Elsevier

Journal of Critical Care

Volume 29, Issue 4, August 2014, Pages 599-603
Journal of Critical Care

Monitoring/Outcomes
Automated pupillometer for monitoring the critically ill patient: A critical appraisal

https://doi.org/10.1016/j.jcrc.2014.01.012Get rights and content

Abstract

Abnormalities in the pupillary light reflex are an important prognostic indicator for patients in the intensive care unit (ICU). Manual pupillary examination is confounded by interobserver discrepancies and errors in detecting a reflex under certain conditions. The automated pupillometer is a computer-based infrared digital video device that can obtain objective measurements of pupillary size and reactivity. We performed an electronic literature search to identify original studies on the use of the automated pupillometer in the ICU. We identified 7 articles that met the inclusion criteria and reviewed them critically and assessed the quality of evidence by using the Grading of Recommendations Assessment, Development, and Evaluation approach. We found that the study grade was low, and study quality was low to moderate for all the reviewed manuscripts. Pupillometric measurements had better precision and reproducibility compared with the manual pupillary examination. Based on these data, we conclude that pupillometry monitoring can serve as an important tool in the ICU. Further large scale studies on patients in the neurocritical care unit and medical ICU are needed to support the routine use of automated pupillometry.

Introduction

The pupillary light reflex is a commonly used prognostic indicator in the neurocritical care unit (neuroICU), general intensive care unit (ICU), and coma patients. Changes in the pupillary size and reactivity can provide important clues to neurologic deterioration, elevated intracranial pressure (ICP), and herniation [1]. In a study of functional recovery in patients with traumatic transtentorial herniation, only 3.5% of patients with bilaterally fixed and dilated pupils at admission had a functional recovery [2]. The combination of the pupillary examination and Glasgow Coma Scale (GCS) score provides more accurate prognostic information, and patients with a GCS of 3 with reactive pupils have a 33% survival rate, as opposed to patients with a GCS of 3 and fixed dilated pupils who have no reasonable chance of recovery [3]. Therefore, early and accurate detection of pupillary changes can decrease time to appropriate interventions and avoid frequent computed tomographic scans. In addition, accurate pupillary examination can help detect transtentorial herniation in some head injury patients with low speed trauma who undergo early herniation [4]. The current most commonly used methodology to assess pupillary function is bedside manual light reflex performed by clinicians and nurses. However, the manual pupillary examination is limited by interobserver differences and errors in detecting a light reflex in very small and dilated pupils [5], [6], [7]. The automated pupillometer is a computer-based infrared digital video device than can be used to obtain objective measurements of pupillary size, reactivity, and asymmetry rapidly and with ease under controlled light stimuli. In this article, we review the literature available on the application of the automated pupillometer in the ICU and assess the practicality of using routine automated pupillometry on all neuroICU and ICU patients.

Section snippets

Methods

We undertook a Pubmed literature search on automated pupillometry in the ICU, using the key word “pupillometry” and at least one of the following terms or phrases: “neurocritical care,” “intracranial pathology,” “neurological monitoring,” “intracranial pressure,” “herniation,” “head trauma,” “intensive care,” “critical care,” “intracranial lesions,” “critically ill patients,” “outcomes,” “prognosis.” We included manuscripts that reported on original studies with human subjects. We then

Results

We selected and reviewed 7 manuscripts. We found that all the studies published were prospective case reviews and observational case series and case reports and 1 small randomized study. The grading of all studies was low, and the overall quality of evidence was low to moderate. Based on these results, the automated pupillometer can be a valuable tool in the neuroICU. However, further studies are needed to assess the practicality of its widespread and routine use. Table 1 summarizes the studies

Discussion and summary of literature

The automated pupillometer can be used to provide an objective measure of pupillary size and reactivity. The automated pupillometer has a color LCD, a digital camera, and an intrinsic source of illumination. It uses infrared light to illuminate the eye of a patient, and images are acquired by the digital camera. The device is designed to have minimal risk to the patient and user, and the results are immediately displayed on the LCD screen. Although there were some variations in the make of the

Conclusion

Automated pupillometry can serve as a useful tool for accurate measurement of pupillary reactivity in the neuroICU and ICU patients and provide prognostic information. It also can provide a more accurate time and date record of these measurements and shorten time to intervention. However, all studies done thus far have included small sample sizes. Moreover, many of these studies were aimed at neurosurgical and trauma patients. More data are needed on the use of automated pupillometry in nonhead

Recommendation

Automated pupillometry could have additive value in pupillary examinations and in determining neurologic outcomes and prognosis in critically ill patients (low quality of evidence; strong recommendation).

Automated pupillometry monitoring should be considered for all patients admitted to an ICU (low quality evidence; strong recommendation).

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