- Email: [email protected]
Use of online educational module does not improve adherence to clinical follow-up or CPAP treatment for OSA
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Abstracts/Sleep Medicine 16 (2015) S2–S199
Materials and methods: By convenience sampling, all patients diagnosed to have moderate/severe OSA (AHI >15) from April 2013 to December 2013 and a residence within 200 km of Bangalore were contacted by telephone. The subjects were enquired about the compliance of CPAP therapy, and were invited for a visit to the sleep clinic. During this visit, the subjects received a brief explanation of OSA and the use of CPAP regularly. A predefined questionnaire which includes questions on number of hours of use of CPAP, CPAP used for number of nights per week, the challenges in using CPAP, QOL questionnaire and ESS were administered. The use of CPAP machine was noted from the downloaded data from their CPAP machines. The subjects were reminded telephonically about CPAP use every 2 months and returned to the sleep clinic after 6 months for a review. The predefined questionnaire was administered again and the CPAP compliance, QOL and ESS was noted. Results: Twenty five patients consented to participate in the study. Among them 20 subjects were men. The mean age of patients was 50.44 years. Twenty three patients had severe OSA and the mean AHI was 47.8/h. The average BMI of the patients was 32.5 kg/m2. The mean duration of CPAP use as reported by the patients as well as their spouses/ care takers was 320 mins (5 h 20 min). On analyzing the data of the CPAP machine, the mean duration of use was only 233 mins (3 h 53 min). The perceived duration and the actual usage of CPAP machine among OSA patients was significantly different (p = 0.001). Ten of 25 patients had used the device for less than 4 h per night. Subjects reported social factors (noncompliant when relative/ friends visit, or when subject is travelling), dryness of mouth, not reapplying machine after nocturia, power shut down and reduced motivation as reasons for non-compliance to use CPAP. None of them reported any claustrophobia with CPAP. Conclusion: Despite the recognized benefits of CPAP, the acceptance of and adherence with therapy remains a considerable barrier. Objective assessment of CPAP compliance should be a part of routine follow up in OSA. Further studies are required to assess the factors affecting CPAP compliance among patients with OSA.
Results: Sample number (N = 100, men 20, women 80), mean age 48.10 ± 9.868 (men 48.30 ± 10.509, women 48.05 ± 9.771), rank of variables Pair 1 PSQI postoperative-preoperative, negative ranks (N = 20, postoperative < preoperative, mean rank 24.03, sum of ranks 480.50), positive ranks (N = 27, postoperative > preoperative, mean of ranks 23.98, sum of ranks 647.50), Ties (N = 53, postoperative = preoperative), total (N = 100), Pair 2 ESS postoperative– preoperative, negative ranks (N = 13, postoperative < preoperative, mean rank 23.31, sum of ranks 303.00), positive ranks (N = 45, postoperative > preoperative, mean rank 31.29, sum of ranks 1408.00), ties (N = 42, postoperative = preoperative), total (N = 100), Pair 3 SI postoperative-preoperative, negative ranks (N = 16, postoperative < preoperative, mean of ranks 22.25, sum of ranks 356.00), positive ranks (N = 34, postoperative > preoperative, mean of rank 27.03, sum of ranks 919.00), ties (N = 50, postoperative = preoperative), total (N = 100), Pair 4 life satisfaction postoperative– preoperative, negative ranks (N = 22, postoperative < preoperative, mean of rank 23.55, sum of ranks 518.00), positive ranks (N = 25, postoperative > preoperative, mean of rank 24.40, sum of ranks 610.00), ties (N = 53, postoperative = preoperative), total (N = 100), test statistics of Wilcoxon signed rank test, Pair 1 PSQI postoperative– preoperative Z = −0.895a, Asymp. Sig. (two-tailed) = 0.371, Pair 2 ESS postoperative–preoperative Z = −4.317a, Asymp. Sig. = 0.000, Pair 3 SI postoperative-preoperative Z = −2.735a, Asymp. Sig. = 0.006, Pair 4 Life satisfaction postoperative-preoperative Z = −0.491a, Asymp. Sig. = 0.623(a. Based on negative ranks) Conclusion: The above results indicate that the snoring and daytime sleepiness is increased after thyroidectomy This means that the sleep apnea aggravated after surgery. Acknowledgements: Thank you very much for the cooperation of outpatients in head and neck clinic of the Department of Surgery of Jesus Hospital in Jeonju of Korea.
http://dx.doi.org/10.1016/j.sleep.2015.02.479
Use of online educational module does not improve adherence to clinical follow-up or CPAP treatment for OSA L. Fine 1, P. Repovic 1, K. Schulz 2, C. Li 3 1 Swedish Medical Center, United States 2 Clark University, United States 3 University of Pennsylvania, United States
Effects of thyroidectomy for thyroid cancer patients on sleep apnea H. Eun, S. Oh Presbyterian Medical Center – Jesus Hospital, Seonam University College of Medicine, South Korea
Introduction: Thyroidectomy decreases snoring and sleep apnea: fact or fantasy? Some paper claims thyroidectomy decreases snoring and sleep apnea symptoms. But another study claims that the thyroidectomy worsen sleep apnea. This study aims to investigate to evaluate and compare the effects of sleep apnea by thyroidectomy. Materials and methods: A neuropsychiatrist and surgeon investigated with respect to the state before and after surgery for outpatients in head and neck surgery clinic who underwent surgery for thyroid cancer and also searched their medical records. Approval of Institutional Review Board (IRB) and informed consents were done. Socio-demographic data and several scales, past medical history taking data for thyroidectomy and sleep apnea with snoring, preoperative and postoperative Pittsburgh Sleep Quality Index (PSQI), preoperative and postoperative Epworth sleepiness scale (ESS), preoperative and postoperative Snoring Index (SI), preoperative and postoperative Global Life Satisfaction (Index of well-being) scale, chi-square test for some demographic data analysis, Wilcoxon signed rank test for hypothesis testing.
http://dx.doi.org/10.1016/j.sleep.2015.02.480
Introduction: While risks of untreated obstructive sleep apnea (OSA) are well-known, the adherence to treatment remains a challenge. To address this issue through patient education about OSA and its treatment, we use an online educational module (Emmi Solutions, Chicago, IL, USA). Herein we assess if this approach leads to improved treatment adherence. Materials and methods: In this single-center retrospective study, medical records of 61 consecutive patients initially diagnosed with OSA in 2012 were reviewed. Outcomes measured were returned for follow-up at 1 and 2 years, as well as PAP use among patients who had follow-up. Patients who completed education module after the initial visit (n = 25) were compared with those who did not complete it (n = 36) with regard to follow-up and PAP use, using Pearson chi square. To evaluate selection bias, a third cohort of 38 patients who were not assigned educational module was used as a control. Results: Of 99 patients, 61 were asked to review the online educational module; 25 patients completed the module. Among patients assigned to the education module, the likelihood of return for followup and CPAP use at 1 year was not significantly affected by participation in the educational module (follow-up: 64% vs 55%,
Abstracts/Sleep Medicine 16 (2015) S2–S199
χ 2 (1) = 0.435, p = 0.601; CPAP use: 93% vs 100%, χ 2 (1) = 1.327, p = 0.249), and was comparable with patients who were not assigned the educational module. In our cohort, only the severity of OSA significantly correlated with the likelihood of clinical followup at 1 and 2 years (t-test, p = 0.002). Conclusion: Our results suggest that participation in online educational module did not correlate with improved follow-up rate or compliance with CPAP therapy. These findings need to be confirmed in a larger sample. An interactive (two-way) rather than informative (one-way) educational approach may improve compliance with OSA treatment. http://dx.doi.org/10.1016/j.sleep.2015.02.481
Comparing acceptance of four questionnaires by patients of a sleep laboratory in a tertiary hospital H. Glass 1, A. Garay-Molina 2, G. Berigo 3, A. Guimaraes 3, R. Costa 3, L. Flores 3 1 Secretaria de Estado de Saúde do Distrito Federal, Brazil 2 Hospital Santa Lucia, Brazil 3 ESCS-FEPECS, Brazil
Introduction: Questionnaires are important tools for accessing complaints, since they can provide an structured evaluation and anamnesis, as well as permit symptoms quantification. In this study we compared four different questionnaires for assessment of sleep symptoms in regard to patients’ acceptance in a “real life” environment, our sleep laboratory. Materials and methods: Inclusion criteria: patients that were scheduled for diagnostic polisomnography (PSG). Exclusion criteria: Second diagnostic PSG and PSG with devices, like orthodontic or Positive Airway Pressure devices. At PSG test night the technicians asked the patients to answer four questionnaires: Epworth Sleepiness Scale (ESS), MiniSleep Questionnaire (MSQ), our own Sleep Laboratory Questionnaire (SLQ) and a questionnaire of symptoms of sleep disorders (SS), downloaded from “Silent Sleep Partners” website, Canada. Both ESS (AN Bertolazi et al. Portuguese-language version of the Epworth Sleepiness Scale: validation for use in Brazil. J. Bras. Pneumol. 2009; 35(9):877–883) and MSQ (SMGP Togeiro, AK Smith. Diagnostic methods for sleep disorders. Rev. Bras. Psiquiatr. 2005; 27 (Suppl. I):8–15) are translated into Portuguese and validated scales. SLQ is composed of 14 dichotomous questions (Y/N) and 11 categorical questions (No/seldom/sometimes/frequently). SS has 83 dichotomous questions. We used X2 test to compare nonacceptance (frequency of not-responded (NR) items) for each questionnaire. We also compared the non-acceptance for each questionnaire between genders. Results: We included 431 patients, 173 females and 258 males. Age distribution was: < 40:127; 41–60:220; 61–60:220; 61– 80:204; > 80:7. For 234 patients, only ESS and SLQ questionnaires, and for 197 (83 males, 114 females) all four questionnaires were offered. There was no difference in acceptance if the patients received two relatively short or four questionnaires. SLQ (3.25%) and SS (3.57%) had a higher NR-frequency (p < 0.001), than ESS (1.54%) and MSQ (1.31%). NR-percentages for Males were SLQ: 2.17%, ESS: 0.84%; SS: 3.49% and MSQ 1.06%; and females 4.87%, 2.57%, 3.68% and 1.62%, respectively. The size of questionnaires may play a role, as the scales presented were shorter, but seems not to affect acceptance in a linear form, because a very long questionnaire (83 questions) had the same acceptance as a shorter one (25). ESS and SLQ had a higher NR-frequency among women (p < 0.001), but SS and MS displayed no differences due to gender. Many women can
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or do not usually drive and question about sleepiness while driving could not be responded. Conclusion: Brazilian women had lower acceptance to our Sleep Laboratory Questionnaire than men. If size plays an important role remains unclear, but Scales had a higher acceptance than the questionnaires, despite known unfamiliarity of Brazilians with scales. Gender differences may be important when evaluating scales and questionnaires. http://dx.doi.org/10.1016/j.sleep.2015.02.482
Effects of fluid removal by hemodialysis on sleep apnea in end-stage renal disease patients A. Ogna 1, V. Forni Ogna 2, A. Mihalache 1, M. Pruijm 2, G. Halabi 3, O. Phan 4, F. Cornette 1, J. Haba-Rubio 1, M. Burnier 2, R. Heinzer 1 1 Center for Investigation and Research in Sleep (CIRS), University Hospital of Lausanne (CHUV), Switzerland 2 Nephrology and Hypertension Department, University Hospital of Lausanne (CHUV), Switzerland 3 Hemodialysis Unit, Etablissements Hospitaliers Du Nord Vaudois, Yverdon, Switzerland 4 Hemodialysis Unit, Hôpital Intercantonal De La Broye, Payerne, Switzerland
Introduction: Recent observations suggest a role of overnight rostral fluid shift (fluid displacement from the legs to the neck) in the genesis of OSA. Our aim was to investigate the impact of fluid removal by hemodialysis on overnight body fluid shift and on the severity of OSA in end-stage-renal-disease (ESRD) patients. Materials and methods: The severity of OSA was assessed during two consecutive attended polysomnographies (PSG), performed the night before and after an hemodialysis session and expressed as index of obstructive apneas and hypopneas per sleep hour (OAHI). Total body overhydration and leg fluid volume were evaluated by bioimpedance. Neck circumference was assessed before and after each PSG. Results: The mean overnight rostral fluid shift was 1.27 (±0.41) L pre-hemodialysis; it correlated positively with fluid overload volume (r = 0.393, p = 0.02) and decreased significantly posthemodialysis (0.78 (±0.38) L, p < 0.001). The reduction in fluid overload by hemodialysis correlated with the decrease in OSA severity, with a dose-dependent effect (r = 0.494, p = 0.04). Hemodialysis successfully reduced obstructive apnea– hypopnea index only in the group of 12 patients with successful reduction of fluid overload (−19%, p < 0.01) whereas it had no effect in those without fluid reduction. Fluid overload – assessed by bioimpedance – was the best predictor of obstructive apnea–hypopnea index reduction obtained by hemodialysis (standardized r = −0.683, p = 0.01) in multivariate regression analysis. Conclusion: Fluid overload and overnight rostral fluid shift influence OSA severity in ESRD patients undergoing intermittent hemodialysis. Fluid removal by hemodialysis decreases the overnight rostral fluid shift and the severity of OSA with a dosedependent effect. Acknowledgements: This study was supported by unrestricted research grants of the Swiss Kidney Foundation (Schweizerische Nierenstiftung) and the Pulmonary League of Canton Vaud (Ligue Pulmonaire Vaudoise). http://dx.doi.org/10.1016/j.sleep.2015.02.483
Abstracts/Sleep Medicine 16 (2015) S2–S199
Materials and methods: By convenience sampling, all patients diagnosed to have moderate/severe OSA (AHI >15) from April 2013 to December 2013 and a residence within 200 km of Bangalore were contacted by telephone. The subjects were enquired about the compliance of CPAP therapy, and were invited for a visit to the sleep clinic. During this visit, the subjects received a brief explanation of OSA and the use of CPAP regularly. A predefined questionnaire which includes questions on number of hours of use of CPAP, CPAP used for number of nights per week, the challenges in using CPAP, QOL questionnaire and ESS were administered. The use of CPAP machine was noted from the downloaded data from their CPAP machines. The subjects were reminded telephonically about CPAP use every 2 months and returned to the sleep clinic after 6 months for a review. The predefined questionnaire was administered again and the CPAP compliance, QOL and ESS was noted. Results: Twenty five patients consented to participate in the study. Among them 20 subjects were men. The mean age of patients was 50.44 years. Twenty three patients had severe OSA and the mean AHI was 47.8/h. The average BMI of the patients was 32.5 kg/m2. The mean duration of CPAP use as reported by the patients as well as their spouses/ care takers was 320 mins (5 h 20 min). On analyzing the data of the CPAP machine, the mean duration of use was only 233 mins (3 h 53 min). The perceived duration and the actual usage of CPAP machine among OSA patients was significantly different (p = 0.001). Ten of 25 patients had used the device for less than 4 h per night. Subjects reported social factors (noncompliant when relative/ friends visit, or when subject is travelling), dryness of mouth, not reapplying machine after nocturia, power shut down and reduced motivation as reasons for non-compliance to use CPAP. None of them reported any claustrophobia with CPAP. Conclusion: Despite the recognized benefits of CPAP, the acceptance of and adherence with therapy remains a considerable barrier. Objective assessment of CPAP compliance should be a part of routine follow up in OSA. Further studies are required to assess the factors affecting CPAP compliance among patients with OSA.
Results: Sample number (N = 100, men 20, women 80), mean age 48.10 ± 9.868 (men 48.30 ± 10.509, women 48.05 ± 9.771), rank of variables Pair 1 PSQI postoperative-preoperative, negative ranks (N = 20, postoperative < preoperative, mean rank 24.03, sum of ranks 480.50), positive ranks (N = 27, postoperative > preoperative, mean of ranks 23.98, sum of ranks 647.50), Ties (N = 53, postoperative = preoperative), total (N = 100), Pair 2 ESS postoperative– preoperative, negative ranks (N = 13, postoperative < preoperative, mean rank 23.31, sum of ranks 303.00), positive ranks (N = 45, postoperative > preoperative, mean rank 31.29, sum of ranks 1408.00), ties (N = 42, postoperative = preoperative), total (N = 100), Pair 3 SI postoperative-preoperative, negative ranks (N = 16, postoperative < preoperative, mean of ranks 22.25, sum of ranks 356.00), positive ranks (N = 34, postoperative > preoperative, mean of rank 27.03, sum of ranks 919.00), ties (N = 50, postoperative = preoperative), total (N = 100), Pair 4 life satisfaction postoperative– preoperative, negative ranks (N = 22, postoperative < preoperative, mean of rank 23.55, sum of ranks 518.00), positive ranks (N = 25, postoperative > preoperative, mean of rank 24.40, sum of ranks 610.00), ties (N = 53, postoperative = preoperative), total (N = 100), test statistics of Wilcoxon signed rank test, Pair 1 PSQI postoperative– preoperative Z = −0.895a, Asymp. Sig. (two-tailed) = 0.371, Pair 2 ESS postoperative–preoperative Z = −4.317a, Asymp. Sig. = 0.000, Pair 3 SI postoperative-preoperative Z = −2.735a, Asymp. Sig. = 0.006, Pair 4 Life satisfaction postoperative-preoperative Z = −0.491a, Asymp. Sig. = 0.623(a. Based on negative ranks) Conclusion: The above results indicate that the snoring and daytime sleepiness is increased after thyroidectomy This means that the sleep apnea aggravated after surgery. Acknowledgements: Thank you very much for the cooperation of outpatients in head and neck clinic of the Department of Surgery of Jesus Hospital in Jeonju of Korea.
http://dx.doi.org/10.1016/j.sleep.2015.02.479
Use of online educational module does not improve adherence to clinical follow-up or CPAP treatment for OSA L. Fine 1, P. Repovic 1, K. Schulz 2, C. Li 3 1 Swedish Medical Center, United States 2 Clark University, United States 3 University of Pennsylvania, United States
Effects of thyroidectomy for thyroid cancer patients on sleep apnea H. Eun, S. Oh Presbyterian Medical Center – Jesus Hospital, Seonam University College of Medicine, South Korea
Introduction: Thyroidectomy decreases snoring and sleep apnea: fact or fantasy? Some paper claims thyroidectomy decreases snoring and sleep apnea symptoms. But another study claims that the thyroidectomy worsen sleep apnea. This study aims to investigate to evaluate and compare the effects of sleep apnea by thyroidectomy. Materials and methods: A neuropsychiatrist and surgeon investigated with respect to the state before and after surgery for outpatients in head and neck surgery clinic who underwent surgery for thyroid cancer and also searched their medical records. Approval of Institutional Review Board (IRB) and informed consents were done. Socio-demographic data and several scales, past medical history taking data for thyroidectomy and sleep apnea with snoring, preoperative and postoperative Pittsburgh Sleep Quality Index (PSQI), preoperative and postoperative Epworth sleepiness scale (ESS), preoperative and postoperative Snoring Index (SI), preoperative and postoperative Global Life Satisfaction (Index of well-being) scale, chi-square test for some demographic data analysis, Wilcoxon signed rank test for hypothesis testing.
http://dx.doi.org/10.1016/j.sleep.2015.02.480
Introduction: While risks of untreated obstructive sleep apnea (OSA) are well-known, the adherence to treatment remains a challenge. To address this issue through patient education about OSA and its treatment, we use an online educational module (Emmi Solutions, Chicago, IL, USA). Herein we assess if this approach leads to improved treatment adherence. Materials and methods: In this single-center retrospective study, medical records of 61 consecutive patients initially diagnosed with OSA in 2012 were reviewed. Outcomes measured were returned for follow-up at 1 and 2 years, as well as PAP use among patients who had follow-up. Patients who completed education module after the initial visit (n = 25) were compared with those who did not complete it (n = 36) with regard to follow-up and PAP use, using Pearson chi square. To evaluate selection bias, a third cohort of 38 patients who were not assigned educational module was used as a control. Results: Of 99 patients, 61 were asked to review the online educational module; 25 patients completed the module. Among patients assigned to the education module, the likelihood of return for followup and CPAP use at 1 year was not significantly affected by participation in the educational module (follow-up: 64% vs 55%,
Abstracts/Sleep Medicine 16 (2015) S2–S199
χ 2 (1) = 0.435, p = 0.601; CPAP use: 93% vs 100%, χ 2 (1) = 1.327, p = 0.249), and was comparable with patients who were not assigned the educational module. In our cohort, only the severity of OSA significantly correlated with the likelihood of clinical followup at 1 and 2 years (t-test, p = 0.002). Conclusion: Our results suggest that participation in online educational module did not correlate with improved follow-up rate or compliance with CPAP therapy. These findings need to be confirmed in a larger sample. An interactive (two-way) rather than informative (one-way) educational approach may improve compliance with OSA treatment. http://dx.doi.org/10.1016/j.sleep.2015.02.481
Comparing acceptance of four questionnaires by patients of a sleep laboratory in a tertiary hospital H. Glass 1, A. Garay-Molina 2, G. Berigo 3, A. Guimaraes 3, R. Costa 3, L. Flores 3 1 Secretaria de Estado de Saúde do Distrito Federal, Brazil 2 Hospital Santa Lucia, Brazil 3 ESCS-FEPECS, Brazil
Introduction: Questionnaires are important tools for accessing complaints, since they can provide an structured evaluation and anamnesis, as well as permit symptoms quantification. In this study we compared four different questionnaires for assessment of sleep symptoms in regard to patients’ acceptance in a “real life” environment, our sleep laboratory. Materials and methods: Inclusion criteria: patients that were scheduled for diagnostic polisomnography (PSG). Exclusion criteria: Second diagnostic PSG and PSG with devices, like orthodontic or Positive Airway Pressure devices. At PSG test night the technicians asked the patients to answer four questionnaires: Epworth Sleepiness Scale (ESS), MiniSleep Questionnaire (MSQ), our own Sleep Laboratory Questionnaire (SLQ) and a questionnaire of symptoms of sleep disorders (SS), downloaded from “Silent Sleep Partners” website, Canada. Both ESS (AN Bertolazi et al. Portuguese-language version of the Epworth Sleepiness Scale: validation for use in Brazil. J. Bras. Pneumol. 2009; 35(9):877–883) and MSQ (SMGP Togeiro, AK Smith. Diagnostic methods for sleep disorders. Rev. Bras. Psiquiatr. 2005; 27 (Suppl. I):8–15) are translated into Portuguese and validated scales. SLQ is composed of 14 dichotomous questions (Y/N) and 11 categorical questions (No/seldom/sometimes/frequently). SS has 83 dichotomous questions. We used X2 test to compare nonacceptance (frequency of not-responded (NR) items) for each questionnaire. We also compared the non-acceptance for each questionnaire between genders. Results: We included 431 patients, 173 females and 258 males. Age distribution was: < 40:127; 41–60:220; 61–60:220; 61– 80:204; > 80:7. For 234 patients, only ESS and SLQ questionnaires, and for 197 (83 males, 114 females) all four questionnaires were offered. There was no difference in acceptance if the patients received two relatively short or four questionnaires. SLQ (3.25%) and SS (3.57%) had a higher NR-frequency (p < 0.001), than ESS (1.54%) and MSQ (1.31%). NR-percentages for Males were SLQ: 2.17%, ESS: 0.84%; SS: 3.49% and MSQ 1.06%; and females 4.87%, 2.57%, 3.68% and 1.62%, respectively. The size of questionnaires may play a role, as the scales presented were shorter, but seems not to affect acceptance in a linear form, because a very long questionnaire (83 questions) had the same acceptance as a shorter one (25). ESS and SLQ had a higher NR-frequency among women (p < 0.001), but SS and MS displayed no differences due to gender. Many women can
S185
or do not usually drive and question about sleepiness while driving could not be responded. Conclusion: Brazilian women had lower acceptance to our Sleep Laboratory Questionnaire than men. If size plays an important role remains unclear, but Scales had a higher acceptance than the questionnaires, despite known unfamiliarity of Brazilians with scales. Gender differences may be important when evaluating scales and questionnaires. http://dx.doi.org/10.1016/j.sleep.2015.02.482
Effects of fluid removal by hemodialysis on sleep apnea in end-stage renal disease patients A. Ogna 1, V. Forni Ogna 2, A. Mihalache 1, M. Pruijm 2, G. Halabi 3, O. Phan 4, F. Cornette 1, J. Haba-Rubio 1, M. Burnier 2, R. Heinzer 1 1 Center for Investigation and Research in Sleep (CIRS), University Hospital of Lausanne (CHUV), Switzerland 2 Nephrology and Hypertension Department, University Hospital of Lausanne (CHUV), Switzerland 3 Hemodialysis Unit, Etablissements Hospitaliers Du Nord Vaudois, Yverdon, Switzerland 4 Hemodialysis Unit, Hôpital Intercantonal De La Broye, Payerne, Switzerland
Introduction: Recent observations suggest a role of overnight rostral fluid shift (fluid displacement from the legs to the neck) in the genesis of OSA. Our aim was to investigate the impact of fluid removal by hemodialysis on overnight body fluid shift and on the severity of OSA in end-stage-renal-disease (ESRD) patients. Materials and methods: The severity of OSA was assessed during two consecutive attended polysomnographies (PSG), performed the night before and after an hemodialysis session and expressed as index of obstructive apneas and hypopneas per sleep hour (OAHI). Total body overhydration and leg fluid volume were evaluated by bioimpedance. Neck circumference was assessed before and after each PSG. Results: The mean overnight rostral fluid shift was 1.27 (±0.41) L pre-hemodialysis; it correlated positively with fluid overload volume (r = 0.393, p = 0.02) and decreased significantly posthemodialysis (0.78 (±0.38) L, p < 0.001). The reduction in fluid overload by hemodialysis correlated with the decrease in OSA severity, with a dose-dependent effect (r = 0.494, p = 0.04). Hemodialysis successfully reduced obstructive apnea– hypopnea index only in the group of 12 patients with successful reduction of fluid overload (−19%, p < 0.01) whereas it had no effect in those without fluid reduction. Fluid overload – assessed by bioimpedance – was the best predictor of obstructive apnea–hypopnea index reduction obtained by hemodialysis (standardized r = −0.683, p = 0.01) in multivariate regression analysis. Conclusion: Fluid overload and overnight rostral fluid shift influence OSA severity in ESRD patients undergoing intermittent hemodialysis. Fluid removal by hemodialysis decreases the overnight rostral fluid shift and the severity of OSA with a dosedependent effect. Acknowledgements: This study was supported by unrestricted research grants of the Swiss Kidney Foundation (Schweizerische Nierenstiftung) and the Pulmonary League of Canton Vaud (Ligue Pulmonaire Vaudoise). http://dx.doi.org/10.1016/j.sleep.2015.02.483