Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Nanou V, Armeniakou E, Gerovasili V, Tasoulis A, Perpati G, Leontis M, Tzanis G, Roussos Ch, Nanas S, Pouliou E. Am J Respir Crit Care Med. 2008;177(Abstracts Issue):A456.
Introduction: NIRS measures the balance between muscle capillary blood flow and muscle O2 uptake in the microcirculation. We hypothesized that microcirculation might also be altered. We assessed microcirculatory alterations in CF patients compared to healthy subjects (HS) using NIRS, and correlated these alterations with other indices of disease severity that reflect muscle metabolic defect, such as VO2/t-slope.
Methods: We studied 16 CF patients (12 males; mean age=244 y) and 10 HS (7 males; mean age=28±3 y). A probe was placed on the thenar muscle and a pneumatic cuff above the elbow was inflated to 50mmHg above the patients systolic blood pressure for 3 min. Tissue O2 saturation (oxygenated Hg/total Hg) was measured during rest (StO2), occlusion (O2 consumption rate), and release (reperfusion rate). Then 12 CF patients underwent maximal cardiopulmonary exercise testing (CPET) and the first-degree slope of VO2 decline for the first minute of recovery period (VO2/t-slope) was calculated by linear regression.
Results: StO2 and O2 consumption rate were significantly lower (p<0.05) in patients with CF as compared to HS (76±7.5 vs. 85±5.0% and 30±11 vs. 38.1±11 ml/kg/min respectively), while there was no significant difference in the reperfusion rates (455±174 vs. 480±133). Tissue O2 consumption rate correlated with VO2/t-slope (r=0.689; p=0.013).
Conclusions: NIRS is a rapid and non-invasive means of measuring impairments in the peripheral microcirculation of CF patients. Impairments in microcirculation (O2 consumption rate) can be correlated to another disease severity index that reflects muscle metabolic dysfunction (VO2/t-slope).