Dexmedetomidine (Precedex) Titration Protocol
Start dexmedetomidine at 0.2-0.7 mcg/kg/hour as a maintenance infusion without a loading dose in most ICU patients, or use a 1 mcg/kg loading dose over 10 minutes followed by the same maintenance rate in hemodynamically stable patients requiring rapid sedation. 1
Standard Dosing Algorithm
Loading Dose Decision Tree
Hemodynamically stable patients requiring rapid sedation:
- Administer 1 mcg/kg IV over 10 minutes 1
- Monitor blood pressure and heart rate every 2-3 minutes during infusion 1
- Have atropine immediately available for bradycardia 2
Avoid loading dose entirely in:
- Hemodynamically unstable patients 1
- Elderly patients 1
- Severe cardiac disease 1
- Hyponatremic patients with confusion 2
- Patients with hepatic dysfunction 1, 2
Maintenance Infusion Titration
Initial rate: 0.2-0.7 mcg/kg/hour 1
- Start at 0.2 mcg/kg/hour in high-risk patients (elderly, hepatic dysfunction, hemodynamic instability) 1, 2
- Start at 0.5-0.7 mcg/kg/hour in stable patients requiring moderate sedation 1
Titration increments:
- Increase by 0.1-0.2 mcg/kg/hour every 15-30 minutes based on sedation target 1
- Maximum rate: 1.5 mcg/kg/hour as tolerated 1
- Titrate to desired RASS score using validated sedation scales 1
Preparation and Administration
Standard concentration: 4 mcg/mL 1
- For 100 mcg ampoule: add to 25 mL of 0.9% normal saline 1
- For 200 mcg ampoule: add to 50 mL of 0.9% normal saline 1
Example for 70 kg patient:
- Loading dose (if used): 70 mcg = 17.5 mL over 10 minutes 1
- Maintenance at 0.5 mcg/kg/hour: 35 mcg/hour = 8.75 mL/hour 1
Context-Specific Modifications
Airway Procedures (Awake Intubation)
- Bolus: 0.5-1 mcg/kg over 5 minutes 1
- Maintenance: 0.3-0.6 mcg/kg/hour 1
- Faster bolus (5 minutes minimum) acceptable when immediate sedation needed 1
Non-Intubated ICU Patients
- Omit loading dose 1
- Start at 0.2 mcg/kg/hour 1
- Particularly useful for agitated delirium 2
- Monitor continuously for airway obstruction from loss of oropharyngeal muscle tone 1
Hepatic Dysfunction
- Start at lower end of maintenance range: 0.2 mcg/kg/hour 1, 2
- Elimination half-life prolonged from 1.8-3.1 hours to significantly longer 1, 3
- Avoid loading dose 2
Pediatric Patients
Critical Monitoring Requirements
During loading dose (if used):
- Blood pressure and heart rate every 2-3 minutes 1, 2
- Watch for biphasic response: transient hypertension followed by hypotension within 5-10 minutes 1
During maintenance infusion:
- Continuous hemodynamic monitoring essential 1, 2
- Hypotension occurs in 10-20% of patients 1, 3
- Bradycardia occurs in 10-18% of patients, typically within 5-15 minutes 1
- More serious arrhythmias include first-degree and second-degree AV block, sinus arrest 1
Respiratory monitoring in non-intubated patients:
- Continuous pulse oximetry 1
- Watch for hypoventilation and hypoxemia 1
- Despite minimal respiratory depression, airway obstruction can occur 1
Common Pitfalls to Avoid
Never administer faster than 5 minutes for any bolus dose 1
Do not use standard loading dose in:
- Patients already hypotensive or bradycardic 1
- Active hyponatremia with confusion (address electrolyte abnormality first) 2
- Severe hepatic impairment 1, 2
Avoid as monotherapy when:
- Deep sedation required (propofol more effective) 1
- Neuromuscular blockade used (combine with GABA agonist for amnesia) 1
- Severe ventilator dyssynchrony present 1
Advantages Supporting Use
Unique sedation profile:
- Patients remain easily arousable and cooperative 1, 4
- Minimal respiratory depression unlike benzodiazepines or opioids 1, 3
- Can continue infusion safely after extubation 1
Delirium reduction:
- Reduced delirium from 23% to 9% compared to benzodiazepines 1
- Particularly effective for hyperactive delirium 2
- Preserves sleep architecture with dose-dependent stage N3 non-REM sleep 1
Opioid-sparing effects:
- Reduces narcotic requirements by 30-60% 3
- Analgesic effects last up to 24 hours despite 1.8-3.1 hour half-life 3
Clinical outcomes: