Turk J Med Sci. 2018 Oct 31;48(5):980-984. doi: 10.3906/sag-1803-132.
Background/aim: The aim of this study was to evaluate changes in intracranial pressure following tourniquet deflation using noninvasive ultrasonographic optic nerve sheath diameter (ONSD) measurements. Materials and methods: Our study included 59 adult patients between the ages of 18 and 65 years from the American Society of Anesthesiologists (ASA) I/II risk groups who were scheduled to undergo elective orthopedic surgery of the lower extremities using a tourniquet under general anesthesia. ONSD and end-tidal CO2 (ETCO2) were measured 5 times: 15 min prior to the anesthesia induction; just prior to the deflation of the tourniquet; and at 5, 10, and 15 min after the deflation. Additionally, age, sex, weight, height, ASA score, and duration of operation and tourniquet usage were recorded. Results: The ONSD value measured 5 min after the deflation was significantly higher than all of the remaining measurements. There was a significant correlation between the ONSD and ETCO2 measurements at 5 and 10 min after deflation (r = 0.61, 95% CI 0.42-0.75, P < 0.0001 and r = 0.30, 95% CI 0.04-0.51, P < 0.05, respectively). Conclusion: The ultrasonographic ONSD measurements, which were obtained using a simple and noninvasive approach, increased significantly following tourniquet deflation, and this increase was correlated with an increase in ETCO2.
背景/目的：本研究旨在通过非侵入性视神经鞘直径（ONSD）超声测量评估止血带放气后颅内压的变化。
我们的研究纳入了 59 名年龄在 18 至 65 岁之间、ASA 分级 I/II 的择期行下肢骨科手术的全麻患者。在麻醉诱导前 15 分钟、止血带放气前、放气后 5、10 和 15 分钟，测量 ONSD 和呼气末二氧化碳（ETCO2）5 次。同时记录患者的年龄、性别、体重、身高、ASA 评分、手术和止血带使用时间。
放气后 5 分钟测量的 ONSD 值明显高于其余所有测量值。放气后 5 分钟和 10 分钟时，ONSD 与 ETCO2 测量值之间存在显著相关性（r = 0.61，95%CI 0.42-0.75，P < 0.0001 和 r = 0.30，95%CI 0.04-0.51，P < 0.05）。
采用简单、非侵入性方法获得的超声 ONSD 测量值在止血带放气后显著增加，且与 ETCO2 增加相关。
