Sodium bicarbonate



Background

  • 8.4% solution contains 1mmol of HCO3-/mL
  • ABC approach to underlying cause ↓pH/toxidrome
  • mmol of HCO3- to correct a NAGMA = 0.3 x weight x -BE

Indications

  • Hyperkalaemia
  • Toxidromes with Na+ channel blockers (e.g. TCADs)
  • Salicylate poisoning (to ↑urinary pH)
  • NAGMA due to bicarb loss (e.g. RTA) i.e. normal anion gap = hyperchloraemia metab. acidosis

Side effects

  • ↑Na+ (1mmol of Na+ per 1mmol of HCO3-)
  • Volume overload
  • ↓K+, ↓Ca++
  • Worse CSF & intracellular acidosis (↑ CO2)
  • ↑lactate (cellular hypoxia)
  • Tissue necrosis ++ if extravasation

Preparation

  • Unless in emergency, dilute prior to admin.

To dilute to 1.26% w/v

  • Remove 75mL from a 500mL bag of 5% dextrose
  • Add 75mL of 8.4% Na+ bicarb. to the remaining 425mL
  • Mix well
  • Regularly check VBG (pH & lactate), U&E (↓K+, ↑Na+) and Ca++


Content by Dr Íomhar O' Sullivan. Last review Dr ÍOS 16/04/22.