1. Investigations within 24 hours of admission should include FBC, BUSE, ECG, culture of sputum (if sputum is purulent), blood culture (if pneumonia is suspected), CXR, ABG, and serial peak flow chart started (in patients who could still use peak flow meter) as soon as possible.
2. Oxygen:
• Should be administered to maintain a PaO2 of 55-60mm Hg (88-90%
saturation) without a fall in pH (secondary to a rise in PaCO2). It can be given by nasal canula 1-2L/min or 24-28% oxygen by mask. Higher levels of O2 may result in PaCO2 elevation, with consequent depression of mental status, hypoventilation, and further impairment of gas exchange.
• Check ABG within 60 mins of starting O2 or change of O2 concentration. If PaO2 improves with no or minimal deterioration in pH, then the inspiratory concentration can be increased and the blood gas tensions rechecked.
• If the PH falls or PCO2 rises, consider alternative strategies eg IPPV, NIPPV, if the chance of weaning off is good, ie NOT endstage COPD.
3. Nebulized bronchodilators:
• ß2-adrenergic agonists (salbutamol 2.5-5mg or terbutaline 5-10mg) with or without anticholinergic agents (ipratropium bromide 0.25-0.5mg) should be given on arrival and at 4-6 hourly internals thereafter but may be used more frequently if required.
• Nebulizer should be driven by compressed air rather than O2.
• Oxygen can continue to be given by nasal prongs at 1-2L/min during nebulisation in order to prevent the fall in oxygen saturation.
4. Aminophylline:
• Administration should be considered in patients who respond poorly to nebulized bronchodilators.
• Bolus dose: Aminophylline intravenous 250 mg over 20 minutes ( do not give bolus aminophylline to patients already taking oral theophyllines) followed by infusion (mix 250mg or 500mg in 500ml of NS or D5%) at a rate of 0.5-0.9mg/kg/hour; 0.5mg/kg/hour for non smoker, 0.8-0.9mg/kg/hour for smoker, 0.3mg/kg for older patient, 0.1-0.3mg/kg/hour for patient with heart failure, cirrhosis or on cimetidine, ciprofloxacin or erythromycin.
• Monitor blood levels if aminophylline infusion is continued for more than 24 hours (therapeutic levels 10-20mcg/ml or 55-110umol/l).
5. Corticosteroids:
• IV or oral corticosteroids may be useful if:
- there is previously documented response to oral corticosteroids.
- the airflow obstruction fails to respond to an increase in bronchodilators dosage.
- this is the first presentation of airways obstruction.
• Corticosteroids can be given as prednisolone 30mg/day or IV 200mg hydrocortisone if the oral route is not possible for 7-14 days.
• A 'trial' of oral corticosteroids (usually 30-40mg/day for 2-3 weeks) can be done, if not already, to determine the need for long term inhaled corticosteroids. As a rule of thumb, patients who show a 20%improvement in PEFR or FEV1 (mean of last 3 days readings) over baseline (mean of first 3 days readings) in a trial can be considered for maintenance inhaled corticosteroid treatment.
6. Antibiotics :
• Antibiotics should be given if two or more of the three features described below are present:
i. Increased breathlessness.
ii. Increased sputum volume.
iii. Development of purulent sputum.
• All patients with acute on chronic respiratory failure (PH<7.35) should also receive antibiotics.
• Common antibiotics will usually be adequate but the antibiotics used should have activities against Strep pneumoniae, H influenzae & Moraxella catarrhalis; amoxycillin or doxycycline are first choice unless used with poor response prior to admission.
• For more severe exacerbations, or if there is lack of response to the above agents, several second line alternatives can be considered eg. 2nd or 3rd generation cephalosporin, amoxicllin-clavulanate, ciprofloxacin or the newer macrolides (eg. clarithromycin or azithromycin).
7. Chest physiotherapy - may be beneficial to improve clearance of secretions.
8. Hydration and diuretics - COPD patients are sensitive to changes in fluid status, and intravenous rehydration is almost always necessary unless there is clinically evident of cor pulmonale with peripheral oedema when fluid replacement ought to be under taken more cautiously.
9. Mechanical ventilation may be considered in patients with acute ventilatory failure. Mechanical ventilation is withheld in endstage disease, when permanent ventilator dependence is likely. In general, the following factors can be used to guide the decision for ventilation:
a. Factors to encourage use of IPPV:
• A demonstrable remedial reason for current decline - for example, radiographic evidence of pneumonia or drug overdosage.
• The first episode of respiratory failure.
• An acceptable quality of life or habitual level of activity prior to exacerbation.
b. Factors likely to discourage use of IPPV:
• Previously documented severe COPD that has been fully assessed and found to be unresponsive to relevant therapy.
• A poor quality of life - for example, being housebound, in spite of maximal appropriate therapy.
• Severe co-morbidities - for example bronchogenic neoplasia.
10. Monitoring and management as the patient recovers:
• FEV1 should be measured prior to discharge in centres where spirometry is available.
• Nebulized bronchodilators should be continued until the patient is improving clinically. Bronchodilators can then be given by metered dose aerosol or dry powder inhalers, ideally at least 24-48 hours before discharge.
• If corticosteroids have been used they can usually be stopped abruptly after seven days unless there are positive reasons for long term usage.
• Before discharge, the following should be done:
• A review of all medications.
• Check inhaler technique.
• Ensuring that the patient knows how and when to take his/her medication.
PNEUMONIA
Classification of pneumonia 1. Community acquired pneumonia.
(a) Primary pneumonia in healthy adult.
(b) Secondary pneumonia in patient with debility eg COPD.
2. Hospital acquired (Nosocomial) pneumonia.
3. Aspiration pneumonia.
4. Pneumonia in the immunocompromised host.
Important causes of community acquired pneumonia
a. Healthy adult.
* Present as Atypical pneumonia.
b. Patient with debility.
1. Streptococcus pneumoniae.
2. Respiratory viruses.
3. Haemophilus influenzae.
4. Moraxella catarrhalis.
5. Klebsiella pneumoniae.
6. Enteric gram negatives.
7. Staph aureus.
8. Mycobacteria.
Important causes of hospital acquired pneumonia
1. Gram negative bacteria (esp. Klebsiella sp & Pseudomonas aeruginosa, Enterobacter sp, E coli, Proteus, Serratia).
2. Staphylococcus aureus.
3. Anaerobes.
4. Streptococcus pneumoniae.
5. H. influenza.
Important causes of pneumonia in the immunocompromised host 1. Pneumocystis carinii.
2. Mycobacteria.
3. Viruses (eg.Cytomegalovirus, Herpes simplex).
4. Fungi (Candida, Aspergillus, Cryptococcus).
5. Strongyloides stercoralis.
6. Enteric gram negatives.
7. Enteric anaerobes.
A Clinical Features
• Traditionally divided into 2 clinical patterns:
a. ”Typical” pneumonia - characterized by a sudden onset of illness with high fever, sweats, rigors, pleuritic chest pain, cough, sputum production, haemoptysis, dyspnoea, tachypnoea, tachycardia, pleural rub, rhonchi and signs of consolidation and a ‘toxic’ appearance. Chest X-ray shows a lobar or lobular opacity. White cell count is usually markedly elevated.
b. ”Atypical” pneumonia- characterized by a gradual onset of non-productive cough, dyspnoea, constitutional symptoms and low grade fever. Clinical findings are often minimal. White cell count is often not elevated. Chest X-ray characteristically show a diffuse bilateral pulmonary infiltrate which appears worse than accounted for by the clinical signs.
B. Investigations
1. General: FBC, BUSE, CXR, LFT, se creatinine, ABG, cold agglutinins (if mycoplasma suspected), etc.
2. Microbiology diagnosis:
• Sputum culture and microscopy.
• Blood culture.
• Acid fast bacilli.
• Pleural aspiration for analysis and cultures if effusion is present.
• Bronchoscopy should be considered in solitary lung abscess.
• Serology (or serum antibody titres) for mycoplasma, chlamydia, legionella or viruses when atypical pneumonia is suspected. A rising titre over a 2 week interval may provide a retrospective diagnosis. Persistently high antibody titre can also be suggestive.
• Immunofluorescence or Giemsa stain for pneumocystis carinii from
• If the patient is very ill or has not responded to conventional treatment, the correctness of the diagnosis or the aetiological agent and the possibility of an occult underlying bronchogenic malignancy must be suspected. In such a case the following tests may be done:
i) Bronchoalveolar lavage.
ii) Percutaneous lung aspiration.
iii) Lung biopsy (transbronchial/open lung biopsy).
Indications for hospitalization for community acquired pneumonia
• Age >60.
• Coexisting illnesses eg alcoholism, DM, COPD, LVF.
• Alteration in vital signs eg hypotension.
• Leukopenia or marked leukocytosis.
• Any evidence of respiratory failure.
• Alteration in mental status eg. confusion
• CXR shows multilobar involvement
• Urea > 7 mmol/L
• Septic appearance.
• Absence of supportive care at home.
C. Management