Lower respiratory tract infection Flashcards
What is pneumonia?
inflammatory condition affecting the alveoli of the lungs, but in vast majority of patients this is secondary to a bacterial infection
What are 3 types of causes of pneumonia and what is the commonest?
- Bacteria (commonest)
- Viral
- Fungal (e.g. Pneumocystis jiroveci)
What are the top 3 bacterial causes of typical pneumonias? Which is the commonest?
- Streptococcus pneumoniae (commonest - 80%)
- Haemophilus influenzae
- Staphylococcus aureus
What prevention against pneumonia caused by Streptococcus pneumoniae is available?
vaccine to pneumococcus
What are 4 features particularly associated with streptococcus pneumoniae pneumonia?
- High fever
- Rapid onset
- Pleuritic chest pain
- herpes labialis
In which group of patients is Haemophilus influenzae particularly common?
patients with COPD
What are 2 causes of atypical pneumonias?
- Mycoplasma pneumoniae
- Legionella pneumonophilia
What is the type of pneumonia classically seen in alcoholics?
Klebsiella pneumoniae
What is the presentation of mycoplasma pneumoniae?
dry cough and atypical chest signs / x-ray findings
When does Staphylococcus aureus pneumonia commonly occur?
following influenza infection
What are 2 conditions which may be seen with Mycoplasma pneumoinae pneumonia?
- Autoimmune haemolytic anaemia
- Erythema multiforme
What are 2 common features of legionella pneumophilia?
- Hyponatraemia
- Lypmhopenia
What is the classical cause of legionella pneumophilia?
secondary to infected air conditioning units
What type of pneumonia typically seen in patients with HIV?
Pneumocystic jiroveci
What are 3 features of pneumocystic jiroveci?
- Dry cough
- Exercise-induced desaturations
- Absence of chest signs
What is idiopathic interstitial pneumonia?
group of non-infective causes of pneumonia
What are is an example of an idiopathic interstitial pnuemnoa and what is it?
Cryptogenic organising pneumonia: form of bronchiolitis which may develop as a complication of rheumatoid arthritis or amiodarone therapy
What are 2 things that can cause cryptogenic organising pneumonia?
- Rheumatoid arthritis
- Amiodarone therapy
What is the source of the majority of causes of pneumonia?
Community-acquired pneumonia
Why is it important to distinguish between hospital and community acquired pneumonia?
different causative organisms and different first line antibiotic therapy
What are 5 symptoms of pneumonia?
- Cough
- Sputum
- Dyspnoea
- Chest pain: may be pleuritic
- Fever
What are 3 signs of pneumonia?
- Systemic inflammation response: fever, tachycardia
- Reduced oxygen saturations
- Auscultation: Reduced breath sounds, bronchial breathing
What are 3 important investigations in pneumonia?
- CXR
- Bloods: FBC, U+Es, CRP
- ABG
What will FBC show in pneumonia?
neutrophilia in bacterial infections
Why is it important to measure U+Es in pneumonia?
U (urea) for CURB65, and other changes seen with some atypical pneumonias
What are 2 situations when ABG is indicated for pneumonia?
low oxygen saturations or patient has pre-existing respiratory disease e.g. COPD
What is the broad management of pnuemonia?
antibiotics and supportive care e.g. oxygen, IV fluids
What does each part of CURB-65 represent?
- C: confusion (abbreviated mental test score 8 or less /10)
- U: urea >7mmol/L
- R: respiratory rate 30 or more
- B: blood pressure systolic <90 or diastolic <60
- 65: age 65 or over
What is the risk stratification process for pneumonia and what is it used to decide?
CURB65: where patient can be managed i.e. community or hospital
What does a CURB65 score of 0 indicate?
can manage in community
What does a CURB65 score of 1 indicate?
- need oxygen sats assessed, should be over 92 to be safely managed in community and CXR performed
- if CXR shows bilateral/ multilobar shadowing, hospital admission advised
What 2 investigations must be performed with a CURB65 score of 1?
- sats; if 92 or above can manage in community
- CXR: if bilteral or multilobar shadowing, manage in hospital
What does a CURB65 score of 2 or more indicate?
manage in hospital - represents severe CAP
What does the CURB65 score tell you about mortality?
patient with score of 4 approaching 30% mortality rate at 30 days
What are the 5 commonest causes of community-acquired pneumonia?
- Streptococcus pneumoniae (accounts for around 80% of cases)
- Haemophilus influenzae
- Staphlycoccus aureus
- Atypical pneumonias e.g. due to Mycoplasma pneumoniae
- Viruses
What criteria can be used in the primary care setting to determine whether someone with pneumonia can be managed in the community or not?
CRB65
- C: confusion; 8 or more on AMTS
- R: resp rate 30 or more
- B: blood pressure systolic <90 diastolic <60
- 65: age 65 or more
How can CRB-65 be used to classify patients for risk of death?
- 0: low risk (<1% mortality risk)
- 1-2: intermediate risk (1-10% mortality)
- 3-4: high risk (>10% mortality risk)
How can the result of the CRB65 be interpreted?
home-based care if score 0
hospital assessment for all other patients (especially 2 or more)
What test is recommended by NICE as a ‘point of care’ test in the primary care setting for pneumonia?
CRP - not widely available but recommended by NICE
How is CRP as a point of care test in primary care meant to be interpreted?
<20: don’t routeinly offer abx
20-100: consider delayed abx prescription
>100: offer abx therapy
Based on the CURB65 score when sould intensive care assessment be considered for patients?
score of 3 or more
In secondary care what are 5 investigations which may be performed?
- CXR
- intermediate or high risk: blood cultures
- intermediate or high risk: sputum cultulres
- intermediate or high risk: pneumococcal and legionella urinary antigen tests
- CRP monitoring to determine response to treatment
What is the management of low-severity community-acquired pneumonia?
- amoxicillin first line
- if penicllin allergic use macrolide or tetracycline
- 5 day course
What is the recommended management of moderate and high-severity community acquired pneumonia?
- dual antibiotic therapy with amoxicillin and macrolide (erythromycin or clindamycin)
- 7-10 day course
- consider beta-lactamase stable penicillin such as co-amoxiclav, ceftriaxone or piperacillin with tazobactam and macrolide in high severity community acquired pneumnoia
What are 7 reasons not to routinely discharge patients following pneumonia managed in hospital?
if 2 or more of the following in the past 24 hours:
- temperature higher than 37.5
- respiratory rate 24 or more
- heart rate over 100
- systolic BP <90
- sats <90% on room air
- abnormal mental status
- inability to eat without assistance
What do NICE recommend about temperature following pneumonia and discharge?
if temperture >37.5 they recommend delaying discharge
What are 5 points to advise patients on about the timescale of their recovery following pneumonia?
- 1 week: fever should resolve
- 4 weeks: chest pain and sputum production should have substantially reduced
- 6 weeks: cough and breathlessness should have substantially reduced
- 3 months: most symptoms should have resolved but fatigue may still be present
- 6 months: most poeple will feel back to normal
