Synergistic effect of sarcopenia and ASA status in predicting mortality after emergency laparotomy: a systematic review and meta-analysis with meta-regression.

The aim of this study was to investigate the relationship between sarcopenia and American Society of Anesthesiologists (ASA) status in predicting post-operative mortality after emergency laparotomy. A PRISMA-compliant systematic review and meta-analysis (using random effects modelling) was performed searching for studies reporting 30-day mortality risk in patients with sarcopenia undergoing emergency laparotomy. The ASA status of sarcopenic and non-sarcopenic patients was determined, and the effect of difference in ASA status on 30-day mortality in sarcopenic and non-sarcopenic patients was determined via a meta-regression model. The risk of bias and certainty was assessed using the QUIPS tool and the GRADE system, respectively. Seven studies comprising 2663 patients were included. Thirty-day mortality risk was 22.9% (95% CI 11.6-40.0%) in sarcopenic patients and 6.2% (95% CI 2.9-13.0%) in non-sarcopenic patients; the risk was significantly higher in sarcopenic patients (OR: 4.452, p = 0.016). In sarcopenic patients, ASA status IV-V increased the risk of mortality (Coefficient: 0.07612, p < 0.0001), while ASA status I-II (Coefficient: - 0.09039, p < 0.0001) or ASA status III (Coefficient: 0.01300, p = 0.344) did not. In non-sarcopenic patients, ASA status III (Coefficient: 0.06830, p < 0.0001) and ASA status IV-V (Coefficient: 0.17809, p < 0.0001) increased the risk of mortality, while ASA status I-II (Coefficient: - 0.05841, p < 0.0001) did not. The GRADE certainty was moderate. Sarcopenia and ASA status are two independent predictors of mortality after emergency laparotomy with no significant collinearity. Sarcopenia and ASA status synergistically increase the risk of mortality after emergency laparotomy. ASA status IV and ASA status III are critical thresholds for increased risk of mortality in sarcopenic and non-sarcopenic patients, respectively.