Background and objective: It was previously reported that topical ketamine inhibits albumin extravasation in a rat chemical peritonitis model. Using the same model, the present study investigated whether intravenous ketamine inhibited this extravasation.

Methods: Twenty-four rats anaesthetized with pentobarbital (75 mg kg−1) were randomly assigned to two groups: ketamine and a 0.9% NaCl (saline) group (n = 12 each). Ketamine 1% or saline 0.1 mL kg−1 min−1 was given intravenously for 60 min to the respective group. After the abdomen had been opened, peritonitis was elicited by topically applying a filter paper containing 0.02 M HCl 0.07 mL onto the surface of the appendix or caecum for 5 min. Fifteen minutes after removal of the filter paper, Evans' blue dye (50 mg kg−1) was injected intravenously. The extravasated dye was colorimetrically quantified by a spectrophotometer at 620 nm.

Results: The infusion of ketamine significantly reduced Evans' blue extravasation: 5.26 (range 4.18–6.34) μg per 100 mg tissue compared with the saline group control: 6.81 (5.93−7.69) μg per 100 mg tissue (P < 0.05).

Conclusions: It is suggested that ketamine anaesthesia may reduce albumin extravasation in inflammatory tissues.