Regional Anesthesia Practice Questions

Q: Spinal anesthesia is given at which of the following levels?

L2-4. **L2-4** - Spinal anesthesia is typically administered below the **termination of the spinal cord (conus medullaris)**, which usually ends around the L1-L2 vertebral level in adults. - The **L2-4 interspaces** are generally safe and commonly chosen to avoid accidental spinal cord injury while providing effective regional anesthesia. *Below L5 (caudal)* - Administering anesthesia "below L5" typically refers to a **caudal block**, which targets the sacral hiatus and is used for anesthesia of the perineum and lower extremities but is not considered spinal anesthesia. - While technically below the spinal cord, inserting a needle at this level doesn't directly access the **subarachnoid space** for spinal anesthesia and carries different indications and risks. *L1-2* - This level is generally avoided for routine spinal anesthesia, as the **spinal cord (conus medullaris)** can extend down to L2 in some adults. - Puncturing at this level carries a higher risk of **direct spinal cord trauma**, which can lead to neurological deficits. *Midline of thorax* - Administering spinal anesthesia in the **thoracic region** is extremely risky and not routinely performed for typical spinal blocks. - This area contains the **spinal cord throughout**, and accidental puncture or drug administration can cause severe neurological damage or high spinal block with cardiorespiratory compromise.

Q: Which of the following is not a contraindication for neuraxial block?

Patient on antihypertensive medication. ***Patient on antihypertensive medication*** - Antihypertensive medications are generally **not a contraindication** for neuraxial block; however, careful management of **blood pressure** especially following the sympathetic block is essential. - The primary concern is **hypotension** due to the sympathetic blockade, which can be managed with fluids and vasopressors, not an absolute contraindication. *Patient on clopidogrel* - **Clopidogrel** is an **antiplatelet agent** that increases the risk of **spinal hematoma** if a neuraxial block is performed. - This medication should typically be discontinued for a specific period before neuraxial procedures to minimize bleeding risk. *Local infection* - Performing a neuraxial block through an infected area increases the risk of introducing **pathogens into the subarachnial space**, leading to severe complications like **meningitis** or an **epidural abscess**. - This is an **absolute contraindication** to protect against central nervous system infection. *Platelet count < 50,000* - A **low platelet count** indicates impaired hemostasis, significantly increasing the risk of **bleeding** and the formation of a **spinal hematoma** following neuraxial puncture. - While exact thresholds vary, a platelet count below 50,000 is generally considered an **absolute contraindication** for neuraxial anesthesia.

Q: Which is not true about spinal anesthesia?

Produces complete sensory and motor paralysis below the level. ***Produces complete sensory and motor paralysis below the level*** - While spinal anesthesia produces significant sensory and motor blockade, it is rarely a **complete paralysis** below the level of injection, especially in terms of all muscle groups and deep sensation. - The degree of blockade depends on the **dose of anesthetic**, the patient's individual anatomy, and the spread of the drug within the cerebrospinal fluid, leading to a variable rather than absolute "complete" paralysis. *Useful for lower limb surgery* - Spinal anesthesia is **highly effective** and commonly used for lower limb surgeries as it provides excellent surgical anesthesia and postoperative analgesia. - It targets the nerve roots innervating the lower extremities, successfully blocking sensation and motor function, which is ideal for procedures like **knee or hip replacements**. *It produces more hemodynamic alteration than epidural anesthesia* - Spinal anesthesia typically causes a more **rapid and profound sympathetic blockade** than epidural anesthesia, due to direct and rapid diffusion of local anesthetic into the cerebrospinal fluid (CSF). - This rapid blockade often leads to a more significant and faster decrease in **blood pressure and heart rate** due to widespread vasodilation and reduced venous return. *Autonomic fibers are affected above the sensory level* - Sympathetic (autonomic) fibers are typically smaller and unmyelinated, making them **more susceptible to local anesthetic blockade** than sensory or motor fibers. - Therefore, the **sympathetic blockade** often extends two to three dermatomes higher than the sensory block, resulting in vasodilation and potential hemodynamic changes in areas above the perceived sensory level.

Q: Most common injection site infection in spinal anaesthesia

Staphylococcus. **Staphylococcus** - **_Staphylococcus_** species, particularly methicillin-sensitive _Staphylococcus aureus_ (MSSA) and methicillin-resistant _Staphylococcus aureus_ (MRSA), are the **most common culprits** in post-procedural infections like those following spinal anesthesia due to their presence on the skin. - These bacteria can cause various infections, from **superficial cellulitis** at the injection site to more serious complications like **meningitis** or an **epidural abscess**. *Bacteroides* - **_Bacteroides_** species are **anaerobic bacteria** commonly found in the gut flora, making them less likely to cause skin-puncture infections unless there is bowel injury or contamination. - While they can cause serious infections, they are **not typically associated** with superficial skin contamination leading to spinal anesthesia infections. *Pseudomonas* - **_Pseudomonas aeruginosa_** is known for causing opportunistic infections, especially in healthcare settings and in contact with water sources, but it is **not the most common cause** of injection site infections following spinal procedures. - Infections with **_Pseudomonas_** often present with a distinctive **grape-like odor** and a blue-green pus, which is not the typical presentation for initial injection site infections. *Streptococcus* - **_Streptococcus_** species can cause skin infections, but they are generally **less common than _Staphylococcus_** in injection site infections after spinal anesthesia. - While **Group A _Streptococcus_** can cause severe skin and soft tissue infections, it typically presents with **rapidly spreading cellulitis** rather than focal injection site issues.

Q: The site of action of local anaesthetic in epidural anesthesia is

Spinal nerve root. ***Spinal nerve root*** - Local anesthetics injected into the epidural space primarily act on the **spinal nerve roots** as they exit the spinal cord. - They also affect the **dorsal root ganglia** and the unmyelinated axons within the epidural space. *Anterior root of spinal nerve* - While the **anterior roots containing motor fibers** are affected, the local anesthetic's action isn't limited exclusively to them. - Sensory fibers in the **dorsal roots** are also blocked, contributing significantly to the analgesic effect. *Epidural neural tissue* - "Epidural neural tissue" is a too broad and non-specific term; the primary targets are the **nerve roots** themselves, not just any neural tissue within the epidural space. - This option does not specify which neural structures within the epidural space are the primary site of action. *Spinal cord* - Local anesthetics do not directly act on the **spinal cord parenchyma** in epidural anesthesia, as they do not typically penetrate the meninges to reach the cord in significant concentrations. - The medication exerts its effect outside the dura mater, primarily on the **nerve roots** before they enter the subarachnoid space.

Q: Centrineuraxial anaesthesia is not contraindicated in:

Patient on aspirin. ***Patient on aspirin*** - Aspirin is an **antiplatelet agent** that irreversibly inhibits cyclooxygenase, affecting platelet function but typically does not significantly increase the risk of **epidural hematoma** to contraindicate neuraxial anesthesia. - While careful consideration is needed, especially if combined with other anticoagulants, aspirin alone usually presents a **lower bleeding risk** compared to other anticoagulants. *Patient on anticoagulants* - Use of therapeutic anticoagulants (e.g., heparin, warfarin, novel oral anticoagulants) significantly increases the risk of **spinal or epidural hematoma**, which can lead to neurological deficits. - Therefore, these medications are generally considered a **contraindication** until they are stopped and coagulation parameters are within acceptable limits. *Raised intracranial pressure* - Centrineuraxial anesthesia can decrease spinal fluid pressure, potentially exacerbating a pressure gradient and leading to **brain herniation** in patients with raised intracranial pressure. - This is a serious and potentially fatal complication, making it a **strong contraindication**. *Platelets <80,000* - A platelet count below 80,000 cells/µL indicates significant **thrombocytopenia**, increasing the risk of bleeding. - Neuraxial anesthesia is generally regarded as **contraindicated** when platelet counts are below this threshold due to the heightened risk of spinal hematoma.

Q: Spinal anesthesia should be injected into the space between:

L3–L4. ***L3–L4*** - The **spinal cord** typically ends at the level of L1 or L2 in adults, making the L3–L4 interspace a safe region for injection. - Injecting at this level minimizes the risk of **direct spinal cord trauma** while allowing for effective drug delivery into the cerebrospinal fluid. *L5–S1* - While below the termination of the spinal cord, injection at L5-S1 is technically more challenging due to the **angle of the spinous processes** and depth of the interspace. - The wider interspinous space at L3-L4 generally makes it a more accessible and preferred site for spinal anesthesia. *T12–L1* - This interspace is above or at the typical **termination of the spinal cord**, making injection here carry a significant risk of **spinal cord injury**. - Direct trauma to the spinal cord can lead to severe neurological deficits. *L1–L2* - This interspace is at or very close to the **conus medullaris** (the end of the spinal cord) in most adults. - Injecting here poses a higher risk of **spinal cord damage** compared to lower lumbar interspaces, making it a less safe option.

Q: A 25 year old male with roadside accident underwent debridement and reduction of fractured both bones right forearm under axillary block. On the second postoperative day the patient complained of persistent numbness and paresthesia in the right forearm and the hand. The commonest cause of this neurological dysfunction could be all of the following except :

Systemic toxicity of local anaesthetics. ***Systemic toxicity of local anaesthetics*** - This typically presents with **acute neurological symptoms** (e.g., seizures, metallic taste, tinnitus) or **cardiovascular collapse** during or immediately after local anesthetic administration. - Persistent numbness and paresthesia on the second postoperative day are **not characteristic** of systemic local anesthetic toxicity, which is a transient effect. *Tourniquet pressure* - **Prolonged or excessively high tourniquet pressure** can lead to nerve ischemia and damage, causing paresthesia and numbness in the limb distal to the tourniquet. - These symptoms often persist for some time post-operatively, consistent with the patient's presentation. *Crush injury to the hand and lacerated nerves* - The initial **roadside accident** involving a severely injured limb could directly cause **nerve lacerations or crush injuries**, leading to immediate and persistent neurological deficits like numbness and paresthesia. - Such direct nerve trauma would manifest immediately and continue post-operatively, aligning with the patient's complaints. *A tight cast or dressing* - A **tight cast or dressing** applied to the forearm can compress nerves, leading to **ischemia and neuropathy**. - This mechanical compression can cause persistent numbness and paresthesia, which might become more noticeable as swelling increases post-surgery.

Q: All are management of PDPH except-

Stool softeners. ***Stool softeners*** - While **stool softeners** may be prescribed to prevent **straining** in patients experiencing PDPH, they do not directly treat the underlying cause or symptoms of PDPH. - The primary goal of PDPH management is to re-establish **CSF pressure** and relieve headache, which stool softeners do not achieve. *Analgesic + caffeine* - **Caffeine** is a common component of PDPH management as it causes **cerebral vasoconstriction**, which can help alleviate the headache. - **Analgesics** (e.g., NSAIDs, opioids) are used to manage the pain associated with PDPH. *Intravenous / oral fluids* - Increasing **fluid intake**, both oral and intravenous, helps to promote **CSF production** and potentially increase intracranial pressure, thereby alleviating PDPH symptoms. - This is a supportive measure for rehydration and to potentially restore **CSF volume**. *Upright position* - An **upright position** typically **worsens** PDPH symptoms because it increases the gravitational pull on the CSF, further lowering intracranial pressure. - Patients with PDPH are usually advised to maintain a **supine (flat)** position to minimize headache severity.

Q: Subarachnoid block as anaesthesia is contraindicated in –

Hemophilia. ***Hemophilia*** - Subarachnoid block, which involves puncturing the dura, is contraindicated in patients with **hemophilia** due to the high risk of **spinal hematoma**. - A spinal hematoma can lead to **cord compression** and devastating neurological deficits. *Atherosclerotic gangrene* - This condition involves **peripheral vascular disease** and tissue necrosis, but does not inherently contraindicate subarachnoid block. - In fact, subarachnoid block can be beneficial by providing **sympathectomy**, improving blood flow to the affected limb. *Diabetic gangrene* - Similar to atherosclerotic gangrene, **diabetic gangrene** is a manifestation of peripheral vascular disease often complicated by neuropathy and infection. - There is no direct contraindication to subarachnoid block for this condition itself, provided there are no concurrent coagulopathies or active infections at the needle insertion site. *Buerger's disease* - **Buerger's disease** (thromboangiitis obliterans) is an inflammatory vasculitis of small and medium-sized arteries and veins, primarily in the limbs. - Subarachnoid block may even be indicated to improve blood flow by inducing **sympathectomy**, helping relieve ischemic pain or prevent further tissue damage.

Question 1

Spinal anesthesia is given at which of the following levels?

Accepted Answer

L2-4

Answer

Below L5 (caudal)

Answer

L1-2

Answer

Midline of thorax

Question 2

Which of the following is not a contraindication for neuraxial block?

Accepted Answer

Patient on antihypertensive medication

Answer

Patient on clopidogrel

Answer

Local infection

Answer

Platelet count < 50,000

Question 3

Which is not true about spinal anesthesia?

Accepted Answer

Produces complete sensory and motor paralysis below the level

Answer

Useful for lower limb surgery

Answer

It produces more hemodynamic alteration than epidural anesthesia

Answer

Autonomic fibers are affected above the sensory level

Question 4

Most common injection site infection in spinal anaesthesia

Accepted Answer

Staphylococcus

Answer

Bacteroides

Answer

Pseudomonas

Answer

Streptococcus

Question 5

The site of action of local anaesthetic in epidural anesthesia is

Accepted Answer

Spinal nerve root

Answer

Anterior root of spinal nerve

Answer

Epidural neural tissue

Answer

Spinal cord

Question 6

Centrineuraxial anaesthesia is not contraindicated in:

Accepted Answer

Patient on aspirin

Answer

Patient on anticoagulants

Answer

Raised intracranial pressure

Answer

Platelets <80,000

Question 7

Spinal anesthesia should be injected into the space between:

Accepted Answer

L3–L4

Answer

L5–S1

Answer

T12–L1

Answer

L1–L2

Question 8

A 25 year old male with roadside accident underwent debridement and reduction of fractured both bones right forearm under axillary block. On the second postoperative day the patient complained of persistent numbness and paresthesia in the right forearm and the hand. The commonest cause of this neurological dysfunction could be all of the following except :

Accepted Answer

Systemic toxicity of local anaesthetics

Answer

Tourniquet pressure

Answer

Crush injury to the hand and lacerated nerves

Answer

A tight cast or dressing

Question 9

All are management of PDPH except-

Accepted Answer

Stool softeners

Answer

Analgesic + caffeine

Answer

Intravenous / oral fluids

Answer

Upright position

Question 10

Subarachnoid block as anaesthesia is contraindicated in –

Accepted Answer

Hemophilia

Answer

Atherosclerotic gangrene

Answer

Diabetic gangrene

Answer

Buerger's disease

Regional Anesthesia — MCQs

Regional Anesthesia — MCQs

On this page

Practice by Chapter

Want unlimited practice?