Mathis Michael R, Schechtman Samuel A, Engoren Milo C, Shanks Amy M, Thompson Aleda, Kheterpal Sachin, Tremper Kevin K
From the Department of Anesthesiology at the University of Michigan Health System, Ann Arbor, Michigan.
Anesthesiology. 2017 Feb;126(2):249-259. doi: 10.1097/ALN.0000000000001460.
Assessment of need for intravascular volume resuscitation remains challenging for anesthesiologists. Dynamic waveform indices, including systolic and pulse pressure variation, are demonstrated as reliable measures of fluid responsiveness for mechanically ventilated patients. Despite widespread use, real-world reference distributions for systolic and pulse pressure variation values have not been established for euvolemic intraoperative patients. The authors sought to establish systolic and pulse pressure variation reference distributions and assess the impact of modifying factors.
The authors evaluated adult patients undergoing general anesthetics for elective noncardiac surgery. Median systolic and pulse pressure variations during a 50-min postinduction period were noted for each case. Modifying factors including body mass index, age, ventilator settings, positioning, and hemodynamic management were studied via univariate and multivariable analyses. For systolic pressure variation values, effects of data entry method (manually entered vs. automated recorded) were similarly studied.
Among 1,791 cases, per-case median systolic and pulse pressure variation values formed nonparametric distributions. For each distribution, median values, interquartile ranges, and reference intervals (2.5th to 97.5th percentile) were, respectively, noted: these included manually entered systolic pressure variation (6.0, 5.0 to 7.0, and 3.0 to 11.0 mmHg), automated systolic pressure variation (4.7, 3.9 to 6.0, and 2.2 to 10.4 mmHg), and automated pulse pressure variation (7.0, 5.0 to 9.0, and 2.0 to 16.0%). Nonsupine positioning and preoperative β blocker were independently associated with altered systolic and pulse pressure variations, whereas ventilator tidal volume more than 8 ml/kg ideal body weight and peak inspiratory pressure more than 16 cm H2O demonstrated independent associations for systolic pressure variation only.
This study establishes real-world systolic and pulse pressure variation reference distributions absent in the current literature. Through a consideration of reference distributions and modifying factors, the authors' study provides further evidence for assessing intraoperative volume status and fluid management therapies.
对麻醉医生而言，评估血管内容量复苏的必要性仍然具有挑战性。动态波形指标，包括收缩压和脉压变异，已被证明是机械通气患者液体反应性的可靠指标。尽管已广泛应用，但对于术中血容量正常的患者，尚未建立收缩压和脉压变异值的实际参考分布。作者试图建立收缩压和脉压变异的参考分布，并评估修正因素的影响。
作者评估了接受全身麻醉的择期非心脏手术成年患者。记录每例患者诱导后50分钟内的收缩压和脉压变异中位数。通过单因素和多因素分析研究包括体重指数、年龄、呼吸机设置、体位和血流动力学管理等修正因素。对于收缩压变异值，同样研究了数据录入方法（手动录入与自动记录）的影响。
在1791例病例中，每例患者的收缩压和脉压变异中位数形成非参数分布。对于每种分布，分别记录了中位数、四分位间距和参考区间（第2.5至97.5百分位数）：这些包括手动录入的收缩压变异（6.0、5.0至7.0和3.0至11.0 mmHg）、自动记录的收缩压变异（4.7、3.9至6.0和2.2至10.4 mmHg）以及自动记录的脉压变异（7.0、5.0至9.0和2.0至16.0%）。非仰卧位和术前使用β受体阻滞剂与收缩压和脉压变异改变独立相关，而潮气量超过理想体重8 ml/kg和吸气峰压超过16 cm H2O仅与收缩压变异存在独立关联。
本研究建立了当前文献中缺乏的实际收缩压和脉压变异参考分布。通过考虑参考分布和修正因素，作者的研究为评估术中容量状态和液体管理治疗提供了进一步的证据。
