Ketamine for Rapid Sequence Intubation in Head Injury Patients

Introduction to Ketamine Use

Ketamine is safe and appropriate for rapid sequence intubation in head-injured patients, particularly when used in mechanically ventilated patients with controlled ventilation, as recommended by the American College of Critical Care Medicine 1, 2

Administer ketamine at 1-2 mg/kg IV for RSI, using the lower end of the dosing range (1 mg/kg) in patients with cardiovascular compromise, according to the Society of Critical Care Medicine guidelines 1, 2
The Society of Critical Care Medicine supports ketamine as a first-line induction agent alongside etomidate 2

Always administer ketamine BEFORE the neuromuscular blocking agent to prevent awareness during paralysis, which occurs in approximately 2.6% of emergency intubations, as emphasized by the Society of Critical Care Medicine 1, 3
In critically ill patients with depleted catecholamine stores, ketamine may paradoxically cause hypotension despite its sympathomimetic properties, and vasopressors should be immediately available during RSI, as recommended by the American College of Critical Care Medicine 2

The 2008 Pediatrics guidelines stated to "avoid use in patients with increased ICP," but this recommendation predates the robust evidence from 2009-2013 demonstrating ketamine's safety and ICP-lowering effects in controlled ventilation settings, as noted by the Pediatrics guidelines 4

In critically ill patients with depleted catecholamine stores, ketamine may cause hypotension and cardiac arrest despite its sympathomimetic properties, particularly in those with prolonged septic shock, severe cardiogenic shock, or adrenal exhaustion 5, 6
The Society of Critical Care Medicine suggests that ketamine can be used in hemodynamically stable patients without contraindications, with a conditional recommendation and moderate quality evidence 5, 7

Multiple observational studies demonstrate higher rates of post-intubation hypotension with ketamine compared to etomidate in certain populations, with rates of 18.3% vs 12.4% in emergency department RSI 6
Always have vasopressors immediately available during RSI with any induction agent, as post-intubation hypotension is common and associated with increased mortality, prolonged ICU stays, and organ dysfunction 6

The 2023 Society of Critical Care Medicine guidelines suggest no difference between etomidate and other induction agents (including ketamine) with respect to mortality or hypotension, though individual patient factors should guide selection 5, 7

The Society of Critical Care Medicine found no mortality difference between ketamine and etomidate in critically ill patients undergoing RSI, with no difference in vasopressor duration, and an odds ratio of 0.95 (95% CI: 0.72-1.25) 8
The Society of Critical Care Medicine advises administering a sedative-hypnotic induction agent when an NMBA is used for intubation, even in hemodynamically unstable patients with depressed consciousness 8