Background Electrolyte imbalances are known to contribute to intestinal ileus. However, the direct impact of hypophosphatemia on post-operative ileus (POI) is unknown.

Objective To describe post-operative phosphate dynamics and if hypophosphatemia is associated with POI after a right colon resection.

Design Comparative retrospective cohort study

Settings High-volume tertiary referral center

Patients Patients who underwent right colon resection, which includes right hemicolectomies and ileocolic resections between 2020 and 2022.

Main Outcome Measures POI incidence, post-surgical phosphate dynamics, and post-operative phosphate deficit and recovery.

Results A 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.

Limitations Generalizability of these findings may be limited outside of right colon resections.

Conclusions We 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.

PS serves as a consultant for Ethicon, Medtronic, Olympus, SafeHeal, Karl Storz, and Boston Scientific.

This study did not receive any funding

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

This study was approved by the Mount Sinai Hospital IRB# STUDY-22-00711

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Disclosure: PS serves as a consultant for Ethicon, Medtronic, Olympus, SafeHeal, Karl Storz, and Boston Scientific.

IRB: This study was approved by the Mount Sinai Hospital IRB# STUDY-22-00711

All data produced in the present study are available upon reasonable request to the authors