Insulin therapy protocols

Insulin therapy protocols

Insulin therapy protocols

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Pre-Insulin Steps - Laying the Groundwork

DKA Management: IV Fluids, Insulin, and Potassium Protocol

  • Secure 2 large-bore IV lines for aggressive fluid and electrolyte administration.
  • Initial fluid resuscitation is key: infuse 1-1.5 L of 0.9% NaCl (isotonic saline) over the first hour to restore perfusion.
  • Simultaneously, draw initial labs (CMP, ABG/VBG, serum ketones) to establish baseline values, especially for potassium and acidosis.

⭐ The most critical pre-insulin checkpoint is serum potassium. It MUST be > 3.3 mEq/L. Insulin drives K+ intracellularly; administering it during hypokalemia can precipitate life-threatening cardiac arrhythmias.

IV Insulin Protocol - The Main Drip

  • Initiate with IV Regular Insulin: bolus of 0.1 units/kg, then a continuous drip at 0.1 units/kg/hr.
  • Titrate the infusion to achieve a steady glucose decline of 50-75 mg/dL per hour.

⭐ The primary goal of insulin therapy in DKA is to resolve ketosis and close the anion gap, not just to normalize blood glucose. Insulin must be continued even after glucose normalizes, hence the addition of dextrose to prevent hypoglycemia.

Monitoring & Goals - The Watchful Eye

  • Hourly Glucose: Track via fingerstick. Goal ↓ of 50-75 mg/dL per hour.
    • ⚠️ A rapid drop >100 mg/dL/hr increases risk for cerebral edema.
  • Metabolic Panel (BMP): Every 2-4 hours for K+, HCO3-, and anion gap.
  • Anion Gap (AG): Primary marker for resolution. Calculated as $Na^+ - (Cl^- + HCO_3^-)$.
    • Goal: Close the gap to <12 mEq/L.
  • Resolution Criteria: Glucose <200 mg/dL AND two of the following:
    • AG ≤12 mEq/L
    • Bicarbonate (HCO3-) ≥15 mEq/L
    • Venous pH >7.3

⭐ Once blood glucose reaches ~200 mg/dL, add dextrose (D5W) to IV fluids. This prevents iatrogenic hypoglycemia while allowing the insulin drip to continue, which is essential for resolving the underlying ketoacidosis.

The Transition - IV to SubQ Switch

  • Initiate Switch When:
    • Blood glucose < 200 mg/dL
    • AND at least two of the following:
      • Anion gap ≤ 12 mEq/L
      • Serum bicarbonate ≥ 15 mEq/L
      • Venous pH > 7.3
    • Patient is able to tolerate oral intake.
  • Protocol:
    • Administer basal (long-acting) insulin 1-2 hours before discontinuing the IV insulin drip.
    • This overlap prevents rebound hyperglycemia and ketosis.
    • Calculate total daily insulin requirement (e.g., 0.5-0.8 U/kg/day), typically split 50% basal and 50% prandial (bolus).

Exam Favorite: The most common error is stopping the IV insulin infusion simultaneously with the first subcutaneous injection. This creates a gap in insulin coverage, as subcutaneous insulin has a delayed onset, leading to a rapid return to hyperglycemia and ketoacidosis.

High-Yield Points - ⚡ Biggest Takeaways

  • IV regular insulin is the cornerstone of DKA management, typically started with a bolus followed by a continuous infusion.
  • The primary goal is a steady glucose decline of 50-75 mg/dL per hour.
  • Add dextrose (D5W) to IV fluids when serum glucose falls to ~200 mg/dL to prevent hypoglycemia.
  • Continue the insulin drip until the anion gap closes and acidosis resolves.
  • Administer subcutaneous insulin 1-2 hours before stopping the IV infusion to prevent rebound ketoacidosis.

Practice Questions: Insulin therapy protocols

Test your understanding with these related questions

A 27-year-old man with a past medical history of type I diabetes mellitus presents to the emergency department with altered mental status. The patient was noted as becoming more lethargic and confused over the past day, prompting his roommates to bring him in. His temperature is 99.0°F (37.2°C), blood pressure is 107/68 mmHg, pulse is 120/min, respirations are 17/min, and oxygen saturation is 98% on room air. Laboratory values are ordered as seen below. Serum: Na+: 144 mEq/L Cl-: 100 mEq/L K+: 6.3 mEq/L HCO3-: 16 mEq/L BUN: 20 mg/dL Glucose: 599 mg/dL Creatinine: 1.4 mg/dL Ca2+: 10.2 mg/dL Which of the following is the appropriate endpoint of treatment for this patient?

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Flashcards: Insulin therapy protocols

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Do patients with health maintenance organization (HMO) insurance plans require PCP referral for specialist visits?_____

TAP TO REVEAL ANSWER

Do patients with health maintenance organization (HMO) insurance plans require PCP referral for specialist visits?_____

Yes

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