Incidence of transient hypoxia and pulse rate reactivity during paramedic rapid sequence intubation

Study objective: We determine the incidence of desaturation and pulse rate reactivity during paramedic rapid sequence intubation of patients with severe head injuries (Glasgow Coma Scale score less than or equal to58). Methods: Adult patients with severe head injuries had recording oximeter-capnometers applied before rapid sequence intubation. Desaturation was defined as a reduction in oxygen saturation (Sp(O2)) to less than 90% from an initial Sp(O2) of greater than or equal to 90% or a decrease from a baseline of less than 90%. Event records were analyzed with emergency medical services (EMS) run sheets and debriefing reports. Results: Thirty-one (57%) of 54 patients demonstrated desaturation during rapid sequence intubation. Twenty-six (84%) of these 31 events occurred in patients whose initial Sp(O2) value with basic airway skills was greater than or equal to 90%. The median duration of desaturation was 160 seconds (interquartile range 48 to 272 seconds), and the median decrease in Sp(O2) was 22%. Six (19%) patients experienced marked bradycardia (pulse rate <50 beats/min) during desaturation events. Paramedics described rapid sequence intubation as "easy" in 26 (84%) of 31 patients with desaturation. Conclusion: Out-of-hospital rapid sequence intubation by paramedics was complicated by a concerning incidence of desaturation and bradycardia. Paramedic reports did not reflect the presence of these concerning derangements. Most patients had acceptable Sp(O2) values before rapid sequence intubation. An effective strategy for preoxygenation is needed before it can be concluded that rapid sequence intubation is of value in the out-of-hospital care of patients with serious closed head injury.