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Flashcards in propofol Deck (30)

what is the classification of propofol?



what is the equilibration 1/2 time of propofol?

1-3 min


what are uses of propofol?

-induction and maintenance of general anesthesia
-combine with sedation and regional anesthesia
-adjunct for MAC or TIVA


what is the MOA of propofol?

inhibits neuronal activity at the post synaptic GABA receptors by increasing chloride conductance into cell
-GABA's natural function is to reduce activity of neurons
-acts via ion mediated receptors (chloride): chloride influx increased, preventing depolarization
*hyperpolarization of post synaptic membrane inhibits neuronal activity
*gives desired hypnosis and sedation effects


describe onset of propofol

-rapid onset of action d/t high lipid solubility


describe metabolic clearance of propofol

-rapid clearance
-short half life: 2-8 min of initial dose
-hepatic clearance
-30-60 ml/kg/min cleared (changes if hepatic blood flow altered)
-metabolites excreted renally (but renal failure does not affect clearance of parent drug)


when should propofol not be given in relation to clearance?

-hepatic failure
-absolutely no urine output
*can be given with renal failure


what are CV effects of propofol?

-decrease in arterial BP r/t drop in SVR (elderly, speed of injection, large doses)
-vagal like effects (drop in HR & BP) can lead to asystole,


what increases the risk of asystole or other hemodynamic instabilities occurring with propofol?

-prone to oculocardiac reflex (aka vagal ocular reflex)
*eyes surgery, visceral/peritoneal tugging
-pre-existing impair ventricular function (significant drop in CO)
*decreases ventricular filling pressures
*decreases contractility
*SVR= (MAP-CVP)/CO x 79.9


what are respiratory effects of propofol?

-profound ventilator depressant (apnea after induction doses and sometimes after sedation doses)
-inhibits hypoxic drive (normal response to hypercarbia is altered)
-upper airway reflexes are depressed more than with thiopental
*great for use with LMA and intubation (no spasm)
-some histamine release but less than barbiturates and ketamine (don't use in asthmatics with ACTIVE bronchospasm or wheezing)
*can give to asthmatics with no s/s of constriction
*large doses used with status asthmaticus, rationale being large dose will overcome bronchospasm


what are neurologic effects of propofol?

-decreases ICP and CBF
-significant drop in CPP (MAP-ICP) with elevated ICP
*normal 80-100 mmHg
*critical reduction of CPP (< 50 mmHg
*sustained CPP <25 results in irreversible brain damage
-suppresses memory by inhibition of post-synaptic neurons
-decrease intraocular pressure
-excitatory phenomena (muscle twitiching, spontaneous movement, hiccups) YET breaks status epilepticus
*avoid use in pts with known seizure hx (not contraindicated)
*predominant anticonvulsant effects


what are some drug interactions with propofol?

-old formulations potentiated actions of NDMBs (newer do not)
-slight synergistic effect with midazolam
-opioids have faster onset and total dose required may be lower
-asystole episodes increased with opioids


what are contraindications of propofol use?

-egg and soybean allergies (not true contraindication, but caution and avoid if can)
-not approved for OB use
-markedly increased ICP
-avoid in severe CAD pts. (hypotension)
-not approved for pediatric ICU sedation
-some newer formulas may contain sulfites (sulfa allergy)
-prior sensitivity or unexplained reaction to propofol
-inexperienced airway management personnel
-rapid bolus in the elderly and debilitated


describe important sterile technique with propofol use

-composition supports bacterial growth
-administration should be completed within 6 hrs
*death and severe sepsis has been associated with contamination
*ampules should be used within 6 hrs even if containing sulfites


what are complications of propofol?

-pain on injection: changes in pH from preservatives
-allergic reactions (allergy to NMB increases)
-seizure activity (should consider it an allergy)
-infection from contamination (supports growth of E.Coli and Pseudomonas A. and Candida A)
-crosses placenta
-abuse potential
-mood changes
-introvert to extrovert behavior
-amorous behavior


what should be done to help pain on injection with propofol?

-sedation/versed as well as opioids help to reduce pain


what are certain triggers associated with propofol induced seizures?

-epileptic history or family history
-movement disorders
-history of prior propofol admin
-allergy to NDMB
-history of chemical dependency
-heightened emotional state prior to surgery
-presence of hyperventilation or fever
-fast rate of propofol admin


what are primary benefits of propofol?

-antiemetic (inhibits CTZ)
-smooth induction
-decreased airway reflexes especially upper airway
-may help with pruritis
-break status epilepticus
-analgesic properties


what is the general induction dose of propofol?

1-2.5 mg/kg


what is the induction dose of propofol for healthy adults?

2-2.5 mg/kg


what is the induction dose of propofol for elderly or debilitated pts.?

0.5-1.5 mg/kg over 30+ sec


what is the induction dose of propofol for cardiac and neuro cases?

cardiac: 0.5-1.5 mg/kg
neuro: 1-2 mg/kg


what is the induction dose of propofol for pediatrics?

2-3 mg/kg over 20-30 sec


what is the initial dose of propofol for a MAC case?

0.5 mg/kg in a healthy adult
*reduce in 1/2 for elderly and debilitated


what is the dose of propofol for ICU maintenance of a ventilated pt.?

-initial: 0.3-0.6 mg/kg/hr and titrate
-additional 10-20 mg boluses as needed


what is the MAC propofol infusion rate for mild, moderate, and heavy sedation cases?

mild: 25 mcg/kg/min
moderate: 50 mcg/kg/min
heavy: 75-100 mcg/kg/min


compare propofol to thiopental and ketamine

-rapid onset and quick clearance
-smoother induction
-can be used for maintenance
-potential to induce seizures
-pain on injection
-more seizure protective
-more organ protective (brain)
-slower awakening time and longer sedative effects
-less pain on injection
-some histamine release
-increased sleep time (than propofol)
-contraindicated in seizures, spinal cord, and brain injury, significant cardiac disease, and hypermetabolic states
-increased NV
-reduced respiratory depression
-less pain on injection
-increased salivation


describe fospropofol (Aquavan)

-prodrug of propofol
-not approved for general, but approved for sedation/MAC cases
-takes more drug than propofol to produce same effect to loss of consciousness
-delayed time to peak concentrations, wake up may be delayed


what is fospropofol metabolized to?

-propofol, formaldehyde, phosphates
*formaldehyde: carcinogenic; however, the amount present is said to be scant and equivalent of that present after other drugs are metabolized


how does effective dose of fospropofol compare to propofol?

2.5 mg/kg propofol compares to 12.5 mg/kg of fospropofol