Intravenous and Inhalational Anesthesia Flashcards
What is the triad of anesthesia
Analgesia
Amnesia
Skeletal Muscle Reaction
Significance of no anasthesia specific antagonists
Rely on metabolism of the drugs
What are the four stages of anesthesia
1 - Analgesia
2 - Disinhibition (Delirium and Excitement)
3 - Surgical Anesthesia
4 - Medullary Depression (Resp + CV depression)
Minimum Alveolar Concentation is…
Minimum alv. conc. that stops movement in 50% of patients in response to painful stimulus.
Used to define potency of inhalational anesthetics
Relationship of N20 and mac
itself – 104%
combinew ith others to lower the MAC of other anesthetics
Some non-drug factors that lower MAC
Increasing Age Hypothermia CNS depression/Drugs Acute OH intox Pregnancy Alpha Adrenergic (clonidine)
Things that increase MAC requirements
Hyperthermia
Chronic Ethanol Abse
Increase CNS neurotransmitters (MAO inhib.)
Blood-Gas Partition Coefficient is a measure of…
the relative solubility of a drug in blood vs air. Determines the uptake from the alveoli
______ Blood Solubility will cause slow induction? Rapid Induction?
Low Solubility – Rapid Induction
High Solubility – Slow Induction
Important Nitrous Oxide details
Insoluble,
Analgesia + Sedation
Second Gas Effect
Adverse effects of Nitrous Oxide
Oxidizes Cobalt in B12
Expansion in Closed Spaced
Diffusion hypoxia on emergence
Important Diethyl Ether facts
Flammable, easy to administer
Respirator Irritant
Complete Anesthetic (Relax, unconscious, analgesia)
Advantages of Halothane
Sweet odor, smooth inhalation
Fair analgesia, muscle relaxation
Excellent hypnosis
Disadvantages of Halothane
CV, respiratory depression
Catecholamine Sensitization (ventricular arrythmia)
Hepatotoxicity (genetic predisp., massive necrosis)
Important Enflurane details
Rapid Induction and Recovery
Good Analgesia/relaxation/hypnosis
No catecholamine effect
Bad odor, CNS stim (seizures), CV depression
Important Isoflurane details
Rapid Induction/Emergence
Good analgesia/sedation
Pungent odor, drops BP, coronary steal
Important Sevoflurane details
Rapid Induction
Non irritating
Non-flammable
CANNOT USE WITH LOW FLOW ANES.
Important Desflurane details
Rapid achievement of anesthesia, recovery/awakening
Uterine relaxant
Drops in CO, BP
CV effects of Anes.
Drop MAP (HE drops CO, others drop SVR) Alter HR (Halo decreases via vagal, other increase)
Resp. effects of anethetics
decrease TV, increase rate
impaired mucociliary apparatus
Bronchodilation (esp. Halothane)
CNS effects of anes.
Lower CNS metabolic rate
May increase intracerebral pressure
Enflurane can trigger seizures
Renal effects of anes.
Decrease GFR, RPF, inc. filtration frac.
Enflurane, Sevoflurane, Methoxyflurane can be nephrotoxic
Most potent anesthetic given
Methoxyflurane
Important detail on cycloflurane
Explosive
Important details on Malignant Hyperthermia
- Ca+ in SR released –> HTN, Tachy, hyperthem, acidosis, hyperkalemia
- Trigger by Halogenated agent or succinylcholine
- Treat w/ IV Dantrolene Sodium
Important Sedative Hypnotics for this exam
Barbiturates Ketamine Propofol Etomidate Benzos
Clinical Uses of Barbiturates
Induction of anesthesia
Treatment of Increased ICP
Decreased Cerebral Blood Volume
Decrease Cerebral Metabolism
5 most common Barbs in anesthesia
Sodium Pentathal (Thiopental) Methohexital Thiamylal Secobarbital Pentoparbital
Important Sodium Pentothal details
Sedation+Hypnosis+Anesthesia IV adinistration Rapid onset, short duration NO muscle relaxation, antanalgesic Resp depression, cough, bronchospasm
Important Ketamine details
PCP derivative, NMDA antag.
Rapid Onset, Short Duration
Profound anterograde amnesia for 1 hr, analgesia
Copious salivation
Increases Intracranial Pressure, Don’t give w/ head injury
Relationship of Ketamine to autonomics
Sympathomimetic (blocks reuptake)
Smooth muscle relaxant
Details about Ketamine Emergence Delirum
Auditory Hallucinations
Vivid Dreams
Reduced by benzos
Important propofol details
IV, rapid onset, short duration hypnosis
Sedation, hypnosis, anesthesia, antiemetic
No analgesia.
Pain on injection, hypotension, drop in SVR
Important details on Etomidate
NON - Barb, analgesic
Pain on injection, myoclonus
Adrenal suppression w/ chronic
N/V
Mechanism of Benzos in anesthesia
increased C- GABA activity
Diminished Reticular Activating System
Antagonized by Flumenazil
Common Benzos in anesthesia
Diazepam (Vallium)
Lorazepam
Midazolam (versed)
Important details on Diazepam (Vallium)
Rapidly absorbed from GI
Minimal CV depression
Protein binding paralleling lipid solubilty
Clinical uses of Diazepam
Preoperative Induction of anesthesia (w/ large dose) IV sedation anticonvulsant/muscle relaxant delirum tremens
Important details of Midazolam (versed)
More rapid, potent than valium
50% first pass effect
Elimination half time = 1-4 hrs
Excellent anterograde amnesia
Midazolam downside
CV depression (esp. w/ narcotics)
Lorazepam details
More potent amnestic than diazepam
Slow onset, long duration, slow dissociation
Minimal effects on muscle, CV, pulm
Pharmacologically inactive metabolites
