Pulmonary Disorders

Obstructive Disorders

Airways obstruction increases airflow resistance and the work of breathing (WOB) as indicated by decreased peak flow rates. Causes are:

·         Reversible factors

·         Inflammation

·         Bronchospasm

·         Mucus plugging

·         Irreversible factors

·         Fibrotic airway walls

·         Floppy airways as a result of the loss of elastic recoil

·         Localised lesions e.g. upper airway tumour or foreign body

Chronic Obstructive Pulmonary Disease (COPD)

COPD is an umbrella term for chronic bronchitis and emphysema. It is the fifth greatest cause of disability worldwide (WHO, 1996). It is a solely progressive disease and most airways obstruction is fixed, although some reversibility may be demonstrated with medication (O’Driscoll, 1997). Occasionally asthma is included in the umbrella; however it is usually classified separately. Diagnostically, FEV₁ can be used to differentiate between asthma and COPD:

·         FEV₁ > 60% = mild COPD

·         Aerobic programme suitable

·         FEV₁ 40 - 60% = moderate COPD

·         Peripheral muscle training required

·         FEV₁ < 40% = severe COPD

·         Isolated muscle groups and ROM

·         Above 55% indicate that decreased oxygen is unlikely during exercise

The table below identifies some of the distinguishing features between asthma and COPD:

	Asthma	COPD
Smoking History	Not necessarily	Yes
May start in childhood	Yes	No
Onset	Variable	Slow
Timing of symptoms	Episodic, seasonal	Minor variations only
Provocation of symptoms	Weak stimulus e.g. cold air	Strong stimulus e.g. infection
Cough at night	Patient wakes coughing	Patient wakes then coughs
Sputum	Contains eosinophils	Contains neutrophils
Bronchodilator response	Yes	Sometimes
Steroid response	Yes	Sometimes

Causes include:

·         Smoking

·         Poverty

·         Male > female

·         Occupational hazards

·         Housing

·         Air pollution

·         Childhood respiratory illness

·         In utero exposure to smoking or malnourishment

Symptoms include:

·         Respiratory

·         Cough

·         Sputum

·         Dyspnoea (shortness of breath)

·         Wheeze

·         Non-respiratory

·         Fatigue

·         Muscle weakness

·         Weight loss

Clinical features include:

·         Laboured breathing

·         Plethoric (excessive blood) or cyanotic appearances

·         Weight loss

·         Barrel chest (rounded, bulging chest)

·         Pursed lip breathing

·         Prolonged expiration

Chronic bronchitis is an inflammation of the bronchi with an expectorating cough for at least 3 months a year for 2 years. Repeated inhalation of tobacco smoke irritates the lining leading to inflammation, mucus hypersecretion and occasionally bronchospasm. Inflammation of distal airways progresses to the proximal airways, both causing breathlessness. If acute it can resolve, however if chronic it may lead to fibrotic changes including scarring.

Emphysema is a long-term, progressive disease of the alveoli and bronchioles with secondary effects on larger airways. It is usually caused by alveolar damage from smoking that prevents their ability to hold their shape on exhalation. Centrilobular emphysema affects the bronchioles, panlobular emphysema affects the alveoli.

The airways obstruction of emphysema leads to hyperinflation and reduced expiratory flow, causing expired air to not be fully expelled before the next inspiration, leaving air trapped in the distal airways and a positive pressure in the chest (intrinsic PEEP). This is predominant in exacerbations or rapid breathing. Hyperinflation can be caused by two mechanisms:

·         Passive Hyperinflation

·         Caused by reduced elastic recoil

·         Allows the airways to collapse on expiration and leads to gas trapping

·         Dynamic Hyperinflation

·         Caused by the patient having to actively sustain inspiratory muscle contraction in order to hold open the airways (McCarren, 1992).

·         This is achieved at the cost of WOB, a barrel chest, reduced diaphragmatic contribution to breathing and a lung volume that can exceed the predicted TLC (Decramer, 1997)

Chronic bronchitis is gradual, patchy airway narrowing and emphysema is floppy, obstructed airways. Together, as in COPD, this results in uneven distribution of ventilation. Damaged alveoli hinder gas exchange which leads to the development of anaerobic metabolism.

Asthma

Asthma is a chronic inflammatory condition of the airways, characterise by a widespread airflow obstruction that can be reversible spontaneously or with treatment.

Symptoms:  Wheeze (Bronchial restriction), breathlessness and cough (can be closely related to COPD), gastro-oesophalangeal reflex-found in 82% asthmatics (worsen after meals, lying down, after exercising)

Causes: Smoking during pregnancy, family history, post viral infection, allergies (food, dust), exercise without warm up, weather-changes in temperature, stress- central nervous system interaction, chest infection- especially infants, pollen.

Diagnosis:  Peak Flow (respiratory function test) x 3 = best result and HPC

                    PF > 60% SEVERE AIRWAY OBSTRUCTION

Severe acute Asthma

• ·         History of several weeks of wheezing
• ·         PF< 50 %
• ·         No response to bronchodilator
• ·         Fatigue will result to decreased respiratory effort and PAC02
• ·         Hypotension- pulmonary capillaries compressed by overinflated chest

Mild chronic Asthma

• ·         Dry cough
• ·         Morning wheeze
• ·         PF varies by less than 25%

Severe Chronic Asthma

• ·         Frequent exacerbations
• ·         Symptoms effect quality of life
• ·         PF- varies by more than 25%
• ·         Use of anti-inflammatory dugs

Types:

1)      Intrinsic

·         Not related to allergies

·         Airways are hyper-reactive- to stimuli that are usually harmless 

·         Mucus production and bronco-constriction

·         Develops in adulthood

2)      Extrinsic

·         Over activity of the immune system to allergens

·         Also presents with bronco spasms and mucus product

·         Develops in early life

3)       Exercise induced Asthma

·         During or while exercising present

·         Extreme SOB

·         Present in 80% Asthmatics

Physiology

1)      The sensitization stage- exposed to allergens will stimulate immunoglobin-E antibodies in the serum. IgE will become fixed to mast cells and together will attack the allergens by realising bronco-costriction mediators or histamine.(Inflammation begins)

2)      Hyper active stage- continued exposure to allergens or stimuli leads to mast cells degranulation  and release of inflammatory cytokines ex. eosinophils (white blood cells)– chronic inflammation damages the  epithelia layer causing bronchial hyper-activity

3)      Hyper-active airways develop bronco spasm  as soon as  there is a response to stimuli which will increase work of breathing

4)      Long lasting structural changes may stiffen the airway walls which will contribute to further narrowing of the airways

Treatment

1)      Drugs

·         Short acting bronchodilators

·         Inhaled cortico-steroids

·         Long acting bronchodilators

2)      Physiotherapy

·         Breathing  control exercises: ACOB - used to aid relaxation

·          Exercises to maintain cardiovascular fitness- aerobic training

Study by Emtner (1996) found that aerobic training

o   Will decrease exercise-induced asthma

o   Increase conditioning

o   Increase confidence – independence

o   Decrease number of asthma attacks

Cystic Fibrosis

Cystic Fibrosis (CF) is a chronic, progressive obstructive disorder affecting the exocrine glands (secretes hormones directly to the target organ). It is an autosomal, recessive disorder that defects chromosome 7. Diagnosis is suspected if infants show failure to thrive, meconium ileus (obstructive bowel from the kid’s first shit) or repeated chest infections. Confirmation is by a test for abnormally salty sweat at age 6 weeks. The CF gene is active in epithelial cells and impairs ion and water transport across epithelial surfaces of the body, causing dehydration of secretions and obstruction of various body lumens.

In the lungs, sodium and chloride ions cannot escape from the epithelial cells into the airways in order to maintain hydration of mucus, which becomes thick and sticky. This encourages bacterial adherence, promoting chest infections and dying neutrophils release DNA, whose strands bind together and thicken secretions further. This demonstrates the importance of regular and effective hand washing from the MDT.

Pneumothorax occurs in 10% of children and 20% of adults due to a rupture of a subpleural bleb or bulla (Noppen et al, 1994).Resting energy expenditure is 20% higher than in normal adults, half of it caused by the inefficiency of breathing with hyperinflated lungs

Clinical features include:

·         Incessant coughing

·         Small stature

·         Reduced energy supply for malabsorption and anorexia

·         Energy demand increased by up to 25% (Shepherd, 1988) due to increased WOB

·         Delayed puberty

·         Flatus

·         Increasing breathlessness

·         Unrelenting weariness

Exacerbation is indicated by weight loss or worsening respiratory symptoms. Secretions become thicker and possibly less productive.

In the later stages, FEV ₁ declines, partial arterial pressure of oxygen falls and eventually the partial arterial pressure of carbon dioxide increases.

Treatment includes:

·         Education

·         No smoking in the home

·         CF does not have cognitive impairments

·         Normal physical activities, within their limitations, are advised

·         CF is not infectious

·         Medication

·         Antibiotics for infections

·         rhDNase contains a clone of the gene responsible for breaking down DNA, and when given as a sputum viscosity, improve FEv_1, reduce exacerbations by 30% and lessen intractable atelectasis

·         Benefits 50% of patients and nearly doubles their cost of care

·         Nutrition to prevent malnutrition

·         Surgery

·         Multiple pneumothoraces lead to thoracoscopic pleurodesis

Physiotherapy intervention includes:

·         Minimise the cycle of exercise secretions and airway damage

·         If convenient for all, physiotherapy should be co-ordinated with nebuliser treatment

·         Hypertonic saline clears more secretions than isotonic saline (Riedler, 1996)

·         ACBT

·         PEP mask and flutter

·         Encourage independence

·         Exercise – especially swimming

·         Reduce breathlessness

·         Improve lung function (Dodd, 1991)

·         Increased exercise tolerance and mucociliary clearance (Bye et al, 1997)

·         Pulse rate of 50-75% of their maximum exercise capacity

·         Minimum 30 minutes, 4 times a week

·         If fatigue is common, little and often approach

·         Patients with advanced disease are less likely to benefit, partly because of fatigue and partly because little extra tidal volume can be added to  hyperinflated lungs

·         Postural drainage

·         15 mins in younger children, longer in adults or people with excessive secretions

·         Use of percussion and vibs

Patients require 3-monthly physiotherapy reviews (RCP, 1996). Outcomes arebased on quality of life measures such as exercise tolerance, questionnaires and well-being scales (Orenstein and Kaplan, 1991).

Precautions:

·         Patients should not be asked to cough unnecessarily as it cause collapse of central airways with impairment of sputum clearance (Zapletal et al, 1983)

·         High pressures are not necessary in NIV and should be avoided for risk of pneumothorax

·         Blood streaking of sputum is common and should be disregarded, but haemoptysis (coughing up blood) should be noted and physiotherapy halted. This is a contraindication to exercise.

·         Risk of osteoporosis in later stage disease

·         When exercising, avoid desaturating by more than 5% or an absolute level below 80% (Dodd, 1991), using interval training, reduced workload or added oxygen

·         In advanced disease, added oxygen allows longer periods of exercise and may postpone the development of pulmonary hypertensions (Marcus, 1992)

Bronchiectasis

Chronic irreversible dilation of Bronchi.

Diagnosis: X-RAY and CT scan

Bronchiectasis is usually poor diagnosed due to its common path way with related diseases such as: severe respiratory infection, foreign body inhalation, cystic fibrosis, tuberculosis, inhaled smoke

Cause: post infection, Immune defects, gastric aspiration, localised bronchial obstruction

Pathophysiology

• Chronic inflammation damages the elastic and muscular components of the airways
• Excess mucus –infection- inflammation- further obstruction- vigorous circle
• Mucus will sit on cilia cells making further  damage
• Continued inflammation may result to bronco spasms and fibrosis
• Advanced disease may lead to pulmonary hyper tension and cor-polmunale 

Clinical features:

• o   Secretions- damaged to cilia insufficient clearance, yellow-green
• o   Hameoptysis: coughing blood - indication of infection
• o   Auscultation: wheeze and crackles
• o   Fatigue, loss of appetite
• o   SOB and couph
• o   Can be misdiagnosed with COPD

Clinical differences between the two:    

  

	Bronchiectasis	COPD
Age	Varied	Older
Smoking	Not necessarily	Usually
Auscultation	Noisy, localised	Diffused crackels
Sputum	Excessive, often thick and green	Moderate
Haemoptysis	Sometimes	No
Finger clubbing	Sometimes	No
X-Ray	Specific	Variable

Medical treatment

Antibiotics to control infection- but do not control inflammation

Steroids - assist in reducing inflammation and reduce sputum

Physiotherapy

o   Education - sputum management

o   Airway clearance techniques: ACOB, positioning, acapella, NIV- may be beneficial with widespread diseases

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Restrictive Disorders

Restrictive disorders are characterised by:

·   Reduced lung volume

·   Poor compliance

·   Increased work of breathing

Restriction is caused by:

·   Shrunken lung tissue e.g. interstitial disease

·   Lung compressed from within the chest wall e.g. pneumothorax

·   Lung compressed by the chest wall e.g. skeletal disorders such as ankylosing spondylitis

·   Reduced ability to expand the lung e.g. neuromuscular disorders such as MS

Pneumothorax

Pneumothorax is air in the pleural space, caused by a rupture in either pleural layer (visceral or parietal). The function of the intrapleural space is to maintain negative intrapleural pressure with pleural fluid to reduce friction for movement during ventilation. The lung shrinks towards the hilum in proportion to the amount of pleural air. This may sometimes cause the mediastinum to shift away from the affected side, especially is the pneumothorax is under tension. Air continues to escape until the pressure is equalised or the collapsed lung seals the hole. Clinical features include:

·   Diminished breath sounds

·   Breathlessness due to a reflex arc (the nerve pathway involved in a reflex action) with afferents carried in the vagus nerve

·   Vagus nerve innervates the visceral pleura

·    Intercostal and phrenic nerves innervates the parietal pleura

·   Pain in 75% of patients

·   X-ray

·   A small pneumothorax can be identified more easily when the film is taken on expiration and the lung is smaller.

Types of pneumothorax include:

·   Spontaneous pneumothorax

·   The apex of the upright lung is subject to greater mechanical stress due to the weight of the lungs pulling down, therefore a spontaneous pneumothorax is more common in the apex

·   It usually occurs in tall, thin young men who are thought to grow faster than their pleura are able to keep up with

·   Secondary pneumothorax

·   This could be due to a:

·   Punctured rib

·   Inaccurate insertion of a cannula

·   High-volume positive pressure ventilation

·   Rupture of an emphysematous bulla

·   Tension pneumothorax

·   When a pleural tear acts as a valve preventing air that enters the pleural space from leaving

·   This is usually in mechanically ventilated patients. Progressive positive pressure displaces the mediastinum and impairs venous return, causing respiratory distress and circulatory collapse.

Treatment

·   When small and asymptomatic, it can be left to heal itself.

·   If a moderate first pneumothorax it can be managed by needle aspiration without hospital admission.

·   A chest drain is used if simpler methods are not adequate or the patient is on a ventilator

·   A larger pneumothorax can be treated with a Heimlich valve, which prevents air re-entering through the chest drain.

·   The ceasing of bubbles from the chest drain indicates that the chest drain can be clamped for some hours and removed if the x-ray shows no reoccurance.

·   Surgical intervention is necessary if these measyures fail r if the condition is recurrent or bilateral.

Physiotherapy Management

·   Education in chest drain management and positioning

·   Lying on good side is often the most comfortable and usually best for V/Q matching, but lying on the affected side may speed the absorption of air (Zidulka et al, 1982)

·   Assisting mobilisation

·   This needs to be gentle is recurrence is likely e.g. immediately after surgery in case the pleura becomes unstuck

Precautions include avoidance of positive pressure techniques (CPAP, IPPB and other non-invasive ventilation strategies, or manual hyperinflation) if there is no functioning chest drain. Patients should be advised to avoid violent or sudden coughing.

Interstitial Lung Disease

Interstitial Lung Disease (ILD) is an umbrella term for ‘diseases that affect the supporting structures of the lung rather than the airspaces’ (Hough, 2001). Over 200 disorders have been identified, usually related to immune disturbance or exposure to toxic agents. Inflammatory changes lead to alveolitis, which may resolve or progress to patchy fibrosis (thickening and scarring of connective tissue), thickened alveolar septa, remodelling of parenchyma (functional tissue of an organ) and shrunken, stiff lungs. Stiff lungs mean fewer functioning alveoli and often excess elastic recoil.

The two main effects are:

·   Increased lung stiffness, which increases the work of breathing

·   Decreased surface area of the alveolar capillary membrane, which impairs gas exchange

Examples include:

·   Fibrosing alveolitis – chronic, progressive form of lung disease characterised by the fibrosis of the interstitium

·   Asbestosis

·   Rhematoid disease

Clinical features emerge after considerable injury due to the lungs large reserve capacity. These include:

·   Shallow breathing to ease elastic load

·   Rapid breathing to sustain ventilation

·   Dry cough (Lalloo, 1998)

·   Fine end-inspiratory crackles caused by popping open of peripheral airways

·   Unchanged by deep breathing or position change

·   Progressive x-ray signs of ‘ground glass’

·   Decreased partial arterial pressure of oxygen because of V/Q mismatch

·   Decreased partial arterial pressure of oxygen because of rapid breathing

·   Hypoxaemia on exercise

·   Dyspnoea that becomes progressively incapacitating

·   Fatigue

·   Digital clubbing in over 50% of patients (Johnston et al, 1997)

Treatment

·   15% of patients respond to steroids (MacNee, 1995)

·   Because fibrosis is often established and irreversible

·   Symptoms are sometimes alleviated by immunosuppressive drugs

·   Breathlessness temporarily relieved by nebulized local anaesthetic

·   Oxygen is needed in the later stages, especially with exercise

·   Lung transplantation offers gope for some patients

·   Physiotherapy to change the breathing pattern is often unhelpful

·   Rapid, shallow breathing reduces the effect of excessive lung recoil

·   Some patients find NIV relieving for WOB

·   In the unlikely event of a patient being mechanically ventilated, manual hyperinflation should be used minimally because the non-compliant lungs are at risk of pneumothorax

Neuromuscular Disorders

Symptoms

• o   Weak inspiratory muscles will restrict expansion
• o   Reduced sputum clearance and reproduction of cough- weak expiratory muscles

Causes: UMN syndrome: multiple sclerosis, muscular dystrophy, Parkinson’s disease

Clinical Features include:

·   Bulbar weakness- aspiration –dysphagia- poor  gag reflex

·   Generalised muscle weakness + respiratory muscle

·   Fatigue and sleep apnoea – reduces quality of life

·   Respiratory muscle weakness may not be detected if limb weakness reduces mobility

·   Inability to cough due to weakness in expiratory muscles- may cause aspiration  and pneumonia

·   NIV - indicated if weakness in respiratory muscles

·   Prolong life and manage symptoms

·   Weaning from NIV may be difficult

·   Oxygen Therapy is not advisable for those that cannot ventilate

·   Use at night if nocturnal hypoventilation causes debilitating symptoms

Physiotherapy:

• ·   Positioning-upright help work of breathing
• ·   Assisted cough
• ·   Monitoring – once VC falls lower than 50%. Since VC below 30% and pac02 rises may lead to ventilator failure
• ·   Inspiratory muscle training

Assessment of respiratory muscles:

Vital Capacity: The volume of gas that can be exhaled after a full inspiration and represent 3 volumes (Inspiratory reserve volume, expiratory reserve volume and tidal volume). It indicates the ability to breathe deeply and cough = inspiratory + expiratory muscle strength. 

VC is sometimes reduced in obstructive disorders and always in restricted disorders

Test: will measure   A) maximum inspiratory pressure + maximum expiratory pressure

                                  B) Both above 80cm H2O Indication good muscle strength

Pleural Effusion

Definition:  Excess fluid in the pleura space

Transudate pleural effusion

 Systemic causes:

·   Left + Right heart failure

·   Cirrhosis

·   Pulmonary embolism

Exudative pleural effusion

·   Infection

·   Malignancy

·   Leukaemia

·   Lymphoma

·   Rheumatoid Arthritis

Types include:

1. Haemothorax:  collection of blood in pleura space due to trauma, malignancy, pulmonary infraction
2. Chylothorax: a milky or chylous pleura effusion due to leakage in the lymph nodes of the thoracic duct into pleura cavity that can be associated with trauma and malignancy

Investigations:

• ·   Ultrasound
• ·   CT  SCAN

Treatment:

• ·   Aspiration
• ·   Chest Drain