每日一题_2022.2.23

A 67-year-old, 84-kg (184-lb) man is postoperative day one after exploratory laparotomy for a perforated(穿刺) intestinal viscus with gross spillage（溢出） of bowel contents. His medical history includes hypertension, tobacco abuse, and colon cancer. After localization of the perforation and adequate intra-abdominal washout, his bowels were placed back in continuity and the peritoneum was closed. He remains sedated on mechanical ventilation, and is receiving adequate antimicrobial therapy. He has been adequately resuscitated, weaned off vasoactive medications, and remains on maintenance IV fluids, consisting of Ringer lactated solution, 120 mL/hr.

The use of maintenance IV fluids is associated most with which of the following outcomes?

A. Mortality benefit in the postoperative surgical patient population 

B. Increased length of ventilatory support

C. Reduction in the incidence of acute renal failure

D. Increased association with mortality

答案解析：

液体复苏是危重病医学中普遍存在的干预措施，提供维持液体是该疗法的共同基石。维持液体的基本原理是帮助液体复苏并防止前负荷依赖性低灌注。这一点尚未得到证实。已知约80%的等渗晶体输注液未在血管腔内维持，维持液导致了容量超负荷，容量超负荷越来越被认为是重症患者器官衰竭的直接因素。

血管内循环量对于具有灌注不良或终末器官损害标志物的患者非常重要。似乎存在预防休克和多系统器官衰竭的最佳循环液体量。自由液体策略显示了外周水肿、呼吸衰竭/肺损伤、稀释性贫血和凝血病、中性粒细胞活化、伤口愈合不良和肠道恢复延迟等并发症。应在个体化基础上恢复血管内容量，并注意用于复苏的液体类型和提供的液体量。

References:

1. Myburgh JA and Mythen MG. Resuscitation fluids. N Engl J Med. 2013 Sep 26;369(13):1243-1251.
2. Raghunathan K, Shaw A, Nathanson B, et al. Association between the choice of IV crystalloid and in-hospital mortality among critically ill adults with sepsis. Crit Care Med. 2014 Jul;42(7):1585-1591.
3. Hilton AK, Pellegrino VA, Scheinkestel CD. Avoiding common problems associated with intravenous fluid therapy. Med J Aust. 2008 Nov 3;189(9):509-513.

正确答案：D

补充内容：

• Inappropriate intravenous fluid therapy is a significant cause of patient morbidity and mortality and may result from either incorrect volume (too much or too little) or incorrect type of fluid. 不适当的静脉输液治疗是患者发病和死亡的重要原因，可能由不正确的液体量（过多或过少）或不正确的液体类型引起。
• Fluid overload has no precise definition, but complications usually arise in the context of pre-existing cardiorespiratory disease and severe acute illness.液体超负荷没有精确的定义，但并发症通常发生在既存心肺疾病和重度急性疾病的背景下。
• Insufficient fluid administration is readily identified by signs and symptoms of inadequate circulation and decreased organ perfusion.通过循环不充分和器官灌注减少的体征和症状很容易识别液体给药不足。
• Administration of the wrong type of fluid results in derangement of serum sodium concentration, which, if severe enough, leads to changes in cell volume and function, and may result in serious neurological injury.给予错误类型的液体会导致血清钠浓度紊乱，如果严重到足以导致细胞体积和功能的改变，并可能导致严重的神经损伤。
• In patients whose condition is uncomplicated, we recommend a restrictive approach to perioperative intravenous fluid replacement, with initial avoidance of hypotonic fluids, and regular measurement of serum concentration of electrolytes, especially sodium.在病情无并发症的患者中，我们建议采用限制性方法进行围手术期静脉补液，最初避免低渗液体，并定期测量电解质（尤其是钠）的血清浓度。