Lower Respiratory Tract Infections 2 Flashcards
what are the main problems associated with LRTIs?
Acute Bronchitis COPD Exacerbations Pneumonia Empyema Lung Abscess Bronchiectasis
What is acute bronchitis?
A viral infection causing inflammation of trachea & main airways
How does bronchiectasis relate to LRTIs?
It dilates the airways making patients more prone to infection
How common/severe is pneumonia?
5-11 per 1000 people
22-42% requires hospitalisation
5.7-12% mortality in the hospitalised patients
Symptoms of Pneumonia?
Malaise Fever Pleuritic Chest Pain (sharp) Cough Purulent (infected) Sputum Dyspnoea Headache
Why is it difficult to diagnose pneumonia?
Its initial symptoms are very vague and fit other LRTIs.
What are the signs of pneumonia?
- Pyrexia
- Tachypnoea
- Central Cyanosis
- Dullness on Percussion of the affected Lobes
- Bronchial Breath Sounds
- Inspiratory Crackles
- Increased Vocal Resonance
How does increased vocal resonance occur in pneumonia?
Consolidation of the lobe leads to increased vocal resonance.
How do we investigate Pneumonia?
Serum Biochem, FBC (Infection)
CRP (shows inflammation)
CXR (shows degree of consolidation)
Blood Culture (picking out specific pathogen in feverish patients)
Sputum Microscopy/Culture (picking out pathogen)
Throat Swab (for Atypical Pathogens e.g. Viruses)
Urinary Legionella Antigen (To check for Legionnaires disease)
What is legionnaires?
A serious lung infection caused by legionella bacteria.
What are the most common causes of Penumonia?
Strep. Pneumoniae (Gram +ve, Pneumococcus) [36%] H. Influenzae [10.2%] Legionella [0.4%] Staph. Aureus [0.8%] Viruses [13.1%] Mycoplasma Pneumoniae [1.3%] Chlamydia Psittaci [1.3%]
Why dont the common causes of pneumonia add up to near 100%?
In the majority of cases the causative microorganism isnt found.
Which pneumonia causing organisms are atypical?
Chlamydia Psittaci
Mycoplasma Pneumoniae
How would strep Pneumoniae appear under gram staining & Microscopy?
Purple
Balls (cocci) forming chains
What scale do we use to score the severity of penumonia?
The CURB 65 scale. Each letter + 65 stands for a criteria. The number they score determines how to respond.
What are the criteria of the CURB 65 scale?
C - Confusion U - Blood Urea>7 R - Respiratory Rate>30 B - Diastolic BP<60 65 - Age>65 yrs
Do we hospitalize a 0 CURB65 score?
Assume low risk and treat in the community
Do we hospitalise a curb65 score of 1-2?
Usually need hospital level treatment
Do we hospitalise a CURB65 score of 3-5?
Assume a high risk of death and admit to ITU
How do we treat a CURB65 score of 0-1?
Amoxycillin or Clarithromycin/Doxycycline
How do we treat a CURB65 score of 2?
Amoxicillin AND Clarithromycin (or Levofloxacin)
How do we treat a CURB 65 score > 2?
Co-Amoxiclav & Clarithromycin. (Or levofloxacin if penicillin allergic)
Why do we use co-amoxiclav over standard amoxicillin in severe pneumonia cases?
It has a broader spectrum.
Why non-drug treatments do we sometimes give severe pneumonia patients?
Oxygen or if necessary CPAP
I.V. Fluids
In Very severe cases intubation & Ventilation
What are the common complications of Pneumonia?
Septicaemia Acute Kidney Injury Empyema Lung Abscess Haemolytic Anemia (Mycoplasma) ARDS
When do pneumonia patients generally get an Acute Kidney Injury?
When theyre elderly and/or suffer from co-morbidities.
How does Haemolytic Anaemia occur in pneumonia?
In Mycoplasma caused pneumonia an immune phenomenon can cause RBCs to be destroyed.
What do we do if a pneumonia patient develops ARDS?
Transfer to the ICU
What are other conditions that can appear to be Pneumonia?
TB Lung Cancer Pulmonary Embolism Cardiac Failure Pulmonary Vasculitis (Wagners Granulomatosis)
How do we tell TB from pneumonia?
TB tends to infect the upper lobes and generally occurs following something else so the patient will have been unwell for at least several weeks.
How is a pulmonary embolism mistaken for pneumonia?
It can produce infarcts that look like pneumonia, particularly in the elderly
What is Pulmonary Vasculitis?
A term used to describe conditions involving destruction of blood vessels in the lungs.
What is empyema?
Infection in the pleural cavity
What microorganisms tend to cause empyema?
Streptococcus [52%]
Staph. Aureus [11%]
Anaerobes [20%]
How do we tell an empyema apart from other LRTIs?
Chest pain, the lack of a cough and often a high swinging fever.
How do we investigate an Empyema?
A CT of the Thorax
Pleural Ultrasound
How do we diagnose/treat Empyema?
Diagnostic Pleural Aspiration (check if pH is <7.2), then culture.
Then treat with a chest drain & relevant IV Antibiotics
What can we do if an empyema patient doesn’t respond to antibiotics?
The Antibiotics can be extended for longer or surgery is available.
What are the symptoms of a lung abscess?
Pretty non-specific
Lethary, Weight Loss, high swinging fever
How do we investigate a lung abscess?
With a CT Thorax and a sputum culture (including TB culture)
What organisms are likely to cause abscesses?
Staph Aureus
Pseudomonas
Anaerobes
How do we treat a Lung Abscess?
Drain via the bronchial tree (or percutaneously) Then treat with prolonged antibiotics.
What are the most common potential causes of bronchiectasis?
Idiopathic (mainly) Immotile Cilia Syndrome Cystic Fibrosis Childhood infection Hypogammaglobulinaemia Allergic Bronchopulmonary Aspergillosis (ABPA)
How does Cystic fibrosis relate to bronchiectasis?
CF patients often have a severe case of bronchiectasis at a young age.
How do childhood infections relate to Bronchiectasis?
Theres a correlation between childhood infections like measles & whooping cough and bronchiectasis
How does hypogammaglobinaemia lead to bronchiectasis?
Immunoglobulin G isn’t produced so infections are very common.
What does ABPA look like?
ABPA can present like asthma and if chronic lead to bronchiectasis.
What are the symptoms of bronchiectasis?
Chronic Cough
Daily (often large) sputum production
And not always but sometimes:
- Wheeze
- Dyspnoea
- Chronic Tiredness
- Flitting chest pain
- Haemoptysis
What signs are there of bronchiectasis?
Finger Clubbing (generally only in V. Severe cases) Course inspiratory Crepitations
What do we do to investigate Bronchiectasis?
A High Resolution Thorax CT.
Sputum Culture
Serum immunoglobulins (looking for Immunoglobulin G deficiency)
Total IgE & Aspergillus precipitins (Looking for ABPA)
CF genotyping
How does bronchiectasis appear on a HRCT?
Some of the airways will be unusually dilated. Can often compare the two sides
What can we do to treat Bronchiectasis?
Inhaled Beta2 agonists & corticosteroids. (like Asthma)
Chest Physiotherapy.
Promptly treat infections with antibiotics.