Regional Anesthesia Practice Questions

Q: Following spinal subarachnoid block, a patient develops hypotension. Which of the following measures is NOT used for its management?

Lowering the head end. **Explanation:** Hypotension following spinal anesthesia is primarily caused by a **sympathetic blockade**, leading to venous pooling (decreased preload) and arterial vasodilation (decreased systemic vascular resistance). **Why "Lowering the head end" is the correct answer (NOT used):** While Trendelenburg (head-down) position was historically used to increase venous return, it is **avoided** immediately after a spinal block using hyperbaric local anesthetics. Lowering the head end can cause the anesthetic drug to spread cephalad (upward) due to gravity, potentially leading to a **"High Spinal"** or **"Total Spinal."** This can cause respiratory paralysis by blocking the phrenic nerve (C3-C5) and severe bradycardia by blocking cardioaccelerator fibers (T1-T4). **Analysis of other options:** * **Option B (Preloading):** Administering 500–1000 ml of crystalloids (like Ringer's Lactate) before the block expands intravascular volume to compensate for the impending vasodilation. * **Option C (Vasopressors):** Drugs like Phenylephrine or Methoxamine (alpha-1 agonists) cause vasoconstriction, directly counteracting the sympathetic block. * **Option D (Inotropes):** Dopamine or Ephedrine are used if hypotension is accompanied by bradycardia, as they provide both vasoconstriction and positive inotropic/chronotropic effects. **High-Yield Clinical Pearls for NEET-PG:** * **Level of Block:** Sympathetic denervation usually extends **2–3 segments higher** than the sensory block. * **Bezold-Jarisch Reflex:** Severe hypotension and bradycardia after spinal anesthesia can occur due to this reflex (triggered by low ventricular volume). * **Drug of Choice:** **Phenylephrine** is currently preferred for managing spinal-induced hypotension in obstetric patients as it maintains fetal pH better than ephedrine. * **Co-loading:** Administering fluids *at the same time* as the block is initiated is now considered more effective than pre-loading.

Q: Peribulbar injection is given in which space?

Periorbital space. **Explanation:** The correct answer is **C. Periorbital space**. In ophthalmic regional anesthesia, the goal is to deposit local anesthetic around the globe to achieve sensory block and akinesia. The **peribulbar block** involves injecting the anesthetic into the space **outside the muscle cone** (extraconal space) but within the orbit. This space is anatomically referred to as the **periorbital space**. The anesthetic then diffuses into the muscle cone and across the lids to provide the desired effect. **Analysis of Options:** * **A. Subtenon space:** This refers to the space between the Tenon’s capsule and the sclera. A Sub-Tenon block involves a blunt cannula injection directly into this potential space, providing rapid anesthesia with a lower risk of globe perforation. * **B. Muscle cone:** This is the target for a **Retrobulbar block**. In this technique, the needle penetrates the muscle cone (intraconal space) to deposit anesthetic near the ciliary nerves and ganglion. While effective, it carries a higher risk of optic nerve injury and brainstem anesthesia. * **D. Subperiorbital space:** This is a potential space between the periorbita (periosteum of the orbit) and the bony orbital wall, typically not the target for routine ophthalmic blocks. **High-Yield Clinical Pearls for NEET-PG:** * **Peribulbar vs. Retrobulbar:** Peribulbar is generally considered safer because the needle remains **extraconal**, reducing the risk of retrobulbar hemorrhage and optic nerve trauma. * **Volume:** Peribulbar blocks require a larger volume of anesthetic (6–10 mL) compared to retrobulbar blocks (2–4 mL). * **Hyaluronidase:** Often added to the local anesthetic mix to promote tissue diffusion, improving the success rate of the peribulbar block. * **Complication:** The most serious (though rare) complication of orbital blocks is **"Post-retrobulbar apnea syndrome"** due to accidental injection into the CNS via the optic nerve sheath.

Q: All of the following are absolute contraindications for neuraxial anesthesia, EXCEPT:

Bowel perforation. **Explanation:** Neuraxial anesthesia (Spinal/Epidural) involves blocking sympathetic outflow, leading to significant physiological changes. Understanding the distinction between absolute and relative contraindications is high-yield for NEET-PG. **Why Bowel Perforation is the Correct Answer:** Bowel perforation is **not** a contraindication for neuraxial anesthesia; in fact, it is often considered a **relative indication**. Spinal anesthesia causes a "contracted, quiet bowel" due to the blockade of sympathetic fibers (T5–L2) while leaving parasympathetic (vagal) tone unopposed. This improves surgical exposure and reduces the risk of aspiration compared to general anesthesia in a "full stomach" emergency. **Analysis of Incorrect Options (Absolute Contraindications):** * **Patient on Anticoagulants:** This is an absolute contraindication due to the high risk of **spinal/epidural hematoma**, which can lead to permanent neurological deficits or paraplegia. * **Fixed Output State:** Conditions like severe aortic or mitral stenosis are absolute contraindications. Neuraxial blocks cause peripheral vasodilation and a drop in systemic vascular resistance (SVR). Patients with fixed cardiac output cannot increase their stroke volume to compensate, leading to catastrophic hypotension and cardiac arrest. * **Hypovolemic Shock:** Severe hypovolemia is an absolute contraindication. The sympathetic blockade causes massive vasodilation, which, in the absence of adequate intravascular volume, leads to profound, irreversible circulatory collapse. **High-Yield Clinical Pearls:** * **Absolute Contraindications:** Patient refusal (most important), infection at the site, raised ICP (risk of herniation), and severe coagulopathy. * **Relative Contraindications:** Sepsis, neurological disorders (e.g., Multiple Sclerosis), and minor skeletal deformities. * **Sympathetic Blockade:** Usually extends 2–6 segments higher than the sensory block.

Q: All of the following are true regarding post-spinal headache, EXCEPT?

Associated with photophobia. **Explanation:** Post-Dural Puncture Headache (PDPH) is a common complication following spinal anesthesia or accidental dural puncture during epidural placement. **1. Why Option D is the Correct Answer (The Exception):** While PDPH is characterized by severe headache, it is **not typically associated with photophobia**. Photophobia is a hallmark of meningeal irritation (meningitis) or migraine. If a patient presents with photophobia, fever, and neck stiffness after spinal anesthesia, clinicians should prioritize ruling out **meningitis** rather than assuming PDPH. **2. Analysis of Incorrect Options:** * **Option A (Occurs within 48 hours):** This is true. PDPH typically manifests within 12 to 48 hours post-procedure. It rarely occurs immediately or after 5-7 days. * **Option B (Increased by sitting upright):** This is the **pathognomonic feature** of PDPH. It is a "postural headache" that worsens significantly when the patient sits or stands and is relieved by lying flat (supine). * **Option C (Due to CSF leak):** This is the underlying pathophysiology. Persistent leakage of CSF through the dural hole leads to **low intracranial pressure**. This causes traction on pain-sensitive intracranial structures (vessels and nerves) when the patient is upright. **High-Yield Clinical Pearls for NEET-PG:** * **Risk Factors:** Young age, female gender, pregnancy, and use of large-bore/cutting needles (e.g., Quincke). * **Prevention:** Use of small-gauge (25G-27G) and **non-cutting (pencil-point)** needles like **Sprotte or Whitacre**. * **Treatment:** Conservative management includes bed rest, hydration, and caffeine. The **Gold Standard** treatment for persistent PDPH is an **Epidural Blood Patch**.

Q: For which surgical area is a supraclavicular block indicated?

Arm. **Explanation:** The **supraclavicular block** is often referred to as the "spinal of the upper limb" because it provides dense, rapid-onset anesthesia for the entire arm. At the level of the supraclavicular fossa, the brachial plexus is most compact, consisting of three divisions. This anatomical arrangement allows for a reliable block of the **arm, elbow, forearm, and hand**. **Why the options are correct/incorrect:** * **Arm (Correct):** The supraclavicular approach targets the plexus where the divisions are tightly bundled, ensuring anesthesia of the musculocutaneous, radial, ulnar, and median nerves. It is the gold standard for surgeries involving the mid-humerus down to the hand. * **Shoulder (Incorrect):** While it can provide some coverage, the **interscalene block** is the preferred choice for shoulder surgery. The supraclavicular block often misses the suprascapular nerve and the cervical plexus branches (C3-C4) required for complete shoulder anesthesia. * **Neck (Incorrect):** The neck is supplied by the **cervical plexus**, not the brachial plexus. * **Forearm (Incorrect):** While the block *does* cover the forearm, the question asks for the primary surgical area indication. In NEET-PG contexts, if "Arm" is an option, it represents the most proximal extent of the block's reliable coverage compared to more distal blocks like the infraclavicular or axillary blocks. **High-Yield Clinical Pearls for NEET-PG:** 1. **Anatomy:** The plexus is located posterior and superior to the **subclavian artery**. 2. **Complications:** The most classic complication is **pneumothorax** (due to the proximity of the cupula of the lung). Other risks include Horner’s syndrome and phrenic nerve palsy (though less common than in interscalene blocks). 3. **Contraindication:** It should be avoided in patients with severe underlying lung disease (COPD) due to the risk of accidental phrenic nerve block or pneumothorax.

Question 1

In an ankle block, which of the following nerves is typically NOT blocked?

Accepted Answer

Common peroneal nerve

Answer

Superficial peroneal nerve

Answer

Deep peroneal nerve

Answer

Saphenous nerve

Question 2

What is the anesthesia modality of choice for a 65-year-old male patient with a history of coronary artery disease diagnosed with hemorrhoids undergoing hemorrhoidectomy?

Accepted Answer

Saddle anesthesia

Answer

Spinal anesthesia

Answer

General anesthesia

Answer

Caudal anesthesia

Question 3

Following spinal subarachnoid block, a patient develops hypotension. Which of the following measures is NOT used for its management?

Accepted Answer

Lowering the head end

Answer

Administration of 1000 ml of Ringer's lactate before the block

Answer

Administration of a vasopressor drug like methoxamine

Answer

Administration of an ionotrope like dopamine

Question 4

Peribulbar injection is given in which space?

Accepted Answer

Periorbital space

Answer

Subtenon space

Answer

Muscle cone

Answer

Subperiorbital space

Question 5

All of the following are absolute contraindications for neuraxial anesthesia, EXCEPT:

Accepted Answer

Bowel perforation

Answer

Patient on anticoagulants

Answer

Fixed output state

Answer

Hypovolemic shock

Question 6

All of the following are true regarding post-spinal headache, EXCEPT?

Accepted Answer

Associated with photophobia

Answer

Occurs within 48 hours

Answer

Increased by sitting upright

Answer

Due to cerebrospinal fluid (CSF) leak

Question 7

For which surgical area is a supraclavicular block indicated?

Accepted Answer

Arm

Answer

Shoulder

Answer

Neck

Answer

Forearm

Question 8

What is the most commonly used local anesthetic for intravenous regional anesthesia (Bier's block)?

Accepted Answer

Lignocaine

Answer

Bupivacaine

Answer

Prilocaine

Answer

Chloroprocaine

Question 9

A patient presents with trismus. Which of the following techniques will block the mylohyoid nerve, incisive nerve, and long buccal nerve?

Accepted Answer

Akinosi technique

Answer

Gow-Gates technique

Answer

V-block technique

Answer

Conventional inferior alveolar nerve block

Question 10

A 48-year-old male with triple vessel disease and longstanding diabetes developed gangrene in his left lower foot. Which is the best mode of anesthesia?

Accepted Answer

Popliteal block

Answer

Sciatic block

Answer

Femoral block

Answer

Saphenous nerve block

Regional Anesthesia — MCQs

Regional Anesthesia — MCQs

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