Page 567 - Cote clinical veterinary advisor dogs and cats 4th

Diabetic Ketoacidosis 255

may be treated with long-acting insulin. The short-acting insulin in the acute treatment Possible Complications
following discussion pertains to patients with phase. Give as an intravenous constant-rate • Hypoglycemia secondary to insulin overdose
VetBooks.ir of treatment. Restoration of perfusion and glucose concentration, or as intermittent • Electrolyte deficiencies: monitor electrolytes Diseases and Disorders
or lack of dextrose supplementation: monitor
infusion (CRI), adjusted based on patient
DKA. Intravenous fluid therapy is the mainstay
blood glucose q 1-4h to avoid.
intramuscular doses. Start insulin only
hydration should begin as soon as possible.
Acute General Treatment after initial rehydration and correction of q 4-12h, depending on severity. Supplement
aggressively based on bloodwork findings.
electrolytes have been started.
• Address perfusion deficits immediately with a ○ For an insulin CRI: add 1 U/kg (cat) or Potassium supplementation should not
10-20 mL/kg IV bolus of an isotonic crystal- 2 U/kg (dog) regular insulin to a 250-mL exceed 0.5 mEq/kg/h.
loid such as Normosol-R, lactated Ringer’s bag of 0.9% NaCl. • Hemolytic anemia can occur due to hypophos-
solution, or 0.9% NaCl. Reassess perfusion ○ Measure blood glucose concentration q phatemia (serum phosphorus < 1.5 mEq/L).
parameters immediately after bolus and at 1-2h, and adjust insulin rate depending • Rarely, neurologic signs occur from rapid
15-minute intervals until stable. Repeat bolus on blood glucose. decreases in sodium and glucose. Monitor
therapy as necessary. ○ When the blood glucose concentra- blood glucose q 1-4h and sodium q 4-12h
• Continue intravenous fluid therapy with an tion drops below 250 mg/dL, dextrose to ensure a slow, gradual drop in both. The
isotonic crystalloid at a rate calculated to supplementation is necessary to avoid goal is a drop in blood glucose concentration
include maintenance, dehydration deficit, hypoglycemia. < 50-100 mg/dL/h.
and ongoing losses. Correct the dehydration
over 6-12 hours, or slower if cardiac disease is Percent Recommended Monitoring
present. To calculate the dehydration deficit, Blood Glucose Insulin Dextrose • Aggressive monitoring is necessary during
use this formula: percentage dehydration (as Level (mg/dL) CRI in Fluids the acute phase of therapy for DKA. Severe
a decimal) × body weight (kg) × 1000 mL/ >250 10 mL/h None cases require 24-hour care.
kg. 200-250 7 mL/h 2.5% ○ Monitor blood glucose concentration q
• Adjust fluid rate to maintenance plus ongoing 150-200 5 mL/h 2.5% 1-4h.
losses after correction of dehydration. Reas- 100-150 5 mL/h 5% ○ Monitor electrolyte concentrations, includ-
sess hydration at least q 12h. <100 None 5% ing sodium, potassium, phosphorus, and
• Electrolyte supplementation is also crucial. • The intramuscular protocol is less labor magnesium, q 4-12h.
○ Correct hypokalemia with potassium intensive. Give 0.25 U/kg IM q 4h. The ○ Monitor serum or urine ketones q 24h.
chloride supplementation (p. 495). insulin dose and dextrose concentration ○ Monitor hydration status, including body
○ Dilute potassium chloride in the crystal- should be adjusted based on blood glucose weight, q 6-12h.
loid solution being given intravenously, concentration as for the CRI protocol. ○ Depending on severity of clinical signs
using the table below. • Consider glargine insulin in cats; give and concurrent disease processes, consider
○ The final rate should not exceed 0.5 mEq/ 0.25 U/kg SQ q 12h in addition to 1 U monitoring of blood pressure, electro-
kg/h. If initial serum potassium concentra- IM up to q 6h if the blood glucose level is cardiogram, pulse oximetry, packed cell
tion is normal, assume it will drop with > 250 mg/dL. This protocol allows owners volume, and urine output.
fluid and insulin therapy, and begin potas- to use the same vial of insulin at home as
sium supplementation with 20 mEq/L. in the hospital. PROGNOSIS & OUTCOME
○ Recheck potassium q 4-12h initially, • Treat any concurrent disease process specifi-
depending on severity. cally, if possible; otherwise treat supportively. • The majority of dogs (≈70%) and cats
• Sodium bicarbonate supplementation is rarely (≈60%) survive to discharge.
Serum mEq KCl Added warranted because acid-base abnormalities • In dogs, concurrent hyperadrenocorticism is
Potassium per 1 L of Fluid typically resolve with other therapies. associated with a worse prognosis, as are low
3.5-5 20 calcium (total or ionized) concentrations,
3.0-3.4 30 Chronic Treatment anemia, and low venous pH at presentation.
2.5-2.9 40 • After the patient is alert, eating, and drink- • In cats, poor outcome is associated with azo-
2.0-2.4 60 ing; blood glucose is relatively controlled; temia and hyperbilirubinemia at presentation.
<2.0 80
and ketosis has resolved, start a long-acting
○ Correct hypophosphatemia if serum con- insulin (p. 251). PEARLS & CONSIDERATIONS
centration is < 1.5 mg/dL with potassium • If using a CRI, it should be stopped for
phosphate 0.01-0.12 mM/kg/h IV. Take approximately 4 hours before beginning Comments
into account the potassium contained in maintenance insulin therapy. • Patients often require high rates of fluid for
potassium phosphate (4.4 mEq/mL) when rehydration and maintenance of hydration.
calculating total potassium requirements to Nutrition/Diet • If urine cannot be obtained due to dehydra-
avoid oversupplementation. A simple way • If the patient is anorectic in the hospital, tion, use serum to test for ketones.
to do this is to calculate total potassium place a short-term feeding tube such as
requirement and give one-half as potas- a nasoesophageal or nasogastric tube to Technician Tips
sium phosphate and one-half as potassium facilitate nutrition (p. 1107). Forced oral • To facilitate frequent blood draws, place a
chloride. feeding is not recommended. sampling catheter in a central or peripheral
○ Correct hypomagnesemia if serum • Once eating, dietary recommendations are vein.
concentration is < 1.2 mg/dL; use mag- the same as for chronic therapy of DM • Patients require intensive monitoring of
nesium sulfate 0.5-1 mEq/kg/day added (p. 251). mentation, fluid balance, pain, and other
to intravenous fluids. health parameters.
○ Monitor electrolytes at least q 12h or Drug Interactions
more frequently, depending on severity • Insulin should be given through a dedicated SUGGESTED READING
of imbalance. IV catheter to avoid an inadvertent bolus. Koenig A: Endocrine emergencies in dogs and cats.
• Insulin therapy is necessary to decrease blood • Because insulin may adhere to the admin- Vet Clin Small Anim 43:869-897, 2013.
glucose concentration and stop the forma- istration set, run ≈50 mL of insulin-saline
tion of ketone bodies. The goal is a blood solution through the tubing (i.e., waste AUTHOR: Lenore Bacek, DVM, MS, DACVECC
EDITOR: Ellen N. Behrend, VMD, PhD, DACVIM
glucose level of 100-250 mg/dL. Use regular, 50 mL) before use.
www.ExpertConsult.com