Diagnostic peritoneal lavage

Diagnostic peritoneal lavage (DPL) is performed when intra-abdominal bleeding (hemoperitoneum) usually secondary to trauma is suspected. Nowadays DPL is largely abandoned in favour of abdominal ultrasound. Often surgeons have little experience in performing DPL and haematology departments have troubles analyzing the sample. The procedure is still performed when alternative diagnostic methods such as computerized tomography (CT) or ultrasound imaging are unavailable, or when the patient’s condition does not allow such procedures to be performed. The procedure was first described in 1965.

Procedure
After local anesthesia, a vertical skin incision is made one third of the distance from the umbilicus to the symphisis pubis. The linea alba is divided and the peritoneum entered after it has been picked up to prevent bowel perforation. A catheter is inserted towards the pelvis and aspiration of material attempted using a syringe. If no blood is aspirated, 1 litre of warm 0.9% saline is infused and after a few (usually 5) minutes this is drained and sent for analysis.

Analysis
10ml of blood or enteric contents (stool, food, etc.) constitutes a positive DPL, and operative exploration is warranted. Other positive findings include more than 100,000 RBCs/ml, 500 WBCs/ml, and amylase 175 IU. Lower thresholds may also be used, which will result in fewer false-negative tests, but increase the rate of negative laparotomy. Levels of 10,000 RBCs/ml are typically used in cases of penetrating trauma.