High Versus Low Blood Pressure Targets for Cardiac Surgery with Cardiopulmonary Bypass

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the benefits and harms of a higher versus lower blood pressure target during cardiac surgery with cardiopulmonary bypass (CPB).

In people undergoing cardiac surgery, the optimal blood pressure target is controversial. Several observational studies have suggested an association between blood pressure abnormality and adverse outcomes. Hypotension during cardiac surgery can lead to decreased organ perfusion and is associated with organ dysfunction and mortality after the surgery. On the contrary, excessive hypertension is also associated with postoperative delirium, or may result in excess haemorrhage.

We will create a ‘Summary of findings’ table using the following outcomes (AKI, cognitive deterioration, all‐cause mortality, quality of life, acute ischaemic stroke, length of stay in hospital, and amount of intraoperative haemorrhage). We will use the five GRADE considerations (study limitations, consistency of effect, imprecision, indirectness and publication bias) to assess the certainty of a body of evidence as it relates to the studies which contribute data to the meta‐analyses for the prespecified outcomes. We will use methods and recommendations described in the Cochrane Handbook for Systematic Reviews of Interventions, using the GRADEpro GDT software. We will create only one overall ‘Summary of findings’ table for the comparison of high versus low blood pressure targets for cardiac surgery with CPB. We will justify all decisions to downgrade the certainty of studies using footnotes, and we will make comments to aid reader’s understanding of the review where necessary.

Judgements about evidence certainty will be made by two review authors (SF and TY) working independently, with disagreements resolved by discussion or involving a third review author (YKo or JK or JI or JSWK or YKa). We will justify, document and incorporate judgements into reporting of results for each outcome.

We plan to extract study data, format our comparisons in data tables and prepare a ‘Summary of findings’ table before writing the results and conclusions of our review.