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 the control group <۱۰%, 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 Rev Man, version ۵.۳.۵, Cochrane Collaboration, Oxford, England, UK) were used to combine studies using odds ratios (ORs) and ۹۵% confidence intervals (CIs).
Results: In ۴۷ RCTs, ۲۳۲۹ patients developed at least one complication: ۱۰۳۰ out of ۲۷۸۱ (۳۷%) were randomized to perioperative GDT, and ۱۲۹۹ out of ۲۷۷۲ (۴۷%) were randomized to control. Pooled OR was ۰.۵۸ and ۹۵% CI was ۰.۴۷-۰.۷۰. The sensitivity analysis confirmed the main result. The subgroup analysis including only studies in which the mortality rate in the control group was higher than ۱۰% showed significant results (OR ۰.۵۱, ۹۵% CI ۰.۳۵-۰.۷۴, p=۰.۰۰۴, ۱۰ RCTs), as well as a statistical significant effect, was observed in those RCTs with a mortality rate in control group <۱۰% (OR ۰.۵۹, ۹۵% CI ۰.۴۷-۰.۷۴, p<۰.۰۰۰۱, ۳۷ RCTs). The subgroup analysis enrolling major abdominal patients showed a significant result (OR ۰.۶۹, ۹۵% CI ۰.۵۷-۰.۸۳,p <۰.۰۰۰۱, ۲۹ RCTs, ۳۸۸۱ patients) as well as a significant effect was observed in those RCTs enrolling exclusively orthopedic (OR ۰.۴۸, ۹۵% CI ۰.۳۰-۰.۷۹,p=۰.۰۰۴, ۶ RCTs, ۵۰۱ patients) and neurosurgical procedures (OR ۰.۴۰, ۹۵% CI ۰.۲۱-۰.۷۸, p=۰.۰۰۸, ۲ RCTs, ۲۰۸ patients).
Conclusions: The present meta-analysis suggests that GDT can reduce postoperative complication rates 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 patients and in different kinds of surgeries.