ABSTRACT
Objective:To investigate the effect of individualized positive end-expiratory pressure (PEEP) on postoperative lung complications in patients undergoing cardiac valve replacement.Methods:Sixty-four patients of both sexes, aged 40-70 yr, with body mass index of 18-26 kg/m 2, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, with New York Heart Association class Ⅱ or Ⅲ, undergoing elective cardiac valve replacement (single or double) from July to October 2020, were enrolled in this study.The patients were divided into 2 groups ( n=32 each) using a random number table method: control group (group C) and individualized PEEP group (group P). After recruitment maneuver, group C was set with a fixed PEEP of 4 cmH 2O, group P was titrated using a PEEP-step method, and PEEP was set at 4 cmH 2O after admission to intensive care unit (ICU). Before induction of anesthesia (T 0), before recruitment maneuver (T 1), at 20 min after PEEP ventilation (T 2), at 2 h after surgery (T 3), and at 24 h after surgery (T 4), arterial blood samples were taken for determination of serum interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) concentrations.The hemodynamic indicators (heart rate, mean arterial pressure and central venous pressure) at T 1-T 4 were recorded.Pulmonary complications were diagnosed according to clinical manifestations, imaging and blood gas analysis during the postoperative hospitalization.The postoperative length of hospital stay, extubation time and duration of ICU stay were recorded. Results:PEEP in group P [(6.1±1.4)cmH 2O] was significantly higher than that in group C ( P<0.05). Compared with group C, the concentrations of serum IL-6 and TNF-α at T 3 were significantly decreased, central venous pressure at T 2 was increased, and the incidence of postoperative pulmonary complications was decreased ( P<0.05), and no significant change was found in the length of hospital stay, extubation time and duration of ICU stay in group P ( P>0.05). Conclusion:Early application of individualized PEEP after termination of cardiopulmonary bypass can decrease the risk of postoperative pulmonary complications in patients undergoing cardiac valve replacement.