Insulin Infusion (Regular)

Dilution guide

Indication

DKA, HHS, hyperkalaemia, post-op glycaemic control.

Preparation

50 units regular insulin in 50 mL 0.9% NaCl (1 unit/mL). Flush 20 mL to saturate tubing.

Dilution

50 U / 50 mL NS → 1 U/mL

Rate

DKA: 0.1 U/kg/h (no bolus). Adjust to glucose fall 50–75 mg/dL/h.

Monitoring

  • Capillary glucose hourly
  • K⁺ q2–4 h
  • Anion gap / ketones
  • Fluid balance

Common errors

  • Stopping insulin before anion gap closes → relapse
  • Hypokalaemia not corrected before insulin start

Pearls

  • Add D5W when glucose <250 mg/dL — don't stop insulin
  • Bridge to subcut overlap by 1–2 h
WardRound

WardRound

Clinical Decisions in Seconds