Arousability in sleep apnoea/hypopnoea syndrome patients.

Sleep disruption and daytime sleepiness in obstructive sleep apnoea/hypopnoea syndrome (OSAHS) patients result from recurrent apnoeas/hypopnoeas and arousals from sleep. Around 30% of apnoeas/hypopnoeas are not terminated by visible cortical arousals. The current authors tested the hypotheses that arousal induction is linked to sleep stage, oxygen desaturation, event type, event duration and time of occurrence during the night. Fifteen patients with OSAHS of varying severity were studied and all their apnoeas/hypopnoeas were evaluated. Eight of 15 patients had apnoeas/hypopnoeas in all sleep stages, and all their 610 apnoeas/hypopnoeas were analysed in the between stages comparison; data from all 15 patients were included in other comparisons. Thirty-four per cent of apnoeas/hypopnoeas during slow wave sleep (SWS) were associated with arousal, significantly less than the 77% during nonrapid eye movement (NREM) 1 and 2 and 62% during rapid eye movement (REM) sleep. Arousal induction was not affected by oxygen desaturation, event type, duration or time of the night. The apnoeal/hypopnoea index was 39 x h(-1) in REM 1 and 2, significantly higher compared to 17 x h(-1) in REM or to 11 x h(-1) in SWS sleep. In conclusion, apnoeas/hypopnoeas in slow wave sleep are associated with fewer cortically apparent, visually detected arousals.

Sleep apnea syndrome in patients with cardiac pacemaker.

BACKGROUND: Heart rhythm disturbances are cardiac side effects in patients with sleep-disordered breathing (SDB), which in itself is considered to be a risk factor for bradycardic rhythm disturbances. OBJECTIVE: We analyzed the prevalence and degree of SDB in patients who received a cardiac pacemaker due to bradycardic rhythm disturbances and investigated the relationship between the severity of an underlying SDB and the type of heart rhythm disturbance. METHODS AND RESULTS: 192 patients (100 males, 92 females, mean age 62.2 +/-12.2 years) were studied using the portable screening device MESAM IV. The respiratory disturbance index (RDI) was calculated visually. The mean RDI in all patients was 9.13+/-11. 09/h, 11.7+/-13.15/h in males and 6.33+/-7.42/h in females. The prevalence ratio of SDB between men and women was 1.7:1, with significant differences in the respective severity (p<0.05). The screening showed a prevalence of SDB (RDI >10/h) of 32.3%. The highest prevalence was found in the group of patients with atrial fibrillation and bradycardia. However, there were no significant differences compared to other types of rhythm disturbances. The RDI in the population studied depended on age and body mass index, but not on the existence or type of rhythm disturbance and not on concomitant diseases. CONCLUSION: The prevalence of SDB in cardiac pacemaker patients is similar to that in patients of comparable age without a pacemaker. A heart rhythm disturbance does not seem to be an independent risk factor for development of SDB. Nevertheless, the differential diagnosis of bradycardic rhythm disturbances in this age group should include a screening for sleep apnea.

Respiratory arousals in mild obstructive sleep apnea syndrome.

The objective of the study is to identify patients with mild sleep apnea by counting not only apneas and hypopneas, but also mild respiratory events, which do not fulfill apnea or hypopnea criteria, but result in an arousal (Type-R arousal). Arousals related to body movements (Type-M arousal) were separately counted. The influence of nasal continuous positive airway pressure (nCPAP) on respiratory and movement arousals was analyzed. Daytime sleepiness before and after nCPAP and its relationship to arousal types was investigated using the Multiple Sleep Latency Test (MSLT) and a standardised questionnaire. Twenty-two patients with a mean age of 43.6 +/- 9.2 years underwent polysomnographic evaluation on a baseline night, and during three nights with nCPAP. On the baseline night, subjects presented with a mean RDI of 10.5 +/- 7.2/h, an apnea index (AI) of 1.2 +/- 1.5/h, a hypopnea index (HI) of 9.3 +/- 6.6/h, a R index of 5.2 +/- 5.9/h, and a M index of 9.7 +/- 5.6/h. Use of nCPAP lowered the RDI (p < 0.001) and the R index (p < 0.01). Mean sleep latency in the MSLT increased with nCPAP (p < 0.05) and the patient's subjective well being improved (p < 0.01). Correlation analysis revealed a relationship between Type-R arousals and RDI and HI (r = 0.5, p < 0.01) as well as between questionnaire scores and mean sleep latency. The decrease of Type-R indicates the positive effect of nCPAP. Arousal analysis and detection of mild respiratory events associated with arousals are helpful in investigating the sleep structure and in objectifying clinical symptoms and treatment success in patients with mild OSAS.

[Multiple sleep latency test in patients with obstructive snoring]. / Der Multiple Schlaflatenz Test bei Patienten mit obstruktivem Schnarchen.

The objective of our study was to examine the effect of the n-CPAP on day tiredness of patients suffering from obstructive snoring. This effect was objectified by means of the Multiple Sleep Latency Test (MSLT). The MSLT was performed with optimal pressure at 8.00, 10.00, 12.00 and 14.00 hrs. subsequent to the control night and the third CPAP night. The latencies of falling asleep and the sleep stages were determined in accordance with the criteria of Rechtschaffen and Kales. The average latency of falling asleep before therapy was: at 8.00 hrs 9.0 +/- 14.2 min, at 14.00 hrs. 7.2 +/- 6.3 min. The following latencies of falling asleep were observed after the third CPAP night: 8.00 hrs. 14.2 +/- 6.3, 10.00 hrs. 13.4 +/- 6.4, 12.00 hrs. 13.7 +/- 6.4 hrs. 13.7 +/- 6.0 min. This means that after the therapy there was a marked tendency to longer latencies at all 4 points of measurement with significant differences at 12.00 and 14.00 hrs. A comparison of the quality of sleep before and after the therapy yielded an increase in deep sleep and a significant increase in REM density during dream sleep. MSLT enabled objectivation of improved sleep quality and of subjective decrease in day tiredness after CPAP therapy in patients with obstructive snoring. The latency in falling asleep increased at all the points of measurement. Nevertheless, interindividual differences are great, compared with the uniform subjective success of CPAP therapy achieved with these patients.

Arousals and sleep stages in patients with obstructive sleep apnoea syndrome: Changes under nCPAP treatment.

Nocturnal arousals are the essential cause of disturbed sleep structure in patients with obstructive sleep apnoea syndrome (OSAS). The aim of this study was to analyse the relationship between sleep stages, respiratory (type-R) and movement (type-M) related EEG arousals. Furthermore, the value of these arousals as a criterion for the efficiency of nCPAP treatment was estimated. We examined 38 male patients aged between 30 and 71 (49.1 +/- 20.9 SD) y. All patients suffered from OSAS. The mean respiratory disturbance index (RDI) was 47.3 +/- 27.8 per h. Polysomnographic monitoring was carried out on 4 subsequent nights: baseline night, 2 nights of nCPAP titration and nCPAP control night. Sleep was visually scored and EEG arousals were classified into type R and M, depending on whether changes of respiration or movement caused the arousal. The RDI, the R index (type-R/h), the M index (type-M/h) and the R and M indices in different sleep stages were calculated. During the baseline night a deficit of slow wave sleep (SWS) and REM sleep was found. Furthermore there were more type-R than type-M arousals registered (17.4 h-1 [3.6-43.6] vs. 5.9 h-1 [1.6-11.8]) (P < 0.01). They occurred during stages NREM 1, NREM 2 and REM (P < 0.01). An SWS sleep rebound and a reduction of the SWS and REM latencies were already found during the first CPAP night. The R index was reduced during the first CPAP night in all sleep stages (P < 0.01) and remained approximately the same in the following 2 nights (3. CPAP night: 1.1 h-1 [0.3-5.0]). Type M arousals occurred more in stages 1 and 2 (P < 0.01), and remained unchanged under nCPAP. We concluded that differentiation of nocturnal arousals may provide more detailed information regarding the influence of breathing disturbances on sleep. Respiratory related, not movement related, arousals may be a useful additional tool in judging the efficiency of OSAS.

[Therapeutic consequences of obstructive sleep apnea syndrome--results of drug, mechanical and surgical treatment]. / Therapeutische Konsequenzen des obstruktiven Schlafapnoesyndroms--Ergebnisse medikamentöser, mechanischer und chirurgischer Behandlung.

The therapeutical strategy of the obstructive sleep apnoea syndrome depends on the differential diagnosis of the sleep disorder, the subjective complaints and the patients' individual cardiopulmonary risk profile. Basic requirements for a successful treatment are stepped concepts for therapy. Initial therapeutical methods are preventive measures such as adequate sleep hygiene, weight loss, and reduction of alcoholic intake. We investigated the effectiveness of following therapeutical methods: drug treatment, nasal CPAP therapy and surgical approach. We present the results of the first 151 treated patients aged between 15 and 88 years (mean: 50.8 +/- 11.5 SD). 20 patients with an apnoea index below 20 per hour were treated with theophylline. After 4 weeks with theophylline there were no significant changes in apnoea index, O2 saturation and snoring level. 24 patients themselves preferred the Uvulopalatopharyngoplasty (UPPP). 8 weeks after surgical approach we couldn't find significant changes in the apnoea index although 11 of these patients reported on a better sleep quality. 107 patients were treated with nasal CPAP. The effective CPAP pressures were between 6 and 14.5 mbar. Long term compliance with CPAP was studied in a survey of 70 patients who underwent a CPAP trial. After 6 months 97% were complaint, 17% of them additionally were using a humidifier. Our data show that effective therapy can be achieved with nCPAP objectively and subjectively. Other methods--theophylline and UPPP--are less successful. CPAP is likely to remain the first choice for treatment of sleep related breathing disorders and it should be applied more generously.

[Diagnostic findings in patients with obstructive sleep apnea syndrome in nCPAP therapy]. / Befunde bei Patienten mit obstruktivem Schlafapnoesyndrom unter nCPAP-Therapie.

The outpatient measurement with the ME-SAM IC system, including the analysis of heart rate, respiration sounds, continuous oxygen saturation and body position, is an important part in a stepped concept for diagnosis and therapy of patients with an obstructive sleep apnea syndrome (OSAS). We investigated the importance of these parameters as well as age and Broca in relation to the continuous positive airway pressure determined in the sleep laboratory. In this study we present the first 60 patients (56 m, 4 f) treated successfully with nCPAP. The mean age was 53.1 +/- 8.6 years, the Broca Index 133.6 +/- 22.9, the respiratory disturbance index (RDI, apnea + hypopnea index) 48.1 +/- 22.7, the mean nocturnal oxygen saturation 90.4 +/- 3.8% and the mean minimal oxygen saturation 84.4 +/- 4.2%. We found positive significant correlation between Broca, RDI and oxygen saturation as well as between Broca and age. The mean effective continuous positive airway pressure was 9.7 +/- 2.1 cm H2O in our group of OSAS patients. With an increase in RDI and with a decrease in age and oxygen saturation we found an significant increase in the effective continuous positive airway pressure. A positive correlation between Broca and air pressure could be seen, but was not significant. Our data show that there is a strong correlation between constitution, the outpatient measurement with MESAM-system and the effective positive airway pressure in patients with a pronounced obstructive sleep apnea syndrome (RDI > 15 and marked clinical symptoms). The knowledge about these relationships should be considered in the nCPAP therapy and during the long term medical care of treated patients.