Respiratory Flashcards
Acute asthma definition
An asthma exacerbation is an acute or subacute episode of progressive worsening of symptoms of asthma, including shortness of breath, wheezing, cough and chest tightness
How common is acute asthma
Roughly 9% of people (5.4million in UK)
160,000 per annum incidence
Who does acute asthma affect
1 in 11 children - in early childhood it is higher in boys than girls -> in adulthood this is the other way round
160,000 per annum incidence
1 in 12 adults
What causes acute asthma
Airway inflammation and hyper responsiveness - different underlying disease processes and variations in severity, clinical course and response to treatment
• Airway limitation is usually reversible, either spontaneously or with treatment
- Chronic asthma – may be irreversible as a result of wall remodelling and mucus impactation
Characterised into:
Extrinsic: allergens can be identified by +ve skin-prick reactions to common inhaled allergens, e.g. dust mite, pollen and fungi, in adults sensitisation to chemicals or biological products in the workplace may be the cause
Intrinsic: often starts in the middle age and no definite external cause can be identified, many pts do show a degree of atopy and on close questioning give a hx of respiratory symptoms consistent with childhood asthma
Risk factors for asthma
- Personal or Fx of atopic disease – asthma, eczema, allergic rhinitis or allergic conjunctivitis
- Respiratory infections in infancy
- Exposure to tobacco smoke and inhaled particulates
- Obesity
- Social deprivation
- Flour dust and isocyanates from paint
Symptoms/signs of asthma
- Variable symptoms
- Wheeze, cough, breathlessness and chest tightness
- Symptoms are commonly diurnal (worse at night or early morning) and/or triggered or exacerbated by exacerbated by exercise, viral infection and exposure to cold air or allergens
- In children, it can also be triggered by emotion and laughter
- In adults, it can be triggered by use of NSAIDs and B-blockers
Signs - wheeze in auscultation
DDx for asthma
- Normal structures
- Skin infections
- Benign tumours
- Malignant primary tumours
- Thyroid lumps
- Salivary gland lumps
- Congenital and developmental lumps carotid body tumours
- Aneurysms
- Trauma
Investigations for asthma
1st LINE: - PEAK FLOW MEASUREMENT - O2 SATS – performed immediately - SHORT-ACTING BRONCHODILATOR TRIAL – should be initiated immediately, lack of response is unsual and suggests that the condition is not caused by asthma • CONSIDER: ABG and CXR
Management for asthma
• ACUTE:
- MILD EXACERBATION: 1ST LINE: inhaled short-acting beta-2-agonist, adjunct: oral corticosteroid
- MODERATE TO SEVERE EXACERBATION: 1ST LINE: oxygen and inhaled short-acting beta-2-agonist, + oral corticosterioid,
• SYMPTOM MANAGEMENT:
- OCCASIONAL SYMPTOMS: PEFR 100% predicted. Inhaled short acting β2 agonist as required
- DAILY SYMPTOMS: PEFR≤80% predicted. Add regular inhaled low dose corticosteroids up to 800µg daily
- SEVERE SYMPTOMS: PEFR 50-80% predicted. Add inhaled LABA (Long acting β agonist), if still not controlled add either LTRA (Leukotriene receptor antagonist) or oral theophylline
- SEVERE SYMPTOMS: PEFR 50-80% predicted. Increase inhaled corticosteroids up to 2000µg daily
- SEVERE SYMPTOMS DETERIORATING: PEFR≤50% predicted. Add 40mg prednisolone daily
Prognosis and complications of asthma
Prognosis is dependant on cause
Drug complications e.g. salbutamol induced tremor
Bronchial Carcinoma definition
Cancer that begins in the tissue that lines or covers the airways of the lungs, including small cell and non- cell lung cancer
How common is bronchial carcinoma
Accounts for 9% of primary lung tumours
Most common malignant tumour in the western world
Third common cause of death after heart disease and pneumonia
Who does bronchial carcinoma affect
3:1 M:F
What causes bronchial carcinoma
• Non-small cell: exposure to radon, second-hand smoke, pollution etc
- Squamous (40%): most present as obstructive lesion leading to infection, occasionally cavitates, local spread common, widespread mets occur late
- Large Cell (25%): poorly differentiated tumour, mets easily
- Adenocarcinoma: most common lung cancer associated with asbestos exposure, proportionally more common in non-smokers, usually occurs peripherally, local and distant mets
• Small-cell (20-30%): arises from endocrine clls (Kulchitsky cells), secretes polypeptide hromones, early development of widespread mets, responds to chemo, poor prognosis
Risk factors for bronchial carcinoma
Smoking Urban areas Passive smoking Exposure to asbestos Possibly also contact with arsenic, chromium, iron oxides and the products of coal combustion
Symptoms of bronchial carcinoma
- Local effects of tumour within a bronchus: cough, chest pain, haemoptysis and breathlessness
- Spread within the chest: may directly involve the pleura and ribs, causing pain and bone fractures, spread to incolve the brachial plexus and causes pain in the shoulder and inner arm (Pancoast tumour), spread to the sympathetic ganglion (horner’s syndrome) and spread to the LRL nerve causes hoarseness and bovine cough, tumour may directly involve the oesophagus, heart or SVC
- Metastatic disease: mets are common to bone (presenting with pain and sometimes spinal cord compression) and brain (change in personality, epilepsy, focal neurological signs
- Non-metastatic manifestations: rare apart from finger clubbing, amy also be malaise, lethargy and weight loss
Signs of bronchial carcinoma
• Often no physical signs, although lymphadenopathy signs of a pleural effusion, lobar collapse or unresolved pneumonia may be present
Investigations for bronchial carcinoma
- Confirm the diagnosis: CXR will usually be abnormal by the time a lung cancer is causing symptoms, round shadow, the edge of which is fluffy or spikey, may be evidence of cavitation, lobar collapse, a pleural effusion or secondary pneumonia, spread through the lymphatic channels give rise to lymphangitis carinomatosis, apprearing as streaky shadowing throughout the lung, a minority of tumours may be hidden by the mediastinum, so possibly order a CT after normal CXR for a smoker with haemoptysis
- Determine the histology: sputum is examined for malignant cells, bronchoscopy is used to obtain biopsies for histological investigations and washings for cytology, transthoracic fNA under radiographic guidance is useful for obtaining tissue diagnosis from peripheral lesions
- Assess the spread of the tumour: PET CT
Management of bronchial carcinoma
- Non-small-cell lung cancer: surgery can be curative in non-small-cell cancer, neo-adjuvant chemo may downstage tumours to render them operable, adjuvant post-operative chemotherapy and radiotherapy improves survival, radiotherapy in high doses can produce good results in patients with localised squamous carcinoma if surgey is declined, complications are radiation pneumonitis and fibrosis, palliative radiotherapy is useful for bone pain, haemoptysis and SVC obstruction, chemotherapy is given in advanced disease and improves median survival from 6 to 10 months
- Small cell lung cancer: limited disease (confined to a single anatomical or radiation field) is treated with combined chemo and radiotherapy with 25% survival at 5 years extensive disease is reated with chemo with a median survival of 9-13 months and a 2-year of 20%
Prognosis and complications of bronchial carcinoma
Dependant on cancer and staging
Pneumothorax definition
When air gains access to and accumulates in the pleural space
How common is a pneumothorax
24/100,00 a year for men and 10/10,000 for women
Tends to affect young people as they tend to be fitter.
Causes of a pneumothorax
- PRIMARY: primary spontaneous pneumothorax occurs without preceding trauma or precipitating event, and develops in a person without clinically apparent pulmonary disease
- SECONDARY: secondary spontaneous pneumothorax occurs as a complication of an underlying pulmonary disease, with COPD from cigarette smoking being the most common predisposing condition in the US and accounts for approx. 70% of these pneumothoraces, other predisiposing respiratory conditions include pneumocystitis jirovecuu respiratory infection, CF and TB
Risk factors for pneumothorax
Cigarette smoking Family history of pneumothorax Tall and slender body build Age <40yrs Recent invasive medical procedure Chest trauma Acute severe asthma COPD TB AIDS- related pneumocystitis CF
Symptoms/ signs of pneumothorax
Presence of risk factors
Chest pain - occurs on the same side as the pneumothorax
Dyspnoea - degree depends on the size of the pneumothorax and presence and severity of pre existing lung disease
Hyper expanded ipsilateral hemithorax- degree depends on the size of the pneumothorax and whether a tension pneumothorax develops
Hyper- resonance on percussion of the affected side
Ipsilateral absent or finished breath sounds
DDx of pneumothorax
Asthma, acute exacerbation COPD, acute exacerbation PE MI Pleural effusion Bronchopleural fistula Fibrosing lung disease Oesophageal perforation Giant Bullae
Investigations of pneumothorax
- CXR – visceral pleural line typically identified, if the patient has an underlying lung disease, other abnormalities such as emphysema, lung masses and pulmonary infiltrates may be present
- CONSIDER – CT chest, chest ultrasound, bronchoscopy
Management of pneumothorax
• TENSION PNEUMOTHORAX: 1ST LINE: immediate needle decompression + oxygen therapy + tube thoracostomy
• ACUTE:
- PRIMARY SPONTAENOUS PNEUMOTHORAX: 1ST LINE – WHEN SMALL: supplemental oxygen therapy and observation, WHEN BREATHLESS OR LARGE –supplemental oxygen therapy and percutaneous aspiration
o When aspiration fails, a chest tube or small bore cathter should be inserted
- SECONDARY SPONTANEOUS PNEUMOTHORAX/PATIENT IS >50: 1ST LINE – WHEN SMALL: hospitalisation and supplemental oxygen, WHEN MODERATE: hospitalisation and supplemental oxygen + percutaneous aspiration, WHEN LARGE: hospitalisation and supplemental oxygen + chest-tube thoracostomy
• TRAUMATIC PNEUMOTHORAX: hospitalisation and supplemental oxygen + percutaneous aspiration
• All patients not to fly for two weeks after treatment.
Prognosis and complications of pneumothorax
Prognosis - primary and secondary = at risk for recurrent pneumothoraces
Complications- re-expansion pulmonary oedema
- talc pleurodesis-related ARDS
Pleural effusion definition
- A pleural effusion results when fluid collects between the parietal and visceral pleural surfaces of the thorax
- A thin layer of fluid is always present in this space for lubrication and ease of movement of the lung during inspiration and expiration
- If the normal flow of fluid is disrupted with either too much fluid produced or not enough removed then fluid accumulates resulting in a pleural effusion
How common is a pleural effusion
Affects 1.5 million people in the US
Causes of pleural effusion
• Leading cause is CHF and pneumonia is second
• Excessive accumulation of fluid in the pleural space. Can be detected clinically when more than 500mL, but on X-ray more than 300mL. Massive effusions are most commonly malignant in origin.
• Pleural effusions are transudates or exudates. Transudates occur when the balance of hydrostatic forces in the chest favour the accumulation of pleural fluid; occasionally they occur due to movement of fluid from the peritoneum or retroperitoneal space. Differentiation of transudate from exudate is the key to subsequent management; treatment for a transudative effusion is that of the underlying disease while treatment of an exudate often requires specific pleural intervention.
• Transudate: Pleural fluid protein <30g/L. Heart failure. Hypoalbuminemia (e.g. nephrotic syndrome, cirrhosis). Constrictive pericarditis. Hypothyroidism. Ovarian fibroma producing right sided effusion (Meigs’ syndrome).
• Exudate: Pleural fluid protein >30g/L. Infection (empyema/Parapneumonic effusion/TB). Malignancy (primary or secondary). PE with infarction. Connective tissue disease. Rare causes: (post MI syndrome, acute pancreatitis, mesothelioma, sarcoidosis, chylothorax, drugs e.g. methotrexate, amiodarone).
• USE LIGHT CRITERIA – IF ONE OF THE LIGHT CRITERIA IS PRESENT IT IS EXUDATE:
- Effusion protein/serum protein ratio greater than 0.5
- Effusion lactate dehydrogenase (LDH)/serum LDH ratio greater than 0.6
- Effusion LDH level greater than two-thirds the upper limit of the labs reference range of serum LDH
Risk factors for pleural effusion
CHF- most common cause of pleural effusion
Pneumonia
Malignancy
Recent coronary artery bypass graft surgery
PE
MI
RA
Symptoms and signs of pleural effusion
Presence of risk factors
Pleuritic chest pain- commonly presents with pain that is worse with inspiration and may be exacerbated by cough and movement
Cough - productive cough may be present if effusion results from pneumonia, however fluid collection and irritation of the pleural surfaces alone causes a non- productive cough
Quieter breath sounds - over the area of effusion
Decreased or absent tactile fremitus
Dyspnoea
Stony dullness to percussion
DDx of pleural effusion
Pleural thickening
Pulmonary collapse and consolidation
Elevated hemidiaphragm
Pleural tumours / extrapleural fat
Investigations for pleural effusion
• 1st LINE:
- PA and lateral CXR - dense homogenous shadow occupying part of the hemithorax and a meniscus visible on an erect CXR
- Pleural ultrasound – more sensitive and specific than CXR
- LDH and protein in pleural fluid and serum – indicates an exudate if the ratio of pleural fluid protein to serum protein is >0.5 – absence of these findings the effusion is likely to be a transudate
- RBC count in pleural fluid
- WBC count and differential of pleural fluid
- Cytology of pleural fluid – cytology is positive is >60% of malignant pleural effusions – abnormal cells present in malignant pleural effusion
- pH of pleural fluid – needs to be measured with an ABG machine
- Glucose in pleural fluid – almost 100% of effusions due ot empyema and rheumatoid arthtirits
- FBC and CRP – infection such as pneumonia
Management of pleural effusion
- CHF – 1ST LINE: diuretic e.g. furosemide, if large include a therapeutic thoracentesis
- INFECTIVE – 1ST LINE: empirical IV abx e.g. amoxicillin/clavulanate or vancomycin
