Effects of positive end-expiratory pressure (PEEP) ventilation on the exocrine pancreas in minipigs

Abstract

The effect of positive end-expiratory pressure (PEEP) ventilation on the pancreas was studied in 22 anesthetized minipigs. Five pigs were treated with intermittent positive pressure ventilation (IPPV) for 21 h (Group I) and six pigs were treated with a PEEP of 15 cm H2O for 21 h (Group II). We next explored the influence of PEEP ventilation while stimulating the pancreas with Ceruletide, a synthetic cholecystokinin (CCK) analog, at 2.3 micrograms/kg per h.i.v. for 3 h. Ventilation with IPPV for 4 h (n = 5, group III) was compared with PEEP of 15 cm H2O for 4 h (n = 6, group IV). Changes in serum-lipase were observed in all groups. The average lipase level rose from 12.6 U/l to 67 U/l group I and from 15.1 U/l to 129.2 U/l in group II (P = 0.025 for group I vs group II). In group IV (PEEP and Ceruletide), the mean lipase level rose about six times more than in group III (IPPV and Ceruletide). The difference was significant (P less than 0.00005). By three-factor ANOVA analysis, effects due to the drug (P less than 0.000006) and to PEEP (P less than 0.038) as well as a threefold interaction could be demonstrated, i.e., using Ceruletide a greater PEEP effect on lipase than without the drug (P less than 0.023) took place. There were no significant histological changes of the pancreas in groups I and III. In group II (21 h PEEP), vacuolization of acinar cells was evident; on the ultrastructural level, indication was given that these vacuoles derived both from the Golgi apparatus and from fusion of individual zymogen granules. In group IV (PEEP and Ceruletide), the focal appearance of fatty-tissue necrosis and acinar cells as well as hemorrhage of the gland was observed. We conclude that PEEP ventilation impairs the function of the pancreas and produces even more deleterious effects when the gland is stimulated. These effects should be considered when PEEP is used in clinical practice in the treatment of acute pancreatitis.

Clinical outcomes in patients with ICU-related pancreatitis

“…Acute lung injur y and respirator y failure are frequent and potentially fatal complications of acute pancreatitis [15,16] . Impor tantly, the institution of positive pressure mechanical ventilation can itself induce acute pancreatitis by exacerbating splanchnic hypoperfusion [1,17] . Recent studies have reported that elevated serum lipase levels are frequently encountered in critically ill patients, and hypoperfusion and inflammatory processes associated with multiple-organ failure appear to result in pancreatitis.…”