Propofol

Question 0

What is the drug classification of propofol? what is used for? What other drug is in this family?

Answer 0

Drug classification: Isopropylphenol
Used as a hypnotic
other drug: Fosppropofol

Question 1

What is propofol used for? What are the dosages

Answer 1

1. Induction of GA (1-2.5 mg/kg)
2. For maintenance of GA (100/200 mcg/kg/min)
3. for conscious sedation (25-75 mcg/kg/min)
4. antiemetic (10-20 mg) or 10 mcg/kg/min)

Question 2

What are the physiochemical characteristics of propofol?

Answer 2

Chemical: diisopropylphenol
Physiologic: Insoluble in aqueous solution
It is made as an emulsion, soy bean, lecithin, glycerol.
It supports bacterial growth—> use within 6 hours of openings (sepsis and death has been associated to contaminated Propofol use.

Question 3

What are the pharmacokinetics of propofol? How is it eliminated?

Answer 3

Distribution: Highly lipophilic—> rapid CNS effect followed by re-distribution into more inactive tissue sites
Metabolized: Hepatic metabolism is partial oxidation by CY4503A4 but mostly by CYP450 2B6. Propofol is metabolized into water soluble compounds. Rate of metabolism of Propofol exceeds hepatic blood flow indicating an extrahepatic means of plasma clearence. 30% of bolus is cleared by lungs.
Eliminated: Through Kidneys

Question 4

What if the wake up time after an induction dose of propofol? what is the onset of action?

Answer 4

duration: 8-10 min
onset: 30 sec to a min

Question 5

Why is propofol a good candidate for continuos infusion?

Answer 5

1. Rapid plasma clearence
2. Slow re-distribution from poorly perfused compartments back to central compartment
3. brief context sensitive half life

Question 6

what are the pharmacodynamics of propofol?

Answer 6

Binds to GABAa (Y subunit) opens chloride channel and causes hyperpolarization of cell membrane, no subsequent action potential

Question 7

what are the effects of propofol on central nervous system?

Answer 7

1. Decrease in CBF
2. Decrease in cerebral oxygen consumption
3. Decrease in intercranial pressure
4. Neuroprotective
5. Anticonvulsant

Question 8

What are the effects of propofol on cardiovascular system?

Answer 8

1. Causes vasodilatation both in arteries and veins
2. Decreases pre-load
3. Does not affect cardiac output
4. Numbs the baroreflex effect of heart, heart rate will not pick up in response to decrease in bp
5. Watch out in elderly as they are already hypovolemic too and now you are causing vasodilation

Question 9

What are the effects of Propofol on respiration?

Answer 9

1. It is a respiratory depressant
2. Induction dosecauses apnea
3. Infusion will reduce min ventilation by reducing the tidal volume and respiratory rate ( effects tidal volume more)
4. Ventilatory response to hypoxia and hypercapnia is reduced
5. Reduction in upper airways reflex—> you can use LMA with propofol
6. decreases the incidence of wheezing after induction of anesthesia both in healthy and asthmatic patients

Question 10

What are the other effects of propofol?

Answer 10

1. Antiemetic (10-20 mg, 10 Mcg/kg/min)
2. DOES NOT enhance the effect of NMBD
3. Provided excellent clinical condition for ET without NMBD

Question 11

What is propofol infusion syndrome?

Answer 11

unexpected tachycardia during propofol anesthesia should require lab eval for possible metabolic acidoisis

Question 12

what is porpofol used for?

Answer 12

1. induction ( 1-2.5 adults) (2.5-3.5 kids)
2. Maintenance (100-200 mcg/kg/min)
3. conscious sedation (25-75 mcg/kg/min)
4. anti-emetic (10-20 mg, 10 mcg/kg/min)

Question 13

When do you need to reduce the amount of propofol given?

Answer 13

1. increasing age
2. Reduced cardiovascular reserve
3. premed with benzodiazepines and opiods

Question 14

what is one of the major side effects or propofol?

Answer 14

pain on injection

Question 15

what is fospropofol?

Answer 15

It is water soluble prodrug of propofol

2. It is sterile, water-soluble colorless and clear solution
3. comes as 35mg/ml
4. trade name luserda

Question 16

How is fospropofol compared to propofol?

Answer 16

it is the prodrug thus it takes longer for it to onset and to be eliminated

Question 17

Propofol infusion syndrome

Answer 17

Propofol infusion syndrome (PRIS) is a rare syndrome which affects patients undergoing long-term treatment with high doses of the anaesthetic and sedative drug propofol. It can lead to cardiac failure, rhabdomyolysis, metabolic acidosis, and renal failure, and is often fatal.[1][2][3] Hyperkalemia, hypertriglyceridemia, and hepatomegaly, proposed to be caused by either “a direct mitochondrial respiratory chain inhibition or impaired mitochondrial fatty acid metabolism” [4] are also key features. It is associated with high doses and long-term use of propofol (> 4 mg/kg/h for more than 24 hours). It occurs more commonly in children, and critically ill patients receiving catecholamines and glucocorticoids are at high risk. Treatment is supportive. Early recognition of the syndrome and discontinuation of the propofol infusion reduces morbidity and mortality.

Question 18

Propofol infusion syndrome

Answer 18

Propofol infusion syndrome (PRIS) is a rare syndrome which affects patients undergoing long-term treatment with high doses of the anaesthetic and sedative drug propofol. It can lead to cardiac failure, rhabdomyolysis, metabolic acidosis, and renal failure, and is often fatal.[1][2][3] Hyperkalemia, hypertriglyceridemia, and hepatomegaly, proposed to be caused by either “a direct mitochondrial respiratory chain inhibition or impaired mitochondrial fatty acid metabolism” [4] are also key features. It is associated with high doses and long-term use of propofol (> 4 mg/kg/h for more than 24 hours). It occurs more commonly in children, and critically ill patients receiving catecholamines and glucocorticoids are at high risk. Treatment is supportive. Early recognition of the syndrome and discontinuation of the propofol infusion reduces morbidity and mortality.