Regional Anesthesia Practice Questions

Q: Which of the following statements about post-dural puncture headache is incorrect?

The timing of ambulation has no effect on its incidence.. ***The timing of ambulation has no effect on its incidence.*** - This statement is **incorrect** because while previously thought to reduce the incidence, early ambulation does not significantly alter the risk of developing a **post-dural puncture headache (PDPH)**. - However, the absence of an effect on incidence does not mean that ambulation is completely irrelevant; it has been shown to cause more intense pain related to the headache when occurring in some individuals. *A thin bore needle is less likely to cause it.* - This statement is **correct**. Using a **smaller gauge (thin bore) needle** causes a smaller dural tear, which reduces the leakage of cerebrospinal fluid and thus lowers the risk of PDPH. - The size of the needle is a primary determinant of the incidence of PDPH. *It is more common in females.* - This statement is **correct**. **Females**, particularly those who are pregnant or in the postpartum period, have a higher incidence of PDPH compared to males. - Hormonal factors and differences in dural elasticity are thought to contribute to this increased susceptibility. *Using a beveled edge needle parallel to the long axis of the spine can help prevent it.* - This statement is **correct**. Inserting a **beveled needle parallel** to the longitudinal dural fibers spreads them apart rather than cutting across them, which can reduce the size of the dural tear. - This technique minimizes cerebrospinal fluid leakage and, consequently, the risk of PDPH.

Q: Where is the drug injected during epidural anaesthesia?

Outside the dura. ***Outside the dura*** - Epidural anaesthesia involves injecting the drug into the **epidural space**, which is located **outside the dura mater**. - This space contains fat, connective tissue, and blood vessels, allowing the anaesthetic to diffuse to the spinal nerves. *Inside the duramater* - Injecting inside the dura mater would place the drug into the **subdural space**, which is not the target for epidural anaesthesia. - This approach is associated with a higher risk of complications and is not the intended site for an epidural block. *Inside arachnoidmater* - The arachnoid mater is a middle layer of the meninges; injecting here is not the standard for epidural anaesthesia. - This would typically involve puncturing both the dura and arachnoid, potentially leading to a **spinal block** rather than an epidural. *Inside piamater* - The pia mater is the innermost meningeal layer, directly covering the spinal cord; injection here would be intrathecal. - This site is reserved for **spinal anaesthesia** (subarachnoid block) and carries different physiological effects and risks compared to epidural anaesthesia.

Q: What is a contraindication to performing a neuraxial block?

Clotting disorders. ***Clotting disorders*** - **Coagulopathy** or **anticoagulation** significantly increases the risk of **epidural hematoma**, which can lead to spinal cord compression and permanent neurological damage. - The procedure involves puncturing blood vessels, and impaired clotting could result in uncontrolled bleeding into the epidural or intrathecal space. *Hypertension* - While careful management of blood pressure is needed before and during a neuraxial block, **controlled hypertension** is not an absolute contraindication. - Severe or uncontrolled hypertension may be a concern due to increased risk of hemodynamic instability but doesn't preclude the procedure itself. *Renal disease* - **Chronic renal disease** itself is not a direct contraindication, though it might impact drug clearance if local anesthetics are used in large doses. - However, severe renal disease can be associated with coagulopathies, which would then become the primary contraindication. *Diabetes* - **Diabetes mellitus** is generally not a contraindication to neuraxial blocks. - Careful monitoring of blood glucose is necessary, but the condition itself does not increase the specific risks associated with the procedure.

Q: Post dural puncture headache usually presents within ?

12-72 Hrs. ***12-72 Hrs*** - The onset of a **post-dural puncture headache (PDPH)** typically occurs within **12 to 72 hours** after the dural puncture. - This delay is thought to be related to the time it takes for significant **cerebrospinal fluid (CSF) leakage** and corresponding intracranial hypotension to develop. *0-6 Hrs* - Headaches presenting within this timeframe are less likely to be true **PDPH** as the typical latency period for significant CSF leakage and its symptomatic effects hasn't usually manifested. - Such early headaches might be due to other causes like **anxiety**, **dehydration**, or mild irritation from the procedure. *6-12 Hrs* - While possible, onset within this timeframe is less common than the 12-72 hour window for **classic PDPH**. - Moderate **CSF leakage** might lead to symptoms in some individuals, but the vast majority present later. *72-96 Hrs* - Although PDPH can persist for days or even weeks, its **onset** is significantly less common in this range. - A headache beginning this late may prompt consideration of other differential diagnoses, though late-onset PDPH is not unheard of.

Q: Drug of choice for Bier's block ?

Lidocaine. ***Lidocaine*** - **Lidocaine** is the preferred local anesthetic for **Bier's block** (intravenous regional anesthesia) due to its rapid onset and good safety profile. - Its relatively short duration of action and **minimal cardiotoxicity** upon systemic release are favorable for this technique. *Bupivacaine* - **Bupivacaine** has a **longer duration of action** and is associated with a higher risk of **cardiotoxicity** when inadvertently delivered systemically, making it less suitable for Bier's block. - Its use in Bier's block is generally avoided due to the potential for significant adverse events if the tourniquet malfunctions or is released prematurely. *Etidocaine* - **Etidocaine** is a potent, **long-acting local anesthetic** with a similar toxicity profile to bupivacaine, making it less ideal for Bier's block. - Its prolonged action and higher potential for systemic toxicity make it less favorable for a procedure where rapid washout and lower systemic risk are desired. *Ropivacaine* - **Ropivacaine** is an amide-type local anesthetic with a similar efficacy to bupivacaine but with a **lower potential for cardiotoxicity**. - While safer than bupivacaine, **lidocaine** is still generally preferred for Bier's block due to its established safety record, faster onset, and lower cost.

Q: Which of the following cannot be given by epidural anaesthesia?

Remifentanil. ***Remifentanil*** - **Remifentanil** is specifically designed for **intravenous administration** and is rapidly metabolized by plasma esterases, making it unsuitable for epidural use. - Due to its short half-life and rapid metabolism, epidural administration would provide inconsistent and fleeting analgesia, and its breakdown products are not inert in the epidural space, potentially causing **neurotoxicity**. *Morphine* - **Morphine** is a commonly used opioid for **epidural analgesia** due to its hydrophilicity, allowing for prolonged action in the cerebrospinal fluid. - It provides effective **postoperative pain relief** and has a relatively slow onset but long duration of action when administered epidurally. *Alfentanil* - **Alfentanil** is a synthetic opioid that has been used for **epidural analgesia**, though less commonly than fentanyl or sufentanil, sometimes in conjunction with local anesthetics. - It has a faster onset and shorter duration of action compared to morphine, but still provides effective **analgesia** when administered epidurally. *Fentanyl* - **Fentanyl** is a widely used lipophilic opioid for **epidural analgesia**, often combined with local anesthetics, for both surgical and obstetric pain. - Its lipophilicity allows for rapid absorption and a relatively quick onset of action, providing effective **segmental analgesia**.

Q: Which of the following is NOT a contraindication for spinal anaesthesia?

Hypertension. ***Hypertension*** - While **severe uncontrolled hypertension** may necessitate blood pressure stabilization before surgery, **mild to moderate hypertension** is not an absolute contraindication for spinal anesthesia. - In fact, spinal anesthesia can sometimes be beneficial in hypertensive patients due to its **vasodilatory effects**, which may help lower blood pressure. *Bleeding disorder* - A **bleeding disorder** (e.g., thrombocytopenia, coagulopathy) is a **major contraindication** due to the high risk of **epidural or spinal hematoma** formation. - A hematoma can lead to **spinal cord compression** and irreversible neurological damage. *Raised intracranial tension* - **Raised intracranial tension (ICT)** is a **strict contraindication** because the drop in cerebrospinal fluid (CSF) pressure during spinal anesthesia can worsen the pressure gradient across the foramen magnum. - This can precipitate **herniation of the brainstem** and lead to catastrophic neurological injury or death. *Infection at injection site* - The presence of an **infection at the injection site** is an absolute contraindication as it poses a significant risk of introducing bacteria into the **subarachnoid space**. - This can lead to serious complications such as **meningitis** or a **spinal abscess**.

Q: What clinical sign is used to confirm the success of an epidural block?

Loss of sensation in the T10 dermatome. ***Loss of sensation in the T10 dermatome*** - The **T10 dermatome** is a common and reliable landmark for assessing the spread and effectiveness of an epidural block, especially for surgical procedures or labor analgesia impacting the abdominal and pelvic regions. - A successful epidural block should produce a **bilateral, symmetric sensory deficit** to pinprick or cold sensation within the target dermatomes, indicating proper anesthetic distribution. *Inability to dorsiflex the foot* - This symptom suggests a motor block primarily affecting the **deep peroneal nerve** (L4-L5 nerve roots), which would be a sign of a dense spinal block rather than a typical epidural, or an overly extensive epidural block, especially if it's bilateral. - While some motor weakness is expected with an epidural block, a complete inability to dorsiflex the foot is not the primary or most sensitive indicator of its success for general pain relief. *Loss of resistance (used during block placement)* - **Loss of resistance** is a technique used *during the placement* of an epidural needle to identify the epidural space (passing through the ligamentum flavum). - It is a procedural step for correct needle positioning, not a clinical sign used *after* injection to confirm the block's effect. *Westphal's sign (diminished patellar reflex)* - **Westphal's sign** refers to the absence or diminution of the patellar reflex (an L2-L4 reflex), which can indicate a neurological issue involving the quadriceps muscles or the femoral nerve pathway. - While a dense epidural block can affect motor function and reflexes, Westphal's sign is not typically used as the primary or most accurate indicator of a successful epidural block's sensory coverage.

Q: Epidural narcotics are preferred over epidural local anesthetics because they cause –

No motor paralysis. **No motor paralysis** - Epidural narcotics (opioids) provide **analgesia** by binding to opioid receptors in the spinal cord, primarily affecting pain sensation pathways. - This selective action allows for pain relief without significantly impacting **motor nerve fibers**, thus avoiding motor paralysis. *Less respiratory depression* - While epidural opioids can cause less systemic respiratory depression compared to intravenous administration, they still carry a **risk of respiratory depression**, especially with higher doses or inadequate monitoring. - This is not a primary reason for preference over local anesthetics, as local anesthetics at appropriate doses have a different mechanism and profile regarding respiratory effects. *Less dose is required* - The dose comparison depends on the specific drug and desired effect; however, the primary advantage of epidural narcotics over local anesthetics is not necessarily that a "lesser" dose is required for a therapeutic effect. - Local anesthetics require higher doses to achieve complete **sensory and motor blockade**, whereas opioids provide targeted analgesia at lower doses. *No retention of urine* - Epidural opioids are known to cause **urinary retention** as a common side effect due to their action on sacral parasympathetic outflow. - This is a significant disadvantage, unlike epidural local anesthetics, which can also cause urinary retention but through a different mechanism (motor block of the bladder).

Q: Most common post-operative complication of spinal anesthesia?

Hypotension due to spinal anesthesia. ***Hypotension due to spinal anesthesia*** - **Hypotension** is the **most common** immediate complication of spinal anesthesia due to **sympathetic blockade**, leading to **vasodilation** and decreased venous return. - This effect is often dose-dependent and can be managed with fluids and vasopressors if clinically significant. *Post-dural puncture headache* - While a notable complication, a **post-dural puncture headache (PDPH)** is less common than hypotension, occurring in a smaller percentage of spinal anesthesia cases. - PDPH results from persistent leakage of **cerebrospinal fluid** through the dural puncture site, leading to intracranial hypotension. *Urinary retention post-anesthesia* - **Urinary retention** is a relatively common complication after spinal anesthesia, but it is typically not as immediate or frequent as hypotension. - It occurs due to the **blockade of sacral parasympathetic nerves** that control bladder function, requiring temporary catheterization in some cases. *Infection leading to meningitis* - **Meningitis** is a **rare but severe** complication of spinal anesthesia, usually resulting from inadequate aseptic technique during the procedure. - Its incidence is very low compared to hemodynamic changes or even PDPH.

Question 1

Which of the following statements about post-dural puncture headache is incorrect?

Accepted Answer

The timing of ambulation has no effect on its incidence.

Answer

A thin bore needle is less likely to cause it.

Answer

It is more common in females.

Answer

Using a beveled edge needle parallel to the long axis of the spine can help prevent it.

Question 2

Where is the drug injected during epidural anaesthesia?

Accepted Answer

Outside the dura

Answer

Inside the duramater

Answer

Inside arachnoidmater

Answer

Inside piamater

Question 3

What is a contraindication to performing a neuraxial block?

Accepted Answer

Clotting disorders

Answer

Renal disease

Answer

Hypertension

Answer

Diabetes

Question 4

Post dural puncture headache usually presents within ?

Accepted Answer

12-72 Hrs

Answer

0-6 Hrs

Answer

6-12 Hrs

Answer

72-96 Hrs

Question 5

Drug of choice for Bier's block ?

Accepted Answer

Lidocaine

Answer

Bupivacaine

Answer

Etidocaine

Answer

Ropivacaine

Question 6

Which of the following cannot be given by epidural anaesthesia?

Accepted Answer

Remifentanil

Answer

Morphine

Answer

Alfentanil

Answer

Fentanyl

Question 7

Which of the following is NOT a contraindication for spinal anaesthesia?

Accepted Answer

Hypertension

Answer

Raised intracranial tension

Answer

Bleeding disorder

Answer

Infection at injection site

Question 8

What clinical sign is used to confirm the success of an epidural block?

Accepted Answer

Loss of sensation in the T10 dermatome

Answer

Inability to dorsiflex the foot

Answer

Loss of resistance (used during block placement)

Answer

Westphal's sign (diminished patellar reflex)

Question 9

Epidural narcotics are preferred over epidural local anesthetics because they cause –

Accepted Answer

No motor paralysis

Answer

Less respiratory depression

Answer

Less dose is required

Answer

No retention of urine

Question 10

Most common post-operative complication of spinal anesthesia?

Accepted Answer

Hypotension due to spinal anesthesia

Answer

Post-dural puncture headache

Answer

Urinary retention post-anesthesia

Answer

Infection leading to meningitis

Regional Anesthesia — MCQs

Regional Anesthesia — MCQs

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