Obrador G T, Pereira B J
Division of Nephrology, New England Medical Center, Boston, MA 02111, USA.
Am J Kidney Dis. 1998 Mar;31(3):398-417. doi: 10.1053/ajkd.1998.v31.pm9506677.
The high mortality rate among dialysis patients has spawned investigation into potentially correctable factors that are associated with an increased risk of death. Several studies have demonstrated a strong association between an increased risk of death in dialysis patients and suboptimal delivered dose of dialysis, malnutrition, and non-renal comorbidity. In addition, the use of unsubstituted cellulose dialyzers and reprocessed dialyzers also has been associated with an increased risk of death. Increased attention to these factors has resulted in a significant improvement in patient survival. Nonetheless, the mortality of dialysis patients remains unacceptably high and indicates that other factors may be operative. One of the factors that has thus far received scant attention, but could significantly affect morbidity and mortality in dialysis patients, is the timing and quality of care before initiation of dialysis. Optimal pre-end-stage renal disease care involves early interventions aimed at delaying progression of chronic renal failure, judicious management of uremic complications, timely placement of vascular access, timely initiation of renal replacement therapy, and implementation of educational programs targeted at maximum rehabilitation. Given the fact that early referral to the nephrologist is likely to result in optimal pre-dialysis care, the 1993 National Institutes of Health Consensus Statement on Morbidity and Mortality of Dialysis recommended that referral of a patient to a renal team should occur at a serum creatinine of 1.5 mg/dL in women and 2.0 mg/dL in men. Several investigators also have argued that patients with chronic renal failure who begin dialysis at a relatively "high level of residual renal function" (early start) may have lower morbidity and mortality compared with patients who begin dialysis at a more traditional "low level of renal function" (late start). This hypothesis is based on evidence that declining renal function is associated with malnutrition and that malnutrition at the start of dialysis is associated with poor clinical outcomes. Furthermore, patients are started on dialysis at an endogenous solute clearance that is lower than that accepted as optimum for patients on dialysis. Finally, limited clinical studies have demonstrated the benefit of early initiation of dialysis. Consequently, the Peritoneal Dialysis Adequacy Work Group of the National Kidney Foundation-Dialysis Outcomes Quality Initiative recommends that dialysis be initiated when the weekly renal Kt/Vurea decreases to below 2.0 unless all three of the following criteria are fulfilled: (1) stable or increased edema-free body weight, (2) normalized protein equivalent of total nitrogen appearance greater than 0.8, and (3) absence of clinical symptoms and signs attributable to uremia.
透析患者的高死亡率引发了对可能可纠正因素的调查,这些因素与死亡风险增加相关。多项研究表明,透析患者死亡风险增加与透析剂量未达最佳、营养不良及非肾脏合并症之间存在密切关联。此外,使用未替代纤维素透析器和复用透析器也与死亡风险增加有关。对这些因素的更多关注已使患者生存率显著提高。尽管如此,透析患者的死亡率仍然高得令人难以接受,这表明可能还有其他因素在起作用。迄今为止很少受到关注,但可能对透析患者的发病率和死亡率产生重大影响的因素之一,是开始透析前护理的时机和质量。最佳的终末期肾病前期护理包括旨在延缓慢性肾衰竭进展的早期干预、对尿毒症并发症的明智管理、及时建立血管通路、及时开始肾脏替代治疗,以及实施旨在实现最大程度康复的教育计划。鉴于早期转诊至肾病专家可能会带来最佳的透析前护理,1993年美国国立卫生研究院关于透析发病率和死亡率的共识声明建议,女性患者血清肌酐达到1.5mg/dL、男性患者血清肌酐达到2.0mg/dL时,应将患者转诊至肾脏治疗团队。一些研究人员还认为,与在相对“高残余肾功能水平”(早期开始)时开始透析的慢性肾衰竭患者相比,在更传统的“低肾功能水平”(晚期开始)时开始透析的患者,其发病率和死亡率可能更低。这一假设基于以下证据:肾功能下降与营养不良相关,而透析开始时的营养不良与不良临床结局相关。此外,患者开始透析时的内源性溶质清除率低于公认的透析患者最佳清除率。最后,有限的临床研究已证明早期开始透析的益处。因此,美国国家肾脏基金会透析预后质量倡议组织的腹膜透析充分性工作组建议,当每周肾Kt/Vurea降至2.0以下时开始透析,除非满足以下所有三项标准:(1)无水肿体重稳定或增加;(2)总氮排出量的蛋白质当量正常化大于0.8;(3)无尿毒症所致的临床症状和体征。