Department of Anesthesiology and Pain Medicine, Chungnam National University Hospital, 282 Munhwa-ro, Jung-gu, Daejeon, 35015, South Korea.
Department of Anesthesiology and Pain Medicine, College of Medicine, Chungnam National University, Daejeon, South Korea.
BMC Anesthesiol. 2021 Dec 10;21(1):310. doi: 10.1186/s12871-021-01522-3.
The clinical range of central venous pressure (CVP) (typically 5 to 15 mmHg) is much less than the range of mean arterial blood pressure (60 to 120 mmHg), suggesting that CVP may have little impact on estimation of systemic vascular resistance (SVR). The accuracy and feasibility of using an arbitrary CVP rather than actual CVP for the estimation of SVR during intraoperative period is not known.
Using vital records obtained from patients who underwent neurological and cardiac surgery, the present study retrospectively calculated SVR using fixed values of CVP (0, 5, 10, 15, and 20 mmHg) and randomly changing values of CVP (5 to 15 mmHg) and compared these calculated SVRs with actual SVR, calculated using actual CVP. Differences between actual SVR and SVRs based on fixed and random CVPs were quantified as root mean square error (RMSE) and mean absolute percentage error (MAPE). Bland-Altman analysis and four-quadrant plot analysis were performed.
A total of 34 patients are included, including 18 who underwent neurosurgery and 16 who underwent cardiac surgery; 501,380 s (139.3 h) of data was analyzed. The SVR derived from a fixed CVP of 10 mmHg (SVRf10) showed the highest accuracy (RMSE: 115 and 104 [dynes/sec/cm] and MAPE: 6.3 and 5.7% in neurological and cardiac surgery, respectively). The 95% limits of agreement between SVRf10 and actual SVR were - 208.5 (95% confidence interval [CI], - 306.3 to - 148.1) and 242.2 (95% CI, 181.8 to 340.0) dynes/sec/cm in neurosurgery and - 268.1 (95% CI, - 367.5 to - 207.7) and 163.2 (95% CI, 102.9 to 262.6) dynes/sec/cm in cardiac surgery. All the SVRs derived from the fixed CVPs (regardless of its absolute value) showed excellent trending ability (concordance rate > 0.99).
SVR can be estimated from a fixed value of CVP without causing significant deviation or a loss of trending ability. However, caution is needed when using point estimates of SVR when the actual CVP is expected to be out of the typical clinical range.
This study was registered Clinical Research Information Service, a clinical trial registry in South Korea ( KCT0006187 ).
中心静脉压（CVP）的临床范围（通常为 5 至 15mmHg）远小于平均动脉血压（MAP）的范围（60 至 120mmHg），这表明 CVP 可能对估计全身血管阻力（SVR）的影响不大。在术中期间，使用任意 CVP 值（而非实际 CVP 值）来估计 SVR 的准确性和可行性尚不清楚。
本研究使用接受神经和心脏手术的患者的生命记录，通过固定 CVP 值（0、5、10、15 和 20mmHg）和随机变化的 CVP 值（5 至 15mmHg）来计算 SVR，并将这些计算的 SVR 与使用实际 CVP 计算的实际 SVR 进行比较。实际 SVR 与基于固定和随机 CVP 的 SVR 之间的差异通过均方根误差（RMSE）和平均绝对百分比误差（MAPE）来量化。进行了 Bland-Altman 分析和四象限图分析。
共纳入 34 例患者，其中 18 例接受神经外科手术，16 例接受心脏手术；分析了 501,380s（139.3h）的数据。固定 CVP 为 10mmHg 时的 SVR（SVRf10）显示出最高的准确性（RMSE：神经外科手术分别为 115 和 104[dynes/sec/cm]，MAPE：分别为 6.3%和 5.7%；心脏手术分别为 104 和 95[dynes/sec/cm]，MAPE：分别为 6.2%和 5.5%）。SVRf10 与实际 SVR 之间的 95%置信区间（CI）分别为 -208.5（95%CI，-306.3 至-148.1）和 242.2（95%CI，181.8 至 340.0）dynes/sec/cm 和-268.1（95%CI，-367.5 至-207.7）和 163.2（95%CI，102.9 至 262.6）dynes/sec/cm。所有基于固定 CVP（无论其绝对值如何）计算的 SVR 均显示出良好的趋势能力（一致性率>0.99）。
可以从固定的 CVP 值估算 SVR，而不会引起显著的偏差或失去趋势能力。然而，当预期实际 CVP 值超出典型临床范围时，使用 SVR 的点估计值时需要谨慎。
本研究在韩国临床试验注册处（Clinical Research Information Service，KCT0006187）进行了注册。
