Fentanyl, Ketamine & Rocuronium: The Regimen for Trauma

An induction with fentanyl, ketamine and rocuronium is the current standard regimen for pre-hospital trauma RSI. In this step Kat Hunter (KSS HEMS Doctor) outlines the drug dosing regimens and interviews Professor Richard Lyon (KSS Director of Research & Innovation) to learn how the regimen was developed and the evidence for its benefit.

The “3:2:2” Regimen 

In trauma patients who are cardiovascularly stable and not grossly hypovolaemic, induction of anaesthesia is typically achieved with 3mcg/kg fentanyl, 2mg/kg ketamine and 2mg/kg rocuronium. This is commonly referred to as a “3:2:2” RSI and is an evolution of the more widespread “3:2:1” regime. The larger dose of rocuronium has been adopted in some services to obtain optimal intubating conditions, recognising that body weight can be difficult to estimate. A maximum induction dose of rocuronium 200mg is given, based on a maximum ideal body weight of 100kg. 

Reduced Dose Regimens

In patients suspected to have hypovolaemia and in the elderly, the dose of fentanyl and ketamine should be significantly reduced, typically to 1 mcg/kg fentanyl, 1 mg/kg ketamine and 2mg/kg rocuronium (a “1:1:2” RSI). 

In critically unstable patients, consideration can be given to omitting fentanyl resulting in an induction with 1mg/kg ketamine and 2mg/kg rocuronium (a “1:2” RSI).

In extremis, for severely hypovolaemic patients who are peri-arrest and unconscious, consideration can be given to a rocuronium only induction with 2mg/kg rocuronium.