Department of Anesthesiology and General Intensive Care Unit, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582 Japan.
Department of Anesthesia, Kawasaki Municipal Hospital, 12-1 Shinkawadori, Kawasaki-ku, Kawasaki-shi, Kanagawa 210-0013 Japan.
J Intensive Care. 2014 Jan 23;2(1):5. doi: 10.1186/2052-0492-2-5. eCollection 2014.
It remains to be clarified if the application of noninvasive positive pressure ventilation (NPPV) is effective after extubation in patients with hypoxemic respiratory failure who require the sufficient level of positive end-expiratory pressure (PEEP). This study was aimed at examining the effect and the safety of NPPV application following extubation in patients requiring moderate PEEP level for sufficient oxygenation after cardiovascular surgery.
With institutional ethic committee approval, the patients ventilated invasively for over 48 h after cardiovascular surgery were enrolled in this study. The patients who failed the first spontaneous breathing trial (SBT) at 5 cmH2O of PEEP, but passed the second SBT at 8 cmH2O of PEEP, received NPPV immediately after extubation following our weaning protocol. Respiratory parameters (partial pressure of arterial oxygen tension to inspiratory oxygen fraction ratio: P/F ratio, respiratory ratio, and partial pressure of arterial carbon dioxide: PaCO2) 2 h after extubation were evaluated with those just before extubation as the primary outcome. The rate of re-intubation, the frequency of respiratory failure and intolerance of NPPV, the duration of NPPV, and the length of intensive care unit (ICU) stay were also recorded.
While 51 postcardiovascular surgery patients were screened, 6 patients who met the criteria received NPPV after extubation. P/F ratio was increased significantly after extubation compared with that before extubation (325 ± 85 versus 245 ± 55 mmHg, p < 0.05). The other respiratory parameters did not change significantly. Re-intubation, respiratory failure, and intolerance of NPPV never occurred. The duration of NPPV and the length of ICU stay were 2.7 ± 0.7 (SD) and 7.5 (6 to 10) (interquartile range) days, respectively.
While further investigation should be warranted, NPPV could be applied effectively and safely after extubation in patients requiring the moderate PEEP level after cardiovascular surgery.
对于需要足够水平的呼气末正压通气（PEEP）的低氧性呼吸衰竭患者，在拔管后应用无创正压通气（NPPV）是否有效仍需阐明。本研究旨在检查在心血管手术后需要中等 PEEP 水平以充分氧合的患者中，拔管后应用 NPPV 的效果和安全性。
本研究获得机构伦理委员会批准，纳入了在心血管手术后接受了超过 48 小时有创通气的患者。这些患者在 5cmH2O 的 PEEP 下首次自主呼吸试验（SBT）失败，但在 8cmH2O 的 PEEP 下通过了第二次 SBT，根据我们的脱机方案，在拔管后立即接受 NPPV。以拔管前的呼吸参数（动脉血氧分压与吸入氧分数的比值：P/F 比值、呼吸比和动脉二氧化碳分压：PaCO2）作为主要观察指标，评估拔管后 2 小时的呼吸参数。记录再插管率、NPPV 不耐受和呼吸衰竭的频率、NPPV 的持续时间和重症监护病房（ICU）的住院时间。
虽然对 51 例心血管手术后患者进行了筛选，但符合标准的 6 例患者在拔管后接受了 NPPV。与拔管前相比，拔管后 P/F 比值显著升高（325±85 对 245±55mmHg，p<0.05）。其他呼吸参数无明显变化。未发生再插管、呼吸衰竭和 NPPV 不耐受。NPPV 的持续时间和 ICU 住院时间分别为 2.7±0.7（标准差）和 7.5（6 至 10）天（四分位距）。
虽然需要进一步研究，但在心血管手术后需要中等 PEEP 水平的患者中，拔管后可有效且安全地应用 NPPV。
