Prevalence and Predictors of Post-Intubation Hypotension in Prehospital Trauma Care

Prehospital care of severe trauma patients often involves endotracheal intubation (ETI), which has complications. The frequency and predictors of post-ETI hypotension and cardiac arrest are not well defined in this population. We sought to derive and validate a scoring system that predicts post-ETI hypotension in prehospital patients and to describe the impact of hypotension on outcome. We performed an observational cohort study including normotensive adult trauma patients requiring ETI, treated from 2001 to 2018 by critical care transport providers in a regional air medical transport system. We divided eligible patients into a derivation cohort (2001-2010) and validation cohort (2011-2018) for analysis. We identified predictors of new systolic hypotension (<90 mmHg) or cardiac arrest within 15 minutes of ETI then developed and validated a scoring system that stratified patients into low, moderate and high risk. We included 4,866 subjects, 3,127 in the derivation and 1,739 in the validation cohort. Post-ETI hypotension occurred in 11% and 21%, respectively; 5% of each cohort experienced post-ETI cardiac arrest. Major independent predictors of post-ETI hypotension were age, pre-ETI systolic blood pressure and pre-ETI oxygen saturation. We developed a well-calibrated scoring system based on these major and several minor risk factors. Applying our system, 890 (33%) derivation patients and 550 (37%) validation patients were higher risk for post-ETI adverse outcomes. Of these, 21% and 33% respectively experienced post-ETI hypotension and 6% and 4%, respectively suffered post-ETI cardiac arrest. Patients at high risk for post-ETI hypotension or arrest are common and identifiable in prehospital trauma care.