Hypophosphatemia Is Associated with Post-Operative Ileus After Right Colon Resection

BackgroundElectrolyte imbalances are known to contribute to intestinal ileus. However, the direct impact of hypophosphatemia on post-operative ileus (POI) is unknown. ObjectiveTo describe post-operative phosphate dynamics and if hypophosphatemia is associated with POI after a right colon resection. DesignComparative retrospective cohort study SettingsHigh-volume tertiary referral center PatientsPatients who underwent right colon resection, which includes right hemicolectomies and ileocolic resections between 2020 and 2022. Main Outcome MeasuresPOI incidence, post-surgical phosphate dynamics, and post-operative phosphate deficit and recovery. ResultsA total of 396 patients were reviewed, where 68% of resections were for inflammatory bowel disease. Patients had a mean return of bowel function on POD 3.78 {+/-} 1.45. 17.4% of patients overall had POI. Serum phosphate was the most dynamic post-operative electrolyte, with statistically significant differences between POI and non-POI on POD 1, 3, and 7 (p < 0.05). Serum phosphate recovery in patients with POI was impaired at 0.11 mg/dL/day versus 0.17 mg/dL/day (p < 0.001). Patients with POI had a phosphate deficit that persisted beginning on POD 2, with statistically significant deficits on POD 3-5 (p < 0.01), as well as POD 7 (p < 0.001). On multivariate analysis, a phosphate deficit on POD 3 (ORadj 9.04, 95% CI 1.38-59.2), POD 5 (ORadj 7.05, 1.13-44.1), and POD 7 (ORadj 47.2, 2.98-749.4) were the only independent risk factors for POI. LimitationsGeneralizability of these findings may be limited outside of right colon resections. ConclusionsWe have established baseline phosphate dynamics in patients who undergo ileocolic anastomoses. We found POI was associated with a delayed serum phosphate recovery, as well as lower overall phosphate levels. Thus, a potential post-surgical window for intervention with timed phosphate repletion may have the potential to reduce post-operative ileus, need for nasogastric decompression, and ultimately decrease hospital length of stay.