A decade of progress: Declining readmissions for dehydration and acute kidney injury after bariatric surgery

Dehydration and acute kidney injury are leading causes of readmission following bariatric surgery. Although the overall bariatric surgical safety profile has improved substantially, national trends in readmissions specifically attributed to dehydration and acute kidney injury remain unknown. The objective of our study was to evaluate national trends in postoperative readmissions because of dehydration and acute kidney injury among bariatric surgical patients.

The Metabolic and Bariatric Accreditation and Quality Improvement Program database was queried to identify patients who underwent primary minimally invasive sleeve gastrectomy or Roux-en-Y gastric bypass between 2015 and 2023. The primary outcome was 30-day readmission for dehydration/acute kidney injury, defined by Metabolic and Bariatric Accreditation and Quality Improvement Program readmission codes for "nausea, vomiting, fluid, electrolyte and nutritional depletion," "renal insufficiency," and "renal failure." Annual readmission rates were calculated by procedure type. Multivariable regression analysis was used to identify associated factors.

A total of 1,456,480 patients were included; 73.2% underwent sleeve gastrectomy. Mean age was 44 years; mean body mass index was 45.2 kg/m². The overall readmission rate was 3.3%, of which 28.0% were for dehydration/acute kidney injury. Readmission rates because of dehydration/acute kidney injury declined significantly for both sleeve gastrectomy (1.2%-0.5%; P < .0001) and Roux-en-Y gastric bypass (1.8%-0.9%; P < .0001). On multivariable analysis, undergoing sleeve gastrectomy, female sex, and Non-Hispanic Black race were associated with significantly higher odds of readmission. Comorbidities, such as insulin-dependent diabetes, hypertension, and renal insufficiency, were also independently associated with increased odds of readmission.

Readmissions for dehydration/acute kidney injury decreased by more than 50% between 2015 and 2023 among primary bariatric surgical patients. Despite this global improvement, patient- and procedure-related factors confer persistently elevated readmission risk, identifying high-risk patient populations and the need for targeted preventative strategies.