Effect of dynamic lung compliance-guided PEEP titration on extravascular lung water in elderly patients undergoing robot-assisted radical prostatectomy

Abstract

Objective To evaluate the effect of dynamic lung compliance(Cdyn)-guided positive end-expiratory pressure(PEEP)titration on extravascular lung water in elderly patients undergoing robot-assisted radical prostatectomy. Methods Forty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients, aged 65-80 yr, with body mass index of 19-28 kg/m2, scheduled for elective robot-assisted radical prostatectomy, were divided into 2 groups(n=20 each)using a random number table method: control group(group C)and PEEP group(group P). In group P, immediately after endotracheal intubation, immediately after establishing pneumoperitoneum-Trendelenburg position and after restoring the supine position, PEEP was set starting from the lowest PEEP allowed by the machine, increasing by 2 cmH2O every 4 min until the maximum Cdyn was obtained.PEEP was not set in group C. Immediately after establishing the invasive blood pressure monitoring(T1), at 10 min after the first successful PEEP titration(T2), 10 min, 1 h and 2 h after the second successful PEEP titration(T3-5), 10 min after the third successful PEEP titration(T6), and 30 min after tracheal extubation(T7)in group P, or at T1, 10 min after intubation(T2), 10 min, 1 h and 2 h after establishing pneumoperitoneum-Trendelenburg position(T3-5), 10 min after restoring the supine position(T6)and T7 in group C, blood samples were collected from the radial artery for blood gas analysis, and the oxygenation index was calculated.The B-line score was recorded at T1 and T7. Results Compared with group C, the B-line score was significantly decreased at T7, and the oxygenation index was increased at T5-7 in group P(P<0.05). Conclusion Cdyn-guided PEEP titration can decrease the formation of extravascular lung water in elderly patients undergoing robot-assisted radical prostatectomy. Key words: Positive-pressure respiration; Extravascular lung water; Prostatic neoplasms; Robotic surgical procedures