SUCRALFATE DOES NOT REDUCE THE RISK OF ACID ASPIRATION PNEUMONITIS

Objective: To study the pulmonary effects of aspirating a mixture of s ucralfate in water and sucralfate in hydrochloric acid in an animal mo del of aspiration pneumonia. Design: Prospective, randomized, controll ed study with repeated measures. Setting: University research laborato ry. Subjects: Thirty-two in situ, isolated, blood perfused porcine lun g preparations. Interventions: Five control preparations received no a spiration. Twenty-seven preparations received a standard aspiration of 1.5 mL/kg body of a) distilled water (n = 5), b) sucralfate in distil led water (n = 8), c) 1/10 normal hydrochloric acid (n = 6), and d) mi xture of sucralfate in distilled water and hydrochloric acid (n = 8). Measurements: The pH measurements were made of all aspirates. Lung wei ght, airway pressures, and pulmonary artery pressures were continuousl y monitored before and for 4 hrs after aspiration. Lung wet/dry weight ratio was measured at the completion of the study. Results: The pH of sucralfate mixed with distilled water was 4.9, pH of 1/10 normal hydr ochloric acid was 1.0, and pH of equal volumes of a sucralfate-water s uspension mixed with hydrochloric acid was 1.5. Airway pressures and p ulmonary arterial pressures increased in all aspirate groups over time compared with those values of control lungs. Control lungs gained 18 +/- 3 (SEM) g over 4 hrs and the wet/dry ratio was 4.951 +/- 0.310. Lu ngs aspirating distilled water gained 147 +/- 49 g and the wet/dry rat io was 5.198 +/- 0.120. Lungs aspirating sucralfate and distilled wate r increased their weight by 109 +/- 30 g and the wet/dry ratio was 5.3 80 +/- 0.076. Lungs aspirating a suspension of sucralfate and water an d hydrochloric acid were similar to lungs aspirating hydrochloric acid alone with weight increases of 265 +/- 30 g and 346 +/- 81 g, and the wet/dry ratio of 7.011 +/- 0.273 and 7.230 +/- 0.390, respectively. C onclusions: Sucralfate has minimal acid buffering effect. Aspiration o f sucralfate mixed with distilled water causes lung edema similar to a spiration of water alone. Aspiration of a sucralfate-water suspension mixed with hydrochloric acid causes severe lung edema. These results s uggest that patients given sucralfate prophylaxis for stress ulceratio n are at risk for acid aspiration.