The Science Behind Tummy Time

     

    Prone positioning, or being on the stomach, has gotten alot of attention lately with the rise of patients suffering from Acute Respiratory Distress Syndrome (ARDS) as a result of COVID-19.  Part of the treatment regime in hospitals is the use of prone positioning for 12-20 hours a day whether the patient is on a ventilator or not. Research and clinical experience have shown that starting this treatment piece early in the process is improving outcomes for COVID-19 patients.  Why is that?

    From a physiological standpoint, laying on the back increases the pressure in the chest cavity and compresses the lungs making ventilation more difficult.  It also allows fluid to accumulate in the posterior, or back part, of the lower lobes of the lungs.  Reciprocally, when laying on the stomach, the weight of the heart is shifted onto the rib cage and off of the lungs. The back part of the lungs has the greatest capacity making it important to off load the pressure on these areas to reduce the work of effective breathing.  Laying on the stomach allows gravity to assist with passive expansion of the lobes of the lungs that are in the back and has been shown to improve moving fluid off of those lobes and out of the body.  

    Enter in Severe Acute Respiratory Syndrome (SARS) COVID-19 which targets the lungs and wreaks havoc on the ability of your lung tissue to do its job of transferring oxygen to the body.  Simply put, the virus does this by collapsing the sacs in your lungs and causing them to fill with fluid.  

    We can draw parallels between this treatment method, now widely used during the pandemic and the advice I was given by a Neonatal Intensive Care Unit (NICU) nurse who was caring for my premature son during his hospital stay after birth.  She was the first to tell me that they routinely put premature babies on their stomach to reduce the work of breathing and improve oxygen saturation in the blood.  It turns out that the medical community has been using the prone positioning method as early as the 1970s to treat hypoxia (having low levels of oxygen in the blood) and improve gas exchange (getting oxygen in and carbon dioxide out).  One researcher started a clinical study in 1974 after observing patients with Cystic Fibrosis getting on all fours to catch their breath when they were struggling to breathe.  

    Back to physiology, the muscles of the back, including the muscles that control the ribs which are involved in breathing, are strengthened by laying on the stomach.  Babies who spend the vast majority of their time on their backs often have weak back muscles because they are not given the opportunity to use those muscles.  Use it or lose it!  Or in this case, use it or don't develop it in the first place.  

    Bottom line- tummy time is a good thing for many reasons!  Start early, continue often.  It will help us all breathe easier.