Effect of surfactant on pharyngeal mechanics in sleeping humans: implications for sleep apnoea.
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Instillation of surfactant into the pharyngeal lumen reduces the pressure required to reopen an occluded airway, and decreases the apnoea/hypopnoea index (AHI). The authors hypothesised that surfactant also reduces the sleep-related increase in pharyngeal resistance. To test this hypothesis two single blind, crossover, placebo-controlled studies were performed. In protocol A seven male, asymptomatic snoring subjects were studied during sleep. Inspiratory pharyngeal resistance was calculated from plots of airflow versus supraglottic pressure (seven breaths) before and after surfactant or saline instillation. In protocol B, in a different group of seven male subjects with sleep apnoea (AHI 15.2 (12) events x h(-1)) the effect of surfactant or saline on sleep disordered breathing was measured, for 1 h immediately before and after surfactant or saline instillation. Surfactant decreased pharyngeal resistance calculated at peak pressure (group mean (SD): pre versus post 83.7 (76.4) versus 49.4 (71.1) cmH2O x L(-1) x s(-1)) and significantly reduced the respiratory disturbance index (RDI pre versus post 79.7 (58.7) versus 59.6 (56.9) events x h(-1)). Saline did not decrease resistance (pre versus post 58.6 (31.1) versus 72.5 (73.4) cmH2O x L(-1) x s(-1)) or RDI (pre versus post 75.3 (42.4) versus 79.9 (46.1) events x h(-1)). Surfactant reduced the collapsibility of the pharynx and led to a modest reduction in respiratory disturbance index. The authors speculate that surfactant may delay occlusion by reducing the liquid "bridging" within the folded pharyngeal lining. (+info)
Dental devices; classification for intraoral devices for snoring and/or obstructive sleep apnea. Final rule.
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The Food and Drug Administration (FDA) is classifying the intraoral devices for snoring and/or obstructive sleep apnea into class II (special controls). These devices are used to control or treat simple snoring and/or obstructive sleep apnea. This classification is based on the recommendations of the Dental Devices Panel (the Panel), and is being taken to establish sufficient regulatory controls that will provide reasonable assurance of the safety and effectiveness of these devices. This action is being taken under the Federal Food, Drug, and Cosmetic Act (the act), as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (the SMDA), and the Food and Drug Administration Modernization Act of 1997 (FDAMA). Elsewhere in this issue of the Federal Register, FDA is publishing a notice of availability of the guidance document that will serve as the special control for this final rule. (+info)
Partitioning of inhaled ventilation between the nasal and oral routes during sleep in normal subjects.
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The oral and nasal contributions to inhaled ventilation were simultaneously quantified during sleep in 10 healthy subjects (5 men, 5 women) aged 43 +/- 5 yr, with normal nasal resistance (mean 2.0 +/- 0.3 cmH(2)O. l(-1). s(-1)) by use of a divided oral and nasal mask. Minute ventilation awake (5.9 +/- 0.3 l/min) was higher than that during sleep (5.2 +/- 0.3 l/min; P < 0.0001), but there was no significant difference in minute ventilation between different sleep stages (P = 0.44): stage 2 5.3 +/- 0.3, slow-wave 5.2 +/- 0.2, and rapid-eye-movement sleep 5.2 +/- 0.2 l/min. The oral fraction of inhaled ventilation during wakefulness (7.6 +/- 4%) was not significantly different from that during sleep (4.3 +/- 2%; mean difference 3.3%, 95% confidence interval -2.1-8.8%, P = 0.19), and no significant difference (P = 0.14) in oral fraction was observed between different sleep stages: stage two 5.1 +/- 2.8, slow-wave 4.2 +/- 1.8, rapid-eye-movement 3.1 +/- 1.7%. Thus the inhaled oral fraction in normal subjects is small and does not change significantly with sleep stage. (+info)
Relationship between sleep apnea hypopnea syndrome and cardiovascular events in elderly Chinese snorers.
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OBJECTIVE: To investigate the relationship between sleep apnea hypopnea syndrome (SAHS) and some cardiovascular abnormalities in elderly snorers, as well as the effectiveness of nasal continuous positive airway pressure on those with SAHS. METHODS: With the use of polysomnography, 73 elderly snorers (older than 60 years) were examined and placed into either the SAHS group or the control group. Using ambulatory electrocardiogram (ECG) and blood pressure measurement, daily nocturnal rhythm of blood pressure, hypertension, heart rate variability, some arrhythmia and angina pectoris of coronary heart disease (CHD) were monitored and compared between the two groups before and after 5 - 7 days of treatment with nasal continuous positive airway pressure on the SAHS group. RESULTS: This study indicated a higher incidence (47.9%) of sleep apnea syndrome in elderly snorers and demonstrated that there was a significantly higher incidence of hypertension, disappearance in daily nocturnal rhythm of blood pressure, poor effectiveness of nitrate on angina pectoris of coronary heart disease, decreased heart rate variability during sleep, increased arrhythmia and lower pulse oxygen saturation (SpO(2)) levels in the SAHS group than in the control group. After nasal continuous positive airway pressure treatment during sleep, snoring control, significantly higher SpO(2) levels and lower index of apnea/hypopnea were achieved in the SAHS group; heart rate variability (HRV) and blood pressure day nocturnal rhythm were returned to normal levels. CONCLUSION: This research suggests that there is a close relationship between the development of sleep apnea syndrome and some cardiovascular diseases. Continuous positive nasal airway pressure is effective not only on SAHS but also on coexisting cardiovascular disorders. (+info)
Bacterial adherence to mucosal epithelium in the upper airways has less significance than believed.
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BACKGROUND: Bacterial adherence to the upper airway epithelium is considered to be an important phenomenon in the pathogenesis of infections. However, the evidence for the hypothesis that bacterial adherence to mucosal epithelial cells has significance for pathogenesis of mucosal infections is based on studies using indirect techniques. We could find no biopsy studies with direct ocular observations of significant numbers of bacteria adhering to upper airway mucosal epithelial cells either in health or during disease. RESULTS: We studied specimens from healthy and infected tonsillar epithelium and specimens from the soft palate epithelium obtained by surgery. The specimens were examined by TEM. In the vast majority of specimens, we found no bacteria adhering to the epithelial cells in the mucosal line regardless of whether the patient was infected or not. Bacteria adhering to shed epithelial cells were seen in higher numbers. Furthermore, as bacteria are small compared to epithelial cells, we calculated the risk of overlooking every adhered bacteria in a section if bacterial adherence was such a significant phenomenon as earlier suggested. We found this risk to be very small. CONCLUSION: We conclude that bacterial adherence to mucosal surface epithelial cells is not a significant phenomenon, either in healthy mucosa in the upper airways or during infection. This is also in line with our earlier results, where we have shown that the site for the infectious process in pharyngotonsillitis is in the secretion on the tonsillar mucosal surface. (+info)
Dental and occlusal changes during mandibular advancement splint therapy in sleep disordered patients.
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The aims of this longitudinal, observational study were two-fold: first, to determine in adults with sleep disorders the extent of dental and occlusal changes following the use of a mandibular advancement splint (MAS) and, second, to determine the time course of these changes. One hundred adult subjects (87 males, 13 females) diagnosed with obstructive sleep apnoea (OSA) and/or asymptomatic snoring were treated with non-adjustable MAS. At the outset each subject was randomly assigned to a group and reviewed 6, 12, 18, 24 or 30 months after placement of a splint. There were 20 subjects in each group. Craniofacial changes were measured on lateral cephalometric radiographs taken at the initial and review appointments. When the changes in all subjects were examined, the SNA, ANB angles, ANS-PNS length and face height increased, and the mandibular first molars and the maxillary first premolars significantly overerupted. Significant retroclination of the maxillary incisors and proclination of the mandibular incisors were accompanied by reductions in maxillary arch length, overbite and overjet. When the changes over time were determined, the mandibular symphysis was significantly lower at all review periods. An increase in face height and reductions in overbite and overjet were evident at 6 months, and over-eruption of the maxillary first premolars and mandibular first molars, and proclination of the lower incisors were found at 24 months. Significant positive correlations were also found between the amount of anterior opening by the appliances and changes in overbite at 24 and 30 months. The appliance used produced small, unpredictable changes in the occlusion that tended to occur after 24 months' wear. It is postulated that the changes in overbite might be lessened by keeping the bite opening to a minimum. (+info)
Validation of measurements of mandibular protrusion in the treatment of obstructive sleep apnoea and snoring with a mandibular protruding device.
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The aims of this study were to compare the maximum range of protrusion determined with a ruler with measurements made using a George Gauge (GG) and to validate the methods of measurement (ruler and GG) of the advancement established by mandibular protruding devices (MPDs), using cephalograms as the gold standard. The study comprised 77 patients (63 males, 14 females, mean age 54 years, range 31-73 years) with obstructive sleep apnoea (OSA) (n = 50) or complaints of snoring (n = 27). After a medical examination that included an overnight somnographic registration and a dental and stomatognathic examination, each patient was given a MPD. Measurements of the maximum range of protrusion with the GG and a ruler were compared. Pairs of upright cephalograms were taken with and without the MPD. The position of the mandible on the cephalograms was compared with ruler measurements of the device-induced protrusion in the incisor and premolar regions, the vertical opening in the anterior region, and GG construction bite registration. The maximum range of protrusion was significantly greater with GG than ruler measurements, on average +1.2 mm (P < 0.001). The mandibular position as measured in the incisor or premolar region with a ruler or on the cephalogram was not significantly different. GG values, however, were higher and differed significantly from ruler and cephalometric measurements (P < 0.001). The degree of anterior mandibular advancement with a MPD measured with a ruler in the incisor or premolar regions compared well with corresponding cephalometric measurements. The ruler and cephalometric measurements of the vertical opening with the MPD coincided well in the incisor region. The GG overestimated the maximum range of protrusion compared with ruler measurements. (+info)
Periodic leg movements during sleep in Japanese community-dwelling adults based on the assessments of their bed partners.
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BACKGROUND: There is little known about epidemiologic evidence on periodic leg movements during sleep (PLMS) for the Japanese. The present study was a cross-sectional epidemiologic study to estimate the prevalence of PLMS and examine the associated factors of PLMS in Japanese community-dwelling adults. METHODS: The subjects were 884 with bed partners or bedroom mates of 1,889 Japanese adults aged 20 years and over randomly selected from the general population. The case ascertainment of PLMS was based on the assessments of their bed partners or bedroom mates using the Pittsburgh Sleep Quality Index. Multiple logistic regression analyses were used for investigating the associated factors. RESULTS: The age-adjusted prevalences (95% confidence interval) were 5.8% (4.7-6.8%) and 1.3% (0.8-1.9%) for 1 to 2-times, and 3-times or greater of PLMS per week during the preceding month, respectively. Those with PLMS were more likely to experience difficulty in initiating sleep, snore during sleep, be depressed, and suffer from peptic ulcer. Sex, age, difficulty in maintaining sleep, excessive daytime sleepiness, medication use to aid sleep, and any psychoactive substances (tobacco, alcohol, and caffeine) were not identified as significant associated factors of PLMS. CONCLUSIONS: The results suggest that the prevalence of PLMS in Japanese community-dwelling adults is not so high as those reported from Western countries, and that PLMS is correlated with some sleep and health disturbances. (+info)