Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.
J Clin Monit Comput. 2020 Feb;34(1):161-169. doi: 10.1007/s10877-019-00281-4. Epub 2019 Feb 20.
Elderly patients undergoing urological surgery in the lithotomy position may be vulnerable to perioperative hypoxemia. Positive end-expiratory pressure (PEEP) can improve arterial oxygenation. Although laryngeal mask airway (LMA) is widely utilized in urological surgery, it is not known how PEEP affects arterial oxygenation in these patients. We, therefore, evaluated the effect of PEEP on arterial oxygen partial pressure (PaO) in elderly patients using LMA during urological surgery in the lithotomy position. Patients randomly received zero end-expiratory pressure (group Z, n = 34) or PEEP of 7 cmHO (group P, n = 33). Ventilatory, respiratory, and haemodynamic variables were measured at 5 min (T0), 30 min (T1), and 60 min (T2) after LMA Supreme™ (sLMA) insertion. The primary outcome was the difference of PaO at T2 between the two groups. Atelectasis score, the incidence of a significant leak, and complications associated with sLMA insertion were also evaluated. PaO at T2 was significantly higher in group P than in group Z (20.0 ± 4.9 vs. 14.7 ± 3.7 kPa, P < 0.001). Atelectasis score at T2 was lower in group P than in group Z (5.3 ± 1.7 vs. 8.4 ± 2.3, P < 0.001). However, the incidence of a significant leak and complications associated with LMA insertion did not significantly differ between the two groups. PEEP can improve arterial oxygenation and reduce atelectasis in elderly patients using sLMA during urological surgery in the lithotomy position, suggesting that PEEP may be useful for elderly patients with an increased risk of perioperative hypoxemia when using sLMA.
截石位行泌尿外科手术的老年患者可能易发生围手术期低氧血症。呼气末正压通气（positive end-expiratory pressure，PEEP）可以改善动脉氧合。虽然喉罩气道（laryngeal mask airway，LMA）在泌尿外科手术中广泛应用，但尚不清楚 PEEP 对这些患者的动脉氧分压（arterial oxygen partial pressure，PaO）有何影响。因此，我们评估了在截石位行泌尿外科手术时使用 LMA 时，PEEP 对老年患者 PaO 的影响。患者随机接受零呼气末正压（group Z，n=34）或 7cmH₂O 的 PEEP（group P，n=33）。分别在 LMA Supreme 插入后 5 分钟（T0）、30 分钟（T1）和 60 分钟（T2）测量通气、呼吸和血流动力学变量。主要结局为两组 T2 时 PaO 的差值。还评估了肺不张评分、明显漏气的发生率以及与 LMA 插入相关的并发症。与 group Z 相比，group P 的 T2 时 PaO 显著升高（20.0±4.9 比 14.7±3.7kPa，P<0.001）。与 group Z 相比，group P 的 T2 时肺不张评分较低（5.3±1.7 比 8.4±2.3，P<0.001）。然而，两组间明显漏气的发生率以及与 LMA 插入相关的并发症无显著差异。PEEP 可改善截石位行泌尿外科手术时使用 LMA 的老年患者的动脉氧合，减少肺不张，提示在使用 LMA 时，PEEP 可能对有围手术期低氧血症风险增加的老年患者有益。
