UPSC-CMS 2021 - Anesthesiology PYQs Practice Questions

Q: Which one of the following is a Nephrotoxic anaesthetic agent ?

Methoxyflurane. ***Methoxyflurane*** - **Methoxyflurane** is an inhaled anesthetic that can cause dose-dependent **nephrotoxicity** due to the metabolic release of **fluoride ions**. - Its use is limited due to the risk of **renal dysfunction**, including **high-output renal failure**, especially with prolonged administration or high concentrations. *Nitrous oxide* - **Nitrous oxide** is an inhaled anesthetic known for its analgesic properties and low solubility, leading to rapid onset and offset. - It does not typically cause **direct organ toxicity** like nephrotoxicity, though prolonged exposure can affect bone marrow. *Halothane* - **Halothane** is an older inhaled anesthetic associated with **hepatotoxicity** (halothane hepatitis) in some susceptible individuals. - While it can cause liver damage, it is not primarily known for causing **nephrotoxicity**. *Isoflurane* - **Isoflurane** is a commonly used inhaled anesthetic known for its relatively stable cardiovascular effects and low metabolic degradation. - It is generally considered to have a **good safety profile** with minimal organ toxicity, including the kidneys. [Practice more Anesthesiology PYQs on OnCourse]

Q: A comatose patient after sustaining severe head injury has been admitted to the neurosurgical ICU. Which of the following parameters should ideally be maintained in this patient? 1. pCO2 = 4.5 - 5.0 kPa (33-38 mm Hg) 2. MAP = 80 - 90 mm of Hg 3. pO2 > 11 kPa (> 80 mm Hg) 4. Na+ < 130 meq/L

1, 2 and 3. ***1, 2 and 3*** - Maintaining **pCO2 between 4.5-5.0 kPa (33-38 mmHg)** helps optimize cerebral blood flow; values outside this range can cause vasoconstriction or vasodilation, affecting intracranial pressure (ICP). - A **mean arterial pressure (MAP) of 80-90 mmHg** ensures adequate cerebral perfusion pressure (CPP) and minimizes the risk of secondary brain injury from ischemia. - An **arterial partial pressure of oxygen (pO2) above 11 kPa (>80 mmHg)** is crucial to prevent cerebral hypoxia, which can exacerbate brain damage in severely injured patients. *2, 3 and 4* - This option correctly identifies the importance of maintaining adequate MAP and pO2 but incorrectly suggests a low sodium level. - A low **serum sodium (Na+) below 130 mEq/L (hyponatremia)** should be avoided in severe head injury as it can worsen cerebral edema and increase ICP. *1, 2 and 4* - While maintaining pCO2 and MAP within target ranges is essential, a **sodium level below 130 mEq/L (hyponatremia)** is detrimental and not an ideal parameter to maintain. - Hyponatremia can lead to further **brain swelling** and increased intracranial pressure. *1, 3 and 4* - This combination correctly identifies ideal pCO2 and pO2 targets but incorrectly includes **hyponatremia (Na+ < 130 mEq/L)** as a desirable parameter. - Severe hyponatremia can cause significant neurological complications including **seizures** and worsening cerebral edema. [Practice more Anesthesiology PYQs on OnCourse]

Q: Perioperative benefit from transfusion is with a haemoglobin level of

6 - 8 gm/dl. **6 - 8 gm/dl** - Transfusions are generally recommended for **symptomatic anemia** or when the hemoglobin level falls below **7 g/dL** in most patients. - For patients undergoing surgery, a hemoglobin range of **6-8 gm/dl** often indicates a need for transfusion to optimize oxygen delivery and prevent complications. *8 - 10 gm/dl* - Hemoglobin levels in this range are often considered stable enough for many patients, and transfusion may not be necessary unless there are specific **cardiovascular risks** or **acute bleeding**. - Routine transfusion for non-symptomatic patients with hemoglobin in this range has not shown significant perioperative benefit and can expose patients to transfusion risks. *< 6 gm/dl* - A hemoglobin level below **6 gm/dl** typically indicates **severe anemia** and almost always warrants transfusion regardless of surgical context due to the high risk of **tissue hypoxia** and organ dysfunction. - While transfusion is definitely beneficial in this range, the question asks about the range where benefit *commences* for perioperative settings, which typically falls slightly higher to prevent severe drops. *> 10 gm/dl* - A hemoglobin level **above 10 gm/dl** is generally considered good and does not usually require transfusion, even in the perioperative setting. - Transfusing patients with hemoglobin levels above this threshold is associated with **no significant clinical benefit** and increases the risk of transfusion-related adverse events. [Practice more Anesthesiology PYQs on OnCourse]

Question 1

Which one of the following is a Nephrotoxic anaesthetic agent ?

Accepted Answer

Methoxyflurane

Answer

Nitrous oxide

Answer

Halothane

Answer

Isoflurane

Question 2

A comatose patient after sustaining severe head injury has been admitted to the neurosurgical ICU. Which of the following parameters should ideally be maintained in this patient?

1. pCO2 = 4.5 - 5.0 kPa (33-38 mm Hg)

2. MAP = 80 - 90 mm of Hg

3. pO2 > 11 kPa (> 80 mm Hg)

4. Na+ < 130 meq/L

Accepted Answer

1, 2 and 3

Answer

2, 3 and 4

Answer

1, 2 and 4

Answer

1, 3 and 4

Question 3

Perioperative benefit from transfusion is with a haemoglobin level of

Accepted Answer

6 - 8 gm/dl

Answer

8 - 10 gm/dl

Answer

< 6 gm/dl

Answer

> 10 gm/dl

UPSC-CMS 2021 — Anesthesiology