Impaired Liver [unction. The patient with severe liver damage resulting from infectious disease, ethanol abuse, or vascular or biliary congestion requires special consideration before oral surgery is performed. An alteration of dose or avoidance of drugs that require hepatic metabolism
The production of vitamin K-dependent coagulation factors (II, VII, IX, X) may be depressed in very severe liver disease; therefore obtaining a prothrombin time (PT) or partial thromboplastin time (PTT) may be useful
before surgery in patients with more severe liver disease. Portal hypertension caused by liver disease may also cause hypersplenism, a sequestering of platelets causing thormbocytopenia. Finding a prolonged Ivy bleeding timt- reveals this problem. Patients with severe liver dysfunction may require hospitalization for dental. surgery because their decreased ability to metabolize the nitrogen in swallowed blood may cause encephalopathy.. Finally, unless documented otherwise, a patient with
liver disease should be presumed to carry hepatitis virus (Box 1-18).