Meta-analysis of hemodynamic optimization: relationship to methodological quality

Introduction To review systematically the effect of interventions aimed at hemodynamic optimization and to relate this to the quality of individual published trials. Methods A systematic, computerized bibliographic search of published studies and citation reviews of relevant studies was performed. All randomized clinical trials in which adult patients were included in a trial deliberately aiming at an optimized or maximized hemodynamic condition of the patients ( with oxygen delivery, cardiac index, oxygen consumption, mixed venous oxygen saturation and/or stroke volume as end-points) were selected. A total of 30 studies were selected for independent review. Two reviewers extracted data on population, intervention, outcome and methodological quality. Agreement between reviewers was high: differences were eventually resolved by third-party decision. The methodological quality of the studies was moderate ( mean 9.0, SD 1.7), and the outcomes of the randomized clinical trials were not related to their quality. Results Efforts to achieve an optimized hemodynamic condition resulted in a decreased mortality rate ( relative risk ratio (RR) 0.75 (95% confidence interval (CI) 0.62 to 0.90) in all studies combined. This was due to a significantly decreased mortality in peri-operative intervention studies ( RR 0.66 ( 95% CI 0.54 to 0.81). Overall, patients with sepsis and overt organ failure do not benefit from this method ( RR 0.92 ( 95% CI 0.75 to 1.11)). Conclusion This systematic review showed that interventions aimed at hemodynamic optimization reduced mortality. In particular, trials including peri-operative interventions aimed at the hemodynamic optimization of high-risk surgical patients reduce mortality. Overall, this effect was not related to the trial quality.