What intermittent intravenous push sedatives and dosing are recommended for an adult mechanically ventilated patient who needs brief procedural sedation or agitation control when a continuous infusion is not feasible?

Intermittent IV Push Sedation for Mechanically Ventilated Patients

For mechanically ventilated adults requiring brief procedural sedation or agitation control when continuous infusion is not feasible, use intermittent IV boluses of midazolam 2 mg every 15 minutes as needed, or propofol 10-20 mg boluses for rapid effect, always after ensuring adequate analgesia with fentanyl 25-100 mcg boluses. 1, 2, 3

Analgesia-First Approach (Always Start Here)

Before administering any sedative, treat pain first with IV opioids, as pain and discomfort are the primary drivers of agitation in mechanically ventilated patients. 4, 5, 1

Opioid Bolus Dosing:

• Fentanyl: 25-100 mcg IV bolus (preferred for rapid onset) 1
• Morphine: 2-5 mg IV bolus (alternative option) 1
• Repeat every 5-15 minutes as needed to control pain before escalating sedation 4, 1

If a patient is already on a continuous opioid infusion:

• Give bolus dose of 2× the hourly infusion rate for morphine/hydromorphone every 15 minutes as needed 4
• Give bolus dose equal to the hourly infusion rate for fentanyl every 5 minutes as needed 4

Intermittent Sedative Bolus Dosing

Midazolam (Second-Line After Analgesia)

For opioid-naïve patients needing sedation:

• Initial bolus: 2 mg IV over 2 minutes 4, 1, 2
• Wait 2 minutes to evaluate sedative effect 2
• Additional titration: 1 mg IV over 2 minutes, waiting 2+ minutes between doses 2
• Total doses >3.5 mg usually not necessary in elderly/debilitated patients 2

For patients already on midazolam infusion:

• Give bolus of 1-2× the hourly infusion rate every 5 minutes as needed for breakthrough agitation 4
• If patient requires 2 bolus doses within 1 hour, consider doubling the infusion rate 4

Propofol (Alternative for Rapid Effect)

For rapid sedation when hypotension is not a concern:

• Bolus: 10-20 mg IV for quick increase in sedation depth 3
• Onset in 1-2 minutes 1
• Avoid in patients with compromised myocardial function, intravascular volume depletion, or sepsis due to hypotension risk 3

Critical Caveats and Pitfalls

Benzodiazepines should be avoided as routine sedation because they prolong mechanical ventilation, increase ICU length of stay, and significantly increase delirium incidence compared to propofol or dexmedetomidine. 4, 5, 1, 6 However, for intermittent bolus use when continuous infusion is not feasible, midazolam remains a practical option given its rapid onset and established dosing protocols. 2

Never use sedatives to treat agitation without first addressing:

• Pain (use opioids first) 4, 1
• Hypoxemia, hypoglycemia, hypotension 1
• Alcohol or drug withdrawal 4
• Delirium (requires different management) 4

In elderly patients (>55 years) or those with severe systemic disease:

• Reduce midazolam doses by at least 50% 2
• Start with 1 mg boluses instead of 2 mg 2
• Allow longer intervals between doses 2

If concomitant CNS depressants or opioids are used:

• Reduce midazolam dose by at least 50% 2
• Expect slower recovery profile 3

Monitoring Requirements

• Use Richmond Agitation-Sedation Scale (RASS) to assess sedation level before and after each bolus 4, 5, 1
• Target RASS -2 to 0 (light sedation) for most patients 5, 1, 6
• Reassess sedation level every 6 hours minimum 1
• Screen for delirium daily using CAM-ICU 4, 1

When Continuous Infusion Becomes Necessary

If patient requires ≥2 bolus doses within 1 hour, transition to continuous infusion rather than repeated boluses:

• Midazolam: Start at 1 mg/hr after 2 mg loading bolus 4
• Propofol: Start at 5 mcg/kg/min (0.3 mg/kg/hr) 3

The Surviving Sepsis Campaign recommends that continuous or intermittent sedation be minimized in mechanically ventilated sepsis patients, targeting specific titration endpoints. 4 This applies equally to intermittent bolus strategies—use the minimum effective dose and frequency.