Characteristics of a Brisk or Sluggish Pupillary Light Reflex: A Nursing Perspective

Pupillary light reflex (PLR) has traditionally been assessed using a pen torch (light). Although the terms "brisk" or "sluggish" are often used, it is unclear what characteristics of the PLR result in this description. More recently, automated infrared pupillometry has enabled us to quantify the different components of a PLR.

We conducted a 2-part questionnaire survey of pediatric intensive care unit (PICU) nurses. In part 1, nurses were requested to describe the key characteristics that they associate with a brisk or sluggish PLR in free-text responses. In part 2, after an introduction to pupillometry and the different components of a PLR, nurses were asked to rank the relative importance of latency (time taken for pupil to start reacting to light), percentage change (in pupil size after light stimulus), and constriction velocity (rate of constriction after light stimulus) in relation to a pupil being described as "brisk" and "sluggish.

Fifty nurses responded. In part 1, "Quick" was the commonest term used (36% of respondents) to describe a brisk PLR, and 72% used "slow" for a sluggish PLR. Most descriptions most closely mapped to features of latency and/or constriction velocity. In part 2, latency was ranked the most important component on pupillometry for describing brisk (32%) and sluggish (34%) PLRs. Constriction velocity was ranked as the most important by 18% (brisk) and 20% (sluggish), whereas 44% (brisk) and 46% (sluggish) ranked percentage change behind the other 2 characteristics.

Latency, followed by the constriction velocity, was felt by PICU nurses to be the most important characteristic of the PLR that results in terms "brisk" or "sluggish" being used at the bedside to describe a PLR. We plan to compare these subjective opinions with objective findings from pupillometry.