Inadvertent Hypothermia After Procedural Sedation and Analgesia in a Cardiac Catheterization Laboratory: A Prospective Observational Study

ObjectivesTo identify the prevalence of and risk factors for inadvertent hypothermia after procedures performed with procedural sedation and analgesia in a cardiac catheterization laboratory.DesignA single-center, prospective observational study.SettingA tertiary-care private hospital in Australia.Participants399 patients undergoing elective procedures with procedural sedation and analgesia were included. Propofol infusions were used when an anesthesiologist was present. Otherwise, bolus doses of either midazolam or fentanyl or a combination of these medications was used.InterventionsNoneMeasurements and Main ResultsHypothermia was defined as a temperature<36.0°C. Multivariate logistic regression was used to identify risk factors. Hypothermia was present after 23.3% (n = 93; 95% confidence interval [CI] 19.2%-27.4%) of 399 procedures. Sedative regimens with the highest prevalence of hypothermia were any regimen that included propofol (n = 35; 40.2%; 95% CI 29.9%-50.5%) and the use of fentanyl combined with midazolam (n = 23; 20.3%; 95% CI 12.9%-27.7%). Difference in mean temperature from pre-procedure to post-procedure was –0.27°C (standard deviation 0.45). Receiving propofol (odds ratio [OR] 4.6 95% CI 2.5-8.6), percutaneous coronary intervention (OR 3.2; 95% CI 1.7-5.9), body mass index<25 (OR 2.5; 95% CI 1.4-4.4) and being hypothermic prior to the procedure (OR 4.9; 95% CI 2.3-10.8) were independent predictors of post-procedural hypothermia.ConclusionsA moderate prevalence of hypothermia was observed. The small absolute change in temperature observed may not be a clinically important amount. More research is needed to increase confidence in the authors’ estimates of hypothermia in sedated patients and its impact on clinical outcomes.