Nitrazepam in patients with sleep apnoea: a double-blind placebo-controlled study.

We wanted to assess whether benzodiazepines worsen sleep apnoea, since their use in such patients has been controversial. Fourteen male patients with mild to moderate obstructive sleep apnoea were investigated in a placebo-controlled, double-blind study evaluating the influence of nitrazepam (NIT) on apnoea frequency and severity. Each patient was given oral nitrazepam 5 or 10 mg, or corresponding placebo, in a randomized order on three separate nights. Wash-out time was one week. A complete sleep study was undertaken at each study night. Eleven patients completed the study. Although there were individuals with marked variability in apnoea index between the three study nights, there was no significant change in apnoea index or minimum arterial oxygen saturation with any of the two nitrazepam dosages studied. Only 3 out of 11 patients had a higher apnoea index after both nitrazepam doses compared to placebo, and in these patients the increase in sleep-disordered breathing was of marginal clinical significance. Nitrazepam caused a modest increase in total sleep time and a decrease in rapid eye movement (REM) sleep. These results demonstrate that nitrazepam does not worsen sleep apnoea in patients with mild to moderate sleep apnoea. The previously reported sleep apnoea promoting effects of benzodiazepines may be restricted to a small subgroup of patients with sleep-disordered breathing.

The effects of nasal dilation on snoring and obstructive sleep apnea.

The effects of nasal valve dilation on snoring and obstructed breathing were studied in 11 patients with habitual snoring and/or obstructive sleep apnea. The anterior part of the nose, the valve region, was dilated by means of a plastic device. Ten patients underwent polysomnographic investigation including pulse oximetry and measurement of snoring noise with and without the nasal dilator in a randomized manner. Snoring, nocturnal arousals, and daytime hypersomnolence were rated by the patient and partner on a questionnaire before and after a 10-day treatment period with the dilator. The nasal airflow, as assessed by rhinomanometry when awake in the sitting position, increased by 18% (range, 5.5% to 45%) when the nasal dilator was used. The frequency and severity of obstructed breathing decreased significantly with the nasal dilator. The apnea index with and without the nasal dilator was 6.4 (range, 1.3 to 15) and 18 (range, 1.8 to 60), respectively. The mean decrease of the apnea index was 47%. The overnight minimum arterial oxygen saturation (with and without the nasal dilator was 84% (range, 76% to 88%) and 78% (range, 68% to 89%), respectively. There was a substantial decrease in snoring noise (number of epochs with Leq values, equal energy level, above 55 or 60 dB) with the dilator in all patients who presented with snoring noise above these levels during the control night. No subjective effects on arousal frequency or daytime hypersomnolence were reported. Four of 11 patients were positive to continue using the nasal dilator.

Obstructive sleep apnea in patients with pharyngeal tumours.

Six consecutive patients with pharyngeal tumours were investigated regarding disordered breathing during sleep. In addition to pulse oximetry, the investigations involved oral and nasal airflow as well as thoracic respiratory movements in four of the patients in whom the oxygen desaturation index (ODI, number of desaturations per hour of estimated sleep) was on average 24 (range 10-58). An almost total predominance of obstructive apnea was found in evaluated cases. In the 2 cases in whom only pulse oximetry was performed, numerous desaturations were found throughout the night (ODI 19 and 88, respectively). The overnight minimum oxygen saturation before treatment varied but was below 80% in 5 of the 6 patients (range less than 50-89%). On reinvestigation (n = 5) 3-4 months after treatment (radical surgery or, in one case, nasal continuous positive airway pressure (CPAP)), desaturations were totally or almost totally abolished in all patients. It is concluded that the obstructive sleep apnea syndrome may be a common finding in patients with tumours in the pharyngeal region. Radical surgery and/or nasal CPAP may result in complete disappearance of the disordered breathing during sleep in these patients.

The ability of noninvasive methods to detect and quantify laryngeal obstruction.

The ability of the noninvasive methods forced oscillation technique (Rosc), spirometry and flow-volume curves to detect and quantify laryngeal obstruction, using assessment of orolaryngeal (upper) airway resistance (Rol) as reference, was compared in 55 patients with various laryngeal diseases. Statistical analysis was performed by means of sensitivity/specificity, simple regression, stepwise regression and stepwise logistic regression. The results showed that the ability to detect a laryngeal obstruction was acceptable and that Rosc-Insp, peak inspiratory flow (PIF) and forced inspiratory volume in one second (FIV1) seemed to be the best variables for detection of a laryngeal obstruction. None of the studied noninvasive methods appeared to be adequate for quantification of laryngeal obstruction.