What is the recommended drug strategy for intubation in a patient with hypotension (low blood pressure)?

Drug Strategy for Intubation in Hypotensive Patients

Use etomidate (0.2-0.4 mg/kg IV) as the induction agent for rapid sequence intubation in hypotensive patients, as it provides superior hemodynamic stability compared to all other agents. 1, 2

Induction Agent Selection

Etomidate is the first-line choice for hemodynamically unstable patients based on the Society of Critical Care Medicine's 2023 guidelines, which found no mortality difference between etomidate and other agents while demonstrating the most favorable hemodynamic profile. 1, 2

Evidence Supporting Etomidate in Hypotension:

• In patients with pre-intubation systolic blood pressure <100 mmHg, etomidate actually increased blood pressure by 12.1 mmHg systolic and 7.3 mmHg diastolic immediately post-intubation, with stability maintained throughout the 15-minute post-intubation period. 3

• Etomidate causes significantly less hypotension than alternative agents: only 3.6% of patients developed hypotension with etomidate versus 19.5% with midazolam. 4

• The 2023 SCCM guidelines explicitly state there is no difference in the incidence of hypotension or vasopressor use between etomidate and other induction agents. 1

Alternative: Ketamine

If etomidate is contraindicated or unavailable, use ketamine at the lower end of the dosing range (1 mg/kg IV rather than 2 mg/kg). 2, 5

• Ketamine's sympathomimetic properties theoretically maintain blood pressure, but evidence shows higher rates of peri-intubation hypotension compared to etomidate (18.3% vs 12.4%, OR 1.4). 2

• Critical caveat: In critically ill patients with depleted catecholamine stores (sepsis, prolonged shock), ketamine may cause paradoxical hypotension despite its sympathomimetic properties. 2, 5

Neuromuscular Blocking Agent

Administer succinylcholine 1-1.5 mg/kg IV as the first-line paralytic when no contraindications exist. 2, 5

• If succinylcholine is contraindicated, use rocuronium 0.9-1.2 mg/kg IV with sugammadex immediately available for reversal. 2, 5

Critical Sequencing

Always administer the sedative-hypnotic agent (etomidate or ketamine) BEFORE the neuromuscular blocking agent to prevent awareness during paralysis. 2, 5, 6

• The American Heart Association recommends titrating etomidate in 20 mg increments every 10 seconds until loss of consciousness rather than rapid bolus. 2

Adjunctive Vasopressor Strategy

The 2023 SCCM guidelines state there is insufficient evidence to recommend for or against peri-intubation vasopressors or IV fluids in hypotensive patients undergoing RSI. 1

However, in clinical practice for patients with very low blood pressure:

• Consider having a vasopressor infusion prepared and ready before intubation. 7

• Epinephrine infusion can be started at 0.05 mcg/kg/min and titrated to achieve desired mean arterial pressure, with adjustments every 10-15 minutes in increments of 0.05-0.2 mcg/kg/min. 7

• Post-intubation hypotension is common and associated with increased mortality, prolonged ICU stays, and organ dysfunction. 6

Common Pitfalls to Avoid

• Do not use midazolam in hypotensive patients: Even low doses (2-4 mg) cause a 10% decrease in mean systolic blood pressure and result in hypotension in 19.5% of patients. 4

• Do not administer corticosteroids following etomidate: The 2023 SCCM guidelines recommend against giving corticosteroids to counteract etomidate-induced adrenal suppression, as the transient adrenal suppression does not translate to clinically significant outcomes. 1, 8

• Do not assume ketamine is safer in shock: Despite theoretical benefits, ketamine was associated with more hypotension episodes in trauma patients (45% vs 33%) when compared to periods of liberal etomidate use. 9

• Ensure adequate paralysis before laryngoscopy: Use a peripheral nerve stimulator if uncertain about blockade adequacy to prevent coughing or movement that worsens hemodynamic instability. 2

Positioning Consideration

Use semi-Fowler position (head and torso inclined) during intubation rather than supine positioning, as this improves first-pass success and reduces aspiration risk while potentially improving hemodynamics through increased functional residual capacity. 1