目的:探讨不同通气策略对全身麻醉俯卧位脊柱手术患者眼压和颅内压的影响。
方法:72例患者于11月之间在全身麻醉下接受俯卧脊柱手术,2022年6月,2023年平均随机分为两组,接受常规通气(Vt为8mL/kg,Fr为12-15/min,和ETCO2保持在35-40mmHg)或小潮气量换气过度(Vt为6mL/kg,Fr为18-20/min,在手术过程中,etCO2保持在30-35mmHg)。双眼眼压(用手持眼压计测量)视神经鞘直径(ONSD;用床边实时超声在眼球后面3毫米处测量),麻醉前(T0)记录患者的循环和呼吸参数,麻醉诱导后立即(T1),俯卧定位后立即(T2),在操作期间2小时(T3),术后即刻仰卧位(T4)和术后30分钟(T5)。
结果:与T1时相比,两组在T3和T4时IOP和ONSD均显着增加(P<0.05)。在T3和T4时,过度通气组的眼压明显低于常规通气组(P<0.05)。在T4时,过度通气组的ONSD显着降低(P<0.05)。在T3(r=-0.248,P<0.001)和T4(r=-0.251,P<0.001)时,眼压与手术时间长度呈正相关(r=0.779,P<0.001),与术中etco2呈负相关。ONSD仅与手术时间相关(r=0.561,P<0.05),与眼压无关(T3时r=0.178,P>0.05;T4时r=0.165,P>0.05)。
结论:小潮气量过度通气可以减轻全身麻醉下俯卧脊柱手术时IOP和ONSD的增加。
OBJECTIVE: To investigate the effects of different ventilation strategies on intraocular pressure (IOP) and intracranial pressure in patients undergoing spinal surgery in the prone position under general anesthesia.
METHODS: Seventy-two patients undergoing prone spinal surgery under general anesthesia between November, 2022 and June, 2023 were equally randomized into two groups to receive routine ventilation (with Vt of 8mL/kg, Fr of 12-15/min, and etCO2 maintained at 35-40 mmHg) or small tidal volume hyperventilation (Vt of 6 mL/kg, Fr of18-20/min, and etCO2 maintained at 30-35 mmHg) during the surgery. IOP of both eyes (measured with a handheld tonometer), optic nerve sheath diameter (ONSD; measured at 3 mm behind the eyeball with bedside real-time ultrasound), circulatory and respiratory parameters of the patients were recorded before anesthesia (T0), immediately after anesthesia induction (T1), immediately after prone positioning (T2), at 2 h during operation (T3), immediately after supine positioning after surgery (T4) and 30 min after the operation (T5).
RESULTS: Compared with those at T1, IOP and ONSD in both groups increased significantly at T3 and T4(P < 0.05). IOP was significantly lower in hyperventilation group than in routine ventilation group at T3 and T4(P < 0.05), and ONSD was significantly lower in hyperventilation group at T4(P < 0.05). IOP was positively correlated with the length of operative time (r=0.779, P < 0.001) and inversely with intraoperative etCO2 at T3(r=-0.248, P < 0.001) and T4(r=-0.251, P < 0.001).ONSD was correlated only with operation time (r=0.561, P < 0.05) and not with IOP (r=0.178, P>0.05 at T3; r=0.165, P>0.05 at T4).
CONCLUSIONS: Small tidal volume hyperventilation can relieve the increase of IOP and ONSD during prone spinal surgery under general anesthesia.