[Perioperative management of a patient with alcaptonuria--a case report].

Alcaptonuria is a very rare enzymatic disease with a compromised degradation of the amino acids phenylalanine and tyrosine. As a consequence, homogentisic acid accumulates, most of which is cleared by the kidneys. In time, homogentisic acid forms black pigment, which accumulates throughout the body in connective tissue such as cartilage and joints. Apart from superficial discoloration, the most clinical manifestation of the disease is arthropathy, starting in middle age. From the anaesthesiologist's point of view, there is a severe risk of difficult airway because of an advanced stiffness of the cervical spine and a reduced mouth opening in these patients. Due to deformity and stiffness of the spine, difficulties in spinal and epidural anaesthesia must be reckoned with. A further risk for patients with alcaptonuria is cardiac involvement, which occurs later than degenerative changes of the joints. The accumulated pigment most likely adds to the development of degenerative changes of the valve and coronary artery disease and there is an increased risk of developing aneurysms in atherosclerotic altered vessels. Therefore, at the preoperative visit a thorough clinical cardiovascular examination should be performed. Cardiological advice and an examination should be sought from a specialist. For intubation, fibreoptic procedures should be considered. Anaesthetic management and perioperative monitoring are determined by the results of the cardiological examination and the type and extent of the operation.