The Relationship Between Airway Occlusion Pressure and Severity of Liver Cirrhosis in Candidates for Liver Transplantation

BACKGROUND End-stage cirrhosis is an irreversible condition, and liver transplantation is the only treatment option in for the affected patients. Respiratory problems and abnormal breathing are common findings among these patients. In this study, for the first time, we examined the relationship between the severity of liver cirrhosis and respiratory drive measured by mouth occlusion pressure (P0.1). METHODS This was a cross-sectional study conducted on 50 candidates for liver transplantation who were referred to the pulmonary clinic of Imam Khomeini Hospital for pre-operative pulmonary evaluations. Arterial blood gas analysis (ABG), pulmonary function tests, and measurement of P0.1 were performed for all patients. The severity of liver disease was assessed using the Model for End-Stage Liver Disease (MELD) score. RESULTS The median P0.1 was 5 cm H2O. P0.1 was negatively associated with PaCO2 (r = -0.466, p = 0.001) and HCO3- (r = -0.384, p = 0.007), and was positively correlated with forced expiratory volume at 1s (FEV1)/ forced vital capacity (FVC) (r = 0.282, p = 0.047). There was a strong correlation between P0.1 and MELD score (r = 0.750, p < 0.001). Backward multivariate linear regression revealed that a higher MELD score and lower PaCO2 were associated with increased P0.1. CONCLUSION High levels of P0.1 and strong direct correlation between P0.1 and MELD score observed in the present study are suggestive of the presence of abnormal increased respiratory drive in candidates for liver transplantation, which is closely related to their disease severity.