Khanasuk Yutthana, Tanavalee Aree
J Med Assoc Thai. 2015 Jan;98 Suppl 1:S42-8.
Low urine output (LUO) for six hours is defined as the stage that is at risk of acute renal failure. Major surgeries with a bloodless field, such as total knee arthroplasty (TKA), may be associated with LUO; however; there has been no study addressing this point. The present study evaluated the incidence of LUO and the effect of fluid balance on LUO in TKA patients during the first 24 hours after surgery.
The authors retrospectively evaluated 257 uncomplicated patients undergoing unilateral TKA during the first 24 hours after surgery. Patients' demographic data, intra-operative intravenous (IV) fluid replacement, postoperative IV fluid replacement, oral fluid intake, total fluid intake, postoperative urine output, blood collected from the drain, and the total visible fluid output during the first 24 hours after surgery were collected and evaluated.
The incidence of LUO was 19.1% (49/257) in the studied group. There were no significant differences in patients' demographic data between the LUO and normal urine output (NUO) groups. Comparing the LUO and NUO groups, the LUO group had a lower volume of intra-operative fluid replacement, with statistical significance. There were no differences in postoperative IV fluid replacement and postoperative oral fluid intake between groups. Although 80.5% of the studied group had LV fluid replacement at a less than ideal level, at discharge there was no patient suffering from renal complications related to LUO.
Urine output is one of the common monitoring parameters of fluid balance in the perioperative period; it should be ≥ 0.5 mL/kg/h. Prolonged low urine output for six hours and for 12 hours are categorized as causing risk and injury to the kidney, respectively. The incidence of LUO at our institution during the first 24 hours after TKA is not uncommon and is significantly related to intra-operative fluid replacement. Fortunately, all LUO patients had further fluid replacement, resulting in no renal complications at discharge. As eighty percent of patients had less than ideal fluid replacement, and patients having LUO during the first 24 hours had a significantly lower volume of intra-operative fluid replacement, the authors propose reconsidering perioperative fluid replacement in TKA patients, especially intra-operative IV fluid to avoid LUO.
6小时低尿量被定义为处于急性肾衰竭风险的阶段。诸如全膝关节置换术（TKA）等无血手术区域的大手术可能与低尿量相关；然而，尚无研究涉及这一点。本研究评估了TKA患者术后24小时内低尿量的发生率以及液体平衡对低尿量的影响。
作者回顾性评估了257例单侧TKA术后24小时内的非复杂性患者。收集并评估了患者的人口统计学数据、术中静脉输液量、术后静脉输液量、口服液体摄入量、总液体摄入量、术后尿量、引流管引流量以及术后24小时内的总可见液体排出量。
研究组中低尿量的发生率为19.1%（49/257）。低尿量组和正常尿量组患者的人口统计学数据无显著差异。比较低尿量组和正常尿量组，低尿量组术中补液量较少，具有统计学意义。两组术后静脉补液量和术后口服液体摄入量无差异。尽管研究组中80.5%的患者液体补充未达到理想水平，但出院时无患者因低尿量出现肾脏并发症。
尿量是围手术期液体平衡的常见监测参数之一；应≥0.5 mL/kg/h。持续6小时和12小时的低尿量分别被归类为对肾脏造成风险和损伤。我院TKA术后24小时内低尿量的发生率并不罕见，且与术中补液量显著相关。幸运的是，所有低尿量患者均接受了进一步补液，出院时无肾脏并发症。由于80%的患者补液未达到理想水平，且术后24小时内出现低尿量的患者术中补液量显著较低，作者建议重新考虑TKA患者的围手术期补液，尤其是术中静脉补液，以避免低尿量。
