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The special challenge of patients with diabetic ketoacidosis (Proceedings)
Ketone bodies: acetoacetate, beta hydroxybutyrate, acetone
Pathophysiology
- Ketone bodies: acetoacetate, beta hydroxybutyrate, acetone
- Oxidation of free fatty acids
- Mobilization of fatty acids from adipose tissue
- Shift from fat synthesis to fat oxidation in the liver
- Relative/absolute deficiency in insulin
- Mitigating factor
- elevation in glucose counter-regulatory hormones, especially glucagon
- glucagon:insulin ratio
- metabolic acidosis
- elevations in plasma free fatty acids and amino acid concentrations
- Hyperketonuria enhances osmotic diuresis and electrolyte loss into the urine
- Severe volume depletion
- Severe acidosis
- Pre-renal azotemia
Clinical presentation
- Previously diagnosed diabetes mellitus
- Previous clinical signs of diabetes mellitus
- Anorexia
- Vomiting
- Weight loss
- Tachypneic
- Tachycardic
- Lethargy
- Depression/obtundation
- Poor perfusion, weak pulses, pale mm
- Hypotension
Initial Diagnostic Assessment
- PCV/TS/AZO/DEX
- Na, K, UA (dipstick and S.G.), serum ketones
- Osmolality, blood gas
- CBC, Chemistry, Urinalysis, Urine culture
Diagnosis
- Hyperglycemia
- Glucosuria
- Ketonemia
- Ketonuria
Clinical Pathologic Abnormalities
- Elevated WBC +/- left shift if pancreatitis or underlying infection
- Elevated liver enzymes
- Icterus in some cats
- Azotemia, pre renal
- Sodium concentration normal/low
- Potassium concentration normal/low
- Acidosis
- Bacteriuria, pyuria
Treatment (in order of importance)
- Fluid Therapy
- Correct hypovolemia and poor perfusion
- Combat lactic acidosis
- Correct electrolyte abnormalities
- Preserve cardiac output and renal perfusion
- Dilute hyperglycemia
- 0.9% NaCl +/- potassium
- Potassium Replacement
Serum K (mEq/L)
KCl/L (mEq)
Maximum rate (mL/kg/h)
3.6-5.0
20
24
3.1-3.5
30
16
2.6-3.0
40
11
2.1-2.5
60
8
<2.0
80
6
- Insulin Therapy
- Rregular crystalline insulin
- 2.2 U/Kg/24 hr (dog); 1.1 U/kg/24 hr (cat) IV in separate IV bag
- CRI Insulin Therapy using Regular, Crystalline Insulin
Glucose (mg/dL)
Fluid
Insulin rate (2.2 U/kg in 250 ml) mL/hr
>250
0.9% NaCl
10
200-250
0.45% NaCl + 2.5% dextrose
7
150-200
0.45% NaCl + 2.5% dextrose
5
100-150
0.45% NaCl + 5% dextrose
5
<100
0.45% NaCl + 5% dextrose
Stop infusion
- Intermittent IM insulin technique with regular insulin
- 0.2 U/kg IM initially
- 0.1 U/kg IM hourly until blood glucose < 250 mg/dl
- Regular insulin SQ 0.5-1 U/kg q 4-6 hours after patient hydration achieved
- Bicarbonate Therapy
- Only give initially if pH < 7.0
- Otherwise wait to see if reperfusion will correct acidosis
- 0.1 x base deficit x BW(kg); add slowly over 2 hours – only 1/3 replacement amount to prevent overcorrection
- Phosphorous Therapy
- patients will often get hypophosphatemic within 1-3 days after initiation of therapy
- can cause myopathies, hemolysis, encephalopathy
- 0.01-0.03 mmol phosphate/kg/h over 6 hours and recheck
- Magnesium Therapy
- Often worsens with initial treatment
- 2. Difficult to correct other electrolyte abnormalities until hypomagnesemia is addressed
- 0.75-1.0 mEq/kg/day IV in 5% dextrose for 24-48 hours
Initiation of Longer Acting Insulin
- Dehydration corrected
- Animal eating/drinking normally
- Electrolyte abnomralities corrected