Efficacy of USCOM-monitored cardiac output and corrected flow time in guiding volume therapy in patients undergoing laparoscopic colorectal surgery

Objective To evaluate the efficacy of cardiac output (CO) and corrected flow time (FTc) monitored by ultrasonic cardiac output monitor (USCOM) in guiding volume therapy in patients undergoing laparoscopic colorectal surgery. Methods Eighty American Society of Anesthesiology physical status Ⅰ or Ⅱ patients, aged 18-60 yr, with body mass index of 18-25 kg/m2, undergoing laparoscopic colorectal surgery, were divided into 2 groups (n=40 each) using a random number table method: control group (group C) and USCOM-guided fluid therapy group (group U). Mean arterial pressure was maintained at 60-100 mmHg, central venous pressure at 5-10 cmH2O and urine volume>0.5 ml·kg-1·h-1using conventional fluid therapy in group C. In group U, goal-directed fluid therapy was performed under the monitoring of USCOM, FTc was maintained at 326-400 ms and CO at 4.2-5.9 L/min.The volume of crystalloid and colloid solution, total volume of fluid infused, blood loss, urine volume and requirement for vasoactive agents during surgery and time of surgery were recorded.Blood samples were collected from the left radial artery for determination of the blood lactate concentration immediately after anesthesia induction, at the end of the operation and at 1 and 2 days after surgery.The time of passing the first flatus after surgery, adverse cardiovascular events (hypertension, hypotension, cardiac insufficiency), pulmonary complications (pulmonary edema, pulmonary atelectasis), and oliguria and anuria within 24 h after surgery, and length of hospital stay were recorded. Results Compared with group C, the volume of crystalloid, total volume of fluid infused and urine volume were significantly decreased during surgery, the volume of colloid solution was increased during surgery, the blood lactate concentration was decreased at the end of surgery, the incidence of postoperative cardiovascular and pulmonary complications was decreased, and the time of passing the first flatus after surgery and length of hospital stay were shortened in group U (P<0.05). Conclusion USCOM-monitored CO and FTc produces better efficacy in guiding volume therapy and is helpful for improving recovery in patients undergoing laparoscopic colorectal surgery. Key words: Ultrasonography; Fluid therapy; Colonic neoplasms