Rescue sedation
Rarely, when immediate control of the situation is required, and first-line intramuscular sedative drugs have failed to control the situation, intramuscular rescue sedation can be considered. Intramuscular ketamine or an intramuscular benzodiazepine can be used for rescue sedation. This is in addition to the initial sedative drug used. There is a high risk of airway compromise requiring intubation if intramuscular sedatives are used in combination—always seek advice from a senior clinician.
If rescue sedation is required for an adult who is not frail or cachectic, use:
1 ketamine 4 to 5 mg/kg intramuscularly as a single dose; if the calculated dose is not within the range of 200 to 400 mg, verify dosing with a senior clinician acute severe behavioural disturbance, adult ketamine ketamine ketamine
OR if an antipsychotic was used initially
1 midazolam 5 to 10 mg intramuscularly; repeat after at least 30 minutes if required1. acute severe behavioural disturbance, adult (rescue sedation) midazolam midazolam midazolam
Lower doses may be required for adults who are frail or cachectic—seek advice from a senior clinician.
If an adult patient is being physically restrained to facilitate pharmacological management, continue restraint until a clinical response to the sedative is apparent (ie the patient is calm but rousable). Titrate any additional doses of intramuscular sedative drugs with caution because people who are restrained are more susceptible to adverse effects.
Always monitor the patient closely for potential adverse effects after administering an intramuscular sedative drug.