Lobar Pneumonia Flashcards
What is pneumonia?
What usually causes it?
it is a common lower respiratory tract infection, characterised by inflammation of lung tissue
it is almost always an acute infection and almost always caused by bacteria
diagnosis is typically confirmed by chest X-ray
For what age group is pneumonia particularly dangerous?
it is responsible for many deaths of patients over the age of 80
deaths amongst younger populations have dramatically decreased after introduction of antibiotics
What is the incidence of pneumonia?
Amongst which particular group is the incidence of bacterial pneumonia higher?
incidence is 1 - 3 per 1,000
(0.1 - 0.3% of people have pneumonia at any one time)
incidence of bacterial pneumonia is higher amongst those with HIV , particularly IV drug users with HIV
the causatory organisms remain the same
What % of pneumonia cases are viral?
most cases are caused by bacteria
around 15% are viral
How can pneumonia be classified by anatomical location?
Localised pneumonia:
- affects just one particular lobe
Bronchopneumonia:
- this is a more diffuse pneumonia that affects the lobules and bronchioles
How can pneumonia be classified by aetiology?
Pneumococcal pneumonia:
- accounts for 75% of cases
Atypical pneumonia:
- accounts for 20% of cases
- caused by atypical organisms such as Chlamydia, legionella or coxiella burnetti
- the infection itself tends to have similar symptoms
If 75% of cases are pneumococcal and 20% are atypical, what are the other 5% of cases caused by?
- aspiration of vomit
- radiotherapy
- allergic mechanisms
What is the most useful way to classify pneumonia?
the most useful distinction is between community acquired and hospital acquired pneumonia
the difference between the two is in the causatory organism
What is the definition of hospital acquired pneumonia?
pneumonia that develops within 48 hours of hospital admission
What is the prognosis like for community and hospital acquired pneumonia?
Community acquired:
- prognosis generally good for younger patients
- S. pneumoniae and viral pneumonias are still fatal in older patients
Hospital acquired:
- prognosis generally poor due to co-morbidities, older age range of patients and resistance of organisms
What are common organisms that cause community acquired and hospital acquired pneumonia?
Community acquired:
- Streptococcus pneumoniae
- Haemophilus influenzae
- anaerobes are rare
Hospital acquired:
- Gram negative bacilli
- Staphylococcus aureus
- Drug resistant organisms are more common and more dangerous
What rare organisms can cause community acquired pneumonia?
-
Chlamydia pneumoniae
- common in institutions e.g. colleges, military camps
- Mycoplasma pneumoniae
- Legionella
What does a strep pneumoniae infection often follow on from?
strep pneumoniae infection often follows viral infection with influenza or parainfluenza
What are the precipitating factors for pneumonia?
- Strep pneumoniae infection follows on from influenza or parainfluenza
-
hospital admission
- hospital acquired infection is associated with Gram-negative organisms
-
cigarette smoking
- this is the most important risk factor in pneumococcal disease
- alcohol excess
- bronchiectasis (e.g. in CF)
- bronchial obstruction (e.g. carcinoma)
- immunosuppression
- IV drug use
- dysphagia (leads to aspiration)
How are symptoms of pneumonia different in hospital acquired and community acquired cases?
symptoms are typically the same
increased secretions are noticeable in ventilated hospital acquired cases
What symptoms does pneumonia usually present with?
- shortness of breath
- cough
- fever
- rigors
- vomiting
- headache
- loss of appetite
- pleuritic chest pain
- dyspnoea
- tachypnoea
- tachycardia
What type of cough does pneumonia typically present with?
the cough tends to be productive in adolescents and adults and may produce purulent sputum
it tends to be dry in infants and the elderly
What is pleuritic chest pain?
Where can it radiate to?
a sharp shooting or stabbing pain, usually in the side
it is most painful on inspiration, but can also be felt on expiration or even whilst talking
it can radiate to the shoulder (if diaphragm is involved) or to the anterior abdominal wall
What symptom may be present in patients with lower lobe pneumonia?
upper abdominal tenderness
What respiratory symptom is rarely present in pneumonia?
haemoptysis is very rarely present
What signs are present in pneumonia?
there will be signs of consolidation on examination and CXR
- ipsilateral reduced chest expansion
- dull to percussion
- reduced breath sounds due to reduced air entry into that region of the lung
- coarse crackles
What signs may be present in pneumonia caused by strep pneumoniae?
- rapid shallow breathing
-
pleural friction rub
- squeaking / grating sound of the pleural linings rubbing together
- sounds like treading on fresh snow
- occurs when pleural layers are inflamed and have lost their lubrication
What sign of pneumonia may be present in elderly patients?
sometimes confusion is the only sign present in elderly patients
When should we be concerned about oxygen saturation?
<92% is worrying
What is performed following clinical suspicion of pneumonia and what should it show?
a CXR is performed to confirm the diangosis
this shows the evidence of infiltrate in the form of consolidation
it can also show the spread of any infection by distribution of the infiltrate
When can consolidation be visible on a pneumonia CXR?
changes may not appear on CXR for up to 48 hours after symptoms
after effective treatment, consolidation may still be visible on X-ray for up to 6 weeks
How often should CXR be repeated for pneumonia patients and why?
- CXR should be repeated at least weekly for inpatients
- they should then be repeated every 6 weeks as an outpatient
- any signs still present indicate the need for a further X-ray
- persistent X-ray changes may suggest underlying carcinoma with secondary pneumonia
Why may blood cultures be taken?
blood cultures are taken to assess for bacteraemia
it is not routine practice to identify the causatory organism in community acquired infection
What would a full blood count for pneumonia show?
- raised WCC
- raised ESR (>100 mm/h) and raised CRP
- possible anaemia (sign of abscess)
- blood cultures are taken in ill patients to assess for septicaemia
When might urine samples be taken in pneumonia?
in severe cases of pneumonia, where legionella is suspected
urine testing for legionella antigen may be performed
When might pleural fluid aspiration be performed in pneumonia?
to assess for organisms
transthoracic aspiration may be performed (often with CT guidance) to identify lesions (e.g. empyema abscess) and to gain samples
What is used to assess the severity of community-acquired pneumonia?
CURB-65 score
this predicts the risk of mortality
(CURB score 0 = <1% risk - CURB score 5 = 60% risk)
each factor of the score is worth 1 point
How is the CURB-65 score measured?
C - CONFUSION:
- use the abbreviated mental test (score = 8)
U - UREA:
- > 7mmol/L
R - RESPIRATORY RATE:
- >/= 30 / min
B - BLOOD PRESSURE:
- < 90 systolic or <60 diastolic
65 - AGE:
- age > 65 years
a score of 3 or more is severe pneumonia
a score of 2 or more requires hospitalisation
What are the differential diagnoses of pneumonia?
- pulmonary oedema
- tuberculosis
- pulmonary embolism
- patient is not usually systemically unwell
- SOB more likely to be sudden onset
When are antibiotics given to treat pneumonia?
- oral antibiotics are given if patient is NOT vomiting and CURB65 score = 2
- IV antibiotics are given if patient is vomiting and/or CURB65 score is >/= 3
What other treatments should be in place for pneumonia?
- oxygen therapy is required to keep O2 sats > 92%
- IV fluids are given to prevent dehydration and shock
- progress is monitored via repeat CXRs
- all patients should receive a 6-week follow up including repeat CXR
How and when should complications of pneumonia be assessed for?
in any patient who is not responding to treatment appropriately, CXR and FBC should be repeated to assess for complications
CRP is of particular importance
What are the 3 immediate complications of pneumonia?
these are present at presentation or within a few days
- respiratory failure (most common)
- hypotension
- atrial fibrillation
How is respiratory failure measured and treated?
What should sats be?
respiratory failure is present when PaO2 < 8 kPa
it is relatively easy to treat with 60% (high flow) oxygen
sats are aimed to be kept between 90 - 94%
When should someone with respiratory failure be transferred to ICU?
In what patients should extra caution be taken?
if PaCO2 rises to >6 kPa or hypoxia does not resolve with oxygen therapy, then transfer to ICU
be careful using O2 in COPD patients as it can reduce hypoxic drive
regular ABG testing should be performed and intubation considered if situation is not improving
Why does hypotension occur as a complication of pneumonia?
How is it treated?
it is the result of dehydration and vasodilation due to sepsis
it should be treated when systolic blood pressure drops below 90 mmHg
it is treated with 250ml of crystalline infusion over 15mins
When does atrial fibrillation tend to occur as a complication of pneumonia?
How is it treated?
it is a common complication in the elderly
it usually resolves with the treatment of pneumonia, but digoxin can be given to reduce the HR as a short-term therapy
What are the 5 different medium term complications associated with pneumonia?
these occur within days of initial presentation
- pleural effusion
- empyema
- lobar collapse
- thromboembolism
- pneumothorax
How can pleural effusion result from pneumonia?
How is it treated?
the pleura may become inflamed, which can result in excess fluid production, causing a pleural effusion
it often does not require treatment
in some individuals, it may require drainage
When are clinical signs present for a pleural effusion?
clinical signs are not usually present until the volume of fluid is >500ml
rarely, the fluid can become infected, resulting in empyema
When does empyema tend to affect a pneumonia patient?
How does it present?
typically presents in a patient who has partially recovered, but then develops a spike in temperature
signs of pleural effusion may be present:
- decreased chest expansion
- dullness to percussion
- reduced breath sounds
- pleural rub
- all on the affected side
What does the fluid look like following fluid aspiration in empyema?
How are samples obtained and what type of bacteria are usually present?
fluid is usually yellow, with a pH <7.2 and low levels of glucose
samples are obtained via aspiration, bronchoscopy or transthoracic aspiration using USS/CT guidance
70% of cases of empyema consist purely of anaerobes
30% of cases of empyema have both aerobic and anaerobic bacteria present
What is the primary treatment method for empyema?
treatment is with the insertion of a chest drain, usually with radiological guidance
What antibiotic therapy is given for the treatment of empyema?
- antibiotics are given for 4 - 6 weeks
- it needs to be something that is effective against both aerobic and anaerobic bacteria
- typically IV cefuroxime and co-amoxiclav for 5 days followed by 3-5 weeks of metronidazole alone
Why can lobar collapse occur as a complication of pneumonia?
this is most commonly the result of sputum retention
When does pneumothorax tend to occur as a complication of pneumonia?
it is particularly associated with Staphylococcus aureus as a causative organism
What are the 5 main categories of late complications of pneumonia?
these occur within days to weeks of initial presentation
- lung abscess
- septicaemia
- ARDS / renal failure / multi-organ failure
- ectopic abscess
- hepatitis, pericarditis, myocarditis & meningitis
What is a lung abscess?
What can it commonly result from?
it is a cavitating lesion containing pus, within the lung
it commonly results from aspiration (e.g. alcoholism, inhaled foreign body, oesophageal blockage, bulbar palsy)
it also occurs in bronchial obstruction (e.g. carcinoma)
it is most likely to occur if pneumonia is not adequately treated
What organisms are more likely to cause a lung abscess?
some organisms are more likely to cause an abscess than others
such as Staphyloccocus aureus and Klebsiella pneumoniae
sometimes, septic emboli, particularly in the case of staphylococci, can result in multiple lung abscesses
What else can more rarely lead to lung abscess formation?
pulmonary infarction can cavitate, may become infected, and result in abscess formation
How would a lung abscess as a complication of pneumonia typically present?
- a pneumonia that worsens despite treatment
- production of purulent sputum, as a result of the growth of anaerobic organisms
- likely to be fever, malaise, anaemia and weight loss
- clubbing can occur if the abscess has been present for long enough
What are the investigations for lung abscess?
- CXR - shows a walled cavity, usually with a fluid level
- Bloods - FBC for anaemia & neutrophilia
- ESR & CRP will be raised
- sputum sample - to identify organism
- bronchoscopy is sometimes performed to obtain samples
What are the treatments for lung abscess?
- treat as per antibiotic sensitivities for 4-6 weeks
- consider postural drainage to remove excess sputum
- in severe cases, antibioitc instillation / aspiration and sometimes surgical excision may be required
When can septicaemia occur as a complication of pneumonia?
What can it result in?
can occur if the bacteria enter the bloodstream
can result in infective endocarditis and meningitis
What is the treatment for septicaemia following pneumonia?
the patient will be very systemically unwell and will need IV antibiotics once blood cultures have been performed to identify the causative organism
When are hepatitis, pericarditis, myocarditis and meningitis typically seen as complications of pneumonia?
most commonly seen in mycoplasma pneumoniae infection, which is most prevalent in young adults
In someone with streptococcus pneumoniae infection, how does the pneumonia tend to progress over time?
- very commonly preceded by viral infection
- patient rapidly becomes febrile, with a temperature of up to 39.5C, along with pleuritic pain and cough
- the cough becomes productive over the coming days and produces rust coloured sputum
- breathing may become rapid and shallow with decreased chest expansion on the affected side
- pleural rub may be present
What causes of pneumonia are more common in young people and older people?
- Mycoplasma pneumoniae and Chlamydia pneumoniae are common in the young, but rare in the elderly
- Haemophilus influenzae is common in elderly people, but rare in the young
- viral infections are very common in children
In what group of people is legionella infection more common?
it is more common in those with recent foreign travel
How does acute coryza (the common cold) tend to present itself?
What symptoms are present?
- rapid onset
- burning / tickling sensation in the nose
- sneezing
- sore throat
- blocked nose with watery discharge
- discharge turns green / yellow after 24-48 hours
What are the complications of acute coryza?
- sinusitis
- lower respiratory tract infection (bronchitis / pneumonia)
- hearing impairment / otitis media due to blockage of eustachian tubes
What is the treatment for acute coryza?
- most do not require treatment
- paracetamol 0.5-1g every 4-6 hourly for relief of systemic symptoms
- nasal decongestants may be used
- antibiotics are NOT necessary in uncomplicated coryza
What is acute laryngitis often a complication of?
How does this present?
- often a complication of acute coryza
- dry sore throat with hoarse voice or loss of voice
- attempts to speak cause pain
- initially there is a painful and unproductive cough
What symptom may be present in children with acute laryngitis and why?
stridor in children (croup) due to inflammatory oedema leading to partial obstruction of a small larynx
What are the potential complications of acute laryngitis?
- complications are rare
- chronic laryngitis
- downward spread of infection may cause tracheitis, bronchitis or pneumonia
What are the treatments for acute laryngitis?
- rest the voice
- paracetamol 0.5-1g every 4-6 hourly for relief of discomfort and pyrexia
- steam inhalations
- antibiotics are NOT necessary for acute laryngitis
What is croup?
a childhood viral infection that causes swelling around the larynx (vocal cords), trachea and bronchi
the breathing is obstructed, causing a characteristic barking cough
What are the symptoms of acute laryngo-tracheobronchitis (croup)?
- initial symptoms are like the common cold
- sudden paroxysms of cough accompanied by stridor and breathlessness
- contraction of accessory muscles and indrawing of intercostal spaces
What can happen to small children with croup if appropriate treatment is not given?
cyanosis and asphyxia (suffocation)
What are the potential complications of acute laryngo-tracheobronchitis (croup)?
- asphyxia and death
- superinfection with bacteria, especially Streptococcus pneumoniae and Staphylococcus aureus
- viscid secretions that may occlude the bronchi
What are the treatments for acute laryngo-tracheobronchitis?
- inhalations of steam and humidified air / high concentrations of oxygen
- endotracheal intubation or tracheostomy to relieve laryngeal obstruction and allow clearing of bronchial secretions
- IV antibiotics (co-amoxiclav or erythromycin)
- maintain adequate hydration
How does acute epiglottitis present?
fever and sore throat, rapidly leading to stridor because of swelling of the epiglottis and surrounding structures
stridor and cough in absence of much hoarseness can distinguish acute epiglottitis from other causes of stridor
What organism is usually responsible for swelling of the epiglottis in acute epiglottitis?
Haemophilus influenzae
What are the complications associated with acute epiglottitis?
What should be avoided and why?
- death from asphyxia which may be precipitated by attempts to examine the throat
- avoid using tongue depressor / any instrument unless facilities for endotracheal intubation or tracheostomy are immediately available
What are the treatments for acute epiglottitis?
- IV antibiotics - co-amoxiclav or chloramphenicol
- other measures are the same as for acute laryngo-tracheobronchitis
What does acute bronchitis & tracheitis often follow on from?
What are the initial symptoms?
- often follows acute coryza
- initially presents with irritating unproductive cough accompanied by retrosternal discomfort of tracheitis
- when bronchi become involved, there is chest tightness, wheeze and breathlessness
- tracheitis causes pain on coughing
How does the sputum change in acute bronchitis & tracheitis?
- initially sputum is scanty or mucoid
- after about 1 day, sputum becomes mucopurulent and more copious
- in tracheitis, sputum becomes blood-stained often
What is acute bronchial infection associated with?
How long does it take to recover?
- associated with pyrexia of 38 - 39C and a neutrophil leucocytosis
- spontaneous recovery occurs over a few days
What are the potential complications of acute bronchitis and tracheitis?
- bronchopneumonia
- exacerbation of chronic bronchitis, which often results in type II respiratory failure in patients with severe COPD
- acute exacerbation of bronchial asthma
What treatment is given to ease the cough in acute bronchitis & tracheitis?
Pholcodine
5 - 10 mg every 6-8 hourly
