Diagnostic peritoneal lavage: volume of lavage effluent needed for accurate determination of a negative lavage

While the ability of diagnostic peritoneal lavage (DPL) to 'rule out' occult intra-abdominal injuries has been well established, the volume of lavage effluent necessary for accurate prediction of a negative lavage has not been determined. To address this, 60 injured adults with blunt (N = 45) or penetrating (N = 15) trauma undergoing DPL were evaluated prospectively through protocol. After infusion of 1l of Ringer's lactate solution, samples of lavage effluent were obtained at 100 cm3, 250 cm3, 500 cm3, and 759 cm3, and when no more effluent could be returned (final sample). DPL was considered negative if final sample RBC count was < or = 100,000/mm3 for blunt injury and < 50,000/mm3 for penetrating injury. The conclusion is that at 100 cm3 of lavage effluent returned, negative results are highly predictive of a negative DPL (98 per cent), though 250 cm3 of lavage effluent is required to predict a negative DPL uniformly (100 per cent).