Not General Anesthesia Flashcards
T or F: According to the asa, MAC anesthesia is held to the same standards as general anesthetics?
TRUE
T or F: MAC cases do not require the same set up as for general anesthesia?
FALSE
What are the ASA guidelines for MAC cases for oxygenation:
100% O2 inspired gas
never use N2O b/c of no scavenging
must have pulse ox
What are the ASA guidelines for MAC cases for ventilation:
must use capnography
What are the ASA guidelines for MAC cases for circulation:
must monitor ECG and HR
must measure BP (NIBP, IBP)
should auscultate heart sounds
should palpate pulse
Define spinal neuraxial anesthesia:
injecting local anesthesia into the CSF within the subarachnoid space
Define epidural neuraxial anesthesia:
injecting local anesthesia into the space that lies within the vertebral canal but superficial to the dural sac
What are 3 neuraxial contraindications?
Absolute
Relative
Controversial
What are examples of absolute contraindications?
injection site infection patient refusal hypovolemia increased intracranial pressure aortic/mitral stenosis
What are examples of relative contraindications?
sepsis
uncooperative patient
neurologic deficit
spinal deformity
What are examples of controversial contraindications?
prior back surgery
inability of the patient to communicate
surgeon preference
complicated surgery
What drug must be stopped before neuraxial anesthesia can be performed?
Coumadin
What drug needs to have been taken for at least 7 days for neuraxial anesthesia?
Plavix
The illiac crest crosses the spinal chord at what point?
L4
This is the principal landmark for spinal anesthesia
The inferior tip of the scapula is located at what point on spinal chord?
T7
This is the principal landmark for thoracic epidural
What is another name for where the illiac crest crosses spinal chord?
Tuffiers line
The spinal chord ends at what point in an adult ?
L1-L2
The order of ligaments from skin to vertebrae:
Supraspinous ligament Infraspinous ligament Ligamentum flavum Dura Arachnoid membrane
The spinal chord ends at what point in a child?
L3-L4
What is the dermatome for belly button?
T10
What is the dermatome for nipple?
T4
What are indications for epidurals?
Primary anesthetic for belly or lower extremity
supplement to GA
postoperative pain control
can be continuous
What are indications for spinals?
Lower abdomen/perineum/lower extremities
One time shot
much faster
When doing a midline insertion, the needle:
comes straight on along same line as spinous process
When doing a paramedian insertion, the needle:
comes in at an angle
The block of the posterior nerve roots interrupts ?
somatic and visceral sensations
The block of the anterior nerve roots prevents?
motor and autonomic outflow
Somatic blockades are used for?
-Interruption of painful stimuli
-abolish skeletal muscle tone
is a differential blockade:
1) sympathetic: works 4 dermatomes away from block
2) sensory : work 2 dermatomes away from block
3) motor: works closest to injection site
Cardiovascular manifestations following a blockade include:
Decrease BP
decrease HR
decrease contractility
PROFOUND bradycardia when blocking cardiac accelerators located T1-T4
What pulmonary consideration must be accounted for when doing blocks?
Proximity to phrenic nerve from C3-C5 (diaphragm)
What size needle to you use when doing epidurals?
17-20 gauge
What size needle do you use when doing spinals?
22-24 gauge
What is one way to minimize the cardiovascular effects of blocks?
Make sure at least 1 L of fluid has been given prior to starting procedure
All about epidurals:
greater control over intensity of sensory block
motor block achieved by local concentration
provides means of long term drug administration
Disadvantages of epidurals:
Covers larger area, but far less intense
slower onset time (10-20 min)
block is less dense
What is the test dose give before epidurals and why do you give it?
3 ml of 1.5% lidocaine with epi
Makes sure you are in epidural space and not through dura into CSF: if in CSF legs will go numb
Epi in test dose makes sure your not in blood vessel : epi would make HR go up
When placing epidurals:
Volume and concentration much greater than spinal
1-2ml of local per segment
Drug must be preservative free
Advantages of spinal anesthesia:
Less time to perform
less local required
more intense sensory and motor block
needle placement confirmed by CSF dripping out of needle (instead of waiting on test dose with epidural)
What is baricity?
How heavy(density) is the drug compared to the CSF fluid
What is the CSF specific gravity?
1.003 - 1.008
What is the name if a drug is greater density than CSF (heavier) ?
What will it do in the CSF Fluid?
Hyperbaric
Sinks
What is the name if a drug is lesser density than CSF (lighter) ?
What will it do in the CSF Fluid?
Hypobaric
Floats
Adding glucose to the drug will do what?
makes drug heavier or more hyperbaric
Adding sterile water to the drug will do what?
makes drug lighter or more hypobaric
What is the most common side effect of neuraxial anesthesia?
Postdural puncture headache
If you were to use a drug that contained preservatives, what would happen?
Preservatives cause inflammation of the chord
Postduraal headaches are caused by what?
CSF leak that causes ICP to decrease
What are the remedies of postdural puncture headache?
Laying down turning off lights/being in the dark take NSAID's increase fluid intake get caffeine Epidural blood patch
What effect does caffeine do to the body?
stimulates an increase in CSF fluid production
What is an epidural blood patch?
Where the patients own blood is used to form a patch in the epidural space where the needle punctured the dura
What is the onset and duration of a post dural puncture headache?
Onset: 12 hours to 3 days later
Duration: can last several days
What is the most common regional anesthesia technique in pediatrics?
caudal anesthesia
Locations for a brachial plexus nerve block?
Interscalene
supraclavicular
infraclavicular
axillary
optimal for procedures of shoulder, arm and forearm
Most intense at C5-C7
Least intense at C8-T1
interscalene block
All about supraclavicular block:
anesthesia of entire arm including hand
high incidence of pneumothroax
High incidence of phrenic nerve block
All about infraclavicular block:
anesthesia of hand, forearm, elbow and upper arm
high incidence of pneumothorax
All about axillary block:
most common approach to brachial plexus
procedures distal to elbow
Femoral nerve block:
block of anterior thigh, knee, medial foot
used in combo with other blocks
post op pain for knee surgery
When visualizing, use NAVY (nerve, artery, vein, y made by legs)
Obturator nerve block:
anesthesia to medial thigh and muscle relaxation of adductor hip muscles
Part of 3 in 1 block with femoral and lateral femoral cutaneous
Sciatic nerve block:
L4-L5 and S1-S3 nerve roots
sensory block to posterior hip and knee and lower extremity
motor block to hamstrings and lower muscles
Lumbar plexus (psoas) block:
used for total hip and total knee analgesia
Popliteal block:
used for foot and ankle surgery
Saphenous nerve block:
used for sensory innervation along medial aspect of lower leg
