14 - Anesthesiology principles & pain management Flashcards
What are the 4 categories of drugs used in anesthesiology?
inhalators (maintenance) hypotonic IV (induction) analgesia muscle relaxation (paralytica)
The goal of inhalator drug to to provide fast __ which is non __ and clears out quickly.
induction
toxic
Blood-gas solubility coefficient is a measure of the drug’s __ to the __.
uptake
blood stream
Less soluble inhalator drugs (__/__) lead to faster __ and __.
N2O/desflurane
induction
clearance
More soluble drugs inhalator (__) clear more __.
halothane
slowly
MAC measures the concentration needed to prevent __ due to __ in 50% of patients.
movement
surgical incision
The higher the MAC, the __ potent the drug is.
less
Examples for inhalator MAC:
Halothane-
Desflurane-
N2O-
0.75%
6%
104%
Pungency of an inhalator may lead to __.
respiratory irritant
Mention 2 low pungency drugs used for induction:
halothane
desflurane
N2O is used for fast __ when combining with another inhalator.
induction
What are the advantages of N2O?
minimal effect on respiratory/hemodynamic status
What are the disadvantages of N2O? 2
Not good for maintenance
increased ventilation pressure/volume
What are the C/I for N2O? 4
pneumothorax
SBO
auricle surgery
retina surgery
What is the most common inhalator used for induction?
isoflurane
Isoflurane is not used for __.
induction
Isoflurane is better than ___ since it decrease less __, and has __.
halothane
CO
minimal metabolism
Isoflurane is less sensitive to the __ effect of ___.
arrhythmogenic
catecholamines
What are the disadvantages of isoflurane? 3
tachycardia (requires monitoring)
increases ICP in high dosage
high pungency
Sevoflurane is an effective __ inhalator.
induction
What are the advantages of sevoflurane? 4
low solubility
less pungency
no CV effect
Which patients are likely to be inducted with sevoflurane? 4
children
bronchospasm
outpatients surgery
mask induction (for difficult airway)
Desflurane is not used for __.
induction
What are the advantages for desflurane: 2
fast effect
fast clearance
What are the disadvantages of desflurane? 3
high potency
tachycardia
HTN
What are the main hypotonic drugs used for induction? 4
midazolam (dormicum)
ketamine
etomidate
propofol
Dormicum is a __ acting __ with __ T1/2.
fast
benzodiazepine
short
Midazolam leads to __ and anti __ effect. It does not have __ effect.
amnesia
anxiety
analgesic
Since dormicum has minimal ___ effect, it is good for __ surgery.
cardiac
heart surgeries
Midazolam can cause __.
hypotension
Ketamine has a strong __ effect.
analgesic
Ketamine does not cause __ decrease, but if there is symptomatic tonus (__), it may lead to __.
hemodynamic
hemorrhagic shock
hypotension
In patients with maximal symptomatic tonus (__/__ shock) ketamine dosage should be __ by __% of normal dosage.
septic/hemorrhagic
decreased
20
Ketamine is the drug of choice for patients with __ since it does not decrease __.
hypovolemia
BP
Ketamine is the drug of choice for patients with __, since it causes __.
asthma
bronchodilation
What are the disadvantages of ketamine? 5
increases symptomatic tonus (increased ICP) tachycardia HTN bronchodilation dissociative effect/delirium
Ketamine is not recommended for patients with __ disease, as it can cause heart __.
coronary
ischemia
What are the C/I for ketamine? 3
abdominal surgery
coronary disease
increased ICP
Etomidate is a __ agonist with __ effect and no __ effect.
GABA
fast
analgesic
What are the indications for etomidate?
trauma
hypovolemia (2nd line)
coronary disease (GS)
Why etomidate is good for trauma?
has minimal CV effect
What are the disadvantages of etomidate?
local pain
myoclonus
decreased ICP
adrenal inhibitor
Propofol is a __ agonist with __ effect and no __ effect.
GABA
fast
analgesic
Propofol is a good __ drug.
maintenance
What are the indications for propofol? 3
short sedations (endoscopy) asthma (causes bronchodilation) no NV (nausea/vomiting)
What are the disadvantages of propofol?
local pain (we add lidocaine) fast hypotension due to vasodilation
Which patients would not be recommended propofol?
hypovolemic
coronary disease
Asthma patients should be inducted with: 2
ketamine
propofol
Renal failure patients should be inducted with: 3
ketamine
propofol
etomidate
Cardiac patients should be inducted with: 2
midazolam (dormicum)
etomidate
Remember that __ is the only induction drug that increase ICP, while the rest decrease it.
ketamine
What are the advantages of using analgesic drugs? 4
reducing MAC for inhalators
mask the tachycardia/HTN caused by ventilation
allow easier waking
can be used as anesthetic if used in X10-20
What are the disadvantages of using analgesic drugs? 3
hypoventilation
hypnosis
amnesia
What are the 4 types of analgesic drugs?
fentanyl
morphine
pethidine
tramadol
Fentanyl is a very __ drug with __ effect, lasting for - minutes.
potent
fast
20-30
Fentanyl is used as __ analgesic.
maintenance
What is the antidote for fentanyl?
naloxone
Morphine is used more for __ operative pain.
post
What is the antidote for morphine?
naloxone
Morphine starts effecting within __, and last for - hours.
minutes
3-4
Tramadol has a strong __ effect, and should be administrate in a __ together with /. Used mostly for __ pain.
emetic
slow drip
zofran / pramin
postoperative
What are the two groups of muscle relaxing drugs?
depolarizing (non-competative) non depolarizing (competitive)
__ is a depolarizing drug.
succinylcholine
Succinylcholine is indicated for __ intubation. The effect lasts for _ minutes.
fast
5
Before using depolarizing drugs, make sure the patient can be ventilated with a __, incase the __ fails.
mask
intubation
Which patients are more difficult to ventilate with a mask? 2
obese jaw malformation (micrognathia)
What are the disadvantages of succinylcholine?
bradycardia (more in children)
hyperkalemia (more in burn/RF/trauma/paraplegia)
malignant hyperthermia (more in myopathy/family history/children)
muscular pain
What are the two competitive neuromuscular blockers drugs commonly used?
rocuronium
vecuronium
What are the indications for non depolarizing drugs?
easy intubation
maintenance
What are the disadvantages of non depolarizing drugs?
dose adjustment in RF
can mask lack of analgesia (paralyzed but feel pain)
myopathy and neuropathy
What is the antidote of rocuronium? what should it given with?
neostigmine
atropine
Why do we give atropine together with neostigmine?
to avoid arrhythmia/asystole
If using rocuronium, at the end of the surgery we must give ___ (__).
antidote
neostigmine
What is TOF (train of four)?
quantitative measurement determining the depth of anesthesia and level of neuromuscular paralysis
If there are 4 TOF twitches the level of block is __ and only then it is safe to __.
0
extubating
Describe what percentage of receptors are blocked at each twitch disappearance: loosing the 4th -\_\_% loosing the 3th -\_\_% loosing the 2th -\_\_% loosing the 1th -\_\_%
75%
80%
90%
100%
What is the TOF ratio?
the ratio between the intensity of the 4th twitch and the 1st
At what TOF ratio can you safely extubate?
> 0.9
What is percentage of oxygen saturation do we ventilate?
30-35%
When should we use arterial line to monitor BP during surgery? 5
- predicted hypotension/extreme changes during surgery
- surgeries with hemodynamic effect (hepatic/trauma)
- a need for frequent ABG
*
Where would you insert an arterial line? 2
radial artery
axillar artery
Which surgeries may have high hemodynamic effect on the patient- requiring arterial line BP monitoring? 6
hepatic surgeries (e.g. Whipple) trauma/MOF cardiac morbidity pheochromocytoma carotid surgery difficult external monitoring (obesity/burn)
Which patients are most sensitive to temperature loss during surgery? 2
children
burn patients
Which disorders may occur due to hypothermia? 5
coagulopathy SSI (surgical site infection) ischemia induced by stress arrhythmia apnea
What does end tidal CO2 measure?
the maximum concentration of CO2 in the airway at the end of expiration
Using EtCO2 is the GS for locating where the __ is and as a measurement of the heart __ and __.
tracheal intubation
perfusion
production
What is the normal EtCO2? - mHg
35-45
Increased EtCO2 (hypoventilation) may suggest increased:
BP
metabolic rate
hyperthermia (malignant hyperthermia)
Increased EtCO2 (hypoventilation) may suggest decreased:
respiratory rate
tidal volume
Increased EtCO2 (hypoventilation) may also suggest: 2
thyroid storm
sepsis
Decreased EtCO2 (hyperventilation) may suggest increased: 2
respiratory rate
tidal volume
Decreased EtCO2 (hyperventilation) may suggest decreased: 3
BP
tidal volume
metabolic rate
Decreased EtCO2 (hyperventilation) may also suggest: 3
hypothermia
bronchospasm
massive PE
How can we get a general sense of intravascular volume and renal perfusion during surgery?
urine catheter
What do we use to evaluate the filling pressure of the right heart after fluid administration?
CVP
Where would a CVP be inserted? where should it be placed?
above diaphragm main veins (subclavian, brachial, jugular veins)
entrance of the SVC to the right atrium
What are the possible risks of CVP? 5
pneumothorax AV fistula air emboli arrhythmia thrombosis/infection
What are the normal CVP levels? - mmHg
2-6
How can you evaluate the filling pressure in the left atrium?
PAC (pulmonary artery catheter)
Where would a PAC be inserted? where should it be placed?
neck veins
pulmonary artery
What else can be evaluated using PAC?
pulmonary pressure
cardiac production
What are the possible risks of PAC? 5
arrhythmia (VT...) AV block PE valvular damage bleeding
__ is a complete C/I for PAC
LBBB
What are the normal levels of PCWP (Pulmonary wedge pressure) measured by PAC?
8-12 mmHg
ASA classification= __
standards for basic anesthetic monitoring
ASA standard I= anesthetist should be present during __ and follow the __ status based on dynamic changes of the patient.
anesthesia
hemodynamic
ASA standard II- continues monitoring of 4 during all stages of the anesthesia.
ventilation
oxygenic
circulation
temperature
ASA standard II requires __ analyzer, pulse __, monitoring __, signs monitoring every _ minutes, __ measurement and adapting the room accordingly.
oxygen oximeter EtCO2 5 temperature
Name 5 reasons for instability during surgery:
MI PE pneumothorax anaphylaxis malignant hyperthermia
How would you manage a patient suffering from MI during surgery?
hemodynamic stable and no perfusion disorder- continue
instable patient- cease surgery and evaluate
_% of patients going through hip surgery may suffer from __.
2
PE
What are the clinical presentation of a perioperative PE? 3
tachycardia
hypotension
hemodynamic collapse
How do you diagnose perioperative PE?
TEE
How do you treat perioperative unstable PE?
cease the treatment and give cardiac support/thrombolytic/embolectomy
Pneumothorax is a common __ complication. Clinical signs include: 4
laparoscopy
desaturation
hypercarbia
hypotension
How do you manage an unstable perioperative pneumothorax?
cease surgery -> stop inflating the abdomen ->pulmonary tube
What are the common causes for perioperative anaphylaxis? 4
latex
relaxants (rocuronium, vecuronium, succinylcholine)
Abx
blood products
How do you manage an unstable perioperative anaphylaxis? 4
adrenaline
H2 blockers
Hydrocortisone
fluids
Malignant hyperthermia is usually with a __ predisposition (__/__)
genetic
Duchenne muscular dystrophy
other myopathies
What is the clinical presentation of malignant hyperthermia? 8
increase sympathetic activity rapid hyperthermia rigidity metabolic/respiratory acidosis hypotension arrhythmia seizures CPK/myoglobinuria
What is the treatment for malignant hyperthermia? 6
stop all suspected anesthetic dantrolene cooling sodium bicarbonate (for acidosis) treating hyperkalemia treat arrhythmia
When performing preoperative evaluation ask if in the past there was a delayed waking up after anesthesia as a marker for __ deficiency.
pseudocholine esterase
If a patients has a pseudocholine esterase deficiency- avoid ___.
succinylcholine
Mallampati score relates to the distance between the __ and __.
tongue
pharynx
Mallampati class 1: ___
soft palate + uvula + anterior/posterior pillars
Mallampati class 2: ___
soft palate +uvula
Mallampati class 3: ___
soft palate + uvula base
Mallampati class 4: ___
soft palate is invisible
How wide should the mouth opening and thyromental distance be?
6-8 cm (3-4 fingers)
What are the 4 criteria in Mallampati classification?
class
mouth opening
thyromental distance
neck extension
What are the death percentage for each ASA score? 1- 2- 3- 4- 5- 6-
1- 0.06-0.08% 2- 0.27%-0.4% 3- 1.8-4.3% 4- 7.8-23% 5- 9.4-51% 6- 100%
ASA 1= ___ patient
healthy
ASA 2= mild __ disease w/o __ limitation (eg. __).
systemic
functioning
balanced HTN/DM
ASA 3= ___ systemic disease with functioning ___ (eg.__).
severe
limitation
COPD/MI history
ASA 4= Severe __ disease with a __ life threat (eg. __).
systemic
constant
unstable angina/HF
ASA 5= Expected __ if surgery will not be performed in the next __ hours (e.g. __).
death
24
aortic aneurysm/brain bleeding/MOF
ASA 6= ___ before __.
brain death
organ saving
When assessing a patient cardiovascular status pre-op check if there was a previous __. If the answer is yes- consult a cardiologist, if not- continue.
ACS
MACE (major adverse cardiac events) >__% requires further investigation.
1
METs (metabolic equivalents) > 10- ___
no further investigations, continue to surgery
METs (metabolic equivalents) 4-10- ___
no further investigations, continue to surgery
METs (metabolic equivalents) <4- ___
further investigation is needed (exertional test/heart mapping)- if not in order -> PCI
If PCI was performed, surgery is done __ days after.
14
If PCI + BMS was performed, surgery is done __ days after.
30
If DES was performed, surgery is done __ months after.
6-12
Patients with ICD require an ___ to be present in the OR.
external defibrillator
What does the pulmonary pre-op check involve? 5
history physical CXr ABG respiratory function
__, __, and __ are not significant respiratory risk factors.
smoking
obesity
mild asthma
Patients with OSA are in increased risk for prolonged __.
dyspnea
In the case of active COPD/asthma consider to __ the surgery until respiratory __.
postpone
stabilization
Patients going through dialysis should be operated - hours after their last treatment.
18-48
Diabetic patients should __ there pump insulin treatment, keeping them in the __ values.
continue
basal
At the morning of the surgery, DM patients should use a __ dose of __-__ range insulin. Stop other related drugs (__)
decreased
medium-long
metformin
Pre-op fasting involves __ and __ for _ hours before.
_ hours before the surgery, patients should avoid __ completely.
Breast milk-__ hours
cow mike- __ hours
formula- __hours
solids clear fluids (water) 2 drinking 2 4 6
Anticoagulation should be __ and bridged with __.
withheld
clexane
COPD patients should be treated with ___ before surgery.
bronchodilators
What is recommended for patients with risk for aspiration before starting the surgery? 2
pramin
PPI (a night before surgery)
Anti anxiety, usually __ can be used. Avoid in __, __ and __.
benzodiazepine
pulmonary disease/OSA/elders
What are the 3 anesthesia techniques?
local
regional
general
What are the indications for RSI (rapid sequence intubation)? 3
full stomach (emergency unfasted surgery) Increased abdominal content (pregnancy/abdominal mass/ascites) delayed gastric emptying (Bowel obstruction/opioid use/DM/pregnancy)
When performing RSI:
1) prepare the tools
2) preoxygenate (__)
3) give both __ and __ simultaneously
4) perform __ maneuver
5) __
6) __
100% oxygen for 3 minutes hypotonic (propofol) + muscle relaxant (rocuronium) Sellick intubate nasogastric tube
Local anesthesia mechanism is based on __ channel blockage in the neuro fibers
Na
In local anesthesia, the lower the pKa, the __ the effect is, the more hydrophobic the __ potent, the better it can bind to protein the __ the effect lasts for.
faster
more
longer
What are the two groups of local anesthesia? 2
aminoamide (lidocaine) amino ester (chloroprocaine)
What are the neurotoxic signs of local anesthesia? 6
mouth tingling tinnitus visual impairment disorientation slurred speech seizures (treat with diazepam/thiopental if it doesn't pass)
What other clinical signs can be seen in local anesthesia toxicity? 2
arrhythmia (QRS prolongation)
metallic taste
How can you prevent local anesthesia toxicity? 2
pull before push
add epinephrine
The further away the regional anesthesia is from a __ blood vessel, the __ the absorption and __ effect.
large
slower
longer
What late complication can be caused by regional anesthesia? 5
headache back pain urinary retention neurological complications SSI/meningitis
What are the C/I for regional anesthesia? 5
local infection at the site
coagulation disorder/active anticoagulant
sepsis/bacteremia
hypovolemic shock
advanced neurological disease/elevated ICP
What are the indications for spinal anesthesia? 4
urologic surgery
abdominal surgery
anus surgery
lower limb surgery
Spinal anesthesia effect is __, more __, and leads to less __ pain than epidural anesthesia.
faster
efficient
back
Spinal anesthesia block both __ and __ sensation under the level of the block.
motor
sensor
What are the advantages of spinal anesthesia? 3
preventing airway/general anesthesia complications
the patients is awake (good for TURP surgery)
less delirium in elders
What are the disadvantages of spinal anesthesia? 7
post-dural headache (more in young, women, large needle)
hypotension/bradycardia
neuropathy
back pain
urine retention
epidural hematoma
respiratory depression/arrhythmia if spreads cephalic
What are the indication for epidural anesthesia?
abdominal surgery
chest surgery
lower limb surgery
In epidural anesthesia the needle is inserted into the __ space between the ligamentum __ and the __ matter.
epidural
flavum
dura
What are the advantages of epidural anesthesia? 4
better respiratory functions
better pain control
less pneumonia (same mortality)
less ileus
What are the disadvantages of epidural anesthesia? 3
epidural/spinal hematoma epidural abscess (requires MRI)
What are the risk factors for epidural hematoma? 2
coagulation disorder/anticoagulation
prophylactic clexane post surgery
What are the clinical presentations of spinal hematoma?
back pain
motor/sensory disorder of the lower limbs
urinating/defecation disorder
Stop clexane __ hours before epidural catheter insertion. Avoid clexane _ hours after the insertion.
24
6
Stop clexane __ hours after epidural catheter clexane removal. Resume clexane __ after removal.
12
2
In the first 24 hours post-op the patient should regain time/place orientation. In case of delirium/tough awakening - treat with __.
Haldol
What are the criteria for extubating? 3
independent breathing (4-6 cc/kg TV or 30>RR>7 ) awake/responsive/protective reflexes/TOF ratio>0.9 no hypothermia/acidosis/electrolyte disorder
In case of post anesthetic laryngospasm treat with:
positive pressure oxygen (__) ->
___
___
CPAP
succinylcholine
ventilation
In case of post anesthetic vocal cord edema treat with:
__->
inhalator and IV ___ + inhalator __
oxygen
steroids
epinephrine
PONV=__
post operative nausea & vomiting
PONV is caused by central damage to the __. Treatment includes __ (careful from long QT) and if administrated with __ + __ can cause bradyarrhythmia.
brainstem
Droperidol
Ondansetron
Metoclopramide
Using __ for maintenance reduces the frequency of PONV.
propofol
30 minutes post op the desired body temp should be > __.
36
hypothermia increases the risk for:
MI in CAD patients (due to shivers->oxygen demand)
drug metabolism
coagulation disorders (death triad)
SSI
Chronic pain lasts > __ beyond the expected healing time from surgery.
a month
Chronic pain is describes as: 3
burning
stinging
shock like
What are the risk factors for chronic pain? 5
- surgery type (neck/mastectomy/thoracotomy/hernia/amputation)
- SSI
- nerve pain during the surgery
- DM
- tumor involvement (nerve entrapment)