27.1 Pediatric Respiratory Disorders: IMCI Danger Signs and Cough Assessment, URI, Tonsillitis & Peritonsillar Abscess, Croup, Epiglottitis, Foreign Body, Bronchiolitis, Pneumonia, Pleural Effusion and Complications

Why this area matters

The TOS respiratory competencies are to:

• recall the burden and age, sex and racial predilection of respiratory disorders;
• recognize their signs and differential diagnosis;
• select and interpret laboratory tests;
• manage them and their complications and emergencies;
• promote health and prevention and refer appropriately.

Pneumonia is a leading cause of death in Filipino children under 5. Most deaths could be prevented by recognizing fast breathing and danger signs early, giving antibiotics, oxygen and vaccines (pentavalent, PCV, measles), and treating malnutrition.

The IMCI Framework: Color-Coded Triage and General Danger Signs

IMCI utilizes an action-oriented, color-coded triage matrix based on clinical signs rather than laboratory-dependent diagnoses:

• Pink Row (Severe Classification): Requires immediate pre-referral urgent treatment (e.g., first-dose parenteral antibiotic, sugar water for hypoglycemia, tactile warming) and urgent referral to a hospital facility.
• Yellow Row (Moderate Classification): Requires specific medical treatment at the outpatient clinic (e.g., oral antibiotics, oral rehydration therapy, antimalarials), caregiver education, and a mandatory follow-up visit in 2 to 5 days.
• Green Row (Mild Classification): Requires supportive home care, advice on continuing feeding and increasing fluids, and counseling on when to seek immediate medical attention.

The Four General Danger Signs (Mandatory Screening in Every Child)

Before evaluating organ-specific complaints, every child aged 2 months to 5 years must be screened for the four General Danger Signs:

1. Is the child unable to drink or breastfeed?
2. Does the child vomit everything?
3. Has the child had convulsions during the current illness?
4. Is the child lethargic or unconscious?

Decision Rule: The presence of even a single General Danger Sign immediately classifies the child into the PINK (Severe) category, requiring emergency stabilization and immediate referral.

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Cough and Difficulty Breathing: The IMCI Respiratory Algorithm

Acute respiratory infections represent the leading cause of under-five mortality. Under IMCI, assessment hinges on three objective physical signs: respiratory rate, chest indrawing, and stridor.

Fast Breathing Cutoffs by Age Group

The respiratory rate must be counted for one full minute while the child is calm and not crying.

• Age under 2 Months (Sick Young Infant): $\ge 60\text{ breaths per minute}$
• Age 2 to 11 Months: $\ge 50\text{ breaths per minute}$
• Age 12 to 59 Months: $\ge 40\text{ breaths per minute}$

IMCI Cough and Breathing Classification Table

The current WHO IMCI chart booklet (2014 revision) classifies a child aged 2 months up to 5 years as follows. Older national charts placed chest indrawing in the pink row, so always follow the DOH chart booklet in use.

Upper respiratory infections

• The common cold (viral URI): rhinovirus and others cause rhinorrhea, nasal congestion, sore throat and mild fever for 7 to 10 days. Antibiotics do not help.
  • Green or yellow nasal discharge alone does not mean bacterial infection.
  • Suspect bacterial sinusitis with symptoms lasting 10 days or more without improvement, severe onset with high fever, or worsening after initial improvement.
  • Acute otitis media shows a bulging tympanic membrane and is treated with high-dose amoxicillin when indicated.
• Tonsillopharyngitis:
  • viral in most young children, especially under 3;
  • group A streptococcal infection is more likely in school-age children with fever, exudate, tender anterior nodes and no cough;
  • confirm with a rapid antigen test or culture where available, and treat strep with penicillin or amoxicillin for 10 days.
• Peritonsillar abscess (quinsy):
  • in older children and adolescents;
  • severe unilateral sore throat, trismus, a "hot potato" voice, drooling and uvular deviation away from the swelling;
  • treat with needle aspiration or incision and drainage plus antibiotics.
• Retropharyngeal abscess: in younger children, with fever, neck stiffness or reluctance to extend the neck, and a widened prevertebral space on lateral X-ray.

Viral Croup (Laryngotracheobronchitis)

• Etiology: Parainfluenza virus (Types 1 and 2).
• Typical Patient: Infant or toddler aged 6 months to 3 years.
• Clinical Presentation: Prodrome of URI followed by a barking 'seal-like' cough, inspiratory stridor, and hoarseness, characteristically worsening at night.
• Radiography: Anteroposterior soft tissue neck radiograph reveals symmetrical subglottic narrowing known as the 'steeple sign' or 'pencil-point sign'.
• Pharmacologic Management:
  • Mild Croup: Single dose of Oral Dexamethasone ($0.15\text{ to }0.60\text{ mg/kg}$). Long half-life (36-72 hours) suppresses laryngeal edema.
  • Moderate to Severe Croup (Stridor at Rest, Retractions): Nebulized Racemic Epinephrine (2.25% solution: 0.05 mL/kg, max 0.5 mL) or standard L-epinephrine (1:1,000 solution: 0.5 mL/kg, max 5 mL) with supplemental oxygen. Observe in the clinic for at least 2 to 4 hours to monitor for potential rebound mucosal edema after the adrenergic vasoconstrictive effect wanes.

Acute Epiglottitis

• Etiology: Historically Haemophilus influenzae type b (Hib); now includes Streptococcus pneumoniae, Group A Streptococcus, and Staphylococcus aureus in vaccinated populations.
• Typical Patient: Child aged 2 to 7 years.
• Clinical Presentation: Abrupt, hyperacute onset of high fever, toxic appearance, severe sore throat, and the 'Four Ds': Drooling, Dysphagia, Dysphonia (muffled 'hot potato' voice), and Distress (inspiratory stridor).
• Characteristic Posture: Sits upright in the 'tripod' or 'sniffing' position (leaning forward with hands on knees, neck hyperextended, chin thrust forward, and mouth open to maintain an open airway).
• Radiography: Lateral soft tissue neck radiograph reveals an enlarged, edematous epiglottis protruding into the hypopharynx, known as the 'thumbprint sign'.
• ABSOLUTE EMERGENCY RULE: DO NOT AGITATE THE CHILD. NEVER examine the pharynx with a tongue depressor, draw blood, or separate the child from the parent in an unmonitored setting. Any invasive manipulation can trigger fatal laryngospasm and immediate complete airway occlusion. Transfer the child immediately to the operating room accompanied by an anesthesiologist and otolaryngologist for definitive endotracheal intubation under inhalation anesthesia, followed by IV Ceftriaxone ($50-100\text{ mg/kg/day}$) or Cefotaxime.

Foreign Body Aspiration

• Peak Incidence: Children aged 1 to 3 years (toddlers exploring food items such as peanuts, seeds, and hot dogs, or small toy components).
• Clinical Presentation: Sudden, witnessed paroxysm of acute choking, coughing, and cyanosis, followed by a quiescent phase. Physical examination classically reveals unilateral diminished breath sounds and unilateral expiratory wheezing that does not respond to bronchodilators.
• Radiography: Inspiratory and expiratory chest radiographs (or bilateral decubitus views) demonstrate air trapping and hyperinflation on the affected side (the foreign body creates a one-way 'ball-valve' effect allowing air entry during inspiration but preventing egress during expiration), with contralateral mediastinal shift.
• Definitive Management: Rigid Bronchoscopy under general anesthesia for diagnostic visualization and therapeutic extraction of the foreign object. (Flexible bronchoscopy is unsuitable for foreign body extraction due to lack of airway control and grasping instruments).

Bronchitis and bronchiolitis

• Acute bronchitis in children is viral, with cough lasting up to 3 weeks and no tachypnea. Antibiotics are not needed. Cough lasting more than 4 weeks needs evaluation for asthma, TB, pertussis, foreign body or chronic suppurative lung disease.
• Acute bronchiolitis:
  • an infection of infants under 2 years, peaking at 2 to 6 months, mostly caused by respiratory syncytial virus (RSV);
  • a coryza prodrome, then cough, wheeze and fine crackles, tachypnea, retractions and feeding difficulty;
  • apnea in young or premature infants.
• Management of bronchiolitis:
  • nasal suction, feeding support and oxygen if saturation is low, with monitoring;
  • routine bronchodilators, corticosteroids, antibiotics and chest physiotherapy are not recommended.
• High-risk infants: preterm infants and those with heart or lung disease. Monoclonal antibodies prevent RSV disease in some settings.

Pneumonia in children

• Causes by age:
  • neonates: group B streptococcus, Gram-negatives;
  • 1 to 3 months: C. trachomatis (afebrile pneumonia with staccato cough and conjunctivitis) and pertussis;
  • under 5 years: viruses (RSV, influenza, others) and S. pneumoniae, the most common bacterial cause;
  • school age: Mycoplasma is common.
  • S. aureus causes necrotizing pneumonia with pneumatoceles and empyema.
• Assessment:
  • fast breathing, chest indrawing, grunting, nasal flaring and hypoxemia;
  • crackles or bronchial breath sounds;
  • a chest X-ray is not needed for mild cases at the outpatient level.
• Philippine guideline: the Philippine Academy of Pediatric Pulmonologists stratifies children by risk class (pCAP A to D). Low-risk children are treated at home with oral amoxicillin. Moderate- and high-risk children (dehydration, inability to feed, hypoxemia, altered sensorium, severe distress or malnutrition) are admitted for IV antibiotics and oxygen.
• Prevention: pentavalent vaccine (Hib), PCV, measles vaccination, exclusive breastfeeding, good nutrition and clean indoor air (no smoke from tobacco or biomass fuel).

Pleural effusion and complications

• Pleural effusion:
  • Causes: parapneumonic (most common in children), tuberculous (lymphocytic, high protein, high adenosine deaminase), nephrotic syndrome or heart failure (transudates), and malignancy.
  • Light's criteria separate exudates from transudates.
  • Empyema: frank pus, organisms on Gram stain or culture, or pH below 7.2 and low glucose. It needs chest tube drainage with antibiotics, plus fibrinolytics or VATS for loculations.
• Acute respiratory failure:
  • Type 1 (hypoxemic): PaO2 below 60 mmHg, as in pneumonia and ARDS.
  • Type 2 (hypercapnic): PaCO2 above 50 mmHg with acidosis, as in airway obstruction, neuromuscular weakness and exhaustion.
  • A "normal" PaCO2 in a child in severe asthmatic distress signals tiring and impending failure.
• Acid-base disorders: acute respiratory acidosis (hypoventilation) and respiratory alkalosis (hyperventilation, early sepsis, salicylate toxicity). Metabolic acidosis from shock, dehydration or DKA drives compensatory tachypnea.
• Pneumothorax: sudden pain and breathlessness with reduced breath sounds and hyperresonance.
  • Tension pneumothorax (tracheal deviation, hypotension) needs immediate needle decompression, then a chest tube.
  • Risk factors: asthma, staphylococcal pneumonia, ventilation and tall thin adolescents.
• Pneumomediastinum: follows asthma, vomiting or forceful coughing. It causes chest pain, subcutaneous emphysema in the neck and a crunching sound with the heartbeat (Hamman sign). It is usually managed conservatively.