Brain tissue oxygen combined with intracranial pressure monitoring versus isolated intracranial pressure monitoring in patients with traumatic brain injury: an updated systematic review and meta-analysis

Brain Tissue Oxygen Combined with Intracranial Pressure Monitoring in Patients with Severe Traumatic Brain Injury: An Updated Systematic Review and Pooled Analysis Following the OXY-TC Trial

BACKGROUND

Severe traumatic brain injury (TBI) is associated with high mortality and long-term disability. Effective TBI management, aimed at minimizing secondary brain damage, requires constant monitoring of intracranial pressure (ICP) with or without brain tissue oxygen pressure (PbtO2). The recent OXY-TC trial suggested that combined ICP + PbtO2 monitoring does not improve the 6-month neurological outcomes, prompting a meta-analysis to reassess the clinical role of PbtO2 monitoring.

METHODS

We conducted a systematic review and meta-analysis by searching the PubMed, Medline, and Cochrane databases for randomized controlled trials and prospective studies on adult severe TBI patients, comparing clinical outcomes of ICP monitoring alone versus ICP + PbtO2 monitoring. Data extraction and quality assessments were performed independently by two reviewers. Meta-analyses were conducted using a random-effects model, focusing on 6-month mortality and favorable functional outcomes.

RESULTS

Six studies met the inclusion criteria. The ICP + PbtO2 group is more likely to have favorable outcomes (odds ratio: 1.39, 95% confidence interval: 1.01-1.92, I2 = 0%) 6 months following TBI. There were no statistically significant differences in the 6-month mortality (odds ratio: 0.75, 95% confidence interval: 0.52-1.10; I2 = 0%).

CONCLUSIONS

Our research findings partially align with the OXY-TC trial regarding the primary endpoint, demonstrating that brain tissue oxygen-guided therapy does not significantly reduce mortality rates in TBI patients 6 months postinjury. However, in contrast to the OXY-TC trial, we observed that the PbtO2 monitoring group showed a significantly higher proportion of favorable outcomes.

Brain tissue oxygen pressure combined with intracranial pressure monitoring may improve clinical outcomes for patients with severe traumatic brain injury: a systemic review and meta-analysis

Background

Although the optimization of brain oxygenation is thought to improve the prognosis, the effect of brain tissue oxygen pressure (PbtO2) for patients with severe traumatic brain injury (STBI) remains controversial. Therefore, the present study aimed to determine whether adding PbtO2 to intracranial pressure (ICP) monitoring improves clinical outcomes for patients with STBI.

Methods

PubMed, Embase, Scopus and Cochrane Library were searched for eligible trials from their respective inception through April 10th, 2024. We included clinical trials contrasting the combined monitoring of PbtO2 and ICP versus isolated ICP monitoring among patients with STBI. The primary outcome was favorable neurological outcome at 6 months, and secondary outcomes including the in-hospital mortality, long-term mortality, length of stay in intensive care unit (ICU) and hospital.

Results

A total of 16 studies (four randomized studies and 12 cohort studies) were included in the meta-analysis. Compared with isolated ICP monitoring, the combined monitoring was associated with a higher favorable neurological outcome rate at 6 months (RR 1.33, 95% CI [1.17-1.51], P < 0.0001, I2 = 0%), reduced long-term mortality (RR 0.72, 95% CI [0.59-0.87], P = 0.0008, I2 = 2%). No significant difference was identified in the in-hospital mortality (RR 0.81, 95% CI 0.66 to 1.01, P = 0.06, I2 = 32%), length of stay in ICU (MD 2.10, 95% CI [-0.37-4.56], P = 0.10, I2 = 78%) and hospital (MD 1.07, 95% CI [-2.54-4.67], P = 0.56, I2 = 49%) between two groups. However, the pooled results of randomized studies did not show beneficial effect of combined monitoring in favorable neurological outcome and long-term mortality.

Conclusions

Currently, there is limited evidence to prove that the combined PbtO2 and ICP monitoring may contribute to improved neurological outcome and long-term mortality for patients with STBI. However, the benefit of combined monitoring should be further validated in more randomized studies.

Anesthesia for traumatic brain injury

PURPOSE OF REVIEW

Traumatic brain injury (TBI) presents complex clinical challenges, requiring a nuanced understanding of its pathophysiology and current management principles to improve patient outcomes. Anesthetists play a critical role in care and need to stay updated with recent evidence and trends to ensure high-quality treatment. The Brain Trauma Foundation Guidelines, last updated in 2016, have shown moderate adherence, and much of the current management relies on expert opinions. This literature review synthesizes the current evidence and provides insights into the role of anesthetists in TBI management.

RECENT FINDINGS

Recent literature has emphasized the importance of tailored anesthetic management principles in treating TBI, focusing on minimizing secondary brain injury during neurosurgical interventions or extracranial surgery. Emerging trends include individualized intracranial pressure approaches and multimodal neuromonitoring for comprehensive assessment of cerebral physiology.

SUMMARY

Anesthesia for TBI patients requires a comprehensive approach that balances anesthetic goals with the unique pathophysiological factors of brain injury. Despite recent research expanding our understanding, challenges remain in standardizing protocols and addressing individual patient response variability. Adherence to established management principles, personalized approaches, and ongoing research is crucial for improving the outcomes.

Brain tissue oxygen plus intracranial pressure monitoring versus isolated intracranial pressure monitoring in patients with traumatic brain injury: an updated meta-analysis of randomized controlled trials

BACKGROUND

Intracranial pressure (ICP) monitoring plays a key role in patients with traumatic brain injury (TBI), however, cerebral hypoxia can occur without intracranial hypertension. Aiming to improve neuroprotection in these patients, a possible alternative is the association of Brain Tissue Oxygen Pressure (PbtO2) monitoring, used to detect PbtO2 tension.

METHOD

We systematically searched PubMed, Embase and Cochrane Central for RCTs comparing combined PbtO2 + ICP monitoring with ICP monitoring alone in patients with severe or moderate TBI. The outcomes analyzed were mortality at 6 months, favorable outcome (GOS ≥ 4 or GOSE ≥ 5) at 6 months, pulmonary events, cardiovascular events and sepsis rate.

RESULTS

We included 4 RCTs in the analysis, totaling 505 patients. Combined PbtO2 + ICP monitoring was used in 241 (47.72%) patients. There was no significant difference between the groups in relation to favorable outcome at 6 months (RR 1.17; 95% CI 0.95-1.43; p = 0.134; I2 = 0%), mortality at 6 months (RR 0.82; 95% CI 0.57-1.18; p = 0.281; I2 = 34%), cardiovascular events (RR 1.75; 95% CI 0.86-3.52; p = 0.120; I2 = 0%) or sepsis (RR 0.75; 95% CI 0.25-2.22; p = 0.604; I2 = 0%). The risk of pulmonary events was significantly higher in the group with combined PbtO2 + ICP monitoring (RR 1.44; 95% CI 1.11-1.87; p = 0.006; I2 = 0%).

CONCLUSIONS

Our findings suggest that combined PbtO2 + ICP monitoring does not change outcomes such as mortality, functional recovery, cardiovascular events or sepsis. Furthermore, we found a higher risk of pulmonary events in patients undergoing combined monitoring.