All animals except one in the 9:3 group achieved ROSC. One animal in the 3:1 group suffered bradycardia at baseline, and was excluded, leaving us with 15 animals in each group surviving to completion of protocol. Time to ROSC (median and interquartile range) was 150s (115–180) vs. 148s (116–195) for 3:1 and 9:3, respectively (P=0.74). There were no differences in diastolic blood pressure during compression cycles or in markers of hypoxia and inflammation. The temporal changes in mean arterial blood pressure, heart rate, arterial blood gas parameters, and systemic and regional oxygen saturation were comparable between groups.Conclusion: Neonatal pigs with asphyxia-induced cardiac arrest did not respond to a compression:ventilation ratio of 9:3 better than to 3:1. Future research should address if alternative compression:ventilation ratios offer advantages over the current gold standard of 3:1.

Randomised comparison of percutaneous left ventricular assist device with open-chest cardiac massage and with surgical assist device during ischaemic cardiac arrest - Corrected Proof

2010-07-21

Abstract: Aims: A percutaneous left ventricular assist device can maintain blood flow to vital organs during ventricular fibrillation and may improve outcomes in ischaemic cardiac arrest. We compared haemodynamic and clinical effects of a percutaneous left ventricular assist device with a larger device deployed via endovascular prosthesis and with open-chest cardiac massage during ischaemic cardiac arrest.Methods: Eighteen swine were randomised into three groups. After thoracotomy, coronary ischaemia and ventricular fibrillation was induced. Cardiac output was measured with transit-time flowmetry. Tissue perfusion was measured with microspheres. Defibrillation was performed after 20min.Results: Cardiac output with cardiac massage was 1129mLmin−1 vs. 1169mLmin−1 with the percutaneous- and 570mLmin−1 with the surgical device (P<0.05 surgical vs. others). End-tidal CO2 was 3.3kPa with cardiac massage vs. 3.2kPa with the percutaneous- and 2.3kPa with the surgical device (P<0.05 surgical vs. others). Subepicardial perfusion was 0.33mLmin−1g−1 with cardiac massage vs. 0.62mLmin−1g−1 with both devices (P<0.05 devices vs. massage), cerebral perfusion was comparable between groups (all reported values after 3min cardiac arrest, all P<0.05 vs. baseline, all P=NS for 3min vs. 15min). Return of spontaneous circulation was achieved in 5/6 subjects with cardiac massage vs. 6/6 with the percutaneous- and 4/6 with the surgical device (P=NS).Conclusion: The percutaneous device improved myocardial perfusion, maintained cerebral perfusion and systemic circulation with similar rates of successful defibrillation vs. cardiac massage. Increased delivery was not obtained with the surgical device during cardiac arrest.

Upper airway obstruction due to spontaneous retropharyngeal hemorrhage - Corrected Proof

Siu-On Tsui, Shu-Fang Hu, Li-Chu Fang, Chih-Cheng Lai, Hen-I. Lin — 2010-07-21

A 60-year-old man presented to the emergency department following progressive shortness of breath for several hours. He also had a 3-day history of a painful swelling over the submental area and neck. He was known to have alcoholic liver disease and chronic hepatitis B. He had no pre-existing disease in the region of neck and did not recall any recent trauma or violent neck movement. The physical examination revealed swelling over the neck without tenderness or erythema. Chest auscultation revealed inspiratory stridor. Laboratory results included white blood cell of 11,040μl, hematocrit of 34.5, platelet of 231,000μl, partial thromboplastin time of 44.7s, and prothrombin time of 11.7s. The renal and liver function tests were normal. The arterial blood gas values in ambient air were: pH 7.073, PaCO2 79.7mmHg, PaO2 71mmHg HCO3 23.3mmol/L. He was intubated for acute respiratory failure. Computed tomography of the neck revealed a prevertebral soft tissue mass from the floor of the mouth to the upper mediastinum (). Prevertebral space hematoma and mediastinum hematoma were confirmed during neck exploration and about 120ml of blood clot was evacuated. The post-operation course was smooth and he was discharged uneventfully two months later.

Risen from the dead: A case of the Lazarus phenomenon—With considerations on the termination of treatment following cardiac arrest in a prehospital setting - Corrected Proof

Niels Henrik Krarup, Anne Kaltoft, Poul Lenler-Petersen — 2010-07-21

The “Lazarus phenomenon” or “spontaneous return of circulation” is characterized as a delayed return of spontaneous circulation, occurring after the termination of resuscitation following cardiac arrest.

The efficacy of straddling external chest compression on a moving stretcher - Corrected Proof

Zhan Lei, He Qing, Zhou Yaxiong — 2010-07-20

Abstract: Objective: To evaluate the efficacy of straddling external chest compression performed on moving stretchers.Methods: The study was a prospective, randomized, cross-over study on a manikin performed at a university hospital. Twenty subjects were selected from the 40 graduates using random numbers to participate in the study. Participants were randomized to either performing standard or straddling external chest compression followed by the other technique 7 days later. The compression variables and time to first compression were recorded.Results: Twenty subjects (12 males and 8 females) took part in the study. There were no differences between the standard and straddling external chest compression for the compression rate, effective compression percentage and compression depth. There was no difference between the standard external chest compression and straddling external chest compression for incorrect hand position and incomplete release compression. Time to first compression during straddling external chest compression (10.31±1.65s) was greater than that during standard external chest compression (2.74±0.40s) (P<0.001).Conclusions: The quality of straddling external chest compression performed on a moving stretcher was as effective as standard external chest compression performed on the floor. By performing straddling external chest compression, time for transporting victims to the emergency department to get advanced life support may be shortened.

Analysis of reasons for emergency call delays in Japan in relation to location: High incidence of correctable causes and the impact of delays on patient outcomes - Corrected Proof

2010-07-20

Abstract: Review: The interval between collapse and emergency call influences the prognosis of out-of-hospital cardiac arrest (OHCA). To reduce the interval, it is essential to identify the causes of delay.Methods: Basal data were collected prospectively by fire departments from 3746 OHCAs witnessed or recognised by citizens and in which resuscitation was attempted by emergency medical technicians (EMTs) between 1 April 2003 and 31 March 2008. EMTs identified the reasons for call delay by interview.Results: The delay, defined as an interval exceeding 2min (median value), was less frequent in the urban region, public places and for witnessed OHCAs. Delay was more frequent in care facilities and for elderly patients and OHCAs with longer response times. Multiple logistic regression analysis indicated that urban regions, care facilities and arrest witnesses are independent factors associated with delay. The ratio of correctable causes (human factors) was high at care facilities and at home, compared with other places. Calling others was a major reason for delay in all places. Performing cardiopulmonary resuscitation (CPR) and other treatments was another major reason at care facilities. Large delay, defined as an interval exceeding 5min (upper-quartile value), was an independent factor associated with a low 1-year survival rate.Conclusion: The incidence of correctable causes of delay is high in the community. Correction of emergency call manuals in care facilities and public relation efforts to facilitate an early emergency call may be necessary. Basic life support (BLS) education should be modified to minimise delays related to making an emergency call.

A longstanding error by Ernest Henry Starling - Corrected Proof

Peter Faybik, Daniel Lahner, Wolfgang Schramm — 2010-07-20

We read with great interest the experimental paper of Ayoub et al. on the effect of cariporide given during resuscitation on the promotion of electrical and mechanical cardiac activity. Beside other effects, they found cariporide to significantly attenuate the decrease of the left ventricular stroke work index (LVSWI) after resuscitation. However, instead of the unit Joule·m−2, they have chosen an incorrect unit for the LVSWI, namely gm-m/beat/m2. Correct units are imperative when comparing scientific papers and only units of energy are correct for LVSWI. According to a recent literature research, Ayoub et al. are not the first authors, who made this significant error. At least 23 scientific publications have chosen this incorrect unit for the left ventricular stroke work within the last 56 years. Tracing back the unit gram·meter (g·m), one finds that none other than Starling himself invented this fictitious unit, kilogram·meter per hour, 83 years ago for measuring power (i.e. energy per time) of the heart. Even though the fictitious unit gm-m/beat/m2 in Ayoub's paper does not change their conclusions, isn’t it time that we use the correct units, especially SI-system units, in medicine?

A randomised trial comparing a 4-stage to 2-stage teaching technique for laryngeal mask insertion - Corrected Proof

S. Orde, A. Celenza, M. Pinder — 2010-07-20

Abstract: Objective: To compare the ‘4-stage’ teaching technique (demonstration, deconstruction, formulation, performance) with the traditional ‘2-stage’ teaching technique (deconstruction, performance) in laryngeal mask airway (LMA) insertion.Methods: Using a prospective randomised study design, participants were taught LMA insertion on a manikin by either the ‘2-stage’ or ‘4-stage’ teaching method. Subjects were eligible if they had never inserted a LMA. Skill acquisition was assessed immediately following training, and skill retention assessed a number of weeks later. The primary outcome was LMA insertion on a manikin, with successful ventilation within 30s. Other outcomes included overall time to LMA insertion, and number of errors. Assessors were blinded to the teaching method used for each subject.Results: A total of 120 participants were randomised between the two teaching groups (60 subjects in each group). Mean time to LMA insertion at acquisition was 39.7s for 2-stage and 34.7s for 4-stage (p>0.05), and proportion completing within 30s was 41.67% for 2-stage and 48.33% for the 4-stage teaching group (p>0.05). With skill retention assessment, mean time to LMA insertion was 44.3s for 2-stage and 42.5s for the 4-stage teaching group (p>0.05). Proportion completing task within 30s was 34.0% for 2-stage and 41.67% for 4-stage group (p>0.05). Overall, there was no significant difference found in skill acquisition or in skill retention between the 2 or 4-stage teaching method.Conclusion: The 2-stage teaching technique is not statistically different to the 4-stage teaching method in efficacy of LMA insertion skill acquisition or retention.

Comparison of tracheal intubation using the Macintosh laryngoscope, AirWay Scope and gum elastic bougie under chest compression and cervical stabilisation - Corrected Proof

F.S. Xue, J. Xiong, Q. Wang, Y.J. Yuan, X. Liao — 2010-07-20

The recent article of Maruyama et al. comparing the tracheal intubation using the Macintosh laryngoscope, AirWay Scope (AWS), and gum elastic bougie under chest compression and cervical stabilisation a manikin study was of great interest to us. Although they have provided vast valuable information, we would urge caution in the interpretation of results and their extrapolation to any clinical setting.

How many emergency dispatches occurred per cardiac arrest? - Corrected Proof

Nicholas J. Johnson, Karl A. Sporer — 2010-07-20

Abstract: Background: The Medical Priority Dispatch System (MPDS) is an emergency medical dispatch (EMD) system that is widely used to prioritize 9-1-1 calls and optimize resource allocation. Calls are assigned an MPDS determinant, which includes a number (1–32) representing chief complaint and priority (Alpha through Echo) representing acuity.Objective: This study evaluates the number of emergency dispatches per cardiac arrest (NOD-CA) in cardiac arrest and non-cardiac arrest MPDS determinants.Methods: All patients assigned a determinant by MPDS from January 1, 2008 to June 30, 2009 in a large metropolitan area were included. Prehospital electronic patient care records were linked with dispatch data. For each MPDS determinant, the number of calls for which the paramedic impression was listed as “Cardiac Arrest – Non-Traumatic” was tabulated. The NOD-CA was calculated for each cardiac arrest and non-cardiac arrest MPDS determinant. Non-MPDS calls with cardiac arrests were analyzed separately.Results: A total of 101,642 patients were included. Among them, 555 had “Cardiac Arrest – Non-Traumatic” listed as the paramedic impression. The Cardiac/Respiratory Arrest/Death protocol had the highest number of cardiac arrests (285), followed by Breathing Problems (99) and Unconscious/Fainting (76). Overall, 183 dispatched occurred for each cardiac arrest, 131 of which resulted in a lights and sirens response. The NOD-CA was 7 in the Cardiac Arrest/Death protocol, 122 in Breathing Problems, and 104 in Unconscious/Fainting. 31 Cardiac arrests occurred in non-MPDS dispatch categories (N=62,989), most of which were calls for medical assistance from police or fire units.Conclusions: MPDS was designed to detect cardiac arrest with high sensitivity, leading to a significant degree of mistriage. The number of dispatches for each cardiac arrest may be a useful way to quantify the degree of mistriage and optimize EMS dispatch. This large descriptive study revealed a low NOD-CA in most cardiac arrest MPDS determinants. We demonstrated significant variability in the NOD-CA among non-cardiac arrest MPDS determinants, and few cardiac arrests in non-MPDS dispatch categories.

Testing the validity of the ATLS classification of hypovolaemic shock - Corrected Proof

H.R. Guly, O. Bouamra, R. Little, P. Dark, T. Coats, P. Driscoll, F.E. Lecky — 2010-07-12

Abstract: Aim: The Advanced Trauma Life Support system classifies the severity of shock. The aim of this study is to test the validity of this classification.Methods: Admission physiology, injury and outcome variables from adult injured patients presenting to hospitals in England and Wales between 1989 and 2007 and stored on the Trauma Audit and Research Network (TARN) database, were studied. Patients were divided into groups representing the four ATLS classes of shock, based on heart rate (HR) systolic blood pressure (SBP), respiratory rate (RR) and Glasgow Coma Score (GCS). The relationships between variables were examined by classifying the cohort by each recorded variable in turn and deriving the median and interquartile range (IQR) of the remaining three variables. Patients with penetrating trauma and major injuries were examined in sub-group analyses.Results: In blunt trauma patients grouped by HR, the median SBP decreased from 128mmHg in patients with HR<100BPM to 114mmHg in those with HR>140BPM. The median RR increased from 18 to 22bpm and the GCS reduced from 15 to 14. The median HR in hypotensive patients was 88BPM compared to 83BPM in normotensive patients and the RR was the same. When grouped by RR, the HR increased with increasing RR but there were no changes in SBP.Conclusion: In trauma patients there is an inter-relationship between derangements of HR, SBP, RR and GCS but not to the same degree as that suggested by the ATLS classification of shock.

Management of traumatic occult pneumothorax - Corrected Proof

Kabir Yadav, Mohammad Jalili, Shahriar Zehtabchi — 2010-07-12

Abstract: Study objective: Occult pneumothorax (OPTX) is defined as a pneumothorax seen on computed tomography but not apparent on supine plain radiography. Though increasingly common, the acute management of OPTX after trauma remains controversial. This evidence-based review evaluates the existing evidence regarding the safety and efficacy of observation as compared to tube thoracostomy (TT) for management of OPTX in emergency department trauma patients.Methods: The authors searched MEDLINE, EMBASE, the Cochrane Library, and other databases. Inclusion criteria: studies of adult or pediatric trauma victims at first presentation after blunt or penetrating injury (population), randomized to observation (intervention) or TT (comparison). Studies that enrolled patients on positive pressure ventilation were included but those that enrolled hemodynamically unstable patients were excluded. Outcomes of interest included progression of OPTX, mortality, complications (pneumonia, empyema), and length of stay in hospital and intensive care unit (ICU).Results: A total of 411 articles were identified. After applying the inclusion/exclusion criteria, 3 randomized trials enrolling a total of 101 patients were found to have acceptable quality standards suitable for analysis. The included studies did not reveal any significant difference between observation and TT in regards to progression of OPTX, risk of pneumonia, or length of stay in hospital or ICU. Mortality risk and empyema rate were also not different in the single studies that reported those outcomes.Conclusion: The existing evidence leads to the conclusion that observation is at least as safe and effective as tube thoracostomy for management of occult pneumothorax.

Mid-arm circumference can be used to estimate children's weights - Corrected Proof

G.N. Cattermole, P.Y.M. Leung, P.S.K. Mak, C.A. Graham, T.H. Rainer — 2010-07-12

Abstract: Introduction: Accurate measurement of children's weight is rarely possible in paediatric resuscitation, and rapid estimates are made to ensure appropriate drug and fluid doses and equipment selection. Weight is commonly estimated from formulae based on children's age, or from their height using the Broselow tape. Foot-length and mid-arm circumference have also been suggested as the basis of weight-estimation formulae.Objectives: To determine which of age, height, foot-length or mid-arm circumference had the strongest relationship with weight in healthy children, to derive a simple weight-estimation formula from the strongest correlate, and to compare its performance with existing weight-estimation tools.Methods: This was a population-based prospective observational study of Hong Kong Chinese children aged 1–11 years old last birthday. Weight was measured to the nearest 0.2kg; height, foot-length and mid-arm circumference to the nearest 0.1cm. Multiple regression analysis was used to determine the strongest independent relationships with weight, and linear regression analysis derived a weight-estimation formula. Accuracy and precision of this formula were compared with standard age-based and height-based weight-estimation methods.Results: Mid-arm circumference had the strongest relationship with weight, and this relationship grew stronger with age. The formula, weight [kg]=(mid-arm circumference [cm]−10)×3, was at least as accurate and precise as the Broselow method and outperformed the age-based rule in school-age children, but was inadequate in pre-school children.Conclusion: This weight-estimation formula based on mid-arm circumference is reliable for use in school-age children, and an arm-tape could be considered as an alternative to the Broselow tape in this population.

The Easytube for airway management in prehospital emergency medicine - Corrected Proof

2010-07-12

Abstract: Background: Securing the airway in emergency is among the key requirements of appropriate prehospital therapy. The Easytube (Ezt) is a relatively new device, which combines the advantages of both an infraglottic and supraglottic airway.Aims: Our goal was to evaluate the effectiveness and the safety of use of Ezt by emergency physicians in case of difficult airway management in a prehospital setting with minimal training.Methods: We performed a prospective multi-centre observational study of patients requiring airway management conducted in prehospital emergency medicine in France by 3 French mobile intensive care units from October 2007 to October 2008.Results: Data were available for 239 patients who needed airway management. Two groups were individualized: the “easy airway management” group (225 patients; 94%) and the “difficult airway management” group (14 patients; 6%). All patients had a successful airway management. The Ezt was used in eight men and six women; mean age was 64 years. It was used for ventilation for a maximum of 150min and the mean time was 65min. It was positioned successfully at first attempt, except for two patients, one needed an adjustment because of an air leak, and in the other patient the Ezt was replaced due to complete obstruction of the Ezt during bronchial suction.Conclusion: The present study shows that emergency physicians in cases of difficult airway management can use the EzT safely and effectively with minimal training. Because of its very high success rate in ventilation, the possibility of blind intubation, the low failure rate after a short training period. It could be introduced in new guidelines to manage difficult airway in prehospital emergency.

Impaired recovery of cardiac output and mean arterial pressure after successful defibrillation in patients with low left ventricular ejection fraction - Corrected Proof

2010-07-08

Abstract: Background: Early defibrillation clearly improves survival from malignant arrhythmia. However, in some cases the cause of death will only be altered from arrhythmic to nonarrhythmic. We evaluated the impact of left ventricular ejection fraction (LVEF) on trend and recovery profile of beat-to-beat cardiac output (CO) and mean arterial blood pressure (MAP) after successful defibrillation.Methods: We investigated 63 NYHA class I-III patients undergoing threshold testing in the course of insertion of an implantable cardioverter defibrillator (ICD) in monitored anaesthesia care. Preoperatively, LVEF was classified as either normal (>50%), moderately (30–50%) or severely impaired (<30%). CO and MAP were measured continuously throughout the implantation procedure.Results: Arrest time and body mass index were not different between groups. CO in patients with severely and moderately reduced LVEF dropped 21% and 13% below baseline (P<0.05), respectively. MAP also decreased by 26% and 17%, respectively. In contrast, 45% of patients with LVEF>50% showed sympathetic activation that resulted in a 12% and 2% increase in mean values for CO and MAP, respectively. In relation to patients with LVEF<50%, CO and MAP values were significantly higher after defibrillation (P<0.05). Additionally, recovery of CO was prolonged in the groups with ventricular dysfunction (P<0.05). Temporary post-shock pacing was observed in 40% of patients.Conclusions: A large number of ICD patients with restricted LVEF appears to lack the ability to quickly restore CO and MAP after successful defibrillation. Organ reperfusion may thus still be compromised.

Neurologic prognostication and bispectral index monitoring after resuscitation from cardiac arrest - Corrected Proof

2010-07-05

Abstract: Objective: While the use of therapeutic hypothermia (TH) has improved outcomes after resuscitation from cardiac arrest, prognostication of survival and neurologic function remains difficult during the post-arrest time period. Bispectral index (BIS) monitoring, a non-invasive measurement of simplified electroencephalographic data, is increasingly being considered for post-arrest neurologic assessment and outcomes prediction, although data supporting the technique are limited. We hypothesized that BIS values within 24h after resuscitation would correlate with neurologic outcomes at discharge.Methods: We prospectively collected BIS data in consecutive patients initially resuscitated from cardiac arrest and treated with TH in one academic medical center. We assessed BIS values in context of cerebral performance category (CPC) assessment on the day of discharge.Results: Data were collected in 62 post-arrest patients, of whom 26/62 (42%) survived to hospital discharge. Mean BIS values at 24h post-resuscitation were significantly different in the survivors with CPC 1–2 (“good” outcome) vs those with CPC 3–5 (“poor” outcome) or death during hospitalization (49±13 vs 30±20; p<0.001). Receiver operator characteristic analysis suggested that 24h BIS was most predictive of CPC 1–2 outcome compared to the other timepoints; a BIS cutpoint of 45 exhibited a sensitivity of 63% and a specificity of 86%, with a positive likelihood ratio of 4.67. Sixteen patients exhibited a BIS of zero during at least one timepoint; all of these patients died during hospitalization.Conclusions: BIS monitoring values at 24h post-resuscitation are correlated with neurologic outcomes in patients undergoing TH treatment. In 16/62 patients, a BIS of zero at any timepoint was observed, which was uniformly correlated with poor outcome after resuscitation from cardiac arrest; however, a non-zero BIS is insufficient as a sole predictor of good neurologic survival.

Therapeutic hypothermia after cardiac arrest: A retrospective comparison of surface and endovascular cooling techniques - Corrected Proof

2010-07-05

Abstract: Objectives: Therapeutic hypothermia (32–34°C) is recommended for comatose survivors of cardiac arrest; however, the optimal technique for cooling is unknown. We aimed to compare therapeutic hypothermia using either surface or endovascular techniques in terms of efficacy, complications and outcome.Design: Retrospective cohort study.Setting: Thirty-bed teaching hospital intensive care unit (ICU).Patients: All patients (n=83) undergoing therapeutic hypothermia following cardiac arrest over a 2.5-year period. The mean age was 61±16 years; 88% of arrests occurred out of hospital, and 64% were ventricular fibrillation/tachycardia.Interventions: Therapeutic hypothermia was initiated in the ICU using iced Hartmann's solution, followed by either surface (n=41) or endovascular (n=42) cooling; choice of technique was based upon endovascular device availability. The target temperature was 32–34°C for 12–24h, followed by rewarming at a rate of 0.25°Ch−1.Measurements and main results: Endovascular cooling provided a longer time within the target temperature range (p=0.02), less temperature fluctuation (p=0.003), better control during rewarming (0.04), and a lower 48-h temperature load (p=0.008). Endovascular cooling also produced less cooling-associated complications in terms of both overcooling (p=0.05) and failure to reach the target temperature (p=0.04). After adjustment for known confounders, there were no differences in outcome between the groups in terms of ICU or hospital mortality, ventilator free days and neurological outcome.Conclusion: Endovascular cooling provides better temperature management than surface cooling, as well as a more favorable complication profile. The equivalence in outcome suggested by this small study requires confirmation in a randomized trial.

Educational impact of a hospital-based neonatal resuscitation program in Ghana - Corrected Proof

2010-07-05

Abstract: Aim of the study: To assess midwives’ baseline cognitive knowledge of evidence-based neonatal resuscitation practices, and short- and long-term educational effects of teaching a neonatal resuscitation program in a hospital setting in West Africa.Methods: All midwives (n=14) on the labor ward at Ridge Hospital in Ghana were trained using materials modified from the American Academy of Pediatrics (AAP) Neonatal Resuscitation Program (NRP). This training program included didactic and practical teaching and was assessed by direct observation within delivery rooms and written pre- and post-test evaluations. Written and practical modules 9–12 months after the initial training session were also conducted to assess retention of NRP knowledge and skills.Results: Fourteen midwives received NRP training on the labor ward. Both written and practical evaluation of neonatal resuscitation skills increased after training. The percentage of items answered correctly on the written examination increased from 56% pre-training to 71% post-training (p<0.01). The percentage of items performed correctly on the practical evaluation of skills increased from 58% pre-training to 81% (p<0.01). These results were sustained 9–12 months after the initial training session.Conclusion: After receiving NRP training, neonatal resuscitation knowledge and skills increased among midwives in a hospital in West Africa and were sustained over a 9-month period. This finding demonstrates the sustained effectiveness of a modified neonatal resuscitation training program in a resource constrained setting.

Re: Letter to Resuscitation, Carretero et al. - Corrected Proof

Henry Halperin, Norman Paradis — 2010-07-05

Carretaro et al. should be commended for evaluating a potentially new technology for measuring cardiac output noninvasively in the low-flow state of cardiac arrest. As they point out, thermodilution is generally not applicable in this setting, and end-tidal CO2 is an indirect indicator. Their data would seem to demonstrate that noninvasive partial CO2 reading breathing may be a useful biomarker of hemodynamics in this setting, if validated by other investigators.

Model of cardiac arrest in rats by transcutaneous electrical epicardium stimulation - Corrected Proof

2010-07-05

Abstract: Objective: To establish a new model of cardiac arrest (CA) in rats by transcutaneous electrical epicardium stimulation.Methods: Two acupuncture needles connected to the anode and cathode of a stimulator were transcutaneously inserted into the epicardium as electrodes. The stimulating current was steered to the epicardium and the stimulation was maintained for 3min to induce CA. Cardiopulmonary resuscitation (CPR) was performed at 6min after a period of nonintervention.Results: CA was successfully induced in a total of 20 rats. The success rate of induction was 12/20 at the current intensity of 1mA; and reached 20/20 when the current intensity was increased to 2mA. After the electrical stimulation, the femoral blood pressure quickly dropped below 25mmHg and the arterial pulse waveform disappeared. The average time from the electrical stimulation to CA induction was 5.10 (±2.81)s. When the electrical stimulation stopped, 18/20 rats had ventricular fibrillation and 2/20 rats had pulseless electrical activity. CPR was performed for averagely 207.4 (±148.8)s. The restoration of spontaneous circulation (ROSC) was 20/20. The death rate within 4h after ROSC was 5/20, and the 72-h survival rate was 10/20. There were only two cases of complications, a minor muscle contraction and a minor lung lobe injury.Conclusion: The model of CA in rats induced by transcutaneous electrical epicardium stimulation is a stable model that requires low-intensity current and has fewer complications. This model may provide another option for experimental research of CA induced by malignant arrhythmia (especially VF).

Comparison of three types of laryngoscope for tracheal intubation during rhythmic chest compressions: A manikin study - Corrected Proof

J. Koyama, T. Iwashita, K. Okamoto — 2010-07-05

Abstract: Background: If tracheal intubation can be performed during uninterrupted chest compressions, this will sustain circulation during the procedure of intubation and may lead to successful resuscitation. We compared three types of laryngoscope on a manikin as to whether they enabled tracheal intubation while the manikin's chest was rhythmically compressed.Methods: A total of 35 persons who had little or no experience in intubation served as examinees. The laryngoscopes employed were a conventional Macintosh laryngoscope (MAC), a new video laryngoscope, Pentax-AWS (AWS) and an optic laryngoscope Airtraq (ATQ). During chest compression on the manikin by an assistant, the examinee attempted to perform intubation. The success rate and the time for successful intubation were measured.Results: During rhythmic chest compressions, nine examinees failed in tracheal intubation with the MAC, seven failed with the ATQ, and no one failed with the AWS. The success rates with the AWS were significantly higher than those with the MAC (P<0.01) or ATQ (P<0.05). The time needed for intubation was significantly shorter with the Pentax-AWS than with the others.Conclusions: These results suggest that the use of the Pentax-AWS enables tracheal intubation while the patient's chest is rhythmically compressed, and would more often lead to successful intubation, which in turn may lead to more successful resuscitation.

Rapid sequence airway using the LMA-Supreme as a primary airway for 9h in a multi-system trauma patient - Corrected Proof

Darren Braude, Andrew Southard, Timothy Bajema, Ethan Sims, John Martinez — 2010-07-05

A 22-year-old male was involved in a single vehicle collision in a remote area. Paramedics found the patient to have a GCS of 3, massive facial deformities, blood gurgling from the mouth, and an oxygen saturation of 30%. The crew elected to perform Rapid Sequence Airway (RSA) while simultaneously preparing for a surgical airway. After etomidate and rocuronium a #4 LMA-Supreme™ (LMAS) with 14Fr gastric tube was placed on the first attempt and the stomach decompressed. Oxygen saturation increased steadily to 90%.

Acquisition and retention of basic life support skills in an untrained population using a personal resuscitation manikin and video self-instruction (VSI) - Corrected Proof

2010-07-05

Abstract: Background: Video-based self-instruction (VSI) with a 24-min DVD and a personal resuscitation manikin solves some of the barriers associated with traditional basic life support (BLS) courses. No accurate assessment of the actual improvement in skills after attending a VSI course has been determined, and in this study we assess the skill improvement in laypersons undergoing VSI.Methods: The BLS skills of 68 untrained laypersons (high school students, their teachers and persons excluded from mainstream society) were assessed using the Laerdal ResusciAnne and PC Skill Reporting System 2.0 in a 3min test. A total score (12–48 points) was calculated and 12 different variables were recorded. The participants attended a 24-min VSI course (MiniAnne, Laerdal) and took home the DVD and manikin for optional subsequent self-training. We repeated the test 3½–4 months later.Results: There was a significant increase in the total score (p<0.0001) from 26.5 to 34 points. The participants performed significantly better in checking responsiveness, opening the airway, checking for respiration and using the correct compression/ventilation ratio (all p-values<0.001). The compression depth improved from 38mm to 49.5mm and the total number of compressions increased from 67 to 141. The ventilation volume and the total number of ventilations increased, and total “hands-off” time decreased from 120.5s to 85s.Conclusions: Untrained laypersons attending a 24min DVD-based BLS course have a significantly improved BLS performance after 3½–4 months compared to pre-test skill performance. Especially the total number of compressions improved and the hands-off time decreased.

In-hospital cardiac arrest: Is it time for an in-hospital ‘chain of prevention’? - Corrected Proof

Gary B. Smith — 2010-07-02

Abstract: The ‘chain of survival’ has been a useful tool for improving the understanding of, and the quality of the response to, cardiac arrest for many years. In the 2005 European Resuscitation Council Guidelines the importance of recognising critical illness and preventing cardiac arrest was highlighted by their inclusion as the first link in a new four-ring ‘chain of survival’. However, recognising critical illness and preventing cardiac arrest are complex tasks, each requiring the presence of several essential steps to ensure clinical success. This article proposes the adoption of an additional chain for in-hospital settings – a ‘chain of prevention’ – to assist hospitals in structuring their care processes to prevent and detect patient deterioration and cardiac arrest. The five rings of the chain represent ‘staff education’, ‘monitoring’, ‘recognition’, the ‘call for help’ and the ‘response’. It is believed that a ‘chain of prevention’ has the potential to be understood well by hospital clinical staff of all grades, disciplines and specialties, patients, and their families and friends. The chain provides a structure for research to identify the importance of each of the various components of rapid response systems.

Interpretation and intent: A study of the (mis)understanding of DNAR orders in a teaching hospital - Corrected Proof

Zoë Fritz, Jonathan Fuld, Stephen Haydock, Chris Palmer — 2010-07-02

Abstract: Do not attempt resuscitation (DNAR) orders have been shown to be subject to misinterpretation in the 1980s and 1990s. We investigated whether this was still the case, and examined what perceptions doctors and nurses had of what care patients with DNAR orders receive.Methods: Using an anonymous written questionnaire, we directly approached 50 doctors and 40 nurses from a range of medical specialities and grades in our teaching hospital.Results: All 50 physicians and 35/40 nurses took part. Using McNemar's test, there were highly significant differences (p<0.0001) in what doctors believed ‘should’ take place and what they perceived ‘in practice’ occurred on patients with DNAR orders in all areas questioned (e.g., frequency of nursing observations and contacting medical staff in the event of a patient's deterioration). Using Fisher's exact test, there were significant differences between what nursing staff thought occurred and what doctors thought should occur, for example, frequency of nursing observations (p<0.001), contacting the medical team (p=0.01) and giving fluids (p<0.005).Conclusions: Despite widespread use of DNAR orders, they are still misunderstood. This article highlights the frequency with which DNAR orders are interpreted to mean that other care should be withheld. In addition, it shows that although some doctors know that this should not be the case, they believe that DNAR orders affect the care that their patients receive. We propose that options for more detailed care plans should be embedded within the resuscitation decision and documentation to improve communication and understanding.

Relationship between injury severity and serum tau protein levels in traumatic brain injured rats - Corrected Proof

2010-07-02

Abstract: Background: Although serum tau protein levels increase following TBI, the time course is unknown. The aim of the present study was to determine whether serum tau protein levels increased in both a severity-dependent and time-dependent manner in an experimental model of rat traumatic brain injury (TBI).Methods: A total of 24 Sprague-Dawley rats were subjected to varying grades of TBI using a contusion injury model on the right parietal cortex. Enzyme-linked Immunoabsorbent Assay (ELISA) analysis for serum was performed at 15min pre-injury, 1, 6, 24, 48, and 168h post-injury. Immunoblotting for serum tau protein, neurological evaluation and histological observation were also performed.Results: Tau protein levels rapidly increased after 1h in both mild and severe TBI groups (p<0.001), and declined after 6h. In the sham-operated group, tau protein levels did not change significantly after TBI. Tau protein levels were severity-dependent at 1 and 6h after TBI. The levels were higher in the severe TBI group than in the mild TBI group at 1h (p<0.001) and 6h (p<0.001).Conclusions: Serum tau protein levels were severity-dependent and time-dependent at 1 and 6h after TBI. However, the serum tau protein may not be a useful marker 24h after TBI.

Effects of cerebral hypoperfusion on bispectral index: A randomised, controlled animal experiment during haemorrhagic shock - Corrected Proof

2010-07-02

Abstract: Background: The aim of this porcine haemorrhagic shock model was to investigate the changes of bispectral index (BIS) after slow and fast recovery of cerebral perfusion, and its correlation with plasma propofol concentrations.Methods: After Animal Investigational Committee approval, 16 pigs during propofol anaesthesia underwent a liver trauma with severe hypotension, and were randomly assigned to receive therapy for either slow recovery (fluid resuscitation; slow group; n=8) or fast recovery of cerebral perfusion (vasopressor combined with hypertonic-saline-starch; fast group; n=8), respectively. Cerebral perfusion pressure (CPP=MAP−ICP), cerebral tissue oxygenation index (TOI), BIS, and plasma concentrations of propofol and haemoglobin were measured at baseline (Pre-shock), haemodynamic decompensation (Shock), and 5 (Therapy) and 30min (End) after therapy, respectively.Results: CPP, TOI, and BIS decreased significantly during shock (pre-shock vs. shock, fast: CPP: 65±14 vs. 15±4mmHg; TOI: 64±6 vs. 47±7%; BIS 60±5 vs. 9±10; slow: CPP: 60±12 vs. 13±7mmHg; TOI: 68±7 vs. 49±7%; BIS 63±5 vs. 13±12; P<0.05). In the fast group, CPP, TOI, and BIS increased after therapy compared to the slow group (Therapy, fast: CPP: 47±15mmHg, TOI: 61±7%, BIS: 47±21; slow: CPP: 18±9mmHg, TOI: 51±5%, BIS: 21±19; P<0.05). Propofol and haemoglobin concentrations were comparable between groups throughout the resuscitation phase.Conclusions: In a haemorrhagic shock scenario, therapies with different impact on cerebral perfusion resulted in differing changes of BIS values, while plasma propofol and haemoglobin concentrations were comparable during the resuscitation phase; this suggests that BIS may also have reflected changes of cerebral perfusion.

Reply letter to: Continuous chest compression resuscitation in arrested swine with upper airway inspiratory obstruction: Conclusion supported by data? - Corrected Proof

Gordon A. Ewy, Karl B. Kern — 2010-06-24

We appreciate the letter by Kenneth Gundersen and agree that based on the small number of swine in each subgroup studied in our experimental paper entitled “Continuous chest compression resuscitation in arrested swine with upper airway inspiratory obstruction” that one cannot (and we did not) conclude that Continuous Chest Compression (CCC) is the preferred method for basic life support of subjects with primary cardiac arrest. This study, as we noted under the sub-section “limitations”, has the potential for a significant beta error.

Fresh-frozen plasma transfusion strategy in trauma with massive and ongoing bleeding. Common (sense) and sensibility - Corrected Proof

2010-06-23

Abstract: During trauma resuscitation involving massive transfusion, the best fresh-frozen plasma to packed red blood cells ratio is unknown. No randomised controlled trial (RCT) is available on this subject, although there are plenty of observational studies suggesting that the ratio should be about 1:1. This ratio also makes more physiological sense, and we suggest that in patients with massive and ongoing bleeding, it is a sensible strategy with which to start resuscitation.

Systematic development of web based CPR instruction in the emerging global smart phone era - Corrected Proof

Je Sung You, Jong Woo Park, Sung Pil Chung, Saehwan Park — 2010-06-21

We have read the article by Saraç and Ok with great interest. We completely agree with their conclusion and would like to add our opinion about the study. Recently smart phones such as the iPhone and Blackberry have brought significant change to communication methods and the acquisition of information. Rapid spread of these devices has been associated with new trends of communication in the Republic of South Korea. The public can use existing audio communication as well as the 3G cellular phone with video-telephony and wireless web access on a real time basis. Currently, the acquisition of new information and knowledge with smart phones has become easy and rapid. However, several studies such as the study reported by Saraç and Ok showed that web-based instruction of cardiopulmonary resuscitation (CPR) had a relatively lower effectiveness with regard to performance quality, compared to more traditional training techniques. In particular, CPR instructional methods based on video-clips or web programs showed poor performance quality for the chest compression depth and rate compared to the traditional instructional methods. However, online training for the acquisition of knowledge for CPR can be an effective instruction modality.

Association between clinical examination and outcome after cardiac arrest - Corrected Proof

2010-06-21

Abstract: Background: Neurologic prognostication after cardiac arrest relies on clinical examination findings derived before the advent of therapeutic hypothermia (TH). We measured the association between clinical examination findings at hospital arrival, 24, and 72h after cardiac arrest in a modern intensive care unit setting.Methods: Between 1/1/2005 and 3/31/2009, hospital charts were reviewed in 272 subjects for neurologic examination findings (Glasgow Coma Score – motor examination, pupil response, corneal response) at hospital arrival, 24, and 72h following cardiac arrest. Primary outcome was survival to hospital discharge. Secondary outcome was “good outcome,” defined as discharge to home or acute rehabilitation facility.Results: Mean age was 61 years; 155 (57%) were male. Most were treated with TH (N=161; 59%) and 100 subjects (37%) were in ventricular fibrillation/ventricular tachycardia. Out-of-hospital cardiac arrest was common (N=169; 62%). Ninety-one (33%) survived, with 54 (20%) experiencing a good outcome.In subjects with a GCS Motor score ≤3 at 24 and 72h survival was 17% (13/76; 95% CI 7.9–26.2%) and 20% (6/27; 95% CI 6.3–33.6%), respectively. Subjects with a GCS Motor score ≤2 at 24 and 72h survived in 14% (9/66; 95% CI 4.6–22.6%) and 18% (6/33; 95% CI 3.5–32.8%), respectively. Absent pupil reactivity on arrival did not exclude survival (7/65; 11%; 95% CI 2.4–19%). A lack of pupil reactivity or corneal response at 72h was associated with death (pupil: 0/17; 95% CI 0, 2.9%; corneal: 0/21; 95% CI 0, 2.4%).Conclusions: GCS Motor score ≤3 or ≤2 at 24 or 72h following cardiac arrest does not exclude survival or good outcome. However, absent pupil or corneal response at 72h appears to exclude survival and good outcome.

Continuous chest compression resuscitation in arrested swine with upper airway inspiratory obstruction: Conclusion supported by data? - Corrected Proof

Kenneth Gundersen — 2010-06-21

We read with interest the study of Ewy et al., comparing “24-h survival rates and neurological function of swine in cardiac arrest treated with one of three forms of simulated basic life support CPR”. The investigators found no difference in neurological outcome between constant chest compressions (CCC) with and without obstructed airways and standard 30:2 basic life support (BLS). They conclude that their “findings support the recommendation that following the activation of emergency medical services, continuous chest compressions should be recommended for all bystanders who witness unexpected cardiac arrest.” As the authors point out, a limitation of the study is that with the high number of survivors (28) and the low number of animals (30) the possibility of a ‘beta error’ (false-negative) cannot be ruled out. In our view a (pre-hock) statistical power analysis should have been performed to justify that the study was powered to detect a relevant, pre-defined difference in outcome between the three groups. As it is, without this power analysis one has little or no indication to what level of support these data give for (1) the hypothesis that airway obstruction during CCC has no impact on 24-h post-resuscitation neurological outcome, or (2) the hypothesis that outcome with CCC, with or without obstructed airways, is as good or better than with standard 30:2 BLS. Therefore we deem that it is unknown whether the above-mentioned recommendation is supported by the data presented in this study.

Biphasic DC shock cardioverting doses for paediatric atrial dysrhythmias - Corrected Proof

2010-06-18

Abstract: Objective: To determine cardioversion doses of biphasic DC shock for paediatric atrial dysrhythmias.Design: Prospective recording of energy, pre-shock and post-shock rhythms.Setting: Paediatric hospital.Patients: Shockable atrial dysrhythmias.Main results: Forty episodes of atrial dysrhythmias among 25 children (mean age 6.8±7.1 years, mean weight 28.2±28.5kg) were treated with external shock. The first shock converted the dysrhythmia to sinus rhythm in 25 episodes. Cardioversion occurred in 2 of 8 (25%) episodes with a dose of <0.5J/kg, 14 of 16 (88%) with a dose of 0.5–1.0J/kg and 9 of 16 (56%) with a dose of >1.0J/kg (p=0.01, Fisher's exact test). Ten of 15 initially non-responsive episodes were cardioverted with additional shocks at 1.1±0.6J/kg (range 0.5–2.1J/kg). Of the remaining 5 unresponsive episodes, 2 of ventricular fibrillation (induced by unsynchronized shock) were successfully defibrillated, and 3 were managed with cardiopulmonary bypass. Among 11 additional children (mean age 4.3±6.8 years, mean weight 18.1±22.0kg), 18 episodes of atrial dysrhythmias were treated with internal shock which successfully cardioverted all episodes with one or more shocks at 0.4±0.2J/kg.Conclusions: In rounded doses, recommended initial external cardioversion doses are 0.5–1.0J/kg and subsequently up to 2J/kg, internal cardioversion doses are 0.5J/kg.

An evaluation of bag-valve-mask ventilation using an ergonomically designed facemask among novice users: A simulation-based pilot study - Corrected Proof

2010-06-18

Abstract: Purpose: We sought to compare the ability of novice operators to provide artificial ventilation using a standard facemask and a new ergonomically designed facemask. Whether or not proper technique was used was also assessed.Methods: Thirty-two allied-health students used both masks in random crossover fashion to ventilate an airway trainer. Breaths were delivered by a mechanical ventilator and exhaled tidal volume was recorded for each of 12 breaths for each participant for each mask. The effect of each mask during ventilation over time was assessed using repeated-measures ANOVA. Assessment of mask technique among participants and association between mask type and hand repositioning were analyzed using the Wilcoxon-Rank Sum Test and McNemar's paired proportions test, respectively.Results: The tidal volume achieved when participants used the ergonomic mask was higher than when participants used the standard mask by the fourth breath (361±104mL vs. 264±163mL; Bonferroni adjusted p-value=0.040) and increased over time. The repeated-measures ANOVA showed that the ergonomic mask consistently resulted in higher tidal volumes than the standard mask regardless of rescuer's gender. Over time the standard mask resulted in a linear decrease in tidal volume of −10mL/breath (estimated difference in decay of 10mL/breath versus the ergonomic mask; p<0.001).Conclusion: Novice airway operators were better able to provide facemask ventilation using an ergonomically designed mask than with a traditional facemask. We conclude that better hand position facilitating improved mask seal and less operator fatigue account for our findings.

Mechanical ventilators in the hot zone: Effects of a CBRN filter on patient protection and battery life - Corrected Proof

Thomas C. Blakeman, Peter Toth, Dario Rodriquez, Richard D. Branson — 2010-06-18

Abstract: Objective: In a contaminated environment, respiratory protection for ventilator dependent patients can be achieved by attaching a chemical, biological, radiological, or nuclear (CBRN) filter to the air intake port of a portable ventilator. We evaluated the effect of the filter on battery performance of four portable ventilators in a laboratory setting.Methods: Each ventilator was attached to a test lung. Ventilator settings were: assist control (AC) mode, respiratory rate 35bpm, tidal volume 450ml, positive end-expiratory pressure (PEEP) 10cm H2O, inspiratory time 0.8s, and FIO2 0.21. Ventilators were operated until the battery was fully discharged. We also evaluated the ventilators’ ability to deliver all the gas through the CBRN filter and analyzed the pressures required to breathe through the anti-asphyxiation valve of a failed device.Results: The range of battery life varied widely across different ventilator models (99.8–562.6min). There was no significant difference in battery life (p<0.01) when operating with or without the CBRN filter attached. Only the Impact 731 routed all inspired gases through the CBRN filter. The pressure required to breathe though the failed device was −4cm H2O to −9cm H2O.Conclusions: Duration of operation from the internal battery was not altered by attachment of the CBRN filter. The use of a CBRN filter is necessary for protection of ventilator dependent patients when environmental contamination is present, although conditions exist where all gas does not pass through the filter with some ventilators under normal operating conditions.

Scientific, legal, and ethical challenges of end-of-life organ procurement in emergency medicine - Corrected Proof

Mohamed Y. Rady, Joseph L. Verheijde, Joan L. McGregor — 2010-06-18

Abstract: Aim: We review (1) scientific evidence questioning the validity of declaring death and procuring organs in heart-beating (i.e., neurological standard of death) and non-heart-beating (i.e., circulatory–respiratory standard of death) donation; (2) consequences of collaborative programs realigning hospital policies to maximize access of procurement coordinators to critically and terminally ill patients as potential donors on arrival in emergency departments; and (3) ethical and legal ramifications of current practices of organ procurement on patients and their families.Data sources: Relevant publications in peer-reviewed journals and government websites.Results: Scientific evidence undermines the biological criteria of death that underpin the definition of death in heart-beating (i.e., neurological standard) and non-heart-beating (i.e., circulatory–respiratory standard) donation. Philosophical reinterpretation of the neurological and circulatory–respiratory standards in the death statute, to avoid the appearance of organ procurement as an active life-ending intervention, lacks public and medical consensus. Collaborative programs bundle procurement coordinators together with hospital staff for a team-huddle and implement a quality improvement tool for a Rapid Assessment of Hospital Procurement Barriers in Donation. Procurement coordinators have access to critically ill patients during the course of medical treatment with no donation consent and with family or surrogates unaware of their roles. How these programs affect the medical care of these patients has not been studied.Conclusions: Policies enforcing end-of-life organ procurement can have unintended consequences: (1) erosion of care in the patient's best interests, (2) lack of transparency, and (3) ethical and legal ramifications of flawed standards of declaring death.

Quality of chest compressions during continuous CPR; comparison between chest compression-only CPR and conventional CPR - Corrected Proof

2010-06-18

Abstract: Objectives: This study aimed to compare the time-dependent deterioration of chest compressions between chest compression-only cardiopulmonary resuscitation (CPR) and conventional CPR.Methods: This study involved 106 and 107 participants randomly assigned to chest compression-only CPR training and conventional CPR training, respectively. Immediately after training, participants were asked to perform CPR for 2min and the quality of their CPR skills were evaluated. The number of chest compressions in total and those with appropriate depth were counted every 20-s CPR period from the start of CPR. The primary outcome was the CPR quality index calculated as the proportion of chest compressions with appropriate depth among total chest compressions.Results: The total number of chest compressions remained stable over time both in the chest compression-only and the conventional CPR groups. The CPR quality index, however, decreased from 86.6±25.0 to 58.2±36.9 in the chest compression-only CPR group from 0–20s through 61–80s. The reduction was greater than in the conventional CPR group (85.9±25.5 to 74.3±34.0). The difference in the CPR quality index reached statistical significance (p=0.003) at 61–80s period.Conclusions: Chest compressions with appropriate depth decreased more rapidly during chest compression-only CPR than conventional CPR. We recommend that CPR providers change their roles every 1min to maintain the quality of chest compressions during chest compression-only CPR. (UMIN-CTR C0000000321)

Does position of the patient adversely affect successful intubation whilst wearing CBRN-PPE? - Corrected Proof

Nicholas Castle, Robert Owen, Simon Clarke, Mark Hann, David Reeves, Ian Gurney — 2010-06-18

Abstract: Introduction: Following a CBRN incident attending medical personnel will be required to instigate life saving airway interventions whilst wearing CBRN-PPE. CBRN-PPE is known to adversely affect fine motor skill but little is known about whether the position of the patient compounds this problem.Methods: Seventy-five clinicians were recruited and performed intubation and insertion of a LMA in to a manikin whilst wearing CBRN-PPE. Both skills were completed twice with the manikin positioned on a bench and once on the floor. Following completion of the study 25 participants (a minimum of 2 participants from each professional group) were interviewed to ascertain their experiences. The recruitment of a non-homogenous group allowed for subgroup analysis with regards the potential impact of professional background on skill performance.Results: 9.33% first attempts at intubation at waist height ended in failure but this reduced to 4% on the second attempt. This improvement was reversed with the manikin on the floor where the failure rate was 26.67%. Intubation on the floor took significantly longer to perform, being 45.9s slower than the first attempt at intubation in the optimal position [95% CI (30.7s, 61.1s); p<0.001] and 62.4s longer than the second [95% CI (48.4s, 76.3s); p<0.001]. LMA insertion was successful at all attempts, regardless of the manikins position. LMA placement on the floor was no slower than the second attempt at waist height (p=0.231) and faster than the first attempt at waist height (by 4.8s [95% CI (3.4s, 6.1s); p<0.001]). Anaesthetists were consistently the fastest at performing all airway skills regardless of the position of the manikin but previous exposure to wearing CBRN-PPE had no statistically significant impact on skill performance. All 25 clinicians interviewed had difficulty in viewing the larynx with the manikin positioned on the floor regardless of being an experienced ‘on floor’ intubator with the movement of the CBRN-PPE hood being the principle reason. This is in contrast to only three participants noting issues with vision whilst standing-up.Conclusion: the position of the patient is likely to be an independent factor when choosing to either intubate or insert a LMA whilst wearing the current NHS CBRN-PPE.

Cardiopulmonary resuscitation artefact suppression using a Kalman filter and the frequency of chest compressions as the reference signal - Corrected Proof

Jesus Ruiz, Unai Irusta, Sofia Ruiz de Gauna, Trygve Eftestøl — 2010-06-18

Abstract: Aim: To develop a new method to suppress the artefact generated by chest compressions during cardiopulmonary resuscitation (CPR) using only the frequency of the compressions as additional information.Materials and methods: The CPR artefact suppression method was developed and tested using a database of 381 ECG records (89 shockable and 292 non-shockable) from 299 patients. All records were extracted from real out-of-hospital cardiac arrest episodes. The suppression method consists of a Kalman filter that uses the frequency of the measured compressions to estimate the artefact and to remove it from the ECG. The performance of the filter was evaluated by comparing the sensitivity and specificity of an automated external defibrillator before and after the artefact suppression.Results: For the test database, the sensitivity improved from 57.8% (95% confidence interval, 43.3–71.0%) to 93.3% (81.5–98.4%) and the specificity decreased from 92.5% (87.0–95.9%) to 89.1% (83.0–93.3%).Conclusion: For a similar sensitivity, we obtained better specificity than that reported for other methods, although still short of the values recommended by the American Heart Association. The results suggest that the CPR artefact can be accurately modelled using only the frequency of the compressions. This information could be easily acquired through the defibrillator's CPR help pads, with minimal hardware modifications.

Epidemiology of paediatric out-of-hospital cardiac arrest in Melbourne, Australia - Corrected Proof

2010-06-03

Abstract: Background: Previous studies of paediatric cardiac arrest have reported a low survival rate but there is limited data from Australia. We sought to determine the characteristics and outcomes of paediatric out-of-hospital cardiac arrest in Melbourne, Australia.Methods: Between October 1999 and June 2007, all cases of out-of-hospital cardiac arrest attended by emergency medical services in Melbourne, Australia were entered into a database (the Victorian Ambulance Cardiac Arrest Registry). Data on patients aged less than 16 years in cardiac arrest on arrival of ambulance paramedics was analysed.Results: There were 209 children in cardiac arrest on arrival of paramedics during the study period. Of these, resuscitation was not attempted in 16 children due to signs of definite death. Of the 193 children who had attempted resuscitation, 143 (74%) had an initial cardiac rhythm of asystole, 36 (18%) were in pulseless electrical activity and 14 (7%) were in ventricular fibrillation. There were 49 patients (25%) with return of spontaneous circulation at arrival to hospital of whom 14 (7%) survived to hospital discharge. Of 138 patients without return of a circulation, 120 were transported to hospital with continuing resuscitation and one survived (0.9%). Survival was higher in patients with an initial cardiac rhythm of ventricular fibrillation (5/14; 35%) compared with other rhythms (10/179; 4%), OR 9.38, 95% CI 2.64–33.2.Conclusions: Overall, 7.7% of paediatric patients with out-of-hospital cardiac arrest survive to leave hospital. Increased survival was seen if the initial cardiac rhythm was ventricular fibrillation. Survival was very rare (<1%) unless there was return of spontaneous circulation prior to hospital arrival.

Using extracorporeal life support to resuscitate adult postcardiotomy cardiogenic shock: Treatment strategies and predictors of short-term and midterm survival - Corrected Proof

2010-06-03

Abstract: Background: Postcardiotomy extracorporeal life support (ECLS) is a resource-demanding therapy with varied results among institutions. An organized protocol was necessary to improve the effectiveness of this therapy.Methods and results: A total of 110 patients received ECLS due to refractory postcardiotomy cardiogenic shock between January 2003 and June 2009, and were eligible for inclusion in this retrospective study. Preoperative, perioperative, and postoperative variables were collected, including the European system for cardiac operative risk evaluation (EuroSCORE) and markers of ECLS-related organ injuries. All variables were analyzed for possible associations with mortality in hospital, and after hospital discharge. The mean age, additive EuroSCORE, and left ventricular ejection fraction (LVEF) for all patients was 60 (±14) years, 9 (±6), and 43% (±20%) respectively. Sixty-seven patients were weaned from ECLS and 46 survived to hospital discharge. The mean duration of ECLS support was 143h (±112h). Multivariate analysis revealed that an age of >60 years, a necessity for postoperative continuous arteriovenous hemofiltration, a maximal serum total bilirubin >6mg/dL, and a need for ECLS support for >110h were independent predictors of in-hospital mortality. In addition, persistent heart failure with LVEF <30% was an independent predictor of mortality after hospital discharge. A risk-predicting score for in-hospital mortality associated with postcardiotomy ECLS was developed for clinical application.Conclusion: Based on the abovementioned findings, a comprehensive protocol for postcardiotomy ECLS was designed. The primary objective was to achieve adequate hemodynamics within the first 24h of initiating ECLS. Other objectives of the protocol included a consistent approach to safe anticoagulation while on ECLS, a process to make decisions within 7 days of initiating ECLS, and patient follow-up after hospital discharge.