The titrated strain is the pressure of air at which most (if not all) apneas and hypopneas have been prevented, and it is usually measured in centimetres of water (cmH 2 O). The strain required by most patients with sleep apnea ranges between 6 and 14 cmH 2 O. http://augustjsojf.free-blogz.com/17312889/recognising-realistic-secrets-in-the-opportunities-in-cpap-machines