Week 3: General Anesthesia & Neuromuscular Blockers

general anesthetics

patient unconsious, more extensive surgery

local anesthetics

patient conscious, needed in small, defined areas

general anesthesia causes absence of

perception of all sensations

general anesthesia administration

inhalation or IV meds, allows for precise control

3 main goals of general anesthesia

rapid onset, rapid and uneventful recovery, amnesia of events

pre op meds during general anesthesia

anti nausea, decrease bronchial secretions, decrease gastric acid

pre anesthesia meds

barbiturates, benzodiazepines, opioids

during anesthesia meds

inhaled gas, iv med, neuromuscular blockers

4 main sedatives

barbiturates, benzodiazepines, opioids, antihistamines

barbiturates

decrease anxiety, used to be used more but now replaced by propofol

benzos

decrease anxiety and tension

opioids

analgesia and sedation

antihistamines

side effect used of sedation

4 main anti-nausea/vomitting drugs

anti histamines, steroids, serotonin antagonists, anticholinergics

med to decrease bronchial secreitons

anticholinergics

med to decrease gastric activity

h2 blockers

main types of inhaled general anesthetics

enflurane, halothane, isoflurane, nitrous oxide (short procedures)

main types of IV meds in general anesthetics

propofol (short procedures and sedation in ICU), ketamine, thiopental, etomidate

inhaled anesthetics

gas or volatile liquids mixed with air/o2 and inhaled into lungs, elimination through lungs

propofol

short acting, induces anesthesia.

-recovery can be rapid so good for early mobility

-good for sedation icu pts that are critically ill

etomidate

rapid onset of general anesthesia with minimal cardiovascular side effects

ketamine

dissociative anesthesia, detached from surroundings, appears awake but unable to recall

-used in short procedures, invasive kid surgery, older adults, or those with low bp

ketamine mechanism of action

inhibits NMDA receptor, used off label for depression or party drug

common reaction when emerging from ketamine

disorientation, excitation, hallucinations

adverse effects of ketamine

htn, respiratory depression, ICP

neuromuscular blockers are used when

skeletal mm paralysis is necessary, allows for proper positioning and preventing spontaneous contractions

because the thoracic wall becomes compliant under neuromuscular blockers, it is easier for

mechanical ventilation

2 types of neuromuscular blockers

depolarizing, non depolarizing

blockers work at

neuromuscular junction and impacts acetylcholine

side effects of neuromuscular blockers

tachycardia, increased histamine release, hyperkalemia, residual mm pain and weakness, anaphylaxis

serious complication of neuromuscular blockers

residual paralysis (need to be admitted to ICU)

when patients are critically ill and on ventilaters, what are used to sedate and paralyze them

general anesthetics and NM blockers via IV drip

for early mobility but using general anesthesia, they

stop iv meds, wake up, do PT, restart meds (sedation vacation)

metabolism for general anesthetics

liver

elimination of general anesthetics

lungs if inhaled, kidneys if IV

if patient has any liver or lung disease, elimination is

delayed and they have longer periods of confusion

main 6 adverse effects of general anesthetics

dizziness, nausea, vomiting, sedation, muscle rigidity, rigors

what are rigors

cold with shivering, and fever

rehav concerns

lingering effects (mm weakness/woozy), bronchial secretions accumulate(get them moving), may have side effects for days( older, comorbidites), long term effects on memory (cognitive disorders, older adults)