Optimizing Patient Safety During Hemodialysis

PUBLICATION OF THE LANDMARK REPORT TO ERR IS Human: Building a Safer Health System by the Institute of Medicine galvanized the health care system to focus relentlessly on improving patient safety. These efforts have many forms, often leveraging current health information technology to collect and analyze information about the characteristics of avoidable complications. Many efforts focus on known weaknesses in the health care delivery process, such as discontinuity of care, lack of integrated accountability among clinicians for patient outcomes, and communication errors. Failure mode analysis, root cause analysis, and examination of “near misses” are often tools used for improving patient safety. However, observers agree that there remain fundamental problems with patient safety in an increasingly complex medical environment. The use of hemodialysis for the treatment of irreversible kidney failure represents an important opportunity to improve patient safety. Hemodialysis has gradually been transformed from an extraordinary to a commonplace medical procedure during the past 50 years. Today, more than 50 million hemodialysis treatments are performed annually in the United States alone. Moreover, as dialysis therapy has matured, an increasingly elderly, frail population with extensive comorbidities is now being treated with high attendant risks for procedure-related complications. Meanwhile, technical improvements in nearly all aspects of the hemodialysis procedure have greatly increased overall safety. Today, there is better standardization of equipment, more use of automated controls and real-time monitors built into dialysis equipment for adjusting critical components of the dialysis procedure, and use of higher purity of water in dialysate than in the past. However, many gaps remain in the safety net around this complex medical procedure and current approaches for improving safety in the dialysis population are often suboptimal. Published studies that systematically evaluate the frequency and type of adverse events and medical errors occurring in dialysis units are rare. Many patient safety problems in dialysis units are “known knowns,” including medication errors, risks for intradialytic hypotension, and complications related to vascular access. These problems can be addressed using strategies already proven to have benefit in other clinical settings, such as medication reconciliation, and targeted interventions for prevention of falls. Other safety problems, such as clusters of unusual infections, fit readily into failure mode analysis models. The greatest opportunities and challenges, however, probably involve identifying “unknown unknowns” that affect patient safety. Two salient studies, separated by more than 40 years and each published in JAMA, illustrate the inherent value of alert clinicians and researchers working together to illuminate “unknown unknowns” in dialysis care. In 1968, during the early days of dialysis therapy, clinicians made the serendipitous observation that transient neutropenia occurred 2 to 15 minutes after starting dialysis. The neutropenia was followed by the appearance of circulating immature neutrophils and by the end of dialysis the white blood cell count was normal. The occurrence of severe transient neutropenia during dialysis was then confirmed in 33 consecutive patients undergoing dialysis treatments. The clinicians became investigators and demonstrated that this was a systemic phenomenon by drawing blood samples from the antecubital vein of the contralateral arm (ie, venipuncture in the arm away from the dialysis access site) and further noted that the neutropenia developed when only a small fraction of the blood volume had passed through the dialyzer. Subsequent research clarified that when blood came into contact with dialysis membranes manufactured out of unmodified cellulose, commonly used in that era, vigorous activation of the alternate complement pathway ensued. The transient neutropenia was due to profound complementmediated neutrophil activation, which caused aggregation of neutrophils in tissue beds such as the lungs. When later work established that there were important clinical consequences from repetitive neutrophil activation with each dialysis treatment, new more biocompatible dialysis membranes were developed, and eventually unmodified cellulosic dialyzers were removed from the market.