Milrinone is better choice for controlled low central venous pressure during hepatectomy: A randomized, controlled trial comparing with nitroglycerin.

Background: To explore the feasibility and effectiveness of controlled low central venous pressure(CLCVP)induced by milrinone during hepatectomy, and its influence on perioperative hemodynamics, blood loss and patients' recovery, comparing with the traditional method by nitroglycerin.

Methods: 52 patients who underwent elective open hepatectomy were enrolled in the study and randomly divided into two groups: milrinone (M) group and nitroglycerin (NG) group. Milrinone was infused with the rate of 0.5 μg/kg/min in group M, while nitroglycerin was given 0.2-0.5 μg/kg/min in group NG to maintain CVP≤ 5 mmHg during liver resection. The demographic variables, data of the operative procedure and intraoperative hemodynamics were recorded. The postoperative recovery profiles and pre- and post-operative haematological markers of vital organs were also collected and compared.

Results: 1. The blood loss of group M, no matter during liver resection or in the whole procedure, was both less than that of group NG (P < 0.05), so did the hemoglobin detected by blood gas analysis (P < 0.05). Meanwhile, time of hepatectomy and hepatic hilum occlusion were shorter in group M (P < 0.05). 2. Compared with the NG group, cardiac index (CI) and stroke volume index (SVR) were higher in group M in the operation. The norepinephrine dosage necessary in the operation was of no difference in two groups (P > 0.05). 3. Drainage indwelling time and postoperative hospital stay of group M were shorter than that of group NG (P < 0.05). Most of the blood biomarkers increased on postoperative day (POD)-1, and returned to the preoperative level on POD-7 without inter-group difference (P > 0.05). Brain natriuretic peptide precursor (Pro-BNP) in group M was higher than NG group on POD-1 (P < 0.05), and the statistical difference disappeared on POD-7.

Conclusion: Milrinone can effectively maintain a controlled low central venous pressure during hepatectomy. Compared with nitroglycerin, milrinone can reduce the amount of blood loss, with the benefit of better manifestation of hemodynamics and enhanced postoperative recovery.