Tacrolimus Aggravated Tube Feeding Syndrome with Acute Renal Failure in a Pediatric Liver Transplant Recipient

Table 3

The patient’s calculated water deficit over the last 8 days prior to admission to the pediatric intensive care unit.

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Equations

Water intake = food intake × water content

Water requirement = (food intake × potential renal solute load/age dependent estimated maximal renal concentration capacity) + (insensible water losses × patient’s body surface area)

Water deficit = water intake − water requirement

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Case specific calculations

Water intake per day = 0.8 L/day × 0.77 L/L = 0.616 L/day

Water requirement per day = (0.8 L/day × 374 mOsmol/L/465 mOsmol/L) + (0.5 L/day/sqm × 0.4 sqm) = 0.843 L/day

Water deficit per day = 0.616 L/day − 0.843 L/day = −0.227 L/day

Water deficit within 8 days = 1.820 L

Percent of body weight = 1.820 L/7.7 kg⁡23.6%

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Potential renal solute load (PRSL) refers to solutes of dietary origin that would need to be excreted in the urine if none were diverted into synthesis of new tissue or lost through nonrenal routes. It is calculated by the following equation: PRSL = nitrogen/28 + sodium + chloride + potassium + phosphorus. The units are in milliosmoles, except for nitrogen, which is total nitrogen in milligrams. Available phosphorus is assumed to be total phosphorus of milk-based formulas and two-thirds of the phosphorus of soy-based formulas. PRSL is expressed as milliosmoles per liter [3]. The renal concentration capacity on admission was 465 mOsmol/L. The insensible fluid losses under normal condition are 0.5 L/sqm/day [4].