Hemodynamic Impact of the Trendelenburg Position: A Systematic Review and Meta-analysis.

Objective: To systematically evaluate the impact of the Trendelenburg position on hemodynamic parameters in adult patients.

Design: Systematic literature review and meta-analysis using PubMed and Medline.

Setting: All prospective interventional studies comparing the hemodynamic characteristics of patients in the horizontal supine position and Trendelenburg position.

Measurements and main results: A total of 16 studies including 333 patients were found. The Trendelenburg position led to a statistically significant 11% increase in stroke volume compared with the supine position (mean difference [MD] = 8.27, 95% confidence interval [CI]: 1.79; 14.76, p = 0.012). A decrease in stroke volume variation (MD = -1.36, 95% CI: 2.26; -0.46, p = 0.003) and heart rate (MD = -1.65, 95% CI: -2.86; -0.44, p = 0.008) and an increase in cardiac output (MD = 0.33, 95% CI: 0.1; 0.57, p = 0.006), mean arterial pressure (standardized MD, = 0.42, 95% CI: 0.1; 0.74, p = 0.011), central venous pressure (MD = 4.13, 95% CI: 2.42; 5.84, p < 0.001), mean pulmonary artery pressure (MD = 4.25, 95% CI: 2.69; 5.81, p < 0.001), and left ventricular end-diastolic volume (MD = 16.89, 95% CI: 3.17; 30.61, p = 0.016) were found.

Conclusions: The Trendelenburg position significantly increases stroke volume and improves multiple hemodynamic parameters in adult patients. These results confirm the position's potential clinical relevance in hemodynamic management and suggest the possibility of a tailored application in selected clinical settings. The duration of the beneficial effects of the Trendelenburg position and the possible side effects should be the focus of further investigation.