Li Jie, Gurnani Payal K, Roberts Keith M, Fink James B, Vines David
Department of Cardiopulmonary Sciences, Division of Respiratory Care, Rush University Medical Center, Chicago, IL 60612, USA.
Department of Pharmacy, Rush University Medical Center, Chicago, IL 60612, USA.
J Clin Med. 2020 Feb 7;9(2):464. doi: 10.3390/jcm9020464.
(1) Background: inhaled epoprostenol (iEPO) delivered via high-flow nasal cannula (HFNC) has been reported to be effective for pulmonary hypertension and right ventricular dysfunction. In vitro studies have identified HFNC gas flow as a key factor in trans-nasal aerosol delivery efficiency; however, little evidence is available on the clinical impact of flow titration on trans-nasal aerosol delivery. At our institution, iEPO via HFNC was initiated in 2015 and the concept of flow titration during iEPO via HFNC has been gradually accepted and carried out by clinicians in the recent years. (2) Methods: a retrospective review of the electronic medical records for all adult patients who received iEPO via HFNC in a tertiary teaching hospital. Pre- and post- iEPO responses were reported for patients whose HFNC flow was titrated or maintained constant during iEPO delivery. Positive response to iEPO was defined as the reduction of mean pulmonary arterial pressure (mPAP) > 10% for pulmonary hypertension patients or the improvement of oxygenation [pulse oximetry (SpO)/fraction of inhaled oxygen (FO)] > 20%. The number of responders to iEPO was compared between groups with titrated vs constant flow. (3) Results: 51 patients who used iEPO to treat pulmonary hypertension and/or right ventricular dysfunction were reviewed. Following iEPO administration via HFNC, mPAP decreased (43.6 ± 11.7 vs. 36.3 ± 9.7 mmHg, < 0.001). Among the 51 patients, 24 had concomitant refractory hypoxemia, their oxygenation (SpO/FO) improved after iEPO delivery (127.8 ± 45.7 vs. 157.6 ± 62.2, < 0.001). During iEPO initiation, gas flow was titrated in 25 patients and the remaining 26 patients used constant flow. The percentage of patients in the flow titration group who met the criteria for a positive response was higher compared to the group with constant flow (85.7% vs. 50%, = 0.035). Pre- vs post-iEPO responses were significant in the flow titration group included improvement in cardiac output ( = 0.050), cardiac index ( = 0.021) and FO reduction ( = 0.016). These improvements in hemodynamics and FO were not observed in the constant flow group. (4) Conclusion: in patients with pulmonary hypertension and/or right ventricular dysfunction, trans-nasal iEPO decreased pulmonary arterial pressure. It also improved oxygenation in patients with combined refractory hypoxemia. These improvements were more evident in patients whose gas flow was titrated during iEPO initiation than those patients using constant flow.
（1）背景：据报道，通过高流量鼻导管（HFNC）输送吸入性依前列醇（iEPO）对肺动脉高压和右心室功能障碍有效。体外研究已确定HFNC气流是经鼻气溶胶输送效率的关键因素；然而，关于流量滴定对经鼻气溶胶输送的临床影响的证据很少。在我们机构，2015年开始通过HFNC使用iEPO，近年来，临床医生逐渐接受并实施了在通过HFNC使用iEPO期间进行流量滴定的概念。（2）方法：对一家三级教学医院中所有通过HFNC接受iEPO的成年患者的电子病历进行回顾性分析。报告了在iEPO输送期间HFNC流量进行滴定或保持恒定的患者的iEPO前后反应。对iEPO的阳性反应定义为肺动脉高压患者的平均肺动脉压（mPAP）降低>10%，或氧合改善[脉搏血氧饱和度（SpO）/吸入氧分数（FO）]>20%。比较滴定流量组和恒定流量组对iEPO的反应者数量。（3）结果：对51例使用iEPO治疗肺动脉高压和/或右心室功能障碍的患者进行了回顾。通过HFNC给予iEPO后，mPAP降低（43.6±11.7 vs. 36.3±9.7 mmHg，P<0.001）。在51例患者中，24例伴有难治性低氧血症，iEPO输送后其氧合（SpO/FO）改善（127.8±45.7 vs. 157.6±62.2，P<0.001）。在开始使用iEPO时，25例患者进行了气流滴定，其余26例患者使用恒定流量。与恒定流量组相比，流量滴定组中符合阳性反应标准的患者百分比更高（85.7% vs. 50%，P=0.035）。在流量滴定组中，iEPO前后反应显著，包括心输出量改善（P=0.050）、心脏指数改善（P=0.021）和FO降低（P=0.016）。在恒定流量组中未观察到这些血流动力学和FO的改善。（4）结论：在肺动脉高压和/或右心室功能障碍患者中，经鼻iEPO可降低肺动脉压。它还改善了合并难治性低氧血症患者的氧合。这些改善在iEPO开始时进行气流滴定的患者中比使用恒定流量的患者更明显。
