Sublingual microcirculatory alterations during the immediate and early postoperative period: A systematic review and meta-analysis

Study objectiveTo systematically review the literature regarding the presence of sublingual microcirculatory alterations during the immediate and early postoperative period. DesignSystematic review and meta-analysis searching PubMed, Scopus, and Google Scholar. Patients/interventionsStudies comparing sublingual microcirculation before and after surgery. MeasurementThe primary outcome was to investigate the severity of microcirculatory alterations during the immediate and early postoperative period in adult patients undergoing non-cardiac and cardiac surgery. Main resultsAmong 17 eligible studies, 13 were finally analyzed. A non-statistically significant difference was found between preoperative and postoperative total vessel density (p=0.084; estimate: -0.029; 95% CI: -0.31 to 0.26; I2 = 22.55%, Q = 10.23, p=0.24). Perfused vessel density significantly decreased postoperatively (p=0.035; estimate: 0.344; 95% CI: 0.02 to 0.66; I2 = 65.66%, Q = 41.77, p<0.001), while perfused boundary region significantly increased postoperatively (p=0.031; estimate: -0.415; 95% CI: -0.79 to -0.03; I2 = 37.21%, Q = 6.56, p=0.16). Microvascular flow index significantly decreased postoperatively (p=0.028; estimate: 0. 587; 95% CI: 0.06 to 1.11; I2 = 86.09%, Q = 96.28, p<0.001), while a non-statistically significant difference was found between preoperative and postoperative proportion of perfused vessels (p=0.089; estimate: 0.53; 95% CI: -0.08 to 1.14; I2 = 70.71%, Q = 18.99, p=0.002). The results in the non-cardiac surgery subgroup were comparable with the full group except that a statistically non-significant difference in PVD was found in the remaining seven studies (p=0.19; estimate: 0.26; 95% CI: -0.13 to 0.66; I2 = 71.94%, Q = 33.42, p=0.002). The other parameters did not differ significantly from their respective full group results. ConclusionsSignificant sublingual microcirculatory alterations are present during the immediate and early postoperative period.