Objective:To investigate the effect of end-expiratory positive pressure of pulmonary protective ventilation strategy in overweight patients undergoing laparoscopic surgery.Methods:Forty overweight patients, 24 kg/m 2≤BMI<28 kg/m 2, aged 20-65yr, of American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, scheduled for elective laparoscopic surgery to radical resection of rectal cancer under general anesthesia, were randomly divided into 2 groups ( n=20 each) using a random number table: positive end-expiratory pressure (PEEP) group (group P), control group (group C). The rest of the settings in mechanical ventilation were the same in both groups, tidal volume (Vt)=6 ml/kg, initial respiration frequency (RR)=15 bpm, oxygen inhalation 100%, inspiratory expiratory time ratio ( I∶E)=1∶2. The concentration of oxygen inhalation was 50% and respiration frequency was adjusted to maintain P ETCO 2 35-45 mmHg after endotracheal intubation. The heart rate (HR), mean arterial pressure (MAP), tidal volume (Vt), airway peak pressure (Ppeak), airway pressure platform (Pplat) were recor-ded, and the lung dynamic compliance (Cdyn) was calculated; arterial oxygen partial pressure (PaO 2) and partial pressure of carbon dioxide in arterial blood (PaCO 2) were measured by gas analyzer; oxygenation index (OI) was calculated at the time of before induction of anesthesia (T 0) , 5 min after endotracheal intubation (T 1), 5 min after laparoscopic pneumoperitoneum (T 2), 60 min after laparoscopic pneumoperitoneum (T 3), and suturing the skin (T 4). The postoperative pulmonary complications were observed 3 days after surgery. Results:There was no significant difference between the two groups in patients characteristics and operative indicators ( P>0.05). Compared with T 0, the mean arterial blood pressure of the two groups decreased at T 3 and T 4, and there was no significant difference in heart rate at each time ( P>0.05). There was no significant difference in hemodynamic parameters between the two groups ( P>0.05). Compared with T 1, VT increased at T 2 in group P and T 3 in group C, while there was no significant difference in VT between the two groups ( P>0.05); compared with T 1, Ppeak and Pplat increased at T 2 and T 3 in both groups, while there was no significant difference between the two groups ( P>0.05); compared with T 1, Cdyn of the two groups decreased at T 2 and T 3 ( P<0.05), and cdyn of the P group at each time were higher than that of the group C ( P<0.05). Compared with T 1, PaO 2 and OI decreased and PaCO 2 increased at T 2, T 3 and T 4 in the two groups ( P<0.05). PaO 2 and OI at T 3 and T 4 in the P group were higher than those in the C group ( P<0.05). There was no significant difference in PaCO 2 between the two groups ( P>0.05). There was no significant difference in the incidence of pulmonary complications between the two groups ( P>0.05). Conclusions:Positive end-expiratory pressure of protective ventilation strategy from the induction period of general anesthesia can effectively improve dynamic lung cdyniance, improve oxygenation and promote pulmonary function recovery in overweight patients undergoing laparoscopic surgery.

Three cases of dermatomyositis presenting with inverse Gottron's papules were reported.Of the 3 patients,there were 2 males and 1 female aged 43,41 and 46 years respectively,whose disease durations were 1,6,7 months respectively.Inverse Gottron's papules manifested as papules overlying the palmar aspect of the metacarpal and interphalangeal joints,which were arranged in a linear pattern in 2 cases.Of the 3 cases,1 presented with interstitial pneumonia,3 with myositis,and 2 showed negative anti-nuclear antibody test.Histopathological examination of inverse Gottron's papules in 1 case revealed focal liquefaction degeneration of basal cells and perivascular infiltration with inflammatory cells,especially lymphocytes,in the superficial dermis.The 3 patients received oral glucocorticoids and immunosuppressive agents in the early period of treatment.After 3-month treatment,clinical symptoms including muscle weakness and muscle pain were improved evidently,but no obvious improvement in inverse Gottron's papules was observed.After 1-year treatment,these papules on the palmar aspect were markedly relieved in 1 case.