IV Anesthetics Flashcards
compare the contributions of distribution and metabolism to the duration of IV anesthetics
distribution- terminates the effects of most anesthetics; determines early rise and decline of anesthetics*
metabolism- plays a small role in termination of effects
describe organ system effects for thiopental and midazolam
thiopental- reduces cerebral metabolism, and O2 utilization, reduces cerebral blood flow, protects brain against hypoxic injury; BP may drop transiently; lowers contractility; resp depression
midazolam- reduction in cerebral met and blood flow; hypotension, amnestic dose gives minimal resp depression
describe organ system effects for ketamine and etomidate
ketamine- dreams, hallucinations, delirium, increased ICP, antidepressant; myocardial depressant; increased HR, BP, Epi levels due to sympathetic stimulation; bronchodilation, nystagmus
etomidate- lowers cerebral blood flow and ICP; minimal resp depression- lower risk of apnea; does NOT block sympathetics, best for hemodynamic stability desire of CV px
describe organ system effects for propofol
reduced cerebral blood flow; decreased BP, HR, and CO; central venous pressure unchanged;
the vessel-rich compartment
brain, heart, lungs, liver, splanchnics
the fat compartment has what type of volume and flow?
high volume, low flow
the muscle compartment has what type of volume?
intermediate (compared to vessel-rich group)
describe the distribution of IV anesthetic in the body compartments chronologically
drug goes to the brain and viscera of the vessel-rich group, then also gets high blood flow out to lean muscles, then the last metabolically low key fat starts to pick up more of the dose
truth serum; long elimination half life: what terminates its effect?
thiopental
REDISTRIBUTION*
clinical uses of thiopental
general anesthetic induction; brain protection
best amnestic agents
midazolam* and lorazepam (benzos)
uses of benzos: midazolam
premedication before anesthesia, conscious or heavy sedation, induction of anesthesia, anti convulsant
opioids are not reliable for..
amnesia; only analgesia *
uses of opioids
premedication, maintenance of anesthesia, post op pain control
effects of opiods
pruritis- nose and whole body; chest wall rigidity (sympathetics), apnea