Intermittent boluses of balanced salt solution for post-operative intravenous hydration following elective major abdominal and thoracic surgery in children

Purpose Maintenance fluids following major operations in children are typically administered with a continuous rate. We hypothesized that administering fluids as intermittent boluses is more physiologic and could limit post-operative fluid volume, thereby avoiding harmful effects of excess fluid. Methods We retrospectively reviewed children aged 1–21 admitted after an elective major abdominal or thoracic operation from 2015 to 2021. We excluded non-elective operations and patients receiving peri-operative enteral or parenteral nutrition. We analyzed total fluid volume at 0–24, 24–48, 48–72, and 72–96 h, time to regular diet and discharge, and end-organ complications. Results We identified 363 patients, of which 108 received intermittent boluses and 255 continuous fluids. Bolus group patients received significantly less fluid up to 72 h post-operatively with average rates of 0.49 mL/kg/h vs 0.86 mL/kg/h at 0–24 h ( p << 0.01), 0.57 mL/kg/h vs 1.46 mL/kg/h at 24–48 h ( p << 0.01), and 0.50 vs 0.92 mL/kg/h at 48–72 h ( p << 0.01). Additionally, the bolus group maintained adequate urine output, tolerated a regular diet sooner (2.08 days vs 2.51 days; p = 0.0023) and averaged a shorter hospital stay (3.12 vs 4.14 days; p = 0.004). There was no difference in adverse effects between the two groups. Conclusion Utilizing intermittent boluses reduces the volume of maintenance fluids administered and may lead to a faster time to regular diet and discharge. Level of evidence IV. Type of study Retrospective review.