UPPER EXTREMITY BLOCKS
This brachial plexus approach targets the roots and trunks between the anterior and middle scalene muscles, and is the workhorse for shoulder surgery.
What is the interscalene block?
Performed just below the inguinal crease using the femoral artery and iliopsoas as landmarks, this block covers the anterior thigh and much of the knee.
What is the femoral nerve block?
This fascial plane block deposits local anesthetic between the internal oblique and transversus abdominis muscles for anterior abdominal wall analgesia.
What is the transversus abdominis plane (TAP) block?
This physicochemical property of a local anesthetic is the primary determinant of its potency.
What is lipid solubility?
Tinnitus, perioral numbness, and a metallic taste minutes after a block are the classic early warning signs of this emergency.
What is local anesthetic systemic toxicity (LAST)?
With frequencies in the 6–13 MHz range, this transducer gives the best resolution for superficial blocks such as interscalene and supraclavicular.
What is a high-frequency linear array probe?
Occurring in up to 100% of interscalene blocks with standard volumes, this predictable side effect is why the block is avoided in severe respiratory disease.
What is hemidiaphragmatic paresis (phrenic nerve palsy)?
This motor-sparing alternative to a femoral block targets the terminal sensory branches deep to the sartorius in the mid-thigh.
What is the adductor canal block?
In this block, local anesthetic is deposited on the transverse process deep to the erector spinae muscles — widely used for thoracic surgery and rib fractures.
What is the erector spinae plane (ESP) block?
This property determines onset speed: the closer it is to physiologic pH, the faster the block sets up.
What is the pKa?
This is the recommended initial bolus of 20% lipid emulsion in an adult over 70 kg with local anesthetic systemic toxicity.
What is 100 mL over 2–3 minutes (approx. 1.5 mL/kg lean body weight)?
Hypoechoic fascicles embedded in a hyperechoic connective tissue matrix give peripheral nerves this classic short-axis sonographic appearance.
What is the honeycomb appearance?
The “corner pocket” — the junction of the first rib and the subclavian artery — is a key target landmark in this clavicular-level block.
What is the supraclavicular block?
Targeting the genicular branches of the tibial and common peroneal nerves, this block covers the posterior knee capsule and is paired with an adductor canal block for total knee arthroplasty.
What is the IPACK block (infiltration between the popliteal artery and capsule of the knee)?
This is the dermatome that must be covered for lower abdominal surgery, corresponding to the level of the umbilicus.
What is T10?
This physicochemical property correlates most closely with duration of action of a local anesthetic.
What is protein binding?
Of the amide local anesthetics in common use, this one carries the highest risk of cardiac arrest refractory to conventional resuscitation.
What is bupivacaine?
Bone and air prevent sound transmission, producing this artifact that obscures everything deep to them — a common problem when scanning near the first rib.
What is acoustic shadowing?
In the costoclavicular approach to this block, all three cords sit clustered lateral to the axillary artery, making a single injection reliable.
What is the infraclavicular block?
The popliteal block is performed at or just proximal to the point where the sciatic nerve divides into these two branches.
What are the tibial and common peroneal nerves?
For a rectus sheath block, local anesthetic is deposited between the rectus abdominis muscle and this specific layer.
What is the posterior rectus sheath?
This is the accepted maximum dose of lidocaine, in mg/kg, when administered with epinephrine.
What is 7 mg/kg?
Injecting this extended-release formulation within 20 minutes of lidocaine can trigger immediate release of bupivacaine and a systemic toxicity risk.
What is liposomal bupivacaine (Exparel)?
An opening injection pressure above 15 psi, or unexpected resistance, should raise suspicion for this needle tip position.
What is intraneural (intrafascicular) injection?
Because it exits the sheath proximally, this terminal nerve — found within the coracobrachialis muscle — must be blocked separately during an axillary block.
What is the musculocutaneous nerve?
The PENG block deposits local anesthetic in the plane between the psoas tendon and this bony landmark.
What is the superior pubic ramus (at the level of the iliopubic eminence)?
Per ASRA guidelines, this is the minimum interval between a prophylactic dose of enoxaparin 40 mg daily and neuraxial needle placement or catheter removal.
What is 12 hours?
Marketed as a less cardiotoxic option, this agent is the S(−)-enantiomer of bupivacaine.
What is levobupivacaine?
A saturation gap and chocolate-brown blood after a large dose of benzocaine or prilocaine point to this condition, treated with methylene blue.
What is methemoglobinemia?
On a supraclavicular scan, this hyperechoic structure lying immediately deep and posterolateral to the plexus must be identified before every needle pass.
What is the pleura (with the first rib)?