What medications are used for analgesia, sedation, and muscle relaxation in neonatal intubation?

Medications for Neonatal Intubation

Recommended Premedication Regimen

For non-emergent neonatal intubation, use a combination of atropine (20 mcg/kg), fentanyl (2-5 mcg/kg), and a neuromuscular blocking agent such as rocuronium (0.6 mg/kg) or mivacurium (200 mcg/kg). 1, 2, 3

This approach addresses the three critical components: vagolytic protection, analgesia, and muscle relaxation to optimize intubation conditions while minimizing physiologic disturbances.

Component Medications and Dosing

Vagolytic Agent (Anticholinergic)

• Atropine 20 mcg/kg IV should be administered first to prevent bradycardia during laryngoscopy 1, 2, 3, 4
• This prevents the vagal response that commonly occurs with airway manipulation in neonates 1

Analgesic Agent (Opioid)

Fentanyl is preferred over morphine for neonatal intubation due to its rapid onset of action 1

• Fentanyl 2-5 mcg/kg IV provides effective analgesia with onset within minutes 1, 2, 3, 5
• Morphine has a delayed onset and does not adequately reduce hypoxia with bradycardia during intubation 1
• Higher fentanyl doses (1-5 mcg/kg) are recommended specifically for intubation procedures 1
• Caution: Rapid administration of fentanyl can cause chest wall and glottic rigidity, even at doses as low as 1 mcg/kg, so it should be administered over several minutes unless a muscle relaxant is also being given 1

Neuromuscular Blocking Agent

Rocuronium 0.6 mg/kg IV is the preferred muscle relaxant for neonatal intubation 6, 7

• Rocuronium provides excellent intubation conditions with onset in 60-75 seconds 7
• It is safer than succinylcholine in neonates, particularly those with burns, neuromuscular disease, prolonged critical illness, or spinal cord injury where succinylcholine can cause life-threatening hyperkalemia 6
• Duration of action is 30-60 minutes, which is acceptable given the safety benefit 6

Alternative: Mivacurium 200 mcg/kg IV can be used if rocuronium is unavailable 3

• Provides muscle relaxation at a mean of 94 seconds with return of spontaneous movements at approximately 15-30 minutes 3
• Demonstrated excellent intubation conditions with high success rates even for inexperienced personnel 3

Succinylcholine 2 mg/kg IV was historically used but carries significant risks 4, 5

• Contraindicated in neonates with burns (after 24-48 hours post-injury), neuromuscular disease, prolonged immobilization, or critical illness due to risk of fatal hyperkalemia 6
• If cardiac arrest occurs immediately after succinylcholine, suspect hyperkalemia and treat aggressively 6

Sedative Considerations

Midazolam should NOT be routinely used for neonatal intubation 1, 8

• Meta-analyses show midazolam provides no apparent clinical benefit in ventilated neonates and may cause significant adverse effects including prolonged hypotension 1, 8
• Benzodiazepines in neonates are associated with unfavorable patient outcomes 1
• If used, the dose is 0.1 mg/kg IV, but this should be reserved for specific circumstances 2

Etomidate 0.2-0.4 mg/kg IV can be considered as an alternative sedative 1

• Does not lower blood pressure and may lower ICP, making it desirable for patients with head injury or hypotension 1
• Rapid onset with duration of 10-15 minutes 1
• Does not have analgesic properties, so must be combined with fentanyl 1

Clinical Algorithm for Non-Emergent Intubation

1. Prepare equipment and personnel with airway management skills present 9
2. Administer atropine 20 mcg/kg IV first 2, 3, 4
3. Administer fentanyl 2-5 mcg/kg IV slowly over 1-2 minutes (unless giving muscle relaxant immediately after) 1, 2, 5
4. Administer rocuronium 0.6 mg/kg IV 6, 7
5. Wait 60-90 seconds for muscle relaxation to occur 7, 3
6. Perform laryngoscopy and intubation - expect successful intubation within 60-247 seconds 2, 5
7. Monitor continuously: oxygen saturation, heart rate, blood pressure throughout procedure 2

Important Caveats and Pitfalls

Avoid These Common Errors:

• Do not use morphine for intubation - its delayed onset makes it ineffective for preventing hypoxia and bradycardia during the procedure 1
• Do not use midazolam as primary sedation in neonates due to lack of benefit and potential harm 1, 8
• Do not use succinylcholine in high-risk neonates (burns, neuromuscular disease, prolonged critical illness) 6
• Do not give fentanyl too rapidly without a muscle relaxant, as this can cause chest wall rigidity 1, 5

Special Populations:

• Preterm neonates: Use the same dosing regimen; they may have slightly prolonged duration of neuromuscular blockade 7
• Neonates already receiving morphine infusion: Omit additional fentanyl or reduce dose 2
• Hemodynamically unstable neonates: Consider etomidate instead of midazolam for sedation to avoid hypotension 1

Monitoring Requirements:

• Continuous cardiorespiratory monitoring is mandatory 2
• Have reversal agents available: naloxone for opioid reversal, sugammadex for rocuronium reversal 1
• Be prepared to provide bag-mask ventilation during muscle relaxation 3
• Neuromuscular monitoring should be employed when muscle relaxants are used 6, 9

Success Metrics:

• With this regimen, expect successful intubation on first attempt in 67-76% of cases 2, 3
• Median time to successful intubation: 60-247 seconds 2, 5
• Physiologic stability: heart rate should decrease slightly, oxygen saturation should increase or remain stable 2