Sodium Bicarbonate

TCA / sodium-channel blocker overdose - 1–2 mEq/kg IV bolus narrows QRS by overcoming sodium-channel blockade; titrate to QRS less than 100 ms and arterial pH 7.45–7.55 with infusion as needed.

Local anesthetic systemic toxicity (LAST) - Adjunct after lipid emulsion in severe LAST with QRS prolongation; same dosing principle as TCA overdose.

Severe metabolic acidosis - Reserve for arterial pH below 7.10 with hemodynamic compromise; routine bicarbonate in diabetic ketoacidosis (DKA) and lactic acidosis is no longer recommended.

Hyperkalemia - Slow intracellular potassium shift; useful only when concurrent acidosis is present, otherwise calcium and insulin/dextrose are first line.

Cardiac arrest - Not routinely indicated by ACLS; consider in tricyclic overdose, hyperkalemia, or prolonged arrest with documented severe acidosis.

Local infiltration buffering - Adding 1 mEq per 9–10 mL of lidocaine reduces injection pain; do not buffer bupivacaine because it precipitates.

Line incompatibility - Precipitates with calcium (forms calcium carbonate), inactivates catecholamines (epinephrine, norepinephrine, dopamine, dobutamine), and is incompatible with vecuronium, rocuronium, midazolam, and propofol; flush thoroughly between drugs.

Management of excessive effect - Stop infusion, increase ventilation to clear CO2, replace ionized calcium and potassium, consider acetazolamide for prolonged metabolic alkalosis.

Drug Interactions - Alkalinization of urine alters renal clearance: enhances elimination of weak acids (salicylates, phenobarbital) and slows elimination of weak bases (amphetamines, quinidine).

Pediatric Implications - Neonates and small infants must receive bicarbonate diluted to 0.5 mEq/mL (1:1 with sterile water) and given slowly to avoid intracranial hemorrhage from osmotic shifts; dose 1–2 mEq/kg IV.

Obstetric Implications - Crosses placenta minimally; safe in pregnancy when maternal indication exists; correcting maternal acidosis improves fetal pH and oxygen delivery.

Absolute: severe metabolic or respiratory alkalosis, severe symptomatic hypocalcemia (will worsen tetany), uncorrected hypokalemia, severe hypernatremia.

Relative: heart failure or pulmonary edema (sodium and volume load), oliguric renal failure, neonates given undiluted hypertonic solution.

Caution: simultaneous administration of calcium-containing fluids or catecholamines through the same line; pulmonary disease with limited ability to clear CO2.

TCA or other sodium-channel blocker overdose: 1–2 mEq/kg IV bolus, repeat to QRS less than 100 ms.

Local anesthetic systemic toxicity adjunct: 1–2 mEq/kg IV.

Severe metabolic acidosis (pH less than 7.10 with shock): 1 mEq/kg IV bolus, recheck arterial blood gas (ABG).

Hyperkalemia with concurrent acidosis: 1 mEq/kg IV over 5 min.

150 mEq in 1 L D5W (isotonic) at 150–250 mL/hr for urinary alkalinization or ongoing acidosis; titrate to urine pH 7.5–8.5 or arterial pH.

Provides bicarbonate (HCO3-) which combines with hydrogen ion to form carbonic acid, then dissociates to CO2 and water; raises pH and serum sodium and produces an intracellular potassium shift as alkalosis develops.

Not metabolized; converted to CO2 and water.

Pulmonary (as CO2) and renal.

8.4% solution = 1 mEq/mL; standard 50 mL adult amp delivers 50 mEq and ~1.15 g of sodium.

Hyperosmolar (~2000 mOsm/L for 8.4%); central line preferred for repeated bolus or prolonged infusion. Vesicant on extravasation.

For neonates and infants, dilute 1:1 with sterile water to 0.5 mEq/mL.

Incompatible with calcium, catecholamines, midazolam, propofol, and many neuromuscular blockers; flush line thoroughly between drugs.