Respiratory conditions, signs, causes and differentials Flashcards
Signs of hypercapnia? (8)
- start from head downwards
- coma
- confusion
- drowsiness
- dilated pupils
- bounding pulse
- myoclonus
- hand flap
- tachypnoea
Signs of hypoxia?
Dyspnoea Anxiety Confusion Tachypnoea Cyanosis Bradycardia Tachycardia Sweating
Why does cor pulmonale happen? What is it?
Cor pulmonale AKA pulmonary heart disease, is abnormal enlargement of the right side of the heart.
It occurs because of COPD, which causes vasoconstriction due to low oxygen ventilation of areas of the lung (emphysema), this prevents blood from passing from the right side of the heart THROUGH THE LUNGS, and in to the left side of the heart.
Signs of cor pulmonale?
Right sided heart enlargement
Raised RR - tachypnoea
Raised JVP
Bilateral lower limb oedema
Hepatomegaly
Cor pulmonale is the result of lung disease.
COPD often results in cor pulmonale.
Treatment is oxygen therapy and use of diuretics.
Signs of an severe acute asthma attack?
Severe SOB - can’t complete a full sentence Tachypnoea Tachycardia Silent chest Cyanosis Collapse
General signs of asthma?
Wheeze (polyphonic) Dyspnoea Hyperinflation Chest tightness Tachypnoea
These signs will be:
Diurnal
Prompted by use of aspirin/beta blocker
(If condition is well handled there shouldn’t be any signs)
What are possible differentials for a wheeze?
Asthma COPD Pulmonary disease Cardiac failure Foreign body aspiration Eosinophilic lung disease
Differentials for fine crackles heard by auscultation?
Broncholitis
Pulmonary oedema
Pulmonary fibrosis
Differentials for coarse crackles heard by auscultation?
COPD
Pulmonary oedema
Pulmonary fibrosis
Lung abscess
TB: Tuberculosis lung cavities
Pneumonia (resolving)
Differentials for a pleural rub heard on auscultation?
Consolidation
Pulmonary infarction
Signs of a life-threatening asthma attack?
Cyanosis Poor respiratory effort Silent chest Arrhythmia Hypotension Altered consciousness level Exhaustion - Normal CO2 on ABG (no longer able to hyperventilate)
Possible triggers of acute asthma exacerbation?
Stress
Exercise
Cold air
Allergens: dust mites, pollen, fur
Infection
Smoking/passive smoking
Pollution
NSAIDs
Beta-blockers
What is the definition of asthma?
“Chronic recurrent episodes of dyspnoea, cough, wheeze caused by reversible airways obstruction”
Caused by:
- Bronchial muscle contraction
- Mucosal inflammation
- Increased mucus production
Signs of an acute asthma exacerbation on respiratory examination?
Increased RR
Tracheal tug (possibly) - “abnormal downwards motion of trachea during systole”
Intercostal recession
Signs of pulmonary oedema in a respiratory examination?
Raised JVP
Crepitations/crackles on auscultation
Dullness to percussion
Decreased vocal fremitis
Peripheral oedema: ankles/lower limb and sacrum
Signs of tension pneumothorax in a respiratory examination?
Signs of haemodynamic instability: pulses weak, hypotensive
Tracheal deviation
Hyperresonant to percussion
Absent breath sounds on auscultation
What is the most likely cause of a unilateral silent lung field with a wheeze?
Foreign body aspiration
- totally occludes some airways stopping noise
- partially occludes some airways causing the wheeze
What are the causes of pleural effusion?
Malignancy
Empyema
TB
Pleuritis
Fungal infection
Lupus pleuritis
Chylothorax
Urinothorax
Oesophageal rupture
Haemothorax
Peritoneal dialysis
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is bloody:
What are your differentials?
Malignancy
Asbestosis
Pulmonary infarction
Post cardiac injury syndrome
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is milky white:
What are your differentials?
This is a lipid effusion:
Chylothorax (- lymph from the digestive tract is called chyle, this is caused by disruption of drainage by the thoracic duct)
Cholesterol effusion (- due to TB or rheumatoid pleurisy)
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is black:
What are your differentials?
Aspergillus
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is yellow/green:
What are your differentials?
Rheumatoid pleurisy (uncommon)
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is dark green:
What are your differentials?
Bilothorax (- presence of bile fluid in the pleural space, most often due to biliary surgery or trauma)
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid is like fish paste:
What are your differentials?
Amebic liver abscess (- most common extraintestinal manifestation of entamoeba infection)
Upon sampling a pleural effusion via thoracentesis, you notice that the fluid has pus in it:
What are your differentials?
Empyema
What are the main three organs causing a transudate pleural effusion?
Kidney failure
Liver failure
Heart failure
Which conditions override the hypoxic pulmonary vasoconstriction?
Sepsis
Pneumonia
COPD
Pulmonary fibrosis
What is a shunt?
The pathological process where deoxygenated blood entering the lungs perfuses alveoli that aren’t ventilated.
This results in deoxygenated blood reentering circulation without oxygenation, and reducing the overall oxygen concentration of blood in the body.
Can occur in an area of infection in the lung e.g. pneumonia, or all over in copd
What is wasted ventilation AKA alveolar dead space?
This is when there is an obstruction in the pulmonary capillary or in a larger pulmonary vessel, that prevents blood flow from the pulmonary artery to the pulmonary vein.
This occurs in PE.
Why is a thickening of the alveoli wall a pathological process?
The gap between the pulmonary capillaries and the air of the alveoli is only 1mm thick - very thing.
If this thickened, the diffusion of gases is obstructed!
This causes shunt.
What is respiratory failure?
The lungs produce an inadequate supply of oxygen to the body +/- an inability to clear carbon dioxide from the body
Type 1 = hypoxaemic failure; low oxygen
Caused by lung pathology
Type 2 = ventilatory failure; low oxygen and high co2
Can be compensated (BE >+3) or decompensated (BE <0)
Caused by:
Gas trapping (COPD, severe asthma)
Chest wall deformities
Muscle weakness
Respiratory depression (opioids etc)
What is COPD?
Chronic obstructive pulmonary disease
A smoking related disease characterised by airflow obstruction - FEV1/FVC <0.7
- Normally the adjacent alveoli help to hold airways open.
- As the airways become scarred and damaged due to smoking, the alveoli walls break down, and the airways lose their integrity.
- This means the airways collapse, trapping air in certain alveoli.
- This means parts of lungs don’t contribute to respiration, so the patient has to fight to get get enough air.
- This leads to hyperinflation.
The major differential for COPD is asthma, how can we differentiate?
COPD; all have smoking history
Onset >35
Cough is productive
Breathlessness is constant
Asthma; onset <35
Nocturnal dyspnoea and wheeze
Diurnal and day-to-day variability in symptoms
How does the body compensate for respiratory failure type 2?
Kidneys reabsorb more bicarbonate
What are the signs of hypercapnia? (As in respiratory failure type 2)
Coma Confusion Drowsiness Dilated pupils(SNS) Bounding pulse Myoclonus Hand flap
Why do people with COPD develop complications?
COPD is an inflammatory process, the inflammatory agents spill over in to the system, combined with the decreased physical activity and hypoxia, it leads to:
Osteopenia Skeletal muscle weakness Depression Metabolic disease - diabetes Cardiovascular diseases
What are the cardinal symptoms of acute exacerbation of COPD?
Cough
Purulent sputum
Fever
What are the most common causes of acute exacerbation of COPD?
Rhinovirus and other viruses = 50%
H.Influenzae (80%) and streptococcus pneumoniae and other bacteria = 50%
What is pneumonia?
An acute infection of the lung parenchyma
MOA:
Neutrophil infiltration
Inflammatory exudate in the interstitium (drawn out by neutrophils)
Alveolar oedema and haemorrhaging
- causing the inflammation, swelling and bleeding in the lungs, which is why CXR shows consolidation
The next step after infection, is either resolution, or incomplete resolution: abscess formation or fibrosis
What is the different between typical and atypical bacterial pneumonias?
Typical organisms are extracellular and can be cultured in the laboratory by standard methods.
Atypical organisms are intracellular, and cannot cultured by standard methods.
They also require antibiotics that can get in to the intracellular space. (Ciprofloxacin, and the macrolides: azithromycin, clarithromycin)
What is the commonest cause of viral pneumonia?
Haemophilus influenza A and B
Diagnosed via PCR
What is the most common cause of fungal pneumonia?
Pneumocystis Jirovecii
Mainly seen in those with altered immunity (e.g. HIV and immunosuppression) but also in those with severe underlying respiratory condition (COPD, CF).
What is hospital acquired pneumonia?
New onset symptoms with compatible X-ray, which develop more than 48 hours after admission to hospital.
It’s still CAP if it’s within 48 hours of admission.
Types of HAP:
Early onset = within 4/5 days of admission, requires cefuroxime
Late onset = >5 days after admission, and is likely to be antibiotic-resistant, so requires pipericillin and tazobactam
Causes: Enterobactericae and staph A
What is community acquired pneumonia?
Signs of a lower respiratory tract infection (fever, cough, phlegm, crepitations, bronchial breathing) with CXR changes.
Diagnosis then requires CURB-65 score to be taken to check danger of death. (Confusion, blood urea, resp rate, low BP and 65+)
Causes: S pneumoniae Haem Influenzae Moraxella catarrhalis Viruses (Influenza A/B, human metpneumovirus and respiratory syncytial virus)
Atypical - mycoplasma pneumoniae and Legionella pneumophilia
What are the atypical causes of pneumonia?
Bacteria:
Mycoplasma pneumoniae
Legionella pneumophilia
Fungi: Aspergillosis fumigatus Zygomycetes Pneumocystis jirovecii Histoplasmosis capsulatam
What type of organism causes pneumonia in the immunocompromised?
Pneumocystis jirovecii
How can you differentiate chlamydia psittaci from other pneumonias?
Expect the patient to have contact with birds - often parrots.
Chest X-ray will show patchy consolidation.
How can you differentiate chlamydophilia pneumoniae from other pneumonias?
A biphasic disease:
First - the ears, pharynx and throat are affected; otitis, pharyngitis and hoarseness
Second - Pneumonia occurs
Early phase and late phase
Second most common cause of CAP
What may make you suspect Legionella pneumophilia may be the cause of pneumonia?
Occurs in outbreaks, especially at hotels
Hyponatremia
Lymphopenia
Deranged LFT’s
Urine test shows haematuria
CXR shows bilateral basal consolidation
Complications: Renal failure, confusion, coma,
How can you differentiate mycoplasma pneumoniae from other pneumonias?
Occurs as epidemics
CXR occurs in ONE lobe, in the lower lobe
How can you differentiate pseudomonas from other pneumonias?
Patients will have underlying condition cystic fibrosis or bronchiectasis
How can you differentiate staphylococcal pneumonia’s from other pneumonias?
Chest X-ray will show BILATERAL cavitating bronchopneumonia (most common organism to cause cavitation)
- showing as a subtle area of radiolucency superimposed on a region of consolidation
What is the most common cause of COPD exacerbation and infection in bronchiectasis?
H. Influenzae
The mucus pools form a nidus for bacterial colonisation in both
What is bronchiectasis?
Dilation of the bronchi due to inflammation, causing bronchial wall oedema and increased mucus production
The mucus pools form a nidus for bacterial colonisation
What are the general symptoms of pneumonia?
Cough; purulent or haemoptysis Fever Rigors Anorexia Chest pain; pleuritic and sudden onset Dyspnoea Abdominal pain; epigastric
What are the general signs of pneumonia?
Pyrexia Tachypnoea Focal crackles, bronchial breathing, whispering pectoriloquy (whispered sounds are louder), and aegophony (voice sounds are more resonant)on auscultation Dull to percussion Confusion
Which type of organism is more likely to affect someone with B cell lymphoma?
S pneumoniae - because the B cells are absent, which means there is limited humoral immune protection, and favours a capsular bacteria like this.
Capsular bacteria are classic bacteria, therefore humoral immunity defends against them.
Unlike viral or fungal organisms, which are dealt with by cell-mediated (T-cell: learning cells)
Why are fungal and atypical bacteria more likely to cause pneumonia in a patient with HIV?
The cell mediated immune system is made up of T cells, this recognises viral and fungal organisms. In HIV patients, their T cells are destroyed.
Who should be give the pneumococcal vaccine or the influenza vaccine?
Pneumococcal: single dose to those over 65, and those under 1
Influenza: Chronic resp disease Chronic heart disease Chronic kidney disease Chronic neurological disease Chronic liver disease DM Immunosuppression Asplenic people Pregnant women Morbidly obese 40kgm2+ Children age 2-10 Residential home dwellers All healthcare workers All those over 65
What is TB?
A mycobacterium that is usually pulmonary (50%), generally tuberculosis or bovis.
MOA: Infection occurs by droplets inhaled, infects macrophages, causing a small primary lung lesion, and then spreads via blood, the lesions (granuloma) heal once the immune system adapts causing a latent stage, then reactivation can occur.
Causing a set of signs that are fever, anorexia, night sweats, clubbing, erythema nodosum (dark patches) and weight loss (similar to HIV/cancer).
Then depends on the site of infection:
(50%) Pulmonary - cough, pleurisy, pleural effusion, cavitation/pneumothorax/atelactasis on cxr (destructive inflammation)
(20%) Lymphadenitis - cervical lymph node enlargement, firm, non tender
(9%) Intrathoracic but not pulmonary
(6.9%) Pleural
Can occur in ANY part of body except kidneys.
(3%) Other types: GI, Spinal (bony), Miliary (loads of little ones on lungs - millet; bird seed), CNS (meningitis), GU, Cardiac or skin
