NEET-PG 2015 Practice Questions

Q: Laryngeal mask airway [LMA] is contraindicated in?

Pregnant female. ***Pregnant female*** - **Pregnant patients** are at an increased risk of **gastric reflux and aspiration pneumonitis** due to decreased lower esophageal sphincter tone and increased intra-abdominal pressure. - The LMA does not provide a secure airway seal against aspiration, making it contraindicated in cases where **aspiration risk is high**, such as pregnancy or full stomach. *Difficult airways* - The LMA is often considered a **rescue device** in difficult airway algorithms when tracheal intubation fails. - It can be used as a conduit for **fiberoptic intubation** or as a temporary airway while preparing for a definitive airway. *Ocular surgeries* - LMAs are generally suitable for ocular surgeries as they provide a stable airway without the use of a mask, which can obstruct the surgical field. - They tend to cause **less coughing and straining** upon insertion and maintenance compared to endotracheal tubes, which is beneficial in preventing increases in intraocular pressure. *In CPR* - The LMA can be an effective airway device during **cardiopulmonary resuscitation (CPR)** when endotracheal intubation is not immediately feasible. - It provides a relatively quick and easy way to establish an airway, facilitate ventilation, and reduce the risk of gastric insufflation during chest compressions.

Q: Which one of the following agents sensitizes the myocardium to catecholamines?

Halothane. ***Halothane*** - **Halothane** sensitizes the myocardium to the arrhythmogenic effects of **catecholamines**, leading to an increased risk of ventricular arrhythmias, especially in the presence of exogenous adrenaline. - This sensitization occurs due to its effect on myocardial **calcium ion** regulation and increased automaticity in cardiac pacemaker cells. *Isoflurane* - **Isoflurane** causes minimal sensitization of the myocardium to catecholamines compared to halothane. - It maintains **cardiac output** with a dose-dependent decrease in systemic vascular resistance. *Ether* - **Diethylether** historically caused sympathetic stimulation, which could mask some depressant effects but did not primarily sensitize the myocardium to arrhythmias from exogenous catecholamines. - Its use has largely been replaced due to its flammability and slower induction/recovery. *Propofol* - **Propofol** generally causes myocardial depression and vasodilation, but it does **not sensitize** the myocardium to catecholamines in a clinically significant way that increases arrhythmogenic risk. - It often leads to a decrease in **blood pressure** and heart rate.

Q: Which anesthetic agent is safe to use in patients with elevated intracranial pressure (ICP)?

Thiopentone. ***Thiopentone*** - **Thiopentone** is a barbiturate that **decreases cerebral blood flow** and **metabolic rate**, leading to a reduction in intracranial pressure (ICP). - Its rapid onset and short duration of action make it suitable for inducing anesthesia in patients with elevated ICP. *Halothane* - **Halothane** is a potent **vasodilator** that can increase cerebral blood flow and consequently **elevate intracranial pressure**, making it unsuitable. - It also has a **slow onset and offset**, which can be problematic in emergent situations involving ICP. *Ketamine* - **Ketamine** is known to significantly **increase cerebral blood flow** and **intracranial pressure**, making it generally contraindicated in patients with elevated ICP. - It can also cause **dissociative states** and **emergence delirium**, which can further complicate neurological assessment. *Ether* - **Ether** is an older anesthetic agent known to cause **significant cerebral vasodilation** and an **increase in intracranial pressure**. - It is **highly flammable** and rarely used in modern clinical practice due to its side effects and safety profile.

Q: At the end of anaesthesia after discontinuation of nitrous oxide and removal of endotracheal tube, 100% oxygen is administered to the patient to prevent:

Diffusion Hypoxia. ***Diffusion Hypoxia*** - Post-anaesthesia administration of 100% oxygen prevents **diffusion hypoxia**, a phenomenon where **nitrous oxide** rapidly diffuses out of the blood into the alveoli, diluting alveolar oxygen and carbon dioxide. - This rapid outflow of nitrous oxide can lead to a significant drop in **partial pressure of oxygen** in the alveoli, causing hypoxemia if not counteracted with high inspired oxygen. *Second gas effect* - The **second gas effect** refers to the phenomenon where the rapid uptake of a highly soluble anesthetic (like nitrous oxide) accelerates the uptake of a co-administered less soluble anesthetic. - This is an effect related to the **induction phase** of anesthesia, not emergence, and is distinct from the issues arising from nitrous oxide washout. *Bronchospasm* - **Bronchospasm** is an acute constriction of the bronchioles, often triggered by irritants, allergens, or certain medications. - While it can occur during emergence from anesthesia, it is not directly prevented by administering 100% oxygen and is typically managed with bronchodilators. *Hyperoxia* - **Hyperoxia** is a condition of excess oxygen in the body, which can be detrimental, but it is not the primary concern immediately following the discontinuation of nitrous oxide. - Administering 100% oxygen in this context is a **controlled, short-term measure** to prevent a more immediate and severe issue (hypoxia) rather than causing chronic hyperoxia.

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: Lift off test is done to assess the function of:

Subscapularis muscle function. ***Subscapularis muscle function*** - The **Lift-off test**, or Gerber's Lift-off test, specifically assesses the integrity and strength of the **subscapularis muscle** by evaluating its internal rotation and extension strength. - A positive test occurs when the patient is unable to lift their hand off their back, indicating a **subscapularis tear or weakness**. *Supraspinatus muscle function* - The **supraspinatus muscle** is primarily tested with the **empty can test** or full can test, which assess its role in shoulder abduction. - These tests evaluate for **impingement** or **tears** of the supraspinatus tendon. *Infraspinatus muscle function* - The **infraspinatus muscle** is mainly responsible for external rotation and is assessed using tests like the **resisted external rotation test** with the arm at the side. - This test is used to detect **infraspinatus tears** or weakness. *Teres Minor muscle function* - The **teres minor muscle** also contributes to external rotation of the shoulder, often tested in conjunction with the infraspinatus. - Its function can be isolated by testing resisted **external rotation** in 90 degrees of abduction and external rotation.

Q: The anterior humeral line and radiocapitellar alignment are most commonly disturbed in -

Supracondylar Fracture of the humerus. ***Supracondylar Fracture of the humerus*** - **Anterior humeral line** passes through the **anterior cortex of the humerus** and should intersect the middle third of the capitellum in a normal elbow. - In supracondylar fractures, particularly those with **posterior displacement**, this line is often displaced **anteriorly or posteriorly**, failing to intersect the capitellum correctly. Additionally, the **radiocapitellar alignment** refers to the relationship between the **radius head** and the **capitellum**. Fractures and displacements around the elbow joint, such as supracondylar fractures, can disrupt this alignment. *Fracture lateral condyle of the humerus* - While a fracture of the lateral condyle can affect the elbow joint, it primarily involves a part of the **articular surface** and not necessarily the overall alignment of the entire distal humerus relative to the capitellum in the same way a supracondylar fracture does. - The **lateral condyle** is a smaller segment, and its fracture may not significantly alter the anterior humeral line **unless there is significant displacement** that indirectly affects the alignment of the capitellum. *Monteggia Fracture dislocation* - A **Monteggia fracture** involves a fracture of the **ulna** with dislocation of the **radial head** at the elbow. - While radiocapitellar alignment is severely disrupted, the **anterior humeral line** itself, which assesses the distal humerus, is typically **unaffected** as the primary injury is in the forearm bones and the radial head. *Fracture of Proximal Radius* - A fracture of the proximal radius (e.g., **radial head or neck fracture**) primarily affects the **radial articular surface** and its alignment with the capitellum. - While **radiocapitellar alignment** would clearly be disturbed, the position of the **distal humerus** relative to the capitellum, which the anterior humeral line evaluates, usually remains intact.

Q: In which condition is the Hamilton Ruler test sign positive?

Anterior dislocation of shoulder. ***Anterior dislocation of shoulder*** - The **Hamilton Ruler test** is positive when a straight edge, like a ruler, can be laid across the **lateral aspect of the deltoid prominence** from the acromion to the lateral epicondyle. - This is indicative of the **loss of the normal rounded contour of the shoulder**, which occurs due to the humeral head dislocating anteriorly. *Acromioclavicular joint dislocation* - This condition presents with a **"step-off" deformity** at the AC joint and pain directly over the joint, but the overall contour of the shoulder glenohumeral joint is preserved. - The deltoid prominence remains intact, making the Hamilton Ruler test negative. *Posterior dislocation of shoulder* - In posterior dislocation, the **humeral head moves posteriorly**, and the anterior contour of the shoulder might appear flattened, but the characteristic prominent anterior bulge seen in anterior dislocation is absent. - The Hamilton Ruler test specifically assesses for the loss of the lateral deltoid prominence, which is more typical of anterior displacement. *Luxatio erecta* - **Luxatio erecta** is an inferior dislocation of the shoulder where the arm is fixed in an **abducted and externally rotated position**, making it appear "erect". - While a severe type of shoulder dislocation, the specific anatomical changes that lead to a positive Hamilton Ruler test (loss of lateral deltoid prominence with the humeral head moving anteriorly and medially) are not typically present in this configuration.

Q: Which of the following is a long-acting local anesthetic?

Dibucaine. ***Dibucaine*** - **Dibucaine** is a **long-acting amide local anesthetic** with a duration of action up to 10 hours. - Its high **lipid solubility** contributes to its prolonged effect and greater potency compared to other local anesthetics. *Prilocaine* - **Prilocaine** is considered an **intermediate-duration amide local anesthetic**, with a duration of action typically 1-2 hours. - It carries a risk of **methemoglobinemia** at higher doses, which differentiates it from longer-acting agents. *Procaine* - **Procaine** is a **short-acting ester local anesthetic**, with a duration of action usually less than 1 hour. - It is known for its relatively **high allergenicity** due to its metabolism to para-aminobenzoic acid (PABA). *Lignocaine* - **Lignocaine (Lidocaine)** is an **intermediate-acting amide local anesthetic**, with a duration of action around 1-3 hours. - It is one of the most commonly used local anesthetics, but its duration is not as long as that of dibucaine.

Q: What type of respiratory failure is most commonly observed in post-operative patients?

Hypoxemic respiratory failure. ***Hypoxemic respiratory failure*** - **Hypoxemic respiratory failure** (Type I) is characterized by a **PaO2 less than 60 mmHg** with a normal or low PaCO2, often due to **V/Q mismatch** and **shunt**. - Post-operative patients frequently develop **atelectasis**, **pneumonia**, or **pulmonary edema**, leading to impaired gas exchange and reduced oxygenation. - This is the **most commonly observed type** in the immediate post-operative period. *Hypercapnic respiratory failure* - **Hypercapnic respiratory failure** (Type II) is primarily due to **alveolar hypoventilation**, resulting in a **PaCO2 greater than 50 mmHg**. - While it can occur post-operatively, it is less common than hypoxemic failure and is typically seen with significant **sedation**, **neuromuscular blockade**, or severe **obstructive lung disease**. *Mixed respiratory failure* - **Mixed respiratory failure** involves both **hypoxemia** and **hypercapnia**, indicating severe impairment in both oxygenation and ventilation. - Although it can occur in severe post-operative complications, it is not the *most commonly observed initial presentation* compared to isolated hypoxemia. *Perioperative respiratory failure* - **Perioperative respiratory failure** (Type III) occurs specifically in the surgical setting and involves atelectasis from changes in chest wall mechanics. - While this occurs in the post-operative context, the term is less commonly used, and the **underlying mechanism is primarily hypoxemic** in nature.

Question 1

Laryngeal mask airway [LMA] is contraindicated in?

Accepted Answer

Pregnant female

Answer

Ocular surgeries

Answer

Difficult airways

Answer

In CPR

Question 2

Which one of the following agents sensitizes the myocardium to catecholamines?

Accepted Answer

Halothane

Answer

Isoflurane

Answer

Ether

Answer

Propofol

Question 3

Which anesthetic agent is safe to use in patients with elevated intracranial pressure (ICP)?

Accepted Answer

Thiopentone

Answer

Halothane

Answer

Ketamine

Answer

Ether

Question 4

At the end of anaesthesia after discontinuation of nitrous oxide and removal of endotracheal tube, 100% oxygen is administered to the patient to prevent:

Accepted Answer

Diffusion Hypoxia

Answer

Second gas effect

Answer

Bronchospasm

Answer

Hyperoxia

Question 5

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 6

Lift off test is done to assess the function of:

Accepted Answer

Subscapularis muscle function

Answer

Supraspinatus muscle function

Answer

Infraspinatus muscle function

Answer

Teres Minor muscle function

Question 7

The anterior humeral line and radiocapitellar alignment are most commonly disturbed in -

Accepted Answer

Supracondylar Fracture of the humerus

Answer

Monteggia Fracture dislocation

Answer

Fracture of Proximal Radius

Answer

Fracture lateral condyle of the humerus

Question 8

In which condition is the Hamilton Ruler test sign positive?

Accepted Answer

Anterior dislocation of shoulder

Answer

Posterior dislocation of shoulder

Answer

Luxatio erecta

Answer

Acromioclavicular joint dislocation

Question 9

Which of the following is a long-acting local anesthetic?

Accepted Answer

Dibucaine

Answer

Prilocaine

Answer

Procaine

Answer

Lignocaine

Question 10

What type of respiratory failure is most commonly observed in post-operative patients?

Accepted Answer

Hypoxemic respiratory failure

Answer

Hypercapnic respiratory failure

Answer

Mixed respiratory failure

Answer

Perioperative respiratory failure

NEET-PG 2015

Anesthesiology

Orthopaedics

Pharmacology

Surgery