- May complicate assessment on occasions where:
- Patient has received infusions of sedative drugs as part of their critical care treatment
- Brain injury as a result of drug-induced self-harm – especially problematic when substance unknown
- Possible approaches include:
- A period of observation:
- Should approximate four times the elimination half-life of the agent involved to allow effective drug elimination
- Best suited to circumstances where short-acting agents such as propofol and alfentanil have been given to patients with normal hepatic and renal function
- Administration of specific antagonists:
- Flumazenil or naloxone may be used
- Plasma analysis:
- Can confirm that a suspected sedative is either not detected or at a subtherapeutic level
- Particularly suited for agents with long or unpredictable half-lives such as thiopental or phenobarbital.
- A confirmatory test to demonstrate the absence of cerebral blood flow/perfusion
- For example, cerebral angiography
- A period of observation:
