Intranasal Midazolam Dosing: Number of Puffs Required
For intranasal midazolam spray at 2.5 mg per puff, administer the number of puffs that delivers 0.2 mg/kg of the patient's body weight, with a maximum total dose of 10 mg (4 puffs maximum). 1
Calculating the Number of Puffs
To determine the exact number of puffs needed:
- Calculate the target dose: Multiply the patient's weight in kg by 0.2 mg/kg 2, 3
- Divide by 2.5 mg per puff to determine the number of puffs required 1
- Round to the nearest practical puff increment (0.5 or whole puffs depending on device capability)
- Never exceed 4 puffs total (10 mg maximum dose) 1
Practical Examples by Weight
- 10 kg child: 0.2 mg/kg × 10 kg = 2 mg total dose ÷ 2.5 mg/puff = 0.8 puffs (round to 1 puff) 2
- 20 kg child: 0.2 mg/kg × 20 kg = 4 mg total dose ÷ 2.5 mg/puff = 1.6 puffs (round to 1.5-2 puffs) 2
- 30 kg child: 0.2 mg/kg × 30 kg = 6 mg total dose ÷ 2.5 mg/puff = 2.4 puffs (round to 2-2.5 puffs) 2
- 40 kg child: 0.2 mg/kg × 40 kg = 8 mg total dose ÷ 2.5 mg/puff = 3.2 puffs (round to 3 puffs) 2
- 50 kg or greater: 0.2 mg/kg would exceed 10 mg, so cap at 4 puffs (10 mg maximum) 1
Critical Dosing Context
The 0.2 mg/kg dose represents the lower end of the effective intranasal midazolam range and may provide inadequate sedation for some procedures. 2, 3
- Recent high-quality evidence from a 2025 randomized trial demonstrated that 0.4-0.5 mg/kg intranasal midazolam are the optimal doses for procedural sedation in children undergoing laceration repair, with the 0.2 mg/kg dose being eliminated early in the adaptive trial for inadequate sedation 3
- A 2012 study comparing 0.2 mg/kg versus 0.3 mg/kg found that at 20 minutes post-administration, only 63% of children receiving 0.2 mg/kg achieved adequate sedation compared to 76% receiving 0.3 mg/kg 2
- If using 0.2 mg/kg, expect that 37-40% of patients may require supplemental sedation or have suboptimal procedural conditions 2, 3
Administration Technique
- Divide the total dose between both nostrils when possible to improve absorption and tolerability 4
- Use a volume of administration of 0.5 mL per nostril when feasible, as this provides optimal balance between rapid onset (4.3 minutes to minimal sedation) and clinician satisfaction with ease of administration 4
- Avoid volumes less than 0.2 mL per nostril due to reduced clinician satisfaction with administration technique 4
Safety Monitoring Requirements
- Continuous pulse oximetry is mandatory throughout the procedure and recovery period 5
- Have flumazenil immediately available to reverse life-threatening respiratory depression 5
- Monitor for respiratory depression, which can occur up to 30 minutes after administration 6
- Paradoxical agitation occurs in approximately 6% of younger children receiving intranasal midazolam 6
Common Pitfall to Avoid
The most critical error is using 0.2 mg/kg when higher doses (0.4-0.5 mg/kg) are now supported by the strongest evidence for procedural sedation. 3 If institutional protocols mandate 0.2 mg/kg, be prepared with a rescue sedation plan for the 37-40% of patients who will have inadequate sedation at this dose 2, 3