REDUCED LYMPHATIC DRAINAGE OF DIALYSATE FROM THE PERITONEAL-CAVITY DURING ACUTE PERITONITIS IN SHEEP

Objectives: The purpose of this study was to investigate the effects o f acute peritonitis on lymphatic drainage of the peritoneal cavity in conscious sheep.Design: Peritonitis was induced with the addition of 1 % casein or 1% albumin to the dialysis solution. Thirty sheep (5 group s of 6) were used in this study. One group received 50 mL/kg intraperi toneal infusions of Dianeal 4.25% (486 mOsm/L); a second group receive d 1% casein-Dianeal 4.25% (493 mOsm/L); a third group received 1% albu min-Dianeal 4.25% (487 mOsm/L). In the fourth and fifth groups (contro ls and casein-injected) lymph was collected from the caudal mediastina l lymph node and the thoracic duct, both of which are involved in the lymphatic drainage of the peritoneal cavity (peritonitis induced with casein). I-125-human serum albumin (25 mu Ci) was added to the dialysa te as the lymph flow marker. Lymph drainage was estimated from (1) the appearance of the intraperitoneally administered tracer in the blood; (2) the disappearance of the tracer from the peritoneal cavity; and ( 3) the recovery of tracer in lymph. Results: In noncannulated animals the cumulative volume removed by lymphatics over 6 hours (based on tra cer recovery in blood) was 10.5 +/- 1.0 mL/kg in control animals versu s 5.0 +/- 0.6 mL/kg and 8.6 +/- 1.2 mL/kg in casein and albumin-infuse d sheep, respectively. The suggestion of decreased lymph drainage in p eritonitis was supported by the cannulation experiments. While the cum ulative fluid removed from the peritoneal cavity over 6 hours in cauda l lymph was unaffected by peritonitis (3.8 +/- 0.4 mL/kg in controls v s 3.6 +/- 0.5 mL/kg in casein-injected animals), peritonitis reduced f low into the thoracic duct from 3.0 +/- 0.3 to 1.1 +/- 0.3 mL/kg. The sum of the volume removed in lymph in the cannulated preparations was 6.8 +/- 0.4 mL/kg in controls versus 4.7 +/- 0.5 mL/kg in the peritoni tis group. The total volume removed from the cavity (including an esti mate of flow based on the residual recovery of tracer in blood) was re duced from 12.6 +/- 1.4 in controls to 7.8 +/- 0.6 mL/kg in the perito nitis sheep. In contrast, estimates of lymph drainage based on the dis appearance of tracer from the peritoneal cavity suggested that lymph d rainage increased (from 15.6 +/- 1.6 mL/kg in controls to 17.8 +/- 1.5 mL/kg and 25.5 +/- 1.7 mL/kg in the casein and albumin groups, respec tively, in noncannulated animals and from 15.3 +/- 1.4 mL/kg in contro ls to 25.0 +/- 1.7 mL/kg in the cannulated group). In both noncannulat ed and cannulated sheep the total recovery of tracer was less in the p eritonitis groups. Conclusions: These studies demonstrated that lymph drainage of the peritoneal space was decreased in a casein peritonitis model. The decrease in lymph drainage is most obvious in the visceral pathway leading to the thoracic duct; however, diaphragmatic drainage into the right lymph duct may also be inhibited. The disappearance of tracer from the peritoneal cavity was elevated during peritonitis. Tr acer disappearance has been used to estimate lymph drainage, but this approach suggested, incorrectly, that lymph flow had increased.