DIAPHRAGMATIC FUNCTION IS MARKEDLY ALTERED IN CERULEIN-INDUCED PANCREATITIS

Objective: To assess diaphragmatic function in vitro during experiment al cerulein induced acute pancreatitis. Design: Prospective, randomize d, controlled animal trial. Setting: Research laboratory at a large un iversity medical center. Subjects: Twenty male Sprague Dawley rats, we ighing 180 to 200 g. Interventions: Sodium chloride 0.9% or cerulein ( 5 mu g/kg/hr) was infused for 6 hrs. Measurements and Main Results: Is ometric force generated during electrical stimulation of costal diaphr agmatic strips was measured 6 hrs after the end of infusion. Diaphragm atic strength was assessed at different frequencies (10, 20, 30, 50, a nd 100 Hz). Endurance index was the time until the force generated dur ing the 30 Hz repetitive stimulation decreased to 50% of the initial v alue (T50%). Histologic examination of the diaphragm was performed. A decrease averaging 40% in diaphragmatic strength generation was observ ed for all frequencies of stimulation in the pancreatitis group. Compa red with the control group, this decrease was associated with a reduct ion in T50% (30.9 +/- 12.5 [SD] and 46.4 +/- 10.8 sees in pancreatitis and control, respectively; p<.05). No histologic alteration of the di aphragm was observed. Conclusions: Acute pancreatitis induced marked d iaphragmatic dysfunction. Although the precise mechanisms responsible for this alteration are not precisely determined, diaphragmatic dysfun ction may play a role in pancreatitis-associated respiratory failure.