Changes

*'''Creatinine''' and '''potassium''' if the effusion is thought to be a uroabdomen; creatinine levels in a peritoneal sample that are higher than serum concnetrations indicate uroperitoneum.

*'''Creatinine''' and '''potassium''' if the effusion is thought to be a uroabdomen; creatinine levels in a peritoneal sample that are higher than serum concnetrations indicate uroperitoneum.

*'''Glucose''' and '''lactate''' should be measured; where their values are <2.8 mmol/l and >5.5 mmol/l respectively the inflammation is likely to be septic.

*'''Glucose''' and '''lactate''' should be measured; where their values are <2.8 mmol/l and >5.5 mmol/l respectively the inflammation is likely to be septic.

Lactate levels are indicative of a hypoxic crisis and levels are occasionally used as a prognostic indicator - rising levels in the face of vigorous treatment of peritonitis seem to be anecdotally be more prognostically useful than absolute cut off values. NB. Measurement of lactate on some machines such as hand held blood gas analysers may require a heparin sample.  

Lactate levels are indicative of a hypoxic crisis and levels are occasionally used as a prognostic indicator - rising levels in the face of vigorous treatment of peritonitis seem to be anecdotally more prognostically useful than absolute cut off values. NB. Measurement of lactate on some machines such as hand held blood gas analysers may require a heparin sample.  

*Culture is indicated where a bacterial infection is suspected, and should include an anaerobic culture.

*Culture is indicated where a bacterial infection is suspected, and should include an anaerobic culture.