Cumulative fluid uptake was 4.1 liter less in the RG on the 5th postoperative day ( p = 0.01 ) , and pulmonary function was better in these patients ( area under curve day 2-7 for forced vital capacity ( FVC ) , forced expiratory volume in one second ( FEV1 ) , peak expiratory flow ( PEF ) each < 0.05 ) .