Anesthesiology
2 questionsWhich of the following statements about Nitrous Oxide (N2O) is true?
Inhalational agent of choice for neurosurgery?
NEET-PG 2013 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1301: Which of the following statements about Nitrous Oxide (N2O) is true?
- A. Least potent inhalational anesthetic (Correct Answer)
- B. Lighter than air
- C. Effective muscle relaxant
- D. Does not cause diffusion hypoxia
Explanation: **Least potent inhalational anesthetic** - Nitrous oxide has a **high Minimum Alveolar Concentration (MAC)** of approximately 104%, making it the least potent of the commonly used inhalational anesthetics. - Its high MAC means a very high concentration is required to achieve surgical anesthesia, which is why it is typically used as an adjunct to more potent agents. *Lighter than air* - The molecular weight of nitrous oxide (N2O) is 44, which is **heavier than air** (average molecular weight approximately 29 g/mol). - Its density is greater than air, meaning it would tend to sink rather than rise. *Effective muscle relaxant* - Nitrous oxide provides **minimal to no skeletal muscle relaxation** benefits. - If muscle relaxation is required, a neuromuscular blocking agent must be administered separately. *Does not cause diffusion hypoxia* - Nitrous oxide rapidly diffuses out of the blood into the alveoli during emergence, diluting the oxygen and carbon dioxide there. - This rapid diffusion can lead to **diffusion hypoxia** (also known as the "second gas effect"), necessitating the administration of 100% oxygen during recovery to prevent this complication.
Question 1302: Inhalational agent of choice for neurosurgery?
- A. Halothane
- B. Enflurane
- C. Isoflurane (Correct Answer)
- D. N2O
Explanation: ***Isoflurane*** - **Isoflurane** is preferred in neurosurgery due to its minimal impact on **cerebral blood flow** and **intracranial pressure (ICP)**, allowing cerebral autoregulation to be largely preserved. - It maintains **cerebral perfusion pressure** well and has a relatively fast onset and offset, facilitating neurological assessment post-operatively. *Halothane* - **Halothane** significantly increases **cerebral blood flow** and **intracranial pressure (ICP)**, which is undesirable in neurosurgical patients. - Its slow elimination can prolong recovery and neurological assessment, making it unsuitable for neurosurgery. *Enflurane* - **Enflurane** can cause central nervous system excitation and has been associated with **seizure activity** at higher concentrations, making it contraindicated in neurosurgical procedures. - Like halothane, it can also increase **cerebral blood flow** and **intracranial pressure**. *N2O* - **Nitrous oxide (N2O)** should be avoided in neurosurgery, especially if there's a risk of **intracranial air** or **pneumocephalus**, as it can expand air-filled spaces and increase ICP. - It also has a weak anesthetic effect and is often combined with other agents, but its cerebral vasodilatory properties can still be problematic.
Dental
1 questionsTurn-buckle cast is used for ?
NEET-PG 2013 - Dental NEET-PG Practice Questions and MCQs
Question 1301: Turn-buckle cast is used for ?
- A. Fracture of the humerus
- B. Management of spinal deformities (Correct Answer)
- C. Fracture of the femur
- D. Cervical spine immobilization
Explanation: ***Management of spinal deformities*** - A **turn-buckle cast** is specifically designed to apply gradual, corrective forces for **spinal deformities** like scoliosis or kyphosis. - It allows for incremental adjustments to the cast to achieve progressive stretching and correction of the spinal curve. *Fracture of the humerus* - **Humerus fractures** are typically managed with hanging arm casts, coaptation splints, or surgical fixation, depending on the fracture type and location. - A turn-buckle cast is not suitable for immobilizing or reducing a **humeral fracture**. *Fracture of the femur* - **Femur fractures** in adults usually require surgical intervention, such as intramedullary nailing, due to the high biomechanical stress on the bone. - For conservative management in children, traction or spica casts might be used, but not a **turn-buckle cast**. *Cervical spine immobilization* - **Cervical spine immobilization** is typically achieved using rigid cervical collars, halo vests, or specialized orthoses designed to restrict head and neck movement. - A turn-buckle cast is too bulky and not anatomically suitable for effective **cervical spine stabilization**.
Internal Medicine
1 questionsWhich type of arthritis is characterized by the absence of a periosteal reaction?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1301: Which type of arthritis is characterized by the absence of a periosteal reaction?
- A. Psoriatic arthritis
- B. Neuropathic arthritis (Correct Answer)
- C. Rheumatoid arthritis
- D. Reactive arthritis
Explanation: ***Neuropathic arthritis*** - **Neuropathic arthritis** (**Charcot joint**) is characterized by progressive joint destruction due to loss of proprioception and pain sensation, leading to severe bone and joint damage without a typical **periosteal reaction**. - The absence of normal protective reflexes results in repetitive microtrauma, often leading to bone resorption and fragmentation rather than new bone formation (periosteal reaction). *Psoriatic arthritis* - **Psoriatic arthritis** often presents with distinctive **periosteal reactions**, particularly at entheses and along the shafts of small bones (e.g., "pencil-in-cup" deformities and fluffy periostitis) [1]. - These periosteal changes are a hallmark of the inflammatory process affecting bone and connective tissues in psoriatic arthritis. *Rheumatoid arthritis* - **Rheumatoid arthritis** primarily involves the synovium, leading to erosions rather than prominent periosteal reactions in early stages [1]. - While periostitis can occur in chronic, destructive rheumatoid arthritis, it is not a primary or characteristic finding compared to other inflammatory arthritides. *Reactive arthritis* - **Reactive arthritis** frequently causes **periosteal reactions**, particularly at entheses (where tendons and ligaments attach to bone) and along the shafts of long bones, often described as "fluffy" periostitis [1]. - These new bone formations are a key radiological feature distinguishing it from other types of inflammatory arthritis.
Orthopaedics
5 questionsWhat is the purpose of the Insall-Salvati index?
Which condition can lead to the formation of loose bodies in the joint?
Most common site of osteochondritis dissecans?
Windswept deformity is seen in which condition?
What is the generally recommended maximum weight for skeletal traction in adult patients?
NEET-PG 2013 - Orthopaedics NEET-PG Practice Questions and MCQs
Question 1301: What is the purpose of the Insall-Salvati index?
- A. To measure ankle dorsiflexion range
- B. To assess patellar height and tendon length ratio (Correct Answer)
- C. To evaluate elbow joint stability
- D. To assess wrist bone alignment
Explanation: ***To assess patellar height and tendon length ratio*** - The **Insall-Salvati index** is a radiographic measurement used to determine **patellar height** by comparing the length of the patellar tendon to the greatest diagonal length of the patella. - It helps in diagnosing conditions like **patella alta** (high-riding patella) or **patella baja** (low-riding patella), which can contribute to knee pain and instability. *To evaluate elbow joint stability* - **Elbow joint stability** is typically assessed through clinical examination for ligamentous integrity (e.g., UCL, RCL) and sometimes dynamic imaging, not by the Insall-Salvati index. - The Insall-Salvati index is specific to the **knee joint** and **patellar position**. *To measure ankle dorsiflexion range* - **Ankle dorsiflexion range** is measured clinically using a goniometer or in 3D motion analysis, not with the Insall-Salvati index. - This index is a specialized measurement for the **patellofemoral joint**. *To assess wrist bone alignment* - **Wrist bone alignment** is evaluated using various radiographic measurements such as the scaphoid-lunate angle or carpal height ratio. - The Insall-Salvati index has no application in the assessment of the **wrist**.
Question 1302: Which condition can lead to the formation of loose bodies in the joint?
- A. Rheumatoid arthritis
- B. Ankylosing spondylitis
- C. Osteoarthritis (Correct Answer)
- D. Systemic lupus erythematosus
Explanation: ***Osteoarthritis*** - In **osteoarthritis**, the **degenerative process** of cartilage can lead to fragments breaking off and floating within the joint space, forming **loose bodies**. - These loose bodies, also known as **joint mice**, can cause mechanical symptoms like locking, clicking, or catching in the joint. *Rheumatoid arthritis* - **Rheumatoid arthritis** is an **inflammatory autoimmune disease** primarily affecting the synovium. - While it can cause joint damage, it typically does not lead to the formation of cartilaginous or bony loose bodies. *Ankylosing spondylitis* - **Ankylosing spondylitis** is a **chronic inflammatory disease** primarily affecting the spine and sacroiliac joints. - Its hallmark is new bone formation and fusion of vertebrae, not the formation of loose bodies within the joint. *Systemic lupus erythematosus* - **Systemic lupus erythematosus (SLE)** is a systemic autoimmune disease that can affect multiple organs, including joints. - While it can cause **non-erosive arthritis**, it does not typically result in the formation of loose bodies.
Question 1303: Most common site of osteochondritis dissecans?
- A. Lateral part of the medial femoral condyle (Correct Answer)
- B. Medial part of the medial femoral condyle
- C. Lateral part of the lateral femoral condyle
- D. Medial part of the lateral femoral condyle
Explanation: ***Lateral part of the medial femoral condyle*** - This is the **most common site** for osteochondritis dissecans in the knee, accounting for about 85% of cases. - The condition involves a localized area of **osteonecrosis and subchondral bone separation** from the epiphysis, typically afflicting this specific load-bearing region. *Medial part of the medial femoral condyle* - This location is **less common** for osteochondritis dissecans compared to the lateral aspect of the medial femoral condyle. - While osteochondral lesions can occur on any part of the condyle, the specific biomechanical stresses make the lateral part more susceptible. *Lateral part of the lateral femoral condyle* - Osteochondritis dissecans is **rarely found** in this location. - The lateral femoral condyle is generally less involved in osteochondritis dissecans of the knee. *Medial part of the lateral femoral condyle* - This site is also an **uncommon location** for osteochondritis dissecans. - The disease has a strong predilection for the medial femoral condyle, particularly its lateral aspect.
Question 1304: Windswept deformity is seen in which condition?
- A. Hyperparathyroidism
- B. Scurvy
- C. Rheumatoid Arthritis
- D. Rickets (Correct Answer)
Explanation: ***Rickets*** - **Windswept deformity** is characterized by bilateral knee deformities where one knee is in **valgus** and the other is in **varus**. - This condition is caused by a deficiency in **vitamin D**, **calcium**, or **phosphate**, leading to improper bone mineralization and subsequent bone deformities. *Rheumatoid Arthritis* - Rheumatoid arthritis is a **chronic autoimmune inflammatory disease** primarily affecting the synovial joints. - While it can cause joint deformities, they typically involve symmetric joint swelling, pain, and stiffness, with characteristic deformities like **ulnar deviation** or **swan-neck deformities**, rather than windswept deformity. *Hyperparathyroidism* - Hyperparathyroidism leads to excessive production of **parathyroid hormone**, which causes increased bone resorption and elevated blood calcium levels. - It can result in bone fragility, **osteitis fibrosa cystica**, and kidney stones, but it does not cause specific windswept deformity. *Scurvy* - Scurvy results from a severe deficiency of **vitamin C**, which is essential for collagen synthesis. - It presents with symptoms like bleeding gums, poor wound healing, and perifollicular hemorrhages, but it does not typically cause windswept deformity of the knees.
Question 1305: What is the generally recommended maximum weight for skeletal traction in adult patients?
- A. 5 kg
- B. 10 kg
- C. 20 kg
- D. 15 kg (Correct Answer)
Explanation: ***15 kg*** - While the specific weight can vary based on the bone and patient, 10-15 kg is generally the **maximum recommended weight for skeletal traction** in adults to avoid complications. - Applying too much weight risks **damage to the bone, soft tissues, and nerves**, as well as potential pin site infections and neurovascular compromise. *5 kg* - This weight is typically more appropriate for **skin traction**, where the pulling force is applied externally to the skin, limiting the amount of weight that can be safely used without causing skin damage. - In skeletal traction, 5 kg is often used for **initial alignment or very tenuous fractures**, but it is generally insufficient for significant reduction or long-term stabilization. *10 kg* - 10 kg is a common starting point or moderate weight used in skeletal traction, particularly for **femur or tibia fractures**. - While often effective, it is not consistently the maximum safe weight, as some situations may allow or require slightly more weight up to 15 kg for optimal reduction. *20 kg* - Applying 20 kg of weight in skeletal traction is generally considered **excessive and dangerous** in most adult applications. - This high amount of weight significantly increases the risk of **pin loosening, osteomyelitis, neurovascular injury, and avascular necrosis**, especially in areas like the cervical spine or tibia.
Radiology
1 questionsWhich condition is associated with the pencil in cup deformity?
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 1301: Which condition is associated with the pencil in cup deformity?
- A. Rheumatoid arthritis
- B. Ankylosing spondylitis
- C. Avascular necrosis
- D. Psoriatic arthritis (Correct Answer)
Explanation: ***Psoriatic arthritis*** - The **pencil-in-cup deformity** is a classic radiographic finding in advanced psoriatic arthritis, occurring due to **periarticular bone erosion** and phalangeal telescoping. - This specific deformity is characterized by the proximal phalanx eroding and fitting into the expanded distal phalanx, resembling a "pencil in a cup." *Rheumatoid arthritis* - While rheumatoid arthritis causes significant joint destruction, it typically presents with **periarticular erosions** and **joint space narrowing**, but not the characteristic pencil-in-cup morphology. - Common deformities include **swan-neck** and **boutonnière** deformities, and ulnar deviation. *Ankylosing spondylitis* - This condition primarily affects the **axial skeleton**, leading to spinal fusion and **sacroiliitis**. - Peripheral joint involvement is less common and typically does not result in the pencil-in-cup deformity; instead, it can cause **syndesmophytes**. *Avascular necrosis* - **Avascular necrosis** (AVN) involves the death of bone tissue due to lack of blood supply, primarily affecting the femoral head or other major joints. - Radiographic findings include **subchondral collapse**, crescent sign, and eventual joint destruction, but not the specific deformities seen in inflammatory arthritis like pencil-in-cup.