What is a suitable induction regimen using ketamine and rocuronium for Rapid Sequence Intubation (RSI) in patients with potential hemodynamic instability, considering past medical history and patient factors?

Ketamine and Rocuronium for Rapid Sequence Intubation

For RSI in hemodynamically unstable patients, administer ketamine 1-2 mg/kg IV followed immediately by rocuronium 1.0-1.2 mg/kg IV, with intubation attempted at 60 seconds after rocuronium administration. 1

Recommended Dosing Regimen

Ketamine Dosing

• Administer ketamine 1-2 mg/kg IV as the induction agent 1
• For patients with cardiovascular compromise or depleted catecholamine stores (prolonged septic shock, severe cardiogenic shock), use the lower end of the range (1 mg/kg) to minimize the risk of paradoxical hypotension 1
• Ketamine maintains relative hemodynamic stability through sympathomimetic properties, making it preferred over etomidate in septic patients 1

Rocuronium Dosing

• Administer rocuronium 1.0-1.2 mg/kg IV for RSI to ensure optimal intubating conditions 1, 2
• The FDA label confirms that doses of 0.9-1.2 mg/kg provide excellent or good intubating conditions in most patients within 2 minutes 2
• Give rocuronium as early as practical after ketamine to minimize apnea time 1

Timing and Technique

• Attempt intubation 60 seconds after rocuronium administration 1, 2
• Most patients achieve neuromuscular block sufficient for intubation (≥80% block) within a median of 1 minute 2
• Maximum blockade is achieved in most patients in less than 3 minutes 2

Critical Safety Considerations

Hemodynamic Management

• Have vasopressors immediately available at the bedside before initiating RSI 1
• In critically ill patients with depleted catecholamine stores (prolonged shock states, adrenal exhaustion), ketamine may paradoxically cause hypotension and cardiac arrest despite its sympathomimetic properties 1
• Recent observational data showed higher rates of post-intubation hypotension with ketamine (18.3%) compared to etomidate (12.4%) in emergency department RSI, though this likely reflects selection bias toward more unstable patients receiving ketamine 3

Medication Sequence

• Always administer ketamine BEFORE rocuronium to prevent awareness during paralysis, which occurs in approximately 2.6% of emergency intubations 4
• Never reverse this sequence, as neuromuscular blockade without sedation causes patient awareness and distress 1

Reversal Agent Availability

• Ensure sugammadex is immediately available when using high-dose rocuronium (≥0.9 mg/kg) for potential reversal in a "can't intubate, can't ventilate" scenario 1, 5

Special Population Considerations

Obese Patients

• Dose both ketamine and rocuronium based on actual body weight, not ideal body weight 1, 2
• Obese patients dosed according to ideal body weight had longer time to maximum block, shorter clinical duration, and inferior intubating conditions 2

Geriatric Patients (≥65 years)

• Use standard dosing of ketamine 1-2 mg/kg and rocuronium 1.0-1.2 mg/kg 1, 2
• Geriatric patients may experience slightly prolonged clinical duration (median 46-94 minutes depending on dose) but do not require dose reduction 2

Pediatric Patients

• Rocuronium 0.6 mg/kg is recommended for pediatric RSI under sevoflurane/isoflurane anesthesia 5, 2
• Rocuronium is NOT recommended for rapid sequence intubation in pediatric patients per FDA labeling 2
• For children under 8 years, administer atropine 0.01-0.02 mg/kg IV (maximum 0.5 mg) before induction to prevent bradycardia 5

Common Pitfalls and How to Avoid Them

Pitfall #1: Inadequate Preoxygenation

• Position patient in semi-Fowler position (head and trunk elevated) to improve first-pass success and reduce aspiration risk 1
• Use high-flow nasal oxygen when challenging laryngoscopy is anticipated 1
• Use noninvasive positive pressure ventilation in patients with severe hypoxemia (PaO2/FiO2 < 150) 1

Pitfall #2: Premature Intubation Attempt

• Wait the full 60 seconds after rocuronium administration before attempting intubation 1, 2
• Attempting intubation before adequate neuromuscular blockade increases risk of patient coughing, aspiration, and failed first-pass attempt 1
• Consider using a peripheral nerve stimulator to confirm adequate blockade if uncertain 1

Pitfall #3: Assuming Ketamine is Always Hemodynamically Safe

• Ketamine's sympathomimetic effects depend on endogenous catecholamine stores 1
• In patients with prolonged critical illness, severe septic shock, or adrenal exhaustion, ketamine can cause profound hypotension 1
• The Society of Critical Care Medicine found no mortality difference between ketamine and etomidate overall, suggesting individual patient factors should guide selection 1, 4

Pitfall #4: Inadequate Medication Preparation

• Prepare vasopressors (norepinephrine or phenylephrine) and have them ready for immediate administration 1
• Verify sugammadex availability before administering high-dose rocuronium 1, 5
• Store rocuronium with cap and ferrule intact to minimize risk of accidental administration 2

Contraindications and Relative Contraindications

For Ketamine

• Patients with severely depleted catecholamine stores may experience paradoxical hypotension 1
• While historically avoided in head injury, current evidence supports ketamine safety in mechanically ventilated head-injured patients with controlled ventilation 4

For Rocuronium

• No absolute contraindications for RSI use 2
• Use caution in patients with neuromuscular disorders where prolonged blockade may occur 2

Alternative Considerations

While the question specifically asks about ketamine and rocuronium, it's worth noting that:

• Etomidate 0.3 mg/kg IV is an alternative induction agent with favorable hemodynamic profile, though it may cause transient adrenal suppression 1
• Succinylcholine 1-1.5 mg/kg IV is the first-line neuromuscular blocker when no contraindications exist, with faster onset than rocuronium 1
• The Society of Critical Care Medicine found no mortality difference between etomidate and ketamine in critically ill patients (OR 0.95% CI 0.72-1.25) 4