Dh. Roberts et al., Oxygen therapy improves cardiac index and pulmonary vascular resistance inpatients with pulmonary hypertension, CHEST, 120(5), 2001, pp. 1547-1555
Citations number
32
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Study objectives: We tested the hypothesis that breathing 100% oxygen could
result in selective pulmonary vasodilatation in patients with pulmonary hy
pertension, including those patients who would not meet current Health Care
Finance Administration guidelines for long-term oxygen therapy.
Design, setting, and patients: From 1996 to 1999, 23 adult patients (mean /- SEM age, 51 +/-4 years) with pulmonary arterial hypertension without lef
t-heart failure underwent cardiac catheterization in a university teaching
hospital while breathing air and then 100% oxygen.
Measurements and results: Treatment with 100% oxygen increased arterial oxy
gen saturation (91 +/-1% to 99 +/-0.1%, p<0.05) and Pao(2) (64<plus/minus>3
to 309 +/- 28 min Hg, p<0.05). Treatment with 100% oxygen also decreased m
ean pulmonary artery pressure (56<plus/minus>3 to 53 +/-2 mm Hg, p<0.05) an
d increased cardiac index (2.1<plus/minus>0.1 to 2.5 +/-0.2 L/min/m(2), p<0
.05). Calculated mean pulmonary vascular resistance (PVR) decreased from 14
.1<plus/minus>1.4 to 10.6 +/-1.0 Wood units (p<0.05). Vasodilatation with 1
00% oxygen occurred preferentially in the pulmonary circulation (PVR/system
ic vascular resistance, 0.53<plus/minus>0.04 to 0.48 +/-0.03; p<0.05). The
magnitude of the PVR response to oxygen therapy was correlated only with de
creasing patient age (r=0.45, p<0.05).
Conclusions: Treatment with 100% oxygen is a selective pulmonary vasodilato
r in patients with pulmonary hypertension, regardless of primary diagnosis,
baseline oxygenation, or right ventricular function. Development of diseas
e-specific oxygen prescription guidelines warrants consideration.