EXPLANATION FOR QUESTION 16

QUESTION 16

This patient is experiencing hypotension as a side effect of epidurnl anesthesia. Hypotension occurs in up to 10% of epidurals given

during labor and can be easily prevented and treated. Continuous epidural analgesia involves infusion of a low concentration of a

local anesthetic into the epidural space at the L2-L5 level, blocking nerves responsible for labor pain. It is a highly effective modality

for pain relief in labor. Hypotension occurs when the sympathetic nerve fibers responsible for vascular tone are blocked, resulting in

vasodilation (venous pooling), decreased venous return to the right side of the heart, and decreased cardiac output Persistent,

untreated hypotension can result in decreased placental perfusion and can lead to fetal acidosis. It can be prevented by aggressive

intravenous fluid volume expansion prior to epidural placement. Treatment includes left uterine displacement (positioning patient on

the left side) to improve venous return, additional intravenous fluid bolus, or vasopressor administration.

(Choice A) Acute depression of myocardial contractility develops during myocardial infarction and is usually accompanied by chest

pain and dyspnea Hypotension occurs secondary to cardiogenic shock. This patient has no symptoms of myocardial infarction and it

is rare in a healthy 32-year-old.

(Choice B) Depression of cervical spinal cord and brainstem activity occurs when local anesthesia ascends toward the head, also

known as a "high spinal" or "total spinal," a dangerous complication of epidural anesthesia. It may happen with intrathecal injection

or overdose of the anesthetic. First signs include hypotension, bradycardia, and respiratory difficulty, and later, diaphragmatic

paralysis and possibly cardiopulmonary arrest

(Choice C) Leakage of cerebral spinal fluid may occur if the dura is inadvertently punctured during epidural placement. This results

in leakage of spinal fluid and is known as a "wet tap." Patients may experience postural headaches that are worse with sitting up

and improved with lying down after delivery. Hypotension is not characteristic

(Choice D) Progressive hypovolemia may be secondary to ongoing fluid and blood loss or electrolyte abnormalities. In an otherwise

healthy obstetric patient, volume depletion or electrolyte abnormalities are uncommon. Hemorrhage may accompany obstetric

complications such as uterine rupture, abruptio placenta, or placenta previa but is uncommon and is typically accompanied by vaginal

bleeding with or without abdominal pain

Educational objective:

Hypotension is a common side effect of epidural anesthesia. The cause of hypotension is blood redistribution to the lower extremities

and venous pooling from sympathetic blockade.



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