Utilization of polysomnography in the assessment of sleep disorders.

Polysomnography is an indispensable tool in dealing with sleep disorders, but because of its inherent logistical complexity and expense, it must be used with discretion. Many sleep disorders can be diagnosed clinically by the astute physician and treated empirically with good results. On the other hand, there are numerous circumstances in which the best clinical judgment indicates a polysomnographic evaluation. The ubiquity of sleep complaints in medical practice, and the knowledge that they may in some instances be associated with life-threatening medical complications, compel the modern clinician to obtain a basic knowledge of the appropriate utilization of the sleep laboratory. Polysomnography is a useful adjunct to the clinician because it provides objective information to be integrated into the overall clinical picture in the evaluation of the patient's complaint. Polysomnography should be utilized in cases where the results will clearly make a difference in the differential diagnosis or in the treatment plan. If a clinician's basic approach to the evaluation of the patient or his treatment will not be substantially altered by polysomnography, it should not be undertaken. The results of polysomnography should give the referring physician critical information concerning the type of disorder, its severity, appropriate treatment and necessary follow-up. Unfortunately, few, if any, hard and fast rules exist concerning the appropriate utilization of polysomnography. As always in medicine, the physician must take a careful history, and integrate it with other basic laboratory tests and the physical examination, and then decide whether polysomnography will provide useful additional information. The ability to assess physiological phenomena during sleep objectively has clearly advanced the study of sleep disorders to the point that it is now considered an integral part of internal medicine. Polysomnography has made available the objective study and documentation of sleep disorders which, coupled with increasing sophistication concerning the natural history of sleep disorders, have created a new and exciting discipline in clinical medicine.