8,4% sodium bicarbonate for infusion 20 ml vial by B.Braun
Warning: Electrolyte balance and kidney function must be controlled carefully when using bicarbonate infusion
- Correction of metabolic acidosis
- Urine alkalization in the case of intoxication with weak organic acids, e. g. barbiturates or acetylsalicylic acid
- Urine alkalization in order to improve the solubility of drug substances which are poorly soluble in neutral or acid medium, e. g. methotrexate, sulphonamides
- Urine alkalization in the case of haemolysis
hypernatraemia (high natrium levels)
hypokalaemia (low potassium levels)
Sodium Bicarbonate Inj. is contraindicated in patients who are losing chloride by vomiting or from continuous gastrointestinal suction, and in patients receiving diuretics known to produce a hypochloremic alkalosis.
Online sodium bicarbonate deficit calculator
Calculation of sodium bicarbonate requirement in metabolic acidosis (pubmed)
Some common calculation formulas:
Bicarbonate deficit = 0.2 x weight (kg) x base deficit (mEq/L). (Ghosh A, Habermann TM. Mayo Clinic Internal Medicine Concise Textbook. CRC Press, 2007. p.599:914.)
Kurtz I. Acid-Base Case Studies. 2nd Ed. Trafford Publishing (2004); 68:150. recommendation:
“Following the acute administration of bicarbonate as a bolus, its effect on the systemic pH will be maximal. Over the subsequent hours, the bicarbonate which was originally administered will be taken up into cells. In addition, the elevation of systemic pH decreases the compensatory ventilatory response. These two effects will decrease the systemic pH from the maximum value that was obtained immediately following the administration of bicarbonate.” Effective volume of distribution of bicarbonate varies with the HCO3- concentration:
|Bicarb Vd = (0.4 + 2.6/HCO3-) x Lean body weight.Bicarbonate deficit = Bicarb Vd x (desired [HCO3-] – measured [HCO3-])Lean body weight defined as usual IBW equations:
Estimated ideal body weight in (kg):
Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet.
Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet.
1] Greater degree of metabolic acidosis –> Greater increases in bicarb Vd —> Larger amounts of bicarb must be administered.
2] Following admin of bicarb (as a bolus), there is a time-dependent decrease in blood HCO3- conc. A portion of the HCO3- which is initially distributed in the ECF space, subsequently enters the intracellular space.
3] As the blood HCO3- conc increases, the PCO2 increases as a results of a decrease in alveolar ventilation.
Koda-Kimble et al:
Replace 50% over 3 to 4 hours and the reminder over 24 hours. Once the pH is 7.2 – 7.25, the serum [HCO3-] should not be increased by more than 4 to 8 Eq/L over 6 to 12 hours to avoid the risks of over-alkalinization (paradoxical CNS acidosis; decreased affinity of hemoglobin for oxygen leading to tissue hypoxia and lactic acid production; sodium overload; and hypokalemia).
Kollef MH, Bedient TJ, Isakow W, Witt CA. The Washington Manual of Critical Care. Lippincott Williams & Wilkins, 2007; p185:583.
“Primary goal in treating metabolic acidosis is reversal of the underlying process. Administration of bicarbonate in controversial, as some clinical parameters may actually worsen… ” “However, partial correction should be considered in the setting of life-threatening metabolic acidosis(pH<7.1) or when the serum bicarbonate is low enough (i.e., <10 to 12 mEq/L) that loss of effective respiratory compensation would result in life-threatening acidosis.”
Bicarbonate deficit: The amount of bicarbonate req’d to correct a metabolic acidosis can be estimated from the following formula:
Volume of distribution (Vd) = Total body weight (kg) x [0.4 + (2.4/[HCO3-])
(Deficit) mEq of NaHCO3 = Vd x target change in [HCO3-]