Maintenance of cardiac index within normal range is associated with mortality reduction in patients undergoing major urological surgery

Introduction

Hemodynamic optimisation based on flow variables allows an early detection and correction of possible occult organ hypoperfusion in patients undergoing major surgery. Shoemaker described a markedly decreased cardiac index (CI) in nonsurvivors, which remained significantly below the values compared with survivors during the surgery. The aim of this study was to evaluate the length of ICU stay, overall in-hospital stay and the postoperative outcome in a group of patients undergoing major urological surgery, while the CI is maintained within the normal range during intraoperative period.

Methods

Patients were randomised into groups the day before surgery - conventional management group (decision about fluid therapy and vasoactive support was based on internal guidelines to preserve normal macrohemodynamic variables), and protocol group. Each patient in the protocol group received an oesophageal Doppler probe (TED) (Hemosonic 100; Arrow International, USA) after the start of general anaesthesia and then hemodynamic optimisation (fluid management and vasoactive drugs), according to TED variables, was performed to keep CI between 2.6 and 3.8 l/minute/m².

Results

We enrolled 230 patients. The control group: n = 115 and the protocol group: n = 115. High-risk criteria surgery was fulfilled in 43% patients in protocol group and 45% in control group. There were no significant differences in baseline variables between both groups (age, gender, length of surgical procedure, estimated blood loss and also in intraoperative values of MAP and CVP). In the protocol group was observed a high frequency of CI <2.6 l/minute/m² after induction of anesthesia 75% with fast recovery of CI. The volume of fluids (Ringer's solution and HES 6% 130/0.4) administered during surgery was lower in the control group (medians: 2,800 ml vs 3,800 ml, P < 0.05). Amount of used blood units (RBC 71 vs 133, P = 0.001; FFP 71 vs 142, P < 0.001) was higher in control group. Significant differences have also been found in the use of vasoactive agents. Total number of postoperative complications (P < 0.001), the ICU stay and overall in-hospital stay (medians: 2 vs 3 days, P = 0.041, and 9 vs 11 days, P = 0.014), in-hospital mortality (2.6% vs 10.4%, P = 0.029) were in favour of the protocol group of patients.

Conclusions

Hemodynamic optimisation guided by TED can improve postoperative outcome in patients after major urological surgery. Maintaining normal values of CI is an applicable target of intraoperative therapeutic intervention.