van Bommel E F H
Department of Internal Medicine, Albert Schweitzer Hospital, PO Box 444, 3300 AK Dordrecht, The Netherlands.
Neth J Med. 2003 Aug;61(8):239-48.
The introduction and development of continuous renal replacement therapy (CRRT) represents one of the most substantial changes in patient management on the intensive care unit (ICU). Several issues, however, are still unresolved. Adequacy of dialysis in critically ill patients involves more than simple control of urea (although considered reflective of toxic uraemic compounds). It also concerns various (other) biochemical and clinical parameters. This article addresses important questions such as the different aspects of 'adequate' dialysis and its timing and intensity ('dialysis dosing'). Dialytic treatment should now be tailored to the patient, influenced by patient characteristics, urgency of treatment, haemodynamic tolerance and vascular access. For this, intermittent haemodialysis and CRRT should be regarded as complementary techniques, to be used interchangeably in critically ill patients with acute renal failure (ARF) according to circumstances. While awaiting scientific criteria for the initiation of renal replacement therapy in ARF patients, it seems reasonable to prefer prevention of physiological derangements to their post-hoc correction. This would mean early initiation of dialytic treatment as renal support rather than its initiation as renal replacement therapy for uraemic complications. The amount of dialysis ('dialysis dose') should preferably be prescribed on an individualised basis, especially when considering that the delivered dialysis dose may make a difference. Despite its limitations, simplified urea kinetic modelling, as outlined in this article's appendix, may be used as a bedside method to establish the required dose with CRRT. If not, at least the weight-adjusted ultrafiltration (UF) flow rate should be used as a surrogate for the prescribed dialysis dose (i.e., ml/kg/h). As the prescribed dialysis dose is usually less than the delivered dose, this should also be taken into account. In addition, nutrition should be viewed as an integral part of the dialysis prescription. Continuing effort should be made to develop 'evidence-based' guidelines for the appropriate prescription and delivery of renal replacement therapy to treat ARF in the ICU. This should include efforts to determine a validated dialysis dose methodology in ARF patients to address further the dose/outcome relationship. Based on existing data, some guidelines for the prescription and delivery of adequate (C)RRT are provided.
连续性肾脏替代治疗（CRRT）的引入和发展代表了重症监护病房（ICU）患者管理方面最重大的变革之一。然而，仍有几个问题尚未解决。重症患者的透析充分性不仅仅涉及简单的尿素控制（尽管尿素被认为可反映毒性尿毒症化合物）。它还涉及各种（其他）生化和临床参数。本文探讨了一些重要问题，如“充分”透析的不同方面及其时机和强度（“透析剂量”）。现在，透析治疗应根据患者情况进行调整，受患者特征、治疗紧迫性、血流动力学耐受性和血管通路的影响。为此，间歇性血液透析和CRRT应被视为互补技术，在急性肾衰竭（ARF）的重症患者中根据情况交替使用。在等待ARF患者开始肾脏替代治疗的科学标准时，优先预防生理紊乱而非事后纠正似乎是合理的。这意味着早期开始透析治疗作为肾脏支持，而不是作为尿毒症并发症的肾脏替代治疗开始。透析量（“透析剂量”）最好根据个体情况规定，特别是考虑到实际给予的透析剂量可能会有所不同。尽管有其局限性，但如本文附录所述的简化尿素动力学模型可作为一种床旁方法来确定CRRT所需的剂量。如果不行，至少应使用体重调整后的超滤（UF）流速作为规定透析剂量的替代指标（即毫升/千克/小时）。由于规定的透析剂量通常小于实际给予的剂量，这一点也应予以考虑。此外，营养应被视为透析处方的一个组成部分。应继续努力制定“基于证据”的指南，以适当处方和实施肾脏替代治疗来治疗ICU中的ARF。这应包括努力确定ARF患者中经过验证的透析剂量方法，以进一步解决剂量/结局关系。基于现有数据，提供了一些关于适当的（C）RRT处方和实施的指南。
