Thursday, August 8, 2019

Understanding Breathing problems in Rett Syndrome

Breathing problems are a major challenge in patients with Rett syndrome (RS) and they are more apparent in day-time but irregular breathing issues can be noticed during sleep too. During day-time patients can show episodes of hyperventilation and irregular hyperventilation patterns which can vary in severity, onset, duration and type of the breathing issues.Many times the breathing issues or abnormalities are mistaken as epileptic seizures which can lead to child being administered inappropriate medicines. So it is important to understand the type of breathing issues which are mostly reported in patients with RS to manage the same properly. 
Different types of breathing irregularities has been reported in the RS patients including hyperventilation, Hypo-ventilation, breath holding episodes, apnoeas, apneustic breathing, valsalva manoeuvres, periodic breathing and tachypnoea (abnormally rapid breathing). It is important to understand these type of irregularities and what effects they can have on the child.
In apneustic breathing the girls are breathing in but they fail to breathe out on regular intervals and the types of abnormalities included in this category are long breath holding episodes, repeated short breath holding and longer inhaling episodes. As per literature, the RS girls with apneustic breathing responds to drugs.
In forceful breathing the girls are doing forceful inhaling and exhaling of the air and they would often lose a good amount of carbon dioxide from their bloodstream. In this type, the breathing may stop leading to symptoms like epileptic stiffness of the limbs. The skin may turns white and the body may becomes floppy or their face/lips may turn blue. Breathing abnormalities included in this category are hyperventilation, deep breathing and tachypnoea (abnormally rapid breathing)These type of breathing issues does not respond to drugs, but there may be a requirement to raise the level of carbon dioxide in the bloodstream back to normal.

The girls with feeble breathing are shallow breathers that means the movements of the abdomen and chest so shallow/small that parents may think that the girl has stopped breathing. Sometimes the girls indeed do stop breathing briefly. The major effect seen in patient due this type of breathing is rise of carbon dioxide in the blood, which will ultimately excite the brainstem. Most of the time there is enough oxygen supply to the body in this type of breathing but the girl's face and lips may turn blue due to lack of oxygen. Careful attention should be given before giving any medication to the feeble breather so that medicine should not aggravate the situation. Feeble breathers can tolerate medicines related to general anesthesia as long as drugs which can depress respiration are avoided. Current research is more focused on these kind of breathing abnormalities to understand whether this type of breathing responds to drugs or not. 

Valsalva’s type of breathing is forceful breathing leading to an increase of pressure in the chest and the lungs, reducing the blood flow to the heart. This has more severe effect on the brainstem. This kind of breathing can result in  dizziness, unsteadiness, and wandering eyeballs and also affects the blood pressure. Sometimes the symptoms of this kind of breathing irregularities are confused with epileptic seizures and this kind of irregularities does not respond to medications. There are periodic changes in the EEG along with severe drop in blood pressure in some of the girls which can be mistaken for abnormal changes in the EEG due to seizures