Neuroprotective Effect of Low Mean Arterial Pressure on Postoperative Cognitive Deficit Attenuated by Prolonged Coronary Artery Bypass Time: A Meta-Analysis

Abstract

Introduction The true influence of the low mean arterial pressure (low MAP) during coronary artery bypass grafting (CABG) on the development of postoperative cognitive deficit (POCD) remains controversial. We aimed to perform a meta-analysis and meta-regression to determine the effect of low MAP on POCD, as well as moderator variables between low MAP and POCD.Methods The Web of Science, PubMed database, Scopus and the Cochrane Library database (up to June 2018) were searched and retrieved articles systematically reviewed. Only randomized controlled trials (RCTs) comparing maintenance of low MAP (<80 mmHg) and high MAP (>80 mmHg) during cardiopulmonary bypass (CPB) were included in our final review. Statistical analysis of the risk ratio (RR) and corresponding 95% confidence interval (CI) was used to report the overall effect. The overall effect and meta-regression analysis were done using Mantel-Haenszel risk ratio (MHRR) and the corresponding 95% confidence interval (CI).Results A total of 731 patients in three RCTs were included in this study. POCD occurred in 6.4% of all cases. Maintenance of low MAP did not reduce the occurrence of POCD (MHRR 1.012 [95% CI 0.277-3.688]; Z=0.018; P=0.986; I2=66%). Shorter CPB time reduced the occurrence of POCD regardless of group assignment (MH log risk ratio -0.519 [95% CI -0.949 - -0.089]; Z= -2.367; P=0.017).Conclusion POCD is a common event among CABG patients. The neuroprotective effect of low MAP on POCD was attenuated by the prolonged CPB time.

Influence of Anemia on Postoperative Cognitive Function in Patients Undergo Hysteromyoma Surgery

“…The manifestations of POCD range from mild memory loss to the inability to concentrate or process information received by the brain, all of them may have a significant impact on the patient's quality of life. Personal factors such as the patient's educational level, age, gender, preoperative comorbidities, and the presence of preoperative cognitive impairment (Salthouse, 2010;Cao et al, 2014;Wang et al, 2019;Cui et al, 2020;Kiabi et al, 2020), the choice of anesthetic drugs and anesthesia, the mode of surgery, and the length of surgery are all risk factors associated with the development of POCD. In this study, the selected patients have no significant differences in general characteristics, and their anesthesia ASA classification were all ensured to be grade I ∼ II.…”

Contemporary Neuroprotection Strategies during Cardiac Surgery: State of the Art Review

“…Low MAPs are associated with decreased bleeding and thromboembolic phenomena [ 69 ]. In a meta-analysis by Kiabi et al, the neuroprotective effects of low MAP during cardiac surgery were investigated, and the maintenance of MAP below 80 mmHg in this study did not show a decline in the rate of POCD in post-cardiac surgery on CPB [ 10 ]. The current anaesthetic practice supports low MAP in decreasing POCD following cardiac surgery, but the evidence-based threshold has not been determined.…”

An Update on Postoperative Cognitive Dysfunction Following Cardiac Surgery

“…Furthermore, there was no difference in the development of POCD between the high and low MAP target groups [OR = 1.01, 95% CI: (0.33–3.12)]. Kiabi et al ( 96 ) performed a meta-analysis to determine the effect of intraoperative low vs. high MAP on the development of POCD following on-pump CABG. They identified three studies which were not previously examined in this review, including Gold et al ( 97 ), Charlson et al ( 98 ) and Siepe et al ( 99 ).…”

“…From a patient population of 731, the intraoperative maintenance of low MAP did not reduce the incidence of POCD compared to a higher intra-operative MAP (RR = 1.012, 95% CI: [0.277–3.688], p = 0.986). However, it was noted that a shorter cardiopulmonary bypass time was associated with a lower incidence of POCD, regardless of which group the patients were allocated to (RR-logarithmic form = −0.519, 95% CI: [−0.949, −0.089], p = 0.017) ( 96 ). These results suggest that perhaps the longer bypass time did potential benefits of a low intraoperative MAP on post-operative cognitive function to be observed.…”