Choosing the location for non-image guided abdominal paracentesis.

OBJECTIVES: The optimal location for paracentesis has not been studied scientifically. The evolving obesity epidemic has changed the physique of many patients with cirrhosis and ascites such that needles inserted into the abdominal wall may not reach fluid. We aimed to determine the location for paracentesis that would have the thinnest abdominal wall and the deepest amount of fluid.

METHODS: Ultrasound measurements of abdominal wall thickness and depth of ascites were recorded in two locations, the infraumbilical midline (ML) and the left lower quadrant (LLQ), in 52 patients with cirrhosis and ascites admitted to a single inpatient liver unit.

RESULTS: The abdominal wall was significantly thinner (1.8 vs. 2.4 cm; P<0.001) and the depth of ascites greater (2.86 vs. 2.29 cm; P=0.017) in the LLQ as compared with the infraumbilical ML position. In the left lateral oblique position, the difference in the depth of ascites was more pronounced when comparing the LLQ with the infraumbilical ML (4.57 vs. 2.78 cm; P<0.0001).

CONCLUSIONS: The LLQ is preferable to the ML infraumbilical location for performing paracentesis.