Reappraisal of diagnostic peritoneal lavage criteria for operation in penetrating and blunt trauma.

The criteria for declaring the results of a diagnostic peritoneal lavage (DPL) positive have been controversial. Lowered cell count criteria result in increased sensitivity, decreased specificity, and altered accuracy. Consecutive lavages on 105 patients with penetrating trauma (PT) to the lower chest and abdomen (48 gunshot wounds and 57 stab wounds) and 1812 patients with blunt abdominal trauma (BT) were studied. Varied cell count criteria were analyzed. The best criteria for BT were as follows: positive, lavage fluid red blood cells (LRBCs) greater than 100,000/mm3 or lavage fluid white blood cells (LWBCs) greater than 500/mm3; indeterminate, LRBCs 50,000/mm3 to 100,000/mm3 or LWBCs 100 to 500/mm3; and negative, LRBCs less than 50,000/mm3 and LWBCs less than 100/mm3. Based on these criteria the accuracy of the test was 99.1%. The highest accuracy would be achieved for PT if the criteria were as follows: positive, LRBCs greater than 50,000/mm3 or LWBCs greater than 500/mm3; indeterminate, LRBCs 25,000 to 50,000/mm3 or LWBCs 100 to 500/mm3; negative, LRBCs less than 25,000/mm3 and LWBCs less than 100/mm3. Based on these criteria the accuracy of the test for PT would range from 96.2% (101 of 105) to 98.1% (103 of 105), depending on the results of repeat lavage for two patients with indeterminate initial lavages. The standard lavage criteria were the best for BT and achieved the highest accuracy. However, the LRBC criteria should be lowered for PT.