%0 Journal Article %A János Juhász %A Júlia Juhász %T Comparison of two different O2-delivery systems during exercise in patients with chronic hypoxia %D 2011 %J European Respiratory Journal %P p2182 %V 38 %N Suppl 55 %X Results from case studies using a high-flow oxygen delivery system (TNI®) suggest advantage regarding the oxygenation compared to conventional O2-therapy (LTOT). Aim of the study was to verify the feasibility, safety and clinical significance of TNI® compared to LTOT.Method: 14 patients (pts) with chronic hypoxia underwent standardized treadmill six-minute walk test (6MWT) in a prospective, randomized study. All pts completed 6MWT on room air (basis). Then, they underwent consecutive 6MWTs applying TNI® and LTOT in a random order (40% O2-admixture each). Between 6MWTs, pts had a rest of 30 minutes. We measured walking distance (m), workload performance (Watt), energy expenditure (kcal), and collected data from Borg-dyspnoea-scale (BDS) and blood gas analysis (BGA) before 6MWT and at maximum workload (WLm). Primary outcome measures were ΔPaO2 and ΔPaCO2 from rest to WLm and their relation to walking distance (m/ΔPaO2), exercise performance (Watt/ΔPaO2) and energy expenditure (kJ/ΔPaO2).Results: BDS scores increased from rest to WLm by 5,58±2,15 (basis), 2,67±1,78 (TNI®) and 3,38±2,04 (LTOT) scores. Waking distances during basis, TNI® and LTOT were 182,14 m, 235,86 m and 232,86 m respectively. ΔPaO2 from rest to WLm was higher during LTOT compared to TNI® (-10,19 mmHg vs. -7,80 mmHg respectively) at identical workload performance (43,21 Watt). Workload economy, performance- and energy efficacy was better during TNI® vs. LTOT (30,22 vs. 22,85 m/mmHg; 5,53 vs. 4,24 Watt/mmHg and 2.02 vs. 1,51 kJ/mmHg respectively).Conclusion: TNI® compared to LTOT was safe to deliver O2 for pts with hypoxia during exercise and superior in regard to workload economy, performance- and energy efficiency. %U