Assisting the Anesthesia Provider with Peripheral Nerve Blocks

Comprehensive practice questions covering the history, benefits, common types, equipment, procedures, and complications of peripheral nerve blocks based on the lecture notes.

When did surgeons popularize regional anesthesia and for what specific purpose?

In the late 1900’s; they used it to block “surgical shock!”

What are the primary intraoperative and postoperative benefits of peripheral nerve blocks (PNBs)?

PNBs provide intraoperative anesthesia and analgesia, as well as postoperative analgesia.

According to historical data, what percentage of ambulatory orthopedic surgery patients experienced poor pain control within the first $48$ hours using conventional management?

$$40\%$$

List four clinical benefits of Peripheral Nerve Blocks regarding patient recovery and safety.

1. Lower complication rate. 2. Better recovery. 3. Patient satisfaction. 4. Cost-effectiveness.

Which specific consequences of general, spinal, and epidural anesthesia do PNBs help avoid?

Airway manipulation and hemodynamic consequences.

Which upper extremity block is used for shoulder, arm, and elbow surgery?

Interscalene block

Which block is appropriate for surgery on the entire upper extremity?

Supraclavicular block

What are the indications for an Infraclavicular block versus an Axillary block?

Infraclavicular blocks are for elbow, forearm, and hand surgery; Axillary blocks are specifically for forearm and hand surgery.

What are the common clinical uses for a Lumbar plexus block?

Hip, anterior thigh, and knee surgery.

Which block is used for surgery on the tibia, ankle, and foot?

Sciatic nerve block

What are the indications for an Adductor Canal Block?

Total Knee, Tibia, and Fibula repairs.

List four contraindications for performing a Peripheral Nerve Block.

1. Uncooperative Patient (combative or demented). 2. Pediatric patient (requiring GA). 3. Blood coagulation disorder. 4. Pre-existing neuropathy or nerve injury.

What is the typical duration for a Continuous Peripheral Nerve Block (CPNB)?

$48-72$ hours (though well past $72$ hours is possible).

What specific emergency medication must be included in the resuscitation equipment for PNBs to treat local anesthetic toxicity?

INTRALIPIDS

What are the standard insulated needle sizes used for PNBs?

$2$, $4$, and $6$ inches.

Describe the anatomical difference between 'Intrafascicular' and 'Intraneural' injections.

Intrafascicular refers to injections within the fascicle; Intraneural refers to injections within the Endoneurium.

What is the proper patient positioning for an upper extremity nerve block?

Supine position with the head facing away from the side to be blocked; the arm should be abducted and flexed at the elbow.

In nerve stimulation, what is the initial amperage range and the final target range for acceptable stimulation?

Initial: $1.0-2.0\,mA$. Target: approximately $0.2-0.5\,mA$.

What frequency should the technician use for aspiration and injection once stimulation is successful?

Aspirate, then inject slowly while aspirating every $5\,ml$.

What EKG changes might indicate local anesthetic has been injected into a blood vessel?

Significant tachycardia (from epinephrine), arrhythmias, or ventricular fibrillation.

Why should an injection be immediately discontinued if significant resistance or pain is felt?

It may indicate an intraneural injection, which can cause permanent nerve injury with as little as $0.5-1.0\,ml$ of local anesthetic.

What are the early signs of Local Anesthetic Systemic Toxicity (LAST)?

Altered mental status, seizure, respiratory depression, hypotension, and cardiac arrhythmia.

What are examples of block-specific delayed complications?

Pneumothorax and phrenic nerve palsy.