Regional Anesthesia Flashcards
How is CSF volume related to extent of spinal anesthesia?
CSF volume is inversely related to the height of the block
What are the indications for a stellate ganglion block?
CRPS 1 and 2 of the upper extremity
phantom limb pain of the upper extremity
refractory angina or VT
vascular insufficiency
What is the relationship of the stellate ganglion to the cervical vertebrae?
- located at C7
- can be blocked at the transverse process of C6 (tubercle of Chassiagnac)
What indicates a sucessful stellate ganlgion block? Other side effects?
** increased temperature of the upper extremity **
also: Horner’s syndrome (sympathetic palsy), hoarseness (recurrent laryngeal palsy, elevated hemidiphragm (phrenic nerve palsy)
What are the compliacations of a stellate ganlgion block?
intrathecal injection
vertebral artery injection
pneumothorax
hematoma
esophageal injury
Why is neuraxial anesthesia difficult in patients with ankylosing spondylitis?
osseous ligaments and smaller intervertebral space
What is the most frequent complication of an interscalene block?
Ipsilateral diaphragmatic paralysis
What forms the intercostobrachial nerve? What does it supply?
T2
sensory fibers to the medial upper arm
What is the order of blockade (sympathetic, sensory, motor) for upper extremity, lower extremity, and spinal blocks?
- upper extremity: sympathetic then motor then sensory
- lower extremity: sympathetic then sensory then motor
- spinal: sympathetic then sensory then motor
Which nerve is most often missed with an axillary nerve block? What does it supply?
musculocutaneous
lateral aspect of the forearm
How can a supplementary block of the musculocutaneous nerve be done?
Injection into the body of the choracobrachialis muscle
What is the nerve supply to the hand?
Where can the superficial cervical plexus be blocked?
midpoint of the posterior border of the sternocleidomastoid
Where can a deep cervical plexus block be performed?
transverse processes of C2-C4
What are the indications for cervical plexus block?
carotid endarterectomy
superficial neck surgery
Where is the celiac plexus located?
L1
What sensory information is transmitted through the celiac plexus?
visceral pain from the mid-stomach to the mid-transverse colon
What are the most common side effects of a celiac plexus block?
- orthostatic hypotension (splanchnic vasodilatation)
- diarrhea (splanchnic vasodilatation)
- paraplegia (injury to the artery of Adamkiewicz)
How does epidural anesthesia affect bowel function?
increases gut motility and decreases the chance of ileus
How is a subdural block differentiated from a subarachnoid block?
- slower onset
- extensive sensory block with minimal motor block
- less hypotension (but more than epidural)
What indicates complete resolution of a spinal block?
ability to urinate
Which fascial planes are traversed during a femoral nerve block?
fascia lata then fascia iliaca
What factors determine degree of hypothermia during spinal anesthesia?
- height of block
- patient age
What are the indications for a sphenopalatine ganglion block?
analgesia following endoscopic sinus surgery
What is the dermatome map?
When can prophylactic Lovenox be resumed after removal of an epidural catheter?
4 hours after
What is the upper limit of PTT to administer neuraxial anesthesia according to ASRA guidelines?
1.5 x normal (40)
How long should Plavix, dabigatran, Eliquis, Xarelto, and eptipibatide be held prior to neuraxial anesthesia?
Plavix: 5 days
Eliquis and Xarelto: 3-5 day
dabigatran: 3 days
eptifibatide: 8 hours
How high will a neuraxial block typically rise with hyperbaric local ansethetic in a supine patient?
about T6
(due to normal kyphosis of the thoracic spine)
Which patient factors are assoiated with high spinal block due to decreased CSF volume?
pregnancy
ascites
severe kyphoscoliosis
advanced age
When are the two peaks of respiratory depression following intrathecal morphine administration? Peak analgesia?
peak respiratory depression: after injection and 6 hours later
peak analgesia: 6-12 hours after injection
Is pruritis worse with neuraxial or IV opioid administration?
neuraxial administration
Which epidural local anesthetic may (unlikely) interfere with the efficacy of epidural opioids?
chloroprocaine
What areas are most commonly spared by an interscalene block?
ulnar nerve (C8-T1)
proximal cutaneous shoulder (covered by superficial cervical plexus block)
Which left sided upper extremity block has the highest risk of chylothorax?
infraclavicular
Which nerves mediate wrist extension? Flexion? Pinch?
Extension: raidal
Flexion: median
Pinch: ulnar
What are the max doses of commonly used local anesthetics for regional anesthesia?
bupivacaine: 2.5 mg/kg (3 mg/kg w/ epi)
ropivacaine: 2-3 mg/kg
mepivacaine: 5 mg/kg (7 mg/kg w/ epi)
lidocaine: 4.5 mg/kg (7 mg/kg w/ epi)
Branches of which nerve predominantly carry sensation to the plantar surface of the foot? Dorsal surface?
plantar surface: tibial nerve
dorsal surface: common peroneal nerve
What innervates the web space between the great and second toes?
deep peroneal nerve
