Anesthetic Equipment and Monitoring — MCQs

Anesthetic Equipment and Monitoring Indian Medical PG Practice Questions and MCQs

Question 361: The reversal by sugammadex is possible with all the following neuromuscular blocker except-

A. Vecuronium
B. Atracurium (Correct Answer)
C. Pancuronium
D. Rocuronium

Explanation: ***Atracurium*** - **Sugammadex** is a modified gamma-cyclodextrin that specifically encapsulates and inactivates **aminosteroid neuromuscular blocking agents**. - **Atracurium** is a **benzylisoquinolinium** agent, not an aminosteroid, therefore it cannot be reversed by sugammadex. *Vecuronium* - **Vecuronium** is an **aminosteroid neuromuscular blocker**, which means it can be effectively encapsulated and reversed by **sugammadex**. - Its chemical structure allows for a high affinity binding with sugammadex, leading to rapid reversal of neuromuscular blockade. *Pancuronium* - **Pancuronium** is an **aminosteroid neuromuscular blocker** that can be effectively reversed by **sugammadex**. - Although sugammadex has a lower affinity for pancuronium compared to rocuronium, it can still effectively reverse its blockade. *Rocuronium* - **Rocuronium** is an **aminosteroid neuromuscular blocker** with the **highest affinity for sugammadex**, making it the most rapidly and effectively reversed by this agent. - The strong, non-covalent binding between sugammadex and rocuronium forms a stable complex, preventing rocuronium from interacting with acetylcholine receptors.

Question 362: Curare notch seen in capnograph is due to

A. Spontaneous breathing (Correct Answer)
B. Carbon dioxide rebreathing
C. Valve malfunction
D. Bronchospasm

Explanation: ***Spontaneous breathing*** - The "Curare notch" a dip in the expiratory plateau of the **capnograph waveform**, occurs when a patient begins to initiate **spontaneous breaths** against the ventilator. - This signifies that the **neuromuscular blockade** from paralytic agents (like curare derivatives) is wearing off. *Carbon dioxide rebreathing* - **CO2 rebreathing** would typically elevate the baseline of the capnogram and potentially prolong the expiratory plateau, but it would not create a characteristic notch. - This is usually caused by insufficient fresh gas flow or a faulty absorbent, leading to the patient inhaling previously exhaled CO2. *Valve malfunction* - A **valve malfunction**, such as a stuck expiratory valve, would typically cause a persistent elevation of the expiratory CO2 plateau or an inability to exhale, rather than a transient notch. - This would indicate a problem with the mechanical ventilation circuit. *Bronchospasm* - **Bronchospasm** typically results in a **sloping or shark fin-shaped expiratory plateau** on the capnogram due to prolonged expiration and uneven gas emptying from the lungs. - It does not produce a distinct "notch" as seen with the return of spontaneous breathing.

Question 363: Colour of oxygen cylinder is –

A. Grey
B. Black with white shoulder (Correct Answer)
C. Blue
D. White

Explanation: ***Black with white shoulder*** - Medical oxygen cylinders are typically **black** with a **white shoulder** to allow for clear identification. - This standardized color coding helps healthcare professionals quickly distinguish oxygen from other medical gases. *Grey* - Grey cylinders are commonly used for **carbon dioxide** in medical settings. - Using a grey cylinder for oxygen would be a **safety hazard** due to incorrect gas delivery. *Blue* - Blue cylinders are typically designated for **nitrous oxide** (laughing gas). - Administering nitrous oxide instead of oxygen could lead to **hypoxia and adverse patient outcomes**. *White* - White cylinders are often used to identify **compressed air** in medical facilities. - Confusion with compressed air could lead to a lack of oxygen delivery to a patient in need, which is **life-threatening**.

Question 364: Anaesthesia contraindicated In volvulus of gut is

A. Pancuronium
B. Halothane
C. Ketamine
D. Nitrous oxide (Correct Answer)

Explanation: ***Nitrous oxide*** - **Nitrous oxide** diffuses rapidly into gas-filled spaces, which can exacerbate bowel distension in cases of volvulus, increasing the risk of perforation or tension pneumoperitoneum. - Its use can lead to a significant increase in bowel volume and pressure, which is particularly dangerous when the gut is already obstructed and potentially ischemic. *Pancuronium* - **Pancuronium** is a non-depolarizing muscle relaxant that provides good muscle relaxation for surgery, which is often beneficial during abdominal procedures like volvulus repair. - It does not significantly affect bowel volume or blood flow, making it a safe choice for muscle paralysis. *Halothane* - **Halothane** is an inhaled anesthetic that causes general anesthesia and muscle relaxation. - While it can cause some myocardial depression and arrhythmias, it does not directly expand bowel gas and can be used safely in volvulus if cardiovascular status is stable. *Ketamine* - **Ketamine** is a dissociative anesthetic that can be used for induction and maintenance of anesthesia. - It does not cause gas expansion within the bowel and can be a suitable choice, especially in hypotensive patients due to its sympathomimetic effects which help maintain cardiovascular stability.

Question 365: All are used to produce controlled hypotension except

A. Nitroglycerine
B. Isoflurane
C. Propofol (Correct Answer)
D. Esmolol

Explanation: ***Propofol*** - While propofol can cause hypotension, it is primarily used as an **intravenous anesthetic** for induction and maintenance and for sedation. - Its hypotensive effect is a common side effect due to **vasodilation** and decreased cardiac output, but it is not typically optimized or used as a primary agent for controlled hypotension in a surgical setting. *Nitroglycerine* - **Nitroglycerine** is a potent vasodilator, primarily acting on veins, and is commonly used to induce **controlled hypotension** during surgery by reducing preload and afterload. - Its rapid onset and short duration of action make it suitable for titrating blood pressure. *Isoflurane* - **Isoflurane** is an inhaled anesthetic that causes dose-dependent myocardial depression and vasodilation, leading to a decrease in blood pressure. - It is frequently used to provide **controlled hypotension** during surgical procedures. *Esmolol* - **Esmolol** is a rapid-acting, ultra-short-acting beta-blocker that can reduce blood pressure by decreasing heart rate and myocardial contractility. - It is often used to manage **hypertension** and to induce controlled hypotension, especially when a rapid and reversible effect is desired.

Question 366: Size of the laryngeal mask airway for normal adults-

A. 2.5
B. 4
C. 1.5
D. 3 (Correct Answer)

Explanation: ***3*** - A size **3 LMA** is generally recommended for an average adult, especially adult females, weighing approximately 30-50 kg. - This size provides an adequate seal for ventilating normal adult airways when a larger LMA (size 4 or 5) may not be suitable based on patient size or anatomy. *2.5* - A size **2.5 LMA** is typically used for older children (ages 6-12 years) or smaller pediatric patients, not normal adults. - Using a size 2.5 in an adult would likely result in an inadequate seal and poor ventilation. *4* - A size **4 LMA** is commonly used for larger adult males weighing approximately 50-70 kg or more. - While suitable for some adults, it may be too large for an "average" adult, potentially causing pharyngeal trauma or poor positioning. *1.5* - A size **1.5 LMA** is designed for infants or very small children, typically those weighing 5-10 kg. - This size is much too small for any adult and would provide no effective airway management.

Question 367: The function of the Heidbrink meter in Boyle's machine is to:

A. Reduces pressure of gases
B. Indicates flow of gases (Correct Answer)
C. It is a fixed orifice meter
D. Indicates humidity of gases

Explanation: ***Indicates flow of gases*** - The **Heidbrink meter** is a type of **rotameter** designed to visibly indicate the **flow rate** of gases to the patient. - Its tapered tube and rotating bobbin allow the anesthesiologist to accurately monitor the **volume of gas** delivered. *Reduces pressure of gases* - **Pressure regulators** and **reducing valves** are responsible for reducing gas pressure from cylinders or pipelines, not the Heidbrink meter. - Flowmeters operate after pressure has been reduced to a safe and usable level. *It is a fixed orifice meter* - A Heidbrink meter is a **variable orifice flowmeter**, where the annular space around the bobbin changes with flow. - **Fixed orifice meters** rely on a constant opening and measure pressure differential across it to determine flow. *Indicates humidity of gases* - Devices like **hygrometers** or **humidifiers** are used to measure or add moisture to gases, respectively. - The Heidbrink meter's sole function is to display **gas flow**, not humidity.

Question 368: What are the present-day applications of oxygen concentrators?

A. Domiciliary use
B. Supplying ambulances
C. Supplying anesthesia machines
D. All of the options (Correct Answer)

Explanation: ***All of the options*** - Oxygen concentrators are versatile devices used in various medical settings due to their ability to provide a continuous supply of concentrated oxygen without the need for large, heavy oxygen tanks. - Their convenience, portability, and cost-effectiveness make them suitable for multiple applications, from home use to critical care transport and even as a source gas for anesthesia. *Domiciliary use* - Oxygen concentrators are widely used in **home care** settings for patients with chronic respiratory conditions like **COPD** or **pulmonary fibrosis**, who require long-term oxygen therapy. - They provide a continuous, on-demand supply of oxygen, reducing the need for frequent refills of oxygen cylinders. *Supplying ambulances* - Portable oxygen concentrators are increasingly used in **emergency medical services (EMS)** and during **patient transport** in ambulances. - They offer a lightweight and efficient oxygen source, crucial for immediate respiratory support during transit. *Supplying anesthesia machines* - Oxygen concentrators can be used to supply oxygen to **anesthesia machines**, especially in areas where piped medical gas systems are unavailable or unreliable. - They act as a **primary or backup source of oxygen** for mixing with anesthetic agents for patient ventilation during surgery.

Question 369: Bone marrow depression is seen with:

A. Ether
B. Isoflurane
C. Halothane
D. N2O (Correct Answer)

Explanation: ***N2O*** - **Nitrous oxide (N2O)** can cause **bone marrow depression** due to its interference with **vitamin B12 metabolism**. - Prolonged or repeated exposure to N2O **inactivates methionine synthase**, an enzyme crucial for **DNA synthesis** and **erythropoiesis**. *Ether* - **Ether** is an older anesthetic agent known for its **cardiovascular depression** and **irritating effects** on the respiratory tract. - It does not typically cause direct **bone marrow depression**. *Isoflurane* - **Isoflurane** is a volatile anesthetic that primarily affects the **cardiovascular system** by causing **vasodilation** and **myocardial depression**. - It is not associated with **bone marrow suppression**. *Halothane* - **Halothane** is a potent anesthetic that can cause **dose-dependent myocardial depression** and is known for its potential to induce **halothane hepatitis**. - **Bone marrow depression** is not a characteristic side effect of halothane.

Question 370: True about Rotameter:

A. Rotameter reading may not get affected by density inside the tube
B. The height to which bobbin rises indicates the flow rate (Correct Answer)
C. Rotameter reading may not get affected by static electricity
D. A rotameter is a variable pressure flowmeter

Explanation: ***The height to which bobbin rises indicates the flow rate*** - A rotameter is a **variable-area flowmeter** where the height reached by the bobbin directly correlates with the **flow rate** of the gas. - As gas flow increases, the **drag force** on the bobbin increases, causing it to rise higher in the tapered tube until the drag force equals the bobbin's weight. *Rotameter reading may not get affected by density inside the tube* - The **fluid density** significantly affects the rotameter reading, as the buoyant force and drag force depend on it. - Variations in **gas composition** or **pressure**, which change density, will alter the bobbin's position for a given flow rate. *Rotameter reading may not get affected by static electricity* - **Static electricity** can cause the bobbin in a rotameter to stick to the sides of the glass tube, leading to inaccurate readings. - This is particularly problematic with **dry gases** flowing through glass tubes. *A rotameter is a variable pressure flowmeter* - A rotameter is a **variable-area flowmeter**, meaning the cross-sectional area through which the fluid flows changes. - **Variable pressure flowmeters** (e.g., orifice plates) involve a constant flow area but a variable pressure drop.

Practice by Chapter

Anesthesia Machine Components

Practice Questions

Breathing Systems

Practice Questions

Vaporizers

Practice Questions

Gas Cylinders and Pipeline Supply

Practice Questions

Anesthesia Ventilators

Practice Questions

Standard Monitoring: ECG, BP, Pulse Oximetry

Practice Questions

Capnography

Practice Questions

Neuromuscular Monitoring

Practice Questions

Temperature Monitoring

Practice Questions

Invasive Hemodynamic Monitoring

Practice Questions

Equipment Troubleshooting

Practice Questions

Safety Features in Modern Anesthesia Equipment

Practice Questions

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