Past, Present and Future of CPAP
Colin Sullivan, M.B.B.S., Ph.D, FRACP – the inventor of continuous positive airway pressure (CPAP) – received the Sleep Innovator Award at the National Sleep Foundation’s Annual Awards Dinner during National Sleep Awareness Week® 2009. We asked Professor Sullivan to share his thoughts about the past and future of CPAP.
What were some of your pivotal moments in the laboratory, and how have these discoveries changed the treatment of sleep apnea?
The pivotal moment was a night in June 1980 when we first tested the idea that positive pressure, applied just through the nasal airway, could stop obstructive apnea. Although I had the idea several months previously, at that time we saw only very few patients, so we had to wait for an appropriate patient to do the experiments. The patient in whom the first test was done had very severe sleep apnea and had come under my care at the Royal Prince Alfred Hospital where I was a physician in the Respiratory Unit. He was so severe that I had recommended a tracheotomy as an urgent procedure. However, he and his family refused surgery, but he was happy to volunteer for the pressure experiment. We put together the breathing circuit in the afternoon, and then used plastic tubes and a rapid setting silicone sealant to provide access to the nasal airway. Within minutes of the full polysomnography (PSG) set-up, the patient had gone to sleep and developed repetitive severe sleep apnea. I gradually increased the air pressure in the circuit, and then suddenly the apnea stopped and normal breathing appeared. It was an incredible result. As we watched in amazement, the patient went into REM sleep. I quickly decided to repeat the experiment by dropping the pressure and the apnea recurred. I went through a series of cycles increasing the pressure and so literally “turning off” the apnea, and then dropping the pressure and “turning on” the apnea. There was no uncertainty or ambiguity. The method worked. The effect was so clear and repeatable, the next question to answer was would it work all night?