Abstract
Background
Respiratory critical care guidelines suggest heating the air/oxygen mixture but do
not recommend a specific temperature target. We aimed to clarify if the inspired gas
temperature influences lung mechanics and gas exchange in intubated patients treated
with whole body hypothermia (WBH) or normothermia (NT).
Methods
Prospective cohort study enrolling neonates ventilated for perinatal asphyxia resuscitation
(no lung disease) or acute hypoxemic respiratory failure. Patients were divided between
those ventilated in NT or WBH. Compliance (Cdyn), airway resistances (Raw), oxygenation index (OI), PaO2/FiO2, A-a gradient, a/A ratio, estimated alveolar dead space (VDalv), ventilatory index (VI) and CO2 production (VCO2) were registered at the study beginning (inspired gas at 37°C). Then, gas temperature
was decreased (32 °C) and variables were recorded again after 1 and 3 h. Data were
analysed with univariate and multivariate repeated measures-ANOVA.
Results
Cdyn, Raw, OI, PaO2/FiO2, A-a gradient, a/A ratio, VDalv, VI and VCO2 are similar between WBH and NT at any timepoint (between-subjects effect); these
results do not change adjusting for the presence of respiratory failure. When this
is considered in multivariate ANOVA (within-subjects effect), Cdyn (p = 0.016), Raw (p = 0.034) and VDalv (p < 0.001) were worse in patients with respiratory failure than in those without lung
disease.
Conclusions
Decreasing the gas temperature from 37 °C to 32 °C for 3 h does not change lung mechanics
and gas exchange, neither in neonates with, nor in those without respiratory failure
and in those treated in NT or WBH. These findings fill a knowledge gap regarding the
effect of inspired gas temperature during WBH: they may inform future respiratory
critical care guidelines.
Keywords
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References
- ILCOR ALS Task Force. Temperature management after cardiac arrest: an advisory statement by the advanced life support task force of the International Liaison Committee on Resuscitation and the American Heart Association Emergency Cardiovascular Care Committee and the Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation.Resuscitation. 2016; 98: 97-104
- European Resuscitation Council and European Society of Intensive Care Medicine 2015 guidelines for post-resuscitation care.Intensive Care Med. 2015; 41: 2039-2056
- Committee on fetus and newborn. Hypothermia and neonatal encephalopathy.Pediatrics. 2014; 133: 1146-1150
- Body temperature effects on lung injury in ventilated preterm lambs.Resuscitation. 2010; 81: 749-754
- Controlled hypothermia may improve surfactant function in asphyxiated neonates with or without meconium aspiration syndrome.PLoS One. 2018; 13: e0192295https://doi.org/10.1371/journal.pone.0192295
- Molecular and biophysical mechanisms behind the enhancement of lung surfactant function during controlled therapeutic hypothermia.Sci Rep. 2021; 11: 728https://doi.org/10.1038/s41598-020-79025-3
- Effect of whole body hypothermia on inflammation and surfactant function in asphyxiated neonates.Eur Respir J. 2014; 44: 1708-1710
- Induced hypothermia as a new approach to lung rest for the acutely injured lung.Crit Care Med. 2005; 33: 2049-2055
- Moderate hypothermia attenuates oxidative stress injuries in alveolar epithelial A549 cells.Exp Lung Res. 2013; 39: 217-228
- Effect of cooling on lung secretory phospholipase A2 activity in vitro, ex vivo, and in vivo.Am J Physiol Lung Cell Mol Physiol. 2019; 316: L498-L505
- Use of hypothermia to allow low-tidal-volume ventilation in a patient with ARDS.Respir Care. 2011; 56: 1956-1958
- Induced hypothermia for trauma-related ARDS.Indian J Crit Care Med. 2015; 19: 353-355
- Rescue hypothermia for refractory hypercapnia.Eur J Pediatr. 2012; 171: 1855-1857
- Effect of whole body hypothermia on surfactant function when amniotic fluid is meconium stained.Ther Hypothermia Temp Manage. 2017; 10: 186-189
- Bile acids cause secretory phospholipase A2 activity enhancement, revertible by exogenous surfactant administration.Intensive Care Med. 2009; 35: 321-326
- Role of distinct phospholipases A2 and their modulators in meconium aspiration syndrome in human neonates.Intensive Care Med. 2011; 37: 1158-1165
- Hypothermia and Meconium Aspiration Syndrome: International Multicenter Retrospective Cohort Study.Am J Respir Crit Care Med. 2016; 194: 381-384
- Humidification During Invasive and Noninvasive Mechanical Ventilation: 2012.Respir Care. 2012; 57: 782-788
- Under-humidification and over-humidification during moderate induced hypothermia with usual devices.Intensive Care Med. 2006; 32: 1014-1021
- Use of normothermic default humidifier settings causes excessive humidification of respiratory gases during therapeutic hypothermia.Ther Hypothermia Temp Manage. 2016; 6: 180-188
- Cell count analysis from nonbronchoscopic bronchoalveolar lavage in preterm infants.J Pediatr. 2018; 200 (e2): 30-37
- Moderate hypothermia to treat perinatal asphyxial encephalopathy.N Engl J Med. 2009; 361: 1349-1358
- Estimation of early life endogenous surfactant pool and CPAP failure in preterm neonates with RDS.Respir Res. 2019; 20: 75https://doi.org/10.1186/s12931-019-1040-z
- The Montreux definition of neonatal ARDS: biological and clinical background behind the description of a new entity.Lancet Respir Med. 2017; 5: 657-666
- Secretory phospholipase A2 and neonatal respiratory distress: pilot study on broncho-alveolar lavage.Intensive Care Med. 2008; 34: 1858-1864
https://techweb.stryker.com/Gaymar/TMP/Medi-Term/MTA6900/100974000.pdf, n.d. [accessed 07.02.21].
- Respiratory gas conditioning in infants with an artificial airway.Semin Neonatol. 2002; 7: 369-377
ISO 8185:2007. Respiratory tract humidifiers for medical use. Particular requirements for respiratory humidification systems, 2007. Available at: www.iso.org/iso/iso_catalogue/catalogue_?csnumber=tc/catalogue_detail.htm=38527; n.d. [accessed 07.02.21].
https://resources.fphcare.com/content/mr850-respiratory-humidifier-user-instructions-ui-185042343.pdf; n.d. [accessed 07.02.21].
- Technical problems with dynamic compliance evaluation in neonates and infants.Intensive Care Med. 2012; 38: 1082-1083
- Estimating alveolar dead space from the arterial to end-tidal CO2 gradient: a modeling analysis.Anesth Analg. 2003; 97: 1846-1851
- Cardiorespiratory and metabolic effects of profound hypothermia.Crit Care Med. 1978; 6: 340-346
- Blood gas values during hypothermia in asphyxiated term neonates.Pediatrics. 2009; 123: 170-172
- Dynamic respiratory system mechanics in infants during pressure and volume controlled ventilation.Eur Respir J. 2001; 17: 115-121
- Impact of endotracheal tube biofilm and respiratory secretions on airway resistance and mechanics of breathing in a neonatal lung model.J Appl Physiol. 2018; 125: 1227-1231
- Cooling techniques for targeted temperature management post-cardiac arrest.Crit Care. 2015; 19: 103https://doi.org/10.1186/s13054-015-0804-1
- Perioperative effects of alpha-stat versus pH-stat strategies for deep hypothermic cardiopulmonary bypass in infants.J Thorac Cardiovasc Surg. 1997; 114: 991-1001
- Monitoring gas exchange during hypothermia for hypoxic-ischemic encephalopathy.Pediatr Crit Care Med. 2019; 20: 166-171
- Alpha-stat acid-base regulation during cardiopulmonary bypass improves neuropsychologic outcome in patients undergoing coronary artery bypass grafting.J Thorac Cardiovasc Surg. 1996; 111: 1267-1279
Article info
Publication history
Published online: April 22, 2021
Accepted:
April 12,
2021
Received in revised form:
March 27,
2021
Received:
February 6,
2021
Identification
Copyright
© 2021 Elsevier B.V. All rights reserved.
