The comparative clearance rates of the pleural and peritoneal cavities

We compared the rates of bacterial clearance from the pleural and peritoneal cavities of rats after contamination with 1 x 10(6) live Escherichia coli. Pleural clearance was enhanced beginning at 30 minutes after injection and extended to at least six hours. At 24 hours, the clearance was similar for both the pleural and peritoneal groups. Blood and organ bacterial cultures were similar between these two groups. White blood cell populations were similar at rest, but there was a greater increase in the leukocyte population in the pleural cavity six hours after E coli stimulation. We postulate that the increased clearance of E coli from the pleural cavity may be due to differences in lymphatic absorption, recruitment of leukocytes, or fibrin trapping of bacteria.