Pneumonia

Question 1

What is pneumonia?

Answer 1

Pneumonia is an infection that inflames the air sacs in one or both lungs. The air sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and difficulty breathing. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.

Question 2

What is bacterial pneumonia?

Answer 2

is most commonly caused by the Streptococcus pneumoniae bacterium, but there are other bacteria that can cause pneumonia. It usually happens when the body is weakened, for example by illness, being elderly, or lowered immunity, but it can happen to anyone. The germs that cause bacterial pneumonia can be passed on from person to person.

Question 3

What is viral pneumonia?

Answer 3

Viral pneumonia is caused by viruses like influenza (the flu virus) and RSV (respiratory syncytial virus). RSV is most often the cause of viral pneumonia in children. COVID-19 pneumonia is a form of viral pneumonia that happens as a complication of COVID-19. The germs that cause viral pneumonia can be passed on from person to person.

Question 4

What aspiration pneumonia?

Answer 4

which is caused by food going down your windpipe instead of the tube that goes to your stomach (the oesophagus), or by breathing in vomit, a foreign object or a harmful substance, like smoke or chemicals. It’s most common in people who already have a condition affecting their brain or their ability to swallow.

Question 5

What is fungal pneumonia?

Answer 5

which is caused by a fungal infection. It’s rare in the UK and more likely to affect people with a weakened immune system.

Question 6

What is hospital-acquired pneumonia?

Answer 6

HAP is defined as a lower respiratory tract infection acquired after 48 hours of hospital admission, which was not incubating at the time of admission

Question 7

What is community-acquired pneumonia?

Answer 7

Pneumonia that starts outside of hospital

symptoms and signs consistent with an acute lower respiratory tract infection associated with new radiographic shadowing for which there is no other explanation, occurring outside of the hospital or healthcare setting.

Question 8

What pathogen accounts for 80% of cases of pneumonia?

Answer 8

Streptococcus pneumoniae

Particularly associated with high fever, rapid onset and herpes labialis
A vaccine to pneumococcus is available

Question 9

What pathogen that causes pneumonia are common in patients with COPD?

Answer 9

Haemophilus influenzae

Question 10

What pathogen often occurs in patients following an influenza infection?

Answer 10

Staphylococcus aureus

Question 11

What are characteristics of Mycoplasma pneumoniae?

Answer 11

One of the atypical pneumonias, which often present a dry cough and atypical chest signs/x-ray findings
Autoimmune haemolytic anaemia and erythema multiforme may be seen

Slow-onset history over a few days or weeks
May present as a sore throat, lethargy, headache, nausea, abdominal pain and diarrhoea in young adults
Persistent dry and hacking cough
Typically resolves spontaneously over a few weeks in healthy patients

Question 12

What are characteristics of Legionella pneumophilia?

Answer 12

Typically associated with a contaminated water supply, i.e., poorly maintained air-conditioning or humification systems
Incubation period 2-10 days
Cough is prominent, with dyspnoea and pleuritic chest pain common
Gastrointestinal upset with diarrhoea and vomiting is also seen
Neurological disruption, including confusion, is more common than with other pneumonia
Arthralgia and myalgia are often reported
Can precipitate hyponatraemia

Question 13

Which pathogen of pneumonia is typically seen in alcoholics?

Answer 13

Klebsiella pneumoniae

Question 14

Which pathogen of pneumonia is typically seen in patients with HIV?

Answer 14

Pneumocystis jiroveci

Presents with a dry cough, exercise-induced desaturations and the absence of chest signs

Question 15

What is idiopathic interstitial pneumonia?

Answer 15

Idiopathic interstitial pneumonia is a group of non-infective causes of pneumonia. Examples include cryptogenic organizing pneumonia which describes a form of bronchiolitis that may develop as a complication of rheumatoid arthritis or amiodarone therapy.

Question 16

What are common symptoms of pneumonia?

Answer 16

cough
sputum
dyspnoea
chest pain: may be pleuritic
fever and rigors
confusion
Constitutional features: including lethargy, malaise, myalgia, anorexia, and headache

Question 17

What is the incidence rate of community-required pneumonia?

Answer 17

he annual incidence of community-acquired pneumonia in the UK is estimated at 5-10 per thousand adults.

Question 18

What percent of those who have community-acquired pneumonia

Answer 18

The proportion of UK adults requiring hospitalisation due to community-acquired pneumonia is between 22-42%, with a mortality rate 5-14%

Question 19

What are the two types of bacterial pneumonia?

Answer 19

1. Typical
2. Atypical

Question 20

What is defined as typical pneumonia?

Answer 20

Typical bacterial pneumonia is caused by the most common organisms associated with pneumonia. Streptococcus pneumoniae is the leading bacterial cause of CAP across a range of age groups.5

Other bacterial causes include Haemophilus influenzae, Staphylococcus aureus (including MRSA), and Moxarella catarrhalis.6 However, mixed pathogens are not uncommon.

Question 21

What is defined as atypical pneumonia?

Answer 21

Atypical bacterial pneumonia is caused by less common organisms that may be more challenging to diagnose or may be associated with specific patient populations. The most commonly reported atypical bacteria are Mycoplasma pneumoniae, Chlamydophila pneumoniae, and Legionella pneumophila.

Question 22

What are the most common viral causes of community-acquired pneumonia?

Answer 22

1. Influenza A+B

other causes:
severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rhinoviruses, parainfluenza viruses, adenoviruses, respiratory syncytial virus and other coronaviruses

Question 23

What causative organisms in HAP are typically more present in the hospital environment?

Answer 23

These usually include gram-negative bacilli (Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia) and gram-positive cocci (Streptococcus pneumoniae, Staphylococcus aureus (including MRSA)).11

S. pneumoniae is the most prominent bacteria in infections occurring within the first five days of admission.11

Question 24

What is ventilator-associated pneumonia defined as?

Answer 24

Ventilator-associated pneumonia is defined as occurring 48 – 72 hours after tracheal intubation. The causative organisms are similar to those of HAP.

Question 25

What types of patients is aspiration pneumonia more common in?

Answer 25

1. Those with swallowing dysfunction
2. Those undergoing general anaesthesia
3. those with delayed gastric emptying
4. Those with a poor cough

Question 26

What are risk factors for pneumonia?

Answer 26

1. Age- particularly infants/children and those >65
2. Smoking
3. Alcohol use
4. Pre-existing respiratory conditions
5. Intravenous drug use
6. Hospitalisation
7. Proton-pump inhibitors - thought to be secondary to increased upper airway colonisation due to reduced gastric acid secretion
8. Poor oral hygiene
9. Child contacts

Question 27

What are the characteristics of Chlamydophila pneumoniae?

Answer 27

Gradual onset, which may show improvement before worsening again
Incubation period can be 3-4 weeks
Non-specific respiratory tract symptoms, including cough and wheezing
Productive cough with scanty, watery sputum
Most remain well or are asymptomatic

Question 28

What vital signs are expected in a patient with pneumonia?

Answer 28

tachypnoea, hypoxia, and tachycardia may all be present

Question 29

What may be found after auscultation and percussion?

Answer 29

Course crackles and/or decreased breath sounds: on auscultation of the chest

Wheeze
Dullness to percussion: over the affected area of the chest wall

Question 30

What differential diagnoses should be considered in suspected pneumonia?

Answer 30

1. Upper respiratory tract infection
2. Exacerbation of COPD
3. Exacerbation of Asthma
4. Congestive heart failure
5. COVID
6. Tuberculosis
7. Lung Cancer
8. Empyema
9. PE

Question 31

What bedside investigations should be carried out for suspected pneumonia?

Answer 31

Basic observations: to assess for hypoxia, fever, tachypnoea, tachycardia and hypotension (in septic shock)

Polymerase chain reaction (PCR) test: this allows for the rapid identification of various organisms, depending on the test, i.e., an extended viral screen including SARS-CoV-2

Question 32

What laboratory investigation can be carried out and what should be expected to see?

Answer 32

Full blood count: may demonstrate a raised white cell count.

C-reactive protein (CRP): elevated in infection and can be used to aid prognosis.

Urea and electrolytes: urea is part of the CURB-65 severity score, and patients may present with a comorbid acute kidney injury. Hyponatraemia may be seen in Legionella.

Liver function tests: baseline hepatic function for antibiotic treatment. These may be deranged in Legionella

Sputum culture: ideally taken before starting antibiotics, with antibiotics optimised based on sensitivities. The sample should be expedited to microbiology to prevent degradation.

Blood cultures: should be requested in all patients with moderate or high-severity pneumonia. Ideally, cultures should be taken before antibiotics are given. Antibiotics should then be optimised based on sensitivities.

Arterial blood gas: recommended in hypoxic patients, those at risk of hypercapnia or who are graded as high-risk pneumonia, depending on the patient it may show type 1 or type 2 respiratory failure.

Legionella and pneumococcal urinary antigen: this should be requested in those with moderate or high-severity CAP or where other risk factors exist.

Question 33

What imaging can be used to diagnose pneumonia?

Answer 33

1. Chest X-ray - evidence of consolidation is seen
2. CT thorax - this is only considered where there is diagnostic doubt or if a chest X-ray suggests abnormalities which require further imaging.

Question 34

What is the CURB-65 score used for?

Answer 34

To calculate the severity of community-acquired pneumonia

Question 35

What does CURB-65 stand for?

Answer 35

Confusion: new onset, which may be defined as an abbreviated mental test (AMT-10) score ≤8

Urea: of >7 mmol/L
Respiratory rate: ≥30 breaths/minute

Blood pressure: <90 mmHg systolic or ≤60 mmHg diastolic

Age: ≥65 years

Question 36

What does a score of 0-1 on the CURB-65 score indicate?

Answer 36

low risk

Consider outpatient treatment

Question 37

What does a score of 2 on the CURB-65 scale mean?

Answer 37

moderate risk

Consider inpatient or hospital-supervised outpatient treatment

Question 38

What does a score of 3-5 on the CURB-65 scale indicate?

Answer 38

high risk

Admission for inpatient treatment with consideration for discussion with critical care if achieving the higher end of the range

Question 39

What does acute management of pneumonia consist of?

Answer 39

supportive measures, such as rest and oral hydration, alongside medical management, such as antibiotics
Patients well enough to remain in the community can generally be managed with supportive measures and oral antibiotics.

Question 40

What is the management of acutely unwell patients with pneumonia?

Answer 40

Oxygen: to maintain appropriate oxygen saturations.
Intravenous fluids: rate and volume dependent on the clinical stability and degree of volume depletion.

Analgesia and antipyretics: simple analgesia such as paracetamol and non-steroidal anti-inflammatory drugs (providing no contraindications) or a weak opioid (e.g., codeine), if required.

Venous thromboembolism (VTE) prophylaxis: all hospitalised patients should undergo a VTE risk assessment and receive appropriate prophylaxis.

Question 41

What is the first line of antibiotics for community-acquired low-severity pneumonia?

Answer 41

First choice oral antibiotic:

Amoxicillin: 500 mg – 1 g three times a day
Alternative oral antibiotics:

Doxycycline: 200 mg on day one, then 100 mg a day
Clarithromycin: 500 mg twice a day

Question 42

What is the first line of antibiotics for community-acquired moderate-severity pneumonia?

Answer 42

First choice combination of:

Amoxicillin: 500 mg – 1 g three times a day
Clarithromycin: 500 mg twice a day
Alternative oral antibiotics:

Doxycycline: 200 mg on day one, then 100 mg a day
Clarithromycin: 500 mg twice a day
Erythromycin (in pregnancy): 500 mg four times a day

Question 43

What is the first line of antibiotics for community-acquired high-severity pneumonia?

Answer 43

First choice combination of:

Co-amoxiclav: 500/125 mg three times a day orally, or 1.2 g three times a day IV
Clarithromycin: 500 mg twice a day

Question 44

What is the first line antibiotic for non-severe hospital-acquired pneumonia?

Answer 44

First choice oral antibiotic:

Co-amoxiclav: 500/125 mg three times a day orally

Alternative oral antibiotics:

Co-trimoxazole: 960 mg twice a day
Doxycycline: 200 mg on day one, then 100 mg a day