Resuscitation

Better ViEWS ahead? It is high time to improve patient safety by standardizing Early Warning Scores

Christian Peter Subbe — 2010-08-01

The contribution by Prytherch et al. in this issue represents a major advance in the way early warning scores are used to identify patients at risk of catastrophic deterioration and cardiorespiratory arrest on general wards. In turn, this will impact the efficiency of rapid response systems (RRS).

Delayed versus immediate defibrillation for out-of-hospital cardiac arrest due to ventricular fibrillation: A systematic review and meta-analysis of randomised controlled trials

Paul M. Simpson, Mark S. Goodger, Jason C. Bendall — 2010-05-19

Abstract: Background: Human studies over the last decade have indicated that delaying initial defibrillation to allow a short period of cardiopulmonary resuscitation (CPR) may promote a more responsive myocardial state that is more likely to respond to defibrillation and result in increased rates of restoration of spontaneous circulation (ROSC) and/or survival. Out-of-hospital studies have produced conflicting results regarding the benefits of CPR prior to defibrillation in relation to survival to hospital discharge. The aim of this study was to conduct a systematic review and meta-analysis of randomised controlled trials comparing the effect of delayed defibrillation preceded by CPR with immediate defibrillation on survival to hospital discharge.Methods: A systematic literature search of key electronic databases including Medline, EMBASE, and the Cochrane Library was conducted independently by two reviewers. Randomised controlled trials meeting the eligibility criteria were critically appraised according to the Cochrane Group recommended methodology. Meta-analyses were conducted for the outcomes of survival to hospital discharge overall and according to response time of emergency medical services.Results: Three randomised controlled trials were identified which addressed the question of interest. All included studies were methodologically appropriate to include in a meta-analysis. Pooled results from the three studies demonstrated no benefit from providing CPR prior to defibrillation compared to immediate defibrillation for survival to hospital discharge (OR 0.94 95% CI 0.46–1.94). Meta-analysis of results according to ambulance response time (≤5min or >5min) also showed no difference in survival rates.Conclusion: Delaying initial defibrillation to allow a short period of CPR in out-of-hospital cardiac arrest due to VF demonstrated no benefit over immediate defibrillation for survival to hospital discharge irrespective of response time. There is no evidence that CPR before defibrillation is harmful. Based on the existing evidence, EMS jurisdictions are justified continuing with current practice using either defibrillation strategy.

ViEWS—Towards a national early warning score for detecting adult inpatient deterioration

David R. Prytherch, Gary B. Smith, Paul E. Schmidt, Peter I. Featherstone — 2010-08-01

Abstract: Aim of study: To develop a validated, paper-based, aggregate weighted track and trigger system (AWTTS) that could serve as a template for a national early warning score (EWS) for the detection of patient deterioration.Materials and methods: Using existing knowledge of the relationship between physiological data and adverse clinical outcomes, a thorough review of the literature surrounding EWS and physiology, and a previous detailed analysis of published EWSs, we developed a new paper-based EWS – VitalPAC™ EWS (ViEWS). We applied ViEWS to a large vital signs database (n=198,755 observation sets) collected from 35,585 consecutive, completed acute medical admissions, and also evaluated the comparative performance of 33 other AWTTSs, for a range of outcomes using the area under the receiver-operating characteristics (AUROC) curve.Results: The AUROC (95% CI) for ViEWS using in-hospital mortality with 24h of the observation set was 0.888 (0.880–0.895). The AUROCs (95% CI) for the 33 other AWTTSs tested using the same outcome ranged from 0.803 (0.792–0.815) to 0.850 (0.841–0.859). ViEWS performed better than the 33 other AWTTSs for all outcomes tested.Conclusions: We have developed a simple AWTTS – ViEWS – designed for paper-based application and demonstrated that its performance for predicting mortality (within a range of timescales) is superior to all other published AWTTSs that we tested. We have also developed a tool to provide a relative measure of the number of “triggers” that would be generated at different values of EWS and permits the comparison of the workload generated by different AWTTSs.

Incidence of re-arrest and critical events during prolonged transport of post-cardiac arrest patients

A. Hartke, B.E. Mumma, J.C. Rittenberger, C.W. Callaway, F.X. Guyette — 2010-05-20

Abstract: Aim: To determine the feasibility of transporting post-cardiac arrest patients to tertiary-care facilities, the rate of re-arrest, and the rate of critical events during critical care transport team (CCTT) care.Methods: Retrospective chart review of cardiac arrest patients transported via CCTT between 1/1/2001 and 5/31/2009. Demographic information, re-arrest, and critical events during transport were abstracted. We defined critical events as hypotension (systolic blood pressure<90mmHg), hypoxia (oxygen saturation<90%), or both hypotension and hypoxia at any time during CCTT care. Comparisons were performed using Chi-squared test and a Cox proportional hazards model was employed to determine predictors of events.Results: Of the 248 patients studied, the majority was male (61%), presented in ventricular fibrillation or ventricular tachycardia (VF/VT, 50%), and comatose (80%). Re-arrest was uncommon (N=15; 6%). Critical events affected 58 patients (23%) during transport. Median transport time was 63min (IQR 51, 81) in both those who experienced a critical event and those who did not. Vasopressor use was associated with any decompensation during CCTT (Hazard Ratio 1.81; 95%CI 1.29, 2.54). Three patients (20%) suffering re-arrest survived to hospital discharge. Survival (Chi square 11.77; p<0.01) and good neurologic outcome (Chi square 5.93; p=0.01) were higher in patients who did not suffer any event during transport.Conclusions: Transport of resuscitated cardiac arrest patients to a tertiary-care facility via CCTT is feasible, and the duration of transport is not associated with re-arrest during transport. Repeat cardiac arrest occurs infrequently, while critical events are more common. Outcomes are worse in those experiencing an event.

Safety and feasibility of nasopharyngeal evaporative cooling in the emergency department setting in survivors of cardiac arrest

2010-06-03

Abstract: Aim: Mild therapeutic hypothermia improves survival and neurologic recovery in primary comatose survivors of cardiac arrest. Cooling effectivity, safety and feasibility of nasopharyngeal cooling with the RhinoChill device (BeneChill Inc., San Diego, USA) were determined for induction of therapeutic hypothermia.Methods: Eleven emergency departments and intensive care units participated in this multi-centre, single-arm descriptive study. Eighty-four patients after successful resuscitation from cardiac arrest were cooled with nasopharyngeal delivery of an evaporative coolant for 1h. Subsequently, temperature was controlled with systemic cooling at 33°C. Cooling rates, adverse events and neurologic outcome at hospital discharge using cerebral performance categories (CPC; CPC 1=normal to CPC 5=dead) were documented. Temperatures are presented as median and the range from the first to the third quartile.Results: Nasopharyngeal cooling for 1h reduced tympanic temperature by median 2.3 (1.6; 3.0)°C, core temperature by 1.1 (0.7; 1.5)°C. Nasal discoloration occurred during the procedure in 10 (12%) patients, resolved in 9, and was persistent in 1 (1%). Epistaxis was observed in 2 (2%) patients. Periorbital gas emphysema occurred in 1 (1%) patient and resolved spontaneously. Thirty-four of 84 patients (40%) patients survived, 26/34 with favorable neurological outcome (CPC of 1–2) at discharge.Conclusions: Nasopharyngeal evaporative cooling used for 1h in primary cardiac arrest survivors is feasible and safe at flow rates of 40–50L/min in a hospital setting.

Circadian variation of human ventricular fibrillation dominant frequency

Philip Langley, Guy A. MacGowan, Alan Murray — 2010-04-26

Abstract: Aim: Circadian variation in human ventricular fibrillation (VF) dominant frequency is unknown. If present this would provide evidence of physiological influence on VF. The objective was to quantify the circadian variation in human VF dominant frequency.Methods: Eight-lead Holter ECG recordings were obtained from a patient with severe myocarditis and chronic VF who was supported by a biventricular assist device. Recordings of up to 24h duration were obtained on 6 days with an average interval between recordings of 7 days. Dominant frequency and amplitude were obtained using spectral analysis and assessed for (i) circadian (ii) inter-recording and (iii) inter-lead differences.Results: There was a significant circadian variation in amplitude (night: 0.027±0.004mVHz vs day: 0.044±0.006mVHz, p<0.0001) but not dominant frequency (night: 7.85±0.62Hz vs day: 7.93±0.54Hz, p>0.05). There were significant differences between recordings in dominant frequency which ranged from 6.80±0.29Hz to 8.36±0.38Hz (p<0.0001) and dominant frequency spectral amplitude which ranged from 0.033±0.014mVHz to 0.043±0.017mVHz (p<0.0001). Histograms of dominant frequencies in leads exhibited strikingly different distributions, particularly in V2 that was characterised by a bimodal distribution, while the other leads were characterised by predominantly unimodal distributions.Conclusion: VF dominant frequency spectral amplitude exhibited circadian variability. In a patient with severe myocarditis, supported with a biventricular assist device and in chronic VF, these results provide evidence for modulation of VF, probably induced by changes in posture and physical activity.

Incidence and outcomes of out-of-hospital cardiac arrest with shock-resistant ventricular fibrillation: Data from a large population-based cohort

2010-05-31

Abstract: Background: The increasing survival rates after out-of-hospital cardiac arrests (OHCA) are due mainly to improvements in the first 3 steps of the chain of survival. The aim of this study was to describe the temporal trends of OHCA incidence and outcomes with shock-resistant ventricular fibrillation (VF) requiring advanced life support procedures.Methods: All our subjects were persons aged 18 years or more who had suffered OHCA of presumed cardiac etiology, were witnessed by bystanders, treated by emergency medical service (EMS), and had VF as initial rhythm. Our study was conducted in Osaka Prefecture, Japan from May 1, 1998 through December 31, 2006. Data were collected by EMS personnel using an Utstein-style database. We evaluated the temporal trends of incidence and outcomes of shock-resistant VF.Results: During the study period, there were 8782 witnessed OHCA cases of presumed cardiac etiology. Among them, 1733 had VF as an initial rhythm, 392 of whom were shock-resistant. While the age-adjusted annual incidence of witnessed VF increased from 2.0 to 3.3 per 100,000 inhabitants, that of shock-resistant VF underwent little change during the study period. The proportion of shock-resistant VF among witnessed VF decreased from 37.0% to 19.0%. Neurologically intact 1-month survival rates after shock-resistant VF remained low at 5.6% even in 2006.Conclusion: The actual incidence of shock-resistant VF has remained unchanged, and their outcomes continue to be dismal. Further efforts are required to reduce the mortality rates of such shock-resistant VF to achieve improved survival after OHCA.

Survival and health care costs until hospital discharge of patients treated with onsite, dispatched or without automated external defibrillator

2010-06-04

Abstract: Background: This study aimed to determine whether automated external defibrillator (AED) use during resuscitation is associated with lower in-hospital health care costs.Methods: For this observational prospective study, we included all treated out-of-hospital cardiac arrests of suspected cardiac cause. Clinical, survival and cost data were collected from July 2005 until March 2008. Cost data were based on hospital transport, duration of admission in hospital wards, diagnostics and interventions. We divided the study population in three groups based on AED use: (1) onsite AED, (2) dispatched AED, (3) no AED. The endpoint was survival to discharge. P<0.05 is indicated by *.Results: Of the 2126 included patients, 136 were treated with an onsite AED, 365 with a dispatched AED and 1625 without AED. Overall (95% confidence interval [CI]) survival rate was 43% (35–51%), 16% (13–20%) and 14% (12–16%), respectively*. Per 100 survivors, the mean duration admitted at intensive care unit [ICU] were 267 (166–374), 495 (344–658), and 537 (450–609) days, respectively*; total duration of hospital admission was 2188 (1800–2594), 3132 (2573–3797), and 2765 (2519–3050) days, respectively*. Mean costs per survivor for hospital stay were €9233 (€7351–€11,280), €14,194 (€11,656–€17,254), and €13,693 (€12,226–€15,166), respectively*; total health care costs were €29,575 (€24,695–€34,183), €34,533 (€29,832–€39,487) and €31,772 (€29,217–€34,385), respectively. For both survivors and non-survivors, total costs per patient were €14,727 (€11,957–€18,324), €7703 (€6141–€9366) and €6580 (€5875–€7238), respectively*.Conclusions: Onsite AED use was associated with higher survival rates. Surviving patients of the onsite AED group had lower total costs, mainly due to the shorter ICU stay.

Assessment of outcomes and differences between in- and out-of-hospital cardiac arrest patients treated with cardiopulmonary resuscitation using extracorporeal life support

2010-06-03

Abstract: Aim: Cardiopulmonary resuscitation (CPR) using extracorporeal life support (ECLS) for in-hospital cardiac arrest (IHCA) patients has been assigned a low-grade recommendation in current resuscitation guidelines. This study compared the outcomes of IHCA and out-of-hospital cardiac arrest (OHCA) patients treated with ECLS.Methods: A total of 77 patients were treated with ECLS. Baselines characteristics and outcomes were compared for 38 IHCA and 39 OCHA patients.Results: The time interval between collapse and starting ECLS was significantly shorter after IHCA than after OHCA (25 (21–43)min versus 59 (45–65)min, p<0.001). The weaning rate from ECLS (61% versus 36%, p=0.03) and 30-day survival (34% versus 13%, p=0.03) were higher for IHCA compared with OHCA patients. IHCA patients had a higher rate of favourable neurological outcome compared to OHCA patients, but the difference was not statistically significant (26% versus 10%, p=0.07). Kaplan–Meier analysis showed improved 30-day and 1-year survival for IHCA patients treated with ECLS compared to OHCA patients who had ECLS. However, multivariate stepwise Cox regression model analysis indicated no difference in 30-day (odds ratio 0.94 (95% confidence interval 0.68–1.27), p=0.67) and 1-year survival (0.99 (0.73–1.33), p=0.95).Conclusion: CPR with ECLS led to more favourable patient outcomes after IHCA compared with OHCA in our patient group. The difference in outcomes for ECLS after IHCA and OHCA disappeared after adjusting for patient factors and the time delay in starting ECLS.

Epidemiology and outcomes from non-traumatic out-of-hospital cardiac arrest in Korea: A nationwide observational study

2010-06-04

Abstract: Objectives: We aimed to describe the epidemiological features and to determine the predictors for survival to discharge of non-traumatic out-of-hospital cardiac arrest (OHCA) in Korea.Subjects and methods: A nationwide Utstein style OHCA database (2006–2007) was constructed from ambulance records and hospital medical record review. Cases were enrolled when they were non-traumatic OHCA with presumed cardiac aetiology. Using the population census (2005), we calculated age–gender standardized incidence rates (SIR) and mortality (SMR). We modelled a multivariate logistic regression analysis to determine the effect of risk factors on hospital outcomes.Results: The total number of EMS-assessed non-traumatic OHCA patients was 19045. The SIR was 20.9 (2006) and 22.2 (2007) per 100000 and survival-to-discharge rate was 2.3% for EMS-assessed non-traumatic OHCA, and was 3.5% for the resuscitation-attempted group. From a multivariate logistic regression analysis, witnessed arrest, and shorter basic life support (BLS) and EMS intervals turned out to be significant predictors of good outcome in the resuscitation-attempted group.Conclusion: From a nationwide OHCA cohort, the incidence of EMS-assessed non-traumatic OHCA was found to be low. Survival-to-discharge rate in the resuscitation-attempted group was 3.5%, which was significantly associated with witnessed arrest, and shorter BLS and EMS intervals.

Experiences of sudden cardiac arrest survivors regarding prognostication and advance care planning

2010-05-04

Abstract: Objective: We sought to better understand SCA survivors’ beliefs about complex issues that arise in the immediate post-arrest period and explore advance care planning. Specifically, we wished to explore four themes: (1) patient and family perception of medical providers’ prognostication in the immediate post-arrest phase; (2) patient definitions of death; (3) use of advance directives (ADs); and (4) perceptions of health and organ donation.Methods: We conducted a qualitative study of adult arrest survivors using semi-structured telephone interviews. Participants were recruited from a nonprofit national organization for SCA.Results: Nine of 11 subjects contacted completed the survey. In the immediate post-arrest phase, subjects believed that medical professionals made errors in giving poor prognosis early in the course of resuscitation. While some subjects felt they had experienced “death,” some subjects felt the term “death” was an inappropriate term to describe their experience. The majority of the subjects did not have an AD prior to their SCA and no subjects reported having a conversation about ADs with their medical team. While the majority of subjects classified their health as “very good” or “excellent,” few subjects were registered organ donors, citing comorbidities and skepticism about future resuscitative efforts as rationale.Conclusions: Our study elucidated the attitudes and experiences of SCA survivors. Variability in prognostication timing and inconsistency in describing SCA can complicate discussions between the medical team and families. AD and organ donation discussions may help to provide sensitive care concordant with a patient's wishes.

Oxygen transport characterization of a human model of progressive hemorrhage

2010-04-26

Abstract: Background: Hemorrhage continues to be a leading cause of death from trauma sustained both in combat and in the civilian setting. New models of hemorrhage may add value in both improving our understanding of the physiologic responses to severe bleeding and as platforms to develop and test new monitoring and therapeutic techniques. We examined changes in oxygen transport produced by central volume redistribution in humans using lower body negative pressure (LBNP) as a potential mimetic of hemorrhage.Methods and results: In 20 healthy volunteers, systemic oxygen delivery and oxygen consumption, skeletal muscle oxygenation and oral mucosa perfusion were measured over increasing levels of LBNP to the point of hemodynamic decompensation. With sequential reductions in central blood volume, progressive reductions in oxygen delivery and tissue oxygenation and perfusion parameters were noted, while no changes were observed in systemic oxygen uptake or markers of anaerobic metabolism in the blood (e.g., lactate, base excess). While blood pressure decreased and heart rate increased during LBNP, these changes occurred later than the reductions in tissue oxygenation and perfusion.Conclusions: These findings indicate that LBNP induces changes in oxygen transport consistent with the compensatory phase of hemorrhage, but that a frank state of shock (delivery-dependent oxygen consumption) does not occur. LBNP may therefore serve as a model to better understand a variety of compensatory physiological changes that occur during the pre-shock phase of hemorrhage in conscious humans. As such, LBNP may be a useful platform from which to develop and test new monitoring capabilities for identifying the need for intervention during the early phases of hemorrhage to prevent a patient's progression to overt shock.

Comparison of two intraosseous access devices in adult patients under resuscitation in the emergency department: A prospective, randomized study

2010-05-03

Abstract: Introduction: Current guidelines recommend intraosseous (IO) vascular access in adults if peripheral venous access is unavailable. Most available data derive from children, animal models, cadaver studies or the prehospital setting. Therefore we compared two different IO access devices in adults under resuscitation in the hospital setting.Patients and methods: This prospective, randomized clinical study compared two different IO access devices in adults (≥18 years of age) under trauma or medical resuscitation admitted to our emergency department with impossible peripheral venous access. Each adult was randomized to either spring-loaded BIG Bone Injection Gun or battery-powered EZ-IO. Outcome measures included success rates on first attempt, procedure times and complications.Results: Forty consecutive adults under resuscitation were enrolled. Twenty patients received the BIG, another twenty patients the EZ-IO. Over all success rate on first attempt was 85% and mean procedure time 2.0min±0.9. Comparing the two devices, success rate on first attempt was 80% for the BIG versus 90% for the EZ-IO and mean procedure time was 2.2min±1.0 for the BIG versus 1.8min±0.9 for the EZ-IO. The differences between both IO devices were not statistically significant. No other relevant complications like infection, extravasation or bleeding were observed.Conclusions: IO vascular access was a reliable and safe method to gain rapid vascular access for in-hospital adult emergency patients under resuscitation. Further studies are necessary regarding comparative effectiveness of different IO devices.

A randomised, simulated study assessing auscultation of heart rate at birth

2010-05-19

Abstract: Background: Heart rate is a primary clinical indicator directing newborn resuscitation. The time taken to assess the heart rate by auscultation in relation to accuracy during newborn resuscitation is not known.Objective: To assess both the accuracy and time taken to assess heart rate by stethoscope in simulated resuscitation scenarios.Method: The VitalSim© manikin (Laerdal Medical, Stavanger, Norway) was used in this randomised, single blind study. Four heart rate settings (0, 40, 80, 120 beats per minute (bpm)) were randomly assigned. Participants assessed them by auscultation in three different scenarios. The first scenario was to assess the actual heart rate at birth. In the second scenario, heart rate was assessed during ventilation and assigned to standard ranges (<60, 60–100, >100bpm). In the third scenario, heart rate was assessed after three cycles of compressions and ventilation and assigned to standard ranges.Results: In total 61 midwives, nurses and doctors performed 183 assessments. Mean time to estimate heart rate for scenarios 1, 2 and 3 was: 17.0, 9.8 and 7.8s respectively. Heart rate assessments were inaccurate in 31% (scenario 1), 28% (scenarios 2) and 26% (scenario 3). There was a trend for assessors who were accurate to be quicker and this achieved significance in scenario 2 (p<0.02). Inaccurate assessment would have made a difference to management in 28% of all cases.Conclusions: Mean time to estimate heart rate for the scenarios varied between 7.8 and 17.0s. Twenty-eight percent of all heart rate assessments would have prompted incorrect management during resuscitation or stabilization. Of incorrect assessments, 73% were overestimations. Further research is required to develop a rapid and accurate method for determining heart rate during newborn resuscitation.

Comparison of instructor-led automated external defibrillation training and three alternative DVD-based training methods

2010-05-20

Abstract: Background: Self-directed BLS-training, using a personal training manikin with video has been shown to be as effective as instructor-led training. This has not previously been investigated for AED-training.Materials and methods: This prospective, randomized study with a non-inferiority design compared traditional instructor-led training with three DVD-based AED-training methods (2.5min DVD without practice; 4.5min DVD with manikin practice; 9min DVD with manikin practice and scenario training). After DVD BLS-training, 396 participants were assigned to one of the four AED-training methods by randomization stratified for age.Participants were tested immediately after the training (post-test) and 2 months later (retention-test) using modified Cardiff criteria. The primary endpoint was the percentage of providers scoring 70% or higher on testing. The secondary endpoints were the mean scores and differences per item per age group.Results: Comparison non-inferiority could not be accepted for the post-test or retention-test. Relative risk (RR) and 95% confidence interval (CI) of passing for DVD without practice, with manikin practice and with manikin practice and scenario training compared to instructor-led training were 0.36 (0.25–0.53), 0.35 (0.24–0.51), 0.55 (0.38–0.79), respectively for the post-test, and 0.82 (0.68–0.97), 0.82 (0.68–0.97), and 0.84 (0.70–1.00), respectively for the retention-test. The performance of participants in all DVD-based training groups was significantly higher on the retention-test than on the post-test. Those receiving scenario training scored higher on the post-test compared to the other DVD-training groups (p<0.001).Conclusions: DVD-based AED-training without scenario is not recommended. Scenario training is a useful addition, but instructor-facilitated training remains the best method.

Influence of an impedance threshold valve on ventilation with supraglottic airway devices during cardiopulmonary resuscitation in a manikin

H.V. Genzwuerker, C. Gernoth, J. Hinkelbein, W. Schmidbauer, T. Kerner — 2010-05-17

Abstract: Aim This study investigates if a n impedance threshold valve (ITV) might improve survival after cardiac arrest by increasing vital organ blood flow. The combination of ITV and supraglottic airway devices (SADs) has not been previously studied. This simulation study in a manikin aimed at analysing differences in ventilation with different SADs without and with an ITV.Methods: In a resuscitation manikin, cardiopulmonary resuscitation (CPR) was performed with interrupted (30:2) and continuous chest compressions using facemask, tracheal tube and 10 SADs (six different laryngeal masks, LT-D, LTS-D, Combitube® and Easy Tube®). Ventilation was performed with and without an ITV. A total of 550 CPR cycles of 3-min duration were performed with chest compressions and ventilation standardised by use of a mechanical thumper device and an emergency ventilator.Results: Sufficient ventilation was possible with all devices tested. For ventilation during continuous chest compressions, there were significantly reduced tidal volumes for all airway devices with ITV use. By contrast, during interrupted chest compressions, no differences in tidal volumes with the ITV occurred in the majority of devices. The maximum reduction of tidal volume for any device was 7.8% of the volume reached without the ITV.Conclusion: Based on the findings of this manikin trial, the use of an ITV for ventilation during CPR is possible in combination with supraglottic airway devices. Merging these two strategies warrants further clinical evaluation to judge the relevance of tidal volume reduction found in this trial.

Effect of cardiopulmonary resuscitation on intubation using a Macintosh laryngoscope, the AirWay Scope, and the gum elastic bougie: A manikin study

2010-06-02

Abstract: Background: Physicians could encounter difficult intubation during cardiopulmonary resuscitation (CPR) in trauma patients due to the patient's movement from continuous chest compression and to cervical stabilisation. Therefore, first, we evaluated the impact of chest compression with or without cervical stabilisation on intubation with a Macintosh laryngoscope. Next, we compared difficulty in intubation among the Macintosh laryngoscope, AirWay Scope (AWS), and gum elastic bougie (GEB) with the Macintosh laryngoscope in three simulated CPR scenarios in a randomised, controlled, cross-over study design.Methods: Twenty-three anaesthetists intubated the trachea of a manikin (ALS Skill Master, Laerdal Medical Japan, Tokyo, Japan) using the Macintosh laryngoscope, AWS, and GEB in the control scenario, chest compression scenario, and chest compression with cervical stabilisation scenario. Difficulty in intubation was rated on a 5-point scale and the intubation time was measured.Results: Continuous chest compression increased difficulty in intubation with the Macintosh laryngoscope, compared with the control scenario. Concurrent application of cervical stabilisation further increased the difficulty, compared with application of chest compression alone. Of the three devices compared, the AWS facilitated the easiest intubation, and the GEB facilitated the second-easiest intubation in all scenarios, though the intubation time was slightly longer with the GEB than with other devices.Conclusion: CPR employing continuous chest compression with or without cervical stabilisation caused difficult intubation with the Macintosh laryngoscope. The AWS and GEB facilitated the easiest and second-easiest intubation, respectively, even during CPR employing continuous chest compression with or without cervical stabilisation in a manikin.

Comparison of two instructional modalities for nursing student CPR skill acquisition

Suzan E. Kardong-Edgren, Marilyn H. Oermann, Tamara Odom-Maryon, Yeongmi Ha — 2010-06-03

Abstract: Aims: The purpose of the study was to compare performance based measures of CPR skills (compressions, ventilations with bag-valve-mask (BVM), and single rescuer CPR) from two types of CPR courses: a computer-based course (HeartCode™ BLS) with voice advisory manikin (VAM) feedback and instructor-led (IL) training with traditional manikins.Methods: 604 nursing students from 10 schools of nursing throughout the United States were randomized by school to course type. After successful course completion, students performed 3min each of compressions; ventilations with BVM; and single rescuer CPR on a Laerdal Resusci Anne® SkillReporter™ manikin. The primary outcome measures were: (1) compression rate, (2) percentage of compressions performed with adequate depth, (3) percentage of compressions performed with correct hand placement, (4) number of ventilations/min, and (5) percentage of ventilations with adequate volume.Results: There were no differences in compression rates between the two courses. However, students with HeartCode BLS with VAM training performed more compressions with adequate depth and correct hand placement and had more ventilations with adequate volume than students who had IL courses particularly when learning on hard molded manikins. During single rescuer CPR, students who had HeartCode BLS with VAM training had more compressions with adequate depth and ventilations with adequate volume than students with IL training.Conclusion: Students who trained using HeartCode BLS and practiced with VAMs performed more compressions with adequate depth and ventilations with adequate volume than students who had IL courses. Results of this study provide evidence to support use of HeartCode BLS with VAM for training nursing students in CPR.

Feasibility of intra-arrest hypothermia induction: A novel nasopharyngeal approach achieves preferential brain cooling

Manuel Boller, Joshua W. Lampe, Joseph M. Katz, Denise Barbut, Lance B. Becker — 2010-06-11

Abstract: Aim: In patients with cardiopulmonary arrest, brain cooling may improve neurological outcome, especially if applied prior to or during early reperfusion. Thus it is important to develop feasible cooling methods for pre-hospital use. This study examines cerebral and compartmental thermokinetic properties of nasopharyngeal cooling during various blood flow states.Methods: Ten swine (40±4kg) were anesthetized, intubated and monitored. Temperature was determined in the frontal lobe of the brain, in the aorta, and in the rectum. After the preparatory phase the cooling device (RhinoChill™ system), which produces evaporative cooling in the nasopharyngeal area, was activated for 60min. The thermokinetic response was evaluated during stable anaesthesia (NF, n=3); during untreated cardiopulmonary arrest (ZF, n=3); during CPR (LF, n=4).Results: Effective brain cooling was achieved in all groups with a median cerebral temperature decrease of −4.7°C for NF, −4.3°C for ZF and −3.4°C for LF after 60min. The initial brain cooling rate however was fastest in NF, followed by LF, and was slowest in ZF; the median brain temperature decrease from baseline after 15min of cooling was −2.48°C for NF, −0.12°C for ZF, and −0.93°C for LF, respectively. A median aortic temperature change of −2.76°C for NF, −0.97 for LF and +1.1°C for ZF after 60min indicated preferential brain cooling in all groups.Conclusion: While nasopharyngeal cooling in swine is effective at producing preferential cerebral hypothermia in various blood flow states, initial brain cooling is most efficient with normal circulation.

Comparison of the efficacy of nifekalant and amiodarone in a porcine model of cardiac arrest

Xian-Fei Ji, Chun-Sheng Li, Shuo Wang, Lin Yang, Lu-Hong Cong — 2010-06-04

Abstract: Objective: To compare the efficacy of nifekalant and amiodarone in the treatment of cardiac arrest in a porcine model.Methods: After 4min of untreated ventricular fibrillation, animals were randomly treated with nifekalant (2mgkg−1), amiodarone (5mgkg−1) or saline placebo (n=12 pigs per group). Precordial compression and ventilation were initiated after drug administration and defibrillation was attempted 2min later. Hemodynamics were continuously measured for 6h after successful resuscitation.Results: Compared with saline, nifekalant and amiodarone equally decreased the number of electric shocks, defibrillation energy, epinephrine dose, and duration of cardiopulmonary resuscitation required for successful resuscitation (P<0.01). The incidence of restoration of spontaneous circulation (ROSC) and the 24-h survival rate were higher in both antiarrhythmic drug groups (P<0.05) vs. the saline group. Furthermore, post-resuscitation myocardial dysfunction at 4–6h after successful resuscitation was improved in animals given antiarrhythmic drugs as compared with the saline group (P<0.05). There were no differences between nifekalant and amiodarone for any of these parameters.Conclusion: The effect of nifekalant was similar to that of amiodarone for improving defibrillation efficacy and for the treatment of cardiac arrest. Administration of either nifekalant or amiodarone before defibrillation increased the ROSC and 24-h survival rates and improved post-resuscitation cardiac function in this porcine model.

Intravenous fat emulsion to reverse haemodynamic instability from intentional amitriptyline overdose

Paul T. Engels, Jonathan S. Davidow — 2010-06-02

Abstract: We report the first case of amitriptyline toxicity treated with intravenous fat emulsion (IFE). Toxicity was manifested as vasopressor-refractory haemodynamic instability despite standard therapy. Our patient recovered with no adverse effects noted.

Rapid sequence airway versus rapid sequence intubation

Viroj Wiwanitkit — 2010-05-19

I read the recent report by Southard et al. with a great interest. Southard et al. concluded that ‘In a simulated moderately difficult trauma airway managed by flight crew (FC), rapid sequence airway (RSA) results in a significantly shorter time to secure the airway and less hypoxemia compared to rapid sequence intubation (RSI)’. There are several factors to be considered before this conclusion can be generalised. First, a simulation is not real. In a stressful, real situation, the result might be totally different. Second, background knowledge of the procedure of FC is another important consideration. ‘Slow’ or ‘fast’ may depend on the practitioner's relative familiarity of the techniques. A study on the learning curve for RSA and RSI should be undertaken. Third, to get the exact information, the start time and end time of each step in each procedure should be clarified.

Reply to Letter: Rapid sequence airway vs rapid sequence intubation

Andrew Southard, Darren Braude, Cameron Crandall — 2010-05-20

We appreciate Professor Wiwanitkit's comments and interest in our recent article and would like to address some of the points raised. We completely agree that simulation cannot fully mimic a real emergency situation or true human anatomy; real world results might be very different. However, we also believe that RSA is a less technically difficult procedure, which would seemingly favor RSA over RSI in such situations. This has been borne out in the field where our air and ground EMS crews have now successfully performed over 40 actual RSA procedures. Second, the FC involved in the study were quite familiar with both procedures though most have performed more actual RSI than RSA procedures, which would again bias in favor of RSA. Third, our study considered RSI or RSA as the entire time required for the procedure from assessment of the airway to securing the airway device. This was intentionally done to better evaluate real life conditions, as all of these steps are part of airway management in the field. As each of these techniques is a “sequence,” the total accumulation of time is most important clinically.

In-flight cooling after out-of-hospital cardiac arrest

R.M. Lyon, G.M. Cowan, K.M. Janossy, J.R. Adams, A.R. Corfield, S. Hearns — 2010-05-19

Guidelines recommend cooling to 32–34°C for 12–24h in comatose survivors of out-of-hospital cardiac arrest (OHCA). Whilst the best time to start hypothermia is unknown, achieving target temperature within 4h of successful resuscitation is thought to be desirable. Aeromedical retrieval of OHCA survivors from remote locations can cause delays if hypothermia is not started during transport. Cooling equipment that is light, compact and easily stowed needs to be transported on an aircraft to enable patient cooling during transfer.

Cooling of six centigrades in an hour during avalanche burial

Gabriel Putzer, Stefan Schmid, Patrick Braun, Hermann Brugger, Peter Paal — 2010-05-19

A 28-year-old male backcountry skier was completely buried 1.5m in an avalanche when skiing down-hill. He was extricated after 90min presenting an air pocket and patent airway. On-site GCS (Glasgow Coma Score) was 5 and heart rate 120min−1; no additional parameters were measured. Extrication, first assessment without further treatment and transfer in an insulated rescue bag (Rock Snake, St. Johann, Austria) with a medical helicopter to our hospital took 25min. In the emergency room, GCS improved to 10, heart rate was 135min−1, blood pressure 170/110mmHg, and core body temperature 27.0°C measured epitympanically (Lightouch LTX, Exergen Corporation, Watertown, MA). The patient was instrumented with femorally placed arterial and central venous catheters, and monitored with ECG, invasive blood pressure measurement and pulsoxymetry; blood gas values are given in . Within 2h the patient was rewarmed to 32.6°C with warm convective air (jmk Medizintechnik e.K., Hamburg, Germany) and 2L of 42°C warm intravenous fluids. The patient was transferred to the intensive care unit. Respiratory insufficiency () was treated with continuous positive airway pressure. On the next day the patient was discharged to the normal ward; neurological, pulmonary and other organ functions were within normal range. Two days later the patient was discharged, resuming normal daily life activities.

Laryngeal mask airway training on the Advanced Life Support (ALS) Course—Is it enough?

Laurence James Hulatt — 2010-06-03

The ALS course teaches insertion of the laryngeal mask airway (LMA) using a manikin. The manual states, “to become proficient in the insertion of an LMA requires practice on patients”. However, there is no organised process to allow this to occur.

Unstable wide complex tachycardia during propafenone therapy

Chin-Feng Tsai, Sung-Kien Sia, Ming-Cheng Lin, Der-Jinn Wu, Kwo-Chang Ueng — 2010-05-20

A 70-year-old woman was admitted to our Intensive Care Unit (ICU) with the diagnosis of acute renal failure and respiratory failure. Shortly after temporal haemodialysis, she was successfully weaned from mechanical ventilator. On admission to ICU 3 days, she developed an acute atrial fibrillation episode without hemodynamic compromise. Echocardiography showed normal left ventricular ejection fraction. Amiodarone was given intravenously with resultant transition atrial fibrillation to persistent atrial flutter with 2:1 conduction and a ventricular rate of 134beats/min. She underwent attempted chemical cardioversion of atrial flutter by oral propafenone 600mg, with gradual slowing atrial flutter rate and variable atrioventricular conduction thereafter (A). Two hours after starting propafenone, she collapsed with rapid palpitation and severe hypotension (blood pressure 60/32mmHg). Twelve-lead ECG revealed a regular wide QRS tachycardia of rate 134beats/min (B). On the putative diagnosis of compromised ventricular tachycardia, immediate cardiopulmonary resuscitation with brief chest compression was applied. However, before intending to do DC cardioversion, slowing of the ventricular rate occurred spontaneously during fluid resuscitation, and acute narrowing and near normalization of the QRS complex was observed (C). Thirty minutes later, she converted spontaneously to sinus rhythm accompanied by an increased in blood pressure. The 12-lead ECG showed T wave inversion at leads V1-V3. Coronary angiography revealed left anterior descending artery spasm eliminated by intracoronary administration of isosorbide dinitrate. Thyroid function and electrolytes tests were normal. She was eventually discharged with amiodarone 200mg twice daily for preventing atrial fibrillation recurrence.

Hypercalcaemia and a Brugada-like ECG: An independent risk factor for fatal arrhythmias

2010-06-03

A 59-year-old male presented with a few weeks symptoms of anorexia, lethargy, “dizziness” and transient visual disturbance. On admission his temperature was 38°C, heart-rate 78 beats-per-minute, blood-pressure 140/90mmHg and respiratory-rate 15 breaths-per-minute. The rest of the physical examination was unremarkable. His initial blood tests showed normal haemoglobin, white-cell-count 18.1×109/L (4–11), neutrophils 14.8×109/L (2–7.5), CRP 15 (0–10), sodium (Na+) 136mmol/L (134–145mmol/L), potassium (K+) 3.5mmol/L (3.5–5.3mmol/L), urea 20.4mmol/L (2.0–6.5mmol/L), creatinine 205μmol/L (70–120μmol/L), and corrected-calcium 4.45mmol/L (2.2–2.6mmol/L). His 12-lead ECG demonstrated Brugada-syndrome (BrS) like appearance, showing sinus-rhythm, RBBB-pattern with ST-segment elevation and T-wave inversion in V1–V3, QTc 447ms (A).

Takotsubo cardiomyopathy related to carbamate and pyrethroid intoxication

Chi-Cheng Lin, Shih-Yuan Lai, Sung-Yuan Hu, Yu-Tse Tsan, Wei-Hsiung Hu — 2010-06-03

Transient left ventricular apical ballooning, known in Japan as takotsubo cardiomyopathy, mimics myocardial infarction but is not associated with a critical lesion on coronary arteriography. Exposure to carbamates and pyrethroids may lead to cardiovascular toxicities; however, apical ballooning syndrome induced by insecticide has never been reported. We present a case of insecticide-induced takotsubo cardiomyopathy, which was proven by echocardiogram and coronary arteriogram.

Are paediatric residents able to deliver basic CPR procedures? Ventilation and chest compression rate

2010-06-03

Quality of cardiopulmonary resuscitation (CPR) is an important determinant of outcome. However, several studies have shown that the quality of CPR is suboptimal, even when performed by experienced health staff. The most common errors are hyperventilation and inadequate chest compressions. Paediatric residents should be trained to perform CPR manoeuvres effectively and they should maintain such skills by means of retraining programs and real patient resuscitations. Our objective was to assess if paediatric residents are able to ventilate with bag and mask and to deliver chest compressions according to current guidelines.

Simulation training for cardiac arrest in children: Is there an interest for general emergency medical system?

2010-06-04

New guidelines for the management of cardiac arrest in children and infants were published in 2005 by the International Liaison Committee On Resuscitation and the European Resuscitation Council. These guidelines preceded publication of French recommendations in September 2006, including changing practices in Paediatric Life Support (PLS).

Hospital doctors’ knowledge of adrenaline (epinephrine) administration in anaphylaxis in adults is deficient

Jan Droste, Nithin Narayan — 2010-06-03

Recently a critical incident occurred in a NHS trust in the North of England. A junior doctor was instructed by his consultant to administer 1mg of adrenaline/epinephrine intravenously, to an alert and not haemodynamically compromised 45-year-old patient with anaphylaxis (due to receiving an intravenous antibiotic). The patient suffered from transient coronary vasospasm with a subsequent troponin rise, attributed to the intravenous adrenaline.

Crewdson Kate — 2010-05-19

Rapid Sequence Intubation & Rapid Sequence Airway is the second edition of a book written by an Emergency Physician based in the United States, who originally trained as a paramedic. It is aimed at a wide audience including paramedics, nurses, doctors and aeromedical crews. The book is easy to read, although the content is rather jumbled. All aspects of rapid sequence intubation (RSI) are covered. A coding system is used throughout the book to draw the reader's attention to sections of text that reflect either evidence-based medicine, a ‘caution’ for potential pitfalls, or important points identified by the author. The idea behind such a coding system is commendable; however, the referencing system within the book is unclear. It is not possible to identify which example of evidence-based medicine comes from which paper. The references for each chapter are listed at the back of the book but are not numbered correspondingly within the text. The usefulness of some references is questionable, for example, describing trismus as a side effect of suxamethonium – this appears to be based on scanty evidence from case reviews.

James Walters — 2010-06-03

This practical guide to drugs in intensive care was first published in 2000 and is now in its fourth edition. It is divided into two main sections plus several useful appendices and includes an extremely helpful drug compatibility chart.