Effect of fluid strategy on stroke volume, cardiac output, and fluid responsiveness in adult patients undergoing major abdominal surgery: a sub-study of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial

BackgroundWe designed a prospective sub-study of the larger Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial to measure differences stroke volume and other haemodynamic parameters at end intraoperative fluid protocols. The effects two regimens may increase our understanding observed perioperative outcomes.MethodsStroke cardiac output were measured with both an oesophageal Doppler ultrasound monitor arterial pressure waveform analysis. Stroke variation, pulse plethysmographic variability index also obtained. A passive leg raise manoeuvre was performed identify responsiveness.ResultsAnalysis 105 patients showed that primary outcome, monitor-derived index, higher liberal group: restrictive 38.5 (28.6–48.8) vs 44.0 (34.9–61.9) ml m?2; P=0.043. Similarly, there 2.96 (2.32–4.05) 2.42 (1.94–3.26) L min?1 P=0.015. Arterial-pressure-based did not differ, nor significant difference or index. responsiveness 40% 30% protocol (not significant).ConclusionsThe group from RELIEF had significantly compared period. Measures differ between groups.Clinical registrationACTRN12615000125527.