It is a condition that results in inflammation of the bronchioles, the smallest airways in the lungs and presents with coughing, wheezing, shortness of breath with secondary difficulty in feeding.
It is caused by the Respiratory Syncytial Virus in 70% of cases and is much more common in the winter months in Temperate countries.
Treatment for Bronchiolitis is often supportive and symptomatic.
Signs and Symptoms
Coughing, Wheezing, Shortness of breath over one to two days, followed by crackles and/or wheezing are typical presentations of Bronchiolitis.
After the episode, it is common for the airways to remain sensitive for several weeks, leading to recurrent cough and wheezing.
Severe signs of the disease include:
- Poor feeding (less than half of usual fluid intake in preceding 24 hours)
- Lethargy
- History of apnea
- Respiratory rate >70/min
- Presence of nasal flaring and/or grunting
- Severe chest wall recession
- Cyanosis
Causes
The Respiratory Syncytial Virus is responsible for up to 70% of cases. Other viruses include the common influenza virus, coronavirus, adenovirus, rhinovirus, and other respiratory viruses.
Some studies have suggested a connection between voluntary caesarean births and bronchiolitis. This link becomes more prominent in studies done amongst premature babies, those with low birth weights and/or congenital heart defects.
On a lighter note, studies also show evidence that breastfeeding provides some protection against bronchiolitis.
Diagnosis
Diagnosis of Bronchiolitis is clinical. A chest X-ray is useful to exclude bacterial pneumonia but it is not indicated in routine cases. Testing for specific viral strains can be done but has a low risk - benefit ratio as identifying the virus has little effect on management.
As bronchiolitis is often caused by a virus, antibiotics are not indicated unless a superseding bacteria infection occurs. Some studies have shown that as low as 6% of affected infants develop superseding bacteria infections concurrently.
Prevention
Basic procedures like handwashing, avoiding exposure to symptomatic individuals, good hygiene and maintain a strong immune system are the best forms of protection against the Respiratory Syncytial Virus. Breast milk contains antibodies from the mother and hence confer immunity to the infant, especially during the first month of life. Immunizations for premature infants are also available but it should only be administered to infants that meet specific criteria.
Treatment
High flow oxygen therapy with a high flow device that can provide precise flow/FiO2 and medical grade vapor forms an important part of the management of bronchiolitis.
As mentioned, treatment for Bronchiolitis is primarily symptomatic and supportive. Some drugs like Bronchodilators have been used with a fair margin of success.
Bronchodilators
Inhaled Epinephrine has been shown to reduce total length of Hospital stay when compared to Salbutamol. Salbutamol, on the other hand, when administered via the inhalation route, has also been shown to reduce initial hospital admission rates in some studies but has no no clear effect on the length of hospital stay.
The routine use of bronchodilators in children with bronchiolitis is however not recommended as there has been no clear effect on any important outcomes in children but carries with it a small risk of potential adverse effects from the administered drugs and hence should be used with care and under medical supervision.
Currently other medications do not yet have evidence to support their use. Antiviral drugs like Ribavirin have not been shown to be effective. Administration of Antibiotics in the event of a complicating bacterial infection will have no effect on the underlying viral infection. Corticosteroids also have not shown proven benefits in Bronchiolitis.
Epidemiology
90% of the people affected are between 1 and 9 months old. Bronchiolitis is the most common cause of hospitalization up to the first year of life especially during winters in temperate countries.
About The Author
Dr Lau Tzun Hon is a resident housecall doctor at CMY Medical. He received his MBBS (Hons) from Sydney University in 2001 and has served in the both private and government restructured hospitals prior to commencing his practice in Home Care.
While in the Government Restructured Hospitals, Dr Lau served primarily in the Department of Accident & Emergency Medicine and Anaesthesia. Upon entering the Private sector, Dr Lau worked in both public and private A&E departments before venturing into Home Care.
Over the years, he has developed a strong passion to maintain and enhance the quality of life for patients under his care. A strong believer that healthcare does not need to be financially straining, Dr Lau often delivers more value beyond expectations.
No comments:
Post a Comment