Surgical Critical Care: Diabetic Ketoacidosis (DKA)
Diabetic Ketoacidosis (DKA)
Definitions
- Hyperosmolar Hyperglycemic State (HHS) – Hyperglycemia & Hyperosmolar Plasma but No Acidosis or Ketonemia
- Also Known As: Hyperosmotic Hyperglycemia Nonketotic State (HHNK)
- Diabetic Ketoacidosis (DKA) – Hyperglycemia with Acidosis & Ketonemia
Pathogenesis
- Primary Factors:
- Insulin Deficiency & Resistance
- Glucagon Excess (From Loss of Normal Inhibitory Effects of Insulin)
- Hyperglycemia Generated By:
- Impaired Peripheral Glucose Utilization
- Increased Gluconeogenesis in Liver & Kidney
- Increased Glycogenolysis
- Ketone Production:
- When Cells Unable to Use Glucose, Lipolysis Generates Fatty Acids
- Fatty Acids Cause Ketones Production Through the Krebs Cycle
- Ketones Then Provide Alternative Source of Energy for Peripheral Tissues
- Acidosis:
- From Production of β-Hydroxybutyric & Acetoacetic Acids
- Potassium Derangement:
- Large Total Potassium Deficit – Largely from Urinary Loss (Glucose Osmotic Diuresis & Excretion of Potassium Ketoacid Anion Salts)
- False Elevation in Labs Due to Extracellular Shift from Hyperosmolarity & Insulin Deficiency
Triggering Events
- Infection (PNA/UTI)
- New-Onset Diabetes Type 1
- Insufficient Insulin Therapy
- Surgery
- Myocardial Infarction
- Stroke
- Pancreatitis
Presentation
- Polyuria
- Polydipsia
- Weight Loss
- Dehydration
- Neurologic Symptoms (Lethargy, Obtundation & Coma)
- Hyperventilation
- “Fruity Odor” to Breath (From Acetone Exhalation)
- Abdominal Symptoms (Pain, Nausea & Vomiting)
DKA/HHS Comparison
- Diabetic Ketoacidosis (DKA)
- Acidosis & Ketonemia
- Hyperventilation & Abdominal Symptoms More Common
- More Common in Young (< Age 65)
- Glucose Generally 300-500 mg/dL
- Hyperosmolar Hyperglycemic State (HHS)
- No Acidosis or Ketonemia
- Neurologic Symptoms More Common (Due to Higher Osmolarity)
- More Common in Old (> Age 65)
- Glucose Often > 1,000 mg/dL
American Diabetes Association Classification
- Often Significant Overlap Between Syndromes
| Mild DKA | Moderate DKA | Severe DKA | HHS | |
| Glucose (mg/dL) | > 250 | > 250 | > 250 | > 600 |
| Glucose (mmol/L) | > 13.9 | > 13.9 | > 13.9 | > 33.3 |
| Arterial pH | 7.25-7.30 | 7.00-7.24 | < 7.00 | > 7.30 |
| Bicarbonate | 15-18 | 10-15 | < 10 | > 18 |
| Urine Ketones | Positive | Positive | Positive | Small |
| Serum Ketones (Nitroprusside Reaction) | Positive | Positive | Positive | Small |
| Serum Ketones ( β-Hydroxybutyrate) | 3-4 mmol/L | 4-8 mmol/L | > 8 mmol/L | < 0.6 mmol/L |
| Serum Osmolarity | Variable | Variable | Variable | > 320 |
| Anion Gap | > 10 | > 12 | > 12 | Variable |
| Mental Status | Alert | Drowsy | Stupor/Coma | Stupor/Coma |
Diagnosis/Labs
- Diagnosis Based Primarily on Labs
- High Glucose
- High Anion Gap Metabolic Acidosis
- High Urine Ketones (Acetoacetic Acid, β-Hydroxybutyrate & Acetone)
- Low Na
- Normal-High K (Falsely Elevated Despite Large Total Body Losses)
- May See Large Potassium Shifts with Early Resuscitation
Treatment
- Primary Tx: IV Fluids, Electrolyte Correction & Insulin
- Fluid Resuscitation:
- Generally Start with 0.9% or 0.45% NS
- Once Serum Glucose Reaches 200 mg/dL: Switch to D5 0.45% NS
- If K < 3.3 mEq/L: Delay Insulin Administration Until K > 3.3 mEq/L