NEET-PG 2013 - Anesthesiology Practice Questions

Q: The best local anesthetic for prolonged ophthalmic surgery requiring extended post-operative analgesia is:

Bupivacaine. ***Bupivacaine*** - **Bupivacaine** is an amide-type local anesthetic known for its **long duration of action** due to its high protein binding and lipid solubility. - This property makes it ideal for procedures requiring **prolonged analgesia**, such as extended ophthalmic surgery and post-operative pain control. *Tetracaine* - **Tetracaine** is an ester-type local anesthetic primarily used for **topical anesthesia**, especially in ophthalmology. - While effective for surface anesthesia, its duration of action is relatively short, making it unsuitable for prolonged surgical procedures requiring sustained nerve block. *Procaine* - **Procaine** is an ester-type local anesthetic with a **short duration of action** and is generally associated with a higher incidence of allergic reactions. - It is rarely used today for major regional blocks due to its limited potency and short effect, unlike the requirement for prolonged ophthalmic surgery. *Prilocaine* - **Prilocaine** is an amide-type local anesthetic with an **intermediate duration of action**. - Its use is limited in some cases due to its potential to cause **methemoglobinemia** at higher doses, making it less suitable for applications requiring extensive or prolonged regional anesthesia compared to bupivacaine.

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: What is the definition of conscious sedation?

Sedation with ability to respond to verbal commands. ***Sedation with ability to respond to verbal commands*** - Conscious sedation involves a drug-induced depression of consciousness during which the patient **retains the ability to respond purposefully to verbal commands**. - This level of sedation ensures that the patient's **airway reflexes** and **ventilatory function** remain intact. *CNS depression with unconsciousness* - This describes **general anesthesia** or **deep sedation**, where the patient is unable to respond purposefully to verbal commands. - In such states, spontaneous ventilation may be **inadequate**, and **airway support** is often required. *Sedation with inability to respond to verbal commands* - This definition aligns with **deep sedation** or **general anesthesia**, where the patient's consciousness is significantly depressed. - At this level, patients may require assistance in maintaining a **patent airway** and adequate ventilation. *None of the options* - This option is incorrect because one of the provided definitions accurately describes conscious sedation. - The definition of conscious sedation is well-established in clinical practice, emphasizing the **preservation of responsiveness**.

Q: The inducing agent of choice in shock -

Ketamine. **Ketamine** * **Ketamine** is preferred in shock due to its sympathomimetic properties, which maintain or increase blood pressure and heart rate, thus preserving **cardiovascular stability**. * It also has minimal respiratory depression and bronchodilatory effects, making it safer for patients with compromised respiratory function. * The cardiovascular stimulating effects of ketamine helps maintain haemodynamic stability in shocked patients. It maintains cerebral autoregulation and perfusion of vital organs. *Isoflurane* * **Isoflurane** is an inhaled anesthetic that typically causes **dose-dependent myocardial depression** and **vasodilation**, which can worsen hypotension in a shock state. * It can significantly decrease systemic vascular resistance, thereby exacerbating the already compromised cardiovascular status of a shock patient. *Desflurane* * **Desflurane** is an inhaled anesthetic known for its rapid onset and offset but can cause a **significant increase in heart rate and blood pressure** upon rapid concentration changes, which may be detrimental in an unstable patient. * Like isoflurane, it also causes dose-dependent peripheral vasodilation and myocardial depression, which can worsen hypotension in patients in shock. *Thiopentone* * **Thiopentone** is a barbiturate that causes significant **myocardial depression** and **peripheral vasodilation**, leading to a substantial drop in blood pressure. * Its use in shock would further compromise cardiovascular stability and is generally contraindicated due to its potent hemodynamic depressant effects.

Question 1

The best local anesthetic for prolonged ophthalmic surgery requiring extended post-operative analgesia is:

Accepted Answer

Bupivacaine

Answer

Tetracaine

Answer

Procaine

Answer

Prilocaine

Question 2

Drug of choice for Bier's block ?

Accepted Answer

Lidocaine

Answer

Bupivacaine

Answer

Etidocaine

Answer

Ropivacaine

Question 3

What is the definition of conscious sedation?

Accepted Answer

Sedation with ability to respond to verbal commands

Answer

CNS depression with unconsciousness

Answer

Sedation with inability to respond to verbal commands

Answer

None of the options

Question 4

The inducing agent of choice in shock -

Accepted Answer

Ketamine

Answer

Isoflurane

Answer

Desflurane

Answer

Thiopentone

NEET-PG 2013 — Anesthesiology