Deck 2: Effects of Positive Pressure Ventilation

Question 1

During spontaneous ventilation, the diaphragm and other respiratory muscles create gas flow by raising the pleural, alveolar, and airway pressures.

Answer 1

False

Question 2

Positive pressure ventilation causes an increase in intrathoracic pressure and compression of the pulmonary blood vessels leading to an overall decrease in ventricular output, stroke volume, and pressure readings.

Answer 2

True

Question 3

Oliguria is defined as urine output < 400 mL in 24 hours (or <160 mL in 8 hours).

Answer 3

True

Question 4

The caloric cost of breathing for COPD patients is about 10 times that of normal individuals because of the increased work of breathing necessary to overcome the high airway resistance and V/Q abnormalities.

Question 5

Sustained hyperventilation of less than 24 hours causes respiratory alkalosis and increases cerebral blood flow and intracranial pressure.

Question 6

Under normal conditions, the ____ and tidal volume are directly related in positive pressure ventilation.

A) airflow resistance
B) pressure gradient
C) alveolar pressure
D) airway pressure

Question 7

Positive pressure ventilation increases ____ and decreases cardiac output.

A) PIP
B) PEEP
C) mPaw
D) P_I

Question 8

A decreased venous return (or filling of ventricles) leads to a reduction in ____.

A) intrathoracic pressure
B) stroke volume
C) compression of pulmonary vessels
D) stroke volume and cardiac output

Question 9

During mechanical ventilation, ____ is not affected to a great extent because of the capability of the systemic venous circulation to compensate or regulate changing blood pressure and volume.

A) pulmonary capillary wedge pressure
B) pulmonary artery pressure
C) stroke volume
D) cardiac output

Question 10

Which of the following is important for eliminating wastes, clearance of certain drugs, and regulating fluid, electrolyte, and acid-base balance?

A) intestine
B) lungs
C) kidneys
D) liver

Question 11

Which of the following is a drug that is eliminated by tubular secretion?

A) digoxin
B) vancomycin
C) furosemide
D) phenobarbital

Question 12

____ dysfunction may be monitored by measuring the prothrombin time and bilirubin and albumin levels.

A) Liver
B) Kidney
C) Cardiovascular
D) Gastrointestinal

Question 13

Which of the following is an effect of PEEP and increased intra-abdominal pressure?

A) decreased atelectasis
B) decreased functional residual capacity
C) increased compliance of ventricles
D) increased cardiac output

Question 14

____ is an example of a nonmechanical cause of muscle fatigue that may lead to ventilatory failure.

A) Low chest wall compliance
B) Low lung compliance
C) Malnutrition
D) High airway resistance

Question 15

Energy requirements for critically ill patients are normally computed by using the Harris-Benedict equation. This equation estimates the resting energy expenditure (REE) based on weight, height, age, and ____.

A) additional metabolic needs
B) gender
C) stress factor
D) degree of infection

Question 16

When TPN is used, it is essential to keep the amount of dextrose, a(n) ____, to a minimum as it can cause lipogenesis and increase O₂ consumption and CO₂ production.

A) carbohydrate
B) amino acid
C) fat
D) electrolyte

Question 17

Carbon dioxide acts as a vasodilator in ____ blood vessels.

A) hepatic
B) renal
C) gastrointestinal
D) cerebral

Question 18

Which of the following is a neurologic change associated with hypoxemia?

A) increased cerebral blood flow
B) increased intracranial pressure
C) decreased mental and motor functions
D) impaired cerebral metabolism

Question 19

During positive pressure ventilation, pressures measured in the ____, left atrium, pulmonary artery, and right atrium are slightly higher than those measured during spontaneous ventilation.

A) aorta
B) superior vena cava
C) pulmonary veins
D) left ventricle

Question 20

Which of the following is a pathophysiologic change associated with short-term (<24 hours) hyperventilation?

A) leftward shift of oxyhemoglobin curve
B) reduced O₂ release to tissues
C) cerebral tissue hypoxia
D) decreased cerebral blood flow

Question 21

In _______________, the level of positive pressure is dependent on the mechanical tidal volume, as well as the patient's compliance and airflow resistance.

Question 22

During pressure-controlled ventilation, the peak inspiratory pressure (PIP) is preset according to the estimated _______________ requirement of a patient.

Question 23

Mean airway pressure is a function of _______________, respiratory frequency, peak inspiratory pressure, and positive end-expiratory pressure.

Question 24

When _______________ is added to mechanical ventilation, the blood flow to the liver is noticeably reduced.

Question 25

GI complications may be caused by a(n) _______________ of perfusion to the GI tract and medications that are commonly used in mechanically ventilated patients.

Question 26

Compare continuous positive airway pressure (CPAP) and positive end-expiratory pressure PEEP.

Question 27

Describe the relationship between PEEP and hepatic perfusion.

Question 28

Explain why adequate nutritional support is essential in the management of critically ill patients.

Question 29

Outline some indicators of neurologic impairment due to ventilatory and oxygenation failure?

Question 30

Discuss a few indicators of renal failure.