Q: My niece was just admitted to the hospital for bronchiolitis. How is this different from bronchitis that adults get?
A: Thanks for your question. Bronchiolitis is a common childhood viral infection, falling somewhere between a cold and pneumonia.
Our respiratory tree extends from the nostrils all the way down to our alveoli, the small air sacks deep within our lungs. Air passes down 23 generations of branching airways to the alveoli, where gas exchange occurs across very thin membranes. Each generation of airway gets smaller as it goes further toward the alveoli. The large airways are called bronchi and the smaller ones are bronchioles.
Bronchi commonly get inflamed and infected in adults, resulting in mucus and coughing called bronchitis, and treated with antibiotics.
In children under the age of 2, the inflammation from a cold virus spreads quickly and often extends into the bronchioles, causing bronchiolitis.
Bronchioles are easily obstructed by mucus, which leads to congestion and collapse of the alveoli just beyond. During this process, the child can show increasing work of breathing, trying to compensate for the blocked airways and collapsed lung segments.
Most viral infections causing bronchiolitis last between one and two weeks. The worst symptoms may occur near the end of the first week. Common viruses include respiratory syncytial virus (RSV), influenza virus and rhinovirus, among others.
Bronchiolitis typically begins with cold symptoms – runny nose, congestion, cough – and may progress to increasing respiratory distress with rapid breathing, wheezing, and visible pulling in of the chest and abdomen.
Bronchiolitis is responsible for approximately 100,000 pediatric hospital admissions annually in the United States.
Initially, the child will appear to have a cold, which will gradually worsen to include fever, cough and congestion. Smaller babies may become dehydrated due to decreased oral intake. Babies under the age of 1 are obligate nose breathers, which means that a stuffy nose makes it very hard to breathe and drinking or breast feeding with a stuffy nose can be difficult.
Suctioning out their nose with a bulb suction can improve things immensely.
Some babies will get sicker and end up at the pediatrician’s office where the doctor will assess the baby’s work of breathing and check their oxygen saturation. If the work of breathing increases, or the oxygen saturation is decreased, the baby may be admitted to the hospital. A typical stay is four to 10 days. During that time, the child will receive what we call supportive care, which consists of suctioning, rehydration with fluids and oxygen via nasal cannula. Supportive care does not include antibiotics. This is because bronchiolitis is a disease caused by viruses and antibiotics have no effect on viruses. Antibiotics only treat infections caused by bacteria.
If the child is sick enough to be admitted to the pediatric intensive care unit, they may also receive a chest X-ray, a trial of an albuterol nebulizer and be asked not to eat or drink anything until their breathing eases.
In some cases, the baby’s work of breathing may become overwhelming, causing total body stress and fatigue. Despite maximum effort, the baby may not be able to maintain adequate oxygen saturation. For these children, the next level of care is intubation and mechanical ventilation. The ventilator helps the child breathe, giving bigger and more breaths, and more oxygen, than the child could manage on their own.
Children, even babies, usually recover from this illness well, with no long-term effects.
Studies have shown that infants hospitalized with RSV or rhinovirus bronchiolitis have an increased risk of recurrent wheezing during the first 10 years of life, but not necessarily of long-term asthma.
It is possible to have back-to-back episodes of bronchiolitis and even to have multiple admissions to the hospital during the same season.
Good handwashing and excellent nasal suctioning are important. The viruses that cause bronchiolitis are contagious, spreading through touch and coughing/sneezing. It is thought that 3 feet is a safe distance. Washing your hands before picking up or your baby is a good idea. Hand sanitizer is also effective, if used properly.
Some babies qualify for a preventive medication called palivizumab. This is an antibody that helps minimize the severity of RSV bronchiolitis, should the baby contract it. It is used for very premature babies or babies with cyanotic congenital heart disease.
Bronchiolitis season is from November through April annually, and we are seeing many children in our clinics and in our hospital.
Do not hesitate to contact your pediatrician if you feel your child’s cold is becoming more severe and requires more attention.
Anjali Subbaswamy is a Pediatric Intensive Care Physician at UNM. Please send your questions to her at ASubbaswamy@salud.unm.edu.