Pulmonary Function Testing (PFT) and History

Comprehensive vocabulary flashcards covering the history, indications, equipment, and diagnostic classifications of pulmonary function testing.

Spirometry

A fundamental pulmonary function test used to measure gas flows and volumes.

Hutchinson

The individual who in the 1800s developed the water-seal spirometer and recognized that Vital Capacity ($VC$) is directly related to a person's height.

Barach

A researcher in the 1930s who observed that patients with asthma or emphysema exhaled slower and developed the kymograph to detect airflow obstruction.

MVV

Maximum Voluntary Ventilation; a test developed by Cournand and Richards in 1941, originally referred to as Maximum Breathing Capacity ($MBC$).

$$FEV_{1.0}$$

Forced Exhaled Volume in $1$ second; used to assess airway obstruction. Healthy subjects should consistently exhale at least $80\%$ of their $FVC$ in this timeframe.

$$FEF_{25\%-75\%}$$

Previously known as Maximal Mid-expiratory Flow Rate ($MMFR$), this measure evaluates the airflow pattern between the $25\%$ and $75\%$ points of a Forced Vital Capacity ($FVC$).

Body Plethysmography

Commonly called a "body box," this equipment is used to measure total lung capacity ($TLC$), functional residual capacity ($FRC$), and airway resistance ($Raw$).

$$DLCO$$

Diffusing Capacity of the lung for Carbon Monoxide; a test used to measure the efficiency of gas distribution and exchange.

CBABE

An acronym representing the major obstructive lung diseases: Cystic Fibrosis, Bronchiectasis, Asthma, Bronchitis, and Emphysema.

Obstructive Defect

A pulmonary condition defined by an expiratory flow less than $80\%$ of the predicted value and a $TLC$ greater than $80\%$ if air trapping is present.

Restrictive Defect

A pulmonary condition characterized by lung volumes less than $80\%$ of the predicted value, found in conditions like scoliosis, obesity, or interstitial lung disease ($ILD$).

Bronchial Provocation Test

A diagnostic procedure used to assess airway hyperresponsiveness using agents like methacholine, histamine, or exercise.

Normal PFT Range

Generally defined as achieving $80\%$ to $120\%$ of the predicted values based on gender, height, age, and race.

Predicted Value Factors

The variables used to determine a patient's expected PFT results: Age, Sex, Standing Height, and Race. Height is the most important factor for predicting lung volumes.

PFT Patient Preparation

Requirements include withholding bronchodilators for $4-6$ hours, smoking cessation for at least $24$ hours, and avoiding large meals prior to testing.

Kymograph

A device used with dry-seal and water-seal spirometers to provide a graphic recording of lung volumes and flows.

Fixed Upper Airway Obstruction

A condition characterized by a flow-volume loop with flattened expiratory and inspiratory limbs.

Maximal Expiratory Flow Volume (MEFV) Curve

A graphic developed by Hyatt used to assess airway function, which later became the flow-volume loop when inspiratory flow was included.