Bicarbonate

# Bicarbonate ## Overview - **Classification**: Electrolyte, alkalizing agent, antacid. - **Mechanism**: Increases plasma bicarbonate, buffers excess hydrogen ions, and raises blood pH. Exerts an antacid effect by neutralizing gastric acid. ## Primary Indications 1. **Metabolic Acidosis** - Correction of severe metabolic acidosis (e.g., DKA, renal failure, lactic acidosis). 2. **Specific Intoxications** - Urinary alkalinization in aspirin or phenobarbital overdose; cardiac stabilization in tricyclic antidepressant (TCA) overdose. 3. **Cardiac Arrest** - Historically used, now controversial. Reserved for prolonged arrest or known pre-existing acidosis. ## Adult Dosing ### Standard Dosing **Severe Metabolic Acidosis** - **Dose**: **0.5-1 mEq/kg** (IV) - **Frequency**: Administer over 1-2 hours initially. Subsequent doses guided by ABG and electrolyte levels. - **Route**: Intravenous infusion. - **Special Considerations**: Dose based on calculated base deficit (e.g., 0.3 x weight (kg) x base deficit). Give half the calculated dose, then reassess. **Tricyclic Antidepressant (TCA) Overdose** - **Dose**: **1-2 mEq/kg** (IV bolus) - **Frequency**: Repeat as needed to maintain QRS duration < 0.10 seconds or pH 7.45-7.55. - **Route**: Intravenous bolus. **Chronic Metabolic Acidosis (Oral)** - **Dose**: **20-30 mEq/day** initially. - **Frequency**: Divided doses (e.g., two to four times daily). - **Route**: Oral. - **Special Considerations**: Adjust based on serum bicarbonate levels. ### Dose Adjustments - **Renal Impairment**: Used to treat acidosis in renal impairment. Adjust dose to achieve target bicarbonate levels. Monitor closely for fluid overload/hypernatremia. - **Hepatic Impairment**: No specific dose adjustment. Monitor electrolytes carefully. - **Elderly Patients**: Start with lower doses and titrate slowly. Increased risk of fluid overload and electrolyte imbalances due to age-related organ decline. ## Pediatric Dosing ### Neonates (0-28 days) - **Indication**: Metabolic Acidosis - **Dose**: **1-2 mEq/kg** (IV) - **Frequency**: Administer slowly over **10-15 minutes**. Repeat as needed based on ABG results. - **Maximum**: Not to exceed **8 mEq/kg/day**. - **Special Notes**: Use **0.5 mEq/mL (4.2%) solution** to reduce osmolality. Rapid administration can cause intracranial hemorrhage. ### Infants (1-12 months) - **Indication**: Metabolic Acidosis - **Dose**: **1-2 mEq/kg** (IV) - **Frequency**: Administer slowly over **10-15 minutes**. Repeat as needed. - **Maximum**: Max **1 mEq/kg/dose every 10 min** (cardiac arrest). - **Special Notes**: Monitor for volume overload and electrolyte shifts. ### Children (1-12 years) - **Indication**: Metabolic Acidosis (including cardiac arrest) - **Dose**: **1-2 mEq/kg** (IV) - **Frequency**: Administer slowly over **10-15 minutes**. For cardiac arrest, **1 mEq/kg** rapidly, may repeat **0.5 mEq/kg** every 10 min. - **Maximum**: No clear single max, but subsequent doses based on ABG to avoid overcorrection. ### Adolescents (13-18 years) - **Indication**: Metabolic Acidosis - **Dose**: Typically follows **adult dosing guidelines** based on weight and clinical need. - **Maximum**: **1 mEq/kg/dose** (acute). ## Safety Information ### Contraindications - **Absolute**: Metabolic alkalosis, hypernatremia, hypocalcemia (risk of tetany), hypochloremia, severe pulmonary edema. - **Relative**: Congestive heart failure, hypertension, renal insufficiency (monitor carefully). ### Common Adverse Effects - **Very Common (>10%)**: Metabolic alkalosis, hypernatremia. - **Common (1-10%)**: Hypokalemia, hypocalcemia (leading to tetany or seizures), fluid overload/edema. - **Serious but Rare**: Extravasation with tissue necrosis, paradoxical CNS acidosis, hyperosmolar syndrome. ### Key Drug Interactions - **Calcium-containing solutions (e.g., Lactated Ringer's)**: Incompatible; forms precipitate. Do not co-administer. - **Acidic drugs (e.g., salicylates, phenobarbital)**: Alkalinizes urine, increasing elimination of acidic drugs. - **Basic drugs (e.g., quinidine, amphetamines, TCAs)**: Alkalinizes urine, decreasing elimination of basic drugs. - **Potassium-depleting diuretics**: Increases risk of hypokalemia. ## Monitoring & Follow-up - **Before Treatment**: Baseline arterial blood gases (ABG), serum electrolytes (Na, K, Cl, Ca), renal function (BUN/Cr). - **During Treatment**: Repeat ABGs and electrolytes frequently (e.g., every 1-2 hours for acute IV administration, daily for oral). Monitor fluid balance. - **Clinical Signs**: Watch for edema, muscle twitching/tetany, mental status changes (signs of alkalosis or paradoxical CNS acidosis). ## Clinical Pearls - 💡 **Administer slowly**: Especially in pediatric patients and those with cardiac or renal issues, to avoid rapid pH shifts and electrolyte disturbances. - 💡 **Compatibility**: **Do NOT mix bicarbonate with calcium-containing IV solutions** due to risk of precipitation. Use separate IV lines. - 💡 **Cardiac Arrest**: Its routine use in cardiac arrest is largely **discontinued** unless specific indications (e.g., severe pre-existing acidosis) are met. - 💡 **Oral Formulations**: Useful for chronic metabolic acidosis, but monitor for GI upset and hypernatremia. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.