Komiskey General Anesthesia Flashcards
Preanesthetic for sedation
Pentobarbital
Preanesthetic to prevent allergic rxns
Diphenhydramine
Preanesthetic for nausea
Ondanestron
Preanesthetic to provide analgesia
Fentanyl
Preanesthetic to knock out memory, prevent bradycardia, and fluid secretion
Scopolamine
Preanesthetic muscle relaxant reason
Facilitation of intubation
Speed of induction of anesthesia is dependent on
Inspired gas partial pressure
Ventilation rate
GA solubility- less soluble GAs equilibrate more quickly
What’s MAC
Minimum Alveolar concentration Equilibrium concentration required to prevent response to pain in 50% of pts Easy comparison of anesthetics Easily measured Important critical endpoints Consistent and reproducible
MAC is increased by
Hyperthermia Elevated CNS catecholamine NT release Chronic alcohol use Acute cocaine use Hypernatremia
MAC is decreased by
Hypothermia Pregnancy Shock Increasing age Acute alcohol ingestion CNS depressant drugs Decreased CNS neurotransmitter release
Nitrous oxide
MAC>100 incomplete anesthetic Good analgesia Rapid onset and recovery No metabolism Megaloblastic anemia may occur
Halothane
Not pungent -used in children
Medium rate onset and recovery
Sensitizes the heart to epi induced arrhythmias
Rare halothane induced hepatitis
Desflurane
Most rapid onset of action and recovery
Widely used for outpatient surgery
Irritating to the airway in awake patients and causes coughing, salivation, and bronchospasm
Used for maintenance of anesthesia
Sevoflurane
Very low blood gas partition coefficient w relatively rapid onset of action and recovery
Widely used for outpatient surgery
Not irritating to airway
Useful induction agent
Isoflurane
Medium rate of onset and recovery
Used for induction and maintenance of anesthesia
Damage to mitochondria
Methoxyflurane
Obsolete
Slow onset and recovery
Extensive hepatic and renal metabolism -renal dysfunction
Halogenated GA toxicity used with succinylcholine
Malignant hyperthermia
Give Dantrolene
Anesthetic associated with nausea and vomiting
Most likely associated with intravenous anesthetics
N20 is greatest culprit and isoflurane is least likely to cause nausea
Ondanestron -5ht3 antagonist
Avoidance of n20
Ketorolac vs opioid for analgesia
Droperidol, metaclopromide, dexmethasone -dopamine agonsit
Thiopental
Most freq used barbiturate Ultra short acting drug- long elimination half life Anesthetic lasts 5 minutes - most commonly used induction agent Rapid unconsciousness, good amnesia, bad analgesia Poor muscle relaxation Pleasant induction for the patient MOA: GABA A agonist
Thiopental organ system effects
CNS: reduces cerebral blood flow, intracranial pressure- protects brain against hypoxic/ischemic injury
Cardiovascular: bp, output decrease, hypotension
Heart rate increased
Depress respiration
Benzodiazepines
Excellent anxiolytics, anticonvulsants, muscle relaxants
Binds to distinct spot on GABA a receptor
Water soluble in vial, then in plasma becomes unionized, increased lipid solubility
CNS: raises seriousness threshold, anterograde amnesia
Cv: hypotensive and minimal depression
Opioids
Analgesic with hypnotic action, no amnesia
Used for premedication, induction, and maintenance of anesthesia and postoperative pain control
Pruritis
Chest wall rigidity
Patients forget to breathe
Ketamine
MOA: non competitive NMDA antagonists- inhibits of stimulatory neuronal system
Dissociative anesthetic
CNS: fast acting antidepressants, increases intracranial disease
Nystagmus, increased tracheobronchial and salivary excretions
Not too bad in heart and lungs
Etomidate
Imidazole derivative CNS: lowers cerebral blood flow and metabolic rate Minimal lung depression Minimal cardiovascular Myoclonus
Propofol
Very potent, action at GABA a complex, may enhance Cl- conductance at glycine -reduces cerebral blood flow+metabolism Decreased CV effects Fast acting Euphoric
Dexmedetomidine
Brain (locus ceruleus) spinal cord, and autonomic nerves
Sedation, anxiolysis, analgesia
Decreased bp and hr , decreased release of NE
Alpha 2 agonist
Preanesthetic to reduce anxiety
Midazolam and diazepam
