P2B035: Reducing Risk in the Physiologically Difficult Pediatric Airway: A Secondary Analysis of a Multicenter, Observational Study

Background: Cardiac arrest is the most feared adverse event during tracheal intubation, and pediatric patients who meet high risk criteria for the physiologically difficult airway are especially at risk. Little is known about strategies to mitigate this risk. The objective of this study was to determine if pre-intubation interventions designed to optimize the physiologic status of high-risk pediatric patients are associated with a reduced risk of peri-intubation arrest.

Methods: We conducted a secondary analysis of a multicenter, observational, retrospective cohort study of intubations in eight US pediatric emergency departments. Inclusion criteria were patients less than 21 years old who underwent rapid sequence intubation (i.e., non-crash) and met at least one of six previously identified high-risk criteria for peri-intubation arrest (persistent hypoxemia despite supplemental oxygen, persistent hypotension, concern for cardiac dysfunction, post-return of spontaneous circulation, severe metabolic acidosis, and status asthmaticus). We compared patients that received pre-intubation interventions designed to optimize physiologic status (intravenous fluids, vasoactive medications, and sodium bicarbonate) to patients that did not receive these interventions. Our primary outcome was peri-intubation cardiac arrest. Secondary outcomes included hypotension, hypoxia, and in-hospital mortality. We performed unadjusted and adjusted analyses, evaluating for an association between exposures and outcomes of interest.

Results: Each of the eight sites reviewed their 150 most recent intubations that met inclusion criteria, resulting in 1200 pediatric intubations. There were 332 patients that met at least one high-risk criterion. Of these, 264 (79.5%) received at least one pre-intubation intervention (257 [77.4%] patients received IVF, 87 [26.2%] received vasoactive medications, and 20 [6%] received sodium bicarbonate). For unadjusted and adjusted analyses, there was no significant difference in peri-intubation cardiac arrest between patients that received no pre-intubation interventions and those that received at least one. However, when analyzed by number of pre-intubation interventions received, there was an increased rate of peri-intubation cardiac arrest as patients received additional pre-intubation interventions. In general, the rates of hypoxia, hypotension and in-hospital mortality also increased as patients received additional pre-intubation interventions.

Conclusion: To our knowledge, this is the first study to evaluate for an association between pre-intubation interventions and peri-intubation cardiac arrest in high-risk pediatric intubations. In general, pre-intubation interventions were not associated with peri-intubation cardiac arrest, though our data suggest that patients that received multiple additional interventions were at increased risk. Based on our experience, we do not believe our data suggest that pre-intubation interventions are causing harm and instead believe that not all high-risk patients are created equal. Physiologically difficult airways are nuanced and complex clinical cases, representing a large variety of physiologic derangements. These high-risk patients can likely be further risk stratified beyond current risk-stratification systems. We believe further multicenter, prospective video-review based studies are warranted to help understand which patients are at the highest risk.