Key facts:
Authors: Ruth de Souza and Ricky Jones
Top Tips: Rx different types of pneumonia very variable. Use CURB-65
Key Differential Diagnoses
- Pulmonary embolus
- Pleural effusion
- Pneumothorax
Key Investigations
- O2 saturation (± ABG)
- ECG, CXR
- FBC, CRP, U+E, LFT, Bone, Glucose
- BC, Sputum culture
- CURB-65 score
Key Treatment
- OXYGEN, if hypoxic, to achieve SpO2 95-97%
- PO AMOXICILLN 500 mg tds + PO ERYTHROMYCIN 500 mg qds (non severe CAP only); or other AB regimes
Note: Do NOT repeat failed regimens given in primary care
Key Management Decision
- Ventilation
Background
Introduction
- A CXR is needed to make a diagnosis (see definition). Pneumonia is acute inflammation of the lungs caused by infection. Initial diagnosis is based on the CXR
- Causes, symptoms, treatment, preventive measures, and prognosis differ markedly; depending on whether the infection is bacterial, viral, fungal, or parasitic; whether it is acquired in the community, hospital, or nursing home; and whether it develops in a patient who is immunocompetent or immunocompromised
- The aetiological agent cannot be reliably predicted from the clinical picture. Immunocompromised patients can present atypically - eg with SOB (and no CXR signs), or agitation, fever etc
- Look at the CXR properly, not only to confirm the diagnosis. It should also be used to: (1) delineate the extent of the consolidation; (2) indicate the presence of underlying disorders eg carcinoma; and (3) denote the presence of complications
- Mortality is 10% in CAP (community-acquired pneumonia); 20% in healthcare–associated pneumonia (HCAP), and hospital-acquired pneumonia (HAP); and 30% in ventilator-associated pneumonia (VAP): [Ref]
Definition
- LRTI associated with fresh radiological shadowing on CXR
Epidemiology
- Incidence 1-3/1000 pa
Classification
- Anatomical: Lobar or Bronchopneumonia
- Origin: Community-acquired (CAP), Hospital-acquired (HAP), Aspiration or Opportunistic
- Microbiological
Risk factors
- Age, alcohol, smoking, HIV/immunosuppression, dementia
Causes
- Bronchial obstruction, secondary to foreign body or carcinoma
- Chronic lung disease (Bronchiectasis; asthma/COPD; pulmonary fibrosis, especially cystic fibrosis)
- Achalasia
- Co-existing chronic disease (eg failures)
Note: patients with R sided endocarditis can present with haemoptysis, fever, consolidation ± cavitation
Common organsisms
- Streptococcus pneumoniae (>30%)
- Mycoplasma pneumoniae
- Haemophilus influenzae
- Viruses (15%)
- Many other organisms
NB: 'rare organisms' (eg CMV, PCP and TB) are common in at risk groups (eg HIV and immunosuppressed)
Symptoms
- Of LRTI
- Haemoptysis
- Chest pain, often pleuritic (can be of rapid onset, especially streptococcus pneumoniae)
- Diarrhoea (legionella)
NB: in previously normal lungs, most types of pneumonia will not usually (on their own) cause SOB; ie if SOB, think another cause (eg PE); or pneumonia plus something else; or an early opportunistic pneumonia (eg CMV, PCP)
Key questions
- "When did your symptoms start?"
- "Do you have any other longterm lung disease, or other chronic diseases?"
Signs
- Fever, pleural rub (listen over site of maximal pain)
- Of consolidation
- Of complication (eg pleural effusion)
- Of severe sepsis (SOB, tachycardia, drowsiness)
Investigation
Blood
- FBC (haemolysis think mycoplasma), CRP
- U+E, LFTs, Bone, Glucose, CK (makes legionella more likely)
Note: if ARF, think of pulmonary-renal syndrome (dont necessarily have haemoptysis) - ABG
Note: significant hypoxia can lead to minimal changes in vital signs, in fit people - Blood culture
- Serology (for atypical organisms eg legionella, mycoplasma)
Other
- Urinary dipstick
- Urine for legionella and pneumococcal antigens
- Sputum culture, urgent microscopy with gram stain
- ECG
- CXR
Note: need fresh XR changes to make the diagnosis; comparing old and new XRs can be helpful
Lobar pneumonia - Right upper lobe
Right middle lobe pneumonia
Lobar pneumonia - Right lower lobe
CXR - bronchopneumonia (usually more serious than lobar)
CXR - Opportunistic (PCP/PCJ in this case); can be normal initially, all very serious)
Key investigations
- CXR
- ABG, if unwell
Specialist investigations
- Blood: ZN stain, sputum for AFBs; atypical organisms (mycoplasma pneumoniae,legionella, chlamydia psittaci, influenza A + B)
- Urine: Legionella
- Pleural fluid aspiration/bronchoalveolar lavage (to isolate organism)
- CT chest (carcinoma or possible empyema?)
- Bronchoscopy (if suspect foreign body or carcinoma)
Differential diagnoses
- Pulmonary embolus
- Pleural effusion
- Pneumothorax
- Pulmonary neoplasm
- Pulmonary haemorrhage (?part of Pulmonary-Renal Syndrome, eg Goodpasture's; v rare)
- Simple LRTI (normal CXR)
- Lung abscess
- (Unilateral) pulmonary oedema
Treatment
Some well patients with pneumonia can be managed as an outpatient
Treatment
Drugs
- CAP (community-acquired, non-severe)
- PO AMOXICILLN 500 mg tds + PO ERYTHROMYCIN 500 mg qds (Penicillin Allergy: PO ERYTHROMYCIN 500 mg qds)
Note: If atypical pathogen suspected, refer to respiratory physician for advice
- PO AMOXICILLN 500 mg tds + PO ERYTHROMYCIN 500 mg qds (Penicillin Allergy: PO ERYTHROMYCIN 500 mg qds)
- CAP (community-acquired, severe)
- IV CO-AMOXICLAV 1.2g tds + IV ERYTHROMYCIN 500 mg qds (Penicillin Allergy: IV ERTAPENEM 1g od + IV ERYTHROMYCIN 500 mg qds)
Notes: change to oral after 48hrs if patient improving; some infections (eg Legionella) may require 10-14 days treatment; IV macrolides require central line, or large bore IV cannula
- IV CO-AMOXICLAV 1.2g tds + IV ERYTHROMYCIN 500 mg qds (Penicillin Allergy: IV ERTAPENEM 1g od + IV ERYTHROMYCIN 500 mg qds)
- (Community-Acquired) Aspiration Pneumonia
- IV CO-AMOXICLAV 1.2 g tds (Penicillin Allergy: IV ERTAPENEM 1 g od)
- Hospital-Acquired Pneumonia (HAP)/No antibiotics since admission
- IV CO-AMOXICLAV 1.2 g tds + IV GENTAMICIN 5 mg/kg od (Penicilin Allergy: IV MEROPENEM 1 g tds + IV GENTAMICIN 5 mg/kg od)
- HAP/Received antibiotics since admission
- IV TAZOCIN 4.5 g tds + IV GENTAMICIN 5 mg/kg od (Penicillin Allergy: IV MEROPENEM 1 g tds + IV GENTAMICIN 5 mg/kg od)
Note: atypical, opportunistic or neutropenic patients may require different antibiotics (DW microbiology)
- IV TAZOCIN 4.5 g tds + IV GENTAMICIN 5 mg/kg od (Penicillin Allergy: IV MEROPENEM 1 g tds + IV GENTAMICIN 5 mg/kg od)
Procedures
- PO PARACETAMOL 1 g qds, if pain
- IV line (and fluids; almost always dry)
- OXYGEN, if hypoxic; % according to needs (± COPD) initially, via Venturi Mask; to keep SpO2 95-97%
[Ref]
Key management decisions
- Ventilate/not
- ITU/not
Stop/reduce
- Immunosuppression (DW prescriber)
Treatment (second line)
Drugs
- For septic shock (inotropes etc)
- Non-standard antibiotics (if suspect opportunistic organism); eg cotrimoxazole (for PCP), TB Rx, antiviral and antifungal agents (after DW microbiology)
Procedures
- Urinary catheter, CVP line, arterial line
Prescribing issues
- AB therapy should be orientated to the type of pneumonia
Admit?
- Usually; but, if well, CURB-65 0-1, and good home support, can be handled as OP - with appropriate follow-up
Bed plan
- Medical admission ward
- ± Respiratory
- ± ITU
Referrals
Medical
- Senior if CURB ≥ 2
- ± ITU, if CURB 65 ≥ 3
- ± Respiratory (if diagnosis unclear, or suspect underlying cause)
- ± MB/Infectious diseases (if diagnosis unclear and/or unusual organisms)
Other
- Respiratory nurse (especially if underlying COPD)
The Rest
Use the CURB-65 score, its very simple and helpful as a management guide
Maxim
- 'Who ever died of pneumonia?'
Complications
- Parapneumonic effusion, empyema, lung abscess or systemic dissemination
Follow-up
- GP
- Respiratory, if disease/organism unusual, or suspect underlying carcimona
Note: recheck CXR in > 6 wks, if suspect underlying Ca (radiological signs should have cleared by then)
Prognosis
- Mortality is 10% in CAP (community-acquired pneumonia); 20% in healthcare–associated pneumonia (HCAP), and hospital-acquired pneumonia (HAP); and 30% in ventilator-associated pneumonia (VAP)
- ie, Death more common in elderly, from nursing home, septicaemic, ITU
Score
- CURB 65 (acronym for each of risk factors measured, each scoring one point, maximum score = 5); it was developed to combat the problem of not taking this disease seriously, especially in >75 yrs, where mortality can be much higher than 10%; it may require aggressive therapy
1. confusion (defined as an AMT of 8 or less)
2. urea > 7 mmol/l
3. respiratory rate > 30
4. blood pressure <90 systolic or <60 diastolic
5. age 65 or older
Risk stratification (who can be managed as outpatient)
- If well, CURB-65 0-1, and good home support, can be handled as OP - with appropriate follow-up. There are more complicated systems: [Ref]
2° Prevention + Health Promotion
- Stop smoking/alcohol
- Reduce/stop immunosuppresion (after DW prescriber)
- Pneumococcal vaccine (at risk groups eg >65; DM, CRF, CCF, CLF, COPD, immunosuppressed)
Don't forget
- Recheck CXR in > 6 wks, if suspect underlying Ca
- If not getting better at 48h, DW microbiology, and ?change antibiotics
- TB
Red flags
- CURB 65 ≥ 2, ask for senior review; ≥ 3 ask for ITU opinion