Metabolic Alkalosis DDx

  • Metabolic changes that result in the accumulation of base
  • Accumulation of base occurs as a result of
    • Increased acid loss
    • Excess alkali intake

Causes

  • GIT excess acid loss
    • Vomit (and pyloric stenosis)
    • NGT drainage
    • Diarrhoea
    • Ileostomy
    • Dehydration
  • Renal excess acid loss
    • Bartter syndrome
    • Gitelman syndrome
    • Diuretics (Loss of H+, K+, Cl-)
  • Overdose of base
    • Antacid OD, Laxative, Milk-alkali syndrome
    • Massive Hartmann’s transfusion
    • Iatrogenic use of HCO3
  • Endocrine
    • Cushing syndrome
    • Steroid excess
    • Hyperaldosteronism

Clinical

  • Shift O2 dissociation curve to left (increased affinity for Hb-O2)
    • Right shift with increase TEMP, 2-3 DPG, H+
  • Hypokalaemia, hypocalcaemia, hypochloraemia
  • Symptoms related to HYPOcalcaemia and HYPOkalaemia
    • Dizzy, light-headed
    • Chest tightness
    • Anxiety, dysphasia…..laryngospasm

Correction

  • Correct underlying problem
  • Improve renal bicarbonate excretion (Cl, K and volume)
  • Correct electrolyte imbalance
  • Oxygen
  • Avoid hyperventilation
  • Rarely, acetazolamide or HCl infusion

References and Links


CCC 700 6

Critical Care

Compendium

Emergency physician MA (Oxon) MBChB (Edin) FACEM FFSEM with a passion for rugby; medical history; medical education; and informatics. Asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | vocortex |

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