BACKGROUND Fluid overload is a risk factor for morbidity, mortality, and prolonged ventilation time after surgery. Patients on maintenance hemodialysis might be at higher risk. We hypothesized that fluid accumulation would be directly associated with extended ventilation time in patients on hemodialysis, as compared to patients with chronic kidney disease not on dialysis (CKD3-4) and patients with normal renal function (reference group). METHODS This is a prospective observational study that included patients submitted to isolated and elective coronary artery bypass surgery, divided in 3 groups according to time on mechanical ventilation: < 24 h, 24-48 h and > 48 h. The same observer followed patients daily from the surgery to the hospital discharge. Cumulative fluid balance was defined as the sum of daily fluid balance over the first 5 days following surgery. RESULTS Patients requiring more than 48 h of ventilation (5.3%) had a lower estimated glomerular filtration rate, were more likely to be on maintenance dialysis, had longer anesthesia time, needed higher dobutamine and noradrenaline infusion following surgery, and had longer hospitalization stay. Multivariate analysis revealed that the fluid accumulation, scores of sequential organ failure assessment in the day following surgery, and the renal function (normal, chronic kidney disease not on dialysis and maintenance hemodialysis) were independently associated with time in mechanical ventilation. Among patients on hemodialysis, the time from the surgery to the first hemodialysis session also accounted for the time on mechanical ventilation. CONCLUSIONS Fluid accumulation is an important risk factor for lengthening mechanical ventilation, particularly in patients on hemodialysis. Future studies are warranted to address the ideal timing for initiating dialysis in this scenario in an attempt to reduce fluid accumulation and avoid prolonged ventilation time and hospital stay.

中文翻译：

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维持性血液透析患者冠状动脉搭桥术后液体超负荷与机械通气时间延长有关。

背景技术液体超负荷是发病率，死亡率和手术后通风时间延长的危险因素。维持性血液透析患者的风险可能更高。我们假设与没有透析的慢性肾脏疾病患者（CKD3-4）和肾功能正常的患者（参考组）相比，血液透析患者的积液与通气时间的延长直接相关。方法这是一项前瞻性观察性研究，纳入了接受单独和择期冠状动脉搭桥手术的患者，根据机械通气时间将其分为3组：<24 h，24-48 h和> 48 h。从手术到出院，每天由同一位观察者随访患者。累积体液平衡定义为手术后前5天内每日体液平衡的总和。结果通气时间超过48小时的患者（5.3％）的肾小球滤过率估计值较低，更可能接受维持透析，麻醉时间更长，术后需要更高的多巴酚丁胺和去甲肾上腺素输注，住院时间更长。多变量分析显示，液体积聚，术后第二天器官功能衰竭评估分数以及肾功能（正常，慢性肾病不在透析和维持性血液透析中）均与机械通气时间相关。在接受血液透析的患者中，从手术到第一次血液透析的时间也占机械通气时间。结论积液是延长机械通气的重要危险因素，尤其是在血液透析患者中​​。因此，有必要进行进一步的研究以解决这种情况下开始透析的理想时机，以减少积液并避免延长通气时间和住院时间。