Sodium Bicarbonate

The factor 0.2 corresponds to the proportion of extracellular fluid in relation to total body weight. SPC worked example: in a patient of 70 kg with a base deficit of 5 mmol/l, 5 x 70 x 0.2 = 70 mmol of sodium bicarbonate (equivalent to 70 ml of Sodium Bicarbonate 8.4% w/v) are to be given — i.e. 1 mmol corresponds to 1 ml of the 8.4% w/v solution. URINE ALKALINISATION: the dose is adjusted according to the desired urine pH, with monitoring of acid-base, water and electrolyte balance, and without exceeding the maximum infusion rate above. In haemodynamically stable adults and children, urine alkalinisation may be achieved with a bolus of 1-2 mmol sodium bicarbonate per kg body weight, followed by an infusion of 132 mmol sodium bicarbonate in 1 litre of glucose 5% in water, with a flow rate of 1.5-2 times the maintenance fluid rate; urine pH should not exceed 8.5. ADMINISTRATION SAFETY: ensure the solution is infused intravenously — accidental intra-arterial infusion may cause shock or loss of an extremity, and accidental paravenous administration may lead to tissue necrosis. If infused undiluted or too rapidly into peripheral veins, 8.4% w/v may cause vein irritation and consequent phlebitis or thrombosis. Monitoring should include regular checks of acid-base balance, serum electrolytes and water balance; alkalinisation promotes potassium influx into cells and may lead to hypokalaemia, so potassium or calcium deficiencies should be corrected before starting alkalinising therapy. Caution is advised in diabetic ketoacidosis, cardiac arrest and lactic acidosis, where effects on organ function, complication rates and survival have not been investigated sufficiently. No renal dose adjustment is stated in the SPC, but caution is required in all situations where sodium intake must be restricted, including severe kidney insufficiency, cardiac insufficiency, oedema, hypertension and eclampsia. NOTE: a US openFDA record was present in this bundle for 'Elliotts B Solution' (an intrathecal diluent for methotrexate sodium and cytarabine) — that is a different product and indication and was NOT used.

UNIT IS mmol, NOT mg — do not convert or assume milligrams. SPC section 4.2 Paediatric population: 'The dosage has to be adjusted individually. The first dose can be up to 1 mmol/kg body weight, administered by slow intravenous infusion. In newborns and children under 2 years: the daily dose should not exceed 5 mmol per kg body weight per day, administered by slow intravenous infusion.' The 1 mmol/kg figure is an UPPER LIMIT for the first dose ('can be up to'), not a fixed dose. 1 mmol corresponds to 1 ml of the 8.4% w/v solution. In newborns and children under 2 years, 4.2% w/v (or less concentrated) sodium bicarbonate solutions should be preferred, and rapid infusion (10 ml/min) of hypertonic sodium bicarbonate solutions may produce hypernatraemia, a decrease in cerebrospinal fluid pressure and (in preterm infants) possible intracranial haemorrhage. For urine alkalinisation the SPC gives a bolus of 1-2 mmol/kg for haemodynamically stable adults AND children — see adultDose.notes. Verify against a children's formulary before prescribing.