The correlation of intraoperative hypotension and postoperative cognitive impairment: a meta-analysis of randomized controlled trials

Xiaojin Feng,Fuzhou Hua,Guohai Xu,Lieliang Zhang,Jing Zhang,Jialing Hu

doi:10.1186/s12871-020-01097-5

Abstract

BackgroundThere is no consensus on whether intraoperative hypotension is associated with postoperative cognitive impairment. Hence, we performed a meta-analysis to evaluate the correlation of intraoperative hypotension and the incidence of postoperative delirium (POD) or postoperative cognitive dysfunction (POCD).MethodsWe searched PubMed, Embase, and Cochrane Library databases to find randomized controlled trials (RCTs) in which reported the relationship between intraoperative hypotension and POD or POCD. The retrieval time is up to January 2020, without language restrictions. Quality assessment of the eligible studies was conducted by two researchers independently with the Cochrane evaluation system.ResultsWe analyzed five eligible RCTs. Based on the relative mean arterial pressure (MAP), participants were divided into low-target and high-target groups. For the incidence of POD, there were two studies with 99 participants in the low-target group and 94 participants in the high-target pressure group. For the incidence of POCD, there were four studies involved 360 participants in the low-target group and 341 participants in the high-target group, with a study assessed both POD and POCD. No significant difference between the low-target and the high-target group was observed in the incidence of POD (RR = 3.30, 95% CI 0.80 to 13.54, P = 0.10), or POCD (RR = 1.26, 95% CI 0.76 to 2.08, P = 0.37). Furthermore, it also demonstrates that intraoperative hypotension prolonged the length of ICU stay, but did not increased the mortality, the length of hospital stay, and mechanical ventilation (MV) time.ConclusionsThere is no significant correlation between intraoperative hypotension and the incidence of POD or POCD.

Highlights

There is no consensus on whether intraoperative hypotension is associated with postoperative cognitive impairment
The assessment methods of cognitive function were different, including neuropsychologic battery tests, Minimental state examination (MMSE) scores, International Study of Postoperative Cognitive Dysfunction (ISPOCD), and the Confusion Assessment Method adapted for the ICU (CAM-ICU) scale
Given the fact that the incidence of postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) were our primary outcomes, studies that did not contain POD or POCD data were excluded; the application of our secondary outcomes may be limited. The results of this meta-analysis should be further confirmed by much more high-quality studies. To our knowledge, this meta-analysis is the first systematic review to analyze the correlation of intraoperative hypotension and postoperative cognitive impairment, which provides a comprehensive summary of all currently available data on this crucial issue

Summary

Introduction

There is no consensus on whether intraoperative hypotension is associated with postoperative cognitive impairment. We performed a meta-analysis to evaluate the correlation of intraoperative hypotension and the incidence of postoperative delirium (POD) or postoperative cognitive dysfunction (POCD). Postoperative cognitive impairment, including postoperative delirium (POD) and postoperative cognitive dysfunction (POCD), is a common neuropsychological disorder after surgery among patients [1]. The underlying pathophysiology of POD or POCD is multifactor and complicated. Immutable risk factors, such as surgery types, age and baseline cognitive function have been identified [5, 7]. The definitive preventive or therapeutic measure of POD or POCD is still unknown, there are increasing studies shows that hypoperfusion of the brain caused by hypotension during the surgery may be one pathogenic mechanism [9,10,11,12]

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Discussion

Conclusion