quiz 6 Flashcards
Labs need to be what for regional block?
Platelets >100k
PT/INR, aPTT < 2x normal value
PT: 11 - 13.5
INR: 0.8 - 1.1
PTT: 25 - 35
issue with pts who have preexisting nerve injuries?
can have prolonged or permanent block
intrallipid dosing
1.5ml/kg/min bolus, max 8ml/kg
which drug not a good motor blocker?
bupivicaine
DOA of ropiv, bupiv, lido? with Epi?
Ropiv: 2-6h, N/A w/epi
Bupiv: 2-4, 3-4 w/epi
Lido: 30min-2h, up to 3h w/epi
2% lido has how much per ml?
20mg per mL
just move decimal of percentage over 1 to get answer
1:200,000 solution to Epi ratio?
take second number and divide 1 million into it so – 5 mcg/ml
spraying local in an area to get the nerve, what technique?
field block technique
used for incision
parasthesia technique?
Block needle is inserted in proximity of the target nerve or nerve plexus
When needle makes direct contact with a sensory nerve, a paresthesia is elicited and the LA is injected
current and interval of nerve stimulator technique?
0-5 mA
1-2 Hz
what implies intraneural needle placement?
what about close to nerve?
muscle contraction elicited at < 0.2 mA
less than 0.5 mA – close to nerve
how much injected via nerve stimulator placement dose?
30-40 mL in divided doses with gentle aspiration
Ultrasound uses high-frequency sound waves emitted from _____________ that travel at different rates through tissues of different densities, returning a signal to the transducer. Range?
piezoelectric crystals
1-20 MHz
solid organs, deep structures have what echogenicity?
hypoechoic
diaphragm, gallstones, bone, pericardium have what echogenicity?
hyperechoic
fluid and blood filled structures have what echogenicity?
anechoic
look at slide 18
.
Nerves are best imaged in________ (_______)
cross-section
short axis
(seen as honeycomb appearance)
The nerve appears as a single circular ________ structure with internal _________ circles
hyperechoic
hypoechoic
preferred plane view?
longitudinal/in-plane alignment
Advantages of Continuous PNB
Reduction in resting and dynamic pain Reduction in supplemental analgesia requirements Reduction in opioid related side effects Reduction in sleep disturbance Improved patient satisfaction Improved patient ambulation Accelerated resumption of passive joint range-of-motion Reduced time to discharge
Complications of Continuous PNB
Systemic local anesthetic toxicity Catheter retention Retroperitoneal hematoma Infection Increased risk of falling (femoral nerve catheter) Nerve injury
which LAs preferred for continuous and why?
Long acting
better effect on sensory and less effect on motor
Brachial Plexus Blocks
Supraclavicular block
Interscalene block
Infraclavicular block
Axillary block
Terminal Nerve Blocks
Digital nerve blocks Intercostobrachial nerve block Median nerve block Musculocutaneous nerve block Ulnar nerve block Radial nerve block
intravenous regional anesthesia
Bier block
interscalene block blocks what the most? good for what surgery? What area does injection happen?
c5-c7
involving the shoulder and the upper arm
(not appropriate for surgery at or distal to the elbow)
Roots
what needs to be considered when doing a total shoulder and an interscalene block?
For complete surgical anesthesia of the shoulder, the C3-C4 cutaneous branches may need to be supplemented with a superficial cervical plexus block or local infiltration
A properly performed interscalene block will invariably block the _______ ________ nerve – will block one side of diaphragm so don’t do double block
ipsilateral (same side)
phrenic
a condition marked by a contracted pupil, drooping upper eyelid, and local inability to sweat on one side of the face, caused by damage to sympathetic nerves on that side of the neck.
Horner’s syndrome
myosis, ptosis, anhidrosis
Other considerations with Interscalene block
- Horner’s syndrome
- RLN involvement
- Vertebral artery involvment (immediate seizure)
- Spinal or epidural injection (could get full spinal)
- Pneumothorax
where does brachial plexus come out b/w in neck?
B/w anterior and middle scalene muscle
interscalene triangle
Supraclavicular block: Good for what surgeries? What is biggest risk? What area injected?
surgical procedures at or distal to the elbow
Pneumothorax
Divisions
Complications of Supraclavicular block
- Horner’s syndrome
- Ipsilateral phrenic nerve palsy in ~50% of patients
- Pneumothorax
- Subclavian artery puncture
- Recurrent laryngeal nerve palsy
Infraclavicular Block: What level blocked? What spared? What surgery?
Cords
surgical procedures at or distal to the elbow
The intercostobrachial nerve is spared (T2 dermatome)
Axillary block: What nerves? What does it block? What level?
Median and Ulner
entire arm distal to elbow
distal portion of cords
favored sites for terminal nerve blocks?
the elbow and the wrist
Bier block: duration? Common surgery?
45-60 mins
Carpel tunnel release
look at slide 48
.
Peripheral Nerve Blocks of the Trunk
Superficial Cervical Plexus Block
Paravertebral Block
Intercostal Block
Transverse Abdominis Plane Block
highest risk of toxicity?
Bier block d/t IV
Horner’s syndrome - may result from proximal tracking of local anesthetic and blockade of sympathetic fibers to the ____________.
cervicothoracic ganglion
For Axillary block: At the _______ border of the _________ muscle, the cords of the brachial plexus form large terminal branches
lateral
pectoralis minor
