Fundamental of mechanical VENTILATION

What is the primary driving force for airflow into the lungs during spontaneous inspiration?

• Increased intrapleural pressure

• Decreased alveolar pressure relative to atmospheric pressure

• Increased atmospheric pressure

• Decreased intrathoracic volume

According to the Hagen-Poiseuille equation, what is the most significant factor affecting airflow resistance in the airways?

• Airway length

• Airway radius

• Air viscosity

• Pressure gradient

What is the approximate alveolar oxygen partial pressure (PAO2) at sea level on room air (FiO2 = 0.21)?

• 40 mmHg

• 100 mmHg

• 150 mmHg

• 200 mmHg

In a patient with a high ventilation-perfusion (V/Q) mismatch, which of the following is most likely to occur?

• Hypercapnia with normal oxygenation

• Hypoxemia with normal CO2 levels

• Both hypercapnia and hypoxemia

• Normal gas exchange

Which oxygen delivery device can reliably deliver an FiO2 of 1.0 (100%)?

• Nasal cannula

• Simple face mask

• Non-rebreather mask

• Venturi mask

A patient requires an FiO2 of 0.35 with precise control. Which device is most appropriate?

• Nasal cannula at 4 L/min

• Venturi mask

• Partial rebreather mask

• High-flow nasal cannula (HFNC)

What is the maximum flow rate typically achievable with a high-flow nasal cannula (HFNC)?

• 15 L/min

• 30 L/min

• 60 L/min

• 100 L/min

What is the primary indication for initiating non-invasive ventilation (NIV) in acute respiratory failure?

• Severe hypoxemia unresponsive to high-flow oxygen

• Hypercapnic respiratory failure in COPD exacerbation

• Post-extubation prophylaxis in all patients

• Obstructive sleep apnea without acute failure

Which setting in bilevel positive airway pressure (BiPAP) primarily affects CO2 elimination?

• Inspiratory positive airway pressure (IPAP)

• Expiratory positive airway pressure (EPAP)

• Fraction of inspired oxygen (FiO2)

• Respiratory rate

What is a common complication of NIV that can be mitigated by proper mask fitting?

• Barotrauma

• Nasal bridge skin breakdown

• Ventilator-associated pneumonia

• Auto-PEEP