Sedation Flashcards
Define conscious sedation
A technique in which the use of a drug or drugs produces a state of depression of the CNS enabling treatment to be carried out, but during which verbal consent is maintained throughout the period of sedation. The drugs used carry a margin of safety wide enough to render the loss of consciousness unlikely.
The level of sedation must be such that patient remains conscious, retains protective reflexes and is able to understand and respond to verbal commands.
What drug is used for inhalation sedation and for who?
Nitrous oxide/oxygen
For children <12, young adults and adults 16+
What drug is used for intravenous sedation and for who?
Midazolam
For young adults and adults
What are the indications for conscious sedation?
Psychosocial:
- anxiety, phobia, severe gag reflex, persistent fainting
Dental:
- prolonged/traumatic procedure, implants
Medical:
- conditions aggravated by stress, IHD, hypertension, asthma, epilepsy, UC and Crohns, mild to moderate special care cases
What are the contraindications for conscious sedation?
Social:
- unwilling, unaccompanied, very old or young
Dental:
- procedures too difficult or long in duration, spreading infection
Medical:
- severe or uncontrolled systemic disease, severe mental/physical disability, narcolepsy, COPD, pregnancy and lactation
What drugs can increase sedation affects?
Alcohol Opiods Erythromycin Antidepressants Antihistamines Antipsychotics Recreational drugs
What medical assessment is needed for pre-sedation?
Blood pressure
BMI
Heart rate and oxygen sat levels
ASA status
What are the main 2 assessments of anxiety?
Modified dental anxiety scale (>19=phobia)
Index of sedation need
What are the 6 ASA classes?
Class 1
- NormaL healthy patient
Class 2
- patient with mild systemic disease
Class 3
- patient with severe systemic disease
Class 4
- severe systemic disease that is a constant threat to life
Class 5
- moribund patient who is not expected to survive without operation
Class 6
- declared brain dead whose organs are being removed for donor purposes
What is the action of midazolam?
Midazolam is a benzodiazepine which acts on receptors in the CNS to enhance effects of GABA in the cerebral cortex and motor circuits and inhibits CNS neurotransmitters.
It crosses BBB and is water soluble
What is the half life and sedation window for midazolam?
Half life 1.5-3hrs
Sedation window 10-40mins and has fast recovery period
How is midazolam metabolised?
By the liver and has extra hepatic metabolism so is less affected by liver disease and other drugs so more reliable
What are the main effects of midazolam?
Anxiolysis Sedation Muscle relaxant Anterograde amnesia Respiratory depression
What is the treatment regimen for using midazolam for sedation?
1mg bolus over 30secs, wait 90sec and assess response then give a further 1mg every 30-60secs and continually assess response.
Max 1mg bolus at a time
2-10mg is generally most effective amount
What is the reversal agent for midazolam and the regimen?
Flumazenil
- 500ug/5ml: dose 200ug then 100ug increments every 60secs
How does flumazenil work?
It acts as both an antagonist and antidote to benzodiazepines through competitive inhibition
How much oxygen should be given via nasal cannula or Hudson mask?
Nasal cannula 2ml/min
Hudson mask 5ml/min
What is Verill and Eve’s signs?
Verill’s sign
- partial ptosis of upper eyelid
Eves sign
- unable to touch nose with finger
What post op instructions are given to patients following sedation?
Must be escorted home and looked After for 24hrs
Do not drive, cook or operate machinery for 24hrs
Do not make important decision including signing documents/phone calls and banking
Do not take alcohol or sleeping medication
Not be responsible for others
Do not return to work for atleast 24hrs
When carrying out inhalation sedation, the oxygen stops working who do you report this to?
MHRA
