Ketamine for Intubation in Atrial Fibrillation with Heart Rate 180
Ketamine is acceptable and often preferred for intubation in a patient with atrial fibrillation and heart rate of 180, particularly if the patient is hemodynamically unstable or requires immediate airway management. The primary concern in this scenario is the underlying hemodynamic instability from the rapid ventricular response, not the ketamine itself.
Rationale for Ketamine Use
Ketamine maintains hemodynamic stability better than most induction agents, which is critical when a patient is already tachycardic and potentially compromised. While ketamine can theoretically increase heart rate and sympathetic tone through catecholamine release, this effect is generally modest (10-20 bpm increase) and far less concerning than the hemodynamic collapse that can occur with propofol or other sedative-hypnotics in an unstable patient.
Clinical Context and Decision-Making
The key question is whether this patient is hemodynamically stable or unstable:
If hemodynamically unstable (hypotensive, signs of shock, pulmonary edema): Ketamine is the induction agent of choice because it preserves blood pressure and cardiac output 1, 2. The tachycardia is already present and needs to be addressed separately with rate control agents or cardioversion after airway security.
If hemodynamically stable: Ketamine remains a reasonable choice, though you have more flexibility. The modest increase in heart rate from ketamine is unlikely to cause significant clinical deterioration in the short term needed for intubation 3, 4.
Addressing the Atrial Fibrillation with RVR
The atrial fibrillation with rapid ventricular response requires concurrent management, but this should not delay necessary airway management:
For hemodynamically unstable patients: Immediate electrical cardioversion is recommended after securing the airway 5, 1
For hemodynamically stable patients: IV beta-blockers (metoprolol, esmolol) or nondihydropyridine calcium channel blockers (diltiazem) are first-line for acute rate control 5, 1, 2
In patients with heart failure or reduced ejection fraction: Amiodarone or digoxin are preferred over calcium channel blockers, which can worsen hemodynamics 5, 1
Important Caveats
Do not delay intubation to achieve rate control first if the patient has a clear indication for emergent airway management. The risk of aspiration, hypoxemia, or loss of airway protection outweighs concerns about transient worsening of tachycardia during induction.
Avoid etomidate if possible despite its hemodynamic neutrality, as it provides no analgesic properties and may cause myoclonus. Avoid propofol in unstable patients as it causes vasodilation and myocardial depression that could precipitate cardiovascular collapse 1.
Consider pre-treatment with a beta-blocker (e.g., esmolol 0.5 mg/kg) immediately before induction if the patient is stable enough and time permits, as this can blunt the sympathetic response to laryngoscopy and the modest chronotropic effect of ketamine 5.
Post-Intubation Management
Once the airway is secured, immediately address the rate control:
- Beta-blockers are preferred in high adrenergic states (which intubation creates) 5, 6
- Continuous infusion of diltiazem (5-15 mg/hour) may be needed after initial bolus 1
- Avoid digoxin, diltiazem, or amiodarone if there is any concern for pre-excitation/WPW syndrome, as these can paradoxically accelerate ventricular response and cause ventricular fibrillation 5, 1