Anesthesiology
4 questionsInhalational agent of choice for neurosurgery?
Which of the following statements about Nitrous Oxide (N2O) is true?
Which drug is commonly used for emergency intubation?
Which of the following statements is NOT true regarding rapid induction of anesthesia?
NEET-PG 2013 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 1241: 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.
Question 1242: 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 1243: 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 1244: 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.
Internal Medicine
1 questionsA female patient presents with hirsutism, amenorrhea, and obesity. What is the most likely diagnosis?
NEET-PG 2013 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 1241: A female patient presents with hirsutism, amenorrhea, and obesity. What is the most likely diagnosis?
- A. Androgen-secreting ovarian tumor
- B. Congenital adrenal hyperplasia
- C. Cushing's syndrome
- D. Polycystic Ovary Syndrome (PCOS) (Correct Answer)
Explanation: ***Polycystic Ovary Syndrome (PCOS)*** - **Hirsutism**, **amenorrhea** (or oligomenorrhea), and **obesity** are classic clinical features of PCOS, reflecting hyperandrogenism and insulin resistance [2]. - PCOS is a diagnosis of exclusion and involves chronic anovulation and polycystic ovaries on ultrasound [3], though these are not explicitly mentioned, the constellation of symptoms strongly points to it. *Androgen-secreting ovarian tumor* - While it can cause **hirsutism** and **amenorrhea**, the onset is typically **rapid** and severe, with very high androgen levels, and obesity is not a primary feature. - Ovarian tumors are generally less common than PCOS and may present with a palpable mass or specific imaging findings. *Congenital adrenal hyperplasia* - This genetic condition often presents in childhood or adolescence with varying degrees of **virilization** and menstrual irregularities due to enzyme deficiencies in cortisol synthesis [1]. - While it causes **hirsutism** and potentially **amenorrhea**, obesity is not a direct consequence, and the patient's age of presentation and specific symptom pattern are less typical for adult-onset CAH in this context. *Cushing's syndrome* - Characterized by **central obesity**, **moon facies**, **buffalo hump**, **striae**, and proximal muscle weakness due to chronic glucocorticoid excess. - Although it can cause **menstrual irregularities** and mild **hirsutism** [2], the overall clinical picture including the absence of other specific Cushingoid features makes it less likely than PCOS.
Obstetrics and Gynecology
4 questionsWhich condition is associated with HAIR-AN syndrome?
Which hormone is known to be elevated in Polycystic Ovary Syndrome (PCOS)?
In Stein-Leventhal syndrome, which hormone is raised?
Which of the following actions should be avoided during the delivery of an Rh-negative mother?
NEET-PG 2013 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 1241: Which condition is associated with HAIR-AN syndrome?
- A. CA ovary
- B. Adrenal tumours
- C. Endometriosis
- D. Polycystic Ovary Syndrome (PCOS) (Correct Answer)
Explanation: ***Polycystic Ovary Syndrome (PCOS)*** - **HAIR-AN syndrome** is a specific, severe form of **PCOS**, characterized by **HyperAndrogenism**, **Insulin Resistance**, and severe **Acanthosis Nigricans**. - It represents the most pronounced metabolic and endocrine abnormalities associated with PCOS, often with significant hyperinsulinemia. *Endometriosis* - Endometriosis involves the growth of **endometrial-like tissue outside the uterus**, causing pain and infertility. - It is not directly linked to the metabolic and hormonal disturbances seen in HAIR-AN syndrome. *CA ovary* - **Ovarian cancer** is a malignant proliferation of ovarian cells, which is not associated with the unique features of **hyperandrogenism**, **insulin resistance**, or **acanthosis nigricans** that define HAIR-AN syndrome. - Ovarian tumors can be hormone-producing, but this is distinct from the syndrome's chronic metabolic dysregulation. *Adrenal tumours* - **Adrenal tumors** can cause **hyperandrogenism** in some cases, leading to symptoms like hirsutism, but they typically do not present with the constellation of **insulin resistance** and severe **acanthosis nigricans** that define HAIR-AN syndrome. - The primary defect in HAIR-AN is ovarian and metabolic, rather than adrenal.
Question 1242: Which hormone is known to be elevated in Polycystic Ovary Syndrome (PCOS)?
- A. FSH
- B. Estrogen
- C. TSH
- D. Luteinizing Hormone (LH) (Correct Answer)
Explanation: ***Luteinizing Hormone (LH)*** - In **Polycystic Ovary Syndrome (PCOS)**, there is often an elevated **Luteinizing Hormone (LH)** level, leading to an increased **LH:FSH ratio**. - This high LH level contributes to **increased androgen production** by the ovaries, a key feature of PCOS. *FSH* - **Follicle-stimulating hormone (FSH)** levels are typically normal or even low in PCOS, contributing to the **imbalance with LH**. - This relative deficiency of FSH impairs proper **follicle maturation**, leading to anovulation and cyst formation. *Estrogen* - While **estrogen** levels can be normal or slightly elevated due to peripheral conversion of androgens, they are not primarily responsible for the characteristic hormonal imbalance in PCOS. - The elevated **androgens** in PCOS are converted to estrogen in adipose tissue, but this is a secondary effect. *TSH* - **Thyroid-stimulating hormone (TSH)** is involved in thyroid function and is generally unrelated to the **pathophysiology of PCOS**, although thyroid disorders can co-exist with PCOS. - Elevated TSH suggests **hypothyroidism**, a distinct endocrine condition that would present with different symptoms.
Question 1243: In Stein-Leventhal syndrome, which hormone is raised?
- A. LH (Correct Answer)
- B. FSH
- C. GnRH
- D. Progesterone
Explanation: ***LH*** - In **Stein-Leventhal syndrome** (Polycystic Ovary Syndrome, PCOS), there is an elevated **LH (Luteinizing Hormone)** level. - This high LH-to-FSH ratio contributes to increased **androgen production** by the ovarian theca cells, leading to symptoms like hirsutism and anovulation. *FSH* - **FSH (Follicle-Stimulating Hormone)** levels are typically normal or even low in PCOS, contributing to the elevated LH:FSH ratio. - Low FSH levels impair proper follicle maturation, leading to **anovulation** and the characteristic polycystic appearance of the ovaries. *GnRH* - **GnRH (Gonadotropin-Releasing Hormone)** secretion can be altered in PCOS, often showing increased pulse frequency, which preferentially stimulates LH release over FSH. - However, **GnRH levels themselves are not directly measured** as "raised" in the clinical diagnostic criteria for PCOS. *Progesterone* - **Progesterone** levels are often low or absent in PCOS, particularly in the luteal phase, due to **anovulation**. - The lack of regular ovulation means no corpus luteum forms, which is responsible for progesterone production after ovulation.
Question 1244: Which of the following actions should be avoided during the delivery of an Rh-negative mother?
- A. Gently perform manual removal of placenta if necessary (Correct Answer)
- B. Withhold ergometrine until after anterior shoulder delivery
- C. Administer IV fluids
- D. Apply fundal pressure during second stage of labor
Explanation: ***Gently perform manual removal of placenta if necessary*** - **Manual removal of the placenta** can significantly increase the risk of **fetomaternal hemorrhage**, which is particularly dangerous in an **Rh-negative mother**. Large amounts of fetal blood entering the maternal circulation can lead to significant alloimmunization, making subsequent pregnancies high-risk. - This procedure should be **avoided if possible** due to the heightened risk of sensitizing the mother to Rh antigens; if it is absolutely necessary, a **higher dose of Rh immunoglobulin** may be required. *Withhold ergometrine until after anterior shoulder delivery* - **Ergometrine** is a uterotonic agent used to prevent **postpartum hemorrhage**. Withholding it until after the birth of the anterior shoulder is a **standard practice** to prevent uterine tetany before the baby is fully delivered. - This action does not pose a specific risk to an **Rh-negative mother** related to Rh sensitization; it is a general obstetric safety measure to ensure safe delivery and should **not be avoided**. *Apply fundal pressure during second stage of labor* - **Fundal pressure** (applying pressure to the top of the uterus to expedite delivery) is a **controversial practice** that is generally discouraged due to potential maternal and fetal complications. - While it may theoretically carry a small risk of **fetomaternal hemorrhage**, it is not specifically contraindicated in Rh-negative mothers more than in others. The main concerns are **uterine rupture**, **maternal injury**, and **fetal trauma**. If appropriate precautions with **Rh immunoglobulin** are taken, Rh status alone is not a reason to avoid this practice (though it should generally be avoided for other safety reasons). *Administer IV fluids* - **Intravenous fluids** are commonly administered during labor and delivery to maintain **hydration**, support **blood pressure**, and provide a route for medications. This is a **routine and safe practice**. - Administering IV fluids has no direct impact on **Rh sensitization** and is not contraindicated in an **Rh-negative mother**.
Pharmacology
1 questionsWhich of the following statements about Selective Estrogen Receptor Modulators (SERMs) is correct?
NEET-PG 2013 - Pharmacology NEET-PG Practice Questions and MCQs
Question 1241: Which of the following statements about Selective Estrogen Receptor Modulators (SERMs) is correct?
- A. Act as agonists on estrogen receptors.
- B. Some SERMs can act as both agonists and antagonists on estrogen receptors. (Correct Answer)
- C. Used to reduce the risk of hot flushes and thromboembolism.
- D. Act as antagonists on estrogen receptors.
Explanation: ***Some SERMs can act as both agonists and antagonists on estrogen receptors.*** - **SERMs** (Selective Estrogen Receptor Modulators) exert tissue-specific effects, meaning they can act as an **estrogen receptor agonist** in some tissues while acting as an **antagonist** in others. - This **selective mechanism** allows them to confer beneficial estrogenic effects where desired (e.g., bone) and anti-estrogenic effects where unwanted (e.g., breast tissue). *Act as agonists on estrogen receptors.* - This statement is incomplete because while some SERMs can act as **agonists** in certain tissues (e.g., affecting bone density), they are not pure agonists across all tissues. - Their defining characteristic is their **selective action**, exhibiting mixed agonist and antagonist effects depending on the tissue. *Used to reduce the risk of hot flushes and thromboembolism.* - SERMs like **tamoxifen** and **raloxifene** can actually **increase the risk** of both hot flushes and thromboembolism. - **Hot flushes** occur due to their **anti-estrogenic effects** on the hypothalamus, which disrupts thermoregulation. - **Thromboembolism** risk is increased due to their **estrogenic (agonist) effects** on hepatic synthesis of coagulation factors. *Act as antagonists on estrogen receptors.* - This statement is also incomplete because, while some SERMs exhibit **antagonist activity** in certain tissues (e.g., the breast), they simultaneously act as **agonists** in other tissues (e.g., bone or endometrium). - A pure antagonist would block estrogen receptors in all tissues, which is not the defining feature of SERMs.