Haemodynamic goal-directed therapy in cardiac and vascular surgery. A systematic review and meta-analysis

Abstract

In cardiovascular surgery, reduced organ perfusion and oxygen delivery contribute to increased postoperative morbidity and prolonged intensive care unit stay. Goal-directed therapy (GDT), a perioperative haemodynamic strategy aiming to increase cardiac output, is helpful in preventing postoperative complications, but studies in the context of cardiovascular surgery have produced conflicting results. The purpose of the present meta-analysis is to determine the effects of perioperative haemodynamic goal-directed therapy on mortality and morbidity in cardiac and vascular surgery. MEDLINE, EMBASE, The Cochrane Library and the DARE databases were searched until July 2011. Randomized controlled trials reporting on adult cardiac or vascular surgical patients managed with perioperative GDT or according to routine haemodynamic practice were included. Primary outcome measures were mortality and morbidity. Data synthesis was obtained by using odds ratio (OR) with 95% confidence interval (CI) by a random effects model. An OR <1 favoured GDT. Statistical heterogeneity was assessed by Q and I(2) statistics. Eleven articles (five cardiac surgery and six vascular procedures), enrolling a total sample of 1179 patients, were included in the analysis. As compared with routine haemodynamic practice, perioperative GDT did not reduce mortality in either cardiac or vascular surgery (pooled OR 0.87; 95% CI 0.37-2.02; statistical power 64%). GDT significantly reduced the number of cardiac patients with complications (OR 0.34; 95% CI 0.18-0.63; P = 0.0006), but no effect was observed in vascular patients (OR, 0.84; 95% CI 0.45-1.56; P = 0.58). Perioperative GDT prevents postoperative complications in cardiac surgery patients, while it has no effect in vascular surgery. The different characteristics and comorbidities of the population enrolled could explain these conflicting results. More trials conforming to the characteristics of low-risk-of-bias studies and enrolling a larger and well-defined population of patients are needed to better clarify the effect of GDT in the specific setting of cardiovascular surgery.

Figures

Figure 1:

Outline of studies selection process. Flow chart summarizing the procedure of studies selection for the meta-analysis.

Figure 2:

Mortality. Rates of postoperative mortality for each of the studies with ORs and 95% Cl. The studies were divided into two sub-groups defined as cardiac and vascular surgery. The pooled OR and 95% CI are shown as the total. The size of the box at the point estimate of the OR gives a visual representation of the ‘weighting’ of the study. The diamond represents the point estimate of the pooled OR and the length of the diamond is proportional to the CI. OR: odds ratios; 95% CI: 95% confidence intervals.

Figure 3:

Patients with postoperative complications. Rates of patients with postoperative complications for each of the studies with ORs and 95% Cl. The studies were divided into two sub-groups defined as cardiac and vascular surgery. The pooled OR and 95% CI are shown as the total. The size of the box at the point estimate of the OR gives a visual representation of the ‘weighting’ of the study. The diamond represents the point estimate of the pooled OR and the length of the diamond is proportional to the CI. OR: odds ratios; 95% CI: 95% confidence intervals.

Figure 4:

Postoperative complications in vascular surgery. Rates of postoperative complications for each of the studies involving vascular surgery with ORs and 95% Cl. The studies were divided into two sub-groups defined as cardiac and non-cardiac complications (see text for details). The pooled OR and 95% CI are shown as the total. The size of the box at the point estimate of the OR gives a visual representation of the ‘weighting’ of the study. The diamond represents the point estimate of the pooled OR and the length of the diamond is proportional to the CI. OR: odds ratios; 95% CI: 95% confidence intervals.

Figure 5:

Postoperative complications in cardiac surgery. Rates of postoperative complications for each of the studies involving cardiac surgery with ORs and 95% Cl. The studies were divided into two sub-groups defined as cardiac and non-cardiac complications (see text for details). The pooled OR and 95% CI are shown as the total. The size of the box at the point estimate of the OR gives a visual representation of the ‘weighting’ of the study. The diamond represents the point estimate of the pooled OR and the length of the diamond is proportional to the CI. OR: odds ratios; 95% CI: 95% confidence intervals.