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11 Cards in this Set
- Front
- Back
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What are the volatile anesthetics used?
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NO (gas)
volatile liquids: halothane, enoflurane, isoflurane, desflurane, seroflurane |
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What is minimal alveolar concentration?
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measure of potency of volatile anesthetics; steady-state alveolar concentration necessary for 50% of the population not to respond to stimuli
MAC decreased with age, narcotics and increased temperature |
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How does increased solubility affect volatile anesthetic uptake? What else does uptake depend on?
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increased solubility --> decreased uptake.
also depends on inspired concentration, alveolar ventilation, cardiac output (increase --> decreased uptake), alveolar-venous concentration gradient |
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What's the CV AE of volatile anesthetics?
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myocardial sensitization to catecolamines and decreased myocardial contractility
halothane: decreased HR, decreased CO, increased BP, same PVR also massive hepatic necrosis enflurane: increased HR, decreased CO, decreased BP, decreased PVR, less sensitive to cats also renal failure if existing kidney disease seroflurane: decreased PVR --> decreased BP no sensitization isoflurane: increased HR, decreased BP, same CO, large decrease in PVR desflurane: increased HR, decreased BP, small decreased CO |
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What are the respiratory AE of volatile anesthetics?
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decreased bronchial smooth muscle tone
decreased pulmonary vascular resistance inhibit hypoxic pulmonary vasoconstriction decrease mucociliary function decreased TV and increase respiratory frequency decreased response to CO2 blocks ventilatory response to hypoxia |
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nitrous oxide (N2O)
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MAC = 120% = low potency = can't be used by itself
used with IV narcotics, barbs, muscle relaxants not metabolized -- breathed out irreversibly binds vitamin B12 -->BM suppression if used several days slight myocardial depression and increased PVR don't use if pt has a pneumothorax |
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What are the IV agents used for general anesthesia?
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ketamine, propofol, etomidate, narcotics
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ketamine
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IV, IM, po
CNS effects: blocks muscarinic-R and NMDA-R. opiate agonist. causes dissociation amnesia (may have movements) AE: increased ICP, emergence reactions and hallucinations CV effects: myocardial depressant but is made up for by sympathetics (if working) increased BP and HR resp effects: minimal! normal response to CO2, relaxed bronchial smooth muscles, increased pharyngeal and laryngeal pressure |
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propofol
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IV
more rapid and clear recovery than barbiturates, less N/V than barbiturates continuous infusion soybean fat emulsion --> bacterial growth; discard within 6 hours |
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etomidate
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IV, nonbarbiturate hypnotic
minimal CV effects (good for pts with low ejection fraction) reverrsible adrenocortical suppression |
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malignant hyperthermia
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1/100,000 anesthesiaas, autosomal inheritence
RyR1 mutation (Ca++ channel) --> uncontrolled intracellular Ca++ release --> tachycardia, hyperthermia, hypercapnia, muscle rigidity, metabolic acidosis tx: dantrolene (muscle relaxant) associated with volatile anesthetics and succinylcholine |
