Sleep apnoea and hypertension: proof at last?
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Humans↗
Biomedical subjects
J R Stradling
Publications and source records attributed to J R Stradling.
Is more NCPAP better?
STUDY OBJECTIVES: To assess the benefit of NCPAP in OSA and its relation to the degree of use of NCPAP. DESIGN: Randomised parallel controlled one month study comparing NCPAP set at therapeutic levels of pressure, with NCPAP set at sub-therapeutic pressure levels. SETTING: Teaching hospital sleep clinic and laboratory SUBJECTS: 101 men referred for investigation of possible OSA who were sleepy (Epworth Sleepiness Score > or = 10) and had > or = 10/hr of >4% dips in SaO2 due to OSA. OUTCOME MEASURES: Baseline and one month measures of Epworth Sleepiness Score (ESS), Maintenance of Wakefulness Test (MWT), and the Energy/Vitality dimension of the SF-36 (health status questionnaire). Correlation of these outcome measures with NCPAP usage. RESULTS: All outcome measures improved significantly more in the therapeutic, compared to the sub-therapeutic, group (e.g. ESS 15.0 to 13.0 on sub-therapeutic, and 15.5 to 7.0 on therapeutic, p<1x10(-6)). The degree of improvement correlated significantly with NCPAP usage in the therapeutic group (ESS, r=-0.60; MWT, r=0.55) but insignificantly in the sub-therapeutic group (ESS, r=-0.15; MWT, r=-0.06). Sub-therapeutic NCPAP did not improve OSA severity and acted as a control. CONCLUSIONS: NCPAP is clearly effective in relieving the sleepiness of OSA compared to a control group identical in every way, except for receiving a nasal pressure inadequate to control the OSA.
Adult↗
Steering simulation performance in patients with obstructive sleep apnoea and matched control subjects.
Patients with obstructive pulmonary disease (OSA) have an increased rate of driving accidents, perhaps due to poor vigilance or impaired cognitive skills that influence their driving ability. The authors have assessed whether patients with OSA perform differently to control subjects on a steering simulator which allows the separate assessment of the two visual tasks required for steering a car, immediate positioning on road with reference to the road edges, and assessment of the curve of the oncoming road which allows faster driving. Twelve patients with OSA and 12 control subjects, matched for age, sex and driving experience, performed three 30-min drives with either all the oncoming road visible, only the near part of the road visible, or only the distant part of the road visible. Steering was assessed by measuring the SD around the theoretical perfect path (steering error) and the number of times the driver went "off road". Subjects identified the appearance of target numbers at the four corners of the screen as quickly as possible, thus making the test a divided attention task. Patients with OSA performed significantly less well on the three different road fields as measured by steering error (p<0.001), time to detect the target number (p<0.03), and off road events (p<0.03). The patients appeared to be particularly impaired on the two drives when only part of the road ahead was available to guide steering. This steering simulator, with its more realistic view of the road ahead, identifies impaired performance in patients with obstructive sleep apnoea. In addition it suggests that patients with obstructive sleep apnoea may be more disadvantaged compared to normal subjects when the view of the road ahead is limited (such as in fog).
Adult↗
Prevalence of sleepiness and its relation to autonomic evidence of arousals and increased inspiratory effort in a community based population of men and women.
Degrees of sleep apnoea and daytime sleepiness are quite common in community populations. However the relationship between the two is poor, although sleepiness does correlate better with a history of snoring. It has been suggested that sleep can be fragmented by upper airways obstructive events, short of full apnoeas or hypopnoeas, and that these events may not provoke full cortical arousal, but be detectable through activation of the autonomic system. Failure to detect both these could mask a relationship between 'sleep apnoea' and daytime sleepiness. We have therefore measured sleepiness (Epworth Sleepiness Scale) in addition to both autonomic 'arousals' and inspiratory effort (using pulse transit time) in 473 men and women at home. Although sleepiness was related to a history of snoring, it was not significantly predicted by the measures of autonomic 'arousal', or inspiratory effort. Reported snoring and objectively measured snoring correlated poorly. As in other studies, nocturnal hypoxic dips were correlated with obesity, age, alcohol consumption, drug usage and a history of snoring. These data make it unlikely that sleep fragmentation from subtle variants of sleep apnoea and 'autonomic' (or 'subcortical') arousals are an important source of daytime sleepiness in the community.
Arousal↗
Which derivative from overnight oximetry best predicts symptomatic response to nasal continuous positive airway pressure in patients with obstructive sleep apnoea?
The cost and inconvenience of polysomnography for the investigation of obstructive sleep apnoea (OSA) has led to the search for simpler and cheaper alternatives. These are usually compared to an apnoea/hypopnoea index (AHI) derived from oro-nasal airflow and ribcage/abdominal effort sensors. However, AHI is not a proven gold standard for the identification of clinically important OSA. Recent work has shown that correctly analysed oximetry indices not only mimic AHI with considerable accuracy, but also predict the symptomatic response to nasal continuous positive airway pressure (nCPAP) at least as well as conventional polysomnographic indices. This current study looks at 10 different derivatives of all-night oximeter tracings in 81 patients with OSA, and compares their ability to predict the improvement in subjective sleepiness after 6 months of nCPAP therapy. Sleep apnoea in this study was defined as a > 4% SaO2 dip rate of > 10 h(-1), and an Epworth sleepiness score (ESS) of > 10 on presentation. Subjects took part in a placebo-controlled trial of nCPAP for 1 month and thereafter were all supplied with nCPAP set at an effective pressure. All night SaO2 was sampled every 2 sec and later analysed for mean, median, mean nadir of SaO2 dip, time below 90%, 2 and 12 sec delta index (an average measure of SaO2 change across these two time periods), rapid resaturation index (rises in SaO2 > 3% within 10 sec per hour), and > 4, > 3, and > 2% dips per hour. These indices were then correlated with the change in ESS seen after 6 months on nCPAP. Median compliance for the group was 5.8 (5/95% range, 1.5-8.0) h night(-1). The two best correlates of improvement in ESS were the > 4% SaO2 dips h(-1) (Spearman's r = -0.33 P=0.002) and the delta 12 sec index (r = -0.33, P = 0.003). Cumulative time below 90% SaO2 was almost as good (r = -0.29, P = 0.009). The worst correlate was the > 2% SaO2 dips h(-1) (r = 0.01, not significant). This study has identified which of several analyses of overnight oximeter recordings best identify nCPAP responsive OSA. Both > 4% SaO2 dips and 12 sec delta index are equally predictive and presumably the most appropriate derivatives to calculate from overnight records of SaO2.
Adult↗
Randomised prospective parallel trial of therapeutic versus subtherapeutic nasal continuous positive airway pressure on simulated steering performance in patients with obstructive sleep apnoea.
BACKGROUND: Obstructive sleep apnoea (OSA) impairs vigilance and may lead to an increased rate of driving accidents. In uncontrolled studies accident rates and simulated steering performance improve following treatment with nasal continuous positive airway pressure (NCPAP). This study seeks to confirm the improvement in steering performance in a randomised controlled trial using subtherapeutic NCPAP as a control treatment. METHODS: Fifty nine men with OSA (Epworth Sleepiness Score (ESS) of > or =10, and > or =10/h dips in SaO(2) of >4% due to OSA) received therapeutic or subtherapeutic NCPAP ( approximately 1 cm H(2)O) for one month. Simulated steering performance over three 30-minute "drives" was quantified as: standard deviation (SD) of road position, deterioration in SD across the drive, length of drive before "crashing", and number of off-road events. The reaction times to peripheral target stimuli during the drive were also measured. RESULTS: Subtherapeutic NCPAP did not improve overnight >4% SaO(2) dips/h compared with baseline values, thus acting as a control. The SD of the steering position improved from 0.36 to 0.21 on therapeutic NCPAP, and from 0.35 to 0.30 on subtherapeutic NCPAP (p = 0.03). Deterioration in SD of the steering position improved from 0.18 to 0.06 SD/h with therapeutic NCPAP and worsened from 0.18 to 0.24 with subtherapeutic NCPAP (p = 0.04). The reaction time to target stimuli was quicker after therapeutic than after subtherapeutic NCPAP (2.3 versus 2.7 seconds, p = 0.04). CONCLUSIONS: Therapeutic NCPAP improves steering performance and reaction time to target stimuli in patients with OSA, lending further support to the hypothesis that OSA impairs driving, increases driving accident rates, and that these improve following treatment with NCPAP.
Accidents, Traffic↗
Which aspects of breathing during sleep influence the overnight fall of blood pressure in a community population?
BACKGROUND: Obstructive sleep apnoea (OSA) causes recurrent rises in blood pressure during sleep, and recent community surveys have suggested a link between mild OSA and diurnal hypertension. The fact that OSA and hypertension share some risk factors, as well as problems accurately quantifying OSA severity, have diluted the power of such studies. This study tries to circumvent some of these problems by measuring the overnight change in blood pressure and relating it to relevant measures of the severity of upper airway obstruction on the same night. METHODS: Men born between 1930 and 1960 and their wives living in a market town north of Oxford were identified from a GP practice register. Enough couples were recruited to provide approximately 10 (20 individuals) per year of birth. Subjects were visited at home where a questionnaire was administered, anthropometric measurements made, blood pressures taken (including by the subject), and sensors applied for a subsequent overnight sleep study. The sleep study measured indices of hypoxia, snoring, autonomic arousal, degree of respiratory effort; the last two of these derived from measurements of pulse transit time (indirect beat to beat blood pressure). After waking the following morning, the subjects took their own blood pressures again. RESULTS: Data were available from 224 couples (448 subjects). On average, systolic BP fell 8 mm Hg from evening to morning. Only hypoxic dips (>4% SaO(2) dips/h) and the measure of degree of respiratory effort were significant independent predictors of this overnight change in systolic BP, together accounting for 7-10% of the variation (p<0.0001). Dividing the subjects into quartiles according to the respiratory effort overnight showed a progressive reduction in the fall of systolic BP overnight: 13.6, 10.8, 7.3, and 5.6 mm Hg, lowest to highest quartiles. CONCLUSIONS: This study suggests that increased respiratory effort during sleep (seen in OSA and related syndromes of increased upper airway resistance during sleep) offsets the normal fall in BP that occurs overnight, even within this community population. This may be one of the mechanisms by which hypertension is carried over into the waking hours in patients with OSA.
Adult↗
Case-control study of 24 hour ambulatory blood pressure in patients with obstructive sleep apnoea and normal matched control subjects.
BACKGROUND: There is considerable debate regarding the relationship between obstructive sleep apnoea (OSA) and hypertension. It is unclear whether OSA is an independent vascular risk factor as studies attempting to assess this association have produced conflicting results because of confounding variables such as upper body obesity, alcohol, and smoking. A case-control study of 24 hour ambulatory blood pressure was undertaken in patients with OSA and matched controls to assess whether OSA is an independent correlate of diurnal hypertension. METHODS: Forty five patients with moderate to severe OSA and excessive daytime sleepiness were matched with 45 controls without OSA in a sleep study. Matched variables included age, body mass index (BMI), alcohol, cigarette usage, treated hypertension, and ischaemic heart disease. Upper body obesity was compared by waist:hip and waist:height ratios; 24 hour ambulatory blood pressure recordings were performed (before treatment for OSA) in all subjects. RESULTS: Patients with OSA had significantly increased mean (SD) diastolic blood pressure (mm Hg) during both daytime (87.4 (10.2) versus 82.8 (9.1); p=0.03, mean difference 4.6 (95% CI 0.7 to 8.6) and night time (78.6 (9.3) versus 71.4 (8.0); p<0.001, mean difference 7.2 (95% CI 3.7 to 10.6)), and higher systolic blood pressure at night (119.4 (20.7) versus 110.2 (13.9); p=0.01, mean difference 9.2 (95% CI 2.3 to 16.1)). The nocturnal reduction in blood pressure ("dipping") was smaller in patients with OSA than in control subjects. CONCLUSIONS: Compared with closely matched control subjects, patients with OSA have increased ambulatory diastolic blood pressure during both day and night, and increased systolic blood pressure at night. The magnitude of these differences is sufficient to carry an increased risk of cardiovascular morbidity. The slight excess of upper body fat deposition in the controls may make these results conservative.
Adult↗
The efficacy of nasal continuous positive airway pressure in the treatment of obstructive sleep apnea syndrome is proven.
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Humans↗
Efficacy and safety of a novel beclomethasone dipropionate dry powder inhaler (Clickhaler) for the treatment of adult asthma. Amsterdam Clinical Study Group.
A randomized, double-blind, double-dummy protocol was used to compare the safety and efficacy of beclomethasone dipropionate (BDP) delivered by a novel dry powder inhaler (DPI, Clickhaler) or by a pressurized metered-dose inhaler (MDI) plus spacer. There was a four-week run-in period, completed by 240 adult patients, who received BDP via an MDI. Patients with stable asthma were then randomized into a 12-week treatment period and received BDP (< or =2 mg/day via DPI or MDI). There were no significant differences in morning peak expiratory flow (PEF) (primary endpoint), evening PEF, overall daytime or nighttime symptom scores, or lung function parameters (forced expiratory volume in 1 sec, forced vital capacity) between DPI and MDI. The safety profiles were similar and patient acceptability for Clickhaler was high. In conclusion, BDP administered via Clickhaler was found to be clinically equivalent to an optimally used MDI. Patients with stable asthma currently receiving BDP via MDI may be effectively switched to treatment via Clickhaler DPI.
Anti-Asthmatic Agents↗
Comparison of therapeutic and subtherapeutic nasal continuous positive airway pressure for obstructive sleep apnoea: a randomised prospective parallel trial.
BACKGROUND: Nasal continuous positive airway pressure (NCPAP) is widely used as a treatment for obstructive sleep apnoea. However, to date there are no randomised controlled trials of this therapy against a well-matched control. We undertook a randomised prospective parallel trial of therapeutic NCPAP for obstructive sleep apnoea compared with a control group on subtherapeutic NCPAP. METHODS: Men with obstructive sleep apnoea, defined as an Epworth sleepiness score of 10 or more and ten or more dips per h of more than 4% SaO2 caused by obstructive sleep apnoea on overnight sleep study, were randomly assigned therapeutic NCPAP or subtherapeutic NCPAP (about 1 cm H2O) for 1 month. Primary outcomes were subjective sleepiness (Epworth sleepiness score), objective sleepiness (maintenance of wakefulness test), and SF-36 questionnaire measurements of self-reported functioning and well-being. FINDINGS: 107 men entered the study: 53 received subtherapeutic NCPAP and 54 therapeutic NCPAP. Use of NCPAP by the two treatment groups was similar: 5.4 h (therapeutic) and 4.6 h (subtherapeutic) per night. Subtherapeutic NCPAP did not alter the overnight number of SaO2 dips per h compared with baseline, and thus acted as a control. Therapeutic NCPAP was superior to subtherapeutic NCPAP in all primary outcome measures. The Epworth score was decreased from a median of 15.5 to 7.0 on therapeutic NCPAP, and from 15.0 to 13.0 on subtherapeutic NCPAP (between treatments, p<0.0001). Mean maintenance-of-wakefulness time increased from 22.5 to 32.9 min on therapeutic NCPAP and, not significantly, from 20.0 to 23.5 min on subtherapeutic NCPAP (between treatments p<0.005). Effect sizes for SF-36 measures of energy and vitality were 1.68 (therapeutic) and 0.97 (subtherapeutic) NCPAP (between treatments p<0.0001). For mental summary score, the corresponding values were 1.02 and 0.4 (between treatments p=0.002). INTERPRETATION: Therapeutic NCPAP reduces excessive daytime sleepiness and improves self-reported health status compared with a subtherapeutic control. Compared with controls, the effects of therapeutic NCPAP are large and confirm previous uncontrolled clinical observations and the results of controlled trials that used an oral placebo.
Adult↗
Second by second patterns in cortical electroencephalograph and systolic blood pressure during Cheyne-Stokes.
Little is known about how arousal develops during the ventilatory phase of Cheyne-Stokes breathing. This study employs neural network analysis of electroencephalograms (EEGs) to describe these changes and relate them to changes in systolic blood pressure, which is probably a subcortical marker of arousal. Six patients with Cheyne-Stokes respiration (apnoea/hypopnoea index 32-69 h(-1)) caused by stable chronic heart failure underwent polysomnography including arterial beat-to-beat systolic blood pressure determination. Periods of 15 sequential apnoeas during nonrapid eye movement sleep were identified for each subject. For each apnoea, the EEG was examined second-by-second using neural net analysis from 28 s before to 28 s after apnoea termination (first return of oronasal airflow), and this was compared with the systolic blood pressure pattern. During the apnoeic phase, sleep deepened progressively. Arousal started to develop at or just before apnoea termination and progresses through the breathing phase. The rise and fall in the systolic blood pressure closely followed the rise and fall in electroencephalographic sleep depth. In conclusion, during Cheyne-Stokes breathing, cortical electroencephalographic arousal begins at or just before the resumption of breathing. Cortical electroencephalographic sleep depth changes are closely mirrored by changes in arterial systolic blood pressure, suggesting that the state changes in the cortical and basal brain structures may be synchronous.
Arousal↗
Variation in the arousal pattern after obstructive events in obstructive sleep apnea.
The relationship between the severity of obstructive sleep apnea (OSA) (measured by sleep study) and daytime sleepiness is poor. Variation in the degree of arousal accompanying obstructive respiratory events might help explain this poor correlation. Polysomnographic records from patients with OSA were reviewed in order to extract representative examples of apneas and hypopneas (in 10 patients), as well as events both supine and decubitus (in 12 patients). The EEG accompanying each obstructive event was processed with a neural network technique to describe sleep depth on a second-by-second basis. The lengths of any visually evident microarousals were also measured manually. There was considerable interindividual variation in the degree of sleep disturbance using the neural network technique (p < 0.005), but not using the lengths of the visually scored microarousals (p = 0.6). The arousals accompanying apneic events caused greater variability in sleep depth quantified using the neural network technique (p = 0.03), and also lasted longer based on the visual scoring (mean, 12.6; SD, 1.7 s) than the hypopneic events (mean, 9.9; SD, 2.4 s; p = 0.02). There were no significant differences between events occurring supine versus decubitus with either technique (p = 0.7). These differences in arousal magnitude may explain some of the poor correlations between conventional measures of sleep apnea severity and daytime sleepiness.
Arousal↗
Health status in obstructive sleep apnea: relationship with sleep fragmentation and daytine sleepiness, and effects of continuous positive airway pressure treatment.
Patients with obstructive sleep apnea (OSA) have impaired health status that improves with nasal continuous positive airway pressure (nCPAP). The study reported here explored the relationships between health status, its improvement with nCPAP, sleep fragmentation, and daytime sleepiness. In the study, 51 patients (46 male, five female) ranging from nonsnorers to individuals with severe OSA (median apnea/hypopnea index [AHI] 25, 90% central range: 1 to 98) had polysomnography with microarousal scoring, respiratory arousal scoring, and measurement of pulse transit time. The Short Form-36 Health Survey (SF-36) questionnaire was administered before and after 4 wk of nCPAP treatment; daytime sleepiness was also measured before starting nCPAP. Relationships between pretreatment health status and sleep fragmentation were weak, but significant associations were found between all sleep fragmentation indices and health status improvement with nCPAP (e.g., arousals according to the criteria of the American Sleep Disorders Association versus change in the physical component summary, r = 0.44, p < 0.001). Compared with general population data, the dimensions of energy and vitality and physical role limitation were abnormal before nCPAP (p < 0.05) and normalized with treatment. Sleepiness and pretreatment SF-36 values correlated significantly (Epworth Sleepiness Scale versus energy and vitality, r = -0.47, p < 0.001; modified Maintenance of Wakefulness Test versus energy and vitality, r = 0.32, p < 0.05). We conclude that the health status of patients with OSA improves with nCPAP and this improvement correlates with sleep fragmentation severity. However, the correlation is not very close, which may reflect the improvement with nCPAP of other symptoms not directly related to disease severity.
Adult↗
Autonomic markers of arousal during sleep in patients undergoing investigation for obstructive sleep apnoea, their relationship to EEG arousals, respiratory events and subjective sleepiness.
Estimating the degree of sleep fragmentation is an important part of a respiratory sleep study and is conventionally measured using EEG micro arousals or is inferred indirectly from respiratory abnormalities such as apnoeas and desaturations. There is a need for less labour-intensive measures of sleep fragmentation, and transient rises in blood pressure and heart rate may fulfil this role. Forty unselected sleep clinic referrals undergoing investigation for possible obstructive sleep apnoea (OSA) were studied with one night of polysomnography. Three conventional indices of sleep fragmentation (EEG micro arousals, apnoea/hypopnoea index (AHI) and oxygen saturation dip rate (SaO2 dips)) and two autonomic indices (heart rate and blood pressure rises) have been compared. Correlations between these five indices ranged from r=0.38 to r=0.73. Of the two autonomic indices, the correlations for blood pressure rises with SaO2 dips and EEG micro arousals were stronger (r=0.71 and r=0.65, respectively) than those for heart rate rises (0.55 and 0.51). All indices of sleep fragmentation, apart from heart rate rises, were similar in their correlation with subjective sleepiness (r-values 0.21-0.36). Arousals implied from blood pressure rises (using pulse transit time) can be measured easily, are objective, and appear no worse at predicting subjective sleepiness than either EEG micro arousals or AHI. They may therefore provide a useful alternative to manual scoring of micro arousals from the EEG as an index of sleep fragmentation in sleep clinic patients undergoing investigation for possible OSA.
Adult↗
Oral appliances for the management of snoring and obstructive sleep apnoea.
BACKGROUND: Although oral appliances are effective in some patients with obstructive sleep apnoea (OSA), they are not universally effective. A novel anterior mandibular positioner (AMP) has been developed with an adjustable hinge that allows progressive advancement of the mandible. The objective of this prospective crossover study was to compare efficacy, side effects, patient compliance, and preference between AMP and nasal continuous positive airway pressure (nCPAP) in patients with symptomatic mild to moderate OSA. METHODS: Twenty four patients of mean (SD) age 44.0 (10.6) years were recruited with a mean (SD) body mass index of 32.0 (8.2) kg/m2, Epworth sleepiness score 10.7 (3.4), and apnoea/hypopnoea index 26.8 (11.9)/hour. There was a two week wash-in and a two week wash-out period and two treatment periods (AMP and nCPAP) each of four months. Efficacy, side effects, compliance, and preference were evaluated by a questionnaire and home sleep monitoring. RESULTS: One patient dropped out early in the study and three refused to cross over so treatment results are presented on the remaining 20 patients. The apnoea/hypopnoea index (AHI) was lower with nasal CPAP 4.2 (2.2)/hour than with the AMP 13.6 (14.5)/hour (p < 0.01). Eleven of the 20 patients (55%) who used the AMP were treatment successes (reduction of AHI to < 10/hour and relief of symptoms), one (5%) was a compliance failure (unable or unwilling to use the treatment), and eight (40%) were treatment failures (failure to reduce AHI to < 10/hour and/or failure to relieve symptoms). Fourteen of the 20 patients (70%) who used nCPAP were treatment successes, six (30%) were compliance failures, and there were no treatment failures. There was greater patient satisfaction with the AMP (p < 0.01) than with nCPAP but no difference in reported side effects or compliance. CONCLUSIONS: AMP is an effective treatment in some patients with mild to moderate OSA and is associated with greater patient satisfaction than nCPAP.
Humans↗
Sleep fragmentation indices as predictors of daytime sleepiness and nCPAP response in obstructive sleep apnea.
Sleep fragmentation and respiratory disturbance measures are used in the assessment of obstructive sleep apnea (OSA) but have proved to be disappointingly poor correlates of daytime sleepiness. This study investigates the ability of electroencephalograph (EEG) and non-EEG sleep fragmentation indices to predict both presenting sleepiness and the improvement in sleepiness with subsequent nasal continuous positive airway pressure (nCPAP) therapy (nCPAP responsive sleepiness). Forty-one patients (36 men, 5 women), ranging from nonsnorers to severe OSA (> 4% O2 dip rate, median 11.1, range 0.4 to 76.5), had polysomnography with microarousal scoring, computerized EEG analysis, autonomic arousal detection, and body movement analysis. All patients received a trial of nCPAP regardless of sleep study outcome. Spearman's correlation analysis showed significant and similar associations between all sleep fragmentation indices with both pretreatment and nCPAP responsive sleepiness. There was no deterioration in sleepiness on nCPAP in the nonsnorers. Using stepwise multiple regression analysis, the best predictor of nCPAP responsive subjective and objective sleepiness was body movement index, explaining 38% and 43% of the variance, respectively. Variability in EEG sleep depth, quantified from computerized EEG analysis, was the only other index to contribute to these models. Together these indices explained 44% and 51% of the subjective and objective response to nCPAP, respectively. These results suggest that sleep fragmentation indices are useful for identifying OSA patients with sleepiness likely to respond to nCPAP.
Adult↗
Mandibular advancement devices for the control of snoring.
Patients presenting with the complaint of antisocial snoring have very few options available to them of proven efficiency. Mandibular advancement devices worn intra-orally at night, have recently been shown in controlled trials to help mild to moderate obstructive sleep apnoea. However, there are no properly controlled studies with objective measurements on the use of such appliances for the management of antisocial snoring. Fifteen patients, already established on mandibular advancement devices for the control of snoring, were asked to participate in this study. They were studied over two nights, using a portable sleep monitoring device at home, both with and without their mandibular advancement devices in place (in randomized order). Snoring was measured using a surface throat microphone. In addition oxygen saturation and indirect beat to beat blood pressure were measured. The latter (using pulse transit time) provided an index of autonomic "arousals" and a measure of inspiratory effort. In nearly all of these highly selected patients the mandibular advancement devices reduced significantly the amount of snoring from a median of 193 to 20 snores x h(-1) (p<0.0001). In addition there was a reduction in respiratory effort, implying enlargement of the upper airway whilst wearing the appliance. These patients only represent those who were able to tolerate the appliance. With such clear evidence of their potential efficacy, and no suggestion from other studies of any harm, it would seem reasonable to introduce this approach into the management of antisocial snoring.
Adult↗