驱动压导向呼气末正压通气对原位肝移植患者术中氧合和术后并发症的影响

目的： 评价驱动压导向呼气末正压（PEEP）通气对原位肝移植术（OLT）患者术中氧合和术后并发症的影响。
方法： 选择2020年1月至2023年9月行OLT患者118例，男89例，女29例，年龄18～70岁，BMI＜28 kg/m² ，ASA Ⅲ或Ⅳ级。采用随机数字表法将患者分为两组：驱动压组（D组）和固定PEEP组（P组），每组59例。两组全麻期间均采用容量控制通气，I∶E 1∶2，V_T 6 ml/kg（理想体重），RR 10～15次/分。D组在机械通气5 min后开始PEEP滴定试验，将PEEP从2 cmH₂O逐渐递增到10 cmH₂O，选择能产生最低驱动压的PEEP，维持该PEEP直至手术结束。P组术中维持PEEP 5 cmH₂O。记录术中出入量、血管活性药物使用情况。记录插管后5 min（T₁）、无肝期（T₂）、新肝期（T₃）、手术结束即刻（T₄）的HR、SBP、DBP、气道峰压（Ppeak）、气道平台压（Pplat）、PEEP、血气分析结果，并计算驱动压、动态肺顺应性（Cdyn）、氧合指数（OI）、死腔率（V_D/ V_T）。记录术后7 d内术后肺部并发症（PPCs）的发生情况。
结果： 与P组比较，D组晶体液输注量明显增加，去甲肾上腺素、去氧肾上腺素及肾上腺素使用率明显升高（P<0.05）。与T₂时比较，两组T₁、T₃、T₄时HR明显减慢，SBP、DBP明显升高（P<0.05）。与T₁时比较，两组T₂—T₄时Ppeak、Pplat、驱动压、OI明显升高，T₃、T₄时Cdyn明显降低（P<0.05）。与P组比较，D组术后7 d内PPCs发生率明显降低（P<0.05）。两组其余指标差异无统计学意义。
结论： 驱动压导向PEEP通气可改善原位肝移植患者术中氧合，降低PPCs发生率，但术中血管活性药物的使用率升高。

Effects of positive end-expiratory pressure guided by driving pressure on intraoperative oxygenation and postoperative complications in patients undergoing orthotopic liver transplantation

Objective: To evaluate the application effect of positive end-expiratory pressure (PEEP) guided by driving pressure on intraoperative oxygenation and postoperative complications in patients undergoing orthotopic liver transplantation (OLT).
Methods: A total of 118 patients underwent OLT from January 2020 to September 2023, 89 males and 29 females, aged 18-70 years, BMI < 28 kg/m², ASA physical status Ⅲ or Ⅳ. Patients were divided into two groups using the random number table method: drive pressure group (group D) and PEEP group (group P), 59 patients in each group. Volume controlled ventilation was used during general anesthesia in two groups, I∶E 1∶2, V_T 6 ml/kg (ideal body weight), RR 10-15 beats/minute. In group D, the PEEP titration test was started after 5 minutes of mechanical ventilation, gradually increasing PEEP from 2 to 10 cmH₂O, selecting the PEEP that produced the lowest driving pressure, and maintaining this PEEP until the end of the surgery. In group P, the PEEP was maintained at 5 cmH₂O during surgery. The amount of intraoperative out put and intake, and the use of vasoactive drugs were recorded. The HR, SBP, DBP, peak airway pressure (Ppeak), airway plateau pressure (Pplat), PEEP, and blood gas analysis results were recorded 5 minutes after intubation (T₁), during the anhepatic phase (T₂), during the neohepatic phase (T₃), and at the end of the operation (T₄), and driving pressure, dynamic pulmonary compliance (Cdyn), oxygenation index (OI), and dead space fraction (V_D/V_T) were calculated. The occurrence of postoperative pulmonary complications (PPCs) within 7 days after operation was recorded.
Results: Compared with group P, the amount of crystalloid and the usage frequencies of norepinephrine, phenylephrine, and epinephrine in group D were significantly increased (P < 0.05). Compared with T₂, HR was significantly decreased, SBP and DBP were significantly increased at T₁, T₃, and T₄ in the two groups (P < 0.05). Compared with T₁, Ppeak, Pplat, driving pressure, and OI were significantly increased at T₂-T₄, and Cdyn was significantly decreased at T₃ and T₄ in the two groups (P < 0.05). Compared with group P, the incidence of PPCs in group D was significantly decreased (P < 0.05). There were no significant differences in other indexes between the two groups.
Conclusion: The driving pressure guided PEEP ventilation improves intraoperative oxygenation and reduces the incidence of PPCs in patients undergoing OLT, but the use of intraoperative vasoactive drugs increases.