补液是STEC-HUS并发症的最重要预防手段

俄勒冈州波特兰——俄勒冈健康与科学大学的小儿肾脏病学专家David Rozansky医生在北太平洋儿科学会(NPPS)2013年会上报告，充分的静脉补液是预防产志贺毒素大肠杆菌溶血性尿毒综合征(STEC-HUS)的肾脏和其他并发症的最重要干手段。

“毫无疑问，假如以避免少尿为目标，则我们都希望能维持充分水合——等容量或略多于等容量，甚至达到轻度血容量过多。即使稍微液体超负荷也没有大碍，因为我们能够在必要时排除这些液体。”

David Rozansky医生

尽管尚不清楚为什么补液在STEC-HUS的治疗中如此重要，但已有多项研究证实了这一现象(Pediatr. Nephrol. 2012;27:1407-10)。与此同时，志贺毒素和替代性补体通路抗体正在研发过程中，或许将给STEC-HUS带来更多靶向性治疗选择。例如抗补体抗体eculizumab在2011年德国疫情中似乎发挥了一定作用，一项法国研究显示该药促进了3例中枢神经系统受累的幼儿病情好转(N. Engl. J. Med. 2011;364:2561-63)。

到目前为止，STEC-HUS仍以支持治疗为主，以透析来处理肾脏问题，以血浆置换来应对中枢神经受累。营养也非常重要。“假如患者开始出现病情恶化并有结肠炎，我会尽可能迅速建立通道进行营养支持。当患者发生肾脏衰竭时，由于急性期严重腹泻，他们几乎都已经饿了4天以上，甚至已持续1周或更长时间无法获得足够营养。”

应避免使用止泻药，以免妨碍患者排出体内的病原微生物。“据我了解，很少有儿科医生使用或推荐止泻药，而治疗、照护成人的医务人员则不然。”与此相似，还应避免使用抗生素，以免加剧肾脏问题。使用抗生素最常见于“怀疑发生了穿孔或即将发生穿孔”的情况下。

Rozansky医生表示，通常会避免输浓缩红细胞，除非血红蛋白水平跌至6 g/dl左右。“当血红蛋白下降如此严重时，血液动力学和使器官获得良好灌注就成为了重要问题。”

“假如怀疑出现了HUS疫情，应迅速将患者转至三级医院。我曾见过1例患者，在没有病情加重迹象的情况下，在与急诊医生交谈后3 h内死于中枢神经系统问题。”

Rozansky医生报告称无相关利益冲突。

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By: M. ALEXANDER OTTO, Internal Medicine News Digital Network

PORTLAND, ORE. – Adequate intravenous hydration is the single most important intervention to prevent renal and other complications from Shiga-toxin–producing Escherichia coli hemolytic-uremic syndrome, according to Dr. David Rozansky, a pediatric nephrologist at the Oregon Health and Science University in Portland.

"It is without a doubt true in my mind that you want to maintain adequate intravenous hydration – euvolemia or slightly better than euvolemia, even modest hypervolemia – if avoidance of oliguria is the goal. I’m okay if a patient gets a little bit fluid overloaded because I can take that fluid off" if necessary, he said at the North Pacific Pediatric Society scientific conference.

Although it remains unclear why hydration is so important in Shiga-toxin–producing E. coli hemolytic-uremic syndrome (STEC-HUS), the point’s been proven in several studies. "From an outcome standpoint, [maintaining hydration] is what you want to do," Dr. Rozansky said (Pediatr. Nephrol. 2012;27:1407-10).

Meanwhile, Shiga toxin and alternate complement pathway antibodies are in development for STEC-HUS and may offer more targeted treatment options. One, the anticomplement antibody eculizumab seemed to be of some help in a 2011 German outbreak; it also seemed to turn around three young children with CNS involvement in a French case series (N. Engl. J. Med. 2011;364:2561-63).

For now, care remains largely supportive and dialysis for renal problems and pheresis for CNS involvement. Nutrition is critical, as well. "If a patient starts going south and has colitis, I get a line in them as quickly as possible and give them nutrition. By the time they are in renal failure, almost every patient has [had] a minimum of four days and usually up to a week or more of essentially starvation, because they’ve been having terrible diarrhea in the acute phase and weren’t getting adequate nutrition," Dr. Rozansky said.

Antidiarrheals should be avoided; they’ll prevent the body from flushing out the organism. "It has been my experience that very few pediatricians prescribe or suggest antidiarrheal medications, [but] I don’t always see that with people who take care of adults and [children]," he said.

Similarly, antibiotics should be avoided because they may make renal problems worse. They come into play mostly if "you suspect a perforation or an impending perforation." In those cases, "you give the antibiotics and you deal with the consequences of renal failure because you are saving the patient’s life," he said.

Dr. Rozansky generally holds off on packed red blood cell transfusions until hemoglobins fall to about 6 g/dL. "At that point, I think the hemodynamics and the ability to get good perfusions to the organs becomes" an issue. "I haven’t seen someone recommend a particular number; most of the colleagues I’ve worked with" transfuse "somewhere between 6 and 7 g/dL," he said.

"If you suspect an HUS outbreak, get [patients] to a tertiary care center quickly. I’ve seen patients who were talking to an ER physician die within 3 hours because of a CNS problem. There’s no worse feeling," he said.

Dr. Rozansky said he has no disclosure.