Hyperinsulinaemic-euglycemic therapy (HIET)
๐จ HyperinsulinaemicโEuglycaemic Therapy (HIET) is an evidence-based rescue therapy for severe calcium channel blocker (CCB) and beta-blocker (BB) overdose.
It improves cardiac contractility and perfusion without increasing myocardial oxygen demand.
๐ About
- Used in refractory CCB and BB toxicity, especially when conventional therapy (fluids, atropine, glucagon, catecholamines) fails.
- Now considered routine adjunctive therapy in toxicology and critical care settings (ITU/HDU).
โ ๏ธ Side Effects / Monitoring
- Hypoglycaemia ๐ฌ: Insulin drives glucose into cells โ continuous glucose infusion needed.
- Hypokalaemia ๐ปKโบ: Intracellular shift of potassium; replace if severe.
- Hypomagnesaemia / Hypophosphataemia: May occur, monitor electrolytes closely.
- Requires hourly glucose and electrolyte checks in ITU/HDU setting.
๐งฌ Mechanism
- Insulin enhances myocardial carbohydrate uptake and utilisation, improving ATP availability.
- Promotes excitationโcontraction coupling and increases inotropy without raising oxygen demand. ๐ซ
- Benefits:
- Independent of catecholamine signalling โ works even in ฮฒ-blockade.
- Improves contractility ๐ช but not chronotropy (does not increase HR).
- May cause vasodilation โ best used alongside vasopressors if hypotension persists.
๐ Dose (HIET Protocol)
- Loading:
- Give 50 mL of 50% dextrose IV (25 g glucose).
- Administer insulin bolus: 1 unit/kg IV.
- Infusion:
- Dextrose: 50% solution at ~2 mL/kg/hr (โ1 g/kg/hr).
- Insulin: Continuous infusion at 1 unit/kg/hr IV.
- Titrate infusion depending on clinical response.
- Duration: Continue until haemodynamic stability is restored; may need glucose infusion after stopping insulin to avoid rebound hypoglycaemia.
- Setting: Must be delivered in ITU/HDU with invasive monitoring.
๐ References
