What volume of normal saline should be flushed before and after an intravenous push medication?

Normal Saline Flush Volume for IV Push Medications

For most IV push medications in adults, flush with 5-10 mL of normal saline both before and after administration; for pediatric patients, use 5-10 mL after medication administration, with larger volumes (up to 20 mL) recommended for older children when administering time-sensitive medications like adenosine. 1

Standard Adult Practice

• Flush with 5 mL of normal saline after IV push medication administration to ensure complete drug delivery from the catheter dead space into the patient's circulation 1
• The 5 mL flush volume is specifically recommended in American Heart Association guidelines for endotracheal medication administration (followed by ventilations), establishing this as a standard reference volume 1
• Pre-medication flushing is not explicitly mandated in guidelines but is standard practice to confirm catheter patency before drug administration

Pediatric Considerations

• For pediatric patients receiving adenosine, flush immediately with 5-10 mL of normal saline using a 2-syringe technique 1
• Larger flush volumes up to 20 mL may be helpful in older children to ensure rapid drug delivery to the heart, which is critical for adenosine efficacy 1
• The most proximal IV site possible should be used for time-sensitive medications to minimize transit time 1

Critical Medication-Specific Exceptions

Adenosine (Time-Critical)

• Requires immediate rapid flush after administration because the drug has an extremely short half-life and must reach the heart quickly 1
• Use 5-10 mL in younger children, up to 20 mL in older children 1

Endotracheal Medications

• When medications are given via endotracheal tube, flush with at least 5 mL of normal saline followed by 5 consecutive positive-pressure ventilations 1
• This applies to LEAN medications (lidocaine, epinephrine, atropine, naloxone) 1

Clinical Rationale

• Residual drug volume in IV administration sets averages 13.1-16.7 mL, meaning substantial medication can remain in the tubing without adequate flushing 2
• Studies demonstrate that up to 21% of antibiotic doses can be discarded when administration sets are not flushed 2
• Non-flushing occurs in 74% of clinical administrations outside oncology settings, representing a significant under-dosing risk 2

Common Pitfalls to Avoid

• Never assume the medication has been fully delivered without flushing - the dead space in standard IV tubing requires active flushing to clear 2
• Do not use inadequate flush volumes - volumes less than 5 mL may not adequately clear the catheter and tubing dead space 1
• For rapid-acting medications like adenosine, delayed or slow flushing renders the drug ineffective because it will be metabolized before reaching the target site 1
• Avoid using water for any IV flush - only normal saline (0.9% sodium chloride) should be used 3

Practical Implementation

• Use a 2-syringe technique for time-sensitive medications: one syringe with the drug, one with the flush, allowing immediate sequential administration 1
• Administer the flush at the same rate as the medication unless otherwise specified (e.g., rapid push for adenosine) 1
• For gravity-driven infusions, recognize that flow rates can vary 2.9-fold depending on catheter size and height, making mechanical pumps preferable for precision 4