Department of Anesthesiology and Pain Medicine, Juntendo University Graduate School of Medicine, 2‑1‑1 Hongo, Bunkyo‑ku, Tokyo, 113‑8421, Japan.
Department of Cardiovascular Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan.
Heart Vessels. 2023 Jun;38(6):839-848. doi: 10.1007/s00380-023-02233-0. Epub 2023 Jan 24.
Cerebral tissue oximetry with near-infrared spectroscopy (NIRS) is used to monitor cerebral oxygenation during cardiac surgery. To date, reduced baseline cerebral NIRS values have been attributed to reduced cerebral blood flow primarily based on a significant positive correlation between left ventricular ejection fraction (LVEF) and baseline rSO measured with the INVOS 5100C oximeter. Reportedly, however, rSO, but not StO measured with the FORESIGHT Elite oximeter, correlated with LVEF. We, thus, investigated associations among baseline NIRS values measured with three different oximeters before anesthesia for cardiac surgery and preoperative transthoracic echocardiography (TTE) variables, including LVEF, to examine whether there are inter-device differences in associations among baseline NIRS values and TTE variables. Using Spearman's correlation coefficient, we retrospectively investigated associations among 15 preoperative TTE variables, including LVEF, and baseline NIRS values, including rSO, StO, and TOI with the NIRO-200NX oximeter in 1346, 515, and 301 patients, respectively. Only rSO (p < 0.00001), but not TOI or StO (p > 0.05), positively correlated with LVEF. On the other hand, baseline rSO, TOI, and StO consistently, negatively correlated with the left atrial diameter index (LADI), early diastolic transmitral flow velocity (E), E-to-early diastolic mitral annular velocity ratio (E/e'), estimated right ventricular systolic pressure (eRVP), and inferior vena cava diameter index (IVCDI) (p < 0.0005 to p < 0.00001). Because all of these five TTE variables could be positively associated with right as well as left ventricular filling pressure, our results indicated that reduced baseline NIRS values were consistently associated not with reduced LVEF but with TTE findings indicative of elevated biventricular filling pressure. Our data suggest that regional venous congestion greatly contributes to reduced baseline NIRS values in patients undergoing cardiac surgery.
脑氧合的近红外光谱（NIRS）组织用于监测心脏手术期间的脑氧合。迄今为止，根据 INVOS 5100C 血氧仪测量的左心室射血分数（LVEF）与基线 rSO 之间存在显著正相关，已将基线脑 NIRS 值降低归因于脑血流减少。然而，据报道，与 LVEF 相关的是 FORESIGHT Elite 血氧仪测量的 rSO，但不是 StO。因此，我们研究了三种不同血氧仪在心脏手术前麻醉期间测量的基线 NIRS 值与术前经胸超声心动图（TTE）变量（包括 LVEF）之间的相关性，以检查基线 NIRS 值与 TTE 变量之间的相关性是否存在设备间差异。使用 Spearman 相关系数，我们回顾性地研究了在 1346、515 和 301 例患者中，包括 LVEF 在内的 15 个术前 TTE 变量与包括 rSO、StO 和 TOI 在内的基线 NIRS 值之间的相关性。只有 rSO（p<0.00001），而不是 TOI 或 StO（p>0.05），与 LVEF 呈正相关。另一方面，基线 rSO、TOI 和 StO 与左心房直径指数（LADI）、舒张早期二尖瓣血流速度（E）、E 与舒张早期二尖瓣环速度比（E/e'）、估计右心室收缩压（eRVP）和下腔静脉直径指数（IVCDI）呈负相关（p<0.0005 至 p<0.00001）。由于所有这五个 TTE 变量都可以与右心室和左心室充盈压呈正相关，我们的结果表明，基线 NIRS 值降低与 LVEF 降低无关，而是与提示双心室充盈压升高的 TTE 发现有关。我们的数据表明，区域性静脉充血极大地导致心脏手术患者基线 NIRS 值降低。
