Lower Respiratory tract infections: Pathology etc - pneumonia and all those ones Flashcards
What are the main LRTIs seen clinically?
ACUTE bronchitis
Exacerbation of COPD
Pneumonia
Empyema
Lung abscess
Bronchiectasis
What is the incidence rate of pneumonia in the UK?
5-11 people per 1000 adult population
What is the mortality rate of hospitalised patients with pneumonia?
5.7 - 12%
What are the symptoms of pneumonia?
Malaise Myalgia Fever Pleuritic (chest) pain Cough Purulent sputum Dyspnoea
What is myalgia?
Pain in a (group of) muscle(s)
What is malaise?
General feeling of illness or discomfort
What is Dyspnoea?
Difficulty breathing
What is the appearance of ‘purulent’ sputum with someone with pneumonia?
Off-white to rusty to green colour
What are the main signs of pneumonia on examination?
Pyrexia
Tachpnoea
Central cyanosis
Dullness on percussion of affected lobes
Bronchial breath sounds
Inspiratory crepitations
Increased vocal resonance
What are the main investigations for pneumonia?
Serum biochemistry, CRP and full blood count
CXR
Blood cultures
Throat swab (for atypical pathogens)
Urinary legionella antigen test
Sputum microscopy and culture
HIV test
Where is pneumonia typically located in the lung(s) and why?
Lower lobes
Gravity innit
Pneumonia caused by inhalation of something normally affects which lung?
Why?
Right lung
Primary bronchus of RL is more vertical than LL’s so stuff goes down there easier
Which microorganism most commonly causes pneumonia?
How prevalent?
Strep pneumoniae
39%
What are the most common causes of pneumonia? >5.2%
microorganisms
(in order)
Strep. pneumoniae - 39%
Chlamydophila. pneumoniae - 13.1%
All viruses - 13.1%
Mycoplasma. pneumoniae - 10.8%
H. influenzae - 5.2%
What is the common clinical name given to Strep. pneumoniae?
Pneumococcus
What is the appearance of pneumococcus under a microscope?
Chains of oval-ee shaped bacteria
gram positive so they’d stain purple
What is the scoring method for severity of pneumonia?
CURB 65
What are the parameters for CURB 65 scoring?
C - confusion?
U - Blood urea >7?
R - Respiratory rate >30?
B - diastolic blood pressure >60?
65 - Age>65?
What are the different score bands for CURB65?
0 = They’re chillybeans
1-2 = Hospital treatment usually required
3-5 = high risk of death and need for ITU
Treatment for CURB 0-1?
Amoxycillin or clarithromycin / doxycycline
+ ‘other treatments’
Treatment for CURB 2?
Amoxycillin and clarithromycin or levofloxacin
+ ‘other treatments’
Treatment for CURB 3-5?
Co-amoxyclav and clarithromycin or levofloxacin
+ ‘other treatments’
Why would levofloxacin be used instead of amoxycillin etc?
If the patient is allergic to penicillins
What is the situation and treatment for aspiration pneumonia?
Amoxycillin and metronidazole
Metronidazole needed because aspiration pneumonia often has anaerobes
Treatment for haematological malignancy / neutropenia?
Broad spectrum antibiotics
Consider anti-fungals
Aside from normal treatment, what should be considered when a patient has legionnaires disease?
Consider involving public health
If a patient has influenza
What would be expected to be seen on their bacterial culture?
High frequency of pneumococcus
Some patients with pneumonia have been infected by MRSA
How is this treated?
Vancomycin or linezolid
If someone has HIV, what is the most likely type of pneumonia they will have?
PJP
(aka PCP)
(Pneumocystis jiroveci Pneumonia)
Aside from pure throwing drugs at them
What are the ‘other treatments’ for patients with pneumonia?
Oxygen
IV fluids
CPAP (ventilator)
Intubation + ventilation
What are the main complications seen with pneumonia?
Septicaemia Acute kidney injury Empyema Lung abscess Metastatic infection ARDS
What is septicaemia?
Infection of blood
What is empyema?
Collection of pus in the pleural cavity
What is ARDS?
Acute resp. distress syndrome
Basically a rapid onset/spread of infection through the lungs
Many patients presenting with respiratory problems show similar symptoms but for different diseases/conditions
What are important differential diagnoses to check?
Tuberculosis
Lung cancer
Pulm. embolism
Pulm. oedema
Pulm. vasculitis (Wegners granulomatosis)
Both pneumonia and pulm. oedema involve fluid in the lungs…
How is pulmonary oedema different from pneumonia?
Causes: Pneumonia is infection based whereas PO is linked to heart failure
PO doesn’t really involve any microorganisms or infection so the lungs are still sterile
How does empyema look on a CXR?
Large area of cloudy-ness across whole of the pleural cavity/lung
What are the main causes of empyema?
Bacterial infection by:
- Streptococcus 52%
- Staph. aureus 11%
- Anaerobes 20%
or Secondary to pneumonia infection
What are the main symptoms/signs of empyema?
Pleuritic (chest) pain
High swinging fever
ABSENCE of cough
What is the investigative/diagnostic route for empyema?
CT thorax & Pleural ultrasound
Diagnosed by Pleural aspiration (ph <7.2)
How is empyema treated?
Chest drain
IV antibiotics (may be prolonged >6 weeks)
Intrapleural t-PA / DNase sometimes required
Surgery for patients not improving with above management.
What organisms are most likely to be found in a lung abscess?
Staph. aureus
Pseudomonas
Anaerobes
Why are lung abscesses sometimes hard to predict from patient’s presenting complaints?
Non-specific symptoms
Usually things like lethargy, weight loss, high swinging fever + normal resp disease symptoms
What is the investigative route for lung abscess?
CT thorax
Sputum culture (including TB culture/microscopy)
What is the treatment route for a lung abscess?
Prolonged antibiotics
Drainage via bronchial tree, but occasionally percutaneous drainage may be necessary
What is bronchiectasis?
airways of the lungs become abnormally widened, leading to a build-up of excess mucus that can make the lungs more vulnerable to infection
What are the causes of bronchiectasis?
Idiopathic
Immotile Cilia Syndrome
Cystic fibrosis
Childhood infections such as measles
Hypogammaglobulinaemia
Allergic Bronchopulmonary Aspergillosis (ABPA)
What are the symptoms of bronchiectasis?
Chronic cough
Daily sputum production (often shite tons)
Sometimes,
- Wheeze
- Dyspnoea
- Tiredness
- Flitting chest pains
- Haemoptysis
What are the main signs of bronchiectasis?
Finger clubbing
Course inspiratory crepitations (auscultation)
How should bronchiectasis be investigated?
High resolution CT thorax
Sputum culture
Serum immunoglobulins
Total IgE and Aspergillus precipitins
CF genotyping
What microorganisms are typical to bronchiectasis?
Haemophilus influenzae
Staph aureus
Pseudomonas aeruginosa
How is bronchiectasis treated?
Appropriate antibiotics
May require inhaled beta2 agonist and inhaled corticosteroid
Chest physiotherapy
