Diaphragmatic function is markedly altered in cerulein-induced pancreatitis.

Abstract

To assess diaphragmatic function in vitro during experimental cerulein-induced acute pancreatitis. Prospective, randomized, controlled animal trial. Research laboratory at a large university medical center. Twenty male Sprague-Dawley rats, weighing 180 to 200 g. Sodium chloride 0.9% or cerulein (5 microg/kg/hr) was infused for 6 hrs. Isometric force generated during electrical stimulation of costal diaphragmatic strips was measured 6 hrs after the end of infusion. Diaphragmatic strength was assessed at different frequencies (10, 20, 30, 50, and 100 Hz). Endurance index was the time until the force generated during the 30 Hz repetitive stimulation decreased to 50% of the initial value (T50%). Histologic examination of the diaphragm was performed. A decrease averaging 40% in diaphragmatic strength generation was observed for all frequencies of stimulation in the pancreatitis group. Compared with the control group, this decrease was associated with a reduction in T50% (30.9 +/- 12.5 [SD] and 46.4 +/- 10.8 secs in pancreatitis and control, respectively; p< .05). No histologic alteration of the diaphragm was observed. Acute pancreatitis induced marked diaphragmatic dysfunction. Although the precise mechanisms responsible for this alteration are not precisely determined, diaphragmatic dysfunction may play a role in pancreatitis-associated respiratory failure.