Term
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Definition
1) amnesia - occurs through depressing neuronal activity
2) immobility in response to noxious stimuliation - inhibiting concious brain activity or nerve reflexes;
3) attenuation of autonomic response to noxious stimuli |
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Term
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Definition
| use of multiple drugs to achieve desired depth of aneshtesia |
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Term
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Definition
| barbiturates, diazepam, midazolam, atropine (blocks ACh effect on heart), 5-HT3 receptor antagonist (ondansetron - prevent vomiting), H-2 antagonist (ranitidine - acid reflux) |
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Term
| Intravenous GAs - sodiuim thiopental [Pentothal], propofol [Diprivan], etomidate [Amidate], ketamine [Ketalar] |
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Definition
| used to induce anesthesia - faster acting |
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Term
| Inhaled GAs - nitrous oxide [N2O], halothane [Fluothane], isoflurane [Forane], enflurane [Ethrane], desflurane [Suprane], sevoflurane [Ultane] |
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Definition
| used to maintain anesthesia; have unpleasant odor and may irritate air passageways; can constantly be monitored |
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Term
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Definition
| neuromuscular junction blocker used as needed for GA; mainly for endotracheal intubation |
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Term
| fentanyl, other analgesics |
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Definition
| used to reduce dose of GAs and specifically block noxious stimulus reflex in autonomic nervous system |
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Term
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Definition
| condition where half-concious pts exhibit restlessness, crying, moaning, and thrashing; pts often have HTN and tachycardia as a result of rebound effect from effects of GAs wearing off |
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Term
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Definition
| drug given to reduce shivering threshold when coming out of general anesthesia |
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Term
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Definition
| avoid these drugs until effects of GAs have worn off |
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Term
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Definition
| MOST important factor affecting inhaled GAs |
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Term
| high water solubility = slow induction |
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Definition
| it takes a long for inhaled GA to first dissolve in blood before entering CNS |
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Term
| low water solubility = rapid induction |
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Definition
| inhaled GA is NOT soluble in blood & rapidly goes from blood to CNS |
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Term
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Definition
poorly soluble in blood (partition coefficient = 0.47) AND low lipid solubility --> rapid induction, fast acting, AND not very potent;
MAC = 105%; by itself it cannot achieve desired depth of anesthesia; colorless, odorless gas --> used to induce analgesia in dentist office;
SEs: middle ear air pockets may expand; depresses ventillary response to hypoxia; does NOT trigger malignant hyperthermia |
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Term
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Definition
inaled GA;
MAC = 0.75%; MOST POTENT; no pungent odor;
very soluble in blood (partition coefficient = 2.3)--> slowest induction --> slowest recovery;
SEs:
20-25% decrease in BP; vasodilation; decreased CO, bradycardia; decrease renal blood flow; muscle relaxation; decrease ventilation rate; hepatitis |
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Term
| Minimum Alveolar Concentration (MAC) |
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Definition
| meausres potency; the concentration of inhaled GA needed for 50% of pts to NOT respond to pain |
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Term
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Definition
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Term
| MAC is proportional to Lipid Solubility |
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Definition
| high lipid solubility --> greater potency (MAC); low lipid solubility --> lower potency (MAC) |
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Term
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Definition
inhaled GA still used in 3rd world countries; cheap & effective;
SEs: irritates airways, flammable
High water AND high lipid solubility = slow-acting AND very potent |
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Term
| MAC for Maintenance of Anesthesia |
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Definition
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Term
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Definition
inhaled GA; major anesthetic in US from 30's to 60's;
SEs: "spontaneous combustion" on operating table; highly flammable |
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Term
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Definition
inhaled GA
MAC = 1.6%; sweet odor;
Partition coeffecient = 1.8 --> slower induction;
SEs:
decrease BP, decreased cardiomyocyte contractility, peripheral vasodilation; electrical seizure activity (C/I for epilepsy); muscle relaxation (enhanced with NMJ blockers); decrease in ventilation rate |
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Term
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Definition
inhaled GA
MAC = 1.2%; pungent odor;
Partition Coefficient = 1.4 --> medium induction;
>99% eliminated unchanged via lungs;
SEs: decrease in BP, vasodilation, mild tachycardia, decreased renal blood flow, muscle relaxation (enhanced with NJM blocker)
Preferred GA for neurosurgery; |
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Term
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Definition
inhaled GA
MAC = 6%;
irritating gas --> coughing, respiratory secretions, MUST USE IV GA to induce anesthesia;
Partition coefficient = 0.45 --> rapid induction;
SEs:
decreased BP, ventilation rate; tachycardia |
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Term
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Definition
inhaled GA
MAC = 2%; reacts with dried out soda lime to produce CO;
Partition coefficient = 0.65;
SEs: decreased BP, systemic vasodilation;
Preferred GA for pts prone to myocardial ischemia;
Short term renal damage (Compound A formation) |
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Term
| sodium thiopental [Pentothal] |
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Definition
IV GA;
Induction dose: 3-5 mg/kg;
Induction time = 1 min
Duration of action = 5-8 min;;
Initial drug used in current lethal injection protocol;
LD50 = 50 mg/kg;
pH = 10-11 --> drug precipitation if mixed with acidic drugs;
MoA: barbiturate;
SEs: decrease brains metabolic rate, decreases BP, vasodilation, decreases heart contractility, decreases ventilation rate; "hangover" effect if injected multiple times |
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Term
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Definition
IV GA;
induction dose: 1.5-2.5 mg/kg;
Duration of ACtion: 4-8 min;
NOT water soluble --> VERY lipid soluble (use w/ caution in pts w/ high triglycerides);
Most common induction agent;
LACK of hangover effect;
Allows pts to be discharged faster, good for outpatient procedures;
MoA: enhances effects of GABA at GABA-A receptors;
SEs: MAJOR decrease in BP, vasodilation, decraase in myocardial contractility; decrease in ventilation rate; anti-emetic properties; does NOT cross placenta (safe for pregnant women) |
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Term
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Definition
IV GA;
Induction dose: 0.2-0.4 mg/kg
Duration of action: 4-8 min
NOT water soluble;
Used for pts at risk for hypotension;
Used for induction & maintenance of anesthesia;
SEs:
myoclonic movements (tx w/ benzodiazepines); nausea, vomiting; |
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Term
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Definition
IV GA;
Induction dose: 0.5-1.5 mg/kg;
Duration of Action: 10-15 min
WATER SOLUBLE;
produces PROFOUND analgesia;
used in military, battlefield;
MoA: NMDA competetive antagonist, inhibition of Na, K channels;
SEs: increased cerebral blood flow, EMERGENCE DELIRIUM (1 hr post emergence), hallucinations, vivid dreams, illusions; modest decrease in ventilation, potent bronchodilator; incrrease BP, CO, HR --> risky for pts with hypotension |
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Term
| benzodiazepines - midazolam >>> diazepam > lorazepam |
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Definition
can produce anesthesia but at doses that would result in prolonged amnesia & sedation;
Give IV, oral, rectal, or IM;
Uses: Pre-op sedation; |
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Term
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Definition
| water soluble benzodiazepine; no pain on injection site; more rapid onset (2 min IV), rapid recovery |
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Term
| opioids - fentanyl (100x more potent than morphine) |
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Definition
potent analgesics; Given at induction for later intubation, initial incision;
Minimizes vascular reflex to noxious, painful stimuli;
SEs: nausea, vomiting; decreased ventilation rate, decreased HR, decrease in BP |
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Term
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Definition
| 100x more potent than morphine; used in Russian hostage/terrorist actions; duration of action: 30 min; |
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Term
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Definition
| shortest duration of action (10 min) of opioids |
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Term
| alpha-2 adrenergic agonist - dexmedetomidine |
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Definition
approved for sedation in critically ill pts; off label use as GA adjunct;
IV use only; useful in non-intubated pts |
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Term
| alpha-2 adrenergic agonist - dexmedetomidine |
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Definition
approved for sedation in critically ill pts; off label use as GA adjunct;
IV use only; useful in non-intubated pts |
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Term
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Definition
core body temp < 36 degrees C; due to exposed body cavities, IV fluid at room temp, vasodilation of skin, normal room temp is 21 or colder;
Warming efforts:
heated surgical beds, heat air that is inhaled with GA, water-filled garments with microprocessor control of body temp. |
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Term
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Definition
core body temp reaches 42 degrees C with muscle rigidity; can occur in most GAs and some NJM blockers;
Mechanism: ryanodine Ca channels do NOT close --> uncontrolled muscle contraction leading to heat generation --> myocytes lyse releasing K causing fatal cardiac effects;
Tx: dantrolene (Dantrium) - ryanodine receptor inhibitor, also used to tx muscle spasms |
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Term
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Definition
| ryanodine receptor inhibitor; also used to treat spasms; used to treat malignant hyperthermia due to GAs |
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