Pathology Flashcards
(44 cards)
Asthma
Chronic inflammatory condition due to episodic exacerbations of bronchoconstriction by triggers
Sx - episodic, worse at night, dry cough, wheeze and shortness of breath,
Ix - ECG, peak flow, Blood gasses
Mx - SABA first line when exacerbated sx
- ICS each day to prevent sx
*If failing to resound to treatment in life threatening - BiPAP
**In kids - trial 8-12 weeks of 2 puffs low dose ICS and salbutamol
Acute attack - oxygen given
- Salbutamol and ipratropium bromide by nebuliser
- Hydrocortisone IV
IV Aminophilline if sever attack
Acute asthma diagnosis
- Rapid deterioration in symptoms
- Moderate - PEFR 50-75% predicted
- Severe “ 33-50% predicted, resp rate >25, HR>110, unable to complete sentences
- Life-threatening - PEFR<33%, sats <92%, becoming tired, no wheeze (airways so tight), haemodynamically unstable
Emphysema
Lots of air in the lungs caused by a loss of elastic fibres of alveoli
Cx - Smoking and A1 anti trypsin defect
Sx - SOB
Ix - CT, bloods, lung function tests
Mx - bronchodilators, ICS, antibiotics
- When elastic fibres are removed, leads to increased lung compliance, greater airway space and so greater resistance leading to increased work of breathing, decreasing transfer factor
Pulmonary fibrosis
Replacement of elastic fibres with collagen fibres in alveoli walls leading to stiff walls and reduced lung compliance
Cx - Infections, allergy, toxins, irritants, CT diseases
Sx - shortness of breath, exercise intolerance, dry cough, loss of appetite and weight loss
*Inspiratory reps
Ix - breathing and blood test - restrictive defect with reduced TLCO
CT
Mx - Lifestyle changes
- pirfenidone to slow progression sand reduce collagen growth
Bronchiectasis
- Very large airways, become blocked, inflammation across whole bronchi tube, poor clearance of secretions, (obstructive defect)
- Haemophlious influenza most common
Cx - Infections, cystic fibrosis, cilia not functioning, gamma globulin deficiency
Sx - cough with a lot of sputum, occasional haemoptysis, coarse crepitations, clubbing in fingers
Ix - HRCT 1st choice showing bronchial wall dilation and lack of bronchial wall tapering
- coarse crepitations at base
- Feature of Kartagenrs syndrome
Gamma globulins
IgG - most common, in blood and fluid helping to protect from bacterial and viral infections
IgE - Small amount in blood, increase due to parasites and allergy (Type 1 sensitivity reactions)
IgM - In blood and lymph, first made after infection (Type 2 hypersensitivity reaction)
IgA - Lining respiratory tract, saliva,
IgD - Not fully understood
Pulmonary chondroma
- Benign tumour of cartilage
- More likely to be females
- More likely to be peripheral
- Associated with Carnery’s triad
Pulmonary hamartoma
- Disordered proliferation of mature cartilage, fat and smooth muscle
- More likely males than females
- More likely to be central
- Solitary
TNM grading system
T - Tumour size (1-4)
N - Nodes spread (0-2)
M - Metastases (0-2) - No lungs or liver, just lungs, both
Adenocarcinoma
- Develop more peripherally in the lung
- Associated with areas of fibrous scarring
- Glandular epithelium malignancy
- Most common tumour
Lung cancers
- 3rd most common cancer behind breast and prostate
*80% of cases are smokers
> Non small-cell (80%)
Adenocarcinoma - 40% - non smokers (cavity lesions)
squamous cell carcinoma - 20% - smokers (cavity lesions)
large cell carcinoma - 10%
Mesothelioma - around the lining of an organ
> Small cell (20%)
* cells contain neurosecretory granules that can release neuroendocrine hormones - responsible for multiple paraneoplastic syndromes
Sx - SOB, cough, haemoptysis, finger clubbing, recurrent Pneumonia, weight loss, lymphadenopathy (supraclavicular are often first)
Ix - Chest x-ray, CT
- biopsy of lung tissue
**Raised platelets
Mx - surgery
- radio, chemo or immunotherpy
Mesothelioma
- Tumour of tissue surrounding an organ
- Almost always due to asbestosis exposure
- development of the mesothelioma is usually 20 or more years from the time of exposure
Sx - Chest pain, SOB, weight loss, persistent cough, tiredness
* spread into lung, pleural cavity, hilar lymph nodes usually
Ix - Chest X ray - pleural plaques present (benign)
- thoracoscopy and histology
Mx - surgery
- chemo, radio and immunotherapy
Extra-pulmonary manifestations of lung cancer
> Invasion of local structures
- SVC blocked due to tumour co impression leading to raised JVP
- Recurrent laryngeal nerve compression leading to hoarseness
- Phrenic nerve compression leading to elevation of the hemi diaphragm
- Cushing’s syndrome by ectopic ACTH secretion
- Pancoast tumour at apex of the lung causing Horner’s syndrome
Pancoast tumour
- Growing tumour usually in the apex of the lung that can cause suppression on SVC leading to raised JVP
- Can compress sympathetic plexus resulting in Horner’s syndrome
- Can compress recurrent laryngeal nerve causing a coarse voice
Hypertrophic osteoarthropathy
- Prominent with squamous cell lung cancers
- Clubbing and inflammation of the membrane (periostitis) of joint, especially DIJ
Sx - Swelling of ankles, knees wrists and elbows MC joints and finger clubbing
Transfer/perfusion defect
Transfer/perfusion - Flow of blood to alveolar capillaries (need PaCO2)
Defect - Determines alveolar capillary gas transfer (reduced PaCO2)
Cystic fibrosis
Mutation in Phe508del causing mutation in CFTR gene,C7, leading to a chloride channel defect, affecting mucus secreting cells
Sx - Thick sticky mucus, plugging airways and pancreas, persistent cough, repeated lung infections, wheezing, inflamed nasal passage, failure to thrive, loose greasy stools
*can cause delayed puberty
Ix - newborn blood spot test
Mx - bronchodilators, steroids
- prophylactic antibiotics
Restrictive defect
- Due to stiff alveolar walls, reducing lung compliance (alveolar walls aren’t able to expand)
FEV1 <80% predicted
FVC <80% predicted
FEV1/FVC ratio >70% normal
Obstructive defect
- Airways become narrowed due to inflammation from secretions
FEV1 <80% predicted
FVC = normal or low
FEV1/FVC ratio <70% predicted
Ventilation defect
Ventilation - Flow of air into alveoli
Defect - Reduced flow of air into alveoli due to increase PaCO2 (respiratory acidosis)
Surfactant deficiency
- Type II pneumocytes that secrete surfactant have not yet differentiated to secrete surfactant
- Leads to increased surface tension, reduced lung volume and increased work of breathing
Pneumothorax
- Collapsed lung due to air in pleural cavity pushing on the lung causing it to collapse
Sx - Sudden chest pain and shortness of breath, reduced breath sounds on affected side, hyper resonant on percussion
Cx - injury such as car accident or assault, lung disease such as COPD,
Tension pneumothorax - Air held in pleural cavity under positive pressure causing a mediastinal shift to the opposite side
1st spontaneous - No underlying trauma or conditions (tall people with Marfan’s syndrome for example)
2nd spontaneous - Underlying disease present but no trauma (those with cystic fibrosis)
Iatrogenic - lung biopsy, mechanical ventilation, central line insertion
Ix - CXR - if symptoms obvious no need for scan
Mx - needle aspiration 2nd ICS
- chest drain into triangle ff safety if aspiration doesn’t work
**If secondary pneumothorax and is >2cm and/or SOB, patients should be treated with a chest drain 1st line
Pleural effusions
Blood, lymph or chly in the pleural cavity
Cx - Penetrating injury to lung, heart and great vessels, cancer, infection, heart failure
Sx - reduced expansion, dull percussion, diminished breath sounds at the affected side, sudden shortness of breath, sudden chest pain, tracheal shift to opposite site
Ix - CXR then CT chest
- Protien level>30 =exudative
Mx - Insert chest drain into safe triangle in axilla region - can affect long thoracic nerve and cause winged scapula
‘safe triangle’: Lateral border of pec major, lateral border of latissimus dorsi and horizontal line from the nipple going laterally
Transudative and exudative causes of pleural effusions
Exudative - inflammation, high protein
- lung cancer, pneumonia, rheumatoid arthritis, tuberculosis
Transudative - Fluid shifting, low protein
- congestive cardiac failure, hypoalbuminaemia, hypothyroidism
