Tatsuki Sugiura

Influence of Nasal Resistance on Initial Acceptance of Continuous Positive Airway Pressure in Treatment for Obstructive Sleep Apnea Syndrome

Background: Continuous positive airway pressure (CPAP) is considered as the standard therapy for obstructive sleep apnea syndrome (OSAS), but some patients with OSAS are unable to accept CPAP due to nasal obstruction and poor nasal airflow. Objectives: We assessed the influence of nasal resistance before beginning CPAP treatment on the initial acceptance of CPAP in OSAS patients. Methods: The study subjects comprised 77 patients (74 males, 3 females) with primary OSAS, all of whom received CPAP treatment with nasal masks. Before trials, all subjects underwent overnight polysomnography, and nasal resistance was measured with active anterior rhinomanometry in the seated position on the first day of CPAP trial. Results: The CPAP treatment was accepted by 56 patients after the initial trials with overnight polysomnography. Body mass index, the number of apnea/hypopnea episodes per hour (apnea/hypopnea index; AHI), and the number of episodes per hour with an oxygen desaturation of >3% (oxygen desaturation index) were significantly higher (p < 0.01) and nasal resistance was lower (p = 0.003) in patients who accepted CPAP than in those who did not. Logistic regression analysis, with patient age, body mass index, Epworth sleepiness scale score, AHI, oxygen desaturation index, and nasal resistance before CPAP treatment as explanatory variables, showed that nasal resistance (OR + 0.1 Pa/cm3/s: 1.48; p = 0.002) and AHI (OR + 1 event/h: 0.93; p = 0.003) were significant factors for CPAP non-acceptance. Conclusions: Nasal resistance before the beginning of CPAP treatment has a significant effect on the acceptance of CPAP in OSAS patients, and hence, could be a predictive parameter for the initial acceptance of CPAP.

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.

Upper airway morphology in patients with obstructive sleep apnea syndrome: Effects of lateral positioning

OBJECTIVES The aim of this study was to clarify the interaction of lateral and supine sleeping positions with upper airway morphology in patients with obstructive sleep apnea syndrome (OSAS). PATIENTS AND METHODS Thirty-one patients with OSAS, whose apnea/hypopnea index (AHI: number of episodes of apnea or hypopnea per hour) was over 15, were enrolled in this study. Subjects were divided in two groups according to positional effects on their AHI. In six patients, a lateral posture decreased the AHI by 50% and more (responders); in the remaining 25, lateral positioning decreased the AHI by less than 50% or even increased the AHI (nonresponders). AHI and body mass index (BMI) of the responders tended to be lower and their mean age was younger than those of nonresponders, but these differences were not statistically significant. We compared the upper airway morphology between the responders and the nonresponders regarding the tonsil size, tongue position (modified Mallanpati grade, reflecting the space between the tongue and soft palate) and the width of the fauces and retroglossal space. In addition, we compared nasal resistance between the groups using active rhinomanometry. RESULTS The width of the fauces was significantly greater (P=0.041) among the responders than among the nonresponders. However, the other parameters were not consistently different between the two, and these differences were not statistically significant either. CONCLUSIONS The distance between the fauces was the sole morphological feature to distinguish the responders and the nonresponders to the positional therapy in patients with OSAS. Lateral positioning during sleep might be a recommended sleep hygiene for OSAS patients with wide fauces.

Platelet GPIIb/IIIa Is Activated and Platelet-Leukocyte Coaggregates Formed in vivo during Hemodialysis

Background/Aim: During hemodialysis, platelets and leukocytes are activated and form platelet-leukocyte coaggregates in which GPIIb/IIIa (CD41/CD61) and CD62P (P-selectin) are involved. However, it is still controversial whether platelet activation and platelet-leukocyte coaggregate formation are dependent on the dialyzer membrane material. Method: We examined the appearance of activation-dependent antibody on platelets as an index of platelet activation, and the appearance of platelet-specific antigen on leukocytes as an index of platelet-leukocyte coaggregation, during hemodialysis in 7 patients treated using regenerated cellulose (RC) membrane and next using polysulfone (PS) membrane. In order to reduce the influence of factors other than dialyzer membrane material, this study was conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate. Moreover, flow cytometric techniques with whole blood were employed, which reduce artificial cell activation during the cell or plasma separation procedure. The platelet-specific monoclonal antibodies used in this study were anti-CD61, PAC-1 (which recognizes only the conformationally activated GPIIb/IIIa) and anti-CD62P. Results: Changes in the percentage of PAC-1-positive platelets were significantly greater during hemodialysis with RC than with PS. However, changes in the percentage of CD62P-positive platelets were not significantly different between hemodialysis with RC and PS. Changes in the percentage of CD61- or CD62P-positive leukocytes were significantly greater during hemodialysis with RC than with PS. Although changes in percentage of PAC-1-positive platelets did not parallel those of CD62P-positive platelets during hemodialysis, there was a significant positive correlation between the percentage of CD61-positive leukocytes and the percentage of CD62P-positive leukocytes. Conclusion: This study, conducted in a prospective crossover fashion using a pyrogen-free bicarbonate dialysate in order to reduce the influence of factors other than the dialyzer membrane material, demonstrated that both the degrees of GPIIb/IIIa activation and platelet-leukocyte coaggregation were greater during hemodialysis with RC than PS.

Changes in Mac-1 and CD14 Expression on Monocytes and Serum Soluble CD14 Level during Push/Pull Hemodiafiltration

Background/Aim: Employment of treated dialysate as replacement fluid raises concerns about exposure of patients to pyrogenic substances. This study was undertaken to evaluate the safety of treated dialysate as the replacement fluid for push/pull hemodiafiltration. Methods: In the present study, changes in the expressions of Mac-1 and CD14 on monocytes, which are upregulated by monocyte activation, were analyzed by flow cytometry, and the serum level of sCD14 which elevates by monocyte activation was measured by enzyme-linked immunosorbent assay (ELISA) during treatment in 7 patients on hemodialysis with regenerated cellulose (RC) membrane, polysulfone (PS) membranes and by push/pull hemodiafiltration (HDF) with PS membranes in a cross-over fashion. Results: During hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration with PS, both Mac-1 and CD14 expressions on monocytes significantly increased by passing through the artificial kidneys, and, accordingly, the respective values downstream of the artificial kidneys were significantly higher than the predialysis values, even when the lipopolysaccharide level in dialysate was not detectable by Limulus assay. There was no significant variation in serum sCD14 levels during any of the hemodialysis with RC, hemodialysis with PS or push/pull hemodiafiltration. However, during hemodialysis with PS or push/pull hemodiafiltration with PS, changes in Mac-1 and CD14 expression on monocytes were significantly smaller than those during hemodialysis with RC. Conclusion: Monocytes are activated to a greater extent during hemodialysis with RC membranes than during push/pull HDF with PS membranes. We consider that push/pull HDF may be safer than hemodialysis with RC membrane and that it is as safe as hemodialysis with the PS membrane in terms of monocyte activation, when pyrogen-free dialysate is employed.