Should capnography be used as a guide for choosing a ventilation strategy in circulatory shock caused by severe hypothermia? Observational case-series study. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Darocha, Tomasz; Kosiński, Sylweriusz; Jarosz, Anna; Podsiadło, Paweł; Ziętkiewicz, Mirosław; Sanak, Tomasz; Gałązkowski, Robert; Piątek, Jacek; Konstanty-Kalandyk, Janusz; Drwiła, Rafał
• Is Part Of: Scandinavian journal of trauma, resuscitation and emergency medicine. Volume 25:Issue 1(2017)
• Page Start: 1
• Page End: 4
• Publication Date: 2017-12
• Subjects: Accidental hypothermia -- Pulmonary ventilation -- Capnography; Emergency medicine -- Periodicals; Wounds and injuries -- Periodicals; 616.02505
• DOI: 10.1186/s13049-017-0357-1
• Languages: English
• ISSNs: 1757-7241

Abstract

Abstract Background Severe accidental hypothermia can cause circulatory disturbances ranging from cardiac arrhythmias through circulatory shock to cardiac arrest. Severity of shock, pulmonary hypoperfusion and ventilation-perfusion mismatch are reflected by a discrepancy between measurements of CO2 levels in end-tidal air (EtCO2 ) and partial CO2 pressure in arterial blood (PaCO2 ). This disparity can pose a problem in the choice of an optimal ventilation strategy for accidental hypothermia victims, particularly in the prehospital period. We hypothesized that in severely hypothermic patients capnometry should not be used as a reliable guide to choose optimal ventilatory parameters. Methods We undertook a pilot, observational case-series study, in which we included all consecutive patients admitted to the Severe Hypothermia Treatment Centre in Cracow, Poland for VA-ECMO in stage III hypothermia and with signs of circulatory shock. We performed serial measurements of arterial blood gases and EtCO2, core temperature, and calculated a PaCO2 /EtCO2 quotient. Results The study population consisted of 13 consecutive patients (ten males, three females, median 60 years old). The core temperature measured in esophagus was 20.7–29.0 °C, median 25.7 °C. In extreme cases we have observed a Pa-EtCO2 gradient of 35–36 mmHg. Median PaCO2 /EtCO2 quotient was 2.15. Discussion and Conclusion Severe hypothermia seems to present an example of extremely large Pa-EtCO2 gradient. EtCO2 monitoring does not seem to be a reliable guide to ventilation parameters in severe hypothermia.