Department of Anesthesiology, University of Virginia Health Sciences Center, Charlottesville, VA 22908-0710, USA.
J Clin Monit Comput. 2012 Oct;26(5):393-400. doi: 10.1007/s10877-012-9390-9. Epub 2012 Aug 19.
Commonly used arterial respiratory variation metrics are based on mathematical analysis of arterial waveforms in the time domain. Because the shape of the arterial waveform is dependent on the site at which it is measured, we hypothesized that analysis of the arterial waveform in the frequency domain might provide a relatively site-independent means of measuring arterial respiratory variation. Radial and femoral arterial blood pressures were measured in nineteen patients undergoing liver transplantation. Systolic pressure variation (SPV), pulse pressure variation (PPV), area under the curve variation (AUCV), and mean arterial pressure variation (MAPV) at radial and femoral sites were calculated off-line. Two metrics, "Spectral Peak Ratio" (SPeR) and "Spectral Power Ratio" (SPoR) based on ratios of the spectral peak and spectral area (power) at the respiratory and cardiac frequencies, were calculated at both radial and femoral sites. Variance among radial-femoral differences was compared and correlation coefficients describing the relationship between respiratory variation at the radial and femoral sites were developed. The variance in radial-femoral differences were significantly different (p < 0.001). The correlation between radial and femoral estimates of respiratory variation were 0.746, 0.658, 0.858, 0.882, 0.941, and 0.925 for SPV, PPV, AUCV, MAPV, SPeR, and SPoR, respectively. Assuming a PPV treatment threshold of 12 % (or equivalent), differences in treatment decisions based on radial or femoral estimates would arise in 12, 14, 5.4, 5.7, 4.8, and 5.5 % of minutes for SPV, PPV, AUCV, MAPV, spectral peak ratio, and spectral power ratio, respectively. As compared to frequency domain-based estimates of respiratory variation, SPV and PPV are relatively dependent on the anatomic site at which they are measured. Spectral peak and power ratios are relatively site-independent means of measuring respiratory variation, and may offer a useful alternative to time domain-based techniques.
常用的动脉呼吸变化指标是基于对动脉波形在时域中的数学分析。由于动脉波形的形状取决于测量的部位，我们假设对动脉波形进行频域分析可能提供一种相对不依赖于部位的测量动脉呼吸变化的方法。对 19 例接受肝移植的患者进行桡动脉和股动脉血压测量。离线计算桡动脉和股动脉的收缩压变化（SPV）、脉压变化（PPV）、曲线下面积变化（AUCV）和平均动脉压变化（MAPV）。在桡动脉和股动脉部位计算了基于呼吸和心脏频率的频谱峰值和频谱面积（功率）比值的两个指标，即“频谱峰值比”（SPeR）和“频谱功率比”（SPoR）。比较了桡动脉-股动脉差异的方差，并得出了描述桡动脉和股动脉呼吸变化之间关系的相关系数。桡动脉-股动脉差异的方差差异有统计学意义（p<0.001）。桡动脉和股动脉估计的呼吸变化之间的相关性分别为 0.746、0.658、0.858、0.882、0.941 和 0.925，用于 SPV、PPV、AUCV、MAPV、SPeR 和 SPoR。假设 PPV 治疗阈值为 12%（或等效），则基于桡动脉或股动脉估计值的治疗决策差异将分别出现在 SPV、PPV、AUCV、MAPV、频谱峰值比和频谱功率比的 12、14、5.4、5.7、4.8 和 5.5%的分钟数中。与基于频域的呼吸变化估计相比，SPV 和 PPV 相对依赖于它们被测量的解剖部位。频谱峰值和功率比是测量呼吸变化的相对不依赖于部位的方法，并且可能为基于时域的技术提供有用的替代方法。
