Clinical Guides
Bronchiolitis
A source-grounded paediatric guide to recognising bronchiolitis, grading severity, delivering supportive care and applying Indian facility pathways, prepared for specialist review.
MedNext Academy | 14 min read
Bronchiolitis
A source-grounded paediatric guide to recognising bronchiolitis, grading severity, delivering supportive care and applying Indian facility pathways, prepared for specialist review.
Summary
Bronchiolitis is an acute viral lower respiratory tract illness of infants and young children, characterised clinically by a preceding coryzal illness followed by cough, tachypnoea, increased work of breathing, feeding difficulty, fine crackles and sometimes wheeze. Respiratory syncytial virus is the most common cause, but identifying the virus rarely changes routine management. Diagnosis is clinical. Blood tests, chest radiography and viral testing are not routinely required in a typical case because they add little and radiographic changes can be misread as bacterial pneumonia.
Severity assessment is more important than naming the virus. Measure oxygen saturation with an age-appropriate probe and interpret it alongside respiratory effort, apnoea, feeding, hydration, alertness, age and comorbidity. Young age, prematurity, chronic lung disease, haemodynamically significant congenital heart disease, neuromuscular disease and immunodeficiency increase risk. Apnoea, cyanosis, grunting, marked recession, exhaustion or inability to maintain oxygenation signal emergency care.
Treatment is supportive: maintain airway patency, give oxygen when persistent saturation meets the applicable threshold, support hydration and feeding, minimise handling and monitor for deterioration. Current guidelines advises against routine antibiotics, salbutamol, nebulised adrenaline, hypertonic saline, ipratropium, montelukast, corticosteroids and chest physiotherapy in otherwise typical bronchiolitis. Indian F-IMNCI 2023 includes trial options for some nebulised therapies, creating a real guideline difference that should be resolved through the current institutional protocol and senior review rather than casual polypharmacy. This draft remains quarantined and is not an emergency-care substitute.
How Common Is It?
Bronchiolitis is one of the commonest acute lower respiratory illnesses in infancy and a major reason for hospital attendance during seasonal viral circulation. Most children have a self-limiting illness managed at home, while a smaller group needs oxygen, feeding support or respiratory support. The burden varies by season, climate, crowding, smoke exposure, breastfeeding, prematurity, congenital disease and access to early care. A hospital series cannot be extrapolated to community incidence because it preferentially captures more severe illness and families able to reach care.
Age distribution is diagnostically important. Bronchiolitis is most typical in the first year of life and is considered in children under two. Very young infants may present with apnoea or poor feeding before obvious chest signs. In an older infant or young child with recurrent episodic wheeze, interval symptoms, wheeze without crackles or an atopic history, viral-induced wheeze or early asthma becomes more likely. Definitions vary internationally, so apparent rates can change depending on whether first wheeze only or all viral wheeze under age two is counted.
No current Indian national bronchiolitis incidence is asserted here. The NHM F-IMNCI module is a facility-care manual, not a population surveillance dataset. For clinical practice, prevalence matters less than recognising the seasonal volume, separating mild disease from impending respiratory failure, avoiding unnecessary tests and medicines, and giving carers an explicit deterioration plan. Infection prevention is important because bronchiolitis viruses spread readily between infants in households and wards.
Risk Factors
Risk factors for severe disease include age under three months, especially under six weeks, premature birth particularly before 32 weeks, bronchopulmonary dysplasia or other chronic lung disease, haemodynamically significant congenital heart disease, neuromuscular weakness and immunodeficiency. A previous intensive-care admission, airway anomaly or inability to clear secretions may alter monitoring and respiratory support. These factors do not prove that a child will deteriorate; they lower the threshold for referral, observation and admission when symptoms are evolving.
Environmental risks include household tobacco smoke, indoor air pollution, crowding and close contact with respiratory infection. Breastfeeding is associated with reduced respiratory-infection morbidity, but feeding choice must not be used to blame a family whose child is ill. Day-care or school-age siblings increase viral exposure. RSV and other respiratory viruses are transmitted by droplets, hands and contaminated surfaces, making hand hygiene and equipment separation central in wards.
The ability to manage safely at home is itself a risk assessment. Consider caregiver confidence, health literacy, overnight observation, transport, distance from care, telephone access and whether red flags can be recognised. A numerically reassuring saturation should not override worsening feeding, apnoea or exhaustion. Pulse oximeters may overestimate or underestimate borderline values, and overestimation has been reported in people with darker skin; correct probe selection, a stable waveform and clinical correlation are essential.
Risk of dehydration rises when tachypnoea, nasal obstruction and fatigue reduce breastfeeding or oral intake. Excess intravenous fluid can also be harmful, including where inappropriate antidiuretic hormone secretion occurs. Document intake, urine output and weight when relevant rather than relying on a single impression.
Diagnosis
Bronchiolitis is diagnosed from age, sequence of symptoms and examination. A typical illness begins with one to three days of coryza, followed by persistent cough, tachypnoea or recession and wheeze or crackles. Fever may occur but a high or focal fever should broaden the differential. Grade severity repeatedly because an infant can tire after an initially vigorous respiratory effort.
History
Ask day of illness, coryza, cough, fever, noisy breathing, apnoea, cyanosis, choking, previous wheeze, feeding volume relative to normal, vomiting, wet nappies, alertness and sleep. Record gestational age, chronological and corrected age, neonatal respiratory disease, heart disease, neuromuscular disease, immunodeficiency, previous admissions and current medicines. Ask about sick contacts, smoke or biomass exposure and immunisation. A sudden onset during feeding or play suggests aspiration. Carer reports of apnoea or colour change require serious attention even if the examination is momentarily reassuring.
Examination
Use an ABC assessment. Observe behaviour, tone, colour, respiratory rate, nasal flaring, grunting, head bobbing, recession, air entry, crackles and wheeze. Measure temperature, heart rate and oxygen saturation correctly. Assess hydration from mucosae, tears, capillary refill, urine output and feeding. Look for focal signs, stridor, a murmur, hepatomegaly, asymmetry or toxic appearance suggesting another diagnosis. Exhaustion, reduced effort, recurrent apnoea or failure to maintain saturation despite oxygen indicates impending respiratory failure.
Investigations
Do not routinely order full blood count, inflammatory markers, blood culture, chest X-ray, blood gas or viral panel in uncomplicated bronchiolitis. Consider chest radiography when intensive care is proposed, the course is atypical or pneumothorax, focal pneumonia or another diagnosis is suspected. Blood gas is reserved for severe worsening distress or suspected respiratory failure. Viral testing may support cohorting or infection control but rarely directs individual treatment. Investigate fever in a very young infant using the applicable sepsis pathway.
Differential Diagnosis
Viral-induced wheeze or early childhood asthma is more likely with recurrent episodes, wheeze without crackles, interval symptoms or personal and family atopy, particularly beyond infancy. A first episode with coryza, crackles and diffuse findings favours bronchiolitis. Response to bronchodilator is not a reliable diagnostic test in a young infant and routine treatment is not recommended by current guidelines. Local Indian pathways may use a monitored trial where the diagnosis is unclear; if used, objective response and discontinuation after no benefit must be documented.
Pneumonia is suggested by high fever, focal crackles, bronchial breathing, persistent focal reduced air entry, toxic appearance or a course inconsistent with bronchiolitis. Radiographic changes in bronchiolitis can mimic pneumonia, so chest X-ray should not be used routinely to justify antibiotics. Sepsis, urinary infection and meningitis remain considerations in febrile young infants. Pertussis may cause paroxysmal cough, apnoea and cyanosis with little fever.
Foreign-body aspiration should be considered after sudden choking, unilateral wheeze, asymmetric air entry or unexpected failure to improve. Upper-airway disease causes stridor rather than expiratory wheeze. Congenital heart disease or heart failure may cause tachypnoea, feeding difficulty, sweating, hepatomegaly and poor growth. Airway malacia, vascular ring, cystic fibrosis, aspiration, gastro-oesophageal reflux and an anatomical lung lesion enter the differential with recurrent or atypical symptoms.
Pneumothorax is uncommon but important when a child deteriorates suddenly, has asymmetric air entry or fails oxygen. Metabolic acidosis, severe anaemia and other systemic disease can also produce tachypnoea. The diagnosis should be reconsidered whenever the observed course does not match expected viral bronchiolitis.
Management
Mild bronchiolitis can be managed at home when breathing, hydration, alertness and caregiver circumstances are safe. Explain that cough commonly persists after respiratory distress improves. Encourage continued breastfeeding or small frequent fluids, keep the nose gently clear when obstruction impairs feeding, avoid tobacco smoke and give written red flags. Do not recommend steam inhalation, over-the-counter cough and cold remedies or antibiotics for a viral illness.
In hospital, supportive care is the mainstay. Minimise handling, position comfortably, monitor respiratory effort, saturation, apnoea, intake and urine output, and maintain temperature. Give supplemental oxygen for persistent hypoxaemia using the locally adopted threshold. Current guidelines uses less than 90% for children aged six weeks or older and less than 92% for infants under six weeks or children with underlying conditions. NHM F-IMNCI uses oxygen for severe distress or saturation at or below 90%. Borderline readings require correct measurement and clinical judgement.
Support feeding. If oral intake is inadequate, use nasogastric or orogastric fluids or expressed breast milk where safe. Use intravenous isotonic fluid when enteral feeding is unsafe or respiratory failure is impending, monitoring to avoid overhydration. Consider gentle upper-airway suction only when secretions are causing respiratory distress or feeding difficulty; Current guidelines recommends suction for apnoea.
Escalate to high-flow or CPAP according to local protocol when standard oxygen and supportive measures are insufficient, and involve intensive care for impending respiratory failure. Current guidelines advises against routine salbutamol, nebulised adrenaline, hypertonic saline, corticosteroids, ipratropium, montelukast, antibiotics and chest physiotherapy. Any local deviation should be protocol-driven with a documented indication and response.
Prescribing Information
Bronchiolitis is primarily a condition in which safe prescribing means knowing what not to prescribe. Antibiotics do not treat the viral airway disease and should be reserved for a separately supported bacterial diagnosis. A chest X-ray that shows patchy atelectasis or peribronchial change should not automatically trigger antibiotics. Systemic or inhaled corticosteroids, salbutamol, ipratropium, montelukast, nebulised adrenaline and hypertonic saline are not recommended routinely by current guidelines for typical bronchiolitis. Chest physiotherapy is also avoided unless a relevant comorbidity impairs secretion clearance.
If fever causes distress, use an age- and weight-appropriate antipyretic after checking the current Indian formulary, allergies, hydration, liver or renal risk and prior doses. Antipyretics improve comfort, not the course of bronchiolitis. Never give aspirin to a child for routine fever. Avoid sedating antihistamines, cough suppressants and decongestants in infants; they can cause harm and do not treat lower-airway obstruction.
Oxygen is a prescribed therapy. Document the target, device, flow, response and weaning plan. Ensure nasal prongs fit correctly and are not obstructed by mucus. Escalating oxygen requirement, exhaustion or apnoea requires senior review rather than repeated nebulisation. Fluids are also prescribed: calculate maintenance carefully, account for oral or enteral intake and reassess sodium, urine output and respiratory status when intravenous fluids are needed.
The 2023 Indian F-IMNCI module permits selected trials of adrenaline, salbutamol or hypertonic saline in hospital, while current guidelines recommends against routine use. This discrepancy should not be hidden. Follow the current institutional protocol and senior paediatric decision, record an objective endpoint and stop an ineffective trial. Do not combine therapies reflexively.
When to Refer
Refer immediately for emergency hospital care when there is observed or reported apnoea, central cyanosis, severe respiratory distress, grunting, marked chest recession, respiratory rate above about 70 per minute, exhaustion, reduced responsiveness or a clinician’s impression that the infant is seriously unwell. Provide airway support, oxygen and temperature protection during transfer according to local emergency protocols. Do not send an unstable infant by private transport when an equipped transfer is available.
Consider hospital referral for respiratory rate above 60, persistent room-air saturation below 92%, intake reduced to roughly half to three quarters of normal, clinical dehydration or diagnostic uncertainty. Lower the threshold for age under three months, prematurity, chronic lung disease, significant congenital heart disease, neuromuscular disease or immunodeficiency. Social context matters: remote residence, poor transport, caregiver exhaustion or inability to recognise red flags can make home observation unsafe.
Escalate within hospital for increasing oxygen need, recurrent apnoea, worsening acidosis, inability to protect the airway, exhaustion, failure to maintain saturation despite oxygen, severe feeding compromise or sudden deterioration. Consider high-dependency or intensive care and CPAP or ventilation according to expertise. A sudden change warrants reassessment for pneumothorax, aspiration, sepsis or cardiac disease.
Refer or review atypical cases: recurrent wheeze, focal findings, persistent symptoms beyond the expected course, poor growth, clubbing, stridor, aspiration history or an abnormal cardiac examination. A useful referral reports age and gestation, day of illness, apnoea, respiratory rate and work, saturation on room air and oxygen, feeding percentage, urine output, risk conditions, treatments already tried and response.
Red Flags
Carers need concrete red flags in writing. Seek emergency help for apnoea, blue lips or tongue, grunting, severe chest recession, rapidly worsening breathing, exhaustion, floppiness, poor responsiveness or a child who wakes only after prolonged stimulation. A fall in respiratory rate is not reassuring if effort and alertness are also falling; it can mean fatigue and impending failure. Pulse oximetry at home should not replace assessment of colour, breathing, feeding and responsiveness.
Hydration red flags include intake falling below about half to three quarters of usual, inability to breastfeed because of breathlessness, persistent vomiting, dry mouth or no wet nappy for 12 hours. Very young infants can deteriorate quickly. High fever, toxic appearance, a non-blanching rash, focal neurological signs or a seizure suggests sepsis or another diagnosis and needs urgent review. Sudden cough or distress after choking suggests foreign-body aspiration.
In hospital, recurrent apnoea, rising oxygen requirement, saturation that remains below target despite oxygen, reduced air entry, worsening recession followed by decreased effort, altered consciousness, acidosis or haemodynamic instability requires immediate senior and critical-care assessment. Sudden asymmetric air entry or abrupt deterioration raises pneumothorax.
Safety also includes medicine harm. Sedating cough remedies, unverified nebuliser mixtures and leftover antibiotics should not be given. Smoke exposure worsens respiratory illness; keep the home and vehicle smoke-free. Families should know exactly where to return day or night, how transport will be arranged and when follow-up is expected. Generic advice to come back if worse is not adequate.
Indian Clinical Context
The National Health Mission’s 2023 Facility Based Integrated Management of Neonatal and Childhood Illness participant module provides an Indian facility pathway for bronchiolitis. It identifies first wheeze under two years after coryza, risk factors such as age under 12 weeks and prematurity, supportive oxygen and feeding care, monitoring, infection control and escalation. It also reflects real resource constraints and uses room-air saturation around 90% within its oxygen and discharge pathway.
There is a material treatment difference between sources. NHM F-IMNCI allows nebulised adrenaline, a response-limited salbutamol trial in selected severe disease and hypertonic saline in hospital. current guidelines explicitly recommends none of these routinely. This guide uses supportive care as the default and does not convert the Indian module’s optional wording into a universal prescription. Each facility should reconcile its current paediatric protocol with the evidence, available monitoring and senior expertise. An undocumented series of nebulisers is poor care when feeding, oxygen and deterioration are not being assessed.
Indian home assessment must include distance to care, transport, caregiver language, tobacco and biomass exposure, and ability to continue breastfeeding or expressed milk. Do not prescribe costly investigations merely because inpatient observation is difficult. Conversely, do not discharge a high-risk infant because beds or oxygen are scarce without a documented escalation and safety plan.
Cohorting, hand hygiene and dedicated tubing reduce cross-infection in crowded wards. Viral panels may be unavailable and are usually unnecessary. No Indian national incidence estimate is asserted from this facility manual. Local antimicrobial and oxygen policies should be current, and pulse-oximeter limitations on darker skin must be considered near treatment thresholds.
NMC Competency Mapping
The NMC CBME Curriculum 2024 maps bronchiolitis within Paediatrics competency PE25.6. The learner should describe the aetiopathogenesis, diagnosis, clinical features, management and prevention of lower respiratory infections including bronchiolitis, wheeze-associated LRTI, pneumonia and empyema. PE25.6 is core, has a predominant skill domain and a Show How level, with bedside clinics, small-group teaching and lectures suggested.
At Know and Know How level, learners should recognise the coryzal prodrome, diffuse crackles or wheeze, feeding impairment and age distribution; identify RSV without assuming viral testing is required; list severe-disease risks; and distinguish bronchiolitis from pneumonia, foreign-body aspiration and recurrent viral wheeze or asthma. They should understand pulse-oximeter limitations, why routine imaging and blood tests are avoided, and why supportive care is the treatment foundation.
At Show How level, a student should assess airway, respiratory effort, saturation, hydration and feeding; identify apnoea, cyanosis and exhaustion; demonstrate safe oxygen delivery and nasal-care principles; calculate and monitor feeding or fluid support under supervision; communicate red flags; and escalate appropriately. Prescribing or respiratory support remains supervised and follows local policy.
Prevention includes hand hygiene, reducing smoke exposure, breastfeeding support and infection-control separation in hospital. Integration spans respiratory physiology, virology, nutrition, emergency triage, oxygen therapy and family communication. Assessment should reward avoidance of harmful routine therapy as well as recognition of severe disease. Formal mapping should preserve PE25.6 and use the current institutional skills log.
Key Exam Pearls for NEET PG
Bronchiolitis is a clinical diagnosis in an infant or child under two, typically after coryza, with cough, tachypnoea, recession, fine crackles and wheeze. RSV is the commonest cause. Young infants may present with apnoea. Recurrent episodic wheeze, interval symptoms and atopy in an older child favour viral-induced wheeze or asthma. Sudden unilateral wheeze after choking suggests a foreign body.
Do not routinely order chest X-ray, blood tests, blood gas or viral testing. Radiographic changes may mimic pneumonia and promote unnecessary antibiotics. Measure saturation correctly and assess feeding and hydration. Severe signs are apnoea, cyanosis, grunting, marked recession, respiratory rate over 70, exhaustion or failure to maintain saturation despite oxygen.
Treatment is supportive: oxygen for persistent hypoxaemia, breastfeeding or small feeds, nasogastric or intravenous fluid when needed, selective gentle suction and escalation to CPAP for impending failure. Current guidelines advises against routine salbutamol, adrenaline, hypertonic saline, antibiotics, ipratropium, montelukast, steroids and chest physiotherapy. Know that NHM F-IMNCI 2023 permits selected monitored nebulised trials; state the guideline context rather than blending recommendations.
current guidelines oxygen thresholds are persistent saturation below 90% from six weeks of age and below 92% under six weeks or with underlying disease. NHM uses severe distress or saturation at or below 90% in its facility module. For discharge, require clinical stability, adequate feeding and sustained room-air saturation under the applicable protocol. Safety-net apnoea, cyanosis, worsening work, exhaustion and no wet nappy for 12 hours.
Frequently Asked Questions
Does every infant with bronchiolitis need a chest X-ray?
No. Typical bronchiolitis is diagnosed clinically, and routine chest X-ray can show changes that mimic pneumonia and lead to unnecessary antibiotics. Imaging is considered when the course is atypical, focal disease or pneumothorax is suspected, sudden deterioration occurs, or intensive care is being proposed. Severity assessment and feeding are more useful routinely.
Why are salbutamol and antibiotics usually not prescribed?
Bronchiolitis is a viral small-airway illness, and bronchodilator response is inconsistent because obstruction is driven largely by oedema and mucus rather than asthma-type bronchospasm. Antibiotics do not treat viruses. Current guidelines recommends neither routinely. Use antibiotics only for a separate bacterial diagnosis and follow a current local protocol for any monitored bronchodilator trial.
Which symptoms mean a baby needs emergency reassessment?
Apnoea, blue lips or tongue, grunting, marked chest recession, rapidly worsening breathing, exhaustion, floppiness, poor responsiveness, inability to feed, no wet nappy for 12 hours, collapse or a seizure requires urgent assessment. A baby who breathes more slowly while becoming drowsy may be tiring, not improving. Call the local emergency service.
How long can cough continue after bronchiolitis improves?
Cough often persists after feeding and work of breathing have improved, and resolution can take several weeks. The trend should be toward easier breathing, better intake and normal alertness. Reassessment is needed for recurrent apnoea, new fever, focal signs, worsening after initial improvement, poor weight gain or symptoms that are prolonged or recurrent enough to suggest another diagnosis.
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