Parasternal Intercostal Electromyography: a Novel Tool to Assess Respiratory Load in Children Victoria MacBean, Caroline J. Jolley, Timothy G. Sutton, Akash Deep, Anne Greenough, John Moxham, Gerrard F. Rafferty
Published in the journal Pediatric Research, May 11th 2016
Parasternal intercostal electromyography (EMGpara) is a new way to measure breathing difficulty. Research needs to be carried out because body parts used in breathing, like the lungs, need to be properly checked over for breathing problems to be managed, but the testing methods aren’t always suitable for children who are very young or ill. The parasternal intercostal muscles are muscles that move at the same time as the diaphragm (a thin sheet of muscle under the lungs) when you breathe in and out. EMGpara measures signals from the brain which are sent to these muscles without putting any instruments into the body, so it is ideal for children.
EMGpara was measured using stickers on the front of the chest while the participants (92 healthy, 20 wheezy and 25 with a machine (ventilator) to help them breathe) were breathing in and out in a resting state. For the wheezy children, measurements were taken before and after a substance to widen air passages (reliever inhaler, or bronchodilator) was used; for the critically ill children, these were taken during ventilator-assisted breathing, then with just mild air pressure to keep the airways open (continuous positive airways pressure).
It was found that as age, weight and height increased, EMGpara decreased. This is because when children are growing up, big changes take place in the respiratory system, decreasing the effort needed for breathing. EMGpara in the healthy children was the lowest; in the wheezy children it was higher before the bronchodilator was used, dropping to similar levels to the healthy children afterwards. In the critically ill children, EMGpara was higher than in the wheezy children when the ventilator was used, and even higher with continuous positive airways pressure when they were having to breathe without support.
This study has shown that measuring EMGpara is possible in children of a range of ages and levels of health. The results from the healthy children have shown important age-related changes in EMGpara, and those from the wheezy and critically ill children have shown that EMGpara is affected by changes in how hard the breathing muscles have to work because of different diseases and treatments. EMGpara could be a really helpful method in testing the breathing ability of patients who are usually difficult to assess.
This summary was produced by Lottricia Millett, Year 12 student from Burntwood School, Wandsworth, as part of our departmental educational outreach programme.