Soichiro Miyazaki

Determining the site of airway collapse in obstructive sleep apnea with airway pressure monitoring

Twenty patients with obstructive sleep apnea (OSA) underwent complete polysomnography and simultaneous upper airway pressure monitoring with a custom‐made, soft silicone‐covered catheter measuring 2.3 mm in diameter. The catheter had four solid‐state microtip pressure sensors positioned in the posterior nasopharynx, immediately caudal to the tip of the uvula, at the level of the hyoid bone, and in the midesophagus. The level(s) of airway collapse was determined by changes in the pressure patterns between transducers. In 14 of the 20 patients, airway collapse was confined or initiated at the oropharyngeal region. The obstruction extended to the base of tongue in 7 and to the entire collapsible upper airway in 2 patients. Four patients had collapse at the base of the tongue and 2 had collapse at the hypopharynx. The site of airway collapse remained fairly constant through various sleep stages and positions. Uvulo‐palatopharyngoplasty (UPPP) and postoperative polysomnography were performed in 4 patients (2 with hypopharyngeal, 1 with base of tongue, and 1 with oropharyngeal airway collapse). Two patients had a favorable response to UPPP.

The influence of sleep position and obesity on sleep apnea

The influence of sleep position and the degree of obesity were examined in 257 subjects with sleep apnea. Subjects were divided into three groups according to obesity: normal weight (body mass index (BMI) under 24.0 kg/m 2 ), mild obese (BMI 24.0–26.4 kg/m 2 ) and obese group (BMI 26.4 kg/m 2 and heavier). The apnea + hypopnea index (AHI), the intraesophageal pressure and the lowest oxygen saturation became significantly worse according to the degree of obesity. The subjects were also divided into two groups according to the reduction in the AHI by lateral position: good responders showed 50% or more reduction of AHI in lateral position and poor responders indicated less than 50% reduction. The percentage of good responders to sleep position change was 90.9% in normal weight group, 74.0% in mild obese group and 57.4% in the obese group. The ratio of the subjects who had indicated two or more obstructive sites in normal weight group was 36.0% in good responders and 40.0% in poor responders. The ratio in the mild obese group was 51.8% in good responders and 66.7% in poor responders. In the obese group, the ratio was 59.4% in good responders and 78.9% in poor responders.

Acoustic Analysis of Snoring and the Site of Airway Obstruction in Sleep Related Respiratory Disorders

Seventy-five adult patients with sleep related respiratory disorders were examined by polysomnography with simultaneous recordings of the intraluminal pressure of the upper airway and snoring sound. Obstructed sites in the upper airway during sleep were determined by comparing the amplitude of respiratory fluctuation of the pressures in the epipharynx, mesopharynx, hypopharynx and esophagus. A definite correlation existed between the intensity of snoring sound and the amplitude of respiratory fluctuation of the intraesophageal pressure. Based on the results of the intraluminal pressure partitioning, the subjects were divided into the soft palate type (28), the tonsil/tongue base type (14), the combined type (27) and the larynx type (6). The average value of fundamental frequency (ff) was 102.8+/-34.9 Hz in the soft palate type, 331.7+/-144.8 Hz in the tonsil tongue base type, 115.7+/-58.9 Hz in the combined type and around 250 Hz in the larynx type.

Evaluation of Type 3 Portable Monitoring in Unattended Home Setting for Suspected Sleep Apnea: Factors That May Affect Its Accuracy

OBJECTIVE: This study evaluates the reliability of type 3 portable monitoring (PM) in a home setting. STUDY DESIGN AND SETTING: Prospective study in sleep laboratory. Type 3 device (Stardust II) was evaluated in comparison with standard polysomnography (PSG) among patients with obstructive sleep apnea. Quality of recorded data and agreement between PM and PSG results were evaluated. RESULTS: Low quality of recorded data was observed only in 5 cases. Pattern of disordered breathing was recognized correctly by PM. Apnea/hypopnea index (AHI) correlated well with a mean bias of 3.7 ± 13.1/h. High sensitivity of PM was observed generally, whereas specificity was lower in mild patients. AHI, record time, and sleep position were found to be the main factors that would affect the accuracy of PM. CONCLUSION: Type 3 PM is feasible in unattended home-setting for routine examination. Influence of the factors above should be comprehensively considered especially for mild patients.

Evaluation of uvulopalatopharyngoplasty in treatment of obstructive sleep apnea syndrome

Many methods have been reported to select the proper candidates for uvulopalatopharyngoplasty (UPPP) among obstructive sleep apnea patients. Polysomnography with intraluminal pressure recordings in the upper airway was found useful to predict obstructive site(s) and hence the success of surgery. According to the pressure analysis, 11 cases with high negative pressure at the mesopharynx were selected for UPPP, while UPPP combined with midline partial glossectomy (UPPP-MLG) was done in 18 cases proved to have high negative pressure difference between the mesopharynx and esophagus. A reduction of the apnea hypopnea index (AHI) of more than 50% after UPPP was found in 8 cases (72.7%) and in 11 cases (61.l%) after UPPP-MLG. It was found that the response rate was lower among the second group if compared to that of the first because of other aggravating factors rather than simple obstruction at the level of the soft palate and or tonsils-tongue base level.

Respiratory disturbance during sleep due to adenoid-tonsillar hypertrophy

The pathophysiologic results of respiratory disturbances caused by adenoid-tonsillar hypertrophy are reported. In each case, we monitored intraesophageal pressure to accurately assess respiratory effort, and recorded a sleep diary to detect disorganized sleep habits and disturbed sleeping-waking rhythms. We noticed that great respiratory effort existed not only during light sleep, but was also continuously observed during deep sleep despite the total disappearance of obstructive apneas. Furthermore, upper airway obstruction caused by adenoid-tonsillar hypertrophy and hypoxemia during sleep in the rapid eye movement stage were found to be closely related to the sudden infant death syndrome. A sleep diary recording sleep habits and regularity of night sleep seems to provide reliable indicators for the determination of surgical intervention.

Reduced nasal resistance after simple tonsillectomy in patients with obstructive sleep apnea

Background The aim of this study was to investigate the effects of simple tonsillectomy on nasal resistance in patients with obstructive sleep apnea syndrome (OSAS). Methods Conventional tonsillectomy was performed in 20 patients who were refractory to treatment with continuous positive airway pressure. The subjects consisted of 17 men and 3 women (mean age, 32.9 ± 6.3 years). The effects of tonsillectomy were evaluated with preoperative and postoperative polysomnography and nasal resistance. Results After tonsillectomy, nasal resistance decreased significantly from 0.39 ± 0.30 Pa/cm3 per second to 0.27 ± 0.16 Pa/cm3 per second (p < 0.05). Simultaneously, the apnea–hypopnea index decreased significantly from 55.7 ± 22.5 to 21.2 ± 14.2 (p < 0.05). There was no significant correlation between tonsillar weight and percentage of change in bilateral nasal resistance (p > 0.05). Conclusion The reduction in nasal resistance induced by simple tonsillectomy could play an important role in improving OSAS, as does nasal surgery or adenotomy.

Influence of alcohol on respiratory disturbance during sleep.

Oxygen saturation was measured in 37 patients with sleep‐related breathing disorders over 2 nights: after alcohol intake and under control conditions. Both the number of 3% oxygen desaturation per hour (ODI3) and the lowest saturation (LSAT) were significantly aggravated after alcohol ingestion. Oxygen saturation was degraded in 28 cases after alcohol intake. In 69% of the cases in which ODI3 increased after alcohol ingestion, the aggravation during the alcohol metabolism time was noted. No correlation was found between the quantity of alcohol and oxygen desaturation following alcohol ingestion. Our study revealed that alcohol aggravates sleep‐related breathing disorders.

Relationship between adenoid size and severity of obstructive sleep apnea in preschool children

OBJECTIVE To investigate the contributions of adenoid and tonsil sizes to obstructive sleep apnea syndrome (OSAS) in normal-weight children in two age categories: preschool and schoolchildren. METHODS Fifty-eight normal-weight (body mass index z-score<2) symptomatic children with OSAS (apnea-hypopnea index ≥ 2) were evaluated. The patients were divided into two age categories: preschool (age<6; n=33) and schoolchildren (age ≥ 6; n=25). Polysomnographic findings and adenoid and tonsil sizes were compared. The relative contributions of body mass index and adenoid and tonsil sizes were also investigated with a regression analysis. RESULTS Adenoid grade and apnea index correlated significantly in preschool children (r=0.45, p<0.01). On regression analysis, adenoid grade was a significant predictor of the apnea index in preschool children. The influence of adenoid hypertrophy decreased from preschool to schoolchildren. Tonsil size had little influence on the apnea index in either group. CONCLUSION Adenoid hypertrophy was a major contributor to OSAS in normal-weight preschool children. The upper airway morphology of younger children with OSAS differed from that of older children with OSAS.

Children with severe or moderate obstructive sleep apnoea syndrome show a high incidence of persistence after adenotonsillectomy

Abstract Conclusion: Persistent obstructive sleep apnoea syndrome (OSAS) occurs in approximately 20% of normal-weight children after adenotonsillectomy (T&A) and, in nearly 70% of them, it is caused by adenoid regrowth. Patients with severe or moderate OSAS showed a high incidence of persistent disease even after T&A. Allergic disease, severity and large adenoid size are associated with adenoid regrowth and persistent disease. Objectives: To investigate factors contributing to persistent OSAS and adenoid regrowth after T&A in normal-weight children. Methods: This was a prospective, observational study at a single institute and involved 49 normal-weight children with severe or moderate OSAS (apnoea–hypopnoea index, AHI, ≥ 5) who underwent T&A. Background information, nasal endoscopic data and pre- and postoperative polysomnographic data were collected. A third polysomnography (PSG) was performed 1.5 year postoperatively in children who subsequently developed symptoms of sleep disturbance. Results: Thirteen children (27%, 13/49) were symptomatic 1.5 years after T&A. Allergic rhinitis (38.5% vs 11.1%, p = 0.03) and allergic disease (69.2% vs 30.6%, p = 0.02) were seen more frequently in these children. A third PSG confirmed persistent disease (AHI ≥ 5) in nine children (18.4%, 9/49). Six children (12.2%, 6/49) were diagnosed as having adenoid regrowth and three (6.1%, 3/49) underwent revision adenoidectomy.