McMahon et al described features of free peritoneal fluid and peritoneal lavage fluid associated with severe acute pancreatitis. The authors are from the Leeds General Infirmary in England.


(1) Prep a point 2 cm below the umbilicus in the midline. If this point cannot be used, select a point midway between the umbilicus and either the left or right anterior superior iliac spine.

(2) Insert a suitable catheter into the peritoneal cavity. Originally this was a peritoneal dialysis catheter.

(3) Once the catheter had been advanced, any free fluid was aspirated with a syringe.

(4) One liter of warmed sterile normal saline was then infused and the patient rolled gently from side to side.

(5) The lavage fluid was then allowed to drain out freely.


Parameters associated with severe acute pancreatitis:

(1) amount of free peritoneal fluid

(2) color of free peritoneal fluid prior to lavage

(3) color of lavage fluid





free peritoneal fluid

<= 10 mL



> 10 mL


color of free peritoneal fluid

clear to medium brown



dark to very dark brown


color of lavage fluid

clear to light brown



medium brown or darker




• Corfield et al use 20 mL as the cutoff for free peritoneal fluid.


For evaluation of fluid color, McMahon et al provide a color chart (Figure 1, page 23) with 8 tubes containing fluid ranging from water (clear) to a dark opaque brown.


Color of Fluid

Analogue Color

medium brown

English beer "bitter"

dark brown

prune juice (or perhaps Guiness)


total number of findings present =

= SUM(points for all 3 factors)



• minimum number of findings: 0

• maximum number of findngs: 3

• The presence of one or more of these findings was associated with severe acute pancreatitis.

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