UMEM Educational Pearls

Several studies have described factors associated with peri-intubation cardiac arrest in the adult population. Factors such as pre-intubation hypotension, elevated BMI, and elevated shock index (HR/SBP) have been associated with cardiac arrest following intubation in adult ED patients. Given the differences in anatomy and physiology in children, one may expect risk factors for peri-intubation cardiac arrest to differ in children.

A number of studies have examined factors associated with peri-intubation cardiac arrest in the pediatric population, but these have remained limited to the inpatient setting. These studies have found that, in hospitalized and PICU patients, the factors of hemodynamic instability, hypoxemia, history of difficult airway, pre-existing cardiac disease, and higher number of intubation attempts are associated with peri-intubation cardiac arrest. A paucity of literature exists on this airway complication in pediatric ED patients.

Pokrajac et al. provide the first study on risk factors for peri-intubation cardiac arrest in pediatric ED patients. These authors conducted a retrospective nested case-control study of pediatric patients (ages <18 years) who presented to a tertiary children’s hospital in San Diego from 2009-2017. Cases included patients who had a cardiac arrest within 20 minutes after the start of endotracheal intubation. Authors selected a number of predictors to examine, including age-adjusted hemodynamic variables, capillary refill, pulse oximetry, patient characteristics, intubation-related factors, and pre-intubation interventions.

The authors found the following:

-       Demographic characteristics:

o   Patients with peri-intubation cardiac arrest were significantly younger (<1 year of age), shorter, and more likely to have history of preexisting pulmonary disease.

-       Incident characteristics:

o   Patients with peri-intubation cardiac arrest were more likely to have:

       -Low or unobtainable SBP or DBP

       -Delayed capillary refill time

       -Low (<92%) or unobtainable pre-intubation SpO2

        -More than 1 intubation attempt than controls

        -No paralytic or sedative agent prior to intubation

o   Patients with peri-intubation cardiac arrest were NOT more likely to have increases in age-adjusted HR or pediatric shock index in comparison to controls.

o   The strongest clinical predictor for peri-intubation cardiac arrest was pre-intubation hypoxia or unobtainable SpO2. This fact is supported by children’s increased metabolic rate and thus increased oxygen consumption. This physiologic finding explains the shorter amount of time it takes children to develop acute hypoxia, particularly in the peri-intubation setting.

Bottom line: If planning to intubate a pediatric patient in the ED, keep in mind that pre-intubation systolic or diastolic hypotension, delayed capillary refill time, multiple intubation attempts, and hypoxia in particular may increase the risk for peri-intubation cardiac arrest. Consider providing apneic oxygenation to minimize hypoxemia prior to intubation.

References

Heffner, A. C., Swords, D. S., Neale, M. N. & Jones, A. E. Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation 84, 1500–1504 (2013).

Hill, K. Cardiac Arrests Associated with Tracheal Intubations in PICUs: A Multicenter Cohort Study. The Journal of Emergency Medicine 51, 617–618 (2016).

Kim, W. Y. et al. Factors Associated with the Occurrence of Cardiac Arrest after Emergency Tracheal Intubation in the Emergency Department. PLoS ONE 9, e112779 (2014).

Pokrajac, N. et al. Risk Factors for Peri-intubation Cardiac Arrest in a Pediatric Emergency Department Pediatric Emergency Care Publish Ahead of Print, (2020).