Funk Duane, Bohn James, Mutch Wac, Hayakawa Tom, Buchel Edward W
University of Manitoba;
Plast Surg (Oakv). 2015 Winter;23(4):231-4. doi: 10.4172/plastic-surgery.1000937.
Fluid management of the surgical patient has undergone a paradigm shift over the past decade. A change from 'wet' to 'dry' to a 'goal-directed' approach has been witnessed. The fluid management of patients undergoing free flap reconstruction is particularly challenging. This is typically a long operation with minimal surgical stimulation, and hypotension often ensues. The use of vasopressors in these cases is contraindicated to maintain adequate flow to the flap. Hypotension is often treated with intravenous fluid boluses. However, aggressive fluid administration to maintain adequate blood pressure can result in flap edema, venous engorgement and, ultimately, flap loss.
The primary objective of the present study was to determine whether goal-directed fluid therapy, titrated to maintain stroke volume variation ≤13%, with the use of an arterial pulse contour device results in improved postoperative cardiac index (CI) and stroke volume index (SVI) with reduced amounts of intravenous fluid. The primary end points studied were CI, SVI and cumulative crystalloid/colloid administration.
Twenty female patients undergoing simultaneous microvascular free flap reconstruction immediately following mastectomy were studied. Preoperative and intraoperative care were standardized. Each patient received intra-arterial blood pressure monitoring. In all patients, cardiac output measurement occurred throughout the intraoperative period using the arterial pulse contour device. Control patients had their fluid administered at the discretion of the anesthesiologist (blinded to results from the cardiac output device). Patients in the intervention group had a baseline crystalloid infusion of 5 mL/kg/h, with intravenous colloid boluses to maintain a stroke volume variation ≤13%.
There was no difference in heart rate or mean arterial pressure between groups at the end of the operation. However, at the end of the operation, the intervention group had significantly higher mean (± SD) CI (3.8±0.8 L/min/m(2) versus 3.0±0.5 L/min/m(2); P=0.02) and SVI (51.4±2.4 mL/m(2) versus 43.3±2.3 mL/m(2); P=0.03). This improved CI and SVI was achieved with similar amounts of administered intraoperative fluid (5.8±0.5 mL/kg/h versus 5.0±0.7 mL/kg/h, control versus intervention). The intervention group required less postoperative fluid resuscitation during the early postoperative period (total fluid administered from end of operation to midnight of the operative day, 6.4±1.9 mL/kg/h versus 10.2±3.3 mL/kg/h, intervention versus control, respectively, P<0.01).
Goal-directed fluid therapy using minimally invasive cardiac output monitoring resulted in improved end-operative hemodynamics, with less 'rescue' fluid administration during the perioperative period.
在过去十年中，外科患者的液体管理发生了范式转变。见证了从“湿”到“干”再到“目标导向”方法的转变。游离皮瓣重建患者的液体管理尤其具有挑战性。这通常是一台长时间的手术，手术刺激最小，常出现低血压。在这些情况下，使用血管升压药维持皮瓣的充足血流是禁忌的。低血压通常通过静脉推注液体来治疗。然而，积极补液以维持足够的血压可能导致皮瓣水肿、静脉充血，最终导致皮瓣坏死。
本研究的主要目的是确定使用动脉脉搏轮廓装置进行目标导向液体治疗，将每搏量变异度滴定至≤13%，是否能改善术后心脏指数（CI）和每搏量指数（SVI），并减少静脉输液量。研究的主要终点是CI、SVI和晶体液/胶体液的累积用量。
对20例乳房切除术后立即进行同期微血管游离皮瓣重建的女性患者进行研究。术前和术中护理标准化。每位患者均接受动脉血压监测。所有患者在术中全程使用动脉脉搏轮廓装置测量心输出量。对照组患者的液体输注由麻醉医生酌情决定（对心输出量装置的结果不知情）。干预组患者的晶体液基线输注速度为5 mL/kg/h，静脉推注胶体液以维持每搏量变异度≤13%。
手术结束时，两组患者的心率或平均动脉压无差异。然而,手术结束时，干预组的平均（±标准差）CI（3.8±0.8 L/min/m² 对比 3.0±0.5 L/min/m²；P = 0.02）和SVI（51.4±2.4 mL/m² 对比 43.3±2.3 mL/m²；P = 0.03）显著更高。在术中给予相似量的液体（对照组与干预组分别为5.0±0.7 mL/kg/h对比5.8±0.5 mL/kg/h）的情况下，CI和SVI得到了改善。干预组术后早期所需的液体复苏量较少（从手术结束到手术日午夜的总液体输注量，干预组与对照组分别为6.4±1.9 mL/kg/h对比10.2±3.3 mL/kg/h, P<0.01）。
使用微创心输出量监测的目标导向液体治疗可改善手术结束时的血流动力学，围手术期“抢救”性补液量减少。
