Chap 42

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Transcript of Chap 42

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Disturbances of respiration

These are due to Abnormal respiratory

pattern Disturbances related to

respiratory gasses

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Abnormal respiratory pattern

Tachypnea … Increase rate of respiration..

Apnoea …Temporary cessation of breathing

Dyspnoea…distressed breathing Periodic breathing…alternate

periods of respiratory activity and apnea e.g. Cheyne stokes breathing

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Cheyne-Stokes Breathing

Is periodic type of breathing in which alternate periods of respiratory activity and apnoea occur at regular intervals

And during the period of respiratory activity there is waxing and waning of tidal volume

Duration is of 1 minute PO2 is lowest and the PCO2 is highest

at the end of apnoea.

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causes

PHYSIOLOGICAL CAUSES Voluntry hyperventilation High altitude During sleep PATHOLOGICAL CAUSES Chronic heart failure Brain damage Uraemia Poisoning by narcotics

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Sleep Apnea

Apnea is the temporary suspension of breathing.

Normally, some episodes of apnea occur. In people with sleep apnea, the episodes are longer and more frequent.

2 types of sleep apnea are: Obstructive sleep apnea

Central sleep apnea

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Obstructive Sleep Apnea In patients with sleep apnea, the pharynx

is collapsed while the muscles relax. Some of the factors that cause this collapse include: Excess fat deposits in the soft tissues of the

pharynx or fat masses in the neck. Nasal obstruction Enlarged tonsils Very large tongue Certain shapes of the palate

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Symptoms of Obstructive Sleep Apnea

Loud snoring and labored breathing that often progressively worsens.

Long silent periods (apnea) that cause increases in PCO2 and decreases in PO2.

This stimulates respiration, which results in loud snorts and gasps.

This repeats.

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Central Sleep Apnea

Less common than obstructive sleep apnea.

The CNS signal to the respiratory muscles stops.

Can be caused by damage to the central respiratory center or respiratory neuromuscular junction.

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Disturbances related to respiratory gases Respiratory disturbances are

related to respiratory gases include

Hypoxia Hypercapnia Asphyxia Carbon monoxide poisoning

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HypoxiaTissue hypoxia means

that the amount of oxygen available for cellular metabolism is inadequate.

Hypoxia leads to anaerobic mechanisms that eventually produces lactic acid and cause the blood pH to decrease.

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CAuses Decreased oxygen tension of the arterial blood Decreased oxygen carrying capacity

of lungs Decreased rate of blood flow to the

tissues Decreased tissue utilization of

oxygen

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types Hypoxic hypoxia Anemic hypoxia Circulatory hypoxia Histotoxic hypoxia

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Hypoxic Hypoxia Hypoxic hypoxia or hypoxemic hypoxia

refers to the condition in which the PO2 is abnormally low.

This form of hypoxia is better known as hypoxemia (low oxygen concentration in the blood).

This form of hypoxia can develop from: pulmonary shunting - low alveolar

PO2 diffusion impairment - V/Q mismatch

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Anemic Hypoxia Anemic hypoxia is when the oxygen

tension in the arterial blood is normal, but the oxygen-carrying capacity of the blood is inadequate.

This form of hypoxia can develop from: a low amount of Hb in the blood a deficiency in the ability of Hb to carry

O2 Increased cardiac output is the main

compensatory mechanism for anemic hypoxia. 16

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Circulatory Hypoxia

In circulatory hypoxia, the arterial blood that reaches the tissue cells may have a normal O2 tension and content, but the amount of blood--and therefore the amount of O2--is not adequate to meet tissue needs.

The two main causes of circulating hypoxia are: stagnant hypoxia arterial-venous shunting

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Histotoxic Hypoxia

Histotoxic hypoxia develops in any condition that impairs the ability of tissue cells to utilize oxygen.

May be due to cyanide or sulphide poisoning

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Characteristic features of hypoxia

Features Hpoxic hypoxia

Anemic hypoxia

Circulatory hypoxia

Histotoxic hypoxia

PO2 in arterial blood

Reduced

Normal Normal Normal

O2 carrying capacity of blood

Normal Reduced

Normal Normal

Velocity of blood flow

Normal Normal Reduced Normal

Utilization of blood flow

Normal Normal Normal Reduced

Efficiency of O2 therapy

100% 75% >50% Not useful

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Cyanosis

Cyanosis is the term used to describe the blue-gray or purplish discoloration seen on the mucous membranes, fingertips, and toes whenever the blood in these areas is hypoxemic.

When level of deoxy Hb ≥5g/dl signs of cyanosis may develop

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Types of hypoxia

Peripheral cyanosis Central cyanosis

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Treatment of cyanosis

Warming of the affected areas Peripheral cyanosis brought about by

exposure to cold or Raynaud’s phenomenon may be treated symptomatically using gentle warming of the fingers and toes.

Oxygenation as a treatment for cyanosis Initial stabilization requires oxygenation.

Sometimes a breathing machine or ventilator might be required.

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Surgery as a treatment for cyanosis Treatment of central cyanosis due to

congenital heart defects may often involve surgery.

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Asphyixa

Refers to the condition in which there is hypoxia associated with hypercapnia

May be due to strangulation drowning tracheal obstruction due to foreign body paralysis of diaphragm

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treatment

First aid to remove foreign body Emergency resuscitation Expired Air Resuscitation (EAR) Cardio-Pulmonary Resuscitation

(CPR)

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pneumonia

Inflammatory condition of the lung in which alveoli are filled with fluid and blood cells

There is hypoxemia and hypercapnea

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treatment

Most cases of pneumonia can be treated at home. However babies, children, and people with severe pneumonia may need to be admitted to hospital for treatment.

Pneumonia is usually treated with antibiotics, even if viral pneumonia is suspected as there may be a degree of bacterial infection as well. The type of antibiotic used and the way it is given will be determined by the severity and cause of the pneumonia.

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asthma

Asthma is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm.

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Treatment

Bronchodilators Nebulization

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tuberculosis Tuberculosis) is a

common infectious disease caused by various strains of mycobacteria, usually Mycobacterium tuberculosis. Tuberculosis typically attacks the lungs, but can also affect other parts of the body

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Symptoms of TB

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Treatment

Anti tuberculous drugs

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