Quantitative Pupillometry: Clinical Applications for the Internist.

From the time of Galen, examining of the pupillary light reflex has been a standard of care across the continuum of healthcare. The growing body of evidence overwhelmingly supports the use of quantitative pupillometry over subject examination with flashlight or penlight. At current time, pupillometers have become standard-of-care in many hospitals across six continents. This review paper provides an overview and rationale for pupillometer use and highlights literature supporting pupillometer derived measures of the pupillary light reflex in both neurological and non-neurological patients across the healthcare continuum.

Prospective study examining the impact of cerebral angiography on quantitative pupillometer values in the interventional radiology suite.

OBJECTIVES: The purpose of this pilot study was to obtain baseline quantitative pupillometry (QP) measurements before and after catheter-directed cerebral angiography (DCA) to explore the hypothesis that cerebral angiography is an independent predictor of change in pupillary light reflex (PLR) metrics. DESIGN: This was a prospective, observational pilot study of PLR assessments obtained using QP 30 min before and after DCA. All patients had QP measurements performed with the NPi-300 (Neuroptics) pupillometer. SETTING: Recruitment was done at a single-centre, tertiary-care academic hospital and comprehensive stroke centre in Dallas, Texas. PARTICIPANTS: Fifty participants were recruited undergoing elective or emergent angiography. Inclusion criteria were a physician-ordered interventional neuroradiological procedure, at least 18 years of age, no contraindications to PLR assessment with QP, and nursing transport to and from DCA. Patients with a history of eye surgery were excluded. MAIN OUTCOME MEASURES: Difference in PLR metric obtained from QP 30 min before and after DCA. RESULTS: Statistically significant difference was noted in the pre and post left eye readings for the minimum pupil size (a.k.a., pupil diameter on maximum constriction). The mean maximum constriction diameter prior to angiogram of 3.2 (1.1) mm was statistically larger than after angiogram (2.9 (1.0) mm; p<0.05); however, this was not considered clinically significant. Comparisons for all other PLR metrics pre and post angiogram demonstrated no significant difference. Using change in NPi pre and post angiogram (Δpre=0.05 (0.77) vs Δpost=0.08 (0.67); p=0.62), we calculated the effect size as 0.042. Hence, detecting a statistically significant difference in NPi, if a difference exists, would require a sample size of ~6000 patients. CONCLUSIONS: Our study provides supportive data that in an uncomplicated angiogram, even with intervention, there is no effect on the PLR.

Original Research: Practice Variations in Documenting Neurologic Examinations in Non-Neuroscience ICUs.

BACKGROUND: In critical care units, the neurologic examination (neuro exam) is used to detect changes in neurologic function. Serial neuro exams are a hallmark of monitoring in neuroscience ICUs. But less is known about neuro exams that are performed in non-neuroscience ICUs. This knowledge gap likely contributes to the insufficient guidance on what constitutes an adequate neuro exam for patients admitted to a non-neuroscience ICU. PURPOSE: The study purpose was to explore existing practices for documenting neuro exams in ICUs that don't routinely admit patients with a primary neurologic injury. METHODS: A single-center, prospective, observational study examined documented neuro exams performed in medical, surgical, and cardiovascular ICUs. A comprehensive neuro exam assesses seven domains that can be divided into 20 components. In this study, each component was scored as present (documentation was found) or absent (documentation was not found); a domain was scored as present if one or more of its components had been documented. RESULTS: There were 1,482 assessments documented on 120 patients over a one-week period. A majority of patients were male (56%), White (71%), non-Hispanic (77%), and over 60 years of age (50%). Overall, assessments of the domains of consciousness, injury severity, and cranial nerve function were documented 80% of the time or more. Assessments of the domains of pain, motor function, and sensory function were documented less than 60% of the time, and that of speech less than 5% of the time. Statistically significant differences in documentation were found between the medical, surgical, and cardiovascular ICUs for the domains of speech, cranial nerve function, and pain. There were no significant differences in documentation frequency between day and night shift nurses. Documentation practices were significantly different for RNs versus providers. CONCLUSIONS: Our findings show that the frequency and specific components of neuro exam documentation vary significantly across nurses, providers, and ICUs. These findings are relevant for nurses and providers and may help to improve guidance for neurologic assessment of patients in non-neurologic ICUs. Further studies exploring variance in documentation practices and their implications for courses of treatment and patient outcomes are warranted.

Relationship Between Automated Pupillometry Measurements and Ventricular Volume in Patients With Aneurysmal Subarachnoid Hemorrhage.

ABSTRACT: INTRODUCTION: Pupillometry allows for a standardized assessment of the pupillary light reflex. Acute hydrocephalus (HCP) is a common complication in patients with aneurysmal subarachnoid hemorrhage (aSAH). HCP may affect the pupillary light reflex because of increased intracranial pressure or dilation of the rostral aqueduct. The association between the pupillary light reflex and HCP in aSAH patients has not been clearly established. The objective of this study is to analyze the correlation between the Neurological Pupil index (NPi) and the degree of HCP in aSAH patients. METHODS: The Establishing Normative Data for Pupillometer Assessments in Neuroscience Intensive Care Registry is a prospectively collected database of pupillometry readings in patients admitted to 4 different neurological intensive care units. Patients in the registry with aSAH who had pupillometry assessments within 6 hours of a brain computed tomography were studied. The degree of HCP was quantified using the HCP score, and the relationship between the NPi and HCP was analyzed after controlling for confounders. RESULTS: A total of 43 patients were analyzed (mean age, 54 ± 15 years; 53.2% male; mean HCP score, 5.3 ± 3.8). Thirty-eight patients had HCP. Mean NPi for the right eye was 4.02 (±1.2), and that for the left eye was 3.7 (±1.5). After adjusting for age, sex, race, and sedation, there was no significant correlation between HCP and NPi (right eye: r = 0.12, P = .44; left eye: r = 0.04, P = .8). CONCLUSION: In patients with aSAH, NPi was not correlated with HCP score. A small sample size could be a limitation of this study. Additional studies are needed to characterize the clinical significance of pupillometry in the evaluation of patients with aSAH and HCP.

A differential of the left eye and right eye neurological pupil index is associated with discharge modified Rankin scores in neurologically injured patients.

BACKGROUND: Automated infrared pupillometry (AIP) and the Neurological Pupil index (NPi) provide an objective means of assessing and trending the pupillary light reflex (PLR) across a broad spectrum of neurological diseases. NPi quantifies the PLR and ranges from 0 to 5; in healthy individuals, the NPi of both eyes is expected to be ≥ 3.0 and symmetric. AIP values demonstrate emerging value as a prognostic tool with predictive properties that could allow practitioners to anticipate neurological deterioration and recovery. The presence of an NPi differential (a difference ≥ 0.7 between the left and right eye) is a potential sign of neurological abnormality. METHODS: We explored NPi differential by considering the modified Rankin Score at discharge (DC mRS) among patients admitted to neuroscience intensive care units (NSICU) of 4 U.S. and 1 Japanese hospitals and for two cohorts of brain injuries: stroke (including subarachnoid hemorrhage, intracerebral hemorrhage, acute ischemic stroke, and aneurysm, 1,200 total patients) and 185 traumatic brain injury (TBI) patients for a total of more than 54,000 pupillary measurements. RESULTS: Stroke patients with at least 1 occurrence of an NPi differential during their NSICU stay have higher DC mRS scores (3.9) compared to those without an NPi differential (2.7; P < .001). Patients with TBI and at least 1 occurrence of an NPi differential during their NSICU stay have higher discharge modified Rankin Scale scores (4.1) compared to those without an NPi differential (2.9; P < .001). When patients experience both abnormalities, abnormal (NPi < 3.0) and an NPi differential, the latter has an anticipatory relationship with respect to the former (P < .001 for z-score skewness analysis). Finally, our analysis confirmed ≥ 0.7 as the optimal cutoff value for the NPi differential (AUC = 0.71, P < .001). CONCLUSION: The NPi differential is an important factor that clinicians should consider when managing critically ill neurological injured patients admitted to the neurocritical care units. TRIAL REGISTRATION: NCT02804438 , Date of Registration: June 17, 2016.

Posterior reversible encephalopathy syndrome in carcinoid tumor.

This case presents a patient with ectopic secretion of adrenocorticotrophic hormone from a carcinoid tumor resulting in severe hypertension, posterior reversible encephalopathy syndrome (PRES), and refractory status epilepticus. Secondary hypertension may be difficult to identify in critically ill patients. Severely uncontrolled hypertension presenting with PRES caused by Cushing syndrome is rare but should be considered. Management requires the correct diagnosis and specific treatment. A missed or delayed diagnosis can lead to serious consequences and disability.

Neurology Exit Examination System in India: A Survey of Examiners' Perceptions and Recommendations.

Background: The traditional Neurology exit examination in India has remained unchanged over the last few decades. In developed countries, objective evaluation methods have replaced the traditional ones. A need for such methods has not been explored in India. Objective: We aimed to study the perceptions and key recommendations of Neurology examiners on the existing examination pattern. Material and Methods: We conducted an online survey of examiners perceptions and recommendations using a set of 10 multiple-choice questions and an open-ended question. Results: 46 examiners provided completed responses suitable for analysis. Nearly equal proportions (30%) of the examiners had 10 years, 10-25 years and >25 years' experience. 92% were not satisfied with current system, 95% did not find adequate time for correction of theory scripts, 90% felt that theory questions were random, and 95% had legibility issues. 84% felt that the practical exams do not test true learning, 98% felt the examination stress impairs the performance and 85% felt that there are no objective criteria to pass the candidate. 83% felt the current system-needed changes. The key suggestions provided by the examiners to improve the system included objective assessments like MCQ, OSCE, OSLER and DOPS, inclusion of larger number of short answer type questions and periodic internal assessments of the candidates. Conclusions: A vast majority of examiners favoured changes to the current examination system and provided key recommendations. A larger study is needed to extrapolate these findings to the rest of India.

Proceedings of the Second Curing Coma Campaign NIH Symposium: Challenging the Future of Research for Coma and Disorders of Consciousness.

This proceedings article presents actionable research targets on the basis of the presentations and discussions at the 2nd Curing Coma National Institutes of Health (NIH) symposium held from May 3 to May 5, 2021. Here, we summarize the background, research priorities, panel discussions, and deliverables discussed during the symposium across six major domains related to disorders of consciousness. The six domains include (1) Biology of Coma, (2) Coma Database, (3) Neuroprognostication, (4) Care of Comatose Patients, (5) Early Clinical Trials, and (6) Long-term Recovery. Following the 1st Curing Coma NIH virtual symposium held on September 9 to September 10, 2020, six workgroups, each consisting of field experts in respective domains, were formed and tasked with identifying gaps and developing key priorities and deliverables to advance the mission of the Curing Coma Campaign. The highly interactive and inspiring presentations and panel discussions during the 3-day virtual NIH symposium identified several action items for the Curing Coma Campaign mission, which we summarize in this article.

Pilot Study of Neurologic Pupil Index as A Predictor of External Ventricular Drain Clamp Trial Failure After Subarachnoid Hemorrhage.

BACKGROUND: External ventricular drains (EVDs) provide a temporary egress for cerebrospinal fluid (CSF) in patients with symptomatic hydrocephalus following aneurysmal subarachnoid hemorrhage. Before EVD removal, a wean trial, which involves clamping the EVD, is typically attempted to ensure that CSF self-regulation is achieved. Automated infrared pupillometry (AIP) has been shown to detect early neurologic decline. We sought to explore the use of AIP to detect early EVD clamping trial failure. METHODS: This prospective observational pilot study enrolled aneurysmal subarachnoid hemorrhage patients before an EVD clamp trial. On initiating the clamp trial, nurses included hourly AIP assessment in documentation. Clamp trial outcome was based on neurologic examination and neuroimaging. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) models were constructed to explore computed tomography (CT) versus AIP as predictors of clamp trial outcome. RESULTS: Among the 30 subjects enrolled, there were 38 clamping trials and 22 successful EVD removals. CT scan as a predictor of clamp trial was found to have a sensitivity of 68.8% and specificity of 89.5% (PPV = 84.6%, NPV = 77.3%). AIP assessment as a predictor of wean trial outcome was found to have a sensitivity of 58.3% and specificity of 100% (PPV = 100%, NPV = 63.2%). CONCLUSIONS: The pilot study data support that Neurological Pupil index <3 is a potential indicator of early clamp trial failure, but a CT scan has a higher sensitivity and NPV for predicting successful EVD removal. This finding suggests the benefits of including AIP assessments during clamping trials.

Inter-device reliability of the NPi-200 and NPi-300 pupillometers.

The pupillary evaluation is an essential part of the neurological examination. Research suggests that the traditional examination of the pupil with a handheld flashlight has limited interrater reliability. Automated pupillometers were developed to provide an objective scoring of various pupillary parameters. The NPi-200 pupillometer is used for quantitative pupillary examinations, the NPi-300 was launched in July 2021 with enhanced features. The purpose of this study is to compare results from the NPi-200 to the NPi-300 to ensure that data are translatable across both platforms. This study examines the inter-device reliability of the NPi-200 compared to the NPi-300 in two cohorts: 20 patients at risk for cerebral edema and 50 healthy controls. Paired assessments of the devices were made from all participants. Each assessment included bilateral PLR readings within a 5-minute interval. Data showed high agreement between the two devices for the Neurological Pupil Index (NPi) reading (k = 0.94; CI: 0.91-0.99) and for pupil diameter assessment (k = 0.91; CI: 0.87-0.96). There is a very high level of agreement between the NPi-200 and NPi-300 among healthy controls and critically ill patients. Clinicians and researchers can interpret the results from either device equally.

Comparison of Bispectral Index Monitor Data Between Standard Frontal-Temporal Position and Alternative Nasal Dorsum Position in the Intensive Care Unit: A Pilot Study.

ABSTRACT: BACKGROUND: The Bispectral (BIS) monitor is a validated, noninvasive monitor placed over the forehead to titrate sedation in patients under general anesthesia in the operating room. In the neurocritical care unit, there is limited room on the forehead because of incisions, injuries, and other monitoring devices. This is a pilot study to determine whether a BIS nasal montage correlates to the standard frontal-temporal data in this patient population. METHODS: This prospective nonandomized pilot study enrolled 10 critically ill, intubated, and sedated adult patients admitted to the neurocritical care unit. Each patient had a BIS monitor placed over the standard frontal-temporal location and over the alternative nasal dorsum with simultaneous data collected for 24 hours. RESULTS: In the frontal-temporal location, the mean (SD) BIS score was 50.9 (15.0), average minimum BIS score was 47.0 (15.0), and average maximum BIS score was 58.4 (16.7). In the nasal dorsum location, the mean BIS score was 54.8 (21.6), average minimum BIS score was 52.8 (20.9), and average maximum BIS score was 58.0 (22.2). Baseline nonparametric tests showed nonsignificant P values for all variables except for Signal Quality Index. Generalized linear model analysis demonstrated significant differences between the 2 monitor locations (P < .0001). CONCLUSION: The results of this pilot study do not support using a BIS nasal montage as an alternative for patients in the neurocritical care unit.

Nimodipine in Clinical Practice: A Pharmacological Update.

ABSTRACT: INTRODUCTION: Enteral nimodipine provides a neuroprotective effect in patients who have experienced an aneurysmal subarachnoid hemorrhage (aSAH). Nimodipine remains the only US Food and Drug Administration-approved medication for aSAH. CONTENT: Nimodipine has been prescribed for patients with aSAH; however, little is known about factors to consider regarding dosing or patient-specific variables that may affect tolerability to nimodipine. Clinical impact of dose or dosing frequency changes has also been much debated based on risk of hypotension with currently approved dosing regimens. CONCLUSION: This review article addresses factors to consider for dosing and administration, pharmacokinetic and pharmacogenetic impact on nimodipine, and, finally, drug interaction considerations to assess as patients are initiated on enteral nimodipine for aSAH.

Anisocoria Correlates With Injury Severity and Outcomes After Blunt Traumatic Brain Injury.

ABSTRACT: BACKGROUND: Automated infrared pupillometry (AIP) has been shown to be helpful in the setting of aneurysmal subarachnoid hemorrhage and stroke as an indicator of imminent irreversible brain injury. We postulated that the early detection of pupillary dysfunction after light stimulation using AIP may be useful in patients with traumatic brain injury (TBI). METHODS: We performed a retrospective review of the Establishing Normative Data for Pupillometer Assessment in Neuroscience Intensive Care database, a prospectively populated multicenter registry of patients who had AIP measurements taken during their intensive care unit admission. The primary eligibility criterion was a diagnosis of blunt TBI. Ordinal logistic modeling was used to explore the association between anisocoria and daily Glasgow Coma Scale scores and discharge modified Rankin Scale scores from the intensive care unit and from the hospital. RESULTS: Among 118 subjects in the who met inclusion, there were 6187 pupillometer readings. Of these, anisocoria in ambient light was present in 12.8%, and that after light stimulation was present in 9.8%. Anisocoria after light stimulation was associated with worse injury severity (odds ratio [OR], 0.26 [95% confidence interval (CI), 0.14-0.46]), lower discharge Glasgow Coma Scale scores (OR, 0.28 [95% CI, 0.17-0.45]), and lower discharge modified Rankin Scale scores (OR, 0.28 [95% CI, 0.17-0.47]). Anisocoria in ambient light showed a similar but weaker association. CONCLUSION: Anisocoria correlates with injury severity and with patient outcomes after blunt TBI. Anisocoria after light stimulation seems to be a stronger predictor than does anisocoria in ambient light. These findings represent continued efforts to understand pupillary changes in the setting of TBI.

Quantitative pupillometry in patients with traumatic brain injury and loss of consciousness: A prospective pilot study.

OBJECTIVE: Loss of consciousness (LOC) is a hallmark feature in Traumatic Brain Injury (TBI), and a strong predictor of outcomes after TBI. The aim of this study was to describe associations between quantitative infrared pupillometry values and LOC, intracranial hypertension, and functional outcomes in patients with TBI. METHODS: We conducted a prospective study of patients evaluated at a Level 1 trauma center between November 2019 and February 2020. Pupillometry values including the Neurological Pupil Index (NPi), constriction velocity (CV), and dilation velocity (DV) were obtained. RESULTS: Thirty-six consecutive TBI patients were enrolled. The median (range) age was 48 (range 21-86) years. The mean Glasgow Coma Scale score on arrival was 11.8 (SD = 4.0). DV trichotomized as low (<0.5 mm/s), moderate (0.5-1.0 mm/s), or high (>1.0 mm/s) was significantly associated with LOC (P = .02), and the need for emergent intervention (P < .01). No significant association was observed between LOC and NPi (P = .16); nor between LOC and CV (P = .07). CONCLUSIONS: Our data suggests that DV, as a discrete variable, is associated with LOC in TBI. Further investigation of the relationship between discrete pupillometric variables and NPi may be valuable to understand the clinical significance of the pupillary light reflex findings in acute TBI.

Automated Pupillometry as a Triage and Assessment Tool in Patients with Traumatic Brain Injury.

OBJECTIVE: Traumatic brain injury (TBI) is a leading cause of morbidity and mortality in young adults. Automated infrared pupillometry (AIP) has shown promising results in predicting neural damage in aneurysmal subarachnoid hemorrhage and ischemic stroke. We aimed to explore potential uses of AIP in triaging patients with TBI. We hypothesized that a brain injury severe enough to require an intervention would show Neurologic Pupil Index (NPI) changes. METHODS: We conducted a prospective pilot study at a level-1 trauma center between November 2019 and February 2020. AIP readings of consecutive patients seen in the emergency department with blunt TBI and abnormal imaging findings on computed tomography were recorded by the assessing neurosurgery resident. The relationship between NPI and surgical intervention was studied. RESULTS: Thirty-six patients were enrolled, 9 of whom received an intervention. NPI was dichotomized into normal (≥3) versus abnormal (<3) and was predictive of intervention (Fisher exact test; P < 0.0001). Six of the 9 patients had a Glasgow Coma Scale (GCS) score ≤8 and imaging signs of increased intracranial pressure (ICP) and underwent craniectomy (n = 4) or ICP monitor placement (n = 2) and had an abnormal NPI. Three patients underwent ICP monitor placement for GCS score ≤8 in accordance with TBI guidelines despite minimal imaging findings and had a normal NPI. The GCS score of these patients improved within 24 hours, requiring ICP monitor removal. NPI was normal in all patients who did not require intervention. CONCLUSIONS: AIP could be useful in triaging comatose patients after blunt TBI. An NPI ≥3 may be reassuring in patients with no signs of mass effect or increased ICP.

Supratentorial intracerebral hemorrhage volume and other CT variables predict the neurological pupil index.

OBJECTIVES: There is growing interest in the ability of automated infrared pupillometry to assess severity of neurological illness. We studied the correlation between computed tomography (CT) indicators of intracerebral hemorrhage (ICH) severity with objective measures of the pupillary light reflex (PLR), and hypothesized that hemorrhage volume would predict the Neurological Pupil index™ (NPi™), an indicator of pupillary reactivity. METHODS: This study examined data from patients with supratentorial ICH who underwent serial pupillometer evaluations. CT images were examined to determine the location and laterality of the hemorrhage, along with hematoma volume (using the simplified ABC/2 method), midline shift, hydrocephalus score, and modified Graeb score (indicating interventricular hemorrhage). Demographics were examined with standard measures of central tendency, hypotheses with logistic regression, categorical data with Fisher's Exact X2, and multivariate modeling with constructed MAX-R models. RESULTS: Data were gathered from 44 subjects. ICH volume exhibited the strongest correlation with NPi (ipsilateral [r2 = 0.48, p < 0.0001, contralateral [(r2 = 0.39, p < 0.0001]). Horizontal midline shift of the septum pellucidum also correlated with NPi (ipsilateral [r2 = 0.25, p = 0.0006], contralateral [r2 = 0.15, p = 0.0106]), as did shift of the pineal gland (ipsilateral [r2 = 0.21, p = 0.0017], contralateral[r2 = 0.11, p = 0.0328]). ICH volume was the most predictive of abnormal NPi (AUC = 0.85 for ipsilateral and 0.88 for contralateral NPi), and multivariate modeling identified additional independent predictors of NPi. CONCLUSION: ICH volume and shift of midline structures correlate with NPi, and abnormalities in NPi can be predicted by hematoma volume and other CT indicators of ICH severity. Future studies should explore the role of NPi in detecting early hematoma expansion and worsening midline shift.

Methods for Cleaning and Managing a Nurse-Led Registry.

BACKGROUND: Clinical registries provide insight on the quality of patient care by providing data to identify associations and patterns in diagnosis, disease, and treatment. This has led to a push toward using large data sets in healthcare research. Nurse researchers are developing data registries, but most are unaware of how to manage a data registry. This article examines a neuroscience nursing registry to describe a quality control and data management process. DATA QUALITY PROCESS: Our registry contains more than 90 000 rows of data from almost 5000 patients at 4 US hospitals. Data management is a continuous process that consists of 5 phases: screening, data organization, diagnostic, treatment, and missing data. These phases are repeated with each registry update. DISCUSSION: The interdisciplinary approach to data management resulted in high-quality data, which was confirmed by missing data analysis. Most technical errors could be systematically diagnosed and resolved using basic statistical outputs, and fixed in the source file. CONCLUSION: The methods described provide a structured way for nurses and their collaborators to clean and manage registries.

Elevated blood pressure after craniotomy: A prospective observational study.

PURPOSE: Close hemodynamic monitoring after craniotomy is routine given risk for post-operative hypertension, systemic and neurological complications. Patient and peri-operative variables associated with increased risk of post-craniotomy hypertension and complications are not well understood. Our analysis aims to estimate the incidence and prevalence of post-craniotomy hypertension, its time course, contributing factors, and post-craniotomy complications. MATERIAL AND METHODS: This is a prospective study of patients admitted to the Neurosurgical Intensive Care Unit after an elective craniotomy. Variables associated with pre-surgical risk, demographics, and post-operative care were analyzed. RESULTS: A total of 282 patients were included in the final analysis, 44% had pre-existing hypertension. Post-craniotomy hypertension was seen in 21%, with a higher incidence in patients with pre-existing hypertension (p < .001), smaller craniotomies (p = .0035), and increased use of analgesic medications (p < .001). History of hypertension was the only independent risk factor for post-craniotomy hypertension in a multivariate regression model. Patients who developed post-craniotomy hypertension, showed a significant increase in length of stay, number and duration of antihypertensive treatment. However, post-craniotomy hypertension was not associated with a higher incidence of other post-operative complications. CONCLUSIONS: Development of hypertension after craniotomy is multi-factorial. In this prospective study, a prior history of hypertension was the only associated independent risk factor.

Early automated infrared pupillometry is superior to auditory brainstem response in predicting neurological outcome after cardiac arrest.

AIM: Assessment of brainstem function plays a key role in predicting the neurological outcome after cardiac arrest. However, the relationship of the two quantitative brainstem assessment methods-automated infrared pupillometry (AIP) and auditory brainstem response (ABR)-with neurological prognoses remains unclear. This study compares the prognostic value of AIP and ABR after cardiopulmonary arrest. METHODS: This retrospective observational study included 124 comatose patients after cardiopulmonary arrest. ABR and AIP measurements were performed simultaneously within 72 h after return of spontaneous circulation. Neurological outcome was assessed at discharge by estimating the cerebral performance category (CPC) score; favourable neurological outcome (CPC score, 1-2) or poor neurological outcome (CPC score, 3-5). The correlation of each AIP parameter and ABR I-V wave latency was tested using Pearson's product moment correlation coefficient, and the prognostic value was compared using the area under the receiver operating characteristics curve (AUC). RESULTS: Pupillary light reflex (PLR) was not detected in 69 patients, and ABR wave V was not detected in 47 patients. All these patients had poor neurological outcome. Among those whose PLR and ABR could be measured, each AIP parameter had a tendency to be correlated with ABR I-V wave latency. Pupil constriction velocity provided the greatest AUC (0.819), with 81% sensitivity and 77% specificity. ABR I-V wave latency provided extremely low AUC (0.560). CONCLUSIONS: Although AIP and ABR were correlated, the AIP measures were superior in predicting the neurological outcome after cardiac arrest as compared with the ABR measures.