Anesthetic Equipment and Monitoring — MCQs
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The device shown can deliver FiO2 up to ____ :
The pin index of the following cylinder is:
The pin index of the following cylinder is:
The following capnographic tracing shows:
The following capnographic tracing represents:
The following capnographic tracing is seen in:
The following capnography recording indicates:
What is the next best step in patient with the following capnography tracing?
The image shows capnography recording. Et CO2 is measured at:
What does the marking $X$ at endotracheal tube indicate? (Recent NEET Pattern 2016-17)
Anesthetic Equipment and Monitoring Indian Medical PG Practice Questions and MCQs
Question 291: The device shown can deliver FiO2 up to ____ :
- A. 40%
- B. 60%
- C. 80%
- D. 100% (Correct Answer)
Explanation: ***100%*** - Oxygen hoods, as pictured, are designed to deliver a specific and controlled **fraction of inspired oxygen (FiO2)** directly around an infant's head. - They allow for the delivery of **pure oxygen (100%)**, often mixed with air to achieve the desired FiO2, which can be monitored very closely for neonatal respiratory support.
Question 292: The pin index of the following cylinder is:
- A. 1,5
- B. 2,5 (Correct Answer)
- C. 3,5
- D. 1,6
Explanation: ***2,5*** - The image displays a **blue gas cylinder**, which commonly indicates that it contains **nitrous oxide**. - According to the **Pin-Index Safety System**, the pin-index for nitrous oxide cylinders is **2 and 5**. *1,5* - The combination of **1 and 5** is typically associated with **medical air** cylinders. - This cylinder is blue, indicating nitrous oxide, not medical air. *3,5* - The pin index of **3 and 5** is designated for **nitrogen gas**. - The color of the cylinder (blue) does not correspond to nitrogen. *1,6* - The pin index of **1 and 6** is typically designated for **carbon dioxide** cylinders. - The cylinder's color and the intended gas (nitrous oxide) do not match this pin index.
Question 293: The pin index of the following cylinder is:
- A. 1,5
- B. 2,5 (Correct Answer)
- C. 3,5
- D. 7
Explanation: ***2,5*** - The image displays a gas cylinder with a **pin index safety system** where pins are evident at positions 2 and 5. This specific pin configuration is standard for **nitrous oxide** cylinders. - The pin index system for medical gases is designed to prevent incorrect gas connections, ensuring that only the proper regulator can be attached to a specific gas cylinder. *1,5* - A pin index of 1,5 is associated with **oxygen** cylinders. The cylinder in the image has a different pin configuration, which indicates it does not contain oxygen. - The physical appearance and color coding (blue body with a white shoulder/top, though not clearly visible in this image other than the body color) of this cylinder are not consistent with oxygen. *3,5* - A pin index of 3,5 is designated for **air** cylinders. The pin configuration in the image does not match this setting. - Each medical gas has a unique and standardized pin index combination to ensure safety and prevent medical errors. *7* - A single pin at position 7 is associated with **carbon dioxide** cylinders. The cylinder in the image clearly shows two pins, not one. - The pin index system relies on precise hole and pin placement to achieve gas-specific connections.
Question 294: The following capnographic tracing shows:
- A. Multiple rebreathing (Correct Answer)
- B. Cardiogenic oscillations
- C. Bronchospasm
- D. Normal capnography
Explanation: ***Multiple rebreathing*** - The **multiple oscillations** in the expiratory plateau (phase 3) indicate that the patient is repeatedly rebreathing exhaled gases, which are incompletely flushed from the breathing system. - This pattern is often due to **inadequate fresh gas flow** in a semi-open or non-rebreathing circuit, or a malfunctioning expiratory valve allowing exhaled CO2 to return into the inspiratory limb.
Question 295: The following capnographic tracing represents:
- A. Endobronchial intubation
- B. Pregnancy
- C. Esophageal intubation
- D. Malfunction of carbon dioxide rebreather system (Correct Answer)
Explanation: ***Malfunction of carbon dioxide rebreather system*** - The capnograph shows a **progressive increase in baseline CO2** and an increasing end-tidal CO2 (ETCO2) from 40 to 47 mmHg, indicating a buildup of CO2 due to inadequate CO2 removal. - This pattern is characteristic of a malfunctioning rebreather system, such as **exhausted soda lime** in an anesthetic circuit, where exhaled CO2 is not effectively absorbed. *Endobronchial intubation* - Endobronchial intubation typically results in **unilateral breath sounds** and can cause a decrease in ETCO2 due to reduced effective alveolar ventilation. - It does not typically lead to a progressively increasing baseline CO2 or ETCO2 in the manner shown, as CO2 exchange is still occurring, just less efficiently. *Pregnancy* - Pregnancy is associated with a **physiologic decrease in ETCO2** due to increased tidal volume and respiratory rate, leading to chronic hyperventilation to facilitate CO2 transfer to the fetus. - It would not cause a rising baseline CO2 or an increasing ETCO2 as depicted in the tracing. *Esophageal intubation* - Esophageal intubation is characterized by the **absence of a sustained capnograph waveform**, as no significant CO2 is exhaled from the esophagus. - A transient, small amount of CO2 may be detected initially from gastric CO2, but it quickly drops to zero, which is distinctly different from the waveform shown.
Question 296: The following capnographic tracing is seen in:
- A. Endobronchial intubation
- B. Pregnancy
- C. Esophageal intubation
- D. Curare cleft (Correct Answer)
Explanation: ***Curare cleft*** - The capnography tracing shows an abrupt **dip or 'cleft'** in the plateau phase, which is characteristic of a 'curare cleft' or 'window' on the capnogram. This occurs when the effect of **muscle relaxants (like curare)** starts to wear off, and the patient attempts to breathe spontaneously against a ventilator. - The spontaneous inspiratory effort causes a temporary decrease in **CO2 delivery to the airway**, leading to the characteristic dip in the capnogram. *Endobronchial intubation* - Endobronchial intubation typically results in a **reduced tidal volume** to the non-occluded lung and increased dead space ventilation in the occluded lung, but it does not cause this specific "cleft" morphology. - The capnogram might show a **gradual decrease in end-tidal CO2 (ETCO2)** due to ventilation-perfusion mismatch, but not an abrupt dip. *Pregnancy* - Pregnancy leads to various physiological changes, including an **increase in minute ventilation** and a **decrease in arterial PCO2 (PaCO2)**. - The capnogram in a pregnant patient would likely show a **lower baseline ETCO2** due to hyperventilation but would not exhibit a 'curare cleft'. *Esophageal intubation* - Esophageal intubation is characterized by the **absence of CO2** or very low, inconsistent CO2 readings on the capnogram, as the esophagus does not contain significant CO2. - The trace would appear as a **flat line or show minimal, erratic CO2 fluctuations**, clearly distinct from the described curvilinear pattern with a dip.
Question 297: The following capnography recording indicates:
- A. Pulmonary embolism
- B. Bronchospasm
- C. Esophageal intubation
- D. Curare cleft (Correct Answer)
Explanation: ***Curare cleft*** - The image displays a prominent "curare cleft" or "wagon wheel" pattern, which is a dip in the plateau phase of the capnograph waveform. - This cleft indicates the spontaneous **respiratory efforts** of a patient who is not adequately paralyzed or whose muscle relaxant is wearing off. *Pulmonary embolism* - A pulmonary embolism typically causes a sudden decrease in **end-tidal CO2 (EtCO2)** due to increased dead space, leading to a lower plateau, but not a "cleft" pattern. - The waveform would show a flat plateau at a lower CO2 value with an increased alpha angle. *Bronchospasm* - Bronchospasm results in an **obstructive pattern** on the capnogram, characterized by a **prolonged expiratory phase** and a "shark fin" appearance, where the ascending limb is steep, and the alveolar plateau is sloped. - It does not present as a dip in the plateau phase. *Esophageal intubation* - Esophageal intubation would result in a **flatline capnograph** or very small, sporadic waveforms, because no CO2 is being exhaled from the lungs. - The waveform in the image clearly shows significant CO2 exhalation, ruling out esophageal intubation.
Question 298: What is the next best step in patient with the following capnography tracing?
- A. Check for position of endotracheal tube (Correct Answer)
- B. Check for connections of anesthesia machine
- C. Change the soda lime canister
- D. Give skeletal muscle relaxant
Explanation: ***Check for position of endotracheal tube*** - The "curare cleft" or re-curarization pattern on the capnography indicates that the patient is spontaneously breathing against the ventilator, suggesting the effects of **muscle relaxants are wearing off**. - This pattern can also indicate a partially obstructed or dislodged endotracheal tube, where the patient's spontaneous breaths against the obstruction cause a dip in the expiratory plateau. Therefore, checking the **endotracheal tube position** is a critical immediate step. *Check for connections of anesthesia machine* - While machine connections are important for proper ventilation, this specific **"curare cleft" pattern** is more indicative of patient respiratory effort or tube issues rather than a primary machine connection problem. - A machine connection issue would typically manifest as a **loss of waveform** or an abnormal overall shape, not specifically a dip in the expiratory plateau. *Change the soda lime canister* - A depleted soda lime canister causes an **elevation of the baseline** (inspire CO2 not zero) and a rise in end-tidal CO2, as CO2 is not effectively reabsorbed. - This capnography tracing does not show an elevated baseline, making a depleted soda lime canister an **unlikely cause** of the observed "curare cleft." *Give skeletal muscle relaxant* - While the "curare cleft" can indicate that the effects of muscle relaxants are waning and the patient is beginning to spontaneously breathe, the **immediate next step** is to ensure airway patency and security. - Administering a muscle relaxant without first checking the **airway and tube position** could mask a serious issue. Re-dosing relaxants might be considered after ensuring the airway is secure and the tube is correctly positioned if the patient's spontaneous breathing is detrimental.
Question 299: The image shows capnography recording. Et CO2 is measured at:
- A. Point A
- B. Point B
- C. Point C
- D. Point D (Correct Answer)
Explanation: ***At point D*** - This point represents the **end-tidal CO2 (EtCO2)**, which is the maximum concentration of CO2 at the end of exhalation. - The capnogram displays CO2 concentration over time, and point D is the peak of the CO2 waveform for that breath cycle, indicating the CO2 level just before inspiration begins.
Question 300: What does the marking $X$ at endotracheal tube indicate? (Recent NEET Pattern 2016-17)
- A. Vocal cord marker (Correct Answer)
- B. Murphy's eye
- C. Inflatable cuff
- D. Lanz pressure regulating valve
Explanation: ***Vocal cord marker*** - The **"X" mark** on the endotracheal tube indicates the position that should ideally be aligned with the **vocal cords** upon successful intubation. - This helps in positioning the tube correctly within the trachea, ensuring the cuff is seated below the vocal cords but above the carina, preventing airway trauma and optimizing ventilation. *Murphy's eye* - The **Murphy's eye** is a hole located at the **distal tip** of the endotracheal tube, opposite the main bevel. - It serves as a safety feature to allow for ventilation even if the main opening of the tube becomes occluded. *Inflatable cuff* - The **inflatable cuff** is a balloon-like structure located near the distal end of the endotracheal tube, which, once inflated, **seals the airway** to prevent air leakage and aspiration. - The image shows the cuff inflated, but "X" points to a specific marking on the tube, not the cuff itself. *Lanz pressure regulating valve* - The **Lanz pressure regulating valve** is a device used to automatically maintain a safe and constant pressure in the endotracheal tube cuff, preventing over-inflation and reducing the risk of tracheal damage. - It is typically a separate component connected to the pilot balloon line, not a marking on the tube itself.
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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