Paediatric pulmonologists specialise in treating children with breathing problems. Commonly-treated treated include asthma, pneumonia, wheezing and bronchitis
Other patients may include babies with sleep apnea, children who require oxygen to help them breathe and children with cystic fibrosis.
Pulmonary function testing
Pulmonary function testing (PFT) in children plays an important role in the evaluation of the child with known or suspected respiratory disease. It is an important tool for diagnosis, monitoring response to treatment and complications, measuring the impact of environmental factors, in addition to predicting prognosis.
Spirometry
Spirometry refers to a lung function test done in children to assess airway obstruction. Asthma and cystic fibrosis are examples of lung diseases that cause airway obstruction in children. Spirometry can also be used to assess restrictive lung diseases like kyphoscoliosis and muscular dystrophy.
Co-operative children from the age of five years can successfully perform spirometry. After first taking a deep breath to total lung capacity the child blows out as hard and fast as possible and then empties his lungs completely. By observing the shape of the curve on the flow volume loop and checking the measurements the doctor can then evaluate what type of disease the child has. Often a bronchodilator like salbutamol is given after the first series of tests to see if there is improvement after the bronchodilator. A positive bronchodilator response test is highly suggestive of asthma.
Exercise challenge test
When the diagnosis of asthma is uncertain an exercise challenge test becomes more important. Young children need to first exercise for four to six minutes and then they need to reach their target heart rate within four minutes. Spirometry is then done at five, 10, 15, 20 and 30 minute intervals post exercise. A fall in FeV1 of 15% is indicative of exercise induced bronchoconstriction and suggestive of asthma.
Lung volumes
The measurement of lung volumes is important in clinical conditions in which a restrictive lung defect and/or air trapping may be present. It is also important when addressing possible diffusion capacity defects.
For this test your child will sit inside a cubicle that looks similar to a telephone box. During the time in the box your child will perform a range of breathing exercises, which will allow us to calculate the volume of air in the lungs.
Impulse oscillometry
In children younger than five years old spirometry often cannot be reliably performed. In this instance an impulse oscillometry test can be performed as it requires less effort and co-operation from the young child than spirometry.
The technique involves sending multiple sound waves generated by a computer-driven loudspeaker to the lungs during normal tidal breathing. Respiratory resistance and respiratory reactance is then measured. These parameters provide information about the mechanical properties of the airway and parenchyma.
Impulse oscillometry has a greater sensitivity to detect peripheral airway obstruction than spirometry. Using impulse oscillometry, the pulmonologist can tell if the airway obstruction is in the large airways or small airways. Studies have shown that monitoring small airway function by impulse oscillometry can be useful in identifying children who are at risk of losing asthma control.
High altitude simulation test / hypoxic challenge test (fitness to fly test)
The partial pressure of oxygen inside the aircraft is lower than what we breathe in room air (at sea level). Therefore, most passengers will experience a decrease in oxygen saturation – the amount of oxygen circulating in the body. This is normally tolerated well in healthy individuals. People with cardiac and respiratory problems however, may experience complications. The hypoxic challenge will help evaluate how well your child will tolerate the reduced oxygen levels in the aircraft cabin and whether supplemental oxygen is required during a flight.
Flexible bronchoscopy
Flexible bronchoscopy is a test where a small bronchoscope (camera) is passed into your child’s airways to actually see what the lungs look like. This test allows the doctors to see if there are any airways squashed (e.g. by glands) or if the airways look inflamed. It is usual to perform a “lavage” at the same time as the bronchoscopy. This is a test where an amount of saline (salt water) is washed into the lungs, and immediately sucked back out again. In doing this we can get better samples of mucus from which we can look for organisms, and sometimes also look for evidence of other, more complicated problems. The lavage doesn’t cause any serious or long term side effects. If a bronchoscopy (with or without lavage) is thought to help towards your child’s care, your doctor will discuss this with you.
Most of the risks of bronchoscopy are those related to the general anaesthetic.
Once a bronchoscopy has been done the child can usually be discharged in the afternoon of the day of the procedure.
