Pupillary Response to Light is Preserved in Patients without Brain Insult Undergoing Rapid Sequence Intubation

Objective of the Study: This paper has been aimed to determine whether the pharmacological neuromuscular blockade with rocuronium during emergency Rapid Sequence Intubation (RSI) affected pupillary response to light (PLR) in patients with brain insult as compared to patients who had non- neurological illness. Previous studies elucidated that RSI with pharmacological neuromuscular blockade does not affect PLR, except in patients with significant neurological lesion. Our objective is to examine the validity of existing but scarce literature on this subject, with further stratification of patients involved in this study into neurological and non-neurological disease groups.

Methods: This was a prospective case-reference study of case group with brain insult patients compared with reference group of patients without neurological diseases undergoing RSI in emergency settings. It is single centered study, conducted from October 2019 till May 2020. A pair of a neurosurgeon and a medical officer assessed pupillary light response after administration of neuromuscular blockade and intubation, each blinded to other’s assessment of PLR. Cases without pupillary response before RSI intubation were excluded. The primary outcome measure was clinically observable Pupillary Light Response (PLR) following neuromuscular blockade with Rocuronium in each group.

Results: We examined 50 patients undergoing RSI with Rocuronium, either in emergency department or Intensive Care Unit (ICU), 25 each in index and reference group respectively. All patients in the reference group showed PLR after RSI. Of case group patients receiving RSI, only15 of 25 (60%) demonstrated PLR after RSI. This was statistically significant (p value<0.05) when compared to number of patients with intact PLR after RSI in reference group. Cohen’s Kappa Coefficient (k) for inter-observer agreement was 0.70.

Conclusion: Rocuronium does not appear to affect PLR after emergent RSI in patients without brain injury. Only in patients with known brain insult showed impaired PLR, suggesting impaired pupillary light reflex mechanism may be the culprit for this aberration, rather than pharmacological neuromuscular blockade.