In emergently ventilated trauma patients, low end-tidal CO2 and low cardiac output are associated and correlate with hemodynamic instability, hemorrhage, abnormal pupils, and death

摘要

Background In a smaller experience, the authors previously demonstrated that end-tidal carbon dioxide (PetCO₂) and cardiac output (CO) had a positive association in emergently intubated trauma patients during Emergency Department resuscitation. The aim of this larger study was to reassess the relationship of PetCO₂ with CO and identify patient risk-conditions influencing PetCO₂ and CO values. Methods The investigation consists of acutely injured trauma patients requiring emergency tracheal intubation. The study focuses on the prospective collection of PetCO₂ and noninvasive CO monitor (NICOM?) values in the Emergency Department. Results From the end of March through August 2011, 73 patients had 318 pairs of PetCO₂ (mm Hg) and CO (L/min.) values. Mean data included Injury Severity Score (ISS) ≥15 in 65.2%, Glasgow Coma Score of 6.4?±?4.6, hypotension in 19.0%, and death in 34.3%. With PetCO₂?≤?25 (15.9?±?8.0), systolic blood pressure was 77.0?±?69, CO was 3.2?±?3.0, cardiac arrest was 60.4%, and mortality was 84.9%. During hypotension, CO was lower with major blood loss (1.9), than without major loss (5.0; P?=?0.0008). Low PetCO₂ was associated with low CO (P?2 was associated (P?≤?0.0012) with ISS?>?20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Low CO was associated (P?≤?0.0059) with ISS?>?20, hypotension, bradycardia, major blood loss, abnormal pupils, cardiac arrest, and death. Conclusions During emergency department resuscitation, a decline in PetCO₂ correlates with decreases in noninvasive CO in emergently intubated trauma patients. Decreasing PetCO₂ and declining NICOM CO are associated with hemodynamic instability, hemorrhage, abnormal pupils, and death. The study indicates that NICOM CO values are clinically discriminate and have physiologic validity.