Evaluation of High Oxygen Saturation Status in Cirrhotic Patients

Background: Cirrhosis, as the end stage of a variety of chronic liver diseases, can affect oxygenation in patients and make them hypoxic through hepatopulmonary syndrome or portopulmonary hypertension. However, we observed that some patients referring to our center for liver transplantation had high arterial oxygen saturation. Objectives: This study was designed to investigate the presence and association of hemoglobin oversaturation in cirrhotic patients candidate for liver transplantation. Methods: In a cross - sectional study, cirrhotic patients referring to Shiraz Organ Transplantation Center were included from 2013 to 2015. The exclusion criteria were other disorders that might affect O2 saturation and other causes of liver transplantation except for cirrhosis. Also, we excluded all patients with chest X - ray abnormality. Hemoglobin saturation was measured by arterial blood gas analysis. Patients were divided into two groups, oversaturated patients (Hb sat O2 ≥ 98%) as the case group and patients with Hb sat O2 < 98% as the control group. We compared the case and control groups for the cause of cirrhosis, sex, smoking status, age, spirometry, model for end - stage liver disease (MELD) score, and the place of residence’s altitude. After univariate analysis, logistic regression models were used for multivariate analysis and adjusted for significant and near significant (P value < 0.2) covariates. Results: Of 495patients, 18.6% wereoversaturated. Moreover, 64.5% of the controlgroup patientsweremales versus 58.7% of the case group. The mean age of the control group (40.6±14.7) was significantly higher than that of the case group (36.8±15.7) in univariate analysis (P value = 0.02). Hemoglobin oversaturation was significantly higher in patients with auto - immune hepatitis (AIH) than in patients with other causes of cirrhosis (P value = 0.001). There was no significant difference between the case and control groups in other causes of cirrhosis or other factors. In multivariate analysis, just AIH remained statistically significant in the models (odds ratio = 2.03; 95% confidence interval = 1.13 - 3.65; P value = 0.01). After finding an association between AIH and oversaturation, the drugs routinely used for the treatment of AIH were compared between the case and control groups. No significant difference was found between them in using prednisone, azathioprine, and cyclosporine (P values = 0.5, 0.6, and 0.6, respectively). Conclusions: Based on our research, there was an association between oversaturation in cirrhotic patients and AIH. The association was not related to the drugs used for the treatment of AIH.