Manifestations of respiratory system dysfunctions

M. Tatár

Cardinal respiratory symptoms and signs

cough

sputum

dyspnoea

wheezing

cyanosis

chest pain

Disorders of lung mechanics

Disorders of the lung mechanics

• Airway obstruction– nasal cavity: nasal congestion

– pharynx: collapse during sleep

– larynx: suffocation

– central aw:

• trachea: stridor

• main bronchi: dyspnoea, wheezing

• lobar bronchi: asymptomatic or minor dyspnoea

– peripheral aw: dyspnoea

• Lung parenchyma ( compliance): dyspnoea

• Chest wall (abnormalities): dyspnoea

• Respiratory muscles (fatigue): dyspnoea

Disorders of airway defence mechanisms

Disorders of airways defence mechanisms

• Nasal cavity– sneezing

– nasal discharge

• Airways– Cough: acute respiratory infections, foreign body

aspiration, chronic bronchitis, chronic cough

– Haemoptysis

– Expectoration - Sputum• mucoid (mainly macrophages) • purulent (neutrophils) • Pneumococcus - bloody or rust-colored • Pseudomonas, Haemophilus - green sputum

Hyperplasia and hypertrophy of submucosal glands

Cough

• Physiologic reflex

• Pathologic reflex

• Acute cough

• Chronic cough– Rhinitis/sinusitis– Asthma– Gastroesophageal reflux disease

Disorders of gas exchange

100 40

5050

PaO2

PaCO2

100%

70%chemoreceptors

ventilatory drive

120 30

hypoxemia

hypercapniahypoxemianormocapnia

SaO2

Disorders of gas exchange

Respiratory insufficiency (failure)

• Hypoxemic– Decreased ventilation/perfusion ratio– Venous admixture (right-to-left intrapulmonary shunt)– Diffusion impairment

• Hypercapnic– Overall alveolar hypoventilation– Critical amount of the compartments with low V´/Q´ ratio + limits

for hyperventilatory compensation

Hypoxemia

Tachycardia, tachypnea, dyspnoea, mental confusion and irritability

Secondary polycythemia ( hematocrit)

Cyanosis threshold for central cyanosis is a capillary reduced haemoglobin content of 50 g/L

!!! ancillary non-specific signs

Relation between SaO2 and arterial Hb

Cyanosis

• Central – haemiglobin – methemoglobin, sulphhemoglobin content of reduced haemoglobin

• Heart disorders – lung congestion

• Lung disorders

– acute: pneumonia, lung oedema

– chronic: COPD, severe lung fibrosis

• Peripheral– local perfusion disorders

• False– pigmentation (silver)

Central cyanosis

Hypercapnia

Morning headaches

Papilloedema, dilated conjunctival and superficial facial blood vessels

CO2 narcosis (rapid accumulation): anxiety may progress to delirium and somnolence

Disturbed regulation of breathing

Cheyne-Stokes breathing

Sleep apnoea

Hyperventilation (tetany)

Gasping

Hypopnoea

Cheyne-Stokes breathing

Dyspnoea - breathlessness

• Air hunger, awareness of the act of breathing, chest tightness

• Sensations: shortness of breath, feeling puffed, inability to get enough air, suffocation

• Subject´s feelings – needs for increased ventilatory activity; mechanical rather than chemical disturbances

• Tachypnoea with either shallow or deep breathing

• Increased workload of respiratory muscles – normal gas exchange cannot be achieved without increased ventilatory effort

Pathophysiology of dyspnoea

• Hyperventilation – acute hypoxemia

• Relative hyperventilation - decreased ventilatory surface (atelectasis, pleural effusion, lung congestion, pneumothorax)

• Disordered lung mechanics (most frequent cause)- Upper airways stenosis- Increased airways resistance = obstruction of peripheral airways

(asthma, COPD, heart failure)- Decreased muscle force (polyomyelitis, diaphragm paralysis,

myasthenia gravis) - Limited chest movements (kyphoscoliosis)

!!! acute or chronic state; rest or physical activity

Causes of dyspnoea

Oxygen content in atmosphere Oxygen consumption during physical activityLung function disordersHeart function disordersDecreased haemoglobin content (during exercise)Respiratory centre dysfunction (Cheyne-Stokes, acidosis) Stimulation of airway and lung nerve-endings (pneumonia, lung

congestion)ObesityEmotive factors (chronic hyperventilatory syndrome)Brain disordersMetabolic disorders – hyperthyroidism

Systemic non-respiratory responses

FeverWeakness, fatigueDecreased exercise toleranceImmunity: eosinophiliaWeight loss: advanced disease

Distant effects: finger clubbing and osteoarthropathy (periosteal overgrowth)

Primary respiratory disorders can significantly affect the

function of other systems

Most frequently CVS (the lung is the recipient of the entire cardiac

output through the lesser circulation)

• Cor pulmonale: elevated jugular venous pulse, peripheral oedema

• Massive pulmonary embolism and tension pneumothorax circulatory shock: hypotension, weakness, pallor, cold sweat, oliguria, and develops impaired mentation

• Obstructive sleep apnoea syndrome: daytime sleepiness, right heart failure, systemic arterial hypertension