Anesthesia - Total Flashcards
NAme the different forms of anesthesia and the drugs used for them.
IV = Propofol, Ketamine, Etomidate, Dexmedetomidine etc
Inhaled Anesthetics: Isoflurane, Desflurane, SEvoflurane, Nitrous
Sedatives: Midazolam and Diazepam
Narcotics/Opioids: Morpine, Fentanyl etc
Local Anesthetics: Lidocaine and Bupicavaine
Muscle Relaxants: Succinylcholine or Rocuronium
Others: Antiemetics, Anticholinergics, Reversal agents
Name the 4 IV Anesthetic agents (non-barbituate or benzodiazepine).
Of those, which ones cause Respiratory Depression and need skilled airway technicians and which ones can be given outside of OR (like ER/ICU)?
Which ones cause bronchodilation? (therefore good for asthmatics and smokers)
Names: Propofol, Ketamine, Etomidate, and Dexmedetomidine
Propofol can cause POTENT respiratory depression/apnea and also suppresses upper airway reflexes and so is good for Bronchoscopy/Upper Endocopy procedures and instrumentation of the airway and causes Bronchodilation
vs
Ketamine*, Etomidate*, and Dexmedetomidine cause minimal respiratory depression (*if infused slowly); Ketamine and Demedotmidine good for ER/ICU
Ketamine causes Bronchodilation (good for asthmatics) but also increased secretions so give with **Glycopyrrolate **
Name the 4 IV Anesthetic agents (non-barbituate or benzodiazepine).
Of those, which ones cause Cardiovascular depression/instability?
Names: Propofol, Ketamine, Etomidate, and Dexmedetomidine
ETOMIDATE = good for CV stability!!! Use for Trauma and Cardiac patients
vs
Propofol causes vasodilation and hypotension
Ketamine causes Increased Sympathetic tone - Increased HR, BP, CO and Myocardial Oxygen use - **DO NOT USE WITH CAD or cardiac patients **
Dexmedeotimidine causes CV depression, bradycardia and hypotension - **DO NOT USE with CV pts or in Kids where CO depends on HR **
Name the 4 IV Anesthetic agents (non-barbituate or benzodiazepine).
Of those, which ones are good for Neurosurgery/brain patients? Which ones cause CNS effects and what are those effects?
Names: Propofol, Ketamine, Etomidate, and Dexmedetomidine
Propofol decreases CBF, CMRO2, ICP, is anti-convulsant and neuroprotective = IDEAL for neurosurgery patients with TBI, Tumor or seizure
vs
Ketamine - Increase CBF, CMRO2 and causes siezuers - DO NOT USE in TBI/neurosurg
Etomidate - decrease CBF and CMRO2 but causes Myoclonus/Seizuers in 50% pts
vs
Dexmedetomidine - sedation and analgesia with no real changes in CMRO2 or ICP
Name the 4 IV Anestetic agents (non-barbituate or benzo) and their mechanism of action.
Which ones have analgesic effects?
Propofol and Etomidate = Potentiates the opening GABA Type A receptor Chloride channel to decrease AP propogation in Post-synaptic neuron
Ketamine = NMDA receptor antagonist (stops binding of Glycine and Glutamine which are excitatory) to decrease POst-synaptic AP firing AND causes increased catecholamine release
Dexmedetomidine = A_lpha2 Adrenergic Receptor Agonist_ that acts in Locus Ceruleus to decrease NE release and firing in SC and Brain
Ketamine and Dexmedetomidine have analgesic effects!
Propofol - uses, metabolism and effects.
Warning?
Pros and Cons
- Made with soybean, glycerol and lechicin -<strong> EGG ALLERGY!</strong>!! and Needs sterile technique
- Metab in Liver and excreted via Kidney but pts wake up in 8-10 after bolus from **Redistribution **
- used for induction, maintenance, and sedation (repeat boluse for dental procedure)
- good for Tumor/TBI/Seizure neurosurg patients and for bronchoscopy/endoscopy bc stops Airway reflexes
EFFECTS: Neuroprotective, CV depression (hypotension), Resp depression but with bronchodilation, Anti-emetic
WARNING: PIS = lactic acidosis with long term infusion -do not use in ICU
Pros: amnesia, fast on/off, ant-emetic, neuroprotective, bronchodilation
Cons: Pain with injection, no pain relief, cardiac and respiratory depression, Egg allergy, PIS
Ketamine - uses, metabolism, effects
Warning?
Pros and Cons
- Used for induction (can be IM), maintenance, Sedation (for short pain procedures like burn dressing changes), and post-op pain (abdominal, thoracic, ortho) and chronic pain - _Sedative/Dissociative and Analgesic _
- Metab to Nor-ketamine (less active metab) in Liver and excreted ~3 hours
- CAN INCREASE CATECHOLAMINES - vasoconstriction and bronchodilation
Given with Midazolam for Emergence Reaction and Glycopyrrolate for Secretions
NOT for Neurosurgery pts or pts with CAD or CV patients. Good for asthmatics.
- Effects: Dissociative, can cause seizures, Emergence reaction/hallucinations, increased Sympathetic tone and Myocardial depression in critically ill pts
PROS: Analgesia (good for chronic pain and narcs), MINIMAL Resp depression, can be given IV/IM/Rectal/Oral/Epid, Bronchodilation
CONS: Emergence delerium (combat with Midazolam), Increased resp secretions (combat with Glycopyrrolate), HTN + Tachycardia and then cardiac depressio in ill pts, Increased ICP and Seizures (not for TBI pts)
Etomidate - uses, metabolism, effects
Warnings?
Pros and Cons
- used for Anesth Induction in Unstable CV patients
- Metab by Ester Hydrolysis; peak to brain in 1 minute - fast but then into urine/bile in 2-5 hrs
WARNING: ADRENOCROTICO SUPPRESSION with just 1 dose: blocks 11beta hydroxylase from converting cholesterol to cortisol and so really sick ICU pts can’t have life-saving stress response afterwards
Effects: CV stability, minimal resp depression, Decreased CBF and CMRO2 but causes Myoclonus in 50% pts
PROS: CV stability and minimal resp depsession
CONS: Pain on injection, Seizures!!!, Adrenocorticosuppression - not for ICU PTS!!!, Myoclonus (rigity and so have to time correctly with muscle relaxants for intubation)
Dexmedetomidine - uses, metab, effects
Warnings?
Pros and Cons
- used for sedation for procedures and as general anesthesia bc decreses doses for inhaled and analgesics
SOME ANALGESIA
Effects: CNS sedation and analgesia but no changes in ICP etc, CV depression (hypotension and bradycardia - NOT used for CV pts or Kids), Minimal Resp depression
Pros: sedation and analgesia, no respiratory depression
Cons: hypotension, bradycardia, Longer onset and Duration
What are the Benzodiazepines? How are they used? Metabolised? Mechanism? Effects?
Midazolam and Diazepam both bind to specific sites on GABA receptor and increase affinity of receptor for GABA leading to increased hyperpolarization of post-syn neuron and decreased AP firing
Metab - in liver and Midaz to inactive metabolite and Diazepam to 2 active metabolites which is why it causes the Hangover Effect and has longer half-life
- They have rapid onset into BBB and are off with Redistribution
- Midaz can be taken lots of ways but diazepam is only oral
Used for Pre-Op anxiety or Amnesia, Sedation in short procedures, and seizure suppression
Effects: CNS - sedation, hypnosis, Amnesia, antoconvulsant, decreased CMRO2 and blood flow; Resp - minimal resp depression; CV - lowers TPR and BP (midazolam more) but no real changes in CO
What are the BArbituates? Special Features? Metabolism? Effects? Uses?
Warning!
Thiopental and Methoheital are salts that mix with water to make Alkaline pH solutions (pH>10) and bind to GABA A receptors and increase affinity for GABA.
Metabolized in Liver and have INDUCTION effects and are cleared more rapidly with inducers (ex. takes longer to put down an Alcoholic with Thiopental)
- Precipitates with Acid in IV lines
Used for Induction and neuroprotection for putting pts in coma with increased ICP or Focal Ischemia
Effects: CNS - sedation, anesthesia, *DECREASE Pain threshold!!!, decrease CBF, ICP, CMRO2 (can cause coma/flatline); CV - decrease BP and vasodilation thats exagerated in elderly, CV disease, and hypovolemia pts; Resp - decrease minute ventilation, Tidal volume, RR, and responses to hypercapnea/hypoxia but no suppression in airway reflexes; PAIN on injection and GANGRENE if injected into arteries (can lose hand/feet)
WARNING: DO NOT USE IN ACUTE INTERMITTENT PORPHYRIA
- stimulate D-ALAS synthesis of Heme and pts with AIP can’t convert the final step of Porphyrinobilinogen to Heme and so it builds up and get hallucinations, psychosis, numbness, abdominal pain etc
What is the common moiety for all of the volatile anasthetics?
Ether
What are the general effects of Inhaled Volatile Anesthetics? what do they all cause?
Unconsciousness, Amnesia, Immobility
BRONCHODILATION!
Vasodilation and hypotensoion that’s particularly bad in sick patients who can’t recover from it
What is MAC? Significance? Use?
MAC = concentration of anesthetic to stop movement in 50% of patients
GOAL = MAC 1
At MAC .5 Amnesia
At MAC 1.2 or 1.3 can get dangerous (CV failure and coma)
**IN GENERAL: Increase MAC then Decrease Potency and MACs are additive **
**Measure of Potency essentially **
What is the blood gas partition coefficient and what does it mean?
Measure of solubility of the gas in blood (trends are generally applicable to tissues as well)
Lower Number = Less soluble
N2O < Des < Sev < Iso
Iso is most soluble - therefore takes the longest for emergence
Nitrous and DES are least soluble in all tissues
