Cardiorespiratory Physiotherapy Flashcards

Practice vocabulary flashcards covering arterial blood gases, chest X-ray interpretation, ECG rhythms, lung volumes, and pulmonary function testing.

Partial Pressure

The contribution of one individual gas within a gas mixture to the total pressure; when a gas dissolves in liquid (blood), the amount dissolved depends on this pressure.

pH

The term used to express acidity or alkalinity, with a normal arterial blood range of $7.35 - 7.45$.

$$PaCO_2$$

The partial pressure of carbon dioxide in arterial blood, with a normal range of $35 - 45\,mmHg$; it is controlled by ventilation.

$$PaO_2$$

The partial pressure of oxygen in arterial blood, with a normal range of $80 - 100\,mmHg$.

$$FiO_2$$

The percentage of oxygen in the air breathed in; increasing this will improve the $PaO_2$ but will not reverse a rise in $PaCO_2$ in cases of inadequate ventilation.

$$SaO_2$$

The saturation of haemoglobin with oxygen, measuring the percentage of oxygen molecules bound to haemoglobin; normal value is $>95\%$.Ratio.

Oxyhaemoglobin Dissociation Curve

A curve representing the normal variation in the amount of oxygen that combines with Hb; its steep portion allows Hb to offload oxygen at the cellular level as $PaO_2$ falls.

Right Shift (Haemoglobin Affinity)

A shift in the dissociation curve meaning Hb unloads oxygen more easily; occurs during exercise, fever, or when blood is hypercapnic and acidic.

Hypoxaemia

Any state in which the $O_2$ content in arterial blood is reduced; clinical signs include restlessness, confusion, and increased heart rate.

Hypercapnia

Above-normal levels of carbon dioxide ($CO_2$) in the blood; clinical signs include a flapping tremor, warm extremities, and a bounding pulse.

Hypoxic Drive

A state where receptors become desensitized to $CO_2$ due to chronically high levels, causing the body to rely on $PaO_2$ as the principal ventilatory stimulus.

Buffer

Dissolved substances that stabilise pH by either providing (donating) or removing (accepting) $H^+$ from a solution.

Type 1 Respiratory Failure

Failure characterized by low $PaO_2$ ($<80\,mmHg$) with normal or low $PaCO_2$, implying defective oxygenation despite adequate ventilation.

Type 2 Respiratory Failure

Failure characterized by high $PaCO_2$ ($>50\,mmHg$) and usually low $PaO_2$, due to inadequate alveolar ventilation.

Posterio-anterior (PA) View

The optimum X-ray view for lungs where the beam passes from posterior to anterior; usually done erect to allow for full inspiration and to see fluid/gas levels.

RIP Mnemonic (CXR)

A mnemonic for technical adequacy of a Chest X-ray standing for Rotation, Inspiration (at least 6 anterior ribs above the diaphragm), and Penetration (exposure).

Consolidation

An X-ray finding where air-filled spaces are replaced with fluid, blood, or sputum.

Pneumothorax

A condition where air enters the pleural space, leading to a lack of lung markings on an X-ray and possible lung collapse.

P wave

The first positive deflection on an ECG representing atrial depolarisation.

QRS Complex

An ECG component representing the depolarisation of the ventricular contractile fibres.

T wave

An ECG component representing ventricular repolarisation.

Sinus Tachycardia

An acceleration of the SA node beyond its normal discharge rate, resulting in a heart rate $>100\,bpm$.

Atrial Fibrillation (AF)

Disorganised atrial electrical activity characterized by an unequal R-R length and fibrillating P waves.

Asystole

The absence of heart contraction, resulting in a rapid fall of blood pressure and requiring immediate CPR.

ST Elevation

An ECG abnormality where the ST segment is elevated, representing myocardial infarction.

Tidal Volume ($V_T$)

The volume of air that moves in or out of the lungs during normal quiet breathing.

Residual Volume (RV)

The volume of air that remains in the lungs after the Expiratory Reserve Volume ($ERV$) has been exhaled.

Vital Capacity (VC)

The total volume of air that can be exhaled after a maximal inspiration; calculated as $IRV + V_T + ERV$.

Functional Residual Capacity (FRC)

The total volume of air remaining in the lungs after a normal tidal exhalation ($ERV + RV$); helps maintain airway patency.

$$FEV_1$$

Forced Expiratory Volume in one second; a dynamic measurement reflecting the air forcefully expired in the first second of a maneuver.

Lower Limit of Normal (LLN)

The value corresponding to the 5th percentile of the healthy population (Z-score of $-1.65$); values below this suggest abnormal lung function.

Obstructive Lung Disease

Conditions making it difficult to expel air due to airflow limitation; indicated by an $FEV_1/FVC$ ratio below the LLN.

Restrictive Lung Disease

Conditions that reduce lung expansion and volumes; indicated by an $FVC$ below the LLN with a normal or increased $FEV_1/FVC$ ratio.

Peak Expiratory Flow (PEF)

A simple, effort-dependent measure of the maximum flow sustained for $10\,ms$ on forced expiration, measured in $L.min^{-1}$.

Wolff-Parkinson-White Syndrome

A cluster of abnormalities caused by additional muscle pathways between the atria and ventricles, enabling premature signals that increase heart rate.