Impaired delivery of dialysis: diagnosis and correction

Hemodialysis treatments yielding inadequate amounts of dialysis, as defined by urea kinetic modeling, are partially responsible for considerable mortality and morbidity in the United States. In almost 50% of dialysis treatments resulting in a Kt/V of < 1.0, the culprit is impaired delivery of the prescribed amount of dialysis. The factors involved in impaired delivery of dialysis are many and often elusive. If present and widespread, a search for the cause of the problem entails careful examination of the equipment and nursing procedures. If impaired delivery is a sporadic and infrequent event, a patient-specific investigation should be undertaken. In either circumstance, a clear understanding of the principles and practical aspects of hemodialysis greatly assists the nephrologist as a sleuth.