Respiratory
Question 116 of 180
A 1 year old girl is brought to the Emergency Department by her parents. She has been coughing for 3 days and been off her food. She is febrile and on auscultation you note coarse left basal crepitations. You suspect a diagnosis of pneumonia. What is the most likely causative organism?
Answer:
Viruses account for most cases of community acquired pneumonia (CAP) during the first two years of life. After this period, bacterial pneumonia become more frequent. Streptococcus pneumoniae is the most common bacterial cause. Note that all children with a clear clinical diagnosis of community acquired pneumonia should receive antibiotics as bacterial and viral pneumonia cannot reliably be distinguished from each other.Paediatric Pneumonia
Respiratory
Last Updated: 12th February 2021
Community-acquired pneumonia is an acute infection of the lung parenchyma, that may be caused by bacterial or viral infection. Infection leads to localised collapse and consolidation of the alveolar air spaces, resulting in impaired gas exchange, which may cause hypoxia and breathlessness.
Causes
Viruses account for most cases of community acquired pneumonia (CAP) during the first two years of life. After this period, bacterial pneumonia become more frequent.
- Bacterial
- Streptococcus pneumoniae (most common)
- Staphylococcus aureus
- Haemophilus influenzae
- Mycoplasma pneumoniae
- Chlamydia pneumoniae
- Viral
- Respiratory syncytial virus (RSV) (most common)
- Parainfluenza virus
- Influenza virus
- Neonates
- Listeria monocytogenes
- Escherichia coli
- Klebsiella pneumoniae
Diagnosis
Pneumonia should be considered if the child has:
- A high fever (over 39°C) and/or
- Cyanosis.
- Raised respiratory rate (greater than 60 breaths per minute, age 0–5 months; greater than 50 breaths per minute, age 6–12 months; greater than 40 breaths per minute, age older than 12 months).
- Signs of increased work of breathing, such as chest indrawing and nasal flaring.
- Persistently focal crackles.
- Cyanosis.
- Oxygen saturation of 95% or less in air.
- Absent breath sounds with a dull percussion note (possibility of pneumonia complicated by an effusion).
Differential diagnosis of acute cough with chest signs in children
| Pneumonia | Bronchiolitis | Viral-induced wheeze | Infective exacerbation of asthma | |
|---|---|---|---|---|
| Age | Any age | Under 2 years | Under 5 years | Any age |
| Respiratory rate | Usually increased | Usually increased | May be normal or increased | May be normal or increased |
| Hyperinflation | Not present | Often present | May be present | May be present |
| Wheeze | Not usually present | May be present | Present | Present |
| Crackles | Coarse, crackles, usually focal | Fine crackles throughout lung fields | Not usually present | Not usually present |
Investigations
- CXR should not be performed routinely in children with suspected community acquired pneumonia (CAP); children with suspected pneumonia who are not admitted to hospital should not have a chest x-ray.
- Acute phase reactants (including CRP) are not of clinical utility in distinguishing viral from bacterial infections and should not be tested routinely.
- Microbiological investigations should not be considered routinely in those with milder disease or those treated in the community.
- Microbiological diagnosis should be attempted in children with severe pneumonia sufficient to require paediatric intensive care admission or those with complications of CAP.
- Blood culture
- Nasopharyngeal secretions and/or nasal swabs for viral detection by PCR and/or immunofluorescence
- Acute and convalescent serology for respiratory viruses, Mycoplasma and Chlamydia
- If present, pleural fluid should be sent for microscopy, culture, pneumococcal antigen detection and/or PCR
Management
- If appropriate, children should be managed at home and parents given advice about management of fever, hydration and identifying deterioration.
- Give controlled oxygen supplementation to children if their oxygen saturation is equal or less than 92%, to maintain saturations > 92% when breathing air.
- Plasma sodium, potassium and renal function should be measured at baseline and at least daily when on intravenous fluids.
- Chest physiotherapy is not useful and should not be performed in children with pneumonia.
- All children with a clear clinical diagnosis of community acquired pneumonia should receive antibiotics as bacterial and viral pneumonia cannot reliably be distinguished from each other.
- Start antibiotic treatment as soon as possible after establishing a diagnosis of community-acquired pneumonia, and certainly within 4 hours (within 1 hour if the person has suspected sepsis and meets any of the high risk criteria for this.
- Give oral antibiotics first line if the person can take oral medicines, and the severity of their condition does not require intravenous antibiotics.
- If intravenous antibiotics are given, review by 48 hours and consider switching to oral antibiotics if possible.
| Patient group | Antibiotic |
|---|---|
| Children under 1 month |
|
| Child 1 month - 18 years with non-severe pneumonia |
|
| Child 1 month - 18 years with severe pneumonia |
|
Complications
- Septicaemia
- Pleural effusion
- Empyema
- Lung abscess
- Respiratory failure, hypoxia and death
Report A Problem
Is there something wrong with this question? Let us know and we’ll fix it as soon as possible.
Loading Form...
- Biochemistry
- Blood Gases
- Haematology
| Biochemistry | Normal Value |
|---|---|
| Sodium | 135 – 145 mmol/l |
| Potassium | 3.0 – 4.5 mmol/l |
| Urea | 2.5 – 7.5 mmol/l |
| Glucose | 3.5 – 5.0 mmol/l |
| Creatinine | 35 – 135 μmol/l |
| Alanine Aminotransferase (ALT) | 5 – 35 U/l |
| Gamma-glutamyl Transferase (GGT) | < 65 U/l |
| Alkaline Phosphatase (ALP) | 30 – 135 U/l |
| Aspartate Aminotransferase (AST) | < 40 U/l |
| Total Protein | 60 – 80 g/l |
| Albumin | 35 – 50 g/l |
| Globulin | 2.4 – 3.5 g/dl |
| Amylase | < 70 U/l |
| Total Bilirubin | 3 – 17 μmol/l |
| Calcium | 2.1 – 2.5 mmol/l |
| Chloride | 95 – 105 mmol/l |
| Phosphate | 0.8 – 1.4 mmol/l |
| Haematology | Normal Value |
|---|---|
| Haemoglobin | 11.5 – 16.6 g/dl |
| White Blood Cells | 4.0 – 11.0 x 109/l |
| Platelets | 150 – 450 x 109/l |
| MCV | 80 – 96 fl |
| MCHC | 32 – 36 g/dl |
| Neutrophils | 2.0 – 7.5 x 109/l |
| Lymphocytes | 1.5 – 4.0 x 109/l |
| Monocytes | 0.3 – 1.0 x 109/l |
| Eosinophils | 0.1 – 0.5 x 109/l |
| Basophils | < 0.2 x 109/l |
| Reticulocytes | < 2% |
| Haematocrit | 0.35 – 0.49 |
| Red Cell Distribution Width | 11 – 15% |
| Blood Gases | Normal Value |
|---|---|
| pH | 7.35 – 7.45 |
| pO2 | 11 – 14 kPa |
| pCO2 | 4.5 – 6.0 kPa |
| Base Excess | -2 – +2 mmol/l |
| Bicarbonate | 24 – 30 mmol/l |
| Lactate | < 2 mmol/l |
