Effects of obesity on pulmonary function in patients during and after cholecystectomy / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of obesity on functional residual capacity ( FRC ) , ventilatory function and gas exchange during and after cholecystectomy. Methods Twenty ASA Ⅰ or Ⅱ patients of both sex aged 26-58yr undergoing elective cholecystectomy were divided into 2 groups according to the body mass index (BMI): control group BMI 30 (n = 10) . The patients were premedicated with intramuscular luminal 1.0 g and atropine 0.5 mg. Anesthesia was induced with midazolam 2-3 mg, fentanyl 5?g?*kg-1, propofol 1.5-2.0 mg?kg and vecuronium 0.1 mg?kg-1 and maintained with infusion of propofol (at 8-10 mg?kg-1?h-1) and fentanyl (at 1-2 ?g?kg-1?h-1) and intermittent i.v. boluses of vecuronium after tracheal intubation. The patients were mechanically ventilated (VT 10ml?kg-1,I:E=1:2, FiO2 100%) and PETCO2 was maintained at 35-40 mm Hg by adjusting the respiratory rate. Pethidine 1 mg?kg-1 was given i.m. every 8 h after operation for analgesia. BP, HR, ECG, SpO2, PET CO2 , FiO2, VT , RR were monitored during anesthesia. Arterial blood samples were taken before anesthesia (T0, baseline), 15 min after induction of anesthesia (T1), 30 min after skin incision (T2) and 6, 24 h after operation (T3,4) for blood gas analysis. FRC (closed-circuit helium dilution method), forced vital capacity (FVC), forced expiratory volume at 1 second (FEV10) and maximal mid-expiratory flow volume (MMF) were measured before and 6 h and 24 h after operation.Results FRC was significantly decreased after induction of anesthesia, during and after operation compared with the baseline value (T0) in both groups and the decrease in FRC was significantly larger in obesity group than in control group (P