Deck 1: Principles of Mechanical Ventilation

Question 1

When a patient fails to ventilate or oxygenate adequately, the problem is caused by pathophysiological factors such as hyperventilation.

Answer 1

False

Question 2

One of the most common causes of increased airway resistance is COPD.

Answer 2

True

Question 3

Airway resistance varies directly with the diameter of the airway or ET tube and inversely with the length.

Answer 3

False

Question 4

Low compliance measurements are usually related to conditions that increase the patient's functional residual capacity and total lung capacity.

Question 5

When looking at the pressure-volume loop, a shift of the slope toward the pressure axis indicates a decrease in compliance.

Question 6

One of the most frequent uses of mechanical ventilation is for the management of postoperative patients recovering from ____.

A) apnea and impending respiratory arrest
B) anesthesia and medications
C) acute severe asthma and heart failure
D) acute brain injury and flail chest

Question 7

Normal airway resistance in healthy adults is between 0.5 to ____ cm H₂O/L/sec.

A) 1.5
B) 2.0
C) 2.5
D) 3.0

Question 8

Based on Poiseuille's Law, the work of breathing increases by factor of ____ when the radius (r) of the airway is reduced by half its original size.

A) 8-fold
B) 10-fold
C) 13-fold
D) 16-fold

Question 9

____ occurs when the patient's minute ventilation cannot keep up with CO₂ production.

A) Ventilatory failure
B) Refractory hypoxemia
C) Oxygenation failure
D) Deadspace ventilation

Question 10

Which of the following is calculated by C = DV/DP?

A) oxygenation failure
B) static compliance
C) dynamic compliance
D) lung compliance

Question 11

For critically-ill patients, the dynamic compliance is between 30 and ____ mL/cm H₂O.

A) 40
B) 50
C) 60
D) 70

Question 12

For critically-ill patients, the static compliance is between 40 and ____ mL/cm H2O.

A) 50
B) 60
C) 70
D) 80

Question 13

Which of the following is defined as wasted ventilation, or a condition in which ventilation is in excess of perfusion?

A) ventilatory failure
B) deadspace ventilation
C) refractory hypoxemia
D) oxygenation failure

Question 14

____ occurs when the ventilated alveoli are not adequately perfused by pulmonary circulation.

A) Alveolar deadspace
B) Anatomic deadspace
C) Physiologic deadspace
D) Arterial deadspace

Question 15

Hypercapnia, which involves an increase in ____, is the key feature of ventilatory failure.

A) PCO₂
B) PIO2
C) F_IO₂
D) PaCO₂

Question 16

Which of the following is the difference between tidal volume and deadspace volume?

A) minute alveolar ventilation
B) alveolar volume
C) (V/Q) ratio
D) physiologic deadspace

Question 17

The gas diffusion coefficient for carbon dioxide is ____ times greater than that for oxygen.

A) 10
B) 14
C) 17
D) 19

Question 18

The classic physiologic shunt equation ____.

A) requires only an arterial blood sample
B) requires an arterial blood sample and a mixed venous blood sample
C) requires only a venous blood sample
D) does not require a blood sample

Question 19

Which of the following is a clinical example of a condition that may lead to ventilatory pump failure?

A) emphysema
B) hyperkalemia
C) pulmonary embolism
D) COPD

Question 20

Regardless of the diagnosis or disease state, patients who require mechanical ventilation generally have developed _______________, oxygenation failure, or both.

Question 21

In mechanical ventilation, the degree of airway resistance is primarily affected by the length, size, and patency of the airway, endotracheal tube, and _______________.

Question 22

In a clinical setting, _______________ may result if the patient is unable to overcome the airway resistance by increasing the work of breathing.

Question 23

A(n) _______________ bowing of the P-V loop suggests an overall increase in airflow resistance.

Question 24

In a clinical setting, acute respiratory distress syndrome (ARDS) and _______________ are two causes of increased work of breathing.

Question 25

When a patient fails to ventilate or oxygenate adequately the problem may be caused by one of six major pathophysiological factors. List these factors.

Question 26

Outline the method used to measure static and dynamic compliance.

Question 27

Assessment of compliance can be divided into static compliance and dynamic compliance measurements. Explain the relationship and clinical significance of these measurements.

Question 28

Define deadspace ventilation and describe the three different types of deadspace.

Question 29

What are the five mechanisms that lead to the development of ventilatory failure?