Choice of LA, 3 determinates:
1) desired onset
2) desired duration
3) desired motor/sensory block
Lidocaine (plain) max dose an DOA
Max dose 4 mg/kg
DOA 30 min-2 hours
Lidocaine (with epi) max dose an DOA
Max dose 7 mg/kg
DOA up to 3 hours
Bupivicaine (plain) max dose an DOA
Max dose 2 mg/kg
DOA 2-4 hours
Bupivicaine (with epi) max dose an DOA
Max dose 3 mg/kg
DOA 3-4 hours
Ropivicaine (plain) max dose an DOA
Max dose 5 mg/kg
DOA 2-6 hours
Ropivicaine (with eip) max dose an DOA
N/A
Which LA would be the best choice for a long 4-6 hour procedure?
Ropivicaine (plain) DOA 2-6 hours
What are the 4 block techniques?
1) Field block- targeting LA for terminal cutaneous nerves
2) Paresthesia- look & stab
3) Nerve stimulation- when needle close to motor nerve, muscle contracts
4) Ultrasound** (preferred)
For nerve stimulation, what conditions are optimal for LA injection?
When + muscle contraction @ <0.5 mA current, but not at 0.2 mA= intraneural placement
5 contraindications for PNB?
- Pt refusal
- LA allergy
- Local infection (infection risk/acidic tissue)
- Coagulopathy/anti-coagulant meds= hematoma risk
- With some brachial plexus blocks: severe pulm disease or preexisting contralateral phrenic nerve palsy or contralateral VC paralysis
What are the (6) general possible complications for PNB?
and special c/o for continuous and femoral?
- infection
- nerve injury
- hematoma
- local anesthetic systemic toxicity (LAST)
- catheter retention (for continuous)
- ↑ fall risk for femoral blocks
What are the 4 brachial plexus blocks?
1) Interscaline
2) Supraclavicular
3) Infraclavicular
4) Axillary
6 terminal nerve blocks of the upper extremity?
1) Median nerve
2) Ulnar nerve
3) Radial nerve
4) Musculocutaneous
5) Digital
6) Intercostobrachial
Which brachial plexus blocks have contraindications for
- Severe pulm disease or preexisting contralateral phrenic nerve palsy
- Contralateral VC paralysis
Interscaline and Supraclavicular (higher level)
1. Severe pulm disease or preexisting contralateral nerve pals- can block ipsilateral phrenic nerve => dyspnea, ↓PaO2, ↑ PaCO2
- Contralateral VC paralysis=> respiratory distress possible if block recurrent laryngeal nerve (also causes hoarseness)
What 2 factors are considered when choosing an US probe and what are the 2 choices ?
1) depth of target
2) needle angle approach relative to transducer
Linear probe= high frequency, high resolution/less penetration (best pic, good for superficial nerves)
Curvilinear probe= low frequency, low resolution/more penetration (best for deeper structures)
What are the sections of the brachial plexus and which blocks work on them?
Roots (C5-T1)- Interscaline block (mostly C5-C7) Trunks Divisions- Supraclavicular Cords- Infraclavicular Branches- Axillary
What is Horner’s Syndrome and with what blocks is it a risk?
Myosis, ptosis and anhydrosis from proximal tracking of LA to block sympathetic fibers of the cervicothoracic ganglion
Risk with interscaline and supraclavicular blocks
