[The oxygen kinetic effect of inhaled iloprost in pulmonary artery hypertension and chronic thromboembolic pulmonary hypertension].
OBJECTIVE
To study the acute oxygen kinetic effect of inhaled iloprost in pulmonary artery hypertension and chronic thromboembolic pulmonary hypertension.


METHODS
Twenty-two and 24 patients who were admitted to our hospital between June 2006 and January 2009 with confirmed diagnosis of pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) respectively were enrolled to this study. During right heart catheterization, the hemodynamics and oxygen kinetics were monitored at baseline and after inhaling Iloprost (20 micrograms).


RESULTS
At baseline, the arterial partial pressure of oxygen (PaO2) was (63 +/- 10) mm Hg (1 mm Hg = 0.133 kPa) and (59 +/- 10) mm Hg respectively in PAH and CTEPH patients, and the oxygen delivery index (DO2I) and oxygen consumption index (VO2I) were (458 +/- 136) ml x min(-1) x m(-2) and (135 +/- 53) ml x min(-1) x m(-2) in PAH patients respectively, and (386 +/- 92) ml x min(-1) x m(-2) and (131 +/- 43) ml x min(-1) x m(-2) in CTEPH patients respectively. Three minutes after inhaling Iloprost, for PAH and CTEPH patients, the pulmonary shunt rate (Qs/Qt) all increased significantly (all P < 0.05, respectively) as well as the difference of oxygen partial pressure between pulmonary alveoli and artery (P[A-a]O2, all P < 0.05, respectively), and the arterial oxygen content (CaO2) all decreased significantly (all P < 0.05, respectively). The oxygenation parameters of mixed venous blood, oxygen extractive rate and DO2I did not change significantly, but VO2I declined to different extent. The extent of change after inhaling Iloprost for all oxygen kinetic parameters were similar between PAH and CTEPH patients. At baseline, mixed venous oxygen saturation (SvO2), venous oxygen content (CvO2) and DO2I in CTEPH patients were lower than those in PAH patients. After inhaling Iloprost, in CTEPH patients, PaO2, SvO2 and CvO2 were lower than those in PAH patients.


CONCLUSIONS
There were hypoxemia and abnormality of oxygen kinetics in PAH and CTEPH patients. After inhaling Iloprost, pulmonary shunt increased without improvement in oxygen kinetics. Oxygenation should be monitored closely and supply oxygen supplied for CTEPH when inhaling Iloprost.
Cui
Na
N
Beijing Institute of Respiratory Medicine, Beijing Chao-Yang Hospital, Capital Medical University, 100020, China.
Yang
Yuan-hua
YH
Xie
Wan-mu
WM
Ma
Zhan-hong
ZH
Luo
Ling
L
Wang
Chen
C
D000280:Administration, Inhalation; D000328:Adult; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000378:metabolism* / Q000503:physiopathology; D016285:Iloprost / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D011651:Pulmonary Artery / Q000503:physiopathology; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*
D014665:Vasodilator Agents; D016285:Iloprost; D010100:Oxygen