Effect of volatile anaesthetic agents on intracranial pressure, cerebrovascular flow and autoregulation: a protocol for a systematic review and meta-analysis.

INTRODUCTION

The use of volatile anaesthetic agents for the sedation of patients requiring critical care treatment offers several theoretical advantages over intravenous sedation, which may be of benefit in neurocritical care. However, there are concerns that they may increase intracranial pressure. The objective of this systematic review is to assess whether, and if so, to what extent volatile anaesthetic agents affect intracranial pressure, cerebral blood flow (CBF), cerebral oximetry and cerebrovascular autoregulation. If sufficient data exist, subgroup analyses will be conducted in traumatic brain injury and decompressive craniectomy patients.

METHODS AND ANALYSIS: A database search of PubMed, Medline (including Medline plus), CINAHL (including CINAHL Plus), Embase databases and the Cochrane Central Controlled Trials Register without time limits will be conducted. The search results will be screened by title and abstract by two independent researchers on a rule-in basis against predetermined criteria-controlled studies in humans of contemporary fluorinated volatile anaesthetic agents against a control, which measures intracranial pressure, CBF, cerebral oximetry or cerebrovascular autoregulation. Articles responsive to screening will then be reviewed in full text by two independent researchers, requiring consensus or a tie-break by a third independent researcher. Reference lists and a non-generative AI tool will be examined for missed articles, with all identified articles being reviewed in full text by two independent researchers. The included articles will be assessed for risk of bias and will have data extracted by two independent researchers. If sufficient data exist, a meta-analysis will be performed; otherwise, a narrative description of outcomes will be performed.

ETHICS AND DISSEMINATION: No ethics approval will be sought for this systematic review. This study has no explicit funding. The results of this study will be disseminated in a peer-reviewed journal, in a conference presentation and on PROSPERO.

TRIAL REGISTRATION NUMBER: PROSPERO number CRD42023474587.