Oxygenation abnormalities in normoxemic patients with mild liver cirrhosis.
OBJECTIVE
Nitric oxide (NO) production is enhanced in patients with liver cirrhosis (LC). Although most patients with mild LC have neither dyspnea nor platypnea, they might have mild oxygenation abnormalities due to intrapulmonary vasodilatation caused by increased NO. We investigated whether oxygenation abnormalities, such as hypoxemia and orthodeoxia, are present in patients with mild LC.


METHODS
We investigated 148 consecutive patients with biopsy-proven chronic liver diseases such as CH (noncirrhotic chronic hepatitis) (n=46), LC(A), LC(B), and LC(C) (LC Child's A, B, and C) (n=18, 51, 33, respectively). The oxygen saturation by pulse oximetry (SpO2) in the supine and upright positions was determined in patients and controls (normal subjects, n=29). The change in SpO2 on standing was defined as deltaSpO2. NO output in exhaled air was measured in 16 patients.


RESULTS
Four patients [two LC(B) and two LC(C)] had hypoxemia (supine SpO2< or =94% and/or upright SpO2< or =94%). Although there was no intergroup difference in the supine SpO2 or the upright SpO2, the deltaSpO2 decreased [control, +0.2+/-0.6%; CH, +0.1+/-0.9%; LC(A), -0.3+/-0.8%; LC(B), -0.2+/-0.9%; LC(C), -0.5+/-1.1%; mean+/-SD; p=0.005] with worsening liver disease, and the prevalence of desaturation on standing (deltaSpO2< or =-1%) increased [control, 7%; CH, 20%; LC(A), 33%; LC(B), 35%; LC(C), 42%; p=0.01]. The NO output was inversely correlated with deltaSpO2 (r=-0.66, p=0.006).


CONCLUSIONS
Desaturation on standing is present in one-third of normoxemic patients with mild LC of Child's A, and is associated with the severity of liver disease. This postural desaturation is correlated with the exhaled NO, which suggests that intrapulmonary vasodilatation may play some role in this phenomenon.
Second Department of Medicine, University of Tokyo.
Taiji
T
Nagata
Akihiro
A
Matsumoto
Yoshio
Y
Uehara
Goh
G
Tanaka
Hitoshi
H
Oonuma
Kei
K
Hara
Kouichi
K
Igarashi
Hisanori
H
Hazama
Yasunobu
Y
Hirata
Yasushi
Y
Shiratori
Masao
M
Omata
D005260:Female; D006801:Humans; D000860:Hypoxia / Q000209:etiology*; D008103:Liver Cirrhosis / Q000150:complications* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism; D010092:Oximetry; D010100:Oxygen / Q000378:metabolism; D010102:Oxygen Inhalation Therapy; D011187:Posture; D011659:Pulmonary Gas Exchange
D009569:Nitric Oxide; D010100:Oxygen