Perioperative Ventilation in Neurosurgical Patients: Considerations and Challenges

Purpose of Review: The aim of this narrative review is to summarize critical considerations for perioperative airway management and mechanical ventilation in patients undergoing neurosurgical procedures. Recent Findings: Given the significant influence that ventilation has on intracranial pressure (ICP) and cerebral blood flow, ventilator settings need to be carefully managed. For example, high positive end-expiratory pressure (PEEP) can increase ICP, while hyperventilation can reduce it. Finding the optimal balance is the key. While evidence supporting lung-protective ventilation in neurosurgical patients is limited, preliminary data suggest that its use could be beneficial, similar to general surgical patients. This typically involves using lower tidal volumes and maintaining optimal oxygenation to prevent ventilator-associated lung injury. Airway management in neurosurgical patients must consider the risk of increased ICP during intubation and the potential for airway complications. Techniques like rapid sequence induction and the use of neuromuscular blockers may be employed to minimize these risks. The primary goal of ventilation in neurosurgical patients is to maintain adequate oxygenation and carbon dioxide removal while minimizing harm to the lungs and brain. However, there may be exceptions where specific ventilatory adjustments are needed, such as in cases of compromised gas exchange or elevated ICP. Summary: Patients undergoing neurosurgical procedures often require invasive ventilation due to the complexities of the operation and the need to manage the airway. This creates unique challenges because ventilator settings must balance the need to protect both the lungs and the brain. Further research is needed to establish clear guidelines and optimize ventilatory care in this population

Utilization of mechanical power and associations with clinical outcomes in brain injured patients: a secondary analysis of the extubation strategies in neuro-intensive care unit patients and associations with outcome (ENIO) trial

Background: There is insufficient evidence to guide ventilatory targets in acute brain injury (ABI). Recent studies have shown associations between mechanical power (MP) and mortality in critical care populations. We aimed to describe MP in ventilated patients with ABI, and evaluate associations between MP and clinical outcomes. Methods: In this preplanned, secondary analysis of a prospective, multi-center, observational cohort study (ENIO, NCT03400904), we included adult patients with ABI (Glasgow Coma Scale ≤ 12 before intubation) who required mechanical ventilation (MV) ≥ 24 h. Using multivariable log binomial regressions, we separately assessed associations between MP on hospital day (HD)1, HD3, HD7 and clinical outcomes: hospital mortality, need for reintubation, tracheostomy placement, and development of acute respiratory distress syndrome (ARDS). Results: We included 1217 patients (mean age 51.2 years [SD 18.1], 66% male, mean body mass index [BMI] 26.3 [SD 5.18]) hospitalized at 62 intensive care units in 18 countries. Hospital mortality was 11% (n = 139), 44% (n = 536) were extubated by HD7 of which 20% (107/536) required reintubation, 28% (n = 340) underwent tracheostomy placement, and 9% (n = 114) developed ARDS. The median MP on HD1, HD3, and HD7 was 11.9 J/min [IQR 9.2-15.1], 13 J/min [IQR 10-17], and 14 J/min [IQR 11-20], respectively. MP was overall higher in patients with ARDS, especially those with higher ARDS severity. After controlling for same-day pressure of arterial oxygen/fraction of inspired oxygen (P/F ratio), BMI, and neurological severity, MP at HD1, HD3, and HD7 was independently associated with hospital mortality, reintubation and tracheostomy placement. The adjusted relative risk (aRR) was greater at higher MP, and strongest for: mortality on HD1 (compared to the HD1 median MP 11.9 J/min, aRR at 17 J/min was 1.22, 95% CI 1.14-1.30) and HD3 (1.38, 95% CI 1.23-1.53), reintubation on HD1 (1.64; 95% CI 1.57-1.72), and tracheostomy on HD7 (1.53; 95%CI 1.18-1.99). MP was associated with the development of moderate-severe ARDS on HD1 (2.07; 95% CI 1.56-2.78) and HD3 (1.76; 95% CI 1.41-2.22). Conclusions: Exposure to high MP during the first week of MV is associated with poor clinical outcomes in ABI, independent of P/F ratio and neurological severity. Potential benefits of optimizing ventilator settings to limit MP warrant further investigation

Optimizing oxygen delivery to the injured brain

The principle of optimizing oxygen delivery to the injured brain rests on the premise that both hypoxia and hyperoxia are important mediators of secondary brain injury and should be avoided. This rationale has prompted a move towards incorporating oxygenation endpoints into the management of neurocritical care patients, particularly those with traumatic brain injury. The present review will seek to describe clinical strategies to optimize oxygenation in the acutely brain-injured patient, drawing upon relevant physiologic principles and clinical data, where it exists

Evaluating the Sum of Eye and Motor Components of the Glasgow Coma Score As a Predictor of Extubation Failure in Patients With Acute Brain Injury

International audienceOBJECTIVES: To evaluate the association between the pre-extubation sum of eye and motor components of the Glasgow Coma Score (GCS-EM) and odds of extubation failure in patients with acute brain injury being liberated from mechanical ventilation. DESIGN: Secondary analysis of a prospective, multicenter observational study (ClinicalTrials.gov identifier NCT03400904). SETTING: Sixty-three hospital sites worldwide, with patient recruitment from January 2018 to November 2020. PATIENTS: One thousand one hundred fifty-two critically ill patients with acute brain injury, with a median age of 54 years, of whom 783 (68.0%) were male, 559 (48.5%) had traumatic brain injury, and 905 (78.6%) had a GCS-EM greater than 8 before extubation (scores range from 2 to 10). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: GCS-EM was computed in intubated patients on the day of extubation. The main outcome was extubation failure, defined as unplanned reintubation within 5 days of extubation. Analyses used multilevel logistic regression with adjustment for patient characteristics and a random intercept for hospital site. In the primary analysis, GCS-EM was not associated with extubation failure (odds ratio, 1.07 per additional point; 95% CI, 0.87–1.31). Findings were consistent in sensitivity analyses that: 1) used different adjustment covariates, 2) included a verbal estimate to derive an overall GCS, 3) accounted for missing data, 4) considered a 2-day time interval to define extubation failure, 5) accounted for competing risks, and 6) used a propensity score-based model. There was no association between GCS-EM and extubation outcome in subgroups defined by brain injury diagnosis or age. CONCLUSIONS: In this large, contemporary, multicenter cohort of patients with acute brain injury, we found no association between the GCS-EM and odds of extubation failure. However, few patients had a pre-extubation GCS-EM less than or equal to 8, and the possibility of a true prognostic association in patients with low scores is not excluded.None

The use of standardized management protocols for critically ill patients with non-traumatic subarachnoid hemorrhage: a protocol of a systematic review and meta-analysis

Abstract Background Caring for patients with subarachnoid hemorrhage (SAH) presents unique challenges, due in part to the severity of the underlying insult, competing systemic injuries, and unpredictable clinical course. Even when management occurs in dedicated critical care settings, treatment uncertainty often persists, and morbidity and mortality from the condition remain high. Complex decisions in SAH care may be simplified with the use of standardized management protocols (SMPs). SMPs incorporate evidence-based guidelines into a practical framework for decision-making, thereby providing clinicians with an algorithm for organizing treatments. But despite these potential advantages, it is currently unknown whether SMPs may improve outcomes in the critical care of patients with SAH. Methods We will conduct a systematic review of cohort studies and randomized control trials of adult patients with non-traumatic SAH who received care according to a standardized management protocol. Comprehensive search strategies will be developed for MEDLINE, EMBASE, WoS, CINAHL, and CENTRAL, to identify studies for review. The gray literature will be scanned for further eligible studies. Two reviewers will independently screen the material generated by the search to identify studies for inclusion. A standardized data extraction form will be used to collect information on study design, baseline characteristics, details of the management protocol employed, and primary and secondary outcomes. Where possible, meta-analyses with random-effects models will be used to calculate pooled estimates of effect sizes. Statistical heterogeneity will be evaluated with the I 2 statistics, and risk of bias and reporting quality will be assessed independently and in duplicate with standardized scales. Discussion We anticipate a significant degree of clinical heterogeneity in our review, as protocols will likely vary in their content, implementation, and ICU setting. We will aim to summarize the current literature in this domain to understand if SMPs, as a low-cost process-targeted intervention, improve outcomes for critically ill patients with SAH. Our review will additionally inform future research endeavors to improve the processes of care for this patient population. Systematic review registration CRD4201706917