Sodium Bicarbonate Infusion Duration for Metabolic Acidosis
Sodium bicarbonate should be infused over 4 to 8 hours for non-emergent metabolic acidosis, with an initial dose of 2 to 5 mEq/kg body weight, though cardiac arrest requires rapid administration over 5-10 minutes per bolus. 1
Emergency vs Non-Emergency Administration Rates
Cardiac Arrest (Rapid Administration)
- Administer one to two 50 mL vials (44.6 to 100 mEq) as a rapid intravenous bolus initially 1
- Continue at a rate of 50 mL (44.6 to 50 mEq) every 5 to 10 minutes if necessary, guided by arterial pH and blood gas monitoring 1
- In cardiac arrest scenarios, the risks from acidosis exceed those of hypernatremia, justifying rapid infusion despite the hypertonic nature of bicarbonate solutions 1
Non-Emergent Metabolic Acidosis (Standard Infusion)
- The FDA-approved dosing specifies 2 to 5 mEq/kg body weight infused over a 4 to 8 hour period for older children and adults with less urgent forms of metabolic acidosis 1
- Each individual infusion should be administered over 30 minutes, with volumes ranging from 125-250 mL per infusion 2
- Maximum total volume should not exceed 1000 mL within 24 hours after initiation 2
Specific Clinical Scenarios
Severe Metabolic Acidosis (pH <7.0)
- For diabetic ketoacidosis with pH 6.9-7.0: infuse 50 mmol sodium bicarbonate in 200 mL sterile water at 200 mL/hour (1-hour duration) 3
- For diabetic ketoacidosis with pH <6.9: infuse 100 mmol sodium bicarbonate in 400 mL sterile water at 200 mL/hour (2-hour duration) 3
- Continue infusion until pH rises above 7.0, then reassess the need for further therapy 4
Sodium Channel Blocker Toxicity
- Initial bolus of 50-150 mEq given as rapid push 3
- Follow with continuous infusion of 150 mEq/L solution at 1-3 mL/kg/hour to maintain alkalosis 3, 5
- Continue until resolution of QRS prolongation and hemodynamic stability 3
Chronic Kidney Disease with Metabolic Acidosis
- Continue sodium bicarbonate drip until serum bicarbonate reaches ≥22 mmol/L 4
- Monitor serum bicarbonate every 2-4 hours during active infusion therapy 5, 4
Critical Monitoring During Infusion
Frequency of Assessment
- Measure arterial blood gases every 2-4 hours to assess pH, PaCO2, and bicarbonate response 3
- Monitor serum electrolytes (sodium, potassium, ionized calcium) every 2-4 hours 3
- Check for metabolic alkalosis (pH >7.45) which indicates overcorrection 4
Target Parameters
- Target pH of 7.2-7.3, not complete normalization 3, 1
- Avoid serum sodium >150-155 mEq/L 3
- Avoid pH >7.50-7.55 3
- Achieving total CO2 content of about 20 mEq/L at the end of the first day is usually associated with normal blood pH 1
Important Caveats
Stepwise Therapy Approach
- Bicarbonate therapy should always be planned in a stepwise fashion since the degree of response from a given dose is not precisely predictable 1
- It is unwise to attempt full correction of low total CO2 content during the first 24 hours of therapy, as this may be accompanied by unrecognized alkalosis due to delayed readjustment of ventilation 1
- Values for total CO2 brought to normal or above normal within the first day are very likely to be associated with grossly alkaline blood pH values with ensuing undesired side effects 1
Administration Safety
- Ensure adequate ventilation is established before administering bicarbonate, as it produces CO2 that must be eliminated 3
- Never mix sodium bicarbonate with calcium-containing solutions or vasoactive amines 3, 5
- Flush IV line with normal saline before and after bicarbonate administration 3