Introduction

Abstract

The last 20 years have seen major changes in the practice of critical care medicine. Initially sustained by emerging mechanical ventilation technology and the part-time dedication of interested anesthesiologists, it has gone on to become an established feature of all tertiary institutions, with dedicated and trained specialists, an expanding specific knowledge base, and ongoing research unique to its needs. Critical care medicine is now a well-established medical specialty with specific therapies, publications, practical and cognitive skills, and procedures. The development of intensive care units in particular has had major implications for the kind of surgery that can be performed routinely (such as coronary artery by-pass surgery) and for the type of patients (older and with significant chronic diseases) who can be successfully treated. The evolution of critical care medicine has also had significant implications for clinical nephrologists. One major development has to do with the nature, epidemiology, and management of severe acute renal failure (ARF). Severe ARF is now profoundly different in its epidemiology and associations from the disease seen by nephrologists 30 years ago. It is now seen predominantly in intensive care units, is usually associated with the dysfunction of other organs, and is often accompanied by sepsis. It is typically multifactorial, and has a very high mortality rate. The management of this type of ARF demands the application of complex knowledge and skills. Such knowledge and skills can come either from only a multidisciplinary approach in which nephrologist and intensivist work side by side to achieve optimal care for a given patient, or only from specialists originally from either field who have gone on to formally acquire training and expertise in both specialties. The time has come for the formal development of a specialty area called “Critical Care Nephrology.” The foundation for such an integrated approach has been hemofiltration therapy. Although originally developed to treat patients with end-stage renal disease, hemofiltration has rapidly grown as an important treatment for acute patients. From the original description of Peter Kramer in 1977 as a possible alternative to established techniques, today hemofiltration is a first choice technique for several clinical conditions, particularly multiple organ failure. The success of this technique, however, relies on a strong collaboration between the nephrologist and the intensive care specialist. There are important clinical reasons for collaborative care. Patients with renal failure are significantly more complex than 30 years ago. They almost always are elderly, have significant comorbidity, and have dysfunction of multiple organs. Renal failure cannot be viewed as a simple problem that will get better over time once the initial insult is gone and sufficient renal replacement therapy has been provided. Insights into such renal replacement therapy now reveal that the therapy itself may make a great deal of difference in the course of the disease. The use of continuous renal replacement therapy (CRRT) has partly redefined the indications for initiating dialytic therapy in the intensive care unit. It has expanded the possible role of blood purification in the management of critically ill patients, and it has widened the scope of interaction between the expertise of the nephrologist, the needs of the intensive care specialist, and their common goals for patient recovery. Critically ill patients keep dying at unacceptably high rates. Surely the answer to such a high mortality rate must be that physicians need to combine knowledge and expertise, be modest and collegial, and be constructive, nonconflictual, and interdisciplinary in their approach to patient care. In this issue of Kidney International, we collected the contributions presented as review and original articles at the Fourth International Congress on Hemofiltration held in Darmstadt, Germany on May 14th and 15th, 1999. The aim of this issue is to provide the scientific community with some of the latest contributions in the field of hemofiltration and multiple organ failure, providing a balanced mix between established knowledge and the newer results from clinical trials and basic research. We were able to assemble a group of outstanding scientists and clinicians who are actively involved in the treatment of critically ill patients with multiple organ failure. We hope this Supplement issue will serve as a tool for consultation and informative reading not only for experts, but also for the beginners of this field. We are grateful to our major sponsor, Hospal (Lyon, France), for supporting this meeting. We also appreciate the following sponsors: Baxter (McGaw Park, Illinois, USA), Braun (Melsungen, Germany), Fresenius Medical Care (Bad Homburg, Germany), Hoechst Marion Roussel (Bad Soden, Germany), Janssen-Cilag (Neuss, Germany), Ray-Med (Wiesbaden, Germany), and A. Schulz Lauterbach (Iserlohn, Germany).