What are the considerations for using ketamine in patients with Chronic Obstructive Pulmonary Disease (COPD)?

Considerations for Using Ketamine in COPD Patients

Ketamine can be beneficial in COPD patients due to its bronchodilatory properties, but should be used with appropriate precautions regarding increased secretions and cardiovascular effects. 1

Potential Benefits

• Ketamine causes bronchodilation, which may be particularly beneficial for patients with COPD, especially during acute exacerbations or procedures requiring sedation 1
• Maintains spontaneous ventilation, which can help avoid intubation and mechanical ventilation in patients with compromised respiratory status 2
• Provides hemodynamic stability through its sympathomimetic effects, which can be advantageous in hemodynamically compromised COPD patients 1
• May help preserve the CO₂ response curve, which is important in patients with chronic CO₂ retention 2

Important Precautions

• Ketamine increases upper airway secretions, which can potentially worsen respiratory symptoms in COPD patients 1
• Premedication with anticholinergics (atropine or preferably glycopyrrolate) is recommended to reduce secretions when using ketamine in COPD patients 1
• Ketamine produces a dose-dependent increase in heart rate, blood pressure, and cardiac output through sympathetic stimulation 1
• Should be avoided in COPD patients with comorbid ischemic heart disease, cerebrovascular disease, or hypertension due to these cardiovascular effects 1

Clinical Evidence

• A case report demonstrated successful use of ketamine anesthesia in a patient with severe COPD and CO₂ retention undergoing pericardial window procedure, maintaining hemodynamic stability without requiring intubation 2
• However, a randomized controlled trial showed that ketamine was not associated with greater improvement in airway resistance compared to fentanyl in patients with severe acute bronchospasm 3
• A recent study (2023) found that continuous ketamine infusion during thoracic surgery in COPD patients improved arterial oxygenation (PaO₂/FiO₂) and decreased shunt fraction during one-lung ventilation 4

Practical Recommendations

• Consider ketamine in COPD patients requiring sedation when:

  • Avoiding mechanical ventilation is a priority 2
  • Bronchodilation would be beneficial 1
  • The patient is hemodynamically compromised 1

• Dosing considerations:

  • For procedural sedation: 1 mg/kg IV bolus followed by 0.5 mg/kg/h infusion has shown benefit for respiratory parameters in COPD patients 4
  • Always administer with an anticholinergic agent to reduce secretions 1

• Monitor for:

  • Increased secretions requiring suctioning 1
  • Cardiovascular effects (increased heart rate, blood pressure) 1
  • Emergence reactions (can be reduced by co-administration with midazolam) 1

Special Situations

• In COPD patients with pericardial tamponade, ketamine may be particularly useful as it maintains spontaneous ventilation while providing hemodynamic stability 2
• For COPD patients requiring one-lung ventilation during thoracic surgery, ketamine infusion may improve oxygenation parameters 4
• In patients requiring deep sedation for respiratory distress, ketamine may have propofol-sparing effects and reduce vasopressor requirements 5