Regional Flashcards
Order of differential neuroaxial blockade from least to most dense?
SANS < temp & pinprick < pain (sensory) < motor
BENIGN radicular irritation associated with spinal lidocaine, obesity, lithotomy position, and ambulatory surgery with early ambulation. No sensory or motor changes; only back pain with radiation butt, thighs, hips, and calves. Symptoms last 1-3 days and resolve spontaneously.
TNS
Only scenario in which lovenox can be restarted WITH neuroaxial catheter in place
ONCE daily prophylactic dosing; Can restart lovenox after 6-8 hours
How long to wait after stopping Lovenox for neuroaxial puncture?
12 hours with dosing < 10,000U
24 hours with dosing > 10,000
Do not place neuroaxial if PTT = ? or INR = ?
PTT > 40
INR > 1.5
How long to wait before neuroaxial puncture after stopping Tirofiban/Eptifibatide?
8 hours
“Elliptical for 8 hours”
How long to wait before neuroaxial puncture after stopping Dalteparin?
12 hours if prophylactic dose
24 hours if full treatment dose
How long to wait before neuroaxial puncture after stopping Fondaparinux?
2 days if prophylactic dose
3 days if full treatment dose
“Fondue party in 2-3 days”
How long to wait before neuroaxial puncture after stopping argatroban, bivalirudin, or lepirudin?
PTT < 40
How long to wait before neuroaxial puncture after stopping Abciximab?
2 days
How long to wait before neuroaxial puncture after stopping Dabigatran?
3 days if renal function intact and no other risk factors for bleeding (Cr clearance > 80 mL/min)
otherwise, 5 days
How long to wait before neuroaxial puncture after stopping clopidogrel?
7 days
How long to wait before neuroaxial puncture after stopping Alteplase?
10 days
How long to wait before neuroaxial puncture after stopping ticlopidine?
14 days
Normal kyphosis limits spinals to what level?
T6
Decreased CSF volume in following states?
pregnancy (2/2 epidural vein engorgement and progesterone), ascites, advanced age, severe kyphoscoliosis
*NOT OBESITY
Opioids that cross dura quickly therefore less epidural spread (narrow band of analgesia) and short duration
lipophilic opioids like fentanyl and sufentanil
Opioids that cross dura slowly therefore more time to travel rostrally and longer duration of action
lipophobic opioids like morphine
Purpose of epinephrine in neuroaxial blocks?
Prolongs duration
Adds density to spinals
No added density to epidural
Attenuates neuroaxial opioids except butorphanol?
Chlorprocaine
Artery located (inferiorly) in line with interscalene roots/trunks in ultrasound image?
vertebral artery
Vessels located medial to interscalene roots/trunks (and in line with superficial cervical plexus) on ultrasound image?
Internal Jugular and carotid artery between anterior scalene muscle and sternocleidomastoid muscle
less risk of phrenic nerve block with interscalene or supraclavicular?
supraclavicular but remains very common
phrenic nerve is blocked 100% of the time with interscalene block
less risk of pneumothorax with interscalene or supraclavicular block?
interscalene
landmarks of femoral nerve?
inguinal ligament superior
adductor longus medial
sartorius lateral
oculocardiac reflex mediated by?
V1 via ciliary ganglion IN
X (vagus) OUT
artery located in ultrasound image of supraclavicular trunks/divisions directly above 1st rib?
subclavian artery
Bezold-Jarisch Reflex
PANS reflex!!
Bradycardia and decreased contractility mediated by stretch R’s in left ventricle in response to acute drop in preload (thought to allow additional filling time)
nerves covered by TAP block
subcostal, intercostal, iliohypogastric, and ilioinguinal
T9-L1
interscalene block for shoulder surgery also covers which other nerve via spillover?
supraclavicular nerve of superficial cervical plexus
Maximum lidocaine dose plain versus lidocaine with epinephrine?
5 mg/kg
7 mg/kg
Maximum bupivicaine dose plain vs. bupivicaine with epinephrine?
2.5 mg/kg
3 mg/kg
maximum dose of ropivicaine?
3 mg/kg
Maximum dose of chlorprocaine?
12 mg/kg
Local anesthetic absorption from highest to lowest…think ICPEBaLLS
IV > tracheal
intercostal > caudal > paracervical > epidural > brachial plexus > lower legs > subcutaneous
Dose for 20% lipid emulsion if treating LAST?
2.5 mL/kg over 1 minute
followed by
0.25 mL/kg/min infusion (may incr to 0.5 mL/kg/min)
ACLS dose of epinephrine in LAST
decreased to < 1 mcg/kg
Avoid which drugs in LAST?
beta blockers, calcium ch blockers, vasopressin, and local anesthetics
DOC for ventricular arrhythmias?
amiodarone
DOC for ventricular arrhythmias in LAST?
amiodarone
Sensory innervation to nasal mucosa, hard palate and lacrimal glands?
Sphenopalatine ganglion (V2 - maxillary branch of trigeminal nerve)
Sensation to medial forearm?
medial antebrachial cutaneous nerve
sensation to dorsal hand?
radial nerve
nerve that allows wrist flexion?
medial nerve
nerve that allows wrist extension?
radial nerve
sensation to palm of hand?
Median (first 3.5 fingers) and ulnar nerve (last 1.5 fingers)
nerve that allows hand closure and thumb adduction
ulnar nerve
Which orbital block additionally blocks the levator palpabrae?
peribulbar block
nerve that allows eversion and dorsiflexion?
common peroneal nerve
L5-S1
Nerve that allows plantar flexion and inversion?
Tibial nerve
What regional anesthesia is necessary for lateral wall bladder surgery?
spinal anesthesia
plus obturator nerve to prevent adductor muscle jerk reflex
-OR- GA plus paralysis
The 3-in-1 block often misses?
the obturator nerve
where to inject for lateral femoral cutaneous nerve block?
2-2.5 cm medial and inferior to ASIS. Distribute LA above and below fascia lata
where to inject for obturator nerve block?
sensory portion is between adductor longus muscle and adductor brevis muscle. this is the anterior branch of the nerve.
muscles superficial to deep: ALABAMa - adductor longus, adductor brevis, adductor magnus
lumbar plexus block also known as psoas compartment block spares which nerve?
Sciatic nerve
Reliably blocks lateral femoral cutaneous, femoral and obturator nerves (VENTRAL RAMI T12-L4)
Which blocks to render eye immobile?
Retrobulbuar/peribulbar plus facial nerve to target orbiculares oculi muscle
Non-cutting spinal needles?
Whitacre or Sprotte
Interscalene blocks the brachial plexus where?
At nerve roots and trunks
Supraclavicular blocks the brachial plexus where?
trunks and origin of divisions
infraclavicular blocks the brachial plexus where?
Cords
Axillary blocks the brachial plexus where?
Nerve BRANCHES
How does adding bicarb to lidocaine help?
increases pH so decreased pain on injection
increases the UNionized portion of the local anesthetic which speeds time of onset
**Don’t mix bicarb with ropi or levobupivicaine because much less soluble so precipitation will form
Allergy to esters likely due to what? (procaine, benzocaine, tetracaine)
Hypersensitivity to PABA (a metabolite of esters)
Allergy to amides due to?
methylparaben (which is metabolized to PABA)
**Allergy to amides rarer than esters
Which is more common? allergy to amides or esters?
ESTERS
landmarks to infragluteal sciatic nerve block
ischial tuberosity, greater trochanter, and sciatic groove
sciatic groove is between femur and long head of biceps femoris
Innervation of lateral skin on nose, cheek and upper lip?
infraorbital nerve (derived from maxillary branch of trigeminal nerve v2)
where to inject for TAP block?
between internal oblique and transverses abdominus
entrapment of lateral femoral cutaneous nerve following prolonged labor is called? (causes anterolateral thigh burning pain)
meralgia parasthetica
redirect needle in which direction during interscalene block if there is a diaphragmatic response (coughing, hiccups or gasping)?
posteriorly
Redirect needle in which direction during femoral nerve block if there is only a sartorius twitch?
lateral and deeper - endpoint of femoral nerve stimulation should be patellar twitch +/- sartorius twitch
Nerves that must be blocked for awake intubation?
(1) glossopharyngeal n. via soaked pledget @ the base of palatoglossal fold
(2) RLN via transtracheal injection
(3) SLN by injection at horn of the hyoid or pledget in the piriform sinus
(4) mandibular br. of trigeminal nerve via topical anesthesia
The musculocutaneous nerve provides sensory innervation to?
lateral forearm
Radicular symptoms associated with spinal lidocaine, obesity, lithotomy position, and ambulatory surgery with early ambulation
TNS
Ultrasound image of medial forearm - identify labels
A: flexor carpi ulnaris tendon and muscle
B: ulnar nerve
C: ulnar artery
Coadministering liposomal bupivicaine with ____ will cause a disruption in the drug delivery system?
Any local anesthetics other than plain bupivicaine; delay administration at least 20 minutes following lidocaine administration in the same area
also WET chlorhexadine or povidone iodine solutions will disrupt the drug delivery system
Important landmark for blocking LFCN?
ASIS - 2.5 centimeters medial and inferior to ASIS – inject above and below fascia lata
Risk factors for cauda equina syndrome?
Small bore spinal catheters, spinal stenosis, patient positioning due to maldistribution of local anesthetic.
Methylene blue is beneficial in which pathophysiology other than methemoglobinemia?
Vasoplegia syndrome (profoundly decr in SVR that is refractory to fluids and vasopressors AFTER cardiopulmonary bypass).
This works by preventing nitric oxide-induced vasodilation.
Which local anesthetic has the strongest vasodilator effect?
Procaine due to its degradation product: dimethylaminoethanol (DEAE)
What level is the cervical plexus block needed for CEA?
C2-C4: both superficial and deep blocks required
Maximum dose of plain bupivicaine vs bupivicaine with epinephrine?
2.5 mg/kg vs. 3 mg/kg
Maximum dose of plain ropivicaine vs ropivicaine with epinephrine?
3 mg/kg vs 3.5 mg/kg
Maximum dose of plain mepivicaine vs mepivicaine with epinephrine?
5 mg/kg vs. 7 mg/kg
brachial plexus nerves located where in relation to axillary artery?
3 o’clock: ulnar nerve
6 o’clock: radial nerve (always closest to humerus)
10 o’clock: median nerve
Factors that decrease the rate of intravenous placement of epidural catheters?
lateral position (2ndry to a decrease in venous engorgement)
fluid administered through the epidural needle prior to catheter insertion
use of wire-embedded catheters
having 6cm or less of catheter in epidural space
using single-orifice catheters (but inferior pain control)