DISEASES OF RESPIRATION PERIODIC BREATHING DEFINITION Periodic breathing

DISEASES OF RESPIRATION

PERIODIC BREATHING

DEFINITION • Periodic breathing is alternate deep & slight breathing style.

MECHANISM • When a person overbreaths, too much CO 2 is removed and extra O 2 is infused into the blood. When the pulmonary blood with more O 2 reaches brain, inhibits ventilation. Therefore when the respiratory center responds, it becomes depressed, and now opposite style begins. That is, CO 2 builds up & O 2 decreases in pulmonary blood. When this blood reaches the brain, results in rapid breathing.

CAUSES • 1. When there is a long delay in transport of blood from lungs to the brain, for example in severe cardiac failure. • 2. Increased negative feedback gain in the respiratory center. For example in patients with brain damage.

Respiratory diseases result from: • 1. Inadequate ventilation of lungs. • 2. Abnormalities of diffusion. • 3. Abnormalities of transport from the lung to the tissues.

The different methods for studying respiratory abnormalities are: • • 1. Study of blood gas & p. H. 2. Study of blood Pco 2. 3. Study of Po 2. 4. Measurement of maximum expiratory flow. 5. Study of pulmonary volumes. 6. Study of pulmonary capacities.

DEFINITION • Hypoxia is defined as the condition of reduced oxygen supply to the tissues, below normal requirement of the body.

CAUSES • 1. Inadequate oxygenation of lungs due to reduced ventilation or deficiency of O 2 in air, • 2. Pulmonary diseases causing hypoventilation or uneven ventilation-perfusion ratio. • 3. Venous shunts. • 4. Inadequate transport & delivery of O 2 e. g. , in anaemia. • 5. Inability of tissues to use O 2.

EFFECTS • 1. Depressed mental activity. • 2. Reduced work capacity of the muscles.

TYPES OF HYPOXIA • 1. Hypoxic hypoxia. • 2. Anaemic hypoxia. • 3. Circulatory hypoxia. • 4. Histologic hypoxia.

OXYGEN THERAPY IN DIFFERENT HYPOXIAS • 1. Placing the patient’s head in O 2 tent. • 2. Allowing the patient to breath high concentration of O 2. • 3. Administering oxygen through an intranasal tube.

HYPERCAPNIA

DEFINITION • Hypercapnia means excess CO 2 in the body fluids.

CAUSE • HYPERCAPNIA always results along with hypoxia. • So all causes of hypoxia may lead to hypercapnia.

CYNOSIS

DEFINITION • The term CYNOSIS means blueness of the skin

CAUSE • Its CAUSE is excessive amounts of deoxygenated hemoglobin in the skin blood vessels, especially in the capillaries.

CYNOSIS DEPENDS UPON • 1. Amount of deoxygenated hemoglobin in blood. • 2. Rate of blood flow. • 3. Skin thickness.

DYSPNEA • DYSPNEA is a feeling of inability to ventilate enough to satisfy the demand of air, although respiratory system is normal.