Dexmedetomidine (Precedex) - ICU Advantage Lecture

Jul 24, 2024

Dexmedetomidine (Precedex) - ICU Advantage Lecture

Introduction

  • Presenter: Eddie Watson
  • Goal: Simplify complex Critical Care subjects for ICU success
  • Invitation to subscribe for more content and updates
  • ICU Advantage Academy launching March 15th
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    • CE credits available (30+ contact hours)
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Dexmedetomidine Overview

  • Drug Name: Dexmedetomidine (Trade Name: Precedex)
  • FDA Approval: 1999
  • Uses: Short-term sedative and analgesic for <24 hours
  • Primary Use: Mechanically ventilated patients in ICU
  • Side Effects: Initial concern about withdrawal (rebound hypertension), but not consistently observed
  • Mechanism: Selective Alpha-2 Adrenergic Agonist (like clonidine)
    • Central nervous system action -> sedation and analgesia
    • Prevents norepinephrine release -> sedation
    • Acts on brain stem -> increases GABA inhibition
    • Sedation resembles natural sleep -> less amnesia
    • No respiratory depression -> major benefit
  • Comparison: Not as powerful as other sedatives (propofol, benzodiazepines)

Actions and Effects

  • Therapeutic Actions: Alpha-2 adrenergic receptor (CNS & periphery)
    • Inhibits norepinephrine release
    • Results in clinical changes: bradycardia, hypotension
  • Indications:
    1. Short-term sedation for intubated ICU patients
    2. Sedation for non-intubated patients (surgery/procedures)
    3. NEW: Acute agitation (schizophrenia, bipolar disorder)
  • Off-label Uses:
    • Awake procedures (craniotomies, intubations)
    • Post-anesthetic shivering
    • Sedation enhancement during general anesthesia
    • Maintain sedation through extubation
    • Peripheral nerve blocks
    • Alcohol withdrawal
    • Cardiovascular effects (amphetamine, cocaine overdose)

Contraindications & Cautions

  • Contraindications: Hypersensitivity
  • Cautions:
    • High vagal tone (bradycardia risk)
    • Older adults, hepatic impairment, heart blocks, ventricular dysfunction
    • Hypovolemia, hypotension, diabetes, chronic hypertension

Adverse Effects

  • Central Nervous System: Fever, agitation, anxiety, chills, rigors
  • Cardiovascular: Hypotension, hypertension, bradycardia, AFib, tachycardia
  • ENT: Dry mouth
  • GI: Nausea, vomiting, increased thirst, constipation
  • GU: Oliguria, acute renal failure
  • Hematologic: Anemia, bleeding
  • Metabolic: Dysregulations in glucose, calcium, phosphorus
  • Respiratory: Atelectasis, pleural effusion, hypoxia, pulmonary edema

Dosage and Administration

  • Concentration: 4 mcg/mL (max concentration)
  • Common Mixes: 400 mcg/100 mL, 200 mcg/50 mL, 80 mcg/20 mL, 1000 mcg/250 mL (high rate use)
  • Initial Dosing: 1 mcg/kg over 10 min (Loading dose)
  • Maintenance: 0.2-1.4 mcg/kg/hr (titrate to RASS)
  • Pharmacokinetics: Rapid onset, liver metabolism, urine excretion, no antidote

Nursing Considerations

  • Training Requirements: Procedural sedation training
  • Monitoring: BP, HR, rhythm, respirations, Airway, continuous pulse oximetry
  • **Interventions for Adverse Effects: ** Adjust infusion, increase IV fluids, elevate lower extremities, vasopressor agents
  • Lab Considerations: Monitor BUN, sodium, potassium, liver enzymes, glucose, calcium, magnesium levels
  • Efficacy: Effective for calm extubation in some patients, variable effectiveness

Conclusion

  • Dexmedetomidine offers distinct benefits in sedation without respiratory depression
  • Important to monitor patients closely and adjust treatment as needed