Neurocritical Care of Mechanical Circulatory Support Devices.

PURPOSE OF REVIEW: Mechanical circulatory support (MCS) devices have demonstrated improved survival outcomes in otherwise refractory cardiopulmonary failure but are associated with significant neurologic morbidity and mortality. This review aims to characterize MCS-associated brain injury and discuss the neurocritical care of this population. RECENT FINDINGS: We found no practice guidelines or specific management strategies for the neurocritical care of patients with MCS devices. Acute brain injury was commonly observed in short-term and durable MCS devices. There is emerging evidence that a standardized neurological monitoring and management algorithm for MCS device-associated brain injury is feasible and potentially improves neurological outcomes. While MCS devices are associated with significant neurologic morbidity and mortality, there is scant evidence regarding optimal neuromonitoring and neurocritical care. With the increase in use of MCS devices for both short-term and durable applications, improved outcomes will depend on early identification and intervention of neurologic complications and further research into their pathophysiology.

Association of Outcomes with Model-Based Indices of Cerebral Autoregulation After Pediatric Traumatic Brain Injury.

BACKGROUND: We investigated whether model-based indices of cerebral autoregulation (CA) are associated with outcomes after pediatric traumatic brain injury. METHODS: This was a retrospective analysis of a prospective clinical database of 56 pediatric patients with traumatic brain injury undergoing intracranial pressure monitoring. CA indices were calculated, including pressure reactivity index (PRx), wavelet pressure reactivity index (wPRx), pulse amplitude index (PAx), and correlation coefficient between intracranial pressure pulse amplitude and cerebral perfusion pressure (RAC). Each CA index was used to compute optimal cerebral perfusion pressure (CPP). Time of CPP below lower limit of autoregulation (LLA) or above upper limit of autoregulation (ULA) were computed for each index. Demographic, physiologic, and neuroimaging data were collected. Primary outcome was determined using Pediatric Glasgow Outcome Scale Extended (GOSE-Peds) at 12 months, with higher scores being suggestive of unfavorable outcome. Univariate and multiple linear regression with guided stepwise variable selection was used to find combinations of risk factors that can best explain the variability of GOSE-Peds scores, and the best fit model was applied to the age strata. We hypothesized that higher GOSE-Peds scores were associated with higher CA values and more time below LLA or above ULA for each index. RESULTS: At the univariate level, CPP, dose of intracranial hypertension, PRx, PAx, wPRx, RAC, percent time more than ULA derived for PAx, and percent time less than LLA derived for PRx, PAx, wPRx, and RAC were all associated with GOSE-Peds scores. The best subset model selection on all pediatric patients identified that when accounting for CPP, increased dose of intracranial hypertension and percent time less than LLA derived for wPRx were independently associated with higher GOSE-Peds scores. Age stratification of the best fit model identified that in children less than 2 years of age or 8 years of age or more, percent time less than LLA derived for wPRx represented the sole independent predictor of higher GOSE-Peds scores when accounting for CPP and dose of intracranial hypertension. For children 2 years or younger to less than 8 years of age, dose of intracranial hypertension was identified as the sole independent predictor of higher GOSE-Peds scores when accounting for CPP and percent time less than LLA derived for wPRx. CONCLUSIONS: Increased dose of intracranial hypertension, PRx, wPRx, PAx, and RAC values and increased percentage time less than LLA based on PRx, wPRx, PAx, and RAC are associated with higher GOSE-Peds scores, suggestive of unfavorable outcome. Reducing intracranial hypertension and maintaining CPP more than LLA based on wPRx may improve outcomes and warrants prospective investigation.

Implementation of Multimodality Neurologic Monitoring Reporting in Pediatric Traumatic Brain Injury Management.

BACKGROUND/OBJECTIVE: Multimodality neurologic monitoring (MMM) is an emerging technique for management of traumatic brain injury (TBI). An increasing array of MMM-derived biomarkers now exist that are associated with injury severity and functional outcomes after TBI. A standardized MMM reporting process has not been well described, and a paucity of evidence exists relating MMM reporting in TBI management with functional outcomes or adverse events. METHODS: Prospective implementation of standardized MMM reporting at a single pediatric intensive care unit (PICU) is described that included monitoring of intracranial pressure (ICP), cerebral oxygenation and electroencephalography (EEG). The incidence of clinical decisions made using MMM reporting is described, including timing of neuroimaging, ICP monitoring discontinuation, use of paralytic, hyperosmolar and pentobarbital therapies, neurosurgical interventions, ventilator and CPP adjustments and neurologic prognostication discussions. Retrospective analysis was performed on the association of MMM reporting with initial Glasgow Coma Scale (GCS) and Pediatric Risk of Mortality III (PRISM III) scores, duration of total hospitalization and PICU hospitalization, duration of mechanical ventilation and invasive ICP monitoring, inpatient complications, time with ICP > 20 mmHg, time with cerebral perfusion pressure (CPP) < 40 mmHg and 12-month Glasgow Outcome Scale-Extended Pediatrics (GOSE-Peds) scores. Association of outcomes with MMM reporting was investigated using the Wilcoxon rank-sum test or Fisher's exact test, as appropriate. RESULTS: Eighty-five children with TBI underwent MMM over 6 years, among which 18 underwent daily MMM reporting over a 21-month period. Clinical decision-making influenced by MMM reporting included timing of neuroimaging (100.0%), ICP monitoring discontinuation (100.0%), timing of extubation trials of surviving patients (100.0%), body repositioning (11.1%), paralytic therapy (16.7%), hyperosmolar therapy (22.2%), pentobarbital therapy (33.3%), provocative cerebral autoregulation testing (16.7%), adjustments in CPP thresholds (16.7%), adjustments in PaCO2 thresholds (11.1%), neurosurgical interventions (16.7%) and neurologic prognostication discussions (11.1%). The implementation of MMM reporting was associated with a reduction in ICP monitoring duration (p = 0.0017) and mechanical ventilator duration (p = 0.0018). No significant differences were observed in initial GCS or PRISM III scores, total hospitalization length, PICU hospitalization length, total complications, time with ICP > 20 mmHg, time with CPP < 40 mmHg, use of tier 2 therapy, or 12-month GOS-E Peds scores. CONCLUSION: Implementation of MMM reporting in pediatric TBI management is feasible and can be impactful in tailoring clinical decisions. Prospective work is needed to understand the impact of MMM and MMM reporting systems on functional outcomes and clinical care efficacy.

Right watershed cerebral infarction following neck cannulation for veno-arterial extracorporeal membrane oxygenation in pediatric septic shock: a case series.

Children supported by extracorporeal membrane oxygenation present a high risk of neurological complications. Although carotid cannulation is known to be associated with neurologic injury, conflicting data exist with regard to the predominance of right- or left-sided lesions. We describe here two infants requiring veno-arterial extracorporeal membrane oxygenation for septic shock who encountered right watershed infarction ipsilateral to carotid artery cannulation. Hemodynamic failure seems to be the most probable underlying mechanism. The asymmetry of transcranial Doppler metrics in one case and the low right regional cerebral oxygen saturation value observed soon after right cannulation in both cases suggest an insufficient cerebral collateral flow compensation. The risk of ipsilateral watershed injury should be considered before cervical cannulation, notably in the context of sepsis and an evaluation of the cerebral collateral blood flow before and just after cannulation may be interesting in order to identify infants with higher risk of ipsilateral ischemic lesions.

Neurological monitoring in ECMO patients: current state of practice, challenges and lessons.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) in critically ill patients serves as a management option for end-stage cardiorespiratory failure in medical and surgical conditions. Patients on ECMO are at a high risk of neurologic adverse events including intracranial hemorrhage (ICH), acute ischemic stroke (AIS), seizures, diffuse cerebral edema, and hypoxic brain injury. Standard approaches to neurological monitoring for patients receiving ECMO support can be challenging for multiple reasons, including the severity of critical illness, deep sedation, and/or paralysis. This narrative literature review provides an overview of the current landscape for neurological monitoring in this population. METHODS: A literature search using PubMed was used to aid the understanding of the landscape of published literature in the area of neurological monitoring in ECMO patients. RESULTS: Review articles, cohort studies, case series, and individual reports were identified. A total of 73 varied manuscripts were summarized and included in this review which presents the challenges and strategies for performing neurological monitoring in this population. CONCLUSION: Neurological monitoring in ECMO is an area of interest to many clinicians, however, the literature is limited, heterogenous, and lacks consensus on the best monitoring practices. The evidence for optimal neurological monitoring that could impact clinical decisions and functional outcomes is lacking. Additional studies are needed to identify effective measures of neurological monitoring while on ECMO.

Exploring Spinal Subarachnoid Hemorrhage: A Neurosurgical Case Series.

Spinal subarachnoid hemorrhage (SSAH) is a rare condition that can cause spinal cord or nerve root compression and permanent neurologic damage. The reported etiologies include trauma, vascular malformations or aneurysms, coagulopathies, neoplasms, autoimmune disease, and spontaneous hemorrhage. If there is evidence of neurologic deterioration, it is commonly managed as a surgical emergency, but cases of conservative management have also been reported. In this case series, we present three patients who suffered from SSAH. The first was a spontaneous cervical SSAH that occurred following cardiac catheterization, the second was a spontaneous thoracolumbar SSAH in a patient with a known history of coagulopathy, and the third was a thoracolumbar SSAH that was caused by a dural arteriovenous fistula (dAVF). All three patients exhibited neurologic deficits and thus underwent emergent decompression and hematoma evacuation. The patient with the dAVF also required open ligation of the fistula. Following surgical intervention, all three patients regained at least partial neurologic function, but one patient developed symptomatic arachnoid cysts that required further intervention. The presented case series highlights the importance and time-sensitivity of surgical decompression in patients experiencing neurologic deficits from SSAH. These cases underscore the urgency of timely neurosurgical intervention to mitigate neurologic impairment and add insights to the existing literature on this rare condition.

Pediatric Neurocritical Care.

Brain injury in children is a major public health problem, causing substantial morbidity and mortality. Cause of pediatric brain injury varies widely and can be from a primary neurologic cause or as a sequela of multisystem illness. This review discusses the emerging field of pediatric neurocritical care (PNCC), including current techniques of imaging, treatment, and monitoring. Future directions of PNCC include further expansion of evidence-based practice guidelines and establishment of multidisciplinary PNCC services within institutions.

Narrative Review of Neurologic Complications in Adults on ECMO: Prevalence, Risks, Outcomes, and Prevention Strategies.

Extracorporeal membrane oxygenation (ECMO), a life-saving technique for patients with severe respiratory and cardiac diseases, is being increasingly utilized worldwide, particularly during the coronavirus disease 2019(COVID-19) pandemic, and there has been a sharp increase in the implementation of ECMO. However, due to the presence of various complications, the survival rate of patients undergoing ECMO remains low. Among the complications, the neurologic morbidity significantly associated with venoarterial and venovenous ECMO has received increasing attention. Generally, failure to recognize neurologic injury in time is reportedly associated with poor outcomes in patients on ECMO. Currently, multimodal monitoring is increasingly utilized in patients with devastating neurologic injuries and has been advocated as an important approach for early diagnosis. Here, we highlight the prevalence and outcomes, risk factors, current monitoring technologies, prevention, and treatment of neurologic complications in adult patients on ECMO. We believe that an improved understanding of neurologic complications presumably offers promising therapeutic solutions to prevent and treat neurologic morbidity.

Advances in Anesthesia Monitoring.

During surgery, one of the primary functions of the anesthesiologist is to monitor the patient and ensure safe and effective conduct of anesthesia to provide the optimum operating conditions. Standard guidelines for perioperative monitoring have been firmly established by the American Society of Anesthesiologists. However, in recent years, new advances in technology has led to the development of many new monitoring modalities, especially involving the neurologic and cardiovascular systems. This article presents a targeted review to discuss the functions and limitations of these new monitors and how they are applied in the modern operating room setting.

High-Risk Surgical Maneuvers for Impending True-Positive Intraoperative Neurologic Monitoring Alerts: Experience in 3139 Consecutive Spine Surgeries.

BACKGROUND: Intraoperative neurologic monitoring (IONM) has become an essential component for decreasing the incidence of spinal cord injury during spine surgeries. Many high-risk surgical maneuvers that result in significant IONM alerts have not been reported systematically. Our objective was to thoroughly summarize some common high-risk surgical points associated with IONM alerts in various spine surgeries. METHODS: Between November 2010 and April 2017, 62 patients with true-positive IONM alerts from 3139 spine surgeries were enrolled. Transcranial motor evoked potentials, somatosensory evoked potentials, and free-run electromyography were used for IONM. All 62 patients were identified as true-positive IONM cases. RESULTS: Of 3139 patients, 101 demonstrated significant IONM changes-62 true-positive cases, 14 false-positive cases, and 25 indeterminate IONM results. IONM alerts most often occurred in thoracic screw placement (n = 10, 16.1%), osteotomy (n = 22, 35.5%), correction (n = 19, 30.6%), and spinal cord decompression (n = 11, 17.8%). Appropriate timely measures are indicated in response to IONM alerts during high-risk surgical maneuvers. Ten (10/62, 16.1%) patients showed permanent postoperative neurologic deficits. CONCLUSIONS: IONM alerts are often associated with some specific high-risk surgical maneuvers. Careful and timely observation is crucial.

Neuroprotection Strategies in Aortic Surgery.

Neurologic injury is a potentially devastating complication of aortic surgery. The methods used in aortic surgery, including systemic cooling, initiation of circulatory arrest, and rewarming during the replacement of the aortic arch, are the most complex circulatory management and surgical procedures performed in modern-day surgery. Despite the plethora of published literature, neuroprotection in aortic surgery is largely based on observational studies and institutional-based practices. This article summarizes the current evidence and emerging strategies for neuroprotection in aortic arch operations.