In a child without severe respiratory disease, severe hepatic impairment, paradoxical benzodiazepine reactions, or midazolam allergy, what oral sedative syrup and dose should be used to induce sleep for a CT scan?

Oral Chloral Hydrate or Oral Pentobarbital for Pediatric CT Sedation

For a child requiring sedation for CT imaging, oral chloral hydrate at 50-75 mg/kg (maximum 1000 mg) is the preferred first-line oral sedative syrup, particularly for infants and children under 18 months of age. 1

Primary Recommendation: Chloral Hydrate

Chloral hydrate syrup should be administered at an initial dose of 50-75 mg/kg, with the option to give additional doses of 25-50 mg/kg up to a maximum total dose of 100 mg/kg if needed. 1 This agent demonstrates:

• Excellent absorption and fast induction time with minimal respiratory effects 2
• Success rates comparable to pentobarbital with similar sedation duration (81 ± 34 minutes) and time to discharge (100-103 minutes) 1
• Low adverse event rate of 1.7%, primarily consisting of mild oxygen desaturation responsive to airway repositioning 1
• Optimal efficacy in children under 18 months of age, making it the preferred choice for younger infants 1

Alternative Option: Oral Pentobarbital

If chloral hydrate is unavailable or ineffective, oral pentobarbital at 4 mg/kg represents an effective alternative with comparable efficacy and safety profile. 1

Key characteristics include:

• Similar time to sedation (196 ± 14 minutes) and discharge time (100 ± 35 minutes) as chloral hydrate 1
• Adverse event rate of 1.6%, including rare paradoxical reactions, transient desaturation, and prolonged sedation at higher doses 1
• Best results in children younger than 8 years, with decreased efficacy in older children or those weighing >50 kg 1

Critical Safety Considerations

Monitoring Requirements

• Continuous pulse oximetry is mandatory throughout the sedation period 1
• Fasting status should be confirmed prior to sedation, as all guideline studies were conducted in fasted patients 1
• Observe for at least 1 hour post-procedure before discharge 3

Common Pitfalls to Avoid

• Do not use oral midazolam as a sole agent for CT sedation - it demonstrates only 19% success rate compared to 97% with pentobarbital for CT imaging 1
• Avoid combining pentobarbital with midazolam - this combination increases time to sedation (8.0 vs 6.5 minutes) and prolongs discharge time by 14 minutes without improving efficacy (99.8% vs 99.5%) 1
• Be aware of paradoxical hyperactivity, which occurs more frequently with pentobarbital, particularly in children over 8 years (8.4% incidence) 1

Management of Complications

• Transient desaturation (most common adverse event): Responds to simple airway repositioning or supplemental oxygen in >95% of cases 1
• Prolonged sedation: More likely with pentobarbital doses >5 mg/kg; 19% of children may sleep >8 hours with multiple doses 1
• Paradoxical agitation: Occurs in <1% with chloral hydrate vs up to 8.4% with pentobarbital; typically self-limited 1

Practical Administration Algorithm

1. Confirm fasting status and absence of contraindications (severe respiratory disease, hepatic impairment)
2. For children <18 months: Start with chloral hydrate 50-75 mg/kg orally 1
3. For children 18 months to 8 years: Either chloral hydrate 50-75 mg/kg or pentobarbital 4 mg/kg orally 1
4. Wait 15-20 minutes for onset of sedation 1
5. If inadequate sedation: Give supplemental dose (chloral hydrate 25-50 mg/kg up to 100 mg/kg total, or consider alternative agent) 1
6. Monitor continuously with pulse oximetry throughout procedure and recovery 1

Why Not Other Oral Agents?

• Oral midazolam: Demonstrates unacceptably low success rate (19%) for CT imaging despite being effective for anxiolysis 1
• Rectal midazolam: Shows minimal sedative effect for imaging procedures 4
• Oral diazepam: Reserved only for anxious older children (>5 years) in MRI settings, not recommended for CT 1