Pour ou contre les halogénés en neuroanesthésie pour chirurgie intracrânienne

Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

BACKGROUND

Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques.

METHODS

Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI].

RESULTS

We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1-3], 8% [95%CI:6-11], 17% [95%CI:12-23] and 2% [95%CI:2-3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36-2.69], 1.01 [95%CI:0.52-1.88] for seizures, 1.66 [95%CI:1.35-3.70] for new neurological dysfunction and 2.17 [95%CI:1.22-3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was abolished in a sensitivity analysis of only prospectively conducted studies.

CONCLUSION

SAS and MAC techniques were feasible and safe, whereas data for AAA technique are limited. Large RCTs are required to prove superiority of one anaesthetic regime for AC.

Safety and efficacy of combined epidural/general anesthesia during major abdominal surgery in patients with increased intracranial pressure: a cohort study

Background

The increased intracranial pressure can significantly complicate the perioperative period in major abdominal surgery, increasing the risk of complications, the length of recovery from the surgery, worsening the outcome. Epidural anesthesia has become a routine component of abdominal surgery, but its use in patients with increased intracranial pressure remains controversial. The goal of the study was to evaluate the safety and efficacy of epidural anesthesia, according to monitoring of intracranial pressure in patients with increased intracranial pressure.

Methods

The study includes 65 surgical patients who were routinely undergone the major abdominal surgery under combined epidural/general anesthesia. Depending on the initial ICP all patients were divided into 2 groups: 1 (N group) - patients with the normal intracranial pressure (≤12 mm Hg, n = 35) and 2 (E group) – patients with the elevated intracranial pressure (ICP > 12 mm Hg, n = 30). During the surgery we evaluated ICP, blood pressure, cerebral perfusion pressure (CPP). The parameters of recovery from anesthesia and the effectiveness of postoperative analgesia were also assessed.

Results

In N group ICP remained stable. In E group ICP decreased during anesthesia, the overall decline was 40 % at the end of the operation (from 15 to 9 mm Hg (P <0.05)). The correction of MAP with vasopressors to maintain normal CPP was required mainly in patients with increased ICP (70 % vs. 45 %, p <0.05). CPP declined by 19 % in N group. In E group the CPP reduction was 23 %, and then it remained stable at 60 mm Hg. No significant differences in time of the recovery of consciousness, effectiveness of postoperative analgesia and complications between patients with initially normal levels of ICP and patients with ICH were noted.

Conclusions

The combination of general and epidural anesthesia is safe and effective in patients with increased intracranial pressure undergoing elective abdominal surgery under the condition of maintaining the arterial pressure. Its use is not associated with the increase in intracranial pressure during the anesthesia, but it needs an intraoperative monitoring of ICP in order to prevent CPP reduction.

Intraoperative blood pressure and cerebral perfusion: strategies to clarify hemodynamic goals

Blood pressure can vary considerably during anesthesia. If blood pressure falls outside the limits of cerebrovascular autoregulation, children can become at risk of cerebral ischemic or hyperemic injury. However, the blood pressure limits of autoregulation are unclear in infants and children, and these limits can shift after brain injury. This article will review autoregulation, considerations for the hemodynamic management of children with brain injuries, and research on autoregulation monitoring techniques.

Comparison of propofol and volatile agents for maintenance of anesthesia during elective craniotomy procedures: systematic review and meta-analysis

BACKGROUND

Both propofol and volatile anesthetics are commonly used for maintenance of anesthesia in patients undergoing neurosurgical procedures. The effects of these two classes of drugs on cerebral hemodynamics have been compared in many clinical trials The objectives of this review were to evaluate the cerebral hemodynamic effects, operative conditions, recovery profiles, postoperative complications, and neurological outcomes of propofol-based vs volatile-based anesthesia for craniotomy.

METHODS

MEDLINE®, EMBASE™, Cochrane, and other relevant databases were searched for randomized controlled trials that compared propofol-maintained anesthesia with volatile-maintained anesthesia in adult patients undergoing elective craniotomy. The primary outcome measure was the intraoperative brain relaxation score. Secondary outcome measures included intraoperative cerebral hemodynamics (intracranial pressure [ICP], cerebral perfusion pressure [CPP]), cardiovascular changes, recovery profiles, postoperative complications, and clinical outcomes (neurological morbidity, mortality, quality of life). A meta-analysis was conducted using a random effects model to compare the outcomes of the two anesthetic techniques.

RESULTS

Fourteen studies (1,819 patients) met inclusion criteria and were analyzed. Brain relaxation scores were similar between the two groups after dural opening; however, ICP was lower (weighted mean difference of -5.2 mmHg; 95% confidence interval -6.81 to -3.6) and CPP was higher (weighted mean difference of 16.3 mmHg; 95% confidence interval 12.2 to 20.46) in patients receiving propofol-maintained anesthesia. Postoperative complications and recovery profiles were similar between the two groups, except for postoperative nausea and vomiting being less frequent with propofol-maintained anesthesia. There were inadequate data to perform a meta-analysis on clinical outcome.

CONCLUSION

Propofol-maintained and volatile-maintained anesthesia were associated with similar brain relaxation scores, although mean ICP values were lower and CPP values higher with propofol-maintained anesthesia. There are inadequate data to compare clinically significant outcomes such as neurological morbidity or mortality.