Anesthesiology
2 questionsIn which vein is Central Venous Pressure (CVP) most accurately monitored?
Central venous monitoring is typically used for all of the following except:
NEET-PG 2013 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 881: In which vein is Central Venous Pressure (CVP) most accurately monitored?
- A. Anterior jugular vein
- B. External jugular vein
- C. Inferior vena cava
- D. Internal jugular vein (Correct Answer)
Explanation: ***Internal jugular vein*** - The **internal jugular vein** provides the **most direct and consistent access** to the superior vena cava and right atrium, where CVP is accurately measured. - Its straight course and reliable anatomical landmarks make it a preferred site for CVP catheter insertion. *Anterior jugular vein* - The **anterior jugular vein** is smaller and often has a more tortuous course, making consistent and reliable CVP monitoring difficult. - It is not typically chosen for central venous access due to its anatomical variability and smaller caliber. *External jugular vein* - The **external jugular vein** is superficially located and easier to access but often has valves and a more oblique angle to the subclavian vein, making catheter advancement to the central circulation challenging. - Catheter tip placement is less consistent for accurate CVP measurements compared to the internal jugular vein. *Inferior vena cava* - While the **inferior vena cava** eventually drains into the right atrium, access is typically via the femoral vein, which is associated with a higher risk of infection and deep vein thrombosis for long-term CVP monitoring. - Measurements from the inferior vena cava or femoral vein can be affected by **intra-abdominal pressure** and are not as accurately reflective of right atrial pressure as those from the superior vena cava.
Question 882: Central venous monitoring is typically used for all of the following except:
- A. Administering thrombolytics (Correct Answer)
- B. Deciding the need for plasma infusion
- C. Deciding the requirement for blood transfusion
- D. Regulating the speed and amount of fluid infusion
Explanation: ***Administering thrombolytics*** - Central venous monitoring is a technique used to measure central venous pressure (CVP), which reflects right atrial pressure and indirectly **right ventricular preload**. It does not directly relate to the administration of **thrombolytics**. - Thrombolytics are typically administered intravenously through a peripheral or central line to dissolve clots, but CVP monitoring is not a prerequisite or a direct function of this administration. *Regulating the speed and amount of fluid infusion* - **Central venous pressure (CVP)** monitoring is crucial for assessing a patient's **fluid status** and guiding fluid resuscitation. - By continuously monitoring CVP, clinicians can determine whether to increase, decrease, or maintain the rate of **fluid infusion** to optimize cardiac preload without causing fluid overload. *Deciding the need for plasma infusion* - CVP values help assess **circulatory volume** and guide decisions on fluid replacement, including the need for **plasma infusion** in conditions like severe hypovolemia or coagulopathy. - A low CVP in a patient with bleeding or coagulation issues might indicate the need for volume expansion with **plasma**. *Deciding the requirement for blood transfusion* - **Low CVP** can indicate **hypovolemia**, which might be due to blood loss, thereby suggesting the need for a **blood transfusion**. - While not the sole determinant, CVP is one of several physiological parameters used to assess the urgency and amount of **blood products** required to restore circulating volume and oxygen-carrying capacity.
Internal Medicine
5 questionsAdrenal reserve is best tested by means of infusion with
What is the recommended time frame for completing a blood transfusion after initiation?
What is the recommended rate of correction for sodium deficit in patients with chronic hyponatremia?
Graham Steell murmur is associated with which of the following conditions?
Deep vein thrombosis most commonly occurs at which site?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 881: Adrenal reserve is best tested by means of infusion with
- A. ACTH (Correct Answer)
- B. Metyrapone
- C. Corticosteroids
- D. LHRH
Explanation: ACTH - The **ACTH stimulation test**, also known as the **cosyntropin test**, is the most common dynamic test for assessing adrenal reserve. - Exogenous ACTH (cosyntropin) stimulates the adrenal glands to produce cortisol; a subnormal response indicates adrenal insufficiency. *Corticosteroids* - **Corticosteroids** are hormones (like cortisol) produced by the adrenal glands, or synthetic versions used as medications; they do not test adrenal reserve but rather *replace* adrenal function. - Administering corticosteroids would interfere with, rather than assess, the adrenal gland's ability to produce its own hormones. *LHRH* - **Luteinizing hormone-releasing hormone (LHRH)** is used to assess the function of the anterior pituitary gland and gonads, not the adrenal glands. - An LHRH stimulation test evaluates the pituitary's ability to release LH and FSH, which in turn stimulate gonadal hormone production. *Metyrapone* - The **metyrapone test** assesses the integrity of the **hypothalamic-pituitary-adrenal axis** by blocking cortisol synthesis, which should lead to an increase in ACTH and 11-deoxycortisol [1]. - While it evaluates a part of adrenal function, it is primarily used to differentiate between primary and secondary adrenal insufficiency, and not a direct measure of cortisol production capacity in response to stimulation.
Question 882: What is the recommended time frame for completing a blood transfusion after initiation?
- A. 1-4 hours (Correct Answer)
- B. 3-6 hours
- C. 4-8 hours
- D. 8-12 hours
Explanation: ***1-4 hours*** - This timeframe is recommended to **minimize the risk of bacterial growth** in the blood product, as bacteria can multiply quickly at room temperature. - Completing the transfusion within 4 hours also reduces the likelihood of **red blood cell degeneration** and loss of efficacy. *3-6 hours* - This period extends beyond the recommended maximum of 4 hours, increasing the risk of **bacterial proliferation** in the blood product. - Prolonged infusion times can also lead to a **decrease in the viability and function** of transfused cells. *4-8 hours* - Transfusing over 4-8 hours significantly elevates the risk of **bacterial contamination** and potential septic reactions. - The extended duration compromises the **quality and safety** of the blood product. *8-12 hours* - This timeframe is unacceptably long for a blood transfusion, posing a **critical risk of severe bacterial growth** and infection. - Blood products should not be administered beyond 4 hours due to the rapid decline in **cell integrity and increased adverse reaction potential**.
Question 883: What is the recommended rate of correction for sodium deficit in patients with chronic hyponatremia?
- A. 0.5 mmol/hour (Correct Answer)
- B. 1 mmol/hour
- C. 1.5 mmol/hour
- D. 2.0 mmol/hour
Explanation: ***0.5 mmol/hour*** [1] - This rate of correction is recommended to avoid **osmotic demyelination syndrome (ODS)**, also known as central pontine myelinolysis [1]. - The aim is to correct the sodium deficit gradually, with a maximum increase not exceeding **8-10 mmol/L in any 24-hour period** [1]. *1 mmol/hour* - This rate is generally considered too rapid for chronic hyponatremia and increases the risk of **osmotic demyelination syndrome**. - While acceptable in some acute severe cases, it is typically avoided in chronic settings where the brain has adapted to lower osmolality. *1.5 mmol/hour* - This rate would lead to an even faster correction of sodium, significantly elevating the risk of **osmotic demyelination syndrome**. - It would result in a correction of 36 mmol/L over 24 hours, far exceeding the recommended daily limit of 8-10 mmol/L. *2.0 mmol/hour* - Such a rapid correction rate is highly dangerous and almost guarantees the development of **osmotic demyelination syndrome**. - This aggressive correction would lead to severe brain injury due to rapid osmotic shifts.
Question 884: Graham Steell murmur is associated with which of the following conditions?
- A. Pulmonary Regurgitation (PR) (Correct Answer)
- B. Tricuspid Regurgitation (TR)
- C. Tricuspid Stenosis (TS)
- D. Pulmonary Stenosis (PS)
Explanation: ***Pulmonary Regurgitation (PR)*** - The **Graham Steell murmur** is a high-pitched, decrescendo early diastolic murmur heard best at the left sternal border associated with **pulmonary hypertension**. [1] - It results from dilation of the pulmonary artery due to **elevated pulmonary pressures**, leading to functional pulmonary valve regurgitation. [1] *Tricuspid Regurgitation (TR)* - TR typically presents as a **holosystolic murmur** best heard at the left lower sternal border, often increasing with inspiration (Carvallo's sign). - It is caused by improper coaptation of the tricuspid valve leaflets, often due to **right ventricular dilation**. *Tricuspid Stenosis (TS)* - TS is characterized by a **diastolic rumble** heard best at the lower left sternal border, often with an opening snap. [2] - It is relatively rare and often associated with **rheumatic heart disease**. *Pulmonary Stenosis (PS)* - PS typically produces a **systolic ejection murmur** heard at the upper left sternal border, often radiating to the back. - It is caused by **obstruction to blood flow** from the right ventricle to the pulmonary artery.
Question 885: Deep vein thrombosis most commonly occurs at which site?
- A. Femoral vein (Correct Answer)
- B. Subclavian vein
- C. External jugular vein
- D. Internal jugular vein
Explanation: ***Femoral vein*** - The **femoral vein**, along with the **popliteal** and **iliac veins**, are the most common sites for **deep vein thrombosis (DVT)** in the lower extremities [1]. - Due to their size and the dynamics of blood flow in these regions, they are prone to clot formation, especially in the presence of **Virchow's triad**. *Subclavian vein* - While DVT can occur in the subclavian vein (an **upper extremity DVT**), it is less common than in the lower extremities [1]. - Upper extremity DVTs are often associated with **central venous catheters** or **thoracic outlet syndrome**. *External jugular vein* - **External jugular vein thrombosis** is rare and usually associated with local trauma, infection, or central line placement, not typically primary DVT [1]. - It is a superficial vein and not considered a common site for typical deep vein thrombosis. *Internal jugular vein* - **Internal jugular vein thrombosis** is also uncommon as a primary DVT and often secondary to neck infections, malignancies, or indwelling catheters [1]. - Like the subclavian vein, it's considered an upper extremity DVT site, but less frequent than lower extremity sites.
Pediatrics
1 questionsAt what age can an infant typically achieve head control or neck holding?
NEET-PG 2013 - Pediatrics NEET-PG Practice Questions and MCQs
Question 881: At what age can an infant typically achieve head control or neck holding?
- A. 1 month
- B. 2 months
- C. 3 months (Correct Answer)
- D. 6 months
Explanation: ***3 months*** - By **3 months** of age, an infant typically develops sufficient **neck muscle strength** and control to hold their head steady when sitting upright or pulled to a sit. - This milestone indicates maturation of the **cervical muscles** and nervous system coordination necessary for head stability. *1 month* - At **1 month**, an infant usually has very little head control and their head will **lag significantly** when pulled to a sitting position. - Neck muscles are still relatively weak, and the infant is unable to maintain the head in an upright posture against gravity. *2 months* - While some improvement in head control may be observed around **2 months**, the infant's head will still generally **wobble** and lag when moved. - Sustained, steady head holding is not typically achieved at this age, and support is still largely required. *6 months* - By **6 months**, an infant should have **excellent head control** and be able to easily hold their head steady and upright. - This age marks the development of other motor milestones like sitting with support or independently, which require strong neck and core muscles.
Pharmacology
1 questionsWhat is the drug of choice for managing generalized tonic-clonic seizures (GTCS) during pregnancy?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 881: What is the drug of choice for managing generalized tonic-clonic seizures (GTCS) during pregnancy?
- A. Lamotrigine (Correct Answer)
- B. CBZ
- C. Levetiracetam
- D. Valproate
Explanation: ***Lamotrigine*** - **Lamotrigine** is considered **one of the preferred drugs** for managing epilepsy during pregnancy due to its relatively **low teratogenic risk** compared to older antiepileptic drugs. - Its established safety profile in pregnancy makes it a preferred option to balance seizure control and **fetal well-being**. - **Important Note:** For **GTCS specifically**, lamotrigine and levetiracetam are both considered appropriate first-line choices, with selection depending on individual patient factors and seizure control history. - Lamotrigine levels **decrease during pregnancy** and require monitoring and dose adjustments. *CBZ* - **Carbamazepine (CBZ)** is associated with an increased risk of **neural tube defects** and other congenital malformations when used during pregnancy, making it less favorable. - While effective for GTCS, its teratogenicity often leads to avoidance or careful consideration of alternatives in pregnant women. *Levetiracetam* - **Levetiracetam** is increasingly recognized as an **excellent choice for GTCS in pregnancy** with a favorable safety profile and growing evidence base. - Many recent guidelines and clinical practices favor levetiracetam as **first-line for GTCS** due to its low risk of major congenital malformations and good efficacy. - It is a **medically appropriate alternative** to lamotrigine, and in some contexts may be preferred, particularly for primary generalized epilepsy. *Valproate* - **Valproate** has the highest risk of **teratogenicity** among common antiepileptic drugs, including a significant risk of **neural tube defects**, developmental delay, autism spectrum disorder, and other anomalies. - Due to these significant risks, valproate is generally **contraindicated** in women of childbearing potential, especially during pregnancy, unless no other effective and safer alternative exists.
Radiology
1 questionsThe most accurate investigation for assessing ventricular function is:
NEET-PG 2013 - Radiology NEET-PG Practice Questions and MCQs
Question 881: The most accurate investigation for assessing ventricular function is:
- A. Multislice CT
- B. Echocardiography
- C. MRI (Correct Answer)
- D. Nuclear scan
Explanation: ***MRI*** - Cardiac MRI is considered the **gold standard** for assessing ventricular function, providing highly accurate and reproducible measurements of **ventricular volumes**, **ejection fraction**, and **myocardial mass**. - It offers excellent tissue characterization, allowing for direct visualization of **fibrosis**, **inflammation**, and other myocardial pathologies that can affect function. *Multislice CT* - While useful for assessing cardiac anatomy, particularly **coronary arteries**, Multislice CT involves **ionizing radiation** and has limitations in accurately assessing subtle changes in myocardial function compared to MRI. - Its strength lies more in **anatomical evaluation** (e.g., calcium scoring, coronary angiography) rather than detailed functional assessment. *Echocardiography* - Echocardiography is a widely available and useful first-line imaging modality for ventricular function, but it can be limited by **acoustic windows**, **operator dependency**, and **spatial resolution** compared to MRI. - While it provides good estimates of ejection fraction, particularly in simple cases, its 3D capabilities and tissue characterization are generally inferior to MRI. *Nuclear scan* - Nuclear scans (e.g., MUGA scans, SPECT) can assess ventricular function and myocardial perfusion, but they involve **ionizing radiation** and primarily provide **functional information** based on tracer uptake, not detailed structural or tissue characterization. - They are often used for evaluating **perfusion defects** and overall ejection fraction, but are less precise for detailed chamber quantification and tissue characterization than MRI.