Lecture 1 Flashcards
anesthesia
chemically initiating and maintaining loss of sensation in a patient while maintaining hemodynamic stability in order to allow the surgical team to complete their task
goals of anesthesia (5)
1) antinociception
2) amnesia
3) akinesia
4) hemodynamic stability
5) unconsciousness
antinociception
no pain
amnesia
no memory
akinesia
no movement
hemodynamic stability
stable BP and HR
unconsciousness
“going to sleep”
phases of anesthesia
1) preoperative
2) intraoperative
3) postoperative
preoperative phase definition
all necessary steps prior to delivery of anesthesia including
intraoperative phase definition
patient is in the operating room
intraoperative phase steps
preinduction
induction
maintenance
cessation of surgery/anesthesia
preoperative phase steps
- testing (labs, EKG, echo, respiratory)
- evaluation of anesthetic plan
- patient consent
- place lines (catheters, A lines, IV)
- premedication (anxiolytic, analgesic, antiemetic, antibiotics)
- workspace setup
intraoperative phase monitoring devices
pulse ox (heme-bound O2)
blood pressure
temp
EKG
preoxygeneation
- AKA denitrogenation
- increases patients ability to sustain apnea
- fills reservoir of O2 in lungs allowing time to intubate w/o desaturation
safe apnea time period definition
time it takes for patient to reach 88-90% saturation
preoxygenation safe apnea time period
up to 11 min (high)
typically 9 for healthy adult
preoxygeneation methods
1) 100% O2 for 3 min
2) 8 deep breaths of 10 LPM O2 at 100%
Induction definition
delivery of drugs to patient to achieve necesssary anesthetic plan
3 methods of induction
1) IV
2) Mask
3) Ketamine dart (IM)
Rapid Sequence Induction
- decreases time between loss of airway reflexes and intubation
- reduces likelihood of patient aspiration
RSI candidates
Full stomach patients
- trauma
- non-NPO emergency
- pregnant
- bowel obstruction
- appendectomy
- morbidly obese
- diabetic w/gastroparesis
gastroesophageal reflux disease
RSI general steps
- preoxygenate thoroughly
- IA dose (propofol)
- succinylcholine (rapid acting MR)
IV induction advantages
faster = safer (10-20s)
less prolonged excitatory phase = decreased risk of laryngospasm and aspiration
IV induction disadvantages
rapid loss of airway protective reflexes and airway patency
Mask induction advantages
no iv needed prior to anesthetic
Mask induction disadvantages
slower
prolonged stage II phase
Mask induction (peds dose)
4 LPM N2O + 2 LPM O2
sevoflurane at 8%
IM induction
“ketamine dart”
4-6mg ketamine IM
21 ga 1 1/2” needle
IM induction advantages
useful for non-compliant patient
IM induction disadvantages
non-compliant patient can cause injury to themselves/others
Basic Positions
supine
prone
lateral decubitus
lithotomy
other positions
beach chair
trendelenburg
reverse trendelenburg
sphinx
Patient monitoring
Check:
EKG/HR
BP
EtCO2
IV fluid administration
Urine output
Blood loss
Anesthetic cessation
prep for PACU/ICU
Gas/TIVA OFF
Reverse MR
adequate antinociceptic
postoperative phase
-patient transport to PACU or ICU
-evaluate pain management
PACU report
necessary Hx
surgery
fluids (blood loss, urine, fluids given)
drugs given
other pertinent info
general anesthesia
anesthetic where the anesthetis accomplished all 5 goals of anesthesia
general anesthesia stage 1
analgesia/induction
- period from initial administration of induction drugs to loss of consciousness
general anesthesia stage 2
excitement/delerium
- period from loss of consciousness
GA stage 2 physical signs
uncontrolled movements
pupillary dilation
irregular respiration
increased HR
GA stage 3
surgical anesthetic
Plane 1
from return of regular respirations to cessation of REM
Plane 2
from cessation of REM to paresis of intercostal muscles
Plane 3
from Intercostal paresis to complete paralysis of intercostals
Plane 4
from paralysis of intercostal muscles to diaphragmatic paralysisS
GA stage 4
overdose
Regional anesthesia
blocking pain and motor neuron firing in specific regions of the body with local anesthetic without exposing patient to risk of GA
Neuraxial anesthesia types
spinal
epidural
caudal
peripheral anesthesia
ultrasound guidance to identify nerves proximal to surgical site with infiltration of local anesthetic and other adjuncts to disrupt nerve transmission
epidural space
potential space between ligamentum flavum and dura
Dermatomes
spinal roots project to level of skin
C3-5
keep diaphragm alive
T1-4
cardiac accelerator fibers
T4
nipple line
T6
xiphoid process
T10
umbilicus
L1-5
bowel function
S1-3
innervation to perineum
Absolute contraindications to spinal/epidural
- infection at injection site
- lack of consent
- severe hypovolemia
- coagulopathy
- increased intracranial pressure (ICP)
Relative contraindications to spinal/epidural
- sepsis
- uncooperative patient
- preexisting neurological deficits (MS)
- stenotic valvular heart lesions (aortic stenosis)
- left ventricular outflow tract obstruction
- severe spinal deformity
peripheral nerve blocks
ultrasound guided infitration of local anesthetic around a nerve in order to block transmission of sensory nerve impulses
monitored anesthetic care (MAC)
pharmacologic sedation using opioids or hypnotic agent with monitoring during sedation
MAC risk
respiratory depression
UA obstruction
hypoventilation
hypoxemia
MAC failure reasons
patient intolerance
patient discomfort
patient complication (hemodynamic instability, hypoxemia)
procedural factors (bleeding, prolonged surgical time, procedure change)
Ramsey Sedation Scale 1
anxious
agitated
restless
RSS 2
cooperative
oriented
tranquil
RSS 3
drowsy but respons to commands
RSS 4
asleep
brisk response to stimul
RSS 5
asleep
sluggish response to stimulio
RSS 6
asleep
no response
