Author information

¹Department of Emergency Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada. k.rikhraj@alumni.ubc.ca.

²Department of Emergency Medicine, Vancouver General Hospital, 899 West 12th Avenue, Vancouver, BC, V5Z 1M9, Canada. k.rikhraj@alumni.ubc.ca.

³Department of Emergency Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.

⁴Division of Critical Care Medicine, Department of Medicine, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.

⁵Department of Anesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, The University of British Columbia, Vancouver, BC, Canada.

⁶Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada.

Abstract

Purpose: Targeted blood pressure thresholds remain unclear in critically ill patients. Two prior systematic reviews have not shown differences in mortality with a high mean arterial pressure (MAP) threshold, but there have been new studies published since. Thus, we conducted an updated systematic review and meta-analysis of randomized controlled trials (RCTs) that compared the effect of a high-normal vs low-normal MAP on mortality, favourable neurologic outcome, need for renal replacement therapy, and adverse vasopressor-induced events in critically ill patients.

Source: We searched six databases from inception until 1 October 2022 for RCTs of critically ill patients targeted to either a high-normal vs a low-normal MAP threshold for at least 24 hr. We assessed study quality using the revised Cochrane risk-of-bias 2 tool and the risk ratio (RR) was used as the summary measure of association. We used the Grading of Recommendations Assessment, Development, and Evaluation framework to assess the certainty of evidence.

Principal findings: We included eight RCTs with 4,561 patients. Four trials were conducted in patients following out-of-hospital cardiac arrest, two in patients with distributive shock requiring vasopressors, one in patients with septic shock, and one in patients with hepatorenal syndrome. The pooled RRs for mortality (eight RCTs; 4,439 patients) and favourable neurologic outcome (four RCTs; 1,065 patients) were 1.06 (95% confidence interval [CI], 0.99 to 1.14; moderate certainty) and 0.99 (95% CI, 0.90 to 1.08; moderate certainty), respectively. The RR for the need for renal replacement therapy (four RCTs; 4,071 patients) was 0.97 (95% CI, 0.87 to 1.08; moderate certainty). There was no statistical between-study heterogeneity across all outcomes.

Conclusion: This updated systematic review and meta-analysis of RCTs found no differences in mortality, favourable neurologic outcome, or the need for renal replacement therapy between critically ill patients assigned to a high-normal vs low-normal MAP target.

Study registration: PROSPERO (CRD42022307601); registered 28 February 2022.