Anesthesia Flashcards
Pre-Op Eval for Anesthesia
- includes what specifics
- the airway exam includes what
Eval.
- full ROS
- allergies, meds
- exercise tolerance
- relevent family hx. and previous anesthesia & outcome
- review labs/imaging/consulation/tests
- PE: airway eval.
- ASA class designation
Airway Exam
- Mallampati score
- condition of feeth and length of incisors
- neck mobility and length and thickness
- tongue size
- facial hair
- thyromental distance
- ability to protrude jaw
mallampati score for the mouth and soft plalate eval.
Cormack-Lehane grade for the view of vocal cords
ASA Scores
I: normal healthy individual
II: mild disease without much limitation
example = smoker, social drinker, well controled DM/HTN
III: patient with systemic severe disease
example: poor control DM/HTn, COPD, BMI > 40 , heaptitis, ESRN, MI,CVA or CAD
IV: severe sytemic disease that is life threatening
example: recent MI/CVA/TIA, stents/CAD, severe ARDS, ESRD
V: moribound pt. not expect to survive without this operation
example: AAA rupture, massive trauma etc.
VI: organ harverst
E added if its an emergency procedure
Anesthesia
- 3 phases
specifics of Induction
Phases
- induction
- maintenance
- emergence
Induction = sequence of events to ease pt. to sleep/sedated
- pre-oxygenate them
- administer induction agent (the sleep med.)
- test lash reflex
- mask ventilate them to make sure it works
- adminsiters paralytic (stop breathing and msucles)
- intubate
RSI
- those with risk of aspirating (full stomach emergency)
- skip the vent test (taht could bring stuff back up)
- apply cricoid pressure
- use fast acting paralytic: succinylcholine and rocuronium
- intubate
Maintenance & Emergence Phase of Anesthesia
maintain anesthesia
- inhalation agent (volatile agents)
- propofol drip (TIVA)
- or both
treat pt. responsed through surgery & pain
maintain paralysis, watch fluids and hemodynamics
Emergence
- reverse paralytics
- give antiemtics
- turn off anesthesia
- get pt. to breath spon.
- remove airway device
what is MAC: Monitored Anesthesia Care
MAC: “sedation” cases
MAC can be combined with other anesthesias like…
- regional
- spinal
- epidural
Patient’s ability during MAC
- breathing on their own (through NC or airway)
- patient may move: in response to pain if not locally anesthetized
- pt. are “asleep” and dont remember
Benzodiazepines: for anesthesia use
- what are they
- specifics of midazolam
Benzos
- activate GABA in CNS: cause hyperpolarization and decreased excitiability
Pharm effects
- anti-anxiety
- sedation
- anterograde amnesia
- anticonv.
- muscle relax
- watch respirtory depression, hypotension and pain with injection
Midazolam
- used for amensia and anxiolytic
- anti-anxiety in prep and holding
- sendation for nerve blocks and line placements
- helpful adjuct for when heavy anesthesia cant be used
- caution in neruo and elderly pt
- REVERSAL AGENT = FLUMAZENIL
Agents Used for Induction: Propofol
Propofol
- most common induction agent
- can also be used to maintain anesthesia (TIVA)
- “milk of amensia” since its white and lipid-like
Uses
- GA induction and maitenance
- MAC
- subhypnotic infuction (to prevent PONV)
Side effects
- apnea, decreasd TV, mocard. depression and myoclonus
- vasodilation, hypotension
- pain when injected: give lidocaine
- hiccups
Agents used for Induction: Etomidate
Etomidate
- used to induce anethesia: minimal effect on cardiovascular function: thus HR, CO, SVR, PAP, BP remain unchanged
- good for trauma and bad heart pt.s
Side Effects
- more PONV than propofol
- pain on injection
- HPA axis suppression for a few hours
Agents used of Induction: Ketamine
Ketamine
- dissciative amensia
- rarely used: but could be : this is the only agent WITH analgesic properties
USes
- ERAS protocol
- chornic pain
- those with opiod misuse disorder
- commonly an adjuct with GA
Effects
- no significant respiratory depression
- hallucinations, out of body effect (give with medazolam)
- salivation, increade HR and BP and ICp = side effects
Inahled Anesthestics
halogenated hydrocarbons
- create immobility (SC) and amnesia (in brain)
Minimum Alveolar Concentration (MAC) of inhaled
- concentration required to suppress movement in approx 50% of pt.
- allows use to understnad how much is needed
How they work
- intake in the lungs & to circulation & elminiated via lungs
- speed of induction and speed of emergence depend on tissue cncentration, minute ventilation and CO
Inahled Anesthetics: common ones
Sevoflurane
Desflurane
Isoflurane
Sevoflurane
- MC
- also a bronchodilator : can be used
Desflurane
- fast on/off but can irritate lungs
- $$$
- less potent
Isoflurane
- slower on/off
- good for cardiac surg.
side effects of volatile anesthesics
- hypotension (vasodilation)
- increased RR and decreased TV
- bronchodilation
- airway irritation
- muscle relaxant
- hepatic injury
- increase ICP if > 1 MAP
- can interfer with evoked potentials of neuro monitoring
Malign
use of Nitric Oxide gas
use in conjunction with other anesteic gases cannot be a single agent
Use
- will increasethe amount of the other gas in the lung to increase effectiveness = second gas effect
Watch out of
- expansion of airpockets elsewhere in body (bowel, brain, vessels)
Malignant Hyperthermia
a skeletal muscle disorder: ryanodine receptor = uncontrolled release of Ca2+ from SR
this triggers a hypermetabolic syndrome = death
- mucle contration/rigitiy
- rhambdo.
- metabolic and respiratory acidosis
- hypercarbia & tachycardia
- hyperthermia
- hemodynaic intability
Triggered by
- halogenated anesthesics
- succinylcholine
Signs
- unresponsive to increase MV with creeping up ETCO2
- tachycadia and pnea
- HTN
- muscle rigitiy + masster spasm
- hyperthermia (last sign)
Treatment of malignant Hyperthermia
- stop the surgery
- filter Co2
- hyperventilate
- IV dantrolene or ryanodex reconstitued
- ABGs
- bicarb for acidosis
- active cooling
- treat hyperkalemia and dysarrithmias
