Potassium sorbate reduces gastric colonization in patients receiving mechanical ventilation

Objectives: Tube feeding might increase gastric burden of pathogenic bacteria and predispose patients to ventilator-associated pneumonia. We sought to determine whether a tube feeding formula acidified using potassium sorbate could reduce gastric burden of potentially pathogenic bacteria. Design: Prospective, randomized, double-blind trial. Setting: RML Specialty Hospital, a facility with expertise in weaning patients from prolonged mechanical ventilation. Patients: Thirty patients recovering from prolonged mechanical ventilation. Intervention: Patients were randomized to receive either a standard tube feeding formula (n = 14) or a formula acidified using potassium sorbate to a pH of 4.25 (n = 16). Measurements and Results: Weekly quantitative cultures of gastric aspirates. The number of colony-forming units (CFUs) per patient was higher in the control than in the treatment group (53% ± 11% vs 9% ± 3.4%, threshold of ≥100000 CFU/mL fluid, P = .003). The number of organisms isolated in each patient per week was higher among patients receiving standard tube feeding formula than among patients receiving acidified formula (0.91 ± 0.20 vs 0.13 ± 0.05 organisms per patient per week, threshold of ≥100000 CFU/mL fluid, P = .0014). There was no difference in the incidence of gastrointestinal bleeding or ventilator-associated pneumonia between study groups. Conclusion: Tube feeding formula acidified using potassium sorbate was well tolerated and reduced gastric bacterial burden in patients recovering from prolonged mechanical ventilation.