Respiratory System Disorders - 3

Question 1

Restrictive lung disorders

Answer 1

Group of diseases
Lung expansion is impaired and total lung capacity is reduced
Obstructive and restrictive
Abnormality of the chest wall limits lung expansion - kyphosis or scoliosis - affecting the thorax), poliomyelitis or amyotrophic lateral sclerosis or botulism, or muscular dystrophy
Lung disease impairs expansion
Idiopathic pulmonary fibrosis
Inhaled irritants
Loss of elastic fibers and fibrosis in chronic conditions

Question 2

Pneumoconioses

Answer 2

Chronic restrictive diseases resulting from long-term exposure to irritating particles such as asbestos, silica, coal dust, fungal spores.
Inflammation and fibrous tissue develop, destruction of connective tissue, immune response, compliance is lost
Lung cancer
Onset is insidious, dyspnea occurs first, increasing effort required to breath.

Question 3

Pulmonary edema

Answer 3

Fluid collecting in the alveoli and interstitial area, reduces oxygen diffusion and lung expansion
Develops when:
Inflammation is present in the lungs increasing capillary permeability
Plasma protein levels are low increasing plasma osmotic pressure
Pulmonary hypertension develops
When hydrostatic pressure in the pulmonary capillaries becomes high like with congestive heart failure this leads to a shift of fluid out of the capillaries and into the alveoli
Hypoxemia
interferes with surfactant, leads to difficulty in expanding the lungs, capillaries may rupture

Question 4

Causes of pulmonary edema

Answer 4

Left-sided congestive heart failure, backup of blood causes high pressure in pulmonary circulation, chronic or acute
Hypoproteinemia due to kidney and liver disease
Inflammation in lungs - increased capillary permeability
Blocked lymphatic drainage due to tumors or fibrosis
Obstructive sleep apnea

Question 5

Signs and symptoms of pulmonary edema

Answer 5

Cough, orthopnea, rales
Hemoptysis, sputum frothy due to air mixed with secretions, blood-tinged
Breathing labored as it becomes difficult to expand lungs, feeling as if drowning
Hypoxemia
Cyanosis

Question 6

Treatment for pulmonary edema

Answer 6

Treatment for causative factors
Supportive care such as oxygen
Positive pressure mechanical ventilation may be necessary
Increased risk of pneumonia

Question 7

Pulmonary Embolis

Answer 7

Blood clot of mass of other material that obstructs the pulmonary artery or branch of it, blocking blood flow through the tissue.
most are thrombi or blood blots originating in deep leg veins - most common cause of death in hospitals
Emboli usually cause respiratory impairment because fluid and blood fill the alveoli in the involved area
Large emboli - affect cardiovascular system causing right-sided heart failure and decreased cardiac output (shock).
Death is usually due to embolus plus reflex vasoconstriction due to released chemical mediators like serotonin and histamine.
90% originate in deep veins, primarily in legs
Fat emboli - bone marrow resulting from fracture of a large bone
Endocarditis
Amniotic fluid emboli from placental tears during labor and delivery
Tumor cell emboli
Air embolus injected into a vein

Question 8

Cor pulmonale

Answer 8

Abnormal enlargement of the right side of the heart as a result of disease of the lungs or the pulmonary blood vessels

Question 9

Phlebothrombosis

Answer 9

Phlebothrombosis occurs when a blood clot (thrombosis) in a vein (phlebo) forms independently from the presence of inflammation of the vein (phlebitis).

Question 10

Thrombophlebitis

Answer 10

Thrombophlebitis is phlebitis (vein inflammation) related to a thrombus (blood clot).

Question 11

Risk factors for pulmonary emboli

Answer 11

Immobility 
Trauma
Surgery to legs
Childbirth
Congestive heart failure
Dehydration
Increased coagulability of the blood
Cancer
Thrombi can break off with sudden muscle action or massage, trauma or changes in blood flow.

Question 12

Signs and symptoms of emboli

Answer 12

Transient chest pain
Cough
Dyspnea
Larger emboli - chest pain increases with coughing or deep breathing, tachypnea, dyspnea develop suddenly
Hemoptysis
Fever
Hypoxia - stimulates sympathetic response with anxiety and restlessness, pallor, tachycardia
Massive emboli - severe crushing chest pain, low blood pressure, rapid weak pulse, loss of consciousness
Fat emboli have specific symptoms - acute respiratory distress, petechial rash on trunk (bleeding under skin), neurologic signs like confusion and disorientation

Question 13

Treatment for emboli

Answer 13

Assessment of risk factors
Preventative measures
Compression stockings
Filter in the inferior vena cava
Oxygen
Heparin - anticoagulant
Streptokinase - fibrinolytic agents
Embolectomy

Question 14

Atelectasis

Answer 14

Nonaeration or collapse of a lung, or part, hypoxia
Could be from obstruction or compression
Increased respiratory rate can temporarily control CO2 levels
If not reinflated, tissue can become necrotic and infected
Obstructive or resorption - when total obstruction due to mucus or tumor
Compression - mass such as a tumor exerts pressure on a part of the lung and prevents air from entering
Pressure in pleural cavity is increased (fluid or air) and the adhesion between the membranes is destroyed the lung cannot expand
Increased surface tension in alveoli - pulmonary edema or respiratory distress syndrome
Fibrotic tissue in lungs or pleura may restrict expansion
Postoperative - particularly after abdominal surgery, restricted ventilation due to pain or abdominal distension, shallow respirations from medications, increased secretions with decreased cough effort

Question 15

Signs and symptoms of atelectasis

Answer 15

Large areas cause dyspnea, increase heart and respiratory rate, chest pain, chest expansion may appear abnormal

Question 16

Pleural Effusion

Answer 16

Presence of excessive fluid in the pleural cavity, more often only one lung
Pleurisy may precede or follow
Large amounts of fluid increase pressure in the cavity and then cause separation of the membranes preventing cohesion during inspiration, prevent expansion of the lung, leads to atelectasis.
Different types of fluid can collect: exudative - response to inflammation from for example a tumor which allows increased capillary permeability and protein and white blood cells to leak into the cavity
Transudates - watery effusions (hydrothorax) that result from increased hydrostatic pressure or decreased osmotic pressure in blood vessels, leading to a shift of fluid out of the blood vessels into the potential space in the pleural cavity.
Hemothorax - when fluid is blood from trauma, cancer or surgery.
Empyema - when fluid is purulent as a result of infection - related to pneumonia

Question 17

Signs and symptoms of pleural effusion

Answer 17

Dyspnea
Chest pain
Increased respiratory and heart rates
Dullness to percussion and absence of breath sounds over affected area
Tracheal deviation and hypotension indicate massive effusion

Question 18

Thoracocentesis

Answer 18

Needle aspiration to remove fluid and pressure

Question 19

Pneumothorax

Answer 19

Air in the pleural cavity

Air at atmospheric pressure and separation of membranes by air prevent expansion of lung, leads to atelectasis.

Question 20

Closed pneumothorax

Answer 20

Occurs when air can enter the pleural cavity through an opening directly from the internal airways - no opening in chest wall

Question 21

Simple or spontaneous pneumothorax

Answer 21

Tear on the surface of the lung allows air to escape into pleural cavity, as lung tissue collapses it seals off the leak

Question 22

Secondary pneumothorax

Answer 22

Underlying respiratory disease resulting from rupture of emphysematous bleb on surface of lung or erosion by a tumor through visceral pleura.

Question 23

Open pneumothorax

Answer 23

Atmospheric air entering the pleural cavity through opening in chest wall - trauma or surgery

Question 24

Sucking wound

Answer 24

Large opening in chest wall, sound of air moving in and out makes sucking sound.

Question 25

Tension pneumothorax

Answer 25

Most serious
Opening through chest wall and parietal pleura (open pneumothorax) or from a tear in the lung tissue and visceral pleura (closed pneumothorax) that causes atelectasis.
Damage creates a flap of tissue or one-way valve where on expiration the valve is sealed off, preventing removal of air from pleural cavity, compressing other lung and inferior vena cava
Severe hypoxia and respiratory distress

Question 26

Signs and symptoms of pneumothorax

Answer 26

Atelectasis
Dyspnea
Cough
Chest pain
Unequal expansion
Hypoxia - sympathetic response - anxiety, tachycardia, pallor.
Interference with venous return - hypotension.

Question 27

Flail chest

Answer 27

Fractures of the thorax
Contusion with edema, bleeding in lung tissue
Chest wall rigidity is lost resulting in paradoxical movement during inspiration and expiration
Inspiration - usual decrease in pressure inside the lungs then the flail or broken section moves inward instead of outward as pressure is decreased, preventing expansion of the affected lung.
Flail section can compress adjacent lung tissue, pushing air out and up the bronchus, “stale” air can cross from damaged lung to other lung
On expiration - unstable flail section is pushed outward by increasing intrathoracic pressure, paradoxical movement of ribs alters airflow, air from unaffected lung moves across into the affected lung as outward movement of ribs decreases pressure in the affected lung
Hypoxia results from limited expansion and decreased inspiratory volume, shunting and decreased venous return.

Question 28

Infant Respiratory Distress Syndrome

Answer 28

Common cause of neonatal deaths, especially in premature.
Surfactant - reduces surface tension, first produced between 28 and 36 weeks gestation. In utero stress can hasten maturation.
Without adequate surfactant, each inspiration is very difficult because the lungs totally collapse during each expiration, poorly developed alveoli are difficult to inflate, inadequate blood and oxygen supply further deters production of surfactant.
Atelectasis results
Poor lung perfusion, lack of surfactant lead to increased alveolar capillary permeability with fluid and protein (fibrin) leaking into the interstitial area. Further impairs lung expansion, decreases lung diffusion.
Can cause brain damage due to hypoxia.
Acidosis
Strenuous muscle activity needed to breathe requires more oxygen than what is available, anaerobic metabolism and increased lactic acid.
Acidosis causes pulmonary vasoconstriction and impairs cell metabolism, reducing synthesis and secretion of surfactant.

Question 29

Signs of respiratory distress in infant

Answer 29

Respiratory rate of 60 bpm or more
Nasal flaring
Subcostal and intercostal retractions
Rales
Low body temp
Frothy sputum
Expiratory grunt
Blood pressure falls
Cyanosis and peripheral edema
Severe - decrease breath sounds, responsiveness, apnea

Question 30

Adult or Acute Respiratory Distress Syndrome

Answer 30

Shock lung, wet lung, stiff lung, postperfusion lung
Restrictive lung disorder
Systemic sepsis, prolonged shock, burns, aspiration, smoke inhalation
Onset usually 1 to 2 days after an injury - associated with multiple organ dysfunction
Increased permeability of alveolar capillary membranes, increased fluid and protein in interstitial area and alveoli, damage to surfactant producing cells.
Decreased diffusion of oxygen, reduced blood flow, difficulty expanding lungs, atelectasis.
Reductions in tidal volume and vital capacity.
Damage progresses as increased numbers of neutrophils migrate to lungs, release proteases and other mediators
Hyaline membranes form from protein-rich fluid in alveoli, platelet aggregation and microthrombi develop in pulmonary circulation, stiffness and decreased compliance
Necrosis and fibrosis, pneumonia, congestive heart failure.

Question 31

Causes of Acute Respiratory Distress Syndrome

Answer 31

Ischemic damage to lung tissue, inflammation from toxic chemicals or smoke, excessive oxygen concenetration in inspired air, severe viral infections in lungs, toxins from systemic infection, fat emboli, aspiration of highly acidic gastric contents, lung trauma.

Question 32

Signs and Symptoms of Acute Respiratory Distress Syndrome

Answer 32

Dyspnea, restlessness, rapid, shallow respirations, increased heart rate
Decrease in oxygen concentration in blood
Rales
Accessory muscles
Productive cough
Cyanosis
Lethargy with confusion
Respiratory acidosis
Metabolic acidosis

Question 33

Acute respiratory failure

Answer 33

End result of many pulmonary disorders
Pao2 less than 50mmHg or PaCo2 greater than 50 mmHg
Emphysema
Acute respiratory disorders (flail chest, tension pneumothorax), pulmonary embolus, acute asthma.
Can be brought on by pneumonia, pneumothorax, central nervous system depression
Myasthenia gravis, amyotrophic lateral sclerosis and muscular dystrophy cause ARF
Rapid shallow breathing, laboured, hypoxia, hypercapnia, tachycardia, lethargy, confusion.

Question 34

Perfusion

Answer 34

Movement of blood into and out of the capillary beds of the lungs to body organs and tissues

Question 35

Briefly explain how carbon dioxide plays a major role in maintaining the pH of blood.

Answer 35

The majority of the carbon dioxide produced as a waste product of cell metabolism diffuses into the red blood cells (RBCs), where it is briefly converted to carbonic acid and then immediately converted to bicarbonate ions. These ions can diffuse back into the blood plasma, acting as a buffer.

Question 36

Cyanosis

Answer 36

Increasing concentration of of unoxygenated hemoglobin