What is the management of a diabetic coma?

Management of Diabetic Coma

For a patient presenting in diabetic coma, immediately determine whether this is hypoglycemic coma (requiring immediate glucose/glucagon) or hyperglycemic coma from DKA/HHS (requiring fluid resuscitation and insulin), as the treatments are opposite and delays in correct treatment cause preventable mortality. 1, 2

Immediate Assessment and Differentiation

The term "diabetic coma" encompasses two opposite metabolic emergencies that require rapid differentiation:

• Measure blood glucose immediately at bedside to distinguish hypoglycemic coma (glucose <70 mg/dL) from hyperglycemic coma (DKA/HHS with severe hyperglycemia and dehydration) 1, 3
• Do not delay treatment to obtain blood glucose if measurement is unavailable—clinical context usually makes the diagnosis obvious 3, 2
• Hypoglycemic coma typically occurs in insulin-treated or sulfonylurea-treated patients with altered mental status, seizures, or inability to follow commands 3, 4
• Hyperglycemic coma (DKA/HHS) presents with severe hyperglycemia, dehydration, and variable acidosis ranging to profound coma 1

Management of Hypoglycemic Coma

Immediate Treatment Protocol

If the patient is unconscious or unable to swallow safely, administer 1 mg intramuscular glucagon immediately into the upper arm, thigh, or buttocks—this can and should be done by family members or caregivers without waiting for medical personnel. 3

• If IV access is available, administer 10-20 grams of intravenous 50% dextrose immediately, stop any insulin infusion, and recheck blood glucose in 15 minutes 3
• Titrate the dextrose dose based on the initial hypoglycemic value 3
• Never attempt oral glucose in an unconscious patient due to aspiration risk 3
• Do not use buccal glucose as first-line treatment—it is less effective than swallowed glucose and inappropriate for unconscious patients 3

Monitoring and Repeat Dosing

• Recheck blood glucose after 15 minutes 3, 5
• If blood glucose remains below 70 mg/dL, repeat dextrose administration 3
• Continue monitoring every 15 minutes until blood glucose stabilizes above 70 mg/dL 3, 5
• Avoid overcorrection causing iatrogenic hyperglycemia 3
• Once the patient regains consciousness and can safely swallow, immediately give 15-20 grams of oral fast-acting carbohydrates (glucose tablets, regular soft drink, or fruit juice), followed by a meal or snack to prevent recurrence 3, 5

Special Considerations for Sulfonylurea-Induced Hypoglycemia

Hypoglycemic coma due to sulfonylurea overdose always requires hospitalization with prolonged intravenous glucose infusion and careful supervision, as these episodes can be protracted (12-72 hours) due to the long half-life of these medications. 4, 6

• Sulfonylureas have the highest hypoglycemia risk among oral agents 5
• Elderly patients (>60 years), those with renal dysfunction, decreased energy intake, and concurrent infections are at highest risk 6

Management of Hyperglycemic Coma (DKA/HHS)

Initial Resuscitation

The cornerstone of DKA and HHS management is aggressive fluid resuscitation to restore circulatory volume and tissue perfusion—this takes priority over insulin administration. 1, 2

• Management goals include restoration of circulatory volume and tissue perfusion, resolution of hyperglycemia, correction of electrolyte imbalance and acidosis 1
• Individualize treatment based on careful clinical and laboratory assessment, as presentation varies from mild hyperglycemia with acidosis to severe hyperglycemia, dehydration, and coma 1
• Treat any correctable underlying cause such as sepsis, myocardial infarction, or stroke 1

Insulin Administration

• In critically ill and mentally obtunded patients with DKA or HHS, continuous intravenous insulin is the standard of care 1
• For uncomplicated DKA, subcutaneous rapid-acting insulin analogs combined with aggressive fluid management may be used in emergency departments or step-down units—this approach may be safer and more cost-effective than IV insulin 1
• When using subcutaneous insulin, ensure adequate fluid replacement, frequent bedside testing, appropriate treatment of concurrent infections, and appropriate follow-up 1

Transition from IV to Subcutaneous Insulin

Administer basal subcutaneous insulin 2-4 hours prior to stopping intravenous insulin to prevent recurrence of ketoacidosis and rebound hyperglycemia. 1

Electrolyte Management

• Early potassium replacement is essential 2, 7
• Bicarbonate use is generally not recommended, as studies show no difference in resolution of acidosis or time to discharge—reserve for severe acidemia only 1, 2

Fluid Replacement

• Early intensive and adequate intravenous fluid and electrolyte replacement is the most important part of treatment 7
• Main dangers during recompensation include hypovolemia with oliguria/anuria, dysequilibrium syndrome with cerebral edema, and hypokalemia 7

Risk Stratification and Monitoring

High-risk features requiring intensive monitoring include: 3, 5

• History of recurrent severe hypoglycemia or hypoglycemia unawareness
• Concurrent illness, sepsis, hepatic failure, or renal failure
• Recent reduction in corticosteroid dose
• Altered nutritional intake or new nothing-by-mouth status
• Advanced age (>60 years), particularly in hyperglycemic emergencies 7, 6

Post-Event Management

• Any episode of severe hypoglycemia or recurrent episodes requires reevaluation of the diabetes management plan 3, 5
• For unexplained or recurrent severe hypoglycemia, consider admission to a medical unit for observation and stabilization 3, 5
• Patients with hypoglycemia unawareness should raise glycemic targets for at least several weeks to partially reverse unawareness and reduce future risk 1, 5
• Schedule outpatient follow-up within 1 month of discharge; if glycemic medications were changed or glucose control is not optimal, schedule within 1-2 weeks 1

Prevention and Patient Education

• Prescribe glucagon for all patients at increased risk for severe hypoglycemia and ensure caregivers, family members, and school personnel know where it is stored and how to administer it 1, 5
• Educate patients on recognizing early hypoglycemia symptoms and situations that increase risk (fasting, delayed meals, exercise, sleep, alcohol) 1, 5
• Patients should always carry fast-acting glucose sources and wear medical identification indicating diabetes 3
• Implement standardized hospital-wide hypoglycemia treatment protocols, as hospital-related hypoglycemia is associated with higher mortality 5

Common Pitfalls to Avoid

• Failing to differentiate hypoglycemic from hyperglycemic coma before treatment 2
• Attempting oral glucose in unconscious patients 3
• Stopping IV insulin before administering subcutaneous basal insulin in DKA/HHS 1
• Discharging sulfonylurea-induced hypoglycemia patients without prolonged observation 4, 6
• Overlooking elderly patients with multiple risk factors who have substantially higher morbidity and mortality 7, 6