RT Journal Article
SR Electronic
T1 LATE-BREAKING ABSTRACT: The value of near infrared spectroscopy in the investigation of peripheral muscle oxygen availability in pulmonary arterial hypertension
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP PA2304
DO 10.1183/13993003.congress-2015.PA2304
VO 46
IS suppl 59
A1 Marios Panagiotou
A1 Ioannis Vogiatzis
A1 Zafeiris Louvaris
A1 Julien S. Baker
A1 Andrew J. Peacock
A1 Martin K. Johnson
YR 2015
UL http://erj.ersjournals.com/content/46/suppl_59/PA2304.abstract
AB Background: Oxygen transport and utilisation by limb muscles are important determinants of exercise capacity. Near infrared spectroscopy (NIRS) offers a real-time non-invasive measuring of local tissue oxygen saturation (StO2): the ratio of oxygenated to total Hb, which reflects the balance between muscle oxygen supply and utilisation. However, the value of NIRS in PAH is not well established.Aims and objectives: To evaluate limb muscle StO2 at rest and during exercise in patients with PAH in comparison to mixed venous oxygen (SvO2).Methods: A prospective cross-sectional study of 18 patients being investigated for PAH was performed. Two single point measurements of quadriceps StO2 (QStO2)were obtained by NIRO-200NX (Hamamatsu Photonics KK, Japan) at rest and during supine cycling (at 50% of VO2peak) during right heart catheterization. These were compared with concurrently obtained measurements of SvO2from the pulmonary artery port of the Swan-Ganz catheter.Results: 18 patients were studied at rest of whom 13 had PAH and 10 were exercised. Combining all the resting and exercise data points (n=28), QStO2 correlated with SvO2 (r=.56, p=0.002). This correlation persisted when looking at rest (r=.56 , p=0.02) and exercise data (r=.80 , p=0.006) separately. There was no correlation between change in QStO2 and change in SvO2 from rest to exercise (r=.49, p=0.14).Conclusions: Quadriceps StO2 correlates well with SvO2 at rest and during exercise. NIRS may provide a non-invasive way of assessment of peripheral tissue oxygen availability in PAH.