Wednesday, December 3, 2014
Canadian Health Care Mall: Patients With SDB
Perhaps the best way to examine the role of NR in patients with SDB is to reduce the resistance and examine the effect on sleep and breathing. This has been done in a variety of ways. Mechanical nasal dilators are marketed to relieve snoring, and have been shown to have a similar effect on NR as measured by active posterior rhinometry as a topical decongestant.
Their effect on snorers without significant nasal pathology is unclear, as some studies failed to demonstrate changes in SDB events or arterial oxygen saturation levels, while others showed improvement in sleep quality, ease of breathing, and a decreased intensity of snoring. In patients with OSAS, one study showed that only 4 of 21 patients with moderate-to-severe OSAS had a significant reduction in SDB events, while another study showed no significant change in SDB events in a group of patients with UARS.
It appears that the overall effect on SDB with mechanical nasal dilators is likely small and inconsistent. Dental prostheses have been used to treat all forms of SDB. These devices keep the upper and lower jaws opposed during sleep and advance the mandible forward. This prevents posterior movement of the mandible during sleep and increases nasal breathing. When evaluated in a group of snoring patients without symptoms of OSAS, one type of prosthesis did not alter the frequency or intensity of snoring or sleep quality or oxygen saturation despite decreasing SDB events; from this one small study, it does not appear dental prostheses improve SDB by any effect on the nasal airway.
Reducing NR by surgical correction of nasopha-ryngeal anatomic obstruction has been examined by a number of investigators. Surgical approaches have included correction of the nasal valve area, septoplasty, and turbinate reduction. Only one small study examined the effect of correction of nasal valve obstruction, showing both subjective and objective improvement in snoring and daytime somnolence. Two uncontrolled studies in patients with nasal obstruction showed that septoplasty or turbinate reduction had some positive effects on SDB.
In one study, 77% (47 of 113 patients) who snored had improvement or elimination of snoring postoperatively. The second study involved patients with mild OSAS where cephalometrics were performed preoperatively; patients with abnormal cephalomet-rics, implying a skeletal anatomic defect, did not respond to improvement of their nasal airway. In a study of a diverse group of adults and children with SDB, who had a variety of surgical procedures , significant improvement occurred in only 48% of adults.