Therapeutic use of auto-CPAP.
Auto-CPAP is a new technology by which a continuous positive airway pressure (CPAP) device automatically adjusts the level of mask pressure to the patient's requirements. It has been proposed with two different goals: (1) to improve treatment and (2) to perform automatic titration. The improvement of treatment involves two aspects: (a) improving treatment efficacy and (b) improving compliance with treatment. The rationale behind better treatment efficacy is that the patients' requirements vary over both the short and long term. However, there are few data in the literature showing that this is true, let alone concerning its importance and impact. Published studies fail to demonstrate better treatment efficacy with auto-CPAP compared with manually titrated conventional CPAP. The rationale behind improved compliance with treatment is that auto-CPAP should achieve the same treatment efficacy with lower nasal pressures, and thus reduce side effects and improve compliance. Again, the postulate that higher nasal pressures cause lower compliance is not supported. Published studies show variable results both on the level of pressure delivered with an auto-CPAP device (as compared with the optimal pressure used with conventional fixed pressure, but this probably depends on the definition of optimal fixed pressure) and on observed compliance with auto-CPAP. The main problem here is that most studies were not double-blinded which is critical as the end-point (i.e., patient compliance), heavily depends on the relationship between the medical staff and the patient. The aim of titration with auto-CPAP is to save on costs, as patients are treated with fixed conventional CPAP once the titration procedure is accomplished. Auto-titration can be performed either in the sleep laboratory (then the auto-titrating devices can be sophisticated and cumbersome) or in the patients' home. Published studies suggest that auto-titration can be accurately performed, but given the additional cost of the device, the necessity of supervision (albeit a less qualified supervision than with manual titration) and the failure rate, the cost-effectiveness of auto-titration remains to be established.
Sleep Disorders Unit, Service d'Explorations Fonctionnelles du Système Nerveux et de Pathologie du Sommeil, Hôpitaux Universitaires de Strasbourg, Strasbourg, France. Jean.Krieger@chru-strasbourg.fr
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