Dichotomous physiological effects of nocturnal external nasal dilation in heavy snorers: the answer to a rhinologic controversy?

The purpose of this article was to study the impact of external dilation on nasal airway dimensions, sleep architecture, and snoring. Eighteen heavy snorers without severe obstructive sleep apnea syndrome (mean apnea-hypopnea index (AHI) 9.3) reporting nocturnal nasal obstruction were enrolled in a randomized (controlled) cross-over study, evaluating subjective and objective effects of external nasal dilation (Breathe Right, 3M). The active dilator was also worn during a one-week pretrial run-in period. Polysomnography, recording of snoring sounds, and repeated acoustic rhinometry were performed on two consecutive nights, one with the active dilator and one with a placebo strip. The significant subjective improvement reported during the run-in period compared to the preceding period without dilator (p < 0.01), remained only for nasal patency (p < 0.05) when comparing the two nights in the sleep laboratory. The nasal dimensions increased significantly (p < 0.001) with the active dilator compared to placebo, both in the evening and the next morning. In a subgroup (n = 6) of habitual snorers (AHI < 10) with severe morning obstruction (combined minimal cross-sectional area < 0.6 cm2), external dilation significantly improved the mean sleep PaSO2 (92.4 --> 96.7) and the percentage of sleep with a PaSO2 < 95% (49.9% --> 4.9%) (p < 0.05). In this subgroup there was a trend toward reduction in (7.4 --> 5.4) (p = 0.06), whereas the AHI increased significantly in the group of 12 with larger nocturnal nasal dimensions (p < 0.05). Duration and intensity of snoring remained unchanged regardless of the subgrouping. Objective beneficial effects were restricted to nocturnal oxygen saturation and AHI in a subgroup of habitual heavy snorers identified by repeated acoustic rhinometry, in whom external dilation objectively relieved marked nocturnal nasal obstruction. This finding may provide a logical explanation for the conflicting results of medical, surgical, and mechanical expansion of the nasal dimensions on snoring and sleep disturbances. (American

Does the oral device Noiselezz prevent sleep apnoea?

Both snoring and apnoea are caused by the collapse of soft tissue in the upper airways during sleep. Increasing the cross-sectional area of the airways in these segments by moving the mandible and/or the tongue forward stabilizes the upper airways in obstructive sleep apnoea syndrome (OSAS) patients. The aim of this study was to determine the effect of Noiselezz, which is an oral appliance of the mandibular advancing type, designed for easy use. Twenty-one patients, all men (aged 50.6 +/- 10.4, body mass index 26.5 +/- 3.3) were included in the study. Polysomnography (PSG) was performed before the patients started using Noiselezz. After a period of 2 weeks accustomizing to the oral device, the patients had another PSG performed with Noiselezz inserted. We found no significant differences in total sleep time, percentage of time spent snoring, duration of rapid eye movement (REM) sleep, slow-wave sleep, inter-sleep wake and sleep efficiency, apnoea/hypopnoea index (AHI) or lowest measured oxygen saturation after apnoea (minSaO2). No significant differences were found in the localization of obstructions or intrathoracal inspiratory pressure with and without the use of the Noiselezz oral device. Three patients (14%) reported satisfaction with treatment by the oral device. All three continued to use Noiselezz as treatment. The rest of the patients (86%) either did not tolerate the device at all or tried it for a period and then requested alternative treatment (n = 12). Most patients found the oral device "Noiselezz" inconvenient to use, and our results show that the device has little or no effect on snoring and sleep apnoea.

Diagnosing respiratory events and tracing air flow by internal thermistors.

We have developed a new method to measure flow in patients with sleep-related breathing disorders (SRBD). These flow sensors are modified thermistors located in the same sensors we use for pressure measurement in the upper airways to find the obstructive segments during apnoeas. The aim of this study was to test if using internal thermistors as indicator of air flow has advantages compared with the external thermistor method in detecting respiratory events. A total of 50 consecutive patients with an apnoea-hypopnoea index (AHI) of more than 15 were studied. A standard nocturnal polysomnography (PSG) with both internal and external thermistors was performed in all patients. To estimate the patients' AHI, a detailed analysis viewing all parameters except external and internal thermistors was performed. This was followed by an analysis viewing only internal thermistors signals indicating airflow in the pharynx, and finally an analysis viewing only external thermistor signals indicating air flow at the mouth and nose. Mean AHI measured by the three methods showed 49.8 (SD 23.4) by the PSG, 47.8 (SD 24.9) by internal thermistors alone, and 31.5 (SD 22.2) by external thermistors. There was no statistical difference between AHI detected by PSG and internal thermistors, but highly significant differences between PSG and external thermistors (p < 0.001). The external thermistors missed an average of almost 20 respiratory events per hour.

Tracing air flow and diagnosing hypopnoeas in normal subjects.

Hypopnoea is a type of sleep-related breathing disorder (SRBD), and the apnoea plus hypopnoea index (AHI) is usually computed to diagnose this condition. We introduce a new method to diagnose flow with internal thermistors located on the same sensors as we use to diagnose obstructive segments in patients with sleep-related breathing disorders. The aim of this study is to investigate whether internal thermistors are reliable for diagnosis of hypopnoeas. Fifteen volunteers participated in a prospective comparative study in healthy subjects without SRBD. We simultaneously measured minute ventilation by a pneumotachograph and indirectly air flow by internal thermistors in awake subjects was manually analysed from both the pneumotachograph and the internal thermistors. We found a close agreement between the different methods for percentage reduction in air flow both for the hypopnoea and the apnoea data. The mean difference between the percentage reduction in flow from normal breathing to hypopnoea measured by the pneumotachograph and the internal thermistors lying supine was 3.8% (SD 7.4). In the lateral position the corresponding figures were 1.0% and 4.6. This study in awake, normal subjects indicates that internal thermistors are as reliable as the pneumotachograph in diagnosing hypopnoeas and we believe that the reliability of this monitoring method is adequate for clinical use.

Internal thermistors in differentiating between oral and nasal breathing during sleep.

To select patients with sleep apnoea hypopnoea syndrome (SAHS) who will benefit from surgery, we use information from four different pressure sensors in the upper airways and oesophagus during polysomnography (PSG). These pressure sensors also have the ability to act as internal thermistors and can hence indirectly measure flow as well as pressure. This new method for measuring flow has proven to be very accurate for scoring hypopnoeas as well as apnoeas. The aim of this study was to determine whether the flow and pressure sensors located in the epipharynx, oropharynx and hypopharynx could differentiate between nasal and oral breathing. The design was a prospective cross-over study in 124 patients referred to the hospital for SAHS diagnosis. The awake patients were asked to breathe first through the nose and then through the mouth while the nose was blocked with a clip. A standard nocturnal PSG with pressure and flow measurement in the upper airways was performed in all patients. The procedure was repeated in a lateral position, and again the next morning in 32 of the patients. Reduction in flow signals from the nose was calculated, and a paired t-test was performed for statistical analysis. The difference between nasal and oral breathing was quite distinct in the flow tracings from the internal thermistors. The mean reduction in nasal flow signals when changing from nasal to oral breathing was 83.7% (SD 14.5, p < 0.0001). The same was seen in a lateral position, 82.2% (SD 16.4, p < 0.0001). Testing for changes in properties of the internal thermistors revealed no significant difference between the reduction in flow when the test started and after the patients had slept the whole night (p > 0.1). It is possible to differentiate between nasal and oral breathing using internal thermistors.

Lung function and radiographic signs of pulmonary fibrosis in oil exposed workers in a cable manufacturing company: a follow up study.

Thirty seven workers employed for at least three years in oil impregnation of cables during 1963-83 were followed up in 1990 to study the development of pulmonary fibrosis and consequences for lung function. They had been exposed to concentrations of mineral oil vapours of 50-100 mg/m3, and concentrations of oil mist of 0.5-1.5 mg/m3. All 29 living persons were traced. For each person one control matched for age, height, and smoking habits was selected. Among 25 workers followed up with radiographic studies, 10 cases of pulmonary fibrosis were found, by contrast with one case in the control group (p less than 0.01). Chest radiographs from 1979-80 and 1989-90 were reviewed. The profusion of small opacities increased in seven of 16 persons during 10 years without exposure. Seventeen workers had lung function tests. The bellows function (VC, FEV1, MVV) and lung volumes (TLC, RV) did not differ from those in the matched controls (p greater than 0.05), but the carbon monoxide transfer factor (TLCO) was decreased. The largest reduction of TLCO (1.5 mmol/kPa/min) was found among workers exposed for 10 years or more (p less than 0.05). Arterial blood gases were not affected at rest, but during maximum tread mill exercise, PO2 and HbO2 were reduced in exposed workers compared with controls, particularly among those exposed for at least 10 years (p less than 0.05). Exposure to low viscosity oil mist and vapour is the most plausible cause of the fibrosis. Unaffected bellows function, reduced TLCO, and decreased arterial blood oxygen during exercise is compatible with peribronchiolar fibrosis.

[Occupational pneumoconiosis and x-ray check-ups performed by the National Board of Occupational Protection]. / Yrkesrelatert støvlungesykdom og Arbeidstilsynets røntgenkontroll.

In Norway the Directorate of Labour Inspection's pneumoconiosis panel consists of two radiologists. Pneumoconioses are notifiable diseases, and doctors are required by law to notify suspected and confirmed cases to the Directorate of Labour Inspection. Chest films are sent to the Directorate. The pneumoconiosis panel reads and classifies the cases according to ILO-standards. During a 9 months' period, 177 chest films were examined, 162 of which were from persons exposed mainly to asbestos. In this group of 162, 96 persons had parietal pleural plaques only, and 21 or 17% had pleuropulmonary asbestosis with visceral pleural thickening from which fibrous streaks radiated into the lung. Ten persons had pulmonary asbestosis alone or combined with pleural plaques. This group included one mesothelioma. The notification form used by the doctors demands adequate information on occupational history and exposures. More specific information would facilitate the work of the panel.

Pulmonary fibrosis in cable plant workers exposed to mist and vapor of petroleum distillates.

Twenty-five cable plant workers exposed to mists and vapors of mineral oils and kerosene for 5-35 years have been investigated in a cross-sectional, matched pairs study. The exposed cohort and the referents were examined by radiology, pulmonary function measurements, and a questionnaire for symptoms of respiratory disease. Lung tissue from a deceased worker with 35 years of exposure was investigated by histopathologic methods and by scanning electron microscopy. Exposure measurements were performed by personal sampling. Previous employment and smoking habits were recorded for all subjects. An increased prevalence of slight basal lung fibrosis was found in chest films of the exposed workers. Pulmonary fibrosis was confirmed histopathologically. A moderately decreased vital capacity (VC) and forced expiratory volume (FEV1) was found. Oil mist was measured to time-weighted average levels of 0.15-0.30 mg/m3 with short-term vapor exposure of up to 4000 mg/m3. It is concluded that mists and vapors from petroleum distillates are the most probable causes of the findings.

Parietal pleural plaques: a comparison between autopsy and X-ray findings.

In a series of 402 consecutive autopsies, parietal pleural plaques (PP) were found in 68 individuals above 40 years of age. The frequency of PP was 26.9% in males and 3.1% in females. In 28 cases chest roentgenographs taken shortly before death were available. These films were randomly mixed with chest roentgenographs from 33 subjects who had subsequently died and in whom no PP had been found at autopsy. All films were scrutinized by two experienced readers, ignorant of the case histories and autopsy findings. In less than half the PP cases was this diagnosis suggested from the roentgenological examination. On the other hand, the readers had 13 and 14 cases with positive or uncertain findings in the 33 cases with no PP found at autopsy. There was no correlation between plaque area and plaque thickness (r = 0.037). Plaque thickness influenced the accuracy of roentgenological diagnosis significantly. In this series no oblique views were obtained and the X-rays were of mixed quality.

Hysterosalpingography in the evaluation of infertility.

Hysterosalpinography (HSG) was performed in 220 women for evaluation of infertility. Laparoscopy or laparotomy for final assessment of tubal patency were carried out in 110. HSG revealed a normal tubal patency in 66.8 per cent, whereas abnormal patency was found in 24.1 per cent. At operation, 85.7 per cent of the HSG diagnoses were confirmed. A clear correlation existed between previous lesions in the genital tract and pathologic findings at HSG and operation. The pregnancy rate following HSG was 15.4 per cent. It is concluded that HSG is of great value in the initial evaluation of infertility. The findings facilitate the decision regarding the final operative procedure: laparoscopy or laparotomy.