Regional Anesthesia Practice Questions

Q: Contraindications to epidural analgesia include the following except

Hypertension. ***Hypertension*** - While careful monitoring is needed, **uncontrolled hypertension** is not an absolute contraindication to epidural analgesia. - Epidural analgesia can sometimes even help to lower blood pressure, which might be beneficial in certain hypertensive patients. *Infection over the back* - This is a significant contraindication due to the risk of introducing bacteria into the **epidural space**, leading to severe infections like **epidural abscess** or **meningitis**. - A local infection could spread to the central nervous system, causing grave complications. *Raised intracranial pressure* - This is a contraindication because a sudden decrease in **cerebrospinal fluid pressure** from epidural needle insertion can exacerbate herniation in patients with **raised ICP**. - The procedure itself can further alter intracranial dynamics, posing a significant risk. *Coagulopathy* - **Coagulopathy**, whether due to medication (e.g., anticoagulants) or a pre-existing medical condition, is a major contraindication. - There is an increased risk of **epidural hematoma**, which can compress the spinal cord and lead to permanent neurological damage.

Q: What is the name of the nerve block technique shown in the image?

Intra-arterial anesthesia. ***Intra-arterial anesthesia*** - The image shows a **cannula inserted directly into an artery**, indicated by the blood reflux and the context of anesthesia, suggesting direct drug delivery into the arterial system. - This method is used for specific types of regional pain management or diagnostic procedures where direct arterial access is required for **localized drug distribution**. *Bier's block* - A Bier's block, or **intravenous regional anesthesia**, involves injecting local anesthetic into a **vein** in an extremity after it has been exsanguinated and isolated by a tourniquet. - The image clearly shows a **bright red blood flash**, characteristic of arterial cannulation, not venous. *Regional anesthesia* - This is a broad term referring to the **anesthesia of a specific region** of the body and encompasses various techniques. - While intra-arterial anesthesia is a type of regional anesthesia, "regional anesthesia" itself is too general to specifically describe the technique shown. *Axillary block* - An **axillary block** is a type of peripheral nerve block targeting the brachial plexus in the axilla to anesthetize the arm. - The image does not depict the axillary region or the characteristic needle placement for an axillary block; instead, it shows direct vascular access.

Q: Which nerve is targeted in the nasociliary nerve block?

Nasociliary nerve. ***Nasociliary nerve*** - A nasociliary nerve block specifically targets the **nasociliary nerve** itself. - This block is used to anesthetize the sensory innervation of structures supplied by the nasociliary nerve, such as parts of the **nasal cavity**, **eyeball**, and **skin of the nose**. *Greater palatine nerve* - The **greater palatine nerve** supplies sensation to the posterior hard palate and is targeted in a **greater palatine nerve block**. - This nerve is a branch of the **maxillary nerve** and is primarily involved in dental and palatal anesthesia. *Sphenopalatine nerve* - The **sphenopalatine nerve**, or pterygopalatine ganglion, contains sensory fibers for the nasal cavity, palate, and pharynx, and its block is distinct from a nasociliary block. - A **sphenopalatine ganglion block** is mainly used for conditions like cluster headaches and facial pain, not for direct eyeball sensation. *Anterior ethmoidal nerve* - The **anterior ethmoidal nerve** is a branch of the nasociliary nerve, but a nasociliary nerve block targets the main trunk, which includes all its branches. - While the anterior ethmoidal nerve supplies the anterior part of the nasal septum and lateral wall, it is a **component** of the nasociliary innervation rather than the sole target.

Q: The duration of spinal anaesthesia is based directly on:

Dose. ***Dose*** - The **total mass** (dose) of the local anesthetic administered directly influences the number of nerve fibers blocked and the duration of block. - A higher dose of a given local anesthetic generally leads to a **longer duration** of action in spinal anesthesia. *Height* - While patient height can influence the **spread** of spinal anesthesia due to differences in spinal column length, it does not directly determine the **duration** of the block. - The **volume** of the injectate, rather than the patient's height alone, affects the cranial spread of the anesthetic. *Total body fat* - Total body fat has **minimal direct impact** on the duration of spinal anesthesia since local anesthetics are injected directly into the cerebrospinal fluid, largely bypassing systemic fat distribution initially. - **Lipid solubility** of the drug affects its potency and duration within the neuraxis, not external body fat. *Age* - **Age** can influence the **spread** and **onset** of spinal anesthesia due to changes in cerebrospinal fluid volume and spinal cord compliance, but it is not the primary determinant of **duration**. - Older patients may experience a greater spread for a given dose, but the primary factor for duration remains the total drug dose.

Q: Spinal anaesthesia in an adult is given at this level:

L3-L4. ***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.

Q: All are true about management of PDPH except-

Early ambulation. ***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.

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

5%. ***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.

Q: First spinal anaesthesia was given by -

August Bier. ***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.

Q: Local anaesthetic usually used for retrobulbar block -

Bupivacaine. ***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.

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

Intravenous. ***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 1

Contraindications to epidural analgesia include the following except

Accepted Answer

Hypertension

Answer

Infection over the back

Answer

Raised intracranial pressure

Answer

Coagulopathy

Question 2

What is the name of the nerve block technique shown in the image?

Accepted Answer

Intra-arterial anesthesia

Answer

Bier's block

Answer

Regional anesthesia

Answer

Axillary block

Question 3

Which nerve is targeted in the nasociliary nerve block?

Accepted Answer

Nasociliary nerve

Answer

Greater palatine nerve

Answer

Sphenopalatine nerve

Answer

Anterior ethmoidal nerve

Question 4

The duration of spinal anaesthesia is based directly on:

Accepted Answer

Dose

Answer

Height

Answer

Total body fat

Answer

Age

Question 5

Spinal anaesthesia in an adult is given at this level:

Accepted Answer

L3-L4

Answer

T12-L1

Answer

L1-L2

Answer

L5-S1

Question 6

All are true about management of PDPH except-

Accepted Answer

Early ambulation

Answer

Hydration

Answer

Cerebral vasoconstriction - caffeine

Answer

Analgesic

Question 7

What is the concentration of lignocaine used for spinal anesthesia?

Accepted Answer

5%

Answer

50%

Answer

25%

Answer

5

Answer

75%

Question 8

First spinal anaesthesia was given by -

Accepted Answer

August Bier

Answer

Morton

Answer

Sicard

Answer

Corning

Question 9

Local anaesthetic usually used for retrobulbar block -

Accepted Answer

Bupivacaine

Answer

Prilocaine

Answer

Tetracaine

Answer

Procaine

Question 10

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

Accepted Answer

Intravenous

Answer

Dermal

Answer

Peribulbar region

Answer

Retrobulbar area

Regional Anesthesia — MCQs

Regional Anesthesia — MCQs

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