Regional Anesthesia — MCQs

A 46-year-old male patient was given a subarachnoid block with heavy bupivacaine by the anesthetist. After 10 minutes, he was found to have a blood pressure of 72/44 mm Hg and a heart rate of 52/min. On checking the level of block, it was found to be T6. What is the likely explanation for the bradycardia?

Q212

What is the most common complication seen after neuraxial block (spinal/epidural anesthesia)?

Regional Anesthesia Indian Medical PG Practice Questions and MCQs

Question 211: A 46-year-old male patient was given a subarachnoid block with heavy bupivacaine by the anesthetist. After 10 minutes, he was found to have a blood pressure of 72/44 mm Hg and a heart rate of 52/min. On checking the level of block, it was found to be T6. What is the likely explanation for the bradycardia?

A. Bezold-Jarisch reflex (Correct Answer)
B. Bainbridge reflex
C. Reverse Bainbridge reflex
D. Block of Cardio-accelerator fibers of sympathetic origin

Explanation: ***Bezold-Jarisch reflex*** - The **Bezold-Jarisch reflex** is a cardioinhibitory reflex triggered by severe hypovolemia or decreased venous return, which can be seen with high spinal blocks. In this reflex, activation of left ventricular mechanoreceptors results in paradoxical **bradycardia**, **peripheral vasodilation**, and **hypotension**. - In a subarachnoid block, sympathetic outflow is blocked, leading to **vasodilation**, decreased venous return, and reduced ventricular filling. This triggers the reflex, manifesting as bradycardia and hypotension. *Bainbridge reflex* - The **Bainbridge reflex** (also known as the atrial reflex) is an increase in heart rate due to an increase in central venous pressure. - It would typically cause **tachycardia** in response to increased right atrial volume, which is the opposite of what is seen in the patient. *Block of Cardio-accelerator fibers of sympathetic origin* - **Cardio-accelerator fibers** originate between T1-T4. While a block at T6 would affect peripheral sympathetic outflow causing vasodilation, it would not directly block these specific cardio-accelerator fibers. - While sympathetic blockade contributes to hypotension, this specific mechanism does not provide the primary explanation for the observed profound **bradycardia** in this patient. *Reverse Bainbridge reflex* - There is no well-recognized physiological reflex termed the "Reverse Bainbridge reflex" that accurately describes this clinical scenario. - The patient's symptoms are consistent with known cardiovascular reflexes triggered by profound sympathetic blockade and decreased venous return.

Question 212: What is the most common complication seen after neuraxial block (spinal/epidural anesthesia)?

A. Bradycardia
B. Hypotension (Correct Answer)
C. Nausea
D. Anxiety

Explanation: **Hypotension** - **Sympathetic blockade** from neuraxial anesthesia leads to **vasodilation** and reduced venous return, causing a drop in blood pressure. - This is the most frequently encountered adverse effect, affecting a significant percentage of patients undergoing spinal or epidural blocks. *Bradycardia* - While possible due to **decreased preload** and the **Bezold-Jarisch reflex**, it is less common than hypotension. - Severe bradycardia is usually managed with atropine or epinephrine if hypotension is also present. *Nausea* - Nausea can occur due to **hypotension-induced cerebral hypoperfusion** or by the **unopposed parasympathetic activity** stimulating the GI tract. - However, nausea is a symptom often secondary to hypotension, making hypotension the primary and more common complication. *Anxiety* - Anxiety can be a psychological response to the procedure itself, but it is not a direct physiological complication of the neuraxial block. - It's a subjective feeling and not a direct consequence of the pharmacological effects of the anesthetic, unlike the other options.

Practice by Chapter

Neuraxial Anatomy

Practice Questions

Spinal Anesthesia

Practice Questions

Epidural Anesthesia

Practice Questions

Combined Spinal-Epidural Anesthesia

Practice Questions

Peripheral Nerve Blocks: Upper Extremity

Practice Questions

Peripheral Nerve Blocks: Lower Extremity

Practice Questions

Truncal Blocks

Practice Questions

Ultrasound-Guided Regional Anesthesia

Practice Questions

Complications of Regional Anesthesia

Practice Questions

Regional Anesthesia in Pediatric Patients

Practice Questions

Regional Anesthesia in Obstetrics

Practice Questions

Continuous Peripheral Nerve Catheters

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free