Regional Anaesthesia: Techniques MCQs

In the clinical scenario described, atropine by itself, may not be able to correct the hemodynamics, and the situations call for initiation of measures required in advanced cardiac life support If there is no pulse → chest compressions along with → administration of epinephrine may be the best course of action Reference : ACLS guidelines AHA

The clinical manifestations of bone cement implantation syndrome include Hypoxia (increased pulmonary shunt) Hypotension Arrhythmias (including heart block and sinus arrest) Pulmonary hypertension (increased pulmonary vascular resistance) Decreased cardiac output Reference: Morgan and Mikhail's clinical anesthesiology 6th edition pg. 805.

Caudal epidural anesthesia is a common regional technique in pediatric patients. Caudal anesthesia involves needle or catheter penetration of the sacrococcygeal ligament covering the sacral hiatus that is created by the unfused S4 and S5 laminae. The hiatus may be felt as a groove or notch above the coccyx and between two bony prominences, the sacral cornua. The posterior superior iliac spines and the sacral hiatus define an equilateral triangle Reference: Morgan and Mikhail's clinical anesthesiology 6th edition pg 987.

Testicular innervation can be traced up to the T10 dermatomal level. For this reason, any operation that involves manipulation or traction on the testicles must have adequate anesthesia to prevent pain. This can be achieved with spinal or epidural anesthesia, which is associated with a T10 level of blockade. Reference: Miller, ed 8, p 2219

Blood supply to the spinal cord comes from several sources. The anterior spinal artery is derived from the vertebral arteries and runs the entire length of the spinal cord and supplies the anterior two thirds of the cord. There are segmental arteries from the aorta that join the anterior spinal artery to help supply the spinal cord. One of the larger arteries is called the artery of Adamkiewicz, which arises from the lower thoracic area (T9-T12). Damage to this artery can lead to ischemia for the lower two thirds of the spinal cord and can result in paraplegia. The posterior one third of the cord is supplied by two posterior spinal arteries that also arise from the vertebral arteries and receive some blood supply from the segmental arteries. Reference: Miller: Miller's Anesthesia, ed 8, p 1131.

Explanation: It is the least likely layer to be punctured during epidural anesthesia, as it is not meant to be breached during the procedure. Sequence of structures typically traversed in epidural anesthesia: Skin Subcutaneous tissue Supraspinous ligament (Option C ruled out) Interspinous ligament (Option D ruled out) Ligamentum flavum (Option B ruled out) The epidural space lies just after the ligamentum flavum, making deeper layers-like the dura mater- L ess likely to be punctured if the procedure is done correctly.

Explanation: In adults , the spinal cord ends at the level of the: Lower border (inferior end) of L1 vertebra. Sometimes can extend to upper L2 , but most commonly lower L1. This terminal portion of the spinal cord is called the conus medullaris . Explanation for other options: Upper end of L1 (option A): Incorrect. The level is too high. The spinal cord usually extends a bit lower. Upper end of L3 (option B): Incorrect. This is too low; spinal cord ends well above this level in adults. Lower end of L3 (option D): Incorrect. This is true in neonates or infants , not adults.

Circumoral numbness and apprehension immediately following administration of lidocaine suggest an intravascular injection of local anesthetic. Abrupt tachycardia strongly suggests intravascular injection of epinephrine. Reference: Morgan and Mikhail’s clinical anaesthesiology 6th edition pg 272.