Usually from vomiting/NG losses, diuretics or post-hypercapnia. Urine chloride separates chloride-responsive (< 20 mmol/L) from chloride-resistant causes. Treat with chloride, potassium and volume; acetazolamide if overloaded.
At the bedside
Timed steps- 1
Common ICU causes
CauseNG drainage, vomiting, loop/thiazide diuretics, post-hypercapnic (after ventilating chronic CO2 retainers), citrate (massive transfusion, CRRT), hypokalaemia, steroids/mineralocorticoid excess.
- 2
Urine chloride
Test< 20 mmol/L = chloride-responsive (vomiting, past diuretics). > 40 mmol/L = current diuretics, mineralocorticoid excess, severe hypokalaemia, Bartter/Gitelman.
- 3
Chloride-responsive
Treat0.9% saline if volume-depleted, KCl to K+ ≥ 4; PPI for ongoing NG loss.
- 4
Overloaded
TreatAcetazolamide 250-500 mg IV once or twice daily (watch K+); reduce loop diuretic; KCl.
- 5
pH > 7.55-7.6
SevereConsider dilute HCl (central line) or dialysis with low-bicarbonate bath (rare).
Metabolic alkalosis
Step 1 of ~3
Decision: Urine chloride < 20 mmol/L?
Based on Luke RG, Galla JH. Educational use; follow local protocol.
Evidence
- Luke & Galla 2012: chloride depletion maintains alkalosis; chloride repletion corrects it.
🇮🇳 India notes
- Hypokalaemic metabolic alkalosis with high urine chloride and normal BP in young adults: consider Gitelman syndrome or surreptitious diuretic use.
References
Test yourself
Module quiz · score 70% to complete the module
Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.