Underestimation of Pupil Size by Critical Care and Neurosurgical Nurses

Describing Anisocoria in Neurocritically Ill Patients

BACKGROUND

Anisocoria (unequal pupil size) has been defined using cut points ranging from greater than 0.3 mm to greater than 2.0 mm for absolute difference in pupil size. This study explored different pupil diameter cut points for assessing anisocoria as measured by quantitative pupillometry before and after light stimulus.

METHODS

An exploratory descriptive study of international registry data was performed. The first observations in patients with paired left and right quantitative pupillometry measurements were included. Measurements of pupil size before and after stimulus with a fixed light source were used to calculate anisocoria.

RESULTS

The sample included 5769 patients (mean [SD] age, 57.5 [17.6] years; female sex, 2558 patients [51.5%]; White race, 3669 patients [75.5%]). Anisocoria defined as pupil size difference of greater than 0.5 mm was present in 1624 patients (28.2%) before light stimulus; 645 of these patients (39.7%) also had anisocoria after light stimulus (P < .001). Anisocoria defined as pupil size difference of greater than 2.0 mm was present in 79 patients (1.4%) before light stimulus; 42 of these patients (53.2%) also had anisocoria after light stimulus (P < .001).

DISCUSSION

The finding of anisocoria significantly differed before and after light stimulus and according to the cut point used. At most cut points, fewer than half of the patients who had anisocoria before light stimulus also had anisocoria after light stimulus.

CONCLUSION

The profound difference in the number of patients adjudicated as having anisocoria using different cut points reinforces the need to develop a universal definition for anisocoria.

Guidelines for Neuroprognostication in Comatose Adult Survivors of Cardiac Arrest

BACKGROUND

Among cardiac arrest survivors, about half remain comatose 72 h following return of spontaneous circulation (ROSC). Prognostication of poor neurological outcome in this population may result in withdrawal of life-sustaining therapy and death. The objective of this article is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling surrogates of comatose cardiac arrest survivors.

METHODS

A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, which included clinical variables and prediction models, were selected based on clinical relevance and the presence of an appropriate body of evidence. The Population, Intervention, Comparator, Outcome, Timing, Setting (PICOTS) question was framed as follows: "When counseling surrogates of comatose adult survivors of cardiac arrest, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of poor functional outcome assessed at 3 months or later?" Additional full-text screening criteria were used to exclude small and lower-quality studies. Following construction of the evidence profile and summary of findings, recommendations were based on four GRADE criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. In addition, good practice recommendations addressed essential principles of neuroprognostication that could not be framed in PICOTS format.

RESULTS

Eleven candidate clinical variables and three prediction models were selected based on clinical relevance and the presence of an appropriate body of literature. A total of 72 articles met our eligibility criteria to guide recommendations. Good practice recommendations include waiting 72 h following ROSC/rewarming prior to neuroprognostication, avoiding sedation or other confounders, the use of multimodal assessment, and an extended period of observation for awakening in patients with an indeterminate prognosis, if consistent with goals of care. The bilateral absence of pupillary light response > 72 h from ROSC and the bilateral absence of N20 response on somatosensory evoked potential testing were identified as reliable predictors. Computed tomography or magnetic resonance imaging of the brain > 48 h from ROSC and electroencephalography > 72 h from ROSC were identified as moderately reliable predictors.

CONCLUSIONS

These guidelines provide recommendations on the reliability of predictors of poor outcome in the context of counseling surrogates of comatose survivors of cardiac arrest and suggest broad principles of neuroprognostication. Few predictors were considered reliable or moderately reliable based on the available body of evidence.

Brimonidine eye drops reveal diminished sympathetic pupillary tone in comatose patients with brain injury

BACKGROUND

There is an urgent need for easy-to-perform bedside measures to detect residual consciousness in clinically unresponsive patients with acute brain injury. Interestingly, the sympathetic control of pupil size is thought to be lost in states of unconsciousness. We therefore hypothesized that administration of brimonidine (an alpha-2-adrenergic agonist) eye drops into one eye should produce a pharmacologic Horner's syndrome if the clinically unresponsive patient is conscious, but not if the patient is unconscious. Here, in a first step to explore this hypothesis, we investigated the potential of brimonidine eye drops to distinguish preserved sympathetic pupillary function in awake volunteers from impairment of sympathetic tone in patients in a coma.

METHODS

We enrolled comatose patients admitted for acute brain injury to one of the intensive care units (ICU) of a tertiary referral center, in whom EEG and/or neuroimaging for all practical purposes had ruled out residual consciousness. Exclusion criteria were deep sedation, medications with known drug interactions with brimonidine, and a history of eye disease. Age- and sex-matched healthy and awake volunteers served as controls. We measured pupils of both eyes, under scotopic conditions, at baseline and five times 5-120 min after administering brimonidine into the right eye, using automated pupillometry. Primary outcomes were miosis and anisocoria at the individual and group levels.

RESULTS

We included 15 comatose ICU patients (seven women, mean age 59 ± 13.8 years) and 15 controls (seven women, mean age 55 ± 16.3 years). At 30 min, miosis and anisocoria were seen in all 15 controls (mean difference between the brimonidine-treated pupil and the control pupil: - 1.31 mm, 95% CI [- 1.51; - 1.11], p < 0.001), but in none (p < 0.001) of the 15 ICU patients (mean difference: 0.09 mm, 95% CI [- 0.12;0.30], p > 0.99). This effect was unchanged after 120 min and remained robust in sensitivity analyses correcting for baseline pupil size, age, and room illuminance.

CONCLUSION

In this proof-of-principle study, brimonidine eye drops produced anisocoria in awake volunteers but not in comatose patients with brain injury. This suggests that automated pupillometry after administration of brimonidine can distinguish between the extremes of the spectrum of consciousness (i.e., fully conscious vs. deeply comatose). A larger study testing the "intermediate zone" of disorders of consciousness in the ICU seems warranted.

Neuromonitoring in Critically Ill Patients

OBJECTIVES

Critically ill patients are at high risk of acute brain injury. Bedside multimodality neuromonitoring techniques can provide a direct assessment of physiologic interactions between systemic derangements and intracranial processes and offer the potential for early detection of neurologic deterioration before clinically manifest signs occur. Neuromonitoring provides measurable parameters of new or evolving brain injury that can be used as a target for investigating various therapeutic interventions, monitoring treatment responses, and testing clinical paradigms that could reduce secondary brain injury and improve clinical outcomes. Further investigations may also reveal neuromonitoring markers that can assist in neuroprognostication. We provide an up-to-date summary of clinical applications, risks, benefits, and challenges of various invasive and noninvasive neuromonitoring modalities.

DATA SOURCES

English articles were retrieved using pertinent search terms related to invasive and noninvasive neuromonitoring techniques in PubMed and CINAHL.

STUDY SELECTION

Original research, review articles, commentaries, and guidelines.

DATA EXTRACTION

Syntheses of data retrieved from relevant publications are summarized into a narrative review.

DATA SYNTHESIS

A cascade of cerebral and systemic pathophysiological processes can compound neuronal damage in critically ill patients. Numerous neuromonitoring modalities and their clinical applications have been investigated in critically ill patients that monitor a range of neurologic physiologic processes, including clinical neurologic assessments, electrophysiology tests, cerebral blood flow, substrate delivery, substrate utilization, and cellular metabolism. Most studies in neuromonitoring have focused on traumatic brain injury, with a paucity of data on other clinical types of acute brain injury. We provide a concise summary of the most commonly used invasive and noninvasive neuromonitoring techniques, their associated risks, their bedside clinical application, and the implications of common findings to guide evaluation and management of critically ill patients.

CONCLUSIONS

Neuromonitoring techniques provide an essential tool to facilitate early detection and treatment of acute brain injury in critical care. Awareness of the nuances of their use and clinical applications can empower the intensive care team with tools to potentially reduce the burden of neurologic morbidity in critically ill patients.

Pupillometry in neurocritical care

Though pupillometer use is becoming more widespread, there is a lack of evidence on its use by nurses in the neurosurgical ICU. This article explores the use of the pupillometer among neurocritical care nurses to better understand their experience and the device's clinical utility.

Effects of a multifaceted neurological assessment educational program in nursing students: A randomized crossover study

AIM

This study aimed to verify the effects of a multifaceted neurological assessment educational program on neurological assessment-related knowledge, skills, communication ability and self-efficacy in nursing students.

BACKGROUND

Nurses should be equipped with optimal neurological assessment competency to ensure quality care for patients with neurological symptoms.

DESIGN

This study involved a waitlist control group with a randomized crossover design.

METHODS

Fourth-year nursing students were randomly assigned to an intervention group (n = 28) or a waitlist control group (n = 27). Pre- and post-intervention differences in neurological assessment knowledge, skills, communication ability and self-efficacy between the intervention and the waitlist control group were analyzed using generalized estimated equations.

RESULTS

The nursing students in the intervention group showed significantly improved knowledge, skills, communication ability and self-efficacy scores compared with those in the waitlist control group. Scores related to knowledge, skills and communication ability were maintained and self-efficacy scores had further increased at 2 weeks after the educational program in the intervention group.

CONCLUSIONS

Our multifaceted neurological assessment educational program is useful for improving nursing students' knowledge, skills, communication ability and self-efficacy.

Management of moderate to severe traumatic brain injury: an update for the intensivist

Traumatic brain injury (TBI) remains one of the most fatal and debilitating conditions in the world. Current clinical management in severe TBI patients is mainly concerned with reducing secondary insults and optimizing the balance between substrate delivery and consumption. Over the past decades, multimodality monitoring has become more widely available, and clinical management protocols have been published that recommend potential interventions to correct pathophysiological derangements. Even while evidence from randomized clinical trials is still lacking for many of the recommended interventions, these protocols and algorithms can be useful to define a clear standard of therapy where novel interventions can be added or be compared to. Over the past decade, more attention has been paid to holistic management, in which hemodynamic, respiratory, inflammatory or coagulation disturbances are detected and treated accordingly. Considerable variability with regards to the trajectories of recovery exists. Even while most of the recovery occurs in the first months after TBI, substantial changes may still occur in a later phase. Neuroprognostication is challenging in these patients, where a risk of self-fulfilling prophecies is a matter of concern. The present article provides a comprehensive and practical review of the current best practice in clinical management and long-term outcomes of moderate to severe TBI in adult patients admitted to the intensive care unit.

7- year Experience with Automated Pupillometry and Direct Integration with the Hospital Electronic Medical Record

INTRODUCTION

Manual pupillary assessments are an integral part of the neurological evaluation in critically ill patients. Automated pupillometry provides reliable, consistent, and accurate measurement of the light response. We established a computer interface that allow for direct download of pupillometer information to our hospital EMR. Here, we report the single center experience.

METHODS

An interface allowing direct download of pupillometer data to our EMR was developed. We then performed a prospective study using an electronic survey distributed to nurse that used pupillometers in 2015, 2018, and 2020 using a 5-point Likert style format to evaluate the acceptance of this implementation.

RESULTS

In 2015, 22 nurses were surveyed with 50% of the respondents citing lack of pupillometers and 41% citing the labor intensity associated with data entry as the reason for the reluctance to use the pupillometer. The number of nurse responses in 2018 increased to 123 with 78% of nurses finding that the direct download to hospital EMR improved the efficiency of their neurological exams. In 2020, 108 nurses responded with similar responses to those in 2018. We added 3 additional questions regarding utility of the pupillometer during the COVID19 pandemic. 58% of nurses were reassured of the neurologic exam when using the pupillometer in lieu of a full exam to limit infectious exposure.

CONCLUSIONS

This is the first report of the implementation of a direct interface to download pupillometer data to the EMR. The positive effect on nursing workflow and documentation of pupillary findings is discussed.

Exploring the Relationship Between Objective Pupillometry Metrics and Midline Shift

ABSTRACT

BACKGROUND: Pupillary examinations provide early subtle signs of worsening intracranial pathology. Objective pupillomtery assessment, although not yet the standard of care, is considered best practice. However, inconsistent findings from objective pupillometry studies have caused a lack of consensus among clinicians; as such, no clinical guidelines are available to guide clinical use of objective pupillometer devices. To add to the body of evidence, the purpose of this project was to explore the relationship between objective pupillometry metrics and midline shift (MLS). METHODS: A retrospective chart review of pupillometer data was conducted. Midline shift was correlated with objective pupillometry metrics including Neurological Pupil Index (NPi), pupil size, and anisocoria. Midline shift was measured for the patient's initial neuroimaging and with any defined neurological change. Spearman ρ was used for statistical analysis of correlations between pupillometer metrics and MLS measured at both the septum pellucidum and pineal gland. RESULTS: A total of 41 patients were included in the analysis; most were White (58.5%) and male (58.5%), with a mean (SD) age of 58.49 (16.92) years. Spearman ρ revealed statistically significant positive correlations between right pupil NPi and anisocoria with MLS, and significant negative correlations between left pupil NPi and pupil size with MLS. CONCLUSIONS: Results from this project are consistent with previous studies. Objective pupillometry continues to be a valuable component of a comprehensive neurological examination, because it has the ability to discern early and subtle changes in a patient's neurological status, leading to lifesaving interventions.

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.

Measuring pupil size and light response through closed eyelids

Monitoring pupillary size and light-reactivity is a key component of the neurologic assessment in comatose patients after stroke or brain trauma. Currently, pupillary evaluation is performed manually at a frequency often too low to ensure timely alert for irreversible brain damage. We present a novel method for monitoring pupillary size and reactivity through closed eyelids. Our method is based on side illuminating in near-IR through the temple and imaging through the closed eyelid. Successfully tested in a clinical trial, this technology can be implemented as an automated device for continuous pupillary monitoring, which may save staff resources and provide earlier alert to potential brain damage in comatose patients.

Inter-device measurement variability of vital data parameters for keratorefractive and cataract refractive surgery

Introduction:

The measurements of corneal white-to-white (WTW) diameter and pupil size are critical for decision making in refractive surgery. Currently, automatic measurement of keratometry, corneal WTW, and pupil size are implemented in several ocular devices. The purpose of this study was to examine the agreement between two commonly used devices, an autorefractor and an optical biometer, for these parameters.

Methods:

Measurements were performed with both a Lenstar LS-900 and Nidek ARK-1 by an experienced examiner in random order. The devices were placed in close proximity within the same dimly lit room.

Results:

The measurements of 65 right eyes were analyzed. The results of the flat, steep, and mean keratometric reading were not significantly different (p = 0.96, p = 0.90, p = 0.93, respectively). Corneal WTW distances showed only moderate agreement between devices and were found to be significantly different (r = 0.8071; p < 0.01). Pupil diameters showed poor agreement between devices and were significantly different (r = 0.4890; p < 0.01). Agreement between implantable contact lens sizing, based on the measurements obtained by the two devices, was achieved for 19 of the 51 eyes (37.3%).

Conclusion:

We found a significant difference in WTW and pupil size measurements between ARK-1 and Lenstar. Results for both of the devices cannot be considered interchangeable for these data parameters.

Neurological Pupil Index as an Indicator of Irreversible Cerebral Edema: A Case Series

ABSTRACT

BACKGROUND: Assessing the pupillary light reflex is a core component of neurological assessments. Pupil size and reactivity can provide early warning about early neurological decline. Automated infrared pupillometry is noninvasive and easy to use and has greater reliability compared with manual assessments to obtain objective and consistent measurements of pupillary size and reactivity to light. METHODS: This is a case series of 3 patients who had poor baseline clinical neurological examinations. Because it would be more difficult to detect acute neurological deterioration, automated infrared pupillometry and the Neurological Pupil index (NPi) were used in addition to the clinical neurological examination. NPi values < 3.0 prompted further imaging. RESULTS: In each case, abnormal NPi values prompted emergent imaging that confirmed acute cerebral edema and resulted in a change in management and treatment plan. CONCLUSION: The automated infrared pupillometry is a noninvasive monitor that can provide additional objective data in patients with a poor baseline neurological examination in whom it may otherwise be difficult to detect neurological deterioration.

Management of intracranial hypertension following traumatic brain injury: a best clinical practice adoption proposal for intracranial pressure monitoring and decompressive craniectomy. Joint statements by the Traumatic Brain Injury Section of the Italian Society of Neurosurgery (SINch) and the Neuroanesthesia and Neurocritical Care Study Group of the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI)

No robust evidence is provided by literature regarding the management of intracranial hypertension following severe traumatic brain injury (TBI). This is mostly due to the lack of prospective randomized controlled trials (RCTs), the presence of studies containing extreme heterogeneously collected populations and controversial considerations about chosen outcome. A scientific society should provide guidelines for care management and scientific support for those areas for which evidence-based medicine has not been identified. However, RCTs in severe TBI have failed to establish intervention effectiveness, arising the need to make greater use of tools such as Consensus Conferences between experts, which have the advantage of providing recommendations based on experience, on the analysis of updated literature data and on the direct comparison of different logistic realities. The Italian scientific societies should provide guidelines following the national laws ruling the best medical practice. However, many limitations do not allow the collection of data supporting high levels of evidence for intracranial pressure (ICP) monitoring and decompressive craniectomy (DC) in patients with severe TBI. This intersociety document proposes best practice guidelines for this subsetting of patients to be adopted on a national Italian level, along with joint statements from "TBI Section" of the Italian Society of Neurosurgery (SINch) endorsed by the Neuroanesthesia and Neurocritical Care Study Group of the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI). Presented here is a recap of recommendations on management of ICP and DC supported a high level of available evidence and rate of agreement expressed by the assemblies during the more recent consensus conferences, where members of both groups have had a role of active participants and supporters. The listed recommendations have been sent to a panel of experts consisting of the 107 members of the "TBI Section" of the SINch and the 111 members of the Neuroanesthesia and Neurocritical Care Study Group of the SIAARTI. The aim of the survey was to test a preliminary evaluation of the grade of predictable future adherence of the recommendations following this intersociety proposal. The following recommendations are suggested as representing best clinical practice, nevertheless, adoption of local multidisciplinary protocols regarding thresholds of ICP values, drug therapies, hemostasis management and perioperative care of decompressed patients is strongly recommended to improve treatment efficiency, to increase the quality of data collection and to provide more powerful evidence with future studies. Thus, for this future perspective a rapid overview of the role of the multimodal neuromonitoring in the optimal severe TBI management is also provided in this document. It is reasonable to assume that the recommendations reported in this paper will in future be updated by new observations arising from future trials. They are not binding, and this document should be offered as a guidance for clinical practice through an intersociety agreement, taking in consideration the low level of evidence.

Automated Quantitative Pupillometry in the Critically Ill: A Systematic Review of the Literature

OBJECTIVE

A systematic literature search has been performed to identify potential confounders for outcome prediction using pupillary light reflex in adult critically ill patients, as measured by handheld automated pupillometry devices.

METHODS

Three digital databases (PubMed, EmBase, Cochrane) were systematically searched. Articles published between 1990 and 2019 in adult patients using monocular automated handheld devices were considered. Studies were classified according to the Oxford Centre for Evidence-Based Medicine classification (level 1 represents the highest and level 5 the lowest level of evidence). Case reports, original research, and systematic reviews were included and cross-referenced.

RESULTS

With the use of 202 search terms, 58 eligible articles reporting the use of handheld pupillometry in the critically ill could be identified, considering 3,246 patients. The highest level of evidence came from 10 randomized trials and 19 prospective observational studies. The level of evidence was mostly 2 to 3 and highest with studies regarding the potential confounding effects of pain, the use of opioids, and increased intracranial pressure. Additional potential confounders found are selective serotonin reuptake inhibitors, α2-adregenic receptor agonists, and NMDA antagonists.

CONCLUSIONS

The pupillary light reflex is susceptible to factors resulting from underlying comorbid conditions and effects of treatment regimens. Scenarios frequently encountered in critical care such as pain, use of opioids, and proof of increased intracranial pressure have potential confounding effects on outcome and pupillary reflexes. When treatment is guided by pupillary metrics, such confounders put patients at risk of overtreatment or undertreatment. Future research should validate and identify additional confounders, because our review suggests that even more unexplored confounders may exist.

Prognostic value of automated pupillometry: an unselected cohort from a cardiac intensive care unit

Background:

Patients admitted to a cardiac intensive care unit are often unconscious with uncertain prognosis. Automated infrared pupillometry for neurological assessment in the intensive care unit may provide early prognostic information. This study aimed to determine the prognostic value of automated pupillometry in different subgroups of patients in a cardiac intensive care unit with 30-day mortality as the primary endpoint and neurological outcome as the secondary endpoint.

Methods:

A total of 221 comatose patients were divided into three groups: out-of-hospital cardiac arrest, in-hospital cardiac arrest and others (i.e. patients with cardiac diagnoses other than cardiac arrest). Automated pupillometry was serially performed until discharge or death and pupil measurements were analysed using the neurological pupil index algorithm. We applied receiver operating characteristic curves in univariable and multivariable logistic regression models and a calculated Youden index identified neurological pupil index cut-off values at different specificities.

Results:

In out-of-hospital cardiac arrest patients higher neurological pupil index values were independently associated with lower 30-day mortality. The univariable model for 30-day mortality had an area under the curve of 0.87 and the multivariable model achieved an area under the curve of 0.94. The Youden index identified a neurological pupil index cut-off in out-of-hospital cardiac arrest patients of 2.40 for a specificity of 100%. For patients with in-hospital cardiac arrest and other cardiac diagnoses, we found no association between neurological pupil index values and 30-day mortality, and the univariable models showed poor predictive values.

Conclusion:

Automated infrared pupillometry has promising predictive value after out-of-hospital cardiac arrest, but poor predictive value in patients with in-hospital cardiac arrest or cardiac diagnoses unrelated to cardiac arrest. Our data suggest a possible neurological pupil index cut-off of 2.40 for poor outcome in out-of-hospital cardiac arrest patients.

A Systematic Review Assessing the Current State of Automated Pupillometry in the NeuroICU

The aim of this study was to assess the current state of automated pupillometry technology and its application in the neurointensive care unit (neuroICU). We performed a literature search using the PubMed, MEDLINE, and EMBASE databases from database inception through a search end date of October 18, 2018, to identify studies reporting on the use of automated pupillometry in the care of critically ill patients with neurological impairment. Two independent reviewers reviewed all titles and abstracts in two filtering phases. Data were extracted independently. One hundred and forty-one articles/abstracts have been published on the use of automated pupillometry in critical care since inception of the PubMed, MEDLINE, and EMBASE databases. We selected and reviewed 22 full-text articles and 8 abstracts, of which 26 were prospective, 2 were retrospective, and 2 were larger case series. Automated pupillometry increased precision, reliability, and reproducibility compared with the manual pupillary examination; detected subtle and early pupillary changes; detected pupillary changes that indicate a rise, or impending rise, in intracranial pressure detected level of analgesia and depth of sedation; served as a prognostic indicator; estimated the clinical severity of aneurysmal subarachnoid hemorrhage; and served as a noninvasive monitor of response to osmotic therapy. At present, no consensus guidelines exist endorsing routine use of automated pupillometry in the neuroICU. However, an increasing quantity of research supports the usefulness of automated pupillometry in this setting. Further large-scale prospective studies are needed before updated consensus guidelines recommending widespread adoption of automated pupillometry are produced.

Pupillary Light Reflex Is Not Abolished by Epinephrine and Atropine Given During Advanced Cardiac Life Support in Patients Who Achieve Return of Spontaneous Circulation

INTRODUCTION

Absence of pupillary light reflex (PLR) is a well-studied indicator of poor neurologic recovery after cardiac arrest. Interpretation of absent PLR is difficult in patients with hypothermia or hypotension, or who have electrolyte or acid-base disturbances. Additionally, many studies exclude patients who receive epinephrine or atropine from their analysis on the basis that these drugs are thought to abolish the PLR. This observational cohort study assessed for presence or absence of PLR in in-hospital cardiac arrest patients who received epinephrine with or without atropine during advanced cardiac life support and achieved return of spontaneous circulation (ROSC).

METHODS

Pupil size and reactivity were assessed in adult patients who had an in-hospital cardiac arrest, received epinephrine with or without atropine, and achieved ROSC. Measurements were taken using a NeurOptics NPi-200 infrared pupillometer.

RESULTS

Forty patients had pupillometry performed within 1 hour (median: 6 minutes) after ROSC. Of these only 1 (2.5%) patient had nonreactive pupils at first measurement after ROSC. The remaining 39 (97.5%) had reactive pupils. Of the 19 patients who had pupils checked within 3 minutes of ROSC, 100% had reactive pupils. Degree of pupil responsiveness was not correlated with cumulative dose of epinephrine. Ten patients received atropine in addition to epinephrine, including the sole patient with nonreactive pupils. The remaining 9 (90%) had reactive pupils.

CONCLUSION

Epinephrine and atropine do not abolish the PLR in patients who achieve ROSC after in-hospital cardiac arrest. Lack of pupillary response in the post-arrest patient should not be attributed to these drugs.

Interrater reliability in pupillary assessment among intensive care nurses

BACKGROUND

Pupillary abnormalities are a common and reliable finding of brain herniation, ischaemia, and acute brain injury in critically ill patients. Reliable pupil assessment is a vital evaluation in diagnostic and therapeutic procedures for neurocritical patients.

AIM

To evaluate inter-rater reliability of pupillary assessment among intensive care.

METHODS

In this prospective, blind observational study, intensive care nurses and two researchers evaluated the pupil size, reactivity and symmetry of 200 patients with neurosurgery or neurological diseases. A total of 200 pupillary measurement sets were completed independently and blindly.

RESULTS

Three observers -two researchers and the nurse- found fair-to-good and excellent agreements in initial pupil size evaluations of right and left pupils, respectively (ICC = 0.70, 95%; ICC = 0.75, 95%). In patients with pupil size ≥4 mm, the observers found fair-to-good agreements in both right and left pupil initial size measurements (ICC = 0.52; ICC = 0.65). Agreement in pupil symmetry was moderated (K = 0.58), and reactivity was near perfect (K = 0.89) between the three observers.

CONCLUSION

Although the two researchers found near perfect agreement in pupil size, symmetry and reactivity assessment, two researchers and the nurse found moderate agreement in pupil symmetry and fair-to-good agreement in pre- and post-light stimulation pupil size.

Intraosseous Administration of 23.4% NaCl for Treatment of Intracranial Hypertension

BACKGROUND/OBJECTIVE

Prompt treatment of acute intracranial hypertension is vital to preserving neurological function and frequently includes administration of 23.4% NaCl. However, 23.4% NaCl administration requires central venous catheterization that can delay treatment. Intraosseous catheterization is an alternative route of venous access that may result in more rapid administration of 23.4% NaCl.

METHODS

Single-center retrospective analysis of 76 consecutive patients, between January 2015 and January 2018, with clinical signs of intracranial hypertension received 23.4% NaCl through either central venous catheter or intraosseous access.

RESULTS

Intraosseous cannulation was successful on the first attempt in 97% of patients. No immediate untoward effects were seen with intraosseous cannulation. Time to treatment with 23.4% NaCl was significantly shorter in patients with intraosseous access compared to central venous catheter (p < 0.0001).

CONCLUSIONS

Intraosseous cannulation resulted in more rapid administration of 23.4% NaCl with no immediate serious complications. Further investigations to identify the clinical benefits and safety of hypertonic medication administration via intraosseous cannulation are warranted.

Impact of Increased Intracranial Pressure on Pupillometry: A Replication Study

In a diverse, multicenter population, to confirm or refute the conclusions that pupillary light reflex changes are associated with increased intracranial pressure.

Training needs analysis of Korean nurses' neurological assessment competency

Despite the importance of neurological assessment, there is a lack of research directed at nurses' competency in performing these assessments. We aimed to identify nurses' competency levels in performing neurological assessments and prioritize their related training needs using importance-performance analysis. This survey research was conducted and reported based on the enhancing the quality and transparency of health research (EQUATOR) guidelines. A total of 213 nurses participated in a descriptive, cross-sectional survey study. Exploratory factor analysis identified seven factors that together accounted for 70.34% of the variance: cerebral function, signs and symptoms, pathologic reflexes, motor strength, assessment of an unconscious patient, reporting and documentation, and neurological assessment scales. [Correction added on 10 February 2020, after first online publication: the value of the variance has been corrected from '7.34%' to '70.34%' in the preceding sentence.] There were significant gaps between importance and performance for all seven factors. The importance-performance matrix identified the neurological assessment scales factor as a high priority for continuing education. Emergency department nurses reported lower neurological assessment competency when compared with ward and intensive care unit nurses. The analysis of training needs is beneficial for developing programs to enhance neurological assessment competency. Training in neurological assessment scales is a priority for nurses, and they prefer simulation- and practicum-based methods.

Detection of delayed cerebral ischemia using objective pupillometry in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

Cerebral vasospasm causing delayed cerebral ischemia (DCI) is a source of significant morbidity after subarachnoid hemorrhage (SAH). Transcranial Doppler is used at most institutions to detect sonographic vasospasm but has poor positive predictive value for DCI. Automated assessment of the pupillary light reflex has been increasingly used as a reliable way of assessing pupillary reactivity, and the Neurological Pupil Index (NPi) has been shown to decrease hours prior to the clinical manifestation of ischemic injury or herniation syndromes. The aim of this study was to investigate the role of automated pupillometry in the setting of SAH, as a potential adjunct to TCD.

METHODS

Our analysis included patients that had been diagnosed with aneurysmal SAH and admitted to the neuro-intensive care unit of the University of Texas Southwestern Medical Center between November 2015 and June 2017. A dynamic infrared pupillometer was used for all pupillary measurements. An NPi value ranging from 3 to 5 was considered normal, and from 0 to 2.9 abnormal. Sonographic vasospasm was defined as middle cerebral artery velocities greater than 100 cm/sec with a Lindegaard ratio greater than 3 on either side on transcranial Doppler. Most patients had multiple NPi readings daily and we retained the lowest value for our analysis. We aimed to study the association between DCI and sonographic vasospasm, and DCI and NPi readings.

RESULTS

A total of 56 patients were included in the final analysis with 635 paired observations of daily TCD and NPi data. There was no statistically significant association between the NPi value and the presence of sonographic vasospasm. There was a significant association between DCI and sonographic vasospasm, χ2(1) = 6.4112, p = 0.0113, OR 1.6419 (95% CI 1.1163-2.4150), and between DCI and an abnormal decrease in NPi, χ2(1) = 38.4456, p < 0.001, OR 3.3930 (95% CI 2.2789-5.0517). Twelve patients experienced DCI, with 7 showing a decrease of their NPi to an abnormal range. This change occurred > 8 hours prior to the clinical decline 71.4% of the time. The NPi normalized in all patients after treatment of their vasospasm.

CONCLUSIONS

Isolated sonographic vasospasm does not seem to correlate with NPi changes, as the latter likely reflects an ischemic neurological injury. NPi changes are strongly associated with the advent of DCI and could be an early herald of clinical deterioration.

Objective Pupillometry as an Adjunct to Prediction and Assessment for Oculomotor Nerve Injury and Recovery: Potential for Practical Applications

BACKGROUND

Pupillary light reflex examinations are intrinsic to any good neurological examination. Consistent evidence has shown that automated pupillometry assessments provide superior accuracy and interrater correlation compared with bedside eye examinations. Pupillary indexes such as the neurological pupil index (NPI) can also provide several hours of warning before the advent of herniation syndromes or third nerve palsy.

METHODS

We determined the unique temporal relationship between NPI changes and third nerve palsy occurrence and recovery in an initially neurologically intact hospitalized patient. A 53-year-old woman presented with aneurysmal subarachnoid hemorrhage and headaches. Her aneurysm was treated surgically without complications. After lumbar drainage for hydrocephalus, she developed isolated left third nerve palsy that slowly recovered over the following weeks. Pupilometer data were obtained throughout her hospital stay.

RESULTS

A total of 121 pupillary measurement sets were obtained. The NPI had decreased to an abnormal level (<3) 12 hours before she became symptomatic. The NPI also started improving 24 hours before improvement in her clinical examination. The patient did not display signs of neurological dysfunction related to vasospasm during her stay.

CONCLUSION

The NPI seems to reliably correlate with third nerve function and appears to possess predictive temporal properties that could allow practitioners to anticipate neurological injury and recovery. These findings could affect the fields of neurosciences, trauma, military medicine, critical care, and ophthalmology.

Integrating Quantitative Pupillometry Into Regular Care in a Neurotrauma Intensive Care Unit

In the setting of acute traumatic brain injury (TBI), an abnormal pupil assessment may suggest a worsening intracranial lesion. Early detection of pupillary changes may expedite emergent care to improve outcomes. Automated, handheld pupillometers have been commercially available for 20 years, and several studies suggest that their use may facilitate early recognition of worsening injury and intracranial hypertension. The use of pupillometry as a bedside tool in the routine care of patients with severe TBI (Glasgow Coma Scale score ≤ 8) has not been described. We performed a quality improvement project to implement routine use of quantitative pupillometry in our neurotrauma intensive care unit. Nursing staff were trained on device use and the project's aims in a 30-minute in-service session. Nurses caring for severe TBI patients completed standard pupil assessments using (a) a flashlight and (b) a pupillometer to quantify pupil size and reactivity (Neurological Pupil index) every hour. Abnormal results were reported to on-call providers. We administered surveys to evaluate knowledge, practical use of the pupillometer data, and satisfaction with the device every 3 months. Data were available for 22 nurses at 4 separate time points. Staff were positive about their ability to use and understand the device (µ = 8.7 and 9.1, respectively, on a 10-point scale) and reported that it added value to patient care and critical decision-making. Use of automated pupillometry is acceptable to nursing staff in a neurotrauma intensive care unit, and staff believed that pupillometry results enhanced clinical decision-making.

The effects of neurologic assessment E-learning in nurses

BACKGROUND

A firm understanding of the preliminary assessment of a patient with neurological disorders is needed for ensuring optimal patient outcomes.

OBJECTIVES

The purpose of this study is to evaluate the effects of using e-learning on neurologic assessment knowledge, ability, and self-confidence among nurses.

DESIGN

This study used a non-equivalent control group pretest-posttest design.

SETTINGS

Nurses working in the neurology and neurosurgery wards, Republic of Korea PARTICIPANTS: A convenience sample of 50 nurses was assigned to either the experimental group (n=24) or the control group (n=26).

METHODS

The experimental group participated in the self-directed e-learning program related to neurologic assessment, and control group underwent self-directed learning with handout. Knowledge, ability, and self-confidence were measured at pretest and posttest.

RESULTS

There were no significant differences in knowledge (U=270, p=0.399) and self-confidence (U=241.5, p=0.171) between the two groups. Nurses in the experimental group showed higher neurologic assessment ability compared with those in the control group (U=199, p=0.028).

CONCLUSIONS

Self-directed neurologic assessment e-learning induced improvement in the neurologic assessment ability among nurses. Self-directed e-learning can be applied for improving competencies in neurologic assessment.

The use and uptake of pupillometers in the Intensive Care Unit

BACKGROUND

Traumatic brain injury (TBI) is a significant public health issue. Assessing pupil reactivity is a crucial aspect of its management and the pupillometer has been shown to be a more objective tool compared to the standard penlight. Its use, however, is not widespread.

OBJECTIVE

To investigate the paucity in uptake, we examined the frequency of use of pupillometers (NeurOptics^®NPi-100™) amongst Intensive Care Unit (ICU) doctors and nurses, evaluated its user-friendliness and explored barriers to its use.

DESIGN

An online cross-sectional survey.

METHODS

Surveys were distributed five months after the introduction of pupillometers (in May 2015) to ICU doctors and nurses working in a quaternary referral centre providing state services for trauma. The survey included sections on: questions on demographics and experience, methods of conventional pupillary assessment in patients with TBI, experience of using the pupillometer, and questions on barriers to its use. Responses were collated as discrete variables and summarised using counts and proportions. Comparisons among proportions were undertaken using the chi-squared test and reported with 95% confidence intervals.

RESULTS

A total of 79 responses were recorded, predominantly 94.9% (n=75) from nursing staff. A total of 50 (63.3%) responders were using the pupillometers, with a mean frequency-of-use rating of 4.67 out of 10 and a mean user-friendliness rating of 6.28 out of 10. There was no association between frequency of use and user-friendliness (p=0.36). The main identified barriers to its use included a lack of education with regards to its use, a perceived lack of clinical significance, a lack of standardisation of documenting findings, and difficulties with access to disposable patient shields (Smartguards).

CONCLUSIONS

There was good adoption of the technology in the early phases of ICU implementation with user-friendliness rated favourably. In this paper we identify barriers to use and discuss possible solutions to increase clinical utility.