Disorders of Ventilation & Gas Exchange

GNUR 293; Vocabulary ONLY

Pneumonia

Inflammation of the lower respiratory tract (alveoli and bronchioles)

Community-Acquired Pneumonia (CAP)

Infection to the lower respiratory tract due to organisms found in the community

Hospital-Acquired Pneumonia (HAP)

Infection from organisms in the hospital

Aspiration Pneumonia

Inflammation of the lower respiratory tract due to food or liquid breathed into the lung

Ventilation and Perfusion Ratio Imbalance: High

Underperfused, alveolar unit is ventilated but not perfused.

Ventilation and Perfusion Ratio Imbalance: Low

Underventilated, airways are partially obstructed and related to hypoxemia. Airflow rates are low.

Ventilation and Perfusion Ratio Imbalance: Shunt

No ventilation, passage of deoxygenated blood from the right to the left side of circulation, either through anatomic shunting where blood bypasses the lungs from veins to arteries.

Tuberculosis

Infection of m. tuberculosis bacteria. Resistant to destruction and airborne.

Hypoxemia

Deficient blood oxygen as measured by low arterial O2 and low hemoglobin saturation

Hypoxic hypoxia

High altitude, hypoventilation, obstruction

Anemic hypoxia

Low hemoglobin

Circulatory hypoxia

Low cardiac output and shock

Histotoxic hypoxia

Decreased O2 carrying capacity due to toxic substance, cyanide poisioning

Hypoxic Vasoconstriction

Blood is diverted from areas of low alveolar oxygen to areas of higher oxygen

Primary Tuberculosis

Initial infection: Immune system traps bacteria and there are mild to no symptoms

Latent Tuberculosis

Silent infection; bacteria are dormant inside of granulomas and show no symptoms, contagiousness, but can reactivate

Obstructive Pulmonary Disorders

Characterized by airway obstructions that makes expiration difficult.

Pulmonary Function Testing

Measures lung volumes, airflow, and gas exchange

Forced Expiratory Volume in 1 Second (FEV1)

The amount of air a person can forcefully exhale in the first second of a breath

Forced Vital Capacity (FVC)

The total amount of air a person can forcefully exhale after a deep breath

FEV1/FVC Ratio

The percentage of FVC that is exhaled in the first second

>75% = normal

<70% = obstructive disease

Mild Obstruction FEV1/FVC Ratio

60%-70%

Moderate Obstruction FEV1/FVC Ratio

50%-60%

Severe Obstruction FEV1/FVC Ratio

<50%

Asthma

Airway obstruction (narrowing) that is sometimes reversible due to airway inflammation

Classic Asthma Triad

Wheezing, Dyspnea, Cough

Status Asthmaticus

Severe, life-threatening asthma attack. Unresponsive to usual bronchodilator treatment, leads to severe airway obstruction, respiratory failure, and hypoxia.

Asthma FEV1/FVC Ratio Diagnostic

< 70%

Reversibility Test Improvement Diagnostic

Improvement in FEV1 by >12% after a bronchodilator (indicates asthma)

Peak Expiratory Flow Rate (PEFR)

Measures airflow limitation

Chronic Obstructive Pulmonary Disease (COPD)

Progressive, irreversable lung disease that causes airflow limitation

Two main types of COPD

1. Type A—Emphysema “Pink Puffer”

2. Type B—Chronic Bronchitis “Blue Bloater

Type A COPD

Enlargement of the air space within the bronchioles and alveoli, alveolar destruction

Type B COPD

Chronic bronchitis, cough, excessive sputum

Chronic Bronchitis FEV1 and FVC ratio

Decreased FEV1 and FVC ratio, <70%

Atelectasis

Collapsing of alveoli in part or full lung

Obstructive Atelactasis

Atelactasis due to an obstruction in the airways, preventing air from reaching the alveoli

Compression Atelactasis

Atelactasis due to external pressure on the lung, causing it to collapse

Absorption Atelactasis

Atelactasis due to air unable to reach alveoli

Pneumothorax

Collapse of a lung or rupture of lung tissue caused by air leaking into the space between your lung and your chest wall

Spontaneous Pneumothorax

A collapsed lung caused by air leaking into the space between your lung and chest wall (the pleural space) without any physical injury or trauma

Traumatic Pneumothorax

Caused by penetrating or non-penetrating chest trauma injuries or CPR

Tension Pneumothorax

Pleural pressure exceeds atmospheric pressure