Group 2 MCQs - Ventilation

A 65-year-old male with chronic obstructive pulmonary disease (COPD) is admitted to the intensive care unit with acute exacerbation and respiratory failure. He is currently on mechanical ventilation.Which mode of ventilation is most appropriate for this patient to minimize the risk of barotrauma while allowing adequate CO2 clearance?

• Pressure control ventilation (PCV)

• Volume control ventilation (VCV)

• High-frequency oscillatory ventilation (HFOV)

• Non-invasive ventilation (NIV)

A 40-year-old woman with acute respiratory distress syndrome (ARDS) is intubated and requires mechanical ventilation. What initial ventilator setting is most appropriate to improve oxygenation while minimizing the risk of ventilator-induced lung injury?

• Low tidal volume ventilation (6 ml/kg of ideal body weight)

• High tidal volume ventilation (12 ml/kg of ideal body weight)

• Normal tidal volume ventilation (8-10 ml/kg of ideal body weight)

• High-frequency ventilation

A 72-year-old man with severe pneumonia is admitted to the ICU and placed on mechanical ventilation due to hypoxic respiratory failure.What ventilator adjustment might be necessary if the patient shows signs of increased work of breathing and desaturation?

• Increase the FiO2 (Fraction of Inspired Oxygen)

• Decrease the respiratory rate

• Increase the tidal volume

• Increase the PEEP (Positive End-Expiratory Pressure)

A normal 22year old man breathes in as much air as he can and then exhales as much air as possible. The lung volume at maximum inspiration is 6.0Litres, and the lung volume after maximum expiration is 1.0Litre. His tidal volume at rest is 0.5Liter, and his functional residual capacity is 3.5Litres. What is his vital capacity?

• 3.0 litres

• 3.5 litres

• 4.0 litres

• 5.0 litres

A 45-year-old man at sea level has an inspired oxygen tension of 149 mm Hg, nitrogen tension of

563 mm Hg, and water vapor pressure of 47 mm Hg. A small tumor pushes against a pulmonary blood vessel that completely blocks the blood flow to a small group of alveoli. What are the oxygen and carbon dioxide tensions of the alveoli that are not perfused (in mm Hg)?

• Carbon Dioxide - 0

  Oxygen - 0

• Carbon Dioxide - 0

  Oxygen - 149

• Carbon Dioxide - 40

  Oxygen - 104

• Carbon Dioxide - 47

  Oxygen - 149

• Carbon Dioxide - 45

  Oxygen - 149

If all other variables remain constant, which of the following is not true of the amount of fluid that would flow through a vessel?

• Doubling its length would result in half as much flow.

• Doubling the viscosity of the fluid would result in half as much flow.

• Doubling the radius of the vessel would result in 4 times more flow.

• Doubling the radius of the vessel would result in 16 times more flow.

When an individual is in the upright position, which of the following is true regarding the ventilation-perfusion ratio at rest?

• It would be evenly distributed throughout the lung.

• Alveoli at the top of the lung tend to be over-perfused and under-ventilated.

• Alveoli at the bottom of the lung tend to be over-perfused and under-ventilated.

• Alveoli in the middle portion of the lung are under-perfused and over-ventilated.

An athlete is running at an intensity that requires 100% of his VO2 max. The oxygen used by his respiratory muscles would be approximately _____% of his total oxygen uptake.

• 2

• 4

• 10

• 20

. You embark on a hiking trip on Mt. Kilimanjaro (altitude = 19,000 ft; Atmospheric air pressure = 379 mmHg).mHg). As you ascend, what are you likely to notice about your breathing?

• They would be at risk of alveolar collapse due to too much surface tension in the alveoli.

• You need to work harder to inhale, expanding your thoracic size beyond what is normal

• The haemoglobin molecules will have a higher affinity for oxygen as they pass by the biceps brachii compared to the gastrocnemius.

• Intrapleural pressure is greater than alveolar pressure.