Noninvasive Intracranial Pressure Monitoring: Are We There Yet?

There is an urgent unmet need for a reliable noninvasive tool to detect elevations in intracranial pressure (ICP) above guideline-recommended thresholds for treatment. Gold standard invasive ICP monitoring is unavailable in many settings, including resource-limited environments, and in situations such as liver failure in which coagulopathy increases the risk of invasive monitoring. Although a large number of noninvasive techniques have been evaluated, this article reviews the potential clinical role, if any, of the techniques that have undergone the most extensive evaluation and are already in clinical use. Elevations in ICP transmitted through the subarachnoid space result in distension of the optic nerve sheath. The optic nerve sheath diameter (ONSD) can be measured with ultrasound, and an ONSD threshold can be used to detect elevated ICP. Although many studies suggest this technique accurately detects elevated ICP, there is concern for risk of bias and variations in ONSD thresholds across studies that preclude routine use of this technique in clinical practice. Multiple transcranial Doppler techniques have been used to assess ICP, but the best studied are the pulsatility index and the Czosnyka method to estimate cerebral perfusion pressure and ICP. Although there is inconsistency in the literature, recent prospective studies, including an international multicenter study, suggest the estimated ICP technique has a high negative predictive value (> 95%) but a poor positive predictive value (≤ 30%). Quantitative pupillometry is a sensitive and objective method to assess pupillary size and reactivity. Proprietary indices have been developed to quantify the pupillary light response. Limited data suggest these quantitative measurements may be useful for the early detection of ICP elevation. No current noninvasive technology can replace invasive ICP monitoring. Where ICP monitoring is unavailable, multimodal noninvasive assessment may be useful. Further innovation and research are required to develop a reliable, continuous technique of noninvasive ICP assessment.

Apnea Testing on Conventional Mechanical Ventilation During Brain Death Evaluation.

INTRODUCTION: The use of continuous positive airway pressure has been shown to improve the tolerance of the apnea test, a critical component of brain death evaluation. The ability to deactivate the apnea backup setting has made apnea testing possible using several conventional mechanical ventilators. Our goal was to evaluate the safety and efficacy of apnea testing performed on mechanical ventilation, compared with the oxygen insufflation technique, for the determination of brain death. METHODS: This was a retrospective study. In 2016, our institution approved a change in policy to permit apnea testing on conventional mechanical ventilation. We examined the records of consecutive adults who underwent apnea testing as part of the brain death evaluation process between 2016 and 2022. Using an apnea test technique was decided at the discretion of the attending physician. Outcomes were successful apnea test and the occurrence of patient instability during the test. This included oxygen desaturation (SpO2) < 90%, hypotension (mean arterial pressure < 65 mm Hg despite titration of vasopressor), cardiac arrhythmia, pneumothorax, and cardiac arrest. RESULTS: Ninety-two adult patients underwent apnea testing during the study period: 58 (63%) with mechanical ventilation, 32 (35%) with oxygen insufflation, and 2 (2%) lacked documentation of technique. Apnea tests could not be completed successfully in 3 of 92 (3%) patients-two patients undergoing the oxygen insufflation technique (one patient with hypoxemia and one patient with hypotension) and one patient on mechanical ventilation (aborted for hemodynamic instability). Hypoxemia occurred in 4 of 32 (12.5%) patients with oxygen insufflation and in zero patients on mechanical ventilation (p = 0.01). Hypotension occurred during 3 of 58 (5%) tests with mechanical ventilation and 4 of 32 (12.5%) tests with oxygen insufflation (p = 0.24). In multivariate analysis, the use of oxygen insufflation was an independent predictor of patient instability during the apnea test (odds ratio 37.74, 95% confidence interval 2.74-520.14). CONCLUSIONS: Apnea testing on conventional mechanical ventilation is feasible and offers several potential advantages over other techniques.

Guidelines for Neuroprognostication in Critically Ill Adults with Intracerebral Hemorrhage.

BACKGROUND: The objective of this document is to provide recommendations on the formal reliability of major clinical predictors often associated with intracerebral hemorrhage (ICH) neuroprognostication. METHODS: A narrative systematic review was completed using the Grading of Recommendations Assessment, Development, and Evaluation methodology and the Population, Intervention, Comparator, Outcome, Timing, Setting questions. Predictors, which included both individual clinical variables and prediction models, were selected based on clinical relevance and attention in the literature. Following construction of the evidence profile and summary of findings, recommendations were based on Grading of Recommendations Assessment, Development, and Evaluation criteria. Good practice statements addressed essential principles of neuroprognostication that could not be framed in the Population, Intervention, Comparator, Outcome, Timing, Setting format. RESULTS: Six candidate clinical variables and two clinical grading scales (the original ICH score and maximally treated ICH score) were selected for recommendation creation. A total of 347 articles out of 10,751 articles screened met our eligibility criteria. Consensus statements of good practice included deferring neuroprognostication-aside from the most clinically devastated patients-for at least the first 48-72 h of intensive care unit admission; understanding what outcomes would have been most valued by the patient; and counseling of patients and surrogates whose ultimate neurological recovery may occur over a variable period of time. Although many clinical variables and grading scales are associated with ICH poor outcome, no clinical variable alone or sole clinical grading scale was suggested by the panel as currently being reliable by itself for use in counseling patients with ICH and their surrogates, regarding functional outcome at 3 months and beyond or 30-day mortality. CONCLUSIONS: These guidelines provide recommendations on the formal reliability of predictors of poor outcome in the context of counseling patients with ICH and surrogates and suggest broad principles of neuroprognostication. Clinicians formulating their judgments of prognosis for patients with ICH should avoid anchoring bias based solely on any one clinical variable or published clinical grading scale.

Guidelines for neuroprognostication in adults with traumatic spinal cord injury.

BACKGROUND: Traumatic spinal cord injury (tSCI) impacts patients and their families acutely and often for the long term. The ability of clinicians to share prognostic information about mortality and functional outcomes allows patients and their surrogates to engage in decision-making and plan for the future. These guidelines provide recommendations on the reliability of acute-phase clinical predictors to inform neuroprognostication and guide clinicians in counseling adult patients with tSCI or their surrogates. METHODS: A narrative systematic review was completed using Grading of Recommendations Assessment, Development, and Evaluation methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of an appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Timing/Setting question was framed as "When counseling patients or surrogates of critically ill patients with traumatic spinal cord injury, should < predictor, with time of assessment if appropriate > be considered a reliable predictor of < outcome, with time frame of assessment >?" Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an evidence profile and summary of findings, recommendations were based on four Grading of Recommendations Assessment, Development, and Evaluation criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. Good practice recommendations addressed essential principles of neuroprognostication that could not be framed in the Population/Intervention/Comparator/Outcome/Timing/Setting format. Throughout the guideline development process, an individual living with tSCI provided perspective on patient-centered priorities. RESULTS: Six candidate clinical variables and one prediction model were selected. Out of 11,132 articles screened, 369 met inclusion criteria for full-text review and 35 articles met eligibility criteria to guide recommendations. We recommend pathologic findings on magnetic resonance imaging, neurological level of injury, and severity of injury as moderately reliable predictors of American Spinal Cord Injury Impairment Scale improvement and the Dutch Clinical Prediction Rule as a moderately reliable prediction model of independent ambulation at 1 year after injury. No other reliable or moderately reliable predictors of mortality or functional outcome were identified. Good practice recommendations include considering the complete clinical condition as opposed to a single variable and communicating the challenges of likely functional deficits as well as potential for improvement and for long-term quality of life with SCI-related deficits to patients and surrogates. CONCLUSIONS: These guidelines provide recommendations about the reliability of acute-phase predictors of mortality, functional outcome, American Spinal Injury Association Impairment Scale grade conversion, and recovery of independent ambulation for consideration when counseling patients with tSCI or their surrogates and suggest broad principles of neuroprognostication in this context.

Guidelines for Neuroprognostication in Critically Ill Adults with Moderate-Severe Traumatic Brain Injury.

BACKGROUND: Moderate-severe traumatic brain injury (msTBI) carries high morbidity and mortality worldwide. Accurate neuroprognostication is essential in guiding clinical decisions, including patient triage and transition to comfort measures. Here we provide recommendations regarding the reliability of major clinical predictors and prediction models commonly used in msTBI neuroprognostication, guiding clinicians in counseling surrogate decision-makers. METHODS: Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we conducted a systematic narrative review of the most clinically relevant predictors and prediction models cited in the literature. The review involved framing specific population/intervention/comparator/outcome/timing/setting (PICOTS) questions and employing stringent full-text screening criteria to examine the literature, focusing on four GRADE criteria: quality of evidence, desirability of outcomes, values and preferences, and resource use. Moreover, good practice recommendations addressing the key principles of neuroprognostication were drafted. RESULTS: After screening 8125 articles, 41 met our eligibility criteria. Ten clinical variables and nine grading scales were selected. Many articles varied in defining "poor" functional outcomes. For consistency, we treated "poor" as "unfavorable". Although many clinical variables are associated with poor outcome in msTBI, only the presence of bilateral pupillary nonreactivity on admission, conditional on accurate assessment without confounding from medications or injuries, was deemed moderately reliable for counseling surrogates regarding 6-month functional outcomes or in-hospital mortality. In terms of prediction models, the Corticosteroid Randomization After Significant Head Injury (CRASH)-basic, CRASH-CT (CRASH-basic extended by computed tomography features), International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT)-core, IMPACT-extended, and IMPACT-lab models were recommended as moderately reliable in predicting 14-day to 6-month mortality and functional outcomes at 6 months and beyond. When using "moderately reliable" predictors or prediction models, the clinician must acknowledge "substantial" uncertainty in the prognosis. CONCLUSIONS: These guidelines provide recommendations to clinicians on the formal reliability of individual predictors and prediction models of poor outcome when counseling surrogates of patients with msTBI and suggest broad principles of neuroprognostication.

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.

Guidelines for Neuroprognostication in Adults with Guillain-Barré Syndrome.

BACKGROUND: Guillain-Barré syndrome (GBS) often carries a favorable prognosis. Of adult patients with GBS, 10-30% require mechanical ventilation during the acute phase of the disease. After the acute phase, the focus shifts to restoration of motor strength, ambulation, and neurological function, with variable speed and degree of recovery. The objective of these guidelines is to provide recommendations on the reliability of select clinical predictors that serve as the basis of neuroprognostication and provide guidance to clinicians counseling adult patients with GBS and/or their surrogates. METHODS: A narrative systematic review was completed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Time frame/Setting (PICOTS) question was framed as follows: "When counseling patients or surrogates of critically ill patients with Guillain-Barré syndrome, should [predictor, with time of assessment if appropriate] be considered a reliable predictor of [outcome, with time frame of assessment]?" Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an 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: Eight candidate clinical variables and six prediction models were selected. A total of 45 articles met our eligibility criteria to guide recommendations. We recommend bulbar weakness (the degree of motor weakness at disease nadir) and the Erasmus GBS Respiratory Insufficiency Score as moderately reliable for prediction of the need for mechanical ventilation. The Erasmus GBS Outcome Score (EGOS) and modified EGOS were identified as moderately reliable predictors of independent ambulation at 3 months and beyond. Good practice recommendations include consideration of both acute and recovery phases of the disease during prognostication, discussion of the possible need for mechanical ventilation and enteral nutrition during counseling, and consideration of the complete clinical condition as opposed to a single variable during prognostication. CONCLUSIONS: These guidelines provide recommendations on the reliability of predictors of the need for mechanical ventilation, poor functional outcome, and independent ambulation following GBS in the context of counseling patients and/or surrogates and suggest broad principles of neuroprognostication. Few predictors were considered moderately reliable based on the available body of evidence, and higher quality data are needed.

Effect of Early vs Standard Approach to Tracheostomy on Functional Outcome at 6 Months Among Patients With Severe Stroke Receiving Mechanical Ventilation: The SETPOINT2 Randomized Clinical Trial.

Importance: Many patients with severe stroke have impaired airway protective reflexes, resulting in prolonged invasive mechanical ventilation. Objective: To test whether early vs standard tracheostomy improved functional outcome among patients with stroke receiving mechanical ventilation. Design, Setting, and Participants: In this randomized clinical trial, 382 patients with severe acute ischemic or hemorrhagic stroke receiving invasive ventilation were randomly assigned (1:1) to early tracheostomy (≤5 days of intubation) or ongoing ventilator weaning with standard tracheostomy if needed from day 10. Patients were randomized between July 28, 2015, and January 24, 2020, at 26 US and German neurocritical care centers. The final date of follow-up was August 9, 2020. Interventions: Patients were assigned to an early tracheostomy strategy (n = 188) or to a standard tracheostomy (control group) strategy (n = 194). Main Outcomes and Measures: The primary outcome was functional outcome at 6 months, based on the modified Rankin Scale score (range, 0 [best] to 6 [worst]) dichotomized to a score of 0 (no disability) to 4 (moderately severe disability) vs 5 (severe disability) or 6 (death). Results: Among 382 patients randomized (median age, 59 years; 49.8% women), 366 (95.8%) completed the trial with available follow-up data on the primary outcome (177 patients [94.1%] in the early group; 189 patients [97.4%] in the standard group). A tracheostomy (predominantly percutaneously) was performed in 95.2% of the early tracheostomy group in a median of 4 days after intubation (IQR, 3-4 days) and in 67% of the control group in a median of 11 days after intubation (IQR, 10-12 days). The proportion without severe disability (modified Rankin Scale score, 0-4) at 6 months was not significantly different in the early tracheostomy vs the control group (43.5% vs 47.1%; difference, -3.6% [95% CI, -14.3% to 7.2%]; adjusted odds ratio, 0.93 [95% CI, 0.60-1.42]; P = .73). Of the serious adverse events, 5.0% (6 of 121 reported events) in the early tracheostomy group vs 3.4% (4 of 118 reported events) were related to tracheostomy. Conclusions and Relevance: Among patients with severe stroke receiving mechanical ventilation, a strategy of early tracheostomy, compared with a standard approach to tracheostomy, did not significantly improve the rate of survival without severe disability at 6 months. However, the wide confidence intervals around the effect estimate may include a clinically important difference, so a clinically relevant benefit or harm from a strategy of early tracheostomy cannot be excluded. Trial Registration: ClinicalTrials.gov Identifier: NCT02377167.

Safety and Efficacy of 23.4% Sodium Chloride Administered via Peripheral Venous Access for the Treatment of Cerebral Herniation and Intracranial Pressure Elevation.

BACKGROUND: Sodium chloride (NaCl) 23.4% solution has been shown to reduce intracranial pressure (ICP) and reverse transtentorial herniation. A limitation of 23.4% NaCl is its high osmolarity (8008 mOsm/l) and the concern for tissue injury or necrosis following extravasation when administered via peripheral venous access. The use of this agent is therefore often limited to central venous or intraosseous routes of administration. Our objective was to evaluate the safety and efficacy of administration of 23.4% NaCl via peripheral venous access compared with administration via central venous access. METHODS: We reviewed pharmacy records to identify all administrations of 23.4% NaCl at our institution between December 2017 and February 2020. Medical records were then reviewed to identify complications, such as extravasation, soft tissue injury or necrosis, hypotension (mean arterial pressure less than 65 mm Hg), pulmonary edema, hemolysis, and osmotic demyelination. We also compared the change in physiological variables, such as ICP, mean arterial pressure, cerebral perfusion pressure, and heart rate, as well as laboratory values, such as sodium, chloride, bicarbonate, creatinine, and hemoglobin, following administration of 23.4% NaCl via the peripheral and central venous routes. RESULTS: We identified 299 administrations of 23.4% NaCl (242 central and 57 peripheral) in 141 patients during the study period. There was no documented occurrence of soft tissue injury or necrosis in any patient. One patient developed hypotension following central administration. Among the 38 patients with ICP monitoring at the time of drug administration, there was no significant difference in median ICP reduction (- 13 mm Hg [central] vs. - 24 mm Hg [peripheral], p = 0.21) or cerebral perfusion pressure augmentation (16 mm Hg [central] vs. 15 mm Hg [peripheral], p = 0.87) based on route of administration. CONCLUSIONS: Peripheral venous administration of 23.4% NaCl is safe and achieves a reduction in ICP equivalent to that achieved by administration via central venous access.

A Prospective Study of Optic Nerve Ultrasound for the Detection of Elevated Intracranial Pressure in Severe Traumatic Brain Injury.

OBJECTIVES: Intracranial pressure monitoring plays a critical role in the management of severe traumatic brain injury. Our objective was to evaluate the accuracy of optic nerve sheath diameter as a noninvasive screening test for the detection of elevated intracranial pressure and prediction of intracranial pressure treatment intensity. DESIGN: Prospective, blinded study of diagnostic accuracy. SETTING: Neurotrauma ICU. SUBJECTS: Consecutive patients with severe traumatic brain injury. INTERVENTIONS: Optic nerve ultrasound was performed daily and optic nerve ultrasound measured at the point-of-care as well as remotely by an expert blinded to all patient details. Optic disc elevation was also measured. The index test was the highest remote-expert optic nerve ultrasound for the admission. The reference standard was the concurrent invasive intracranial pressure, with test-positivity set at intracranial pressure greater than 22 mm Hg. A priori the minimally acceptable sensitivity threshold was 90% with corresponding specificity 60%. We also evaluated the ability of optic nerve ultrasound to predict a therapeutic intensity level greater than 10. MEASUREMENTS AND MAIN RESULTS: One hundred twenty patients were enrolled. The intraclass correlation coefficient between point of care and expert optic nerve sheath diameter after enrollment of 50 subjects was poor at 0.16 (-0.08 to 0.41) but improved to 0.87 (0.81-0.92) for the remaining subjects after remedial training. The area under the curve of the receiver operating characteristic curve of the highest expert-measured optic nerve sheath diameter to detect intracranial pressure greater than 22 mm Hg was 0.81 (0.73-0.87); area under the curve for prediction of therapeutic intensity level greater than 10 was 0.51 (0.42-0.60). Optic nerve sheath diameter greater than 0.72 demonstrated sensitivity 82% (48-98%) and specificity 79% (70-86%) for intracranial pressure greater than 22 mm Hg. The area under the curve of highest measured optic disc elevation to detect intracranial pressure greater than 22 mm Hg was 0.84 (0.76-0.90). Optic disc elevation greater than 0.04 cm attained sensitivity 90% (56-100%) and specificity 71% (61-79%). CONCLUSIONS: While optic nerve sheath diameter demonstrated a modest, statistically significant correlation with intracranial pressure, a predetermined level of diagnostic accuracy to justify routine clinical use as a screening test was not achieved. Measurement of optic disc elevation appears promising for the detection of elevated intracranial pressure, however, verification from larger studies is necessary.

Use of a Novel Negative-Pressure Tent During Bedside Tracheostomy in COVID-19 Patients.

BACKGROUND: Many COVID-19 patients with neurological manifestations and respiratory failure remain dependent on mechanical ventilation and require tracheostomy, which is an aerosol generating procedure (AGP). The risk of SARS-CoV-2 transmission to healthcare staff during AGPs is well documented, and negative-pressure rooms are often unavailable. Innovative techniques to decrease risk to healthcare providers during AGPs are necessary. Our objective was to demonstrate the feasibility of percutaneous dilatational tracheostomy (PDT) performed using a novel prefabricated low-cost negative-pressure tent (AerosolVE). METHODS: Retrospective review of consecutive PDT procedures performed by neurointensivists on intubated adult patients with COVID-19 using the AerosolVE tent during the pandemic under an innovative clinical care protocol. The AerosolVE negative-pressure tent consists of a clear plastic canopy with slits for hand access attached to a U-shaped base with air vents. Air within the tent is drawn through a high-efficiency particulate air filter and released outside. Preliminary testing during simulated AGPs demonstrated negligible escape of particulate matter beyond the tent. The main outcome measure was successful completion of PDT and bronchoscopy within the AerosolVE tent, without complications. RESULTS: The patients were a 53-year-old man with multifocal ischemic stroke and acute respiratory distress syndrome (ARDS), 53-year-old woman with cerebellar hemorrhage and ARDS, and a 69-year-old man with ARDS. Pre-procedure FiO2 requirement was 40-50% and positive end-expiratory pressure (PEEP) 8-12 cm H2O. The tent was successfully positioned around the patient and PDT completed with real-time ultrasound guidance in all 3 patients. Bronchoscopy was performed to confirm tube position and perform pulmonary toilet. No complications occurred. CONCLUSIONS: It is feasible to perform PDT on intubated COVID-19 patients using the AerosolVE negative-pressure tent. This is a promising low-cost device to decrease risk to healthcare providers during AGPs.

Clinical Factors Associated With ICU-Specific Care Following Supratentoral Brain Tumor Resection and Validation of a Risk Prediction Score.

OBJECTIVES: The postoperative management of patients who undergo brain tumor resection frequently occurs in an ICU. However, the routine admission of all patients to an ICU following surgery is controversial. This study seeks to identify the frequency with which patients undergoing elective supratentorial tumor resection require care, aside from frequent neurologic checks, that is specific to an ICU and to determine the frequency of new complications during ICU admission. Additionally, clinical predictors of ICU-specific care are identified, and a scoring system to discriminate patients most likely to require ICU-specific treatment is validated. DESIGN: Retrospective observational cohort study. SETTING: Academic neurosurgical center. PATIENTS: Two-hundred consecutive adult patients who underwent supratentorial brain tumor surgery. An additional 100 consecutive patients were used to validate the prediction score. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Univariate statistics and multivariable logistic regression were used to identify clinical characteristics associated with ICU-specific treatment. Eighteen patients (9%) received ICU-specific care, and 19 (9.5%) experienced new complications or underwent emergent imaging while in the ICU. Factors significantly associated with ICU-specific care included nonelective admission, preoperative Glasgow Coma Scale, and volume of IV fluids. A simple clinical scoring system that included Karnofsky Performance Status less than 70 (1 point), general endotracheal anesthesia (1 point), and any early postoperative complications (2 points) demonstrated excellent ability to discriminate patients who required ICU-specific care in both the derivation and validation cohorts. CONCLUSIONS: Less than 10% of patients required ICU-specific care following supratentorial tumor resection. A simple clinical scoring system may aid clinicians in stratifying the risk of requiring ICU care and could inform triage decisions when ICU bed availability is limited.

Changes in Therapeutic Intensity Level Following Airway Pressure Release Ventilation in Severe Traumatic Brain Injury.

PURPOSE: Airway pressure release ventilation (APRV) utilizes high levels of airway pressure coupled with brief expiratory release to facilitate open lung ventilation. The aim of our study was to evaluate the effects of APRV-induced elevated airway pressure mean in patients with severe traumatic brain injury. MATERIALS AND METHODS: This was a retrospective cohort study at a 424-bed Level I trauma center. Linear mixed effects models were developed to assess the difference in therapeutic intensity level (TIL), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) over time following the application of APRV. RESULTS: The study included 21 epochs of APRV in 21 patients. In the 6-hour epoch following the application of APRV, the TIL was significantly increased ( P = .002) and the ICP significantly decreased ( P = .041) compared to that before 6 hours. There was no significant change in CPP ( P = .42) over time. The baseline static compliance and time interaction was not significant for TIL (χ2 = 0.2 [ df 1], P = .655), CPP (χ2 = 0 [ df 1], P = 1), or ICP (χ2 = 0.1 [ df 1], P = .752). CONCLUSIONS: Application of APRV in patients with severe traumatic brain injury was associated with significantly, but not clinically meaningful, increased TIL and decreased ICP. No significant change in CPP was observed. No difference was observed based on the baseline pulmonary static compliance.

Correction to: Noninvasive Intracranial Pressure Assessment in Acute Liver Failure.

The authors note that the number 14 was inadvertently omitted from the formula listed on page 5 of the article. It currently reads.

Noninvasive Intracranial Pressure Assessment in Acute Liver Failure.

BACKGROUND: Elevated intracranial pressure (ICP) is an important cause of death following acute liver failure (ALF). While invasive ICP monitoring (IICPM) is most accurate, the presence of coagulopathy increases bleeding risk in ALF. Our objective was to evaluate the accuracy of three noninvasive ultrasound-based measures for the detection of concurrent ICP elevation in ALF-optic nerve sheath diameter (ONSD) using optic nerve ultrasound (ONUS); middle cerebral artery pulsatility index (PI) on transcranial Doppler (TCD); and ICP calculated from TCD flow velocities (ICPtcd) using the estimated cerebral perfusion pressure (CPPe) technique. METHODS: In this retrospective study, consecutive ALF patients admitted over a 6-year period who underwent IICPM as well as measurement of ONSD, TCD-PI or ICPtcd were included. ONSD was measured offline by a blinded investigator from deidentified videos. The ability of highest ONSD, TCD-PI, and ICPtcd to detect concurrent invasive ICP > 20 mmHg was assessed using receiver operating characteristic (ROC) curves. The ROC area under the curve (AUC) was calculated with 95% confidence interval (95% CI) and evaluated against the null hypothesis of AUC = 0.5. Noninvasive measures were also evaluated as predictors of in-hospital death. RESULTS: Forty-one ALF patients were admitted during the study period. In total, 27 (66%) underwent IICPM, of these, 23 underwent ONUS and 21 underwent TCD. Eleven out of 23 (48%) patients died (two from intracranial hypertension). Results of ROC analysis for detection of concurrent ICP > 20 mmHg were as follows: ONSD AUC = 0.59 (95% CI 0.37-0.79, p = 0.54); TCD-PI AUC = 0.55 (95% CI 0.34-0.75, p = 0.70); and ICPtcd AUC = 0.90 (0.72-0.98, p < 0.0001). None of the noninvasive measures were significant predictors of death. CONCLUSIONS: In patients with ALF, neither ONSD nor TCD-PI reliably detected concurrent ICP elevation on invasive monitoring. Estimation of ICP (ICPtcd) using the TCD CPPe technique was associated with concurrent ICP elevation. Additional studies of TCD CPPe in larger numbers of ALF patients may prove worthwhile.

Protocol based invasive intracranial pressure monitoring in acute liver failure: feasibility, safety and impact on management.

BACKGROUND: Acute liver failure (ALF) may result in elevated intracranial pressure (ICP). While invasive ICP monitoring (IICPM) may have a role in ALF management, these patients are typically coagulopathic and at risk for intracranial hemorrhage (ICH). Contemporary ICP monitoring techniques and coagulopathy reversal strategies may be associated with a lower risk of hemorrhage. Our objective was to evaluate the safety, feasibility, impact on clinical management and outcomes associated with protocol-directed use of IICPM in ALF. METHODS: Adult patients admitted between June 2011 and October 2016, with ALF and grade-4 encephalopathy with a reasonable likelihood of survival, were eligible for IICPM. The coagulopathy reversal protocol included administration of recombinant Factor VIIa (rFVIIa) and desmopressin, a goal platelet count >50,000/mm3 and fibrinogen >100 mg/dL. Monitor insertion was performed within an hour of the rFVIIa dose. Only intraparenchymal monitors were used. Computed tomography of the brain was performed prior to and within 24 hours of monitor placement. Outcomes of interest included ICH, sustained intracranial hypertension, therapeutic intensity level (TIL) for ICP management, mortality and functional outcome on the Glasgow Outcome Scale (GOS) at discharge and 6 months. RESULTS: A total of 24/37 patients (65%) with ALF underwent IICPM. The most common reason for exclusion was encephalopathy grade <4. Four patients underwent liver transplantation. There was one asymptomatic ICH following IICPM, in a patient who had an excellent outcome. Sustained intracranial hypertension occurred in 13/24 monitored patients (54%), 5/24 (21%) required extreme measures (TIL-4) for ICP control, which were successful in 4 patients: 12/24 patients (50%) died but only 4 deaths (17%) were attributed to intracranial hypertension. Six of the 8 survivors with 6-month follow up had good functional outcome (GOS >3). CONCLUSIONS: Protocol-directed use of IICPM in ALF is feasible, associated with a low incidence of serious complications and has a significant impact on clinical management.

Emergency Neurological Life Support: Airway, Ventilation, and Sedation.

Airway management and ventilation are central to the resuscitation of the neurologically ill. These patients often have evolving processes that threaten the airway and adequate ventilation. Furthermore, intubation, ventilation, and sedative choices directly affect brain perfusion. Therefore, Airway, Ventilation, and Sedation was chosen as an Emergency Neurological Life Support protocol. Topics include airway management, when and how to intubate with special attention to hemodynamics and preservation of cerebral blood flow, mechanical ventilation settings and the use of sedative agents based on the patient's neurological status.