Department of Anesthesiology, Osaka City General Hospital and Children Hospital, 2-13-22 Miyakojima-hondori, Miyakojimaku, Osaka, Osaka, 534-0021, Japan.
J Anesth. 2011 Jun;25(3):345-9. doi: 10.1007/s00540-011-1136-1. Epub 2011 Apr 12.
Single-lung ventilation (SLV) is thought to reduce regional cerebral oxygen saturation (rSO(2)). In this study, we evaluated changes in rSO(2) during SLV and their correlation with perioperative changes in cognitive function.
Sixty-nine patients participated in this study, each of whom received combined thoracic epidural and general anesthesia. rSO(2) was measured using INVOS 5100 (Somanetics, Troy, MI, USA) before anesthesia (baseline value) and until SLV was completed. Patient cognitive function was assessed using the mini mental state examination (MMSE) on the day before surgery (baseline) and then repeated 4 days after surgery. The patients were classified into two groups: with (desaturation group, group D) and without (nondesaturation group, group N) cerebral desaturation during SLV. Cerebral desaturation was defined as a reduction of rSO(2) during SLV less than 80% of the baseline value. An intergroup comparison was made between perioperative cognitive function findings (MMSE score change between baseline and 4th day after surgery). We also examined the correlation between the duration of desaturation during SLV and perioperative MMSE score changes in group D patients.
Seventeen patients were included in group D. The MMSE score decrease was significantly higher in group D as compared to that in group N (P < 0.05). The duration of desaturation time was significantly negatively correlated with MMSE score change (r(2) = 0.444, P < 0.05).
Duration of cerebral desaturation time during SLV correlates with MMSE score. Additional studies are needed to determine whether intervention against cerebral desaturation during SLV can prevent postoperative cognitive dysfunction.
单肺通气（SLV）被认为会降低局部脑氧饱和度（rSO₂）。在这项研究中，我们评估了 SLV 期间 rSO₂的变化及其与围手术期认知功能变化的相关性。
69 名患者参与了这项研究，他们均接受了胸段硬膜外联合全身麻醉。在麻醉前（基础值）和 SLV 完成之前，使用 INVOS 5100（Somanetics，密歇根州特洛伊）测量 rSO₂。在手术前一天（基础）使用简易精神状态检查（MMSE）评估患者的认知功能，然后在手术后 4 天重复评估。将患者分为两组：SLV 期间有（脑缺氧组，D 组）和无（无脑缺氧组，N 组）脑缺氧。脑缺氧定义为 SLV 期间 rSO₂降低至基础值的 80%以下。对围手术期认知功能发现（手术前后 MMSE 评分变化）进行组间比较。我们还检查了 D 组患者 SLV 期间缺氧时间与围手术期 MMSE 评分变化之间的相关性。
17 名患者纳入 D 组。与 N 组相比，D 组的 MMSE 评分下降明显更高（P < 0.05）。缺氧时间与 MMSE 评分变化呈显著负相关（r²=0.444，P < 0.05）。
SLV 期间脑缺氧时间与 MMSE 评分相关。需要进一步的研究来确定针对 SLV 期间脑缺氧的干预是否可以预防术后认知功能障碍。
