Pulmonary Function Flashcards

Flashcards on Pulmonary Function, Volumes, and Capacities

Functions of the respiratory or pulmonary system

Supplying oxygen (O2) during inhalation, removing carbon dioxide (CO2) during exhalation, and adjusting the acid-base balance (pH) of the body by removing acid-forming CO2.

Important tools in assessing the health and capacities of a person

Measurement of lung volumes and the rate of air movement (airflow).

Tidal Volume (TV)

The amount of air involved in one normal inhalation and exhalation; average is 500 mL.

Minute Respiratory Volume (MRV)

The amount of air inhaled and exhaled in 1 minute; calculated by multiplying tidal volume by the number of respirations per minute.

Inspiratory Reserve Volume (IRV)

The amount of air, beyond tidal volume, that can be taken in with the deepest possible inhalation; normal range is 2000 to 3000 mL.

Expiratory Reserve Volume (ERV)

The amount of air, beyond tidal volume, that can be expelled with the most forceful exhalation; normal range is 1000 to 1500 mL.

Residual Air (RV)

The amount of air that remains in the lungs after the most forceful exhalation; the average range is 1000 to 1500 mL. Ensures some air remains in the lungs for continuous gas exchange.

Alveolar Ventilation

The amount of air that actually reaches the alveoli and participates in gas exchange.

Anatomic Dead Space

The air still within the respiratory passages that does not participate in gas exchange; normal volume is 100 to 150 mL.

Physiological Dead Space

The volume of non-functioning alveoli that decrease gas exchange; causes include bronchitis, pneumonia, tuberculosis, emphysema, asthma, pulmonary edema, and a collapsed lung.

Inspiratory Capacity (IC)

Tidal volume plus the inspiratory reserve volume; approximately 3500 mL.

Functional Residual Capacity (FRC)

Expiratory reserve volume plus the residual volume; the volume remaining in the lungs after a normal tidal volume is expired, approximately 2400 mL.

Vital Capacity (VC)

Inspiratory capacity plus the expiratory reserve volume, or the volume that can be expired after maximal inspiration; approximately 4700 mL.

Total Lung Capacity (TLC)

All of the lung volumes combined: vital capacity plus the residual volume, or 5900 mL.

Tiffneau Index

Represents the proportion of a person's vital capacity that they are able to expire in the first second of forced expiration; also called the bronchial permeability index; normally it must be over 80%.

Helium Dilution

A method used to measure Functional Residual Capacity (FRC).

Forced Vital Capacity (FVC)

Maximal amount of air that a person can forcibly exhale after a maximal inhalation.

Forced Expiratory Volume (FEV)

Percentage of FVC that a person forcibly expels in intervals of 1, 2, and 3 seconds (FEV1.0, FEV2.0, FEV3.0).

Maximal Voluntary Ventilation (MVV)

Maximum ventilated flow per minute; the volume of air circulated within one minute by forced breathing; Average normal values, F - 100-120l/min M: 110-130 l/min.

Spirometer

Instrument used to measure the volume of air a person inhales and exhales.

Preparation before spirometry procedure

Avoid alcohol consumption 4 hours before, heavy meals 2 hours before, smoking an hour before and intense exercise 30 minutes before.

Clinical significance of ventilatory function tests

Help to determine the degree of impairment of ventilatory function, diagnose lung diseases and evaluate ventilatory function before a surgical intervention.

OBSTRUCTIVE VENTILATORY DYSFUNCTION (OVD)

FEV reduced < 80 % from ideal FEV, Tiffneau index reduced < 70-80 % and normal VC.

RESTRICTIVE VENTILATORY DYSFUNCTIONS (RVD)

VC reduced < 80% from ideal VC and Tiffneau index normal or increased > 70-80%.

MIXED VENTILATORY DYSFUNCTIONS

VC < 80% and Tiffneau index < 70%.