Patient selection:
(1) patients with a tangential-to-abdomen, thoraco-abdominal or transpelvic gunshot wound
(2) no clear indication for laparotomy (shock, peritonitis, pneumoperitoneum, gross blood per nasogastric tube, gross blood on rectal examination) present
Procedure:
(1) diagnostic peritoneal lavage performed as described in previous section
(2) wounds involving the back or flank were evaluated by triple-contrast CT to exclude injury to the retroperitoneum
(3) transpelvic wounds were evaluated by proctoscopy, cystourethrography and vaginal examination (in women)
(4) patients with negative peritoneal lavage were observed in the hospital for 24 hours
Threshold for laparotomy: 10,000 RBC per µL in effluent fluid
(1) The threshold of 100,000 per µL is considered too high in this situation since commonly injured structures such as the diaphragm or hollow viscus tend to bleed less than a ruptured solid organ.
Organs found most commonly injured at laparotomy:
(1) liver
(2) diaphragm
(3) colon
Performance of algorithm in series:
• 6/150 false positive
• 2/279 false negative
• sensitivity 99%, specificity 98% and diagnostic accuracy 98%
