CHEST Guidelines-Quantitative-Pupillometry

Quantitative-Pupillometry_chest

Pdf Summary

Quantitative pupillometry, an objective method to measure pupil size and reactivity using a portable device, has emerged as a reliable tool in clinical assessments, especially in intensive care units (ICUs). It provides quantitative metrics of pupil size and constriction speed in response to light, known as the pupillary light reflex (PLR), which is more reliable than subjective assessments. Recent studies have highlighted its potential as a prognostic tool in predicting outcomes for comatose patients, particularly those with hypoxic ischemic injury following cardiac arrest or refractory cardiogenic shock who are undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO).<br /><br />In 2017, research showed that a quantitative PLR of 13% had 100% specificity and positive predictive value for identifying patients with poor recovery post-cardiac arrest. Building on this, Miroz and colleagues conducted an observational study involving 100 patients undergoing VA-ECMO. They used the Neurologic Pupil Index (NPi) to evaluate pupil reactivity between 24 and 72 hours post-VA-ECMO insertion, finding that an NPi ≤3 was 100% specific for predicting 90-day mortality. Incorporating NPi with the 12-hour PREDICT VA-ECMO score enhanced the sensitivity of mortality prediction.<br /><br />While the study's strengths include a relatively large sample size and consistent assessments, limitations such as the influence of pharmacologic agents on NPi and potential data availability to clinicians may impact interpretability. Nonetheless, the research supports the utility of quantitative pupillometry as a prognostic tool in critically ill patients, emphasizing the importance of not performing prognostic assessments too early, aligning with current US and European guidelines. Understanding how to apply this tool can optimize patient care by informing family expectations and guiding clinical decision-making in resource allocation.

Keywords

quantitative pupillometry

pupillary light reflex

intensive care units

prognostic tool

cardiac arrest

venoarterial extracorporeal membrane oxygenation

Neurologic Pupil Index

mortality prediction

clinical assessments

hypoxic ischemic injury