Clinical Scenarios & Adjuncts in IV Induction

Choosing the right IV induction agent hinges on patient factors and clinical context. Let’s explore scenario-based use and adjuncts:

Scenario-Based Indications

1. Hemodynamic Instability (e.g., Septic Shock, Cardiac Compromise):

   • Etomidate: First-line for RSI (minimal BP impact).
   • Ketamine: Alternative in hypovolemia (supports BP via catecholamine release).
   • Avoid propofol (profound hypotension).

2. Increased Intracranial Pressure (ICP):

   • Propofol: Reduces cerebral metabolism/ICP.
   • Avoid ketamine (may ↑ ICP).

3. Bronchospasm/Asthma:

   • Ketamine: Bronchodilatory effects.
   • Propofol: Secondary option (mild bronchodilation).

4. Pediatrics:

   • Propofol: Standard for children >3 years.
   • Ketamine: Preferred for distressed children or those with respiratory illness.

Adjuncts During Induction

• Opioids (e.g., Fentanyl, Remifentanil):

  • Blunt sympathetic response to laryngoscopy.
  • Reduce propofol dose (mitigate hypotension).
  • Caution: Remifentanil may cause chest wall rigidity.

• Lidocaine:

  • Reduces propofol injection pain.
  • Attenuates airway reflexes during intubation.

• Muscle Relaxants (e.g., Rocuronium, Succinylcholine):

  • Essential for optimal intubating conditions in RSI.

Pro Tip: In RSI, combine etomidate (0.2–0.3 mg/kg) + fentanyl (1–2 mcg/kg) + rocuronium (1.2 mg/kg) for hemodynamic stability and rapid paralysis.