Intermittent CSF drainage and rapid EVD weaning approach after subarachnoid hemorrhage: association with fewer VP shunts and shorter length of stay.

OBJECTIVE: There is variability and uncertainty about the optimal approach to the management and discontinuation of an external ventricular drain (EVD) after subarachnoid hemorrhage (SAH). Evidence from single-center randomized trials suggests that intermittent CSF drainage and rapid EVD weans are safe and associated with shorter ICU length of stay (LOS) and fewer EVD complications. However, a recent survey revealed that most neurocritical care units across the United States employ continuous CSF drainage with a gradual wean strategy. Therefore, the authors sought to determine the optimal EVD management approach at their institution. METHODS: The authors reviewed records of 200 patients admitted to their institution from 2010 to 2016 with aneurysmal SAH requiring an EVD. In 2014, the neurocritical care unit of the authors' institution revised the internal EVD management guidelines from a continuous CSF drainage with gradual wean approach (continuous/gradual) to an intermittent CSF drainage with rapid EVD wean approach (intermittent/rapid). The authors performed a retrospective multivariable analysis to compare outcomes before and after the guideline change. RESULTS: The authors observed a significant reduction in ventriculoperitoneal (VP) shunt rates after changing to an intermittent CSF drainage with rapid EVD wean approach (13% intermittent/rapid vs 35% continuous/gradual, OR 0.21, p = 0.001). There was no increase in delayed VP shunt placement at 3 months (9.3% vs 8.6%, univariate p = 0.41). The intermittent/rapid EVD approach was also associated with a shorter mean EVD duration (10.2 vs 15.6 days, p < 0.001), shorter ICU LOS (14.2 vs 16.9 days, p = 0.001), shorter hospital LOS (18.2 vs 23.7 days, p < 0.0001), and lower incidence of a nonfunctioning EVD (15% vs 30%, OR 0.29, p = 0.006). The authors found no significant differences in the rates of symptomatic vasospasm (24.6% vs 20.2%, p = 0.52) or ventriculostomy-associated infections (1.3% vs 8.8%, OR 0.30, p = 0.315) between the 2 groups. CONCLUSIONS: An intermittent CSF drainage with rapid EVD wean approach is associated with fewer VP shunt placements, fewer complications, and shorter LOS compared to a continuous CSF drainage with gradual EVD wean approach. There is a critical need for prospective multicenter studies to determine if the authors' experience is generalizable to other centers.

Performance of Spectrogram-Based Seizure Identification of Adult EEGs by Critical Care Nurses and Neurophysiologists.

PURPOSE: Continuous EEG screening using spectrograms or compressed spectral arrays (CSAs) by neurophysiologists has shorter review times with minimal loss of sensitivity for seizure detection when compared with visual analysis of raw EEG. Limited data are available on the performance characteristics of CSA-based seizure detection by neurocritical care nurses. METHODS: This is a prospective cross-sectional study that was conducted in two academic neurocritical care units and involved 33 neurointensive care unit nurses and four neurophysiologists. RESULTS: All nurses underwent a brief training session before testing. Forty two-hour CSA segments of continuous EEG were reviewed and rated for the presence of seizures. Two experienced clinical neurophysiologists masked to the CSA data performed conventional visual analysis of the raw EEG and served as the gold standard. The overall accuracy was 55.7% among nurses and 67.5% among neurophysiologists. Nurse seizure detection sensitivity was 73.8%, and the false-positive rate was 1-per-3.2 hours. Sensitivity and false-alarm rate for the neurophysiologists was 66.3% and 1-per-6.4 hours, respectively. Interrater agreement for seizure screening was fair for nurses (Gwet AC1 statistic: 43.4%) and neurophysiologists (AC1: 46.3%). CONCLUSIONS: Training nurses to perform seizure screening utilizing continuous EEG CSA displays is feasible and associated with moderate sensitivity. Nurses and neurophysiologists had comparable sensitivities, but nurses had a higher false-positive rate. Further work is needed to improve sensitivity and reduce false-alarm rates.

Clinical Development and Implementation of an Institutional Guideline for Prospective EEG Monitoring and Reporting of Delayed Cerebral Ischemia.

Delayed cerebral ischemia (DCI) is the most common and disabling complication among patients admitted to the hospital for subarachnoid hemorrhage (SAH). Clinical and radiographic methods often fail to detect DCI early enough to avert irreversible injury. We assessed the clinical feasibility of implementing a continuous EEG (cEEG) ischemia monitoring service for early DCI detection as part of an institutional guideline. An institutional neuromonitoring guideline was designed by an interdisciplinary team of neurocritical care, clinical neurophysiology, and neurosurgery physicians and nursing staff and cEEG technologists. The interdisciplinary team focused on (1) selection criteria of high-risk patients, (2) minimization of safety concerns related to prolonged monitoring, (3) technical selection of quantitative and qualitative neurophysiologic parameters based on expert consensus and review of the literature, (4) a structured interpretation and reporting methodology, prompting direct patient evaluation and iterative neurocritical care, and (5) a two-layered quality assurance process including structured clinician interviews assessing events of neurologic worsening and an adjudicated consensus review of neuroimaging and medical records. The resulting guideline's clinical feasibility was then prospectively evaluated. The institutional SAH monitoring guideline used transcranial Doppler ultrasound and cEEG monitoring for vasospasm and ischemia monitoring in patients with either Fisher group 3 or Hunt-Hess grade IV or V SAH. Safety criteria focused on prevention of skin breakdown and agitation. Technical components included monitoring of transcranial Doppler ultrasound velocities and cEEG features, including quantitative alpha:delta ratio and percent alpha variability, qualitative evidence of new focal slowing, late-onset epileptiform activity, or overall worsening of background. Structured cEEG reports were introduced including verbal communication for findings concerning neurologic decline. The guideline was successfully implemented over 27 months, during which neurocritical care physicians referred 71 SAH patients for combined transcranial Doppler ultrasound and cEEG monitoring. The quality assurance process determined a DCI rate of 48% among the monitored population, more than 90% of which occurred during the duration of cEEG monitoring (mean 6.9 days) beginning 2.7 days after symptom onset. An institutional guideline implementing cEEG for SAH ischemia monitoring and reporting is feasible to implement and efficiently identify patients at high baseline risk of DCI during the period of monitoring.