Regional Anesthesia — MCQs

Regional Anesthesia Indian Medical PG Practice Questions and MCQs

Question 141: Spinal anaesthesia in an adult is given at this level:

A. L3-L4 (Correct Answer)
B. T12-L1
C. L1-L2
D. L5-S1

Explanation: ***L3-L4*** - This intervertebral space is a **safe and common site** for spinal anaesthesia in adults because the **spinal cord typically terminates at L1-L2** in adults. - Inserting the needle at L3-L4 minimizes the risk of **spinal cord injury** while still allowing access to the cerebrospinal fluid. *T12-L1* - This level is **too high** for routine spinal anaesthesia in adults, as it is often at or very near the **conus medullaris** (the end of the spinal cord). - Puncture at this level carries a **significant risk of direct spinal cord injury**. *L1-L2* - While technically possible, this level is still considered **higher risk** as it is often the **terminal end of the spinal cord** in adults. - The **cauda equina** is present below L1-L2, but the L3-L4 space offers a greater margin of safety. *L5-S1* - This intervertebral space is generally **too low and difficult to access** for consistent and effective spinal anaesthesia. - The **iliac crests typically align with L4**, making the L3-L4 or L4-L5 spaces more accessible for spinal puncture.

Question 142: All are true about management of PDPH except-

A. Early ambulation (Correct Answer)
B. Hydration
C. Cerebral vasoconstriction - caffeine
D. Analgesic

Explanation: ***Early ambulation*** - **Early ambulation** was historically thought to worsen PDPH but is now understood to have no significant impact on its incidence or severity. - While not directly a treatment, it is not contraindicated and does not preclude other management strategies; therefore, stating it is "true about management" is the exception as it's often a misconception. *Hydration* - **Hydration**, especially intravenous fluids, is a supportive measure for PDPH, as it can help maintain cerebral fluid volume. - This can potentially increase CSF pressure and alleviate symptoms. *Cerebral vasoconstriction - caffeine* - **Caffeine** induces **cerebral vasoconstriction**, which helps reduce cerebral blood volume and consequently decreases the intracranial pressure gradient, alleviating PDPH. - It also has mild analgesic properties. *Analgesic* - **Analgesics**, such as NSAIDs or acetaminophen, are used for symptomatic relief of the headache pain associated with PDPH. - They address the pain but do not target the underlying cause of CSF leakage.

Question 143: Commonest complication of celiac plexus block is

A. Seizures
B. Bradycardia
C. Retroperitoneal hematoma
D. Hypotension (Correct Answer)

Explanation: ***Hypotension*** - **Hypotension** is the most common complication due to the **sympathectomy** caused by the block, leading to widespread vasodilation. - This effect is often self-limiting but may require **fluid boluses** or vasopressors. *Seizures* - Seizures are an extremely **rare complication** and are typically associated with systemic toxicity of local anesthetics, not directly with the mechanism of a celiac plexus block itself. - This would usually occur due to **intravascular injection** or excessive systemic absorption. *Bradycardia* - **Bradycardia** is less common than hypotension and is more typically associated with blocks that affect the **parasympathetic nervous system**, which is not the primary target of a celiac plexus block. - While it can occur, it is not the most frequent side effect. *Retroperitoneal hematoma* - A **retroperitoneal hematoma** is a serious complication, but it is less common than hypotension, occurring due to trauma to blood vessels during needle insertion. - The risk is higher with **anticoagulated patients** or complex needle trajectories.

Question 144: What is the concentration of lignocaine used for spinal anesthesia?

A. 50%
B. 25%
C. 5
D. 75%
E. 5% (Correct Answer)

Explanation: ***5%*** - **Lignocaine (lidocaine)** for spinal anesthesia is commonly prepared as a 5% solution in 7.5% dextrose to ensure a hyperbaric solution. - This higher concentration of lignocaine (compared to other regional blocks) is used to achieve a rapid onset and dense sensory and motor block required for spinal anesthesia. *50%* - A **50% concentration** of lignocaine is far too high and would be severely neurotoxic if administered intrathecally. - Such high concentrations are not used for any clinical anesthetic purposes due to extreme toxicity. *25%* - A **25% concentration** of lignocaine is also excessively high and would lead to severe local and systemic toxicity if used for spinal anesthesia. - This concentration is not clinically relevant for any regional anesthetic technique. *5* - The value "5" without units is ambiguous; however, if it implies 500% or an unstated high percentage, it would be extremely toxic and not used clinically. - The standard way to express concentration for spinal anesthetics is in percentages (e.g., 5%). *75%* - A **75% concentration** of lignocaine is dangerously high and would cause immediate and severe neurotoxicity and systemic effects. - This concentration is not used in any clinical setting for anesthetic purposes.

Question 145: First spinal anaesthesia was given by -

A. August Bier (Correct Answer)
B. Morton
C. Sicard
D. Corning

Explanation: ***August Bier*** - **August Bier** performed the first successful spinal anesthetic on August 16, 1898. - He used **cocaine** for this procedure and personally experimented with himself and his assistant, Dr. Hildebrandt. *Morton* - **William T.G. Morton** is credited with demonstrating the first successful public use of **ether anesthesia** for surgery in 1846. - His contributions were fundamental to the development of general anesthesia, not specifically spinal anesthesia. *Sicard* - **Jules Sicard** was a French neurologist who, along with **Anatole Cathelin**, is credited with describing **epidural anesthesia** (then called paravertebral extradural injection) in the early 20th century (1901). - This is distinct from spinal anesthesia, which involves injecting into the subarachnoid space. *Corning* - **James Leonard Corning** performed experiments with cocaine injections into the spinal cord areas of animals and humans in 1885 and published findings suggestive of spinal neural blockade. - While his work was foundational and predated Bier, his primary aim was to achieve **nerve block** in the epidural space, and his procedures did not reliably result in subarachnoid injection as Bier's did.

Question 146: Local anaesthetic usually used for retrobulbar block -

A. Prilocaine
B. Bupivacaine (Correct Answer)
C. Tetracaine
D. Procaine

Explanation: ***Bupivacaine*** - **Bupivacaine** is a long-acting local anaesthetic commonly chosen for retrobulbar blocks due to its prolonged duration of action, providing extended pain relief and akinesia. - Its slower onset compared to some other agents is often acceptable for ophthalmic procedures where prolonged block is more critical than rapid onset. *Prilocaine* - **Prilocaine** is an intermediate-acting local anaesthetic, generally having a shorter duration of action than bupivacaine, making it less ideal for procedures requiring sustained blockade. - High doses of prilocaine are associated with the risk of **methemoglobinemia**, which is a significant consideration in its use. *Tetracaine* - **Tetracaine** is primarily used as a topical anaesthetic, particularly for surface anaesthesia of the eye (e.g., prior to drops or contact lens insertion). - It is not typically used for injection in retrobulbar blocks due to its high systemic toxicity when administered via injection and its short duration of action. *Procaine* - **Procaine** is a short-acting ester-type local anaesthetic with a rapid onset but very brief duration of action. - Its short duration makes it unsuitable for retrobulbar blocks where prolonged akinesia and anaesthesia are desired for the surgical procedure.

Question 147: In Bier's block anesthetic agent given by which route?

A. Dermal
B. Peribulbar region
C. Intravenous (Correct Answer)
D. Retrobulbar area

Explanation: ***Intravenous*** - In a **Bier's block** (intravenous regional anesthesia), the anesthetic agent is injected directly into a **peripheral vein** of the limb to be anesthetized. - A **tourniquet** is applied proximally to the injection site to prevent the anesthetic from reaching systemic circulation and to confine it to the limb. *Dermal* - **Dermal administration** involves applying the anesthetic agent to the skin surface, typically for topical numbing or local infiltration. - This route is used for procedures like laceration repair or skin biopsies and would not achieve regional anesthesia for a limb. *Peribulbar region* - The **peribulbar region** refers to the area around the eyeball, and anesthetic agents injected here are used for **ocular anesthesia** during eye surgeries. - This route is specific to ophthalmology and completely unrelated to limb anesthesia. *Retrobulbar area* - The **retrobulbar area** is located behind the eyeball, and injections here provide a deeper form of **ocular anesthesia** compared to peribulbar blocks. - Like peribulbar injections, this method is exclusively used for eye procedures and not for limb blocks.

Question 148: Post Spinal Headache can last for

A. Upto 10 months
B. Upto 10 hours
C. 7 - 10 days (Correct Answer)
D. Upto 10 min

Explanation: ***7 - 10 days*** - **Post-dural puncture headache (PDPH)** typically has a self-limiting course, with symptoms usually resolving within **one to two weeks**. - The duration is often attributed to the continued leakage of **cerebrospinal fluid (CSF)** through the dural puncture site. *Upto 10 months* - While chronic daily headache can occur following dural puncture, a duration of **10 months** is extremely long and atypical for uncomplicated PDPH. - Such prolonged headaches would warrant investigation for alternative or **secondary causes** of headache. *Upto 10 hours* - Although some mild headaches after dural puncture may resolve quickly, a typical **post-dural puncture headache** usually persists for at least **24-48 hours** to several days. - Headaches resolving within **10 hours** are often considered to be non-PDPH or a mild, transient headache. *Upto 10 min* - A headache lasting only **10 minutes** is highly unlikely to be a true post-dural puncture headache (PDPH). - PDPH is characterized by a **positional headache** that worsens in the upright position and improves with recumbency, typically lasting for days.

Question 149: An anesthesia resident was giving spinal anesthesia when the patient had sudden aphonia and loss of consciousness. What could have happened?

A. Vasovagal attack
B. Intravascular injection
C. Total spinal (Correct Answer)
D. Partial spinal

Explanation: ***Total spinal*** - A **total spinal** involves widespread blockade of spinal nerves, including those supplying the brainstem, leading to **aphonia** and **loss of consciousness** due to severe hypotension and respiratory depression. - This occurs when the local anesthetic spreads extensively cephalad, affecting the cervical and cranial nerves. *Vasovagal attack* - While a vasovagal attack can cause **loss of consciousness** due to transient hypotension and bradycardia, it does not typically cause **aphonia**. - Symptoms usually include nausea, pallor, and sweating, and recovery is often rapid once the patient is recumbent. *Intravascular injection* - **Intravascular injection** of local anesthetic during spinal anesthesia can cause systemic toxicity, leading to seizures, cardiac arrhythmias, or cardiac arrest, but not typically sudden **aphonia** as the primary presenting symptom. - It's a risk, but the presenting symptoms usually differ. *Partial spinal* - A **partial spinal** refers to inadequate or uneven spread of the local anesthetic, resulting in unblocked dermatomes or weak motor blockade. - It would not cause sudden **aphonia** or **loss of consciousness** as a presenting symptom.

Question 150: True about Epidural anesthesia:

A. Given in subarachnoid space
B. Effects start immediately
C. C/I in coagulopathies (Correct Answer)
D. All of the options

Explanation: ***C/I in coagulopathies*** - **Coagulopathy** is a **contraindication** for epidural anesthesia due to the significant risk of **epidural hematoma** formation. - An epidural hematoma can compress the spinal cord, leading to **neurological damage** or **paralysis**. *Given in subarachnoid space* - Epidural anesthesia involves injecting anesthetic agents into the **epidural space**, which is superficial to the **dura mater**. - Injection into the **subarachnoid space** is characteristic of **spinal anesthesia**, not epidural anesthesia. *Effects start immediately* - The onset of action for epidural anesthesia is typically **slower** compared to spinal anesthesia, usually taking **10-20 minutes**. - This delay is due to the need for the anesthetic to diffuse across the dura and nerve roots to reach the spinal cord. *All of the options* - This option is incorrect because only one of the statements provided (C/I in coagulopathies) is true regarding epidural anesthesia. - The other statements about the injection site and onset of action are false.

Practice by Chapter

Neuraxial Anatomy

Practice Questions

Spinal Anesthesia

Practice Questions

Epidural Anesthesia

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Combined Spinal-Epidural Anesthesia

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Peripheral Nerve Blocks: Upper Extremity

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Peripheral Nerve Blocks: Lower Extremity

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Truncal Blocks

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Ultrasound-Guided Regional Anesthesia

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Complications of Regional Anesthesia

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Regional Anesthesia in Pediatric Patients

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Regional Anesthesia in Obstetrics

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Continuous Peripheral Nerve Catheters

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