Emergency Management of the Sick Diabetic
By: Stephanie Harrier, DVM, Emergency Clinician
Veterinary Specialty & Emergency Center
Diabetic ketoacidosis (DKA) is one of the most common endocrine diseases seen at the Veterinary Specialty and Emergency Center. The majority of these pets are new diabetics on presentation, however many DKA patients are long term, well managed diabetics. The common presenting complaints of these pets are polyuria, polydipsia (or adipsia), lethargy and vomiting. The majority of these pets have concurrent disease, such as pancreatitis, urinary tract infections and hyperadrenocorticism.
A full diagnostic workup including a complete blood count, serum chemistry, venous blood gas, PCV/TS, urinalysis and urine culture, abdominal ultrasound and thoracic radiographs should be considered in all patients who present in DKA. By definition patients diagnosed with DKA will have a metabolic acidosis, hyperglycemia, and be ketotic. Other common laboratory abnormalities include electrolyte derangements, elevations in liver enzymes and azotemia. Increased liver enzymes can be attributed to hepatic lipidosis, pancreatitis, and/or hypovolemia. Azotemia is typically pre-renal in origin but can have a renal component. These values tend to normalize in patients after appropriate therapy. After therapy is initiated, serum electrolytes and blood glucose should be serially monitored.
Fluid therapy is essential in patients with DKA, as many present in hypovolemic shock. Normal saline was once advocated as the fluid of choice however any isotonic fluid, including LRS, Normosol-R, and Plasmalyte, are appropriate choices. Fluid boluses should be administered until the patient’s blood pressure, heart rate and other vital signs have normalized. The remainder of the patient’s fluid deficit (BW (kg) x % dehydration x 1000 = mL of fluid deficit) should be corrected over 12-24 hours. Consider the use of a central venous pressure to monitor for fluid overload, especially in those patients with known or suspected heart disease.
Potassium, phosphorous, and magnesium are electrolytes that most commonly require supplementation in pets treated for DKA. Potassium supplementation should be started within two hours of initiating fluid therapy. A minimum of 40 mEq KCl/L is typically required but adjustments should be made based on serial electrolyte monitoring using the guidelines in “table 1”, below.
Once insulin therapy is initiated, phosphorus and magnesium should be monitored. Refractory hypokalemia may be due to hypomagnesemia (iMg <0.2mmol/L) in which case magnesium is supplemented at a dose of 0.5 mEq/kg/day. Phosphorus is supplemented at a dose of 0.01 – 0.06 mmol/kg/hr if serum phosphorus is <2.5 mg/dL. Bicarbonate therapy is rarely indicated as the metabolic acidosis resolves with fluid therapy in most cases. However, its use is necessary if the patient is persistently acidotic (blood pH <7.1) If bicarbonate is used, it is recommended to give ¼ to ⅓ of the calculated dose (mL bicarbonate = 0.1 x BW (kg) x (4- HCO3) ) over a two hour period then recheck a blood gas.
Insulin therapy is started four to eight hours after fluid therapy. Regular insulin is administered either as a CRI or by intermittent intramuscular injections based on serial blood glucose measurements. Care needs to be taken to not decrease blood glucose by more than 75-100 mg/dL/hr to avoid the complications of osmotic disequilibrium on the brain. Regular insulin is administered until ketosis has resolved and the patient is eating well. At that time the patient is started on an appropriate dose of long acting insulin. See Tables 2 and 3 for regular insulin dosing.
All other concurrent diseases should be treated appropriately. For instance, antibiotics for suspected or confirmed urinary tract infection and antiemetics and analgesics for pancreatitis.
Table 1 – Potassium Supplementation
|Potassium mEq/L||mEq KCl added to 1 L fluids||Maximum IVF rate (mL/kg/hr)|
Table 2 – Intravenous Regular Insulin CRI
|Blood Glucose (mg/dL)||Rate of Insulin||% Dextrose in Fluids|
|<100||Stop CRI||5% +/- 0.5 g/kg dextrose bolus|
*For cats add 1.1 U/kg of regular insulin to a 250 mL bag of 0.9% NaCl. For dogs at 2.2 U/kg of regular insulin to a 250 mL bag of 0.9% NaCl. Discard 50 mL through IV tubing. Blood glucose is monitored q1-2 hours.
Table 3 – Intermittent Intramuscular Regular Insulin
|Blood Glucose (mg/dL)||Dose of Insulin||% Dextrose in Fluids|
|<100||0||5% +/- 0.5 g/kg dextrose bolus|
*Monitor blood glucose q4 hours
**References available upon request**
Dr. Stephanie Harrier is an emergency clinician at the Veterinary Specialty & Emergency Center. The Veterinary Specialty & Emergency Center operates state-of the-art emergency and specialty veterinary hospitals that are open 24/7/365 in both Levittown PA and Philadelphia PA. For more information about our world-class emergency and specialty care, please visit VSEC on the web at www.VSECVET.com.