Hypoglycemia associated with refeeding syndrome in a cat.

Abstract

Companion Notes

Case report of hypoglycemia associated with refeeding syndrome in a cat

- hypoglycemia is a complication common in people; not previously reported in a cat

Overview on refeeding syndrome (RFS)

- occurs after food is reintroduced after a period of starvation or fasting

- involves fluid and electrolyte shifts as well as metabolic abnormalities

- the individual animal’s response varies and is unpredictable

- common complications during refeeding include the following:

- hypophosphatemia

- hypokalemia

- hemolytic anemia

Case report of a 2-year-old, 3.22 kg (previously 6.2 kg), neutered, sex:M DSHcat

- presentation after being found weak and recumbent in neighbor’s garage

- cat had been missing for 12 weeks

- physical examination: minimally responsive and recumbent

- dehydration, 10%

- body condition score: 1 of 9

- muscle atrophy, marked

- hypothermia at 34.4°C (94°F)

- bradycardia at 120 bpm

- abundant flea dirt in hair coat

- treatment: heat lamp attached to cage door (temp 37.9°C after 4 hours)

- mini stat panel

- hypernatremia at 171.9 mmol/L with reference at 146-156 mmol/L

- hypokalemia at 3.53 mmol/L with reference at 3.8-5.1 mmol/L

- hyperglycemia at 13.2 mmol/L with reference at 4.4-7 mmol/L

- elevated BUN at > 35.7 mmol/L with reference at 2.5-9.3 mmol/L

- elevated creatinine at 150.3 µmol/L with reference at 53-123.8 µmol/L

- CBC and biochemistry: (hemolysis noted in serum)

- hyperbilirubinemia, mild at 10.26 µmol/L with reference at 1.7-6.84

- elevated BUN at 56.8 mmol/L with reference at 5-13 mmol/L

- creatinine normal

- hyperglycemia at 12.7 mmol/L with reference at 3.6–9.4 mmol/L

- hypernatremia at 178 mmol/L with reference at 145-158 mmol/L

- neutrophilic leukocytosis with left shift

- neutrophilia at 14.525 × 10⁹/L with reference at 2.5-8.5 × 10⁹/L

- bands at 525 × 10⁹/L with reference interval at 0-0.15 × 10⁹/L

- anemia, normocytic, normochromic (Hct at 15% with RI at 29-48%)

- urine specific gravity: 1.026

- negative FeLV and FIV serology

- treatment

- balanced electrolyte solution, 2.5 mL/kg/h

- supplemented with 20 mmol/L potassium chloride

- cat began to start to lift head within an hour

- increased to 3.7 mL/kg/hr after pRBCs

- packed red blood cells (pRBCs) (2 hours later PCV at 21%)

- nitenpyrum, 11.4 mg PO

- famotidine, 0.5 mg/kg sc

- sucralfate, 47 mg/kg q12h PO

- cat’s resting energy requirement (RER) calculated to be 166 kcal per day

- authors planned to gradually increase caloric intake daily

- unless nausea, vomiting, or diarrhea developed

- 8 hours after presentation

- food offered and cat readily ate 18 grams (12% RER)

(low carbohydrate canned diet)

- 18 grams eaten 6 hours later (another 12% RER)

- 12 hours after presentation, hypernatremia and hypokalemia improved

- hyperglycemia resolved, BUN improved and creatinine normal

- hyperthermia at 40°C despite removing heat lamp

- hypophosphatemia had developed at 1.1 mg/dL with reference at 2.4-8.2

- IV fluids supplemented with 13.6 mmol/L phosphorus

- day 2; cat’s weight up to 3.42 kg; temperature varied between 39.3-40°C

- hypophosphatemia persisted

- IV fluids supplemented to 45 mEq/L K⁺ and 67.5 mmol/L PO₄^-

- hypoglycemia developed (66 mg/dL on stat panel; 51 mL/dL on glucometer)

- IV fluids supplemented with dextrose 50%

- to provide constant rate infusion (CRI) of 5% dextrose

- glucose at 125 mg/dL 4 hours later

- dextrose CRI provided 44.2 kcals over 28 hours or 27% RER

- thiamine, 2.0 mg given PO in vitamin and mineral supplement

- thiamine deficiency is common after starvation

- day 3; temperature varied between 38.9-39.5°C

- serum hemolysis persisted (iron dextran, 19.1 mg/kg IM)

- IV fluids continued at 3.5 mL/kg/h

- K⁺ at 65 mEq/L and PO₄^- at 67.5 mmol/L and 5% dextrose

- serum phosphorus increased to 2.9 mEq/dL

- hypokalemia and hypernatremia resolved

- normoglycemia maintained

- outcome day 7: cat discharged

- recheck 2 weeks later: normal CBC and biochemistry:

- outcome 22 months post-discharge: cat clinically normal

“At this time, there are no evidence-based studies demonstrating the ideal refeeding strategy. Recommendations have been made to provide most calories as fat and protein because carbohydrates stimulate more insulin release and thus may result in more severe metabolic derangements…; however, ideal carbohydrate proportion has not been determined.”