Infrared pupillometry to detect the light reflex during cardiopulmonary resuscitation: a case series

Abstract

Background: The presence or absence of the pupillary light reflex following cardiopulmonary resuscitation has been shown to have prognostic value. We asked whether the light reflex could be objectively measured during cardiopulmonary resuscitation in humans and whether the quality of the reflex was associated with outcome.

Methods: Sixty-seven in-hospital code blue alerts were attended of which 30 met our inclusion criteria. Portable infrared pupillometry was used to measure the light reflex during each code. The reliability of the presence of the light reflex during each code as a predictor of survival and neurological outcome was analyzed statistically using the Barnard's Exact test.

Results: In 25 patients (83%) the pupillary light reflex was detectable throughout or during a part of the resuscitation. Continuous presence of the light reflex or absence for less than 5 min during resuscitation was associated with early survival of the code and a good neurological outcome. In contrast, no patients without a light reflex or with a gradually deteriorating light reflex survived the code and absence of a pupillary light reflex for more than 5 min was associated with an unfavorable outcome.

Conclusion: Portable infrared pupillary measurements can reliably demonstrate the presence and quality of the pupillary light reflex after cardiac arrest and during resuscitation. In our limited case series, the presence of the pupillary light reflexes obtained in serial measurements during resuscitation was associated with early survival and a favorable neurological status in the recovery period.