National Institute of Mental Health and Neurosciences, Bengaluru, Karnataka, India.
J Neurosurg Anesthesiol. 2022 Jan 1;34(1):e52-e56. doi: 10.1097/ANA.0000000000000706.
Severe traumatic brain injury (TBI) results in raised intracranial pressure (ICP). Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is a noninvasive method for the assessment of raised ICP. Manipulation of positive end-expiratory pressure (PEEP) and end-tidal carbon dioxide (ETCO2) are often used to optimize ICP and improve oxygenation in TBI patients. This study evaluated the effects of PEEP and ETCO2 on ONSD and regional cerebral oxygen saturation (rScO2) in patients with acute TBI.
A total of 14 patients (11 males) aged older than 18 years with acute severe TBI were included in this study. ONSD and rScO2 were assessed before and after changes in PEEP from 5 to 10 cm H2O and in ETCO2 from 40 to 30 mm Hg on both pathologic and nonpathologic sides.
Increasing PEEP and reducing ETCO2 resulted in changes in ONSD and rScO2 on both pathologic and nonpathologic sides. On the pathologic side, ONSD and rScO2 were highest with a PEEP of 10 cm H2O:ETCO2 40 mm Hg combination and lowest with PEEP of 5 cm H2O:ETCO2 30 mm Hg (ONSD 5.24±0.49 vs. 4.27±0.36 mm, P<0.001; rScO2 70.7±9.91% vs. 66.3±9.75%, P<0.001); both PEEP and ETCO2 had significant effects on ONSD and rScO2 (P<0.001). On the nonpathologic side, ONSD and rScO2 were highest and lowest with PEEP of 10 cm H2O:ETCO2 40 mm Hg and PEEP of 5 cm H2O:ETCO2 30 mm Hg combinations, respectively (ONSD: 4.93±0.46 vs. 4.02±0.40 mm, P<0.001; rScO2: 74.77±8.30% vs. 70.69±8.12%, P<0.001). ETCO2 had a significant effect on rScO2 (P<0.001), but the impact of PEEP on rScO2 was not statistically significant (P=0.05).
Increasing PEEP resulted in significant increases in ONSD and rScO2, whereas reducing ETCO2 significantly decreased ONSD and rScO2.
严重创伤性脑损伤（TBI）会导致颅内压升高（ICP）。视神经鞘直径（ONSD）的超声测量是评估ICP升高的一种非侵入性方法。在 TBI 患者中，通常会使用调整呼气末正压（PEEP）和呼气末二氧化碳（ETCO2）来优化 ICP 和改善氧合。本研究评估了 PEEP 和 ETCO2 对急性 TBI 患者 ONSD 和局部脑氧饱和度（rScO2）的影响。
本研究共纳入 14 名年龄大于 18 岁的急性重度 TBI 患者（男性 11 名）。在病理性和非病理性侧，分别在 PEEP 从 5 至 10cmH2O 和 ETCO2 从 40 至 30mmHg 变化后，评估 ONSD 和 rScO2。
增加 PEEP 和降低 ETCO2 导致病理性和非病理性侧的 ONSD 和 rScO2 发生变化。在病理性侧，当 PEEP 为 10cmH2O：ETCO2 为 40mmHg 时，ONSD 和 rScO2 最高：ONSD 为 5.24±0.49mm，rScO2 为 70.7±9.91%，而当 PEEP 为 5cmH2O：ETCO2 为 30mmHg 时，ONSD 和 rScO2 最低：ONSD 为 4.27±0.36mm，rScO2 为 66.3±9.75%（P<0.001）；PEEP 和 ETCO2 对 ONSD 和 rScO2 均有显著影响（P<0.001）。在非病理性侧，当 PEEP 为 10cmH2O：ETCO2 为 40mmHg 和 PEEP 为 5cmH2O：ETCO2 为 30mmHg 时，ONSD 和 rScO2 最高和最低，分别为 4.93±0.46mm 和 4.02±0.40mm（P<0.001），rScO2 分别为 74.77±8.30%和 70.69±8.12%（P<0.001）。ETCO2 对 rScO2 有显著影响（P<0.001），但 PEEP 对 rScO2 的影响无统计学意义（P=0.05）。
增加 PEEP 可显著增加 ONSD 和 rScO2，而降低 ETCO2 则可显著降低 ONSD 和 rScO2。
