Factors related to the prognosis of hyperbaric oxygen therapy for postoperative paralytic ileus

Postoperative paralytic ileus is one of the most common complications associated with abdominal surgery. Although the Japanese Society of Hyperbaric and Undersea Medicine officially approves paralytic ileus as an indication for hyperbaric oxygen therapy, the factors related to the prognosis of this therapy have not been determined. Accordingly, in this study, we evaluated factors that may be related to the prognosis of this therapy in patients with postoperative paralytic ileus. Patients in gastroenterological surgery, obstetrics and gynecology, and urology who underwent hyperbaric oxygen therapy for postoperative paralytic ileus from April 1, 2017, through March 31, 2022, were retrospectively evaluated. We set the primary outcome as the number of days to oral intake after the start of the therapy. First, we compared the differences in the number of days for various factors possibly related to its prognosis. Next, multivariate analysis using multiple linear regression analysis was performed. We evaluated 110 patients. Younger age, no prevalence of diabetes mellitus, the kind of surgery, no history of previous abdominal surgery, a shorter number of days from the onset to the start of therapy, and higher mean pressure of therapy had at least 1.5 fewer days of nothing by mouth. Multiple linear regression analysis revealed that only the mean pressure of therapy was a factor associated with the prognosis of hyperbaric oxygen therapy. Only the mean pressure of therapy is related to the prognosis of hyperbaric oxygen therapy. Further prospective studies adopting higher pressure therapy will be necessary to evaluate the efficacy of this treatment.