Incidence of Postoperative Cognitive Dysfunction Following Inhalational vs Total Intravenous General Anesthesia: A Systematic Review and Meta-Analysis

Abstract

Postoperative cognitive dysfunction (POCD) has been increasingly recognized as a contributor to postoperative complications. A consensus-working group recommended that POCD should be distinguished between delayed cognitive recovery, ie, evaluations up to 30 days postoperative, and neurocognitive disorder, ie, assessments performed between 30 days and 12 months after surgery. Additionally, the choice of the anesthetic, either inhalational or total intravenous anesthesia (TIVA) and its effect on the incidence of POCD, has become a focus of research. Our primary objective was to search the literature and conduct a meta-analysis to verify whether the choice of general anesthesia may impact the incidence of POCD in the first 30 days postoperatively. As a secondary objective, a systematic review of the literature was conducted to estimate the effects of the anesthetic on POCD between 30 days and 12 months postoperative. For the primary objective, an initial review of 1913 articles yielded ten studies with a total of 3390 individuals. For the secondary objective, four studies with a total of 480 patients were selected. In the first 30 days postoperative, the odds-ratio for POCD in TIVA group was 0.46 (95% CI = 0.26-0.81; p = 0.01), compared to the inhalational group. TIVA was associated with a lower incidence of POCD in the first 30 days postoperatively. Regarding the secondary objective, due to the small number of selected articles and its high heterogeneity, a metanalysis was not conducted. Given the heterogeneity of criteria for POCD, future prospective studies with more robust designs should be performed to fully address this question.

Keywords: POCD; TIVA; inhalational anesthesia; postoperative cognitive dysfunction; postoperative complications; psychometric tests; total intravenous anesthesia.

Figure 1

The complete search strategy.

Figure 2

PRISMA^® flow chart showing article selection process.

Figure 3

Forest plot presented OR, for each of the ten studies included for primary objective, and pooled data (TIVA vs Inhalational).

Figure 4

Forest plot presented OR, for each of the nine studies included for primary objective, excluding “Cai et al”, and pooled data (TIVA vs Inhalational).

Figure 5

Cochrane collaboration’s tool for assessing risk of bias for the included studies.

Figure 6

Application of the GRADE system to our findings. We believe our evidence should be classified as moderate.