PT - JOURNAL ARTICLE AU - Maria Ström AU - Paul Robinson AU - Emilia Viklund AU - Sanna Kjellberg AU - Per Gustafsson TI - Peripheral airway function in COPD assessed by Sacin and Scond using SF6 and He multiple breath washout DP - 2011 Sep 01 TA - European Respiratory Journal PG - p930 VI - 38 IP - Suppl 55 4099 - http://erj.ersjournals.com/content/38/Suppl_55/p930.short 4100 - http://erj.ersjournals.com/content/38/Suppl_55/p930.full SO - Eur Respir J2011 Sep 01; 38 AB - Background: Peripheral airways, particularly acinar airways, are involved in COPD. Sacin for SF6 reflects ventilation inhomogeneity deep inside the acinus, while Sacin for He reflects inhomogeneity proximally in the acinus, and Scond indicates inhomogeneity in the small conducting airways. We tested the hypothesis that Sacin and Scond are greater for SF6 vs. He in COPD.Methods: Multiple breath SF6 and He washout, using a mass spectrometer, was performed at baseline and post bronchodilator (BD, 400 mcg salbutamol and 80 mcg ipratropium pMDI) prior to spirometry and DLCO: 41 COPD subjects (17M/24F), 45-66 yrs, smoking history 10-75 pack yrs. Reference values for Sacin and Scond were obtained in 46 non-smoking healthy subjects aged 19-71 yrs. Local spirometry and DLCO reference equations were used [1,2]. Results were expressed as median (range) z-scores, and wilcoxon rank sum test used for paired comparisons.Results: SF6 Sacin and Scond z scores were greater than He indices both at baseline and post BD in COPD subjects (p<0.001 for all).View this table:Conclusions: COPD was characterized by greater ventilation inhomogeneity in the distal vs. the proximal acinar portion. The degree of ventilation inhomogeneity found in COPD within the acinus is greater than in the conducting airway zone.References:1. Hedenström et al. Bull Eur Physiopatol Respir. 1985;21:551-7.2. Hedenström et al. Upsala J Med Sci. 1986;91: 299-310.