## Management of DKA: Insulin Therapy ### Rationale for IV Regular Insulin **Key Point:** In diabetic ketoacidosis, intravenous regular insulin is the drug of choice because it provides rapid onset, short half-life (~6 minutes), and allows for real-time titration based on glucose and ketone response. **High-Yield:** The initial bolus dose is 0.1 unit/kg IV, followed by continuous infusion at 0.1 unit/kg/hour. Insulin works by: - Suppressing hepatic ketogenesis - Enhancing peripheral glucose utilization - Inhibiting lipolysis (the source of free fatty acids for ketone production) ### Why IV Regular Insulin Over Alternatives | Feature | IV Regular Insulin | Insulin Glargine | Insulin Lispro SC | Metformin | |---------|-------------------|------------------|-------------------|----------| | **Onset** | 15 minutes | 1–2 hours | 15–30 minutes | Hours to days | | **Half-life** | ~6 minutes | ~24 hours | ~1 hour | N/A | | **Titratability** | Excellent (real-time) | Poor (long-acting) | Moderate | N/A | | **Ketone suppression** | Rapid & reliable | Delayed | Slower | Ineffective | | **Route in DKA** | IV (standard) | SC (contraindicated) | SC (suboptimal) | Contraindicated | **Clinical Pearl:** Insulin suppresses ketogenesis by inhibiting hormone-sensitive lipase in adipose tissue, reducing the flux of free fatty acids to the liver. This is why insulin is essential — glucose control alone is insufficient to stop ketone production. **Mnemonic: DRIP** — **D**ose (0.1 unit/kg bolus), **R**egular insulin, **I**ntravenous, **P**erfusion (continuous). ### Concurrent Management - Fluid resuscitation (0.9% saline) to restore intravascular volume and GFR - Potassium replacement (monitor closely; insulin shifts K⁺ intracellularly) - Bicarbonate (only if pH < 6.9 and life-threatening arrhythmias) - Phosphate replacement if depleted [cite:Harrison 21e Ch 397]
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.