Recumbent deoxygenation in mild/moderate liver cirrhosis: the "clinodeoxia". The ortho-clino paradigm.
BACKGROUND
While the effects of postural change on arterial oxygenation have been well documented in normal subjects, and attributed to the relationship of closing volume (CV) to the tidal volume, in liver cirrhosis such postural changes have been evaluated mainly in a rare, peculiar clinical end-stage condition which is characterized by increased dyspnea shifting from supine to upright position ("platypnea"). The latter is associated with worsening of PaO2 ("orthodeoxia"). We evaluated the effects of postural changes on arterial oxygenation in patients affected by mild/moderate liver cirrhosis.


METHODS
We performed pulmonary function tests and arterial blood gas evaluation in sitting and supine positions in 22 patients with mild/moderate liver cirrhosis, biopsy-proved, and 22 matched non-smokers control subjects.


RESULTS
Recumbency elicited a decrease of PaO2 (Δ(sup-sit)PaO2) in 19 out of 22 controls and in all but one cirrhotics. The magnitude of this postural change was significantly (p = 0.04) greater in cirrhotics (9.6 ± 5.3%) compared to controls (6.7 ± 3.7%). In the subset of cirrhotics younger than 60 yrs and with PaO2 greater than 80 mmHg in sitting position, the Δ(sup-sit)PaO2 in recumbency further increased to 12 ± 5.8%, significantly (p = 0.014) greater than in same subgroup of controls (7.1 ± 3.8%).


CONCLUSIONS
In mild/moderate liver cirrhosis the postural variations in PaO2 follow the normal trends, but are of greater magnitude probably as a consequence of hypoventilated units of lung for postural and disease-linked tidal airway closure, resulting in more pronounced recumbent hypoxemia ("clinodeoxia").
Department of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; The Lovelace Respiratory Research Institute, Albuquerque, NM, USA; Pulmonary Department, University of Parma, Parma, Italy. Electronic address: fpolverino@partners.org.
Francesca
F
Polverino
Department of Pulmonary Medicine, Cava de' Tirreni Hospital, Cava de' Tirreni, Italy.
Carlo
C
Santoriello
Lung Diseases Institute, University of Messina Medical School, Messina, Italy.
Filippo
F
Andò
Lung Diseases Institute, University of Messina Medical School, Messina, Italy.
Giuseppe
G
Girbino
Department of Experimental Medicine, Second University of Naples, Naples, Italy.
Donato
D
Cappetta
Department of Experimental Medicine, Second University of Naples, Naples, Italy.
Bruno
B
D'Agostino
Lung Diseases Institute, University of Salerno, Italy.
Alessandro
A
Vatrella
Department of Pulmonary Medicine, Cava de' Tirreni Hospital, Cava de' Tirreni, Italy; Lung Diseases Institute, University of Messina Medical School, Messina, Italy.
Mario
M
Polverino
Meakins-Christie Laboratories, McGill University, Montreal, PQ, Canada.
Joseph
J
Milic-Emili
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D008103:Liver Cirrhosis / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D011187:Posture / Q000502:physiology; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology
D010100:Oxygen
Cirrhosis; Clinodeoxia; Postural hypoxemia