Emergency Management for Diabetic Pets

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar syndrome (HHS) are the 2 most significant emergency complications in diabetic veterinary patients. Both conditions result from a relative insulin deficiency and have similar pathophysiologic mechanisms and clinical presentations. Increased gluconeogenesis, accelerated glycogenolysis, and impaired tissue glucose use collectively result in hyperglycemia, starving the body’s cells and shunting toward free fatty acid (FFA) use as a primary energy source. Increased numbers of counter-regulatory hormones (including cortisol, epinephrine, growth hormone, and particularly glucagon) contribute to disease pathogenesis. Two hypotheses explain the lack of ketonemia in HHS: (1) insufficient insulin to counter hyperglycemia but adequate insulin to limit lipolysis, or (2) lower FFA concentrations, increased portal vein insulin concentrations, or both. DKA patients may clinically present with normoglycemia or hyperglycemia, while HHS patients typically demonstrate serum glucose concentrations of > 600 mg/dL. DKA patients also have variable serum osmolality, while HHS patients are hyperosmolar by definition with elevated morbidity and mortality rates. Although rare, HHS patients have an increased risk for cerebral edema and neurologic complications secondary to extensive fluid losses and severe hyperosmolality. HHS patients should be resuscitated over longer time periods than DKA patients to aim for gradual changes in blood glucose and electrolytes. Current recommendations for insulin therapy favor continuous infusion rates rather than intermittent intramuscular injections due to variable injection absorption in dehydrated patients. Replacement of potassium, phosphorus, and magnesium are important during therapy. Anemia secondary to oxidative stress and seizures due to cerebral injury worsen the prognosis. Mortality rates range from 26% to 30% in DKA patients and 65% in HHS patients, and often depend on the presence of concurrent illness.

Commentary: This excellent summary describes 2 challenging diseases and helpful therapeutic guidelines. It is common to bolus fluids during resuscitation of patients in shock prior to diagnosis. This review reinforces the concept that cautious administration of fluids and careful attention to glucose, acid–base status, and electrolyte derangements are important when treating these diseases.

Diabetic emergencies in small animals. O’Brien MA. Vet Clin N Am Small Anim Pract 40:317-333, 2010.