Is perioperative goal-directed therapy able to reduce surgical complications in different surgical settings? A meta-analytic study

Introduction: Goal directed therapy (GDT) is a method aiming at optimizing doses and timing of fluids, inotropes and vasopressors, through monitoring of cardiac output and other basic hemodynamic parameters. Several meta-analyses confirm that GDT can reduce postoperative complications in high risk patients, and a recent trial suggests its significant effect also in low-moderate risk patients. The aim of the present meta-analysis is to investigate the effect of GDT on postoperative complications, in both high and low risk patients. Moreover, we stratified the effect of GDT in different kind of surgical procedures. Methods: Randomized controlled trials (RCTs) on perioperative GDT in adult surgical patients were included. The primary outcome measure was complications, defined as number of patients with a least one postoperative complication. A subgroup- analysis was also performed including RCTs with a mortality rate in control group <10%, and considering the kind of surgery: major abdominal (including also major vascular), only vascular, only orthopedic surgery and so on. Meta-analytic techniques (analysis software RevMan, version 5.3.5, Cochrane Collaboration, Oxford, England, UK) were used to combine studies using odds ratios (ORs) and 95% confidence intervals (CIs). Results: In 47 RCTs, 2329 patients developed at least one complication: 1030 out of 2781 (37%) were randomized to perioperative GDT, and 1299 out of 2772 (47%) were randomized to control. Pooled OR was 0.58 and 95% CI was 0.47-0.70. The sensitivity analysis confirmed main result. The subgroup analysis including only studies in which the mortality rate in the control group was higher than 10% showed significant results (OR 0.51, 95% CI 0.35-0.74, p=0.004, 10 RCTs), as well as a statistical significant effect was observed in those RCTs with a mortality rate in control group <10% (OR 0.59, 95% CI 0.47-0.74, p<0.0001, 37 RCTs). The subgroup analysis enrolling major abdominal patients showed a significant result (OR 0.69, 95% CI 0.57- 0.83,p <0.0001, 29 RCTs, 3881 patients) as well as a significant effect was observed in those RCTs enrolling exclusively orthopedic (OR 0.48, 95% CI 0.30-0.79,p=0.004, 6 RCTs, 501 patients) and neurosurgical procedures (OR 0.40, 95% CI 0.21-0.78, p=0.008, 2 RCTs, 208 patients). Conclusions: The present meta-analysis suggests that GDT can reduce postoperative complication rate in high risk as well as in low risk patients. Moreover, the beneficial effect of GDT on postoperative morbidity is significant on major abdominal, orthopedic and neurosurgical procedures. However, heterogeneity was found in some subgroups, reducing the strength of the results. Several well-designed RCTs are needed to further explore the effect of GDT in low risk patient and in different kind of surgeries.