PT - JOURNAL ARTICLE AU - Georg Nilius AU - Ulrike Domanskie AU - Karl-Josef Franke AU - Karl-Heinz Ruhle AU - Hartmut Schneider TI - Comparing different flow rates (20 and 35 l/min) under high-nasal flow therapy for the obstructive sleep apnoea syndrome (OSAS) DP - 2011 Sep 01 TA - European Respiratory Journal PG - p2207 VI - 38 IP - Suppl 55 4099 - http://erj.ersjournals.com/content/38/Suppl_55/p2207.short 4100 - http://erj.ersjournals.com/content/38/Suppl_55/p2207.full SO - Eur Respir J2011 Sep 01; 38 AB - Introduction: We have demonstrated that 20 l/min nasal insufflation of airflow (HNF) can treat a subgroup of OSAS patients (Nilius G et al. Chest. 2010; 137:521-8). The aim of this study was to compare the effect of two flow rates (20 l/min (HNF20) and 35 l/min (HNF35)) on sleep disordered breathing.Methods: 18 CPAP-naïve patients (6 women, age 56.6±7.3, BMI 32.6±3.8 kg/m2, ESS 9.3±5.2) with more than 50% Hypopnoeas during a diagnostic night were recruited. During the treatment night both HNF20 and HNF35 were administered in a random order for a minimum of three hours each.Results: The total event rate (AHI) in NREM/REM sleep was at baseline 25±13/37±23, at HF20 L/min 23±14/22±22 and at HF35 L/min 19,0±13/15±18 (P<0.05 for REM). There were significant improvement HI, but AI at 35 L/min versus 20 L/min in NREM and REM sleep. The lack of AI responses was associated with a significant increase in cenctral AI (baseline vs HNF20 vs HNF35; 1 vs 8 vs 6 events/hour). Nevertheless Oxygenation (T90) improved considerably with HNF35 compared to HNF20 and baseline in both sleep states.View this table:Conclusion: A flow rate of 35 LPM of nasal insufflation is more effective in lowing obstructive hypopneas and improving oxygenation than 20 LPM. Nasal insufflation, however, can increase the event rate of central apneas, independently of the flow rate, which might offset therapeutic responses in some patients.