Isocapnic hyperventilation (ICHV) is occasionally used to maintain the end-expired CO₂ partial pressure (P_ETCO₂) when the inspired CO₂ (P_ICO₂) rises. Whether maintaining P_ETCO₂ with ICHV during an increase of the P_ICO₂ also maintains arterial PCO₂ (P_aCO₂) remains poorly documented. 12 ASA PS I–II subjects undergoing a robot-assisted radical prostatectomy (RARP) (n = 11) or cystectomy (n = 1) under general endotracheal anesthesia with sevoflurane in O₂/air (40% inspired O₂) were enrolled. P_ICO₂ was sequentially increased from 0 to 0.5, 1.0, 1.5 and 2% by adding CO₂ to the inspiratory limb of the circle system, while increasing ventilation to a target P_ETCO₂ of 4.7–4.9% by adjusting respiratory rate during controlled mechanical ventilation. P_a-ETCO₂ gradients were determined after a 15 min equilibration period at each P_ICO₂ level and compared using ANOVA. Mean (standard deviation) age, height, and weight were 66 (6) years, 171 (6) cm, and 75 (8) kg, respectively. Capnograms were normal and hemodynamic parameters remained stable. P_ETCO₂ could be maintained within 4.7–4.9% in all subjects at all times except in 1 subject with 1.5% P_ICO₂ and 5 subjects with 2.0% P_ICO₂; data from the one subject in whom both 1.5 and 2.0% P_ICO₂ resulted in P_ETCO₂ > 5.1% were excluded from analysis. P_a-ETCO₂ gradients did not change when P_ICO₂ increased. The effect of a modest rise of P_ICO₂ up to 1.5% on P_ETCO₂ during RARP can be readily overcome by increasing ventilation without altering the P_a-ETCO₂ gradients. At higher P_ICO₂, airway pressures may become a limiting factor, which requires further study.

当吸入的 CO 2 (P _I CO ₂ ) 升高时，偶尔会使用等碳酸过度通气 (ICHV) 来维持呼气末 CO _2分压 ( P _ET CO ₂ )。_{在 P I} CO ₂增加期间维持 P _ET CO ₂与 ICHV 是否也维持动脉 PCO ₂ (P _a CO ₂ ) 仍然缺乏记录。12 名接受机器人辅助根治性前列腺切除术 (RARP) (n = 11) 或膀胱切除术 (n = 1) 的 ASA PS I–II 受试者在气管内全身麻醉下使用 O 2 /空气中的七氟醚（40%_吸入O₂）被录取。_{通过将 CO 2}添加到循环系统的吸气肢，将P _I CO ₂从 0 依次增加到 0.5、1.0、1.5 和 2% ，同时通过调整呼吸频率将通气量增加到 4.7–4.9% 的目标 P _ET CO ₂在控制机械通气期间。_{在每个 P I} CO ₂水平的15 分钟平衡期后确定P _a-ET CO _{2梯度，并使用方差分析进行比较。}平均（标准差）年龄、身高和体重分别为 66 (6) 岁、171 (6) cm 和 75 (8) kg。二氧化碳图正常，血流动力学参数保持稳定。聚_乙二醇__{除了 1 名 P I} CO ₂为 1.5% 的受试者和 5 名 P _I CO _{2为 2.0% 的受试者外，所有受试者的2}可始终保持在 4.7–4.9% 以内；_{来自 1.5% 和 2.0% P I} CO ₂导致 P _ET CO ₂  > 5.1% 的受试者的数据被排除在分析之外。_{当 P I} CO ₂增加时， P _a-ET CO ₂梯度没有改变。_{P I} CO ₂适度上升至 1.5% 对 P _ET CO ₂的影响在不改变 P _a-ET CO ₂梯度的情况下，可以通过增加通风轻松克服 RARP 期间的问题。在较高的 P _I CO ₂下，气道压力可能成为一个限制因素，这需要进一步研究。