What Happens to Spo₂ During Air Medical Crew Intubations?

Abstract

Objectives. Studies finding adverse outcomes associated with emergency medical services intubation (ETI) have prompted recommendations for prehospital services to improve tracking of oxygenation during airway management. Our goals were to 1) implement a documentation requirement for helicopter EMS (HEMS) crews, entailing tracking andnotation of the lowest SpO₂ value (peri-ETI SpO₂ nadir) occurring during HEMS crew ETI, and2) assess the findings associated with the peri-ETI SpO₂ documentation parameter. Methods. This was a prospective study conducted at an urban HEMS program with flight nurse/flight paramedic staffing andprotocol-driven care. There were 200 consecutive cases undergoing HEMS ETI between April 2004 andJuly 2005. Univariate logistic regression with odds ratio (OR) was used to assess for association between ETI-related hypoxemia (decrease in SpO₂ value to < 90% during ETI) andpatient/intubator characteristics. Results. HEMS crew ETI was successful in 189 (95.4%) of the 200 patients. The lowest peri-ETI SpO₂ value was specifically documented in 170 patients (85%) in the study group. In univariate analysis, successful crew ETI was correlated with avoidance of crew-recorded SpO₂ value decreasing to < 90% (OR, 0.23; 95% confidence interval, 0.07–0.83). Similarly, requirement for multiple attempts at ETI was correlated with higher likelihood that crews recorded peri-ETI SpO₂ value decreasing to < 90% (OR, 7.8; 95% confidence interval, 3.2–18.8). However, in nearly two thirds of cases in which multiple attempts were executed, the peri-ETI SpO₂ value remained > 90%. Of the seven patients in whom rescue laryngeal mask airways were placed, the peri-ETI SpO₂ value remained > 90% in three (42.9%). Conclusion. Documentation of crew-recorded peri-ETI SpO₂ nadir is a useful andpractical prehospital data point.

Key words:

• prehospital
• EMS
• air transport
• SpO₂ monitoring.