Anesthesiology
3 questionsAll are contraindications of this anesthesia technique except: (Recent NEET Pattern 2016-17)
Which finding indicates correct placement of needle in this nerve block? (Recent NEET Pattern 2016-17)
Which is correct about the anesthetic drugs X and Y in the image shown? (Recent NEET Pattern 2016-17)
NEET-PG 2017 - Anesthesiology NEET-PG Practice Questions and MCQs
Question 351: All are contraindications of this anesthesia technique except: (Recent NEET Pattern 2016-17)
- A. Bleeding diathesis
- B. Severe aortic stenosis
- C. Aortic aneurysm (Correct Answer)
- D. Uncooperative patient
Explanation: ***Aortic aneurysm*** - An **aortic aneurysm** is not a contraindication for **epidural anesthesia**. In fact, epidural anesthesia can be beneficial for patients with aortic aneurysms during surgical repair as it can help stabilize hemodynamics and provide effective pain control. - The image shows a needle entering the **epidural space**, indicating this question pertains to epidural anesthesia. *Bleeding diathesis* - **Bleeding diathesis** is a **relative contraindication** for **epidural anesthesia** due to the increased risk of **epidural hematoma**, which can cause neurological damage. - The formation of an **epidural hematoma** can lead to spinal cord compression. *Severe aortic stenosis* - **Severe aortic stenosis** is a **contraindication** for **epidural anesthesia** because the associated **vasodilation** from regional anesthesia can lead to a drastic drop in blood pressure, which these patients cannot tolerate as their fixed cardiac output relies on adequate preload. - Patients with **severe aortic stenosis** are highly susceptible to **hypotension** and cardiac collapse. *Uncooperative patient* - An **uncooperative patient** is a **contraindication** for **epidural anesthesia** as proper positioning and patient cooperation are crucial for safe needle placement. - Lack of cooperation increases the risk of **neurological injury** during the procedure.
Question 352: Which finding indicates correct placement of needle in this nerve block? (Recent NEET Pattern 2016-17)
- A. Increase in skin temperature of ipsilateral arm (Correct Answer)
- B. Decrease in skin temperature of ipsilateral arm
- C. Increase in sweating of ipsilateral arm
- D. Decrease in sweating of ipsilateral arm
Explanation: ***Increase in skin temperature of ipsilateral arm*** - A successful **stellate ganglion block** interrupts the **sympathetic efferent fibers** that innervate the ipsilateral arm. - This interruption leads to **vasodilation** in the blood vessels of the arm, resulting in increased blood flow and thus, a rise in skin temperature. *Decrease in skin temperature of ipsilateral arm* - A decrease in skin temperature would indicate **vasoconstriction**, which is the opposite effect of a successful sympathetic block. - This would suggest either an ineffective block or stimulation of sympathetic activity. *Increase in sweating of ipsilateral arm* - The stellate ganglion also carries **sympathetic fibers** to the sweat glands. A successful block would inhibit sweat gland activity. - Increased sweating (known as **diaphoresis**) would indicate an inadequate block or irritation of the ganglion, leading to increased sympathetic outflow. *Decrease in sweating of ipsilateral arm* - While a **decrease in sweating** (anhidrosis) is indeed a sign of effective sympathetic blockade to the arm, it is typically less immediate and less clinically observable than the change in skin temperature. - The most easily and consistently observed sign of sympathetic denervation in the arm is the increase in skin temperature due to vasodilation.
Question 353: Which is correct about the anesthetic drugs X and Y in the image shown? (Recent NEET Pattern 2016-17)
- A. Drug X and Y have equally fast onset of action
- B. Drug X and Y have equally fast onset of action but potency of X is more than Y
- C. Drug Y is more fast acting than X
- D. Drug X is more fast acting than Y (Correct Answer)
Explanation: ***Drug X is more fast acting than Y*** - The **oil:gas partition coefficient** for Drug X is lower than for Drug Y. A lower oil:gas partition coefficient typically correlates with a **faster onset of action** for inhaled anesthetics as it indicates lower solubility in blood and tissues, allowing for quicker equilibration in the brain. - While MAC is plotted against oil:gas partition coefficient, the question specifically asks about **onset of action**, which is primarily influenced by blood-gas solubility rather than oil-gas solubility. However, an anesthetic with lower oil-gas solubility (like X) would generally also have lower blood-gas solubility, leading to faster onset. *Drug Y is more fast acting than X* - Drug Y has a **higher oil:gas partition coefficient** compared to Drug X, indicating greater lipid solubility. - A higher oil:gas partition coefficient generally correlates with a **slower onset of action** for inhaled anesthetics, as more drug dissolves in lipids before reaching the brain. *Drug X and Y have equally fast onset of action* - The graph clearly shows that Drug X and Drug Y have different **oil:gas partition coefficients**. - Since the partition coefficients are different, their **solubility characteristics** and therefore their clinical onset of action would also be different. *Drug X and Y have equally fast onset of action but potency of X is more than Y* - Onset of action is **not equal** for X and Y due to their differing oil:gas partition coefficients. - Potency, represented by **MAC** (Minimum Alveolar Concentration), is inversely related to the oil:gas partition coefficient for many inhaled anesthetics. From the graph, Drug X has a higher MAC value than Drug Y (meaning it is **less potent** but acts faster).
Pharmacology
1 questionsThe application of the following product can lead to development of: (Recent NEET Pattern 2016-17)
NEET-PG 2017 - Pharmacology NEET-PG Practice Questions and MCQs
Question 351: The application of the following product can lead to development of: (Recent NEET Pattern 2016-17)
- A. Seizures
- B. Methemoglobinemia (Correct Answer)
- C. Depression
- D. Hypertension
Explanation: ***Methemoglobinemia (Correct)*** - EMLA cream contains **lidocaine** and **prilocaine**, both of which are **amide-type local anesthetics** - Prilocaine, in particular, can cause methemoglobinemia due to its metabolite, **o-toluidine**, which oxidizes hemoglobin to methemoglobin - While methemoglobinemia is rare with proper use, it is a known and serious adverse effect, especially when applied to large areas, on broken skin, or in infants - This is the most specific adverse effect associated with prilocaine in EMLA cream *Seizures (Incorrect)* - Seizures are a known systemic toxicity of local anesthetics like lidocaine and prilocaine but are usually associated with **very high systemic concentrations**, often from accidental intravenous injection or excessive application over large areas - While possible with overdose, methemoglobinemia is a more specific and direct concern linked to prilocaine's metabolic pathway - CNS toxicity typically requires systemic absorption beyond what occurs with proper topical use *Depression (Incorrect)* - Depression is **not a direct or common adverse effect** of EMLA cream or its components - Systemic absorption of local anesthetics can cause central nervous system effects, but depression is generally not among them - CNS effects more commonly involve excitation (restlessness, tremors) or sedation depending on the dose *Hypertension (Incorrect)* - Local anesthetics generally cause **vasodilation** at therapeutic doses, potentially leading to **hypotension** rather than hypertension, especially with systemic absorption - Hypertension is not a characteristic side effect associated with the topical application of EMLA cream - The cardiovascular effects of local anesthetics, when present, typically involve decreased blood pressure and myocardial depression