seizure, focal neurologic deficit, reduced level of consciousness, abnormal motor movements, hyperthermia, arrhythmias, hypotension, hypertension, coronary artery spasm, autonomic instability or other major disturbance of homeostasis.
treat aggressively aiming for a state of rousable drowsiness without causing respiratory depression
no sedation protocol is 100% safe, and thus these are only indicated when all other simpler, safer measures fail or are inappropriate, and the patient is deemed a significant risk to self or others. It is a crisis management tool.
it is critical in the initial period of physical restraint and parenteral sedation for direct visual observation of the patient's cardio-respiratory status to be maintained, and once the patient has settled sufficiently, electronic monitoring should be initiated as soon as reasonably possible to ensure patient safety.
a medical officer with advanced airway skills should remain with the patient whilst aggressive sedative Rx occurs
observations of vital signs and patient status should occur continuously in 1st 10min after parenteral sedation and every 10min for 1st 30min, then every 15min for 60min, then hourly for 4 hours after last dose or until awake
if resp. depression does occur following benzodiazepine sedation, only consider using flumazenil to reverse it if there is no evidence of concomitant pro-arrhythmic or pro-convulsant drug taken such as tricyclic antidepressants, or they are a regular benzodiazepine user, otherwise there is risk of seizures or cardiac arrest - usually safer to intubate than give flumazenil as inaccuracy of drug use history and polypharmacy tend to be issues.
Aust. Govt guidelines to Emerg. Depts 2005 for Mx of psychostimulant toxicity advise either:
protocol 1 using oral diazepam:
10-20mg o diazepam initial dose
if behavioural control or a state of rousable drowsiness is achieved within 30min of 1st dose, no more sedation needed.
insufficient clinical response by 30min, a further dose of 10mg o diazepam should be given
repeat this regime until a state of rousable drowsiness or a total of 60mg o diazepam (only exceed 60mg if no obvious resp. depression evident. Do not exceed 120mg in a 24 hour period).
protocol 2 using iv diazepam:
diazepam is the preferred agent iv over midazolam but diazepam is not suitable for im use
2.5-5mg iv diazepam initial dose
if behavioural control or a state of rousable drowsiness is achieved within 10min of 1st dose, no more sedation needed.
insufficient clinical response by 10min, a further dose of 5-10mg iv diazepam should be given
repeat this regime until a state of rousable drowsiness or a total of 60mg diazepam (only exceed 60mg if no obvious resp. depression evident. Do not exceed 120mg in a 24 hour period).
protocol 3 using im midazolam when iv access not available:
5mg im midazolam initial dose
if behavioural control or a state of rousable drowsiness is achieved within 10min of 1st dose, no more sedation needed.
insufficient clinical response by 10min, a further dose of 10mg im midazolam or 2.5-5mg iv midazolam should be given
repeat this 2nd dose for a 3rd dose if needed and if still inadequate response, resort to 2nd line.
NB. absorption of im doses is unreliable and may be delayed response - iv is preferable if iv access is possible.
2nd line
consider use of these earlier if paranoia or hallucinations are prominent
Aust. Govt guidelines to Emerg. Depts 2005 for Mx of psychostimulant toxicity advise either:
droperidol 2.5mg-5mg iv every 20min as needed to max. dose 20mg in 24hr period
preferably after checking QTc is not prolonged, and beware seizures, sudden hypotension and laryngeal dystonia
do not give to antipsychotic naive patients unless an adequate benzodiazepine regime has been exhausted
urinary alkalinisation but beware this will increase amphetamine half life
hypertension
hypertension is often transient and does not usually require Rx unless severe.
avoid beta blockers as blockade of beta 2 receptor which mediates skeletal vasodilatation may result in uncontrolled hypertension in a setting of unopposed alpha stimulation.
consider benzodiazepines if anxiety, tachycardia or hypertensive as they reduce BP and HR, and thus reduce myocardial oxygen demand in addition to their anxiolytic effects.