Drugs commonly used

Question 1

What are the uses of propofol?

Answer 1

Induction of anaesthesia
Sedation during intensive care and regional anaesthesia and can be used for…
Procedural sedation
Refractory nausea and vomiting in chemotherapy
Status epilepticus

Question 2

What is propofol?

Answer 2

Phenol derivative; 2,6-diisopropylphenol

Question 3

What is the molecular weight, pKa and acid-base status of propofol?

Answer 3

Molecular weight 178.27
Weak organic acid
pKa = 11

Question 4

is propofol lipid soluble or insoluble?

Answer 4

Highly lipid soluble

Question 5

How does propofol come?

Answer 5

Oil-in-water emulsion of 1% propofol in soybean oil, egg lecithin, benzyl alcohol to prevent microorganism inoculation, glycerol and sodium hydroxide to adjust the pH.

Question 6

What is the main effect of propofol and how does it work?

Answer 6

Hypnotic
No-one really knows how it works but it potentiates the inhibitory transmitters glycine and GABA (to different mechanisms than thiobarbiturates and benzodiazepines) and may reduce sodium channel opening times

Question 7

How is propofol given and in what dose for induction of anaesthesia?

Answer 7

IV and bolus of 1.5-2.5mg/kg

Question 8

What rate should propofol be run at for maintenance of anaesthesia as an infusion?

Answer 8

4-12mg/kg/hr

Question 9

How do you adjust propofol dosing for children?

Answer 9

Increase induction dose by 50% and maintenance infusion by 25-50%

Question 10

How do you adjust propofol dosing for elderly on unstable patients?

Answer 10

1-1.5mg/kg induction and 3-6mg/kg/hr infusion

Question 11

How does co-induction use of an opioid or benzodiazepine impact the dose of propofol required for induction?

Answer 11

Will reduce the dose required

Question 12

Propofol will render a patient unconscious within what time after injection?

Answer 12

30-40 seconds

Question 13

How long does it take to begin emergence from propofol as a single dose?

Answer 13

Approximately 10minutes

Question 14

What plasma concentration of propofol will produce hypnosis or sedation respectively?

Answer 14

Hypnosis; 2 - 6micrograms/ml

Sedation; 0.5-1.5micrograms/ml

Question 15

What effects does propofol have on the cardiovascular system?

Answer 15

15-25% decrease in the systemic vascular resistance and blood pressure, 20% reduction of cardiac outflow. Attenuates response to laryngoscopy in fit health patients.

Question 16

How does propofol reduce SVR?

Answer 16

Stimulates production of NO

Question 17

Propofol has a bradycardic effect which can be quite profound. How is it caused?

Answer 17

Possibly resets the baroreceptor reflex and may lead to asystole.

Question 18

What effect does propofol have on the respiratory system as a bolus?

Answer 18

Can induce apnoea of variable duration (30 - >60seconds) and suppresses laryngeal reflexes.

Question 19

What effect does propofol have on the respiratory system as an infusion?

Answer 19

Decreases tidal volume, causes tachypnoea and a decreased ventilatory response to both hypercarbia and hypoxia. Also causes bronchodilator and may preserve the mechanism of hypoxic pulmonary vasoconstriction.

Question 20

What effect does propofol have on the CNS?

Answer 20

Smooth rapid induction and rapid clear headed emergence.
Intracranial pressure, CPP and cerebral oxygen consumption decrease.
10% of patients may develop dystonic movements due to excitatory effects. Not associated with seizure activity and can be used to treat status epilepticus. Vivid dreams, some with a sexual nature. Intraocular pressure is decreased.