Respiratory Tract Infection

Respiratory tract infections (RTIs) can be caused by a variety of microorganisms, including bacteria, viruses, and, less commonly, fungi.

Here’s a breakdown of some common RTIs, their typical causative organisms, and general treatment recommendations:

Upper Respiratory Tract Infections (URTIs)

  1. Nasopharyngitis (Common Cold):
    1. Causes: Rhinoviruses, coronaviruses, adenoviruses, etc.
    2. Management:
      1. Symptomatic treatment with rest, hydration and over-the-counter (OTC) pain relievers like paracetamol or ibuprofen.
      2. Decongestants can help with nasal congestion.
      3. Antiviral or antibiotic treatment is not necessary.
  2. Pharyngitis (Sore Throat):
    1. Causes: Adenoviruses, rhinoviruses, Epstein-Barr virus; bacterial causes include Streptococcus pyogenes (Group A Strep)
    2. Management:
      1. Analgesics like paracetamol or ibuprofen for pain and fever.
      2. If bacterial (strep throat) penicillin may be indicated.
  3. Tonsillitis:
    1. Causes: Similar to pharyngitis.
    2. Management:
      1. Analgesics for pain and fever.
      2. If bacterial, penicillin may be indicated.
      3. Severe or recurrent cases might require tonsillectomy, but we need 7-5-3 infections
        1. 7 infections in one year
        2. 5 infections per year for 2 years
        3. 3 infections per year for 3 years
  4. Laryngitis:
    1. Causes: Mostly viral, like influenza and parainfluenza.
    2. Management:
      1. Voice rest, hydration, humidification, and analgesics.
      2. Antiviral or antibiotic treatment is usually not required.
  5. Sinusitis (Rhinosinusitis):
    1. Causes: Common cold viruses; bacterial causes include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
    2. Management:
      1. Saline nasal irrigation, decongestants, analgesics for pain and fever.
      2. If bacterial and symptoms are severe or prolonged, antibiotics like amoxicillin, cefuroxine or doxycycline may be prescribed.
  6. Epiglottitis:
    1. Causes: Haemophilus influenzae type b (less common now due to vaccination).
    2. Management:
      1. This is a medical emergency.
      2. DO NOT LOOK IN THE THROAT
      3. Patients may require intubation or tracheostomy to maintain an open airway.
      4. Intravenous antibiotics are initiated.
  7. Croup (Laryngotracheobronchitis):
    1. Causes: Parainfluenza virus (usually) or RSV
    2. Management:
      1. Mild cases can be managed with cool, moist air (e.g., from a humidifier) and calming the child.
      2. More severe cases might require a single dose of oral corticosteroids (ie Prednisolone 1mg/kg)
      3. In emergency settings, nebulized adrenaline may be used.
  8. Pertusis (Whooping Cough)
    1. Cause: Bordatella pertusis
    2. Management:
      1. Azithromycin 10mg/kg oral up to 500mg on day 1, then 5mg/kg up to 250mg on days 2-5.
        • Same regimen is use for prophylaxis in contacts
        • No point using ABX after 21 days cough because non infectious at this stage and can return to day care/school
      2. Can return to school after 5/7 Rx
      3. Vacination is key to prevention
  9. Tracheitis:
    1. Causes: Bacterial, with Staphylococcus aureus being common.
    2. Management:
      1. Hospitalization with intravenous antibiotics.
      2. Sometimes intubation is required to secure the airway.

General Points:

  • Viral URTIs do not benefit from antibiotic treatment, and their use in these cases can promote antibiotic resistance and unnecessary side effects.
  • It’s important to differentiate between viral and bacterial causes where possible to guide treatment.
  • Individuals with underlying health conditions or compromised immune systems may require more aggressive or specialized management.

Lower Respiratory Tract Infections (LRTIs)

  1. Bronchitis:
    1. Causes: Mostly viral, including influenza, parainfluenza, rhinoviruses, and RSV.
    2. Management:
      1. Usually supportive, including rest, hydration, and over-the-counter analgesics.
      2. Cough suppressants might help.
      3. Antibiotics are not typically needed unless there’s suspicion of a secondary bacterial infection.
  2. Bronchiolitis:
    1. Causes: RSV, especially in infants; also human metapneumovirus and rhinoviruses.
    2. Management:
      1. Supportive care, including hydration and monitoring for breathing difficulties.
      2. Hospitalization may be required for severe cases.
      3. Bronchodilators and corticosteroids are sometimes used, though evidence for their routine use is limited.
  3. Pneumonia:
    1. Causes:
      1. Viral: Influenza, RSV, adenoviruses, human metapneumovirus, SARS-CoV-2.
      2. Bacterial: Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae, Legionella pneumophila.
    2. Management:
      1. Depends on the causative agent.
      2. Bacterial pneumonia often requires antibiotics, e.g., amoxicillin 1g TDS and/or doxycycline 100mg BD depending on the suspected bacteria and local resistance patterns.
      3. Viral pneumonia management is supportive, though antiviral medications might be used for specific viruses like influenza and SARS-CoV-2
  4. Tuberculosis (TB):
    1. Causes: Mycobacterium tuberculosis.
    2. Management:
      1. Long-term treatment with anti-TB drugs such as rifampicin, isoniazid, pyrazinamide, and ethambutol (RIPE)
      2. TB is a serious infection and requires close monitoring by a healthcare provider.
  5. Pleural Effusion/Empyema:
    1. Causes: Can be secondary to bacterial infections like TB or pneumonia.
    2. Management:
      1. Treatment of the underlying cause.
      2. Therapeutic thoracentesis might be needed to remove fluid from the pleural space and for cytology and M,C&S
  6. Lung Abscess:
    1. Causes: Anaerobes like Bacteroides, Peptostreptococcus, Fusobacterium; aerobes like Staphylococcus aureus or Klebsiella pneumoniae.
    2. Management:
      1. Antibiotics that cover anaerobes and potential aerobes.
      2. Surgical intervention or percutaneous drainage might be necessary in some cases.
  7. Respiratory Syncytial Virus (RSV) Infection:
    1. Management: Supportive care, hydration, and monitoring for breathing difficulties. Severe cases might require hospitalization.
  8. Pneumocystis Pneumonia (PCP):
    1. Causes: Pneumocystis jirovecii, often in immunocompromised individuals ie HIV/AIDS
    2. Management:
      1. Treatment typically includes the combination of trimethoprim-sulfamethoxazole (TMP-SMX).
      2. Adjunctive corticosteroids may be beneficial in cases with significant hypoxia.
  9. Aspiration Pneumonia:
    1. Causes: Inhalation of oropharyngeal or gastric contents leading to infection by anaerobes and aerobes.
    2. Management: Antibiotics that cover anaerobes and typical aerobes, such as amoxicillin-clavulanate or clindamycin.
  10. Legionnaires’ Disease:
    1. Causes: Legionella pneumophila.
    2. Management: Antibiotics such as azithromycin or doxycycline.

General Points:

  1. The precise management might vary based on the severity of the disease, the presence of underlying health conditions, local antimicrobial resistance patterns, and updated clinical guidelines.
  2. Always consider the risk of complications, and hospitalization might be necessary for severe LRTIs or those at risk for rapid deterioration.
  3. Patients should always be advised to seek medical care if they suspect they have an LRTI, especially if experiencing severe symptoms or if they belong to high-risk groups (e.g., the elderly, immunocompromised, very young).
  4. Preventative measures, such as vaccination for influenza and pneumococcal pneumonia, can help reduce the incidence of some LRTIs.

Pneumonia can be caused by a variety of microorganisms, including bacteria, viruses, and fungi. The most common causative organisms often depend on the setting (community-acquired vs. hospital-acquired), age of the patient, and presence of underlying health conditions.

Community-Acquired Pneumonia (CAP)

  1. Bacteria:
    1. Streptococcus pneumoniae (pneumococcus): The most common cause of bacterial CAP in adults.
    2. Haemophilus influenzae: Especially in individuals with chronic lung disease.
    3. Mycoplasma pneumoniae: Often affects younger adults.
    4. Chlamydophila pneumoniae: Another cause of “atypical” pneumonia.
    5. Legionella pneumophila: Can cause outbreaks, especially after exposure to contaminated water systems.
  2. Viruses:
    1. Influenza virus: Especially common during the flu season.
    2. Respiratory syncytial virus (RSV): Common in infants and older adults.
    3. Other viruses: parainfluenza, coronavirus (including SARS-CoV-2, the cause of COVID-19), adenovirus, and human metapneumovirus.

Hospital-Acquired Pneumonia (HAP) and Ventilator-Associated Pneumonia (VAP)

  1. Bacteria:
    • Pseudomonas aeruginosa
    • Staphylococcus aureus: Methicillin-resistant Staphylococcus aureus (MRSA) is of particular concern.
    • Klebsiella pneumoniae
    • Escherichia coli
    • Other Enterobacteriaceae.

Pneumonia in Immunocompromised Hosts:

  1. Fungi:
    1. Pneumocystis jirovecii (previously Pneumocystis carinii)
      1. Common in people with HIV/AIDS.
    2. Cryptococcus neoformans
    3. Aspergillus spp.
  2. Viruses:
    1. Cytomegalovirus (CMV)
    2. Herpes simplex virus (HSV)
  3. Bacteria:
    1. Nocardia
    2. Mycobacterium avium complex (MAC)

Pneumonia in Children:

  1. Viruses:
    1. RSV
    2. Human metapneumovirus
    3. Rhinovirus
    4. Influenza virus
  2. Bacteria:
    1. Streptococcus pneumoniae
    2. Haemophilus influenzae type b (Hib): Much less common now due to vaccinations.
    3. Mycoplasma pneumoniae: More common in school-aged children.
  3. Fungi:
    1. Rare but can include Histoplasma in endemic areas.

Respiratory Distress in Children

One of the most common reasons an infant is admitted to the neonatal intensive care unit is due to Respiratory distress. Respiratory distress can be recognised as one or more signs of increased work of breathing, which will be discussed below.

The ability to identify signs of respiratory distress in children is important for people working in pediatric healthcare, as well as for parents and caregivers. Respiratory distress can manifest through a spectrum of signs, ranging from subtle cues to more obvious symptoms. The early identification of these signs and symptoms plays an important role in ensuring timely intervention, which can be critical in preventing further complications.

Signs and Symptoms

Below are the more common signs and symptoms and their causes:

  • Weak cry
    • This sign of fatigue and shows the child is prioritising energy expenditure for work of breathing.
  • Grunting
    • Grunting is an increased positive and expiratory pressure (PEEP) by closing the glottis (therefore increasing Functional Residual Capacity (FRC).
  • Tachypnea
    • Tachypnea is a medical term for an abnormally rapid breathing rate where this rate is more than considered typical for their age group.
    • Tachypnea occurs when the infant is unable to increase tidal volume, thus leading to an increase in respiratory rate.
    • The breathing rate in typically healthy children undergoes significant changes during the initial year of life. It decreases from an average of around 50 breaths per minute in full-term newborns to about 40 breaths per minute at 6 months of age and 30 breaths per minute at 12 months.
    • If tachypnea is present, it means that the respiratory rate exceeds 60 breaths per minute in infants aged 0-2 months, >50 breaths in infants 2-12 months, >40 in children 1-5 years and >20 in children above 5 years.
Age GroupNormal Respiratory Rate (breaths per minute)
Newborns (0-1 month)30-60
Infants (1 month – 1 year)30-50
Toddlers (1-3 years)24-40
Preschoolers (3-5 years)22-34
School-age Children (6-12 years)18-30
Adolescents (13-18 years)12-20
Adults12-20
  • Cricoid Tug/Tracheal tug
    • As the diaphragm contracts more forcefully to draw in air, it exerts a downward pull on the trachea, resulting in a visible tug.
  • Sternal recession
    • Sternal recession occurs when the space between the ribs and the sternum moves more inward than usual during breathing. This inward movement happens as the body exerts extra effort to draw air into the lungs.
    • This phenomenon is a response to high negative pressures during inspiration.
  • Sub-costal and intercostal recession
    • Sub-costal and intercostal refer to observable signs of respiratory distress in which the soft tissues in the areas beneath and between the ribs exhibit inward movement during the breathing process. These recessions in the soft tissues occur when the respiratory muscles must work harder than usual to draw air in.
    • This heightened effort is a response to high negative pressures experienced during inspiration.
  • Nasal flaring
    • Nasal flaring is an indication of respiratory distress characterized by the widening of the nostrils during breathing. This occurs as the body responds to the increased demand for air, attempting to reduce airflow resistance in the nasal passages.
    • The dilation of the nostrils allows for more air intake, facilitating a more efficient exchange of oxygen and carbon dioxide.
  • Head bopping
    • This behaviour, characterized by repetitive up-and-down movements of the head, is attributed to the increased use of sternocleidomastoid and scalene muscles.
    • Head bopping serves as a signal that the infant is experiencing breathing difficulties.
  • Clammy
    • The skin can feel cool, moist, and slightly sticky to the touch.
    • This is a physiological response from the body to attempt to regulate the temperature during increased respiratory effort.
    • When an infant is experiencing respiratory distress, they may expend considerable energy and effort in breathing. This can lead to increased sweating as the body works to maintain an optimal temperature.
  • Pallor
    • Pallor refers to a pale or whitish skin tone and can indicate reduced oxygen levels in the blood. Pallor is particularly noticeable around the lips and face.
  • Cyanosis
    • Cyanosis is a bluish discolouration of the skin and mucous membranes, typically noticeable around the lips, face, and extremities.
    • In the context of respiratory distress, cyanosis is a critical indicator that warrants immediate attention.
    • When an infant experiences respiratory difficulties, such as inadequate blood oxygenation, the level of oxygen in the arterial blood decreases. This diminished oxygen saturation becomes evident through the bluish tint seen in the skin. Cyanosis is particularly noticeable in areas where blood vessels are close to the skin surface.
  • Stridor
    • A stridor is a distinctive, high-pitched sound that occurs during breathing. This audible indicator typically results from turbulent airflow due to partial obstruction in the upper airways, such as the larynx or trachea.
    • The sound is particularly noticeable during inhalation and can vary in intensity. It can be audible without the aid of medical equipment.
  • Wheezes
    • Wheezing often signals a constriction or blockage in the small airways of the lungs, typically the result of inflammation, secretions, or bronchoconstriction.
    • The wheezing sound is audible during both inhalation and exhalation. It can be described as a whistling or rattling sound and is a key indicator that the air passages are encountering increased resistance.
  • Lethargy
    • Lethargy is characterized by extreme tiredness and a lack of energy. This can be a subtle yet very concerning sign of respiratory distress. When infants struggle to breathe, the increased effort required for each breath can lead to fatigue, causing them to appear unusually quiet, drowsy, or unresponsive.
  • Tachycardia
    • Tachycardia is an abnormally fast heart rate.
    • When infants experience breathing difficulties, the heart often responds by beating faster to compensate for the decreased oxygen levels in the blood. A normal heart rate for a newborn or infant typically ranges from 120 to 160 beats per minute, but it may exceed these limits in the presence of respiratory challenges.
    • Tachycardia serves as a vital physiological response, aiming to enhance oxygen delivery to vital organs.
  • Hypoxaemia
    • Hypoxaemia is a condition characterized by abnormally low levels of oxygen in the blood.
    • Hypoxaemia manifests as a reduction in the levels of oxygen-carrying hemoglobin, resulting in insufficient oxygen delivery to the body’s tissues.
  • Hypercarbia
    • Hypercarbia refers to an elevated level of carbon dioxide in the bloodstream. When infants face breathing challenges, the exchange of gases in the lungs may be compromised, leading to an accumulation of carbon dioxide.