Anesthesiology
7 questionsWhich drug is commonly used for emergency intubation?
Which of the following statements is NOT true regarding rapid induction of anesthesia?
Which anaesthetic is contraindicated in renal failure?
What is a significant disadvantage of ketamine?
Intraocular pressure is increased by which anaesthetic?
Which of the following anesthetic agents is most notable for its analgesic properties?
Dissociative anaesthesia is produced by?
NEET-PG 2013 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1271: Which drug is commonly used for emergency intubation?
- A. None of the options
- B. Etomidate (Correct Answer)
- C. Propofol
- D. Ketamine
Explanation: ***Etomidate*** - Etomidate is a **short-acting nonbenzodiazepine hypnotic** often preferred for rapid sequence intubation (RSI) due to its minimal impact on **hemodynamic stability**. - It induces **rapid unconsciousness** with a quick onset and offset, making it suitable for emergency airway management in patients who are hemodynamically compromised. *Propofol* - Propofol is a **potent intravenous anesthetic** that can cause significant **hypotension** due to vasodilation and myocardial depression. - While it provides rapid onset of sedation and amnesia, its cardiovascular side effects make it less ideal for patients with **unstable hemodynamics** during emergency intubation. *Ketamine* - Ketamine is a **dissociative anesthetic** that causes a cataleptic state, amnesia, and analgesia, often leading to **bronchodilation** and cardiovascular stimulation. - While useful in patients with **reactive airway disease** or hypotension, it can increase intracranial pressure and may induce sympathetic stimulation, which might not be ideal for all emergency intubation scenarios. *None of the options* - This option is incorrect because **Etomidate is a commonly used drug** for emergency intubation, particularly where hemodynamic stability is a concern. - Other agents are also used but Etomidate is a clear clinical choice in many situations.
Question 1272: Which of the following statements is NOT true regarding rapid induction of anesthesia?
- A. Suxamethonium is often used.
- B. Mechanical ventilation is typically avoided before intubation.
- C. Pre-oxygenation is mandatory
- D. Sellick's maneuver is always required. (Correct Answer)
Explanation: ***Sellick's maneuver is always required.*** - **Sellick's maneuver**, or cricoid pressure, is applied to compress the esophagus against the vertebrae, aiming to prevent **gastric regurgitation** and aspiration during rapid sequence intubation (RSI). - While historically considered a standard component of RSI, its routine use has been increasingly questioned due to a lack of strong evidence supporting its efficacy and potential to impede glottic visualization and intubation. It is not "always" required; its application is often at the discretion of the anesthetist based on patient factors and risk assessment. *Pre-oxygenation is mandatory* - **Pre-oxygenation** is a critical step in rapid sequence induction, involving administering 100% oxygen for several minutes prior to induction. - This denitrogenates the functional residual capacity (FRC), creating an oxygen reservoir that extends the safe apnea time, thus preventing **hypoxemia** during the intubation attempt. *Suxamethonium is often used.* - **Suxamethonium** (succinylcholine) is a depolarizing neuromuscular blocker primarily used in rapid sequence intubation due to its **ultra-rapid onset** (30-60 seconds) and short duration of action (5-10 minutes). - Its rapid action facilitates quick muscle relaxation for tracheal intubation, which is crucial for minimizing the risk of aspiration in patients with a full stomach or other risk factors. *Mechanical ventilation is typically avoided before intubation.* - During rapid sequence induction, **positive pressure ventilation** with a bag-valve mask is typically avoided before intubation to prevent gastric insufflation. - Gastric insufflation can increase the risk of **regurgitation** and pulmonary aspiration of gastric contents, which is a major concern in patients undergoing RSI.
Question 1273: Which anaesthetic is contraindicated in renal failure?
- A. Isoflurane
- B. Desflurane
- C. Halothane
- D. Methoxyflurane (Correct Answer)
Explanation: ***Methoxyflurane*** - Methoxyflurane undergoes significant **metabolism** to produce inorganic **fluoride ions**, which are directly **nephrotoxic**. - This nephrotoxicity can cause **high-output renal failure** with reduced concentrating ability, making it contraindicated in patients with pre-existing renal impairment. *Isoflurane* - Isoflurane is minimally metabolized and produces very low levels of **fluoride ions**, making it generally **safe** for use in patients with renal failure. - Its elimination is primarily via the **lungs**, with very little hepatic metabolism or renal excretion of active compounds. *Desflurane* - Desflurane is also minimally metabolized, similar to isoflurane, and therefore produces negligible amounts of **fluoride ions**. - It is considered a **safe option** for patients with renal impairment due to its predominantly pulmonary elimination and lack of nephrotoxic metabolites. *Halothane* - While halothane can cause **hepatotoxicity**, it is generally **not directly nephrotoxic** in the way methoxyflurane is. - Its metabolism, though more extensive than isoflurane or desflurane, does not produce clinically significant levels of nephrotoxic fluoride ions to contraindicate its use in renal failure.
Question 1274: What is a significant disadvantage of ketamine?
- A. Increased heart rate
- B. Increased ICT
- C. Delirium (Correct Answer)
- D. All of the options
Explanation: ***Delirium*** - Ketamine is known to cause **emergence phenomena**, which include **vivid dreams, hallucinations**, and **delirium**, particularly during recovery from anesthesia. - This psychotomimetic effect can be distressing for patients and may necessitate the co-administration of a **benzodiazepine** to mitigate these symptoms. *Increased heart rate* - While ketamine does cause an **increase in heart rate** and **blood pressure** due to sympathetic stimulation, this is often considered a disadvantage but not the *most significant* when compared to the unique cognitive side effects. - This effect can be beneficial in patients with **hemodynamic instability**, but can be problematic in those with **cardiovascular disease**. *Increased ICT* - It is often considered a contraindication in patients with **elevated intracranial pressure (ICP)** as it can potentially increase **cerebral blood flow** and thus ICP. - However, recent studies suggest that in adequately ventilated patients, the effect on ICP may be less pronounced than previously thought, making delirium a more consistent and prominent disadvantage for many patients. *All of the options* - While ketamine can cause an **increased heart rate** and potentially affect **intracranial pressure**, **delirium** and other emergence phenomena are often highlighted as a unique and significant disadvantage because they are highly distressing and difficult to manage. - The psychotomimetic effects are a hallmark side effect that often governs its cautious use without concurrent medication.
Question 1275: Intraocular pressure is increased by which anaesthetic?
- A. Ketamine (Correct Answer)
- B. Nitrous Oxide
- C. Isoflurane
- D. Propofol
Explanation: ***Ketamine*** - **Ketamine** is known to increase **intraocular pressure (IOP)**, making it generally avoided in patients with glaucoma or penetrating eye injuries. - This effect is thought to be due to its dissociative properties, causing **nystagmus**, and stimulating extraocular muscles. *Nitrous Oxide* - **Nitrous oxide** by itself has minimal or no direct effect on **intraocular pressure (IOP)**. - However, in cases of an air-filled globe (e.g., after retinal detachment surgery), it can increase IOP by expanding the gas bubble. *Isoflurane* - **Isoflurane**, like most volatile anesthetics, typically **decreases intraocular pressure (IOP)**. - This reduction is generally due to its effects on reducing aqueous humor production and increasing uveoscleral outflow. *Propofol* - **Propofol** is known for its ability to **decrease intraocular pressure (IOP)**. - This effect is mediated by a reduction in aqueous humor production and an increase in uveoscleral outflow, making it a favorable choice in ophthalmic surgery.
Question 1276: Which of the following anesthetic agents is most notable for its analgesic properties?
- A. Ketamine (Correct Answer)
- B. Thiopentone
- C. Propofol
- D. None of the options
Explanation: ***Ketamine*** - **Ketamine** is unique among general anesthetics for its significant **analgesic properties**, which stem from its action as an **NMDA receptor antagonist**. - Its ability to provide pain relief makes it useful in scenarios where both **anesthesia** and **analgesia** are desired, such as for painful procedures or in trauma settings. *Propofol* - While **propofol** is a widely used intravenous anesthetic, it lacks intrinsic **analgesic properties**. Its primary effects are **sedation** and **hypnosis**. - Pain during propofol injection is common, and other analgesics are usually co-administered for painful procedures. *Thiopentone* - **Thiopentone** is an ultrashort-acting barbiturate primarily used for **induction of anesthesia** due to its rapid onset and profound hypnotic effects. - It has **no analgesic properties** and can even lower the pain threshold, requiring concurrent administration of analgesics.
Question 1277: Dissociative anaesthesia is produced by?
- A. Ketamine (Correct Answer)
- B. Etomidate
- C. Propofol
- D. Thiopentone
Explanation: ***Ketamine*** - **Ketamine** is a unique anesthetic that produces a state of **dissociative anesthesia**, characterized by a trance-like state, analgesia, amnesia, and catalepsy. - This effect is primarily due to its antagonism of the **N-methyl-D-aspartate (NMDA) receptor**. *Etomidate* - **Etomidate** is an intravenous anesthetic characterized by its **cardiovascular stability**, making it suitable for patients with heart conditions. - It works primarily by modulating **GABA-A receptors** but does not produce dissociative anesthesia. *Propofol* - **Propofol** is a widely used intravenous anesthetic known for its **rapid onset and recovery**, and it is often used for induction and maintenance of general anesthesia. - Its primary mechanism of action involves enhancing the effects of **GABA-A receptors**, leading to central nervous system depression, but not dissociative anesthesia. *Thiopentone* - **Thiopentone** (Thiopental) is a barbiturate anesthetic that causes rapid loss of consciousness and has been historically used for inducing general anesthesia. - It acts as a **GABA-A receptor agonist**, depressing the central nervous system, but it does not produce the distinct dissociative state seen with ketamine.
Orthopaedics
2 questionsMost common nerve injured in fracture of medial epicondyle of humerus is:
Bulge sign in the knee joint is seen after how much fluid accumulation?
NEET-PG 2013 - Orthopaedics NEET-PG Practice Questions and MCQs
Question 1271: Most common nerve injured in fracture of medial epicondyle of humerus is:
- A. Radial nerve
- B. Ulnar nerve (Correct Answer)
- C. Median nerve
- D. Musculocutaneous nerve
Explanation: ***Ulnar nerve*** - The **ulnar nerve** runs directly behind the **medial epicondyle** of the humerus in a groove called the **cubital tunnel**, making it highly vulnerable to injury during fractures of this bony prominence. - Injury to the ulnar nerve at this location can cause symptoms like **numbness and tingling** in the **little finger and half of the ring finger**, **weakness in certain hand muscles**, and eventually a **"claw hand" deformity**. *Radial nerve* - The **radial nerve** courses along the posterior aspect of the humerus in the **spiral groove** and is more commonly injured with **mid-shaft humeral fractures**. - Injury typically results in **wrist drop** and **sensory loss over the dorsum of the hand**. *Median nerve* - The **median nerve** travels more anteriorly in the arm and forearm and is most commonly injured with **supracondylar fractures of the humerus** or **carpal tunnel syndrome** at the wrist. - Damage leads to **ape hand deformity** and sensory deficits over the **thumb, index, middle, and radial half of the ring finger**. *Musculocutaneous nerve* - The **musculocutaneous nerve** innervates the biceps brachii and brachialis muscles and provides sensation to the lateral forearm; it is **less commonly injured in elbow fractures**. - Injury would primarily affect **elbow flexion** and **sensation over the lateral forearm**, which is not the typical presentation for medial epicondyle fractures.
Question 1272: Bulge sign in the knee joint is seen after how much fluid accumulation?
- A. 200 ml
- B. < 30 ml (Correct Answer)
- C. 100 ml
- D. 400 ml
Explanation: **< 30 ml** - The **bulge sign** is a sensitive test for detecting small amounts of **effusion** in the knee joint. - It is typically positive with as little as 4-8 mL to 10-30 mL of fluid, making "< 30 mL" the most appropriate answer. *100 ml* - An effusion of 100 mL is a **moderate to large amount** of fluid, which would typically elicit a positive **patellar tap test (ballottement)** rather than just a bulge sign. - The **bulge sign** is designed to detect much smaller effusions. *400 ml* - This represents a **very large effusion** that would be clinically obvious and cause significant swelling and discomfort, far exceeding the threshold for a simple bulge sign. - A knee with 400 mL of fluid would likely have a tense, bulging appearance and a very prominent **patellar tap**. *200 ml* - This is also a **significant effusion** that would easily be detected by a patellar tap test and would present with gross swelling. - The **bulge sign** is specifically for subtler fluid collections.
Radiology
1 questionsRadiological sign in case of Perthes disease?
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 1271: Radiological sign in case of Perthes disease?
- A. Flattening of femoral head (Correct Answer)
- B. Fragmentation of femoral head epiphysis
- C. Lateral femoral head displacement
- D. Limited hip abduction
Explanation: ***Flattening of femoral head*** - **Flattening** and **fragmentation** of the femoral head are characteristic radiological findings in **early-stage** Perthes disease. - This flattening is a direct consequence of the **avascular necrosis** and subsequent **remodeling** of the femoral epiphysis. *Fragmentation of femoral head epiphysis* - While **fragmentation** is a key feature of Perthes disease, it's typically observed **after** the initial flattening and sclerosis in the avascular stage. - It represents the process of **resorption** and **revascularization** as the bone attempts to heal. *Lateral femoral head displacement* - **Lateral displacement** of the femoral head is a more common finding in conditions like **slipped capital femoral epiphysis (SCFE)**, where the epiphysis slips from the metaphysis. - In Perthes disease, the primary issue is the **necrosis and collapse** of the femoral head itself, rather than displacement from the neck. *Limited hip abduction* - **Limited hip abduction** is a clinical sign, not a radiological sign, and it is a common symptom in Perthes disease due to pain, inflammation, and deformity of the femoral head. - Radiological signs are visual abnormalities observed on imaging studies like X-rays.