1996 OPEN FORUM Abstracts
Principles of CPAP Titration
Pamela Minkley, RRT, RPSGT Wednesday, November 6, 1996
Principles of NCPAP Titration Nasal continuous positive pressure (NCPAP) therapy is now a common treatment for obstructive sleep apnea and other obstructive respiratory events which disturb sleep and cause cardiopulmonary pathology. Historically patients suspected of having obstructive sleep apnea (OSA) or other respiratory events during sleep were studied one full night in the sleep center without treatment intervention and then returned to the center for one full night of treatment intervention and titration. The treatment intervention usually involved application of NCPAP and possibly oxygen. Today, most patients are studied the first half of the night without intervention and if specifically defined evidence of obstructive respiratory events is present, the study is interrupted and therapy is initiated and titrated. In the near future, many of these patients may be screened for obstructive respiratory events and titrated on NCPAP at home, in one night, with self reporting and self adjusting or "smart" NCPAP units. To adequately treat OSA patients or to interpret the data from these new systems, the polysomnographic technologist must have a through understanding of the function of NCPAP devices, the physiology of obstructive respiratory events during sleep, the contraindications and complications of the therapy, and the principles of NCPAP titration.
Clear, written protocols for identifying obstructive respiratory events appropriate for therapy intervention must exist along with protocols describing the goals and techniques for optimal NCPAP titration. In addition factors which may affect the patient's ability to use the therapy must be identified and addressed. The physiologic effects of NCPAP intervention must by understood by the technologist and recognition of polysomnographic (PSG) signs and symptoms of physiologic and behavioral intolerance of NCPAP are essential to successful titration.
The goal of optimal NCPAP therapy is to eliminate all obstructive respiratory events and arousals in all positions and in all sleep stages. Documentation of specific criteria applied for each increase in pressure is important an serves as an excellent educational tool during chart reviews. In general the following steps will lead to successful titration of NCPAP in the uncomplicated patient.
1. Increase pressure 2 cmH20 when obstructive events or cyclic arousals are observed.
Rate of increase varies with patients response, the goal is to reach t he titrated pressure as soon as possible to facilitate step 2.
2. Observe patient in all sleep stages with emphasis on supine position during REM.
Intervene to request position change to supine if necessary.
3. Identify and respond appropriately to non-cyclic arousals and other indications of intolerance.
4. Identify and respond appropriately to central apneas, hypoventilation, decreased respiratory rate induced by the effects of NCPAP on the patient's ventilatory drive.
5. Recognize polysomnographic markers of unsuccessful NCPAP titration, and select appropriate additional or optional therapies, ie oxygen, bi-level ventilation.
6. Wake up the patient from REM at the conclusion of the study if possible.
THE BEST CPAP OR BI-LEVEL TITRATION IS ACCOMPLISHED IN VAIN IF THE PATIENT IS NOT COMPLIANT!! Non compliance is the number one reason for NCPAP failure. As patients are evaluated and treated is shorter and shorter time frames with less and less interaction with highly trained polysomnographic technologists, our greatest challenge may not be an optimal titration but patient education and follow-up to assure compliance with the therapy. We must also be actively involved in assessing the efficacy of self adjusting units since the literature is currently conflicting. (Rattenborg, Sleep Research 1996; Johnson, Sleep Research 1996)