Arterial blood gas anomaly in canine hepatobiliary disease

Abstract

Arterial blood gas analysis is an important diagnostic and monitoring tool for respiratory abnormalities. In human medicine, lung complications often occur as a result of liver disease. Although pulmonary complications of liver disease have not been reported in dogs, we have frequently encountered hypoxemia in dogs with liver disorders, especially extrahepatic biliary obstruction. In addition, respiratory disorders account for 20% of perioperative fatalities in dogs. Therefore, in this study, we evaluated the respiratory status in dogs with hepatobiliary disease by arterial blood gas analysis. PaO₂ and PaCO₂ were measured. Alveolar-arterial oxygen difference (AaDO₂), the indicator of gas exchange efficiency, was calculated. Compared to healthy dogs (control group), hepatobiliary disease dogs had significantly lower PaO₂ and higher AaDO₂. Hypoxemia (PaO₂ of ≤80 mmHg) was observed in 28/71 dogs with hepatobiliary disease. AaDO₂ was higher (≥30 mmHg) than the control group range (11.6 to 26.4 mmHg) in 32/71 hepatobiliary disease dogs. By classifying type of hepatobiliary disease, dogs with extrahepatic biliary obstruction and chronic hepatitis showed significantly lower PaO₂ and higher AaDO₂ than in a control group. Dogs with chronic hepatitis also had significantly lower PaCO₂. The present study shows that dogs with hepatobiliary disease have respiratory abnormalities more than healthy dogs. Preanesthetic or routine arterial blood gas analysis is likely beneficial to detect the respiratory abnormalities in dogs with hepatobiliary disease, especially extrahepatic biliary obstruction and chronic hepatitis.