Manifestations of respiratory system dysfunctions

M. Tatar, J. Hanacek

Cardinal respiratory symptoms and signs

cough

sputum

dyspnea

wheezing

cyanosis

chest discomfort

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: dyspnea, wheezing

• lobar bronchi: asymptomatic or minor dyspnea

– peripheral aw: dyspnea

• Lung parenchyma ( or compliance): dyspnea

• Chest wall (abnormalities): dyspnea

• Respiratory muscles (fatigue): dyspnea

Disorders of airway defence mechanisms

Disorders of airways defence mechanisms

• Nasal cavity– sneezing

– nasal dyscharge

• Airways– Cough: acute respiratory infections, foreign body

aspiration, chronic bronchitis, chronic cough

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

Hyperplasia and hypertrophy of submucosal glands

Disorders of gas exchange

Disorders of gas exchange

Respiratory insufficiency (failure)

– Hypoxemic• Decreased ventilation/perfusion ratio• Venous admixture• Diffusion impairment

– Hypercapnic • Overall alveolar hypoventilation• Limits for hyperventilatory compensation of decreased ventilation/perfusion ratio

Vznik hypoxémie vplyvom zníženia V/Q pomeru

?

2 0 4 0 6 0 8 0 1 0 0 1 2 0 m m H gP a O 2

C

C

D

CA

C

B

C

2 0

1 0

Vol

% O

2

V yso k ý V ´A = 1 1/2

V ´A /Q ´

Q ´= 1 V ´A = 1/ 2 N ízk y

V ´A /Q ´

Q ´= 1

Fy z io lo g ic k ý V ´A /Q ´

V ´A = 1 V ´A = 1

Q ´= 1 Q ´= 1

’

Kompenzačné mechanizmy pri hyperkapnii

50

25

mmHg 20 4060

PaCO2

Vol

% C

O 2

B

A

C

Nízky V´A=2/3

V´A/Q´

Q ́= 1

V´A=11/3

Vysoký Q´=1V´A/Q´ Fyziologický V´A/Q´

Q´=1 V´A=1 V´A=1 Q´=1

11/3 + 2/3 = 2

P

Z

Disturbed regulation of breathing

Cheyne-Stokes respiration

Sleep apnea

Hyperventilation

Gasping

Hypopnea

Shortness of breath

Cheyne-Stokes breathing

General body responses

Fever

Weakness, fatigue

Decreased exercise tolerance

Immunity: eosinophilia

Weight loss: advanced disease

Cough

• Physiologic reflex

• Pathologic reflex

• Acute cough

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

Dyspnea

• Air hunger, chest tighness

• Subject´s feelings – needs for increased ventilatory activity

• Tachypnoea with either shallow or deep breathing

• Increased workload of respiratory muscles – normal gas

exchange cannot be achieved without increased ventilatory

effort

Pathophysiology of dyspnea

• Hyperventilation – acute hypoxemia

• Relative hyperventilation - decreased ventilatory surfice (atelectasis, pleural effusion, lung congestion, pneumotorax)

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

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

paralysis, myastenia gravis) - Limited chest movements (kyphoscoliosis)- !!! acute or chronic state; rest or physical activity

Causes of dyspnea

oxygen content in atmosphere

oxygen consumption during physical activity

Lung function disorders

Heart function disorders

Decreased hemoglobin content (during exercise)

Respiratory center dysfunction (Cheyne-Stokes, acidosis)

Stimulation of airway and lung nerve-endings (pneumonia, lung congestion)

Obesity

Emotive factors (chronic hyperventilatory syndrom)

Brain dysorders

Metabolic dysorders – hyperthyreosis

Hypoxemia

Tachycardia, tachypnea, dyspnea, mental status changes

Secondary polycythemia ( hematocrit)

Cyanosis

threshold for central cyanosis is a capillary reduced hemoglobin content of 5 g/dL

!!! ancillary nonspecific signs

Relation between SaO2 and arterial Hb

Cyanosis

• Central – hemiglobin – methemoglobin, sulphhemoglobin – hemoglobin - content of reduced Hb

• Heart disorders – lung congestion

• Lung disorders

– acute: pneumonia, lung edema

– chronic: COPD, severe lung fibrosis

• Peripheral– local perfusion disorders

• False– pigmentation (silver)

Peripheral and central cyanosis

Peripheral Central

Hypercapnia

Morning headaches

Papilledema, dilated conjunctival and superficial facial blood vessels

CO2 narcosis: anxiety may progress to delirium and

somnolency

Primary respiratory disorders can significantly affect the

function of other systems

Most frequently CVS

Cor pulmonale elevated jugular venous pulse, peripheral edema

Massive pulmonary embolism and tension pneumothorax circulatory shock – hypotension, weakness, pale, sweaty, oliguric, and develops impaired mentation

OSAS daytime sleepiness, right heart failure, systemic arterial hypertension