Comment & Response November 5, 2019<\/p>\n\n\n\n
To the Editor<\/strong>\u00a0<\/p>\n\n\n\n The results of the randomized clinical trial reported by Dr Subir\u00e0 and colleagues compared a less demanding spontaneous breathing trial (SBT) of 30 minutes of pressure support ventilation (PSV) with a more demanding 2-hour T-piece SBT and showed a higher successful extubation rate favoring the less demanding test without a higher need for reintubation.1<\/a><\/sup>\u00a0In this trial, clinicians, who were not blinded to treatment assignment, made greater use of prophylactic respiratory interventions in the PSV group (24.7%) (8.9% noninvasive ventilation [NIV] + 15.8% high-flow nasal cannula [HFNC]) compared with the T-piece group (18.7%) (5.9% NIV + 12.8% HFNC). This analysis is limited to prophylactic use and not total use of NIV and HFNC after extubation. Moreover, it assumes that individual patients were treated prophylactically with either NIV or HFNC but not both.<\/p>\n\n\n\n Subir\u00e0\u533b\u751f\u53ca\u5176\u540c\u4e8b\u62a5\u544a\u7684\u968f\u673a\u4e34\u5e8a\u8bd5\u9a8c\u6bd4\u8f83\u4e86\u9700\u6c42\u8f83\u5c11\u7684\u81ea\u4e3b\u547c\u5438\u8bd5\u9a8c(SBT)\u537330\u5206\u949f\u538b\u529b\u652f\u6301\u901a\u6c14(PSV)\u4e0e\u9700\u8981\u66f4\u9ad8\u76842\u5c0f\u65f6T\u7ba1SBT\uff0c\u7ed3\u679c\u663e\u793a\uff0c\u9700\u6c42\u8f83\u5c11\u7684\u8bd5\u9a8c\u62d4\u7ba1\u6210\u529f\u7387\u8f83\u9ad8\uff0c\u518d\u63d2\u7ba1\u7387\u5e76\u4e0d\u589e\u52a0\u3002\u8fd9\u9879\u4e34\u5e8a\u8bd5\u9a8c\u7684\u8bd5\u9a8c\u5206\u7ec4\u672a\u5bf9\u4e34\u5e8a\u533b\u751f\u8bbe\u76f2\uff0c\u56e0\u6b64\u4e34\u5e8a\u533b\u751f\u5728PSV\u7ec4\u66f4\u591a\u91c7\u7528\u4e86\u9884\u9632\u6027\u547c\u5438\u5e72\u9884(24.7%) (8.9% \u65e0\u521b\u901a\u6c14 [NIV] + 15.8% \u9ad8\u6d41\u91cf\u9f3b\u5bfc\u7ba1 [HFNC]) \u800cT\u7ba1\u7ec4\u4ec5\u4e3a (18.7%) (5.9% NIV + 12.8% HFNC)\u3002\u8fd9\u4e00\u5206\u6790\u4ec5\u9650\u4e8e\u9884\u9632\u6027\u4f7f\u7528\u800c\u672a\u5305\u62ec\u62d4\u7ba1\u540e\u6240\u6709\u7684NIV\u548cHFNC\u7684\u4f7f\u7528\u3002\u7136\u800c\uff0c\u8fd9\u4e00\u5206\u6790\u5047\u8bbe\u60a3\u8005\u5206\u522b\u9884\u9632\u6027\u4f7f\u7528NIV\u6216HFNC\u800c\u975e\u4e24\u8005\u90fd\u662f\u7528<\/p>\n\n\n\n It is important to distinguish between prophylactic use of respiratory support interventions and total use of NIV and HFNC that also includes use of NIV and HFNC for postextubation respiratory failure. The authors reported postextubation use of respiratory support interventions for respiratory failure in aggregate across both treatment groups but not separately by treatment group. Consequently, whether increased use of NIV and HFNC may have been required after extubation to avoid reintubation in the PSV group is not clear. These results are important as clinicians may need to be prepared to make greater use of prophylactic respiratory interventions after extubation when using a less demanding PSV rather than a more demanding T-piece SBT technique. To provide more guidance for clinicians, it would be helpful to know the total number of patients in the PSV vs T-piece groups who actually used NIV or HFNC after extubation, either prophylactically or for postextubation respiratory failure.<\/p>\n\n\n\n \u533a\u5206\u9884\u9632\u6027\u4f7f\u7528\u547c\u5438\u652f\u6301\u6cbb\u7597\u4e0eNIV\/HFNC\u7684\u5168\u90e8\u4f7f\u7528\u975e\u5e38\u91cd\u8981\uff0c\u56e0\u4e3a\u540e\u8005\u8fd8\u5305\u62ec\u4f7f\u7528NIV\/HFNC\u6cbb\u7597\u62d4\u7ba1\u540e\u547c\u5438\u8870\u7aed\u3002\u4f5c\u8005\u62a5\u544a\u4e86\u4e24\u4e2a\u6cbb\u7597\u7ec4\u6574\u4f53\u7528\u4e8e\u6cbb\u7597\u62d4\u7ba1\u540e\u547c\u5438\u529f\u80fd\u8870\u7aed\u4f7f\u7528\u547c\u5438\u652f\u6301\u63aa\u65bd\u7684\u60c5\u51b5\uff0c\u4f46\u672a\u5206\u7ec4\u62a5\u544a\u6570\u636e\u3002\u56e0\u6b64\uff0cPSV\u7ec4NIV\/HFNC\u7684\u4f7f\u7528\u589e\u52a0\u662f\u5426\u6e90\u4e8e\u62d4\u7ba1\u540e\u907f\u514d\u518d\u6b21\u63d2\u7ba1\u5e76\u4e0d\u6e05\u695a\u3002\u8fd9\u4e9b\u7ed3\u679c\u975e\u5e38\u91cd\u8981\uff0c\u56e0\u4e3a\u5728\u91c7\u7528\u9700\u8981\u8f83\u5c11\u7684PSV\u800c\u975e\u9700\u8981\u66f4\u591a\u7684T\u7ba1SBT\u540e\uff0c\u4e00\u65e6\u80fd\u591f\u62d4\u7ba1\uff0c\u4e34\u5e8a\u533b\u751f\u53ef\u80fd\u9700\u8981\u51c6\u5907\u66f4\u591a\u4f7f\u7528\u9884\u9632\u6027\u547c\u5438\u6cbb\u7597\u63aa\u65bd\u3002\u4e86\u89e3PSV\u7ec4\u4e0eT\u7ba1\u7ec4\u60a3\u8005\u62d4\u7ba1\u540eNIV\u6216HFNC\u7684\u5b9e\u9645\u4f7f\u7528\u60c5\u51b5\uff0c\u5bf9\u4e34\u5e8a\u533b\u751f\u6709\u66f4\u591a\u7684\u6307\u5bfc\u610f\u4e49\u3002<\/p>\n\n\n\n Comment & Response November 5, 2019<\/p>\n\n\n\n To the Editor<\/strong>\u00a0<\/p>\n\n\n\n Dr Subir\u00e0 and colleagues evaluated 2 types of SBTs to evaluate readiness for extubation, a short-duration (30-minute) PSV strategy compared with a long-duration (2-hour) T-piece strategy, and found higher extubation rates with the PSV strategy (82.3% vs 74.0% at 72 hours; 92.5% vs 84.1% after the first SBT), with no difference in reintubation rates within 72 hours of extubation (11.1% vs 11.9%).1<\/a><\/sup>\u00a0Surprisingly, patients underwent their first SBT when the pretest probability of successful separation from the ventilator was already extremely high (as indicated by the success rate of the trial). When the pretest probability is high, any test or strategy having a risk of false-negative results (ie, predicting failure in a patient who could be extubated) will compromise predictive performance, whereas the risk of false-positive results (ie, predicting success in a patient who cannot be extubated) will be almost nonexistent.2<\/a><\/sup>\u00a0The design of this study put the T-piece group at higher risk of false-negative results than the PSV group.3<\/a>,4<\/a><\/sup>\u00a0The results were therefore expected, as predicted by Bayes\u2019 theorem.2<\/a><\/sup>\u00a0The relevant question for clinical practice is why the authors included patients at a late stage when the pretest probability of extubation was already high. Moreover, the absence of differences in length of stay in the intensive care unit casts doubt on any inference that the 30-minute PSV strategy meaningfully accelerated liberation from mechanical ventilation.<\/p>\n\n\n\n Subir\u00e0\u533b\u751f\u53ca\u5176\u540c\u4e8b\u8bc4\u4ef7\u4e86\u4e24\u79cdSBT\u65b9\u5f0f\u5bf9\u62d4\u7ba1\u53ef\u884c\u6027\u7684\u5224\u65ad\uff0c\u5176\u4e2d\u4e00\u79cd\u4e3a\u77ed\u65f6\u95f4(30\u5206\u949f) PSV\u7b56\u7565\uff0c\u53e6\u4e00\u79cd\u4e3a\u8f83\u957f\u65f6\u95f4 (2\u5c0f\u65f6) T\u7ba1\u7b56\u7565\u3002\u7ed3\u679c\u53d1\u73b0\uff0cPSV\u7b56\u7565\u62d4\u7ba1\u7387\u8f83\u9ad8 (72\u5c0f\u65f6 82.3% vs 74.0%; \u9996\u6b21SBT\u540e 92.5% vs 84.1%)\uff0c\u800c\u62d4\u7ba1\u540e72\u5c0f\u65f6\u5185\u518d\u6b21\u63d2\u7ba1\u7387\u65e0\u5dee\u5f02 (11.1% vs 11.9%)\u3002\u5947\u602a\u7684\u662f\uff0c\u60a3\u8005\u8fdb\u884c\u9996\u6b21SBT\u65f6\u5176\u6210\u529f\u8131\u79bb\u547c\u5438\u673a\u7684\u9a8c\u524d\u6982\u7387\u5373\u5df2\u5f88\u9ad8 (\u5982\u62d4\u7ba1\u6210\u529f\u7387\u63d0\u793a)\u3002\u5f53\u9a8c\u524d\u6982\u7387\u5f88\u9ad8\u65f6\uff0c\u4efb\u4f55\u5177\u6709\u5047\u9634\u6027\u7ed3\u679c\u98ce\u9669 (\u5373\u5bf9\u4e8e\u6210\u529f\u62d4\u7ba1\u60a3\u8005\u9884\u6d4b\u62d4\u7ba1\u5931\u8d25) \u7684\u68c0\u9a8c\u6216\u7b56\u7565\u90fd\u53ef\u80fd\u5f71\u54cd\u9884\u6d4b\u51c6\u786e\u6027\uff0c\u800c\u5047\u9633\u6027\u7ed3\u679c\u98ce\u9669 (\u5373\u5bf9\u4e8e\u4e0d\u80fd\u62d4\u7ba1\u60a3\u8005\u9884\u6d4b\u62d4\u7ba1\u6210\u529f) \u51e0\u4e4e\u4e0d\u5b58\u5728\u3002\u8fd9\u9879\u7814\u7a76\u7684\u5b9e\u9a8c\u8bbe\u8ba1\u5c06T\u7ba1\u7ec4\u8f83PSV\u7ec4\u7f6e\u4e8e\u66f4\u9ad8\u7684\u5047\u9634\u6027\u98ce\u9669\u3002\u56e0\u6b64\uff0c\u8fd9\u4e00\u7ed3\u679c\u6b63\u5982Bayes\u5b9a\u7406\u6240\u9884\u671f\u3002\u4e0e\u4e34\u5e8a\u5b9e\u8df5\u76f8\u5173\u7684\u95ee\u9898\u662f\uff0c\u4f5c\u8005\u4e3a\u4f55\u5728\u665a\u671f\u7eb3\u5165\u60a3\u8005\uff0c\u6b64\u65f6\u9a8c\u524d\u6982\u7387\u5df2\u975e\u5e38\u9ad8\u3002\u800c\u4e14\uff0cICU\u4f4f\u9662\u65e5\u6ca1\u6709\u5dee\u5f02\u7684\u4e8b\u5b9e\uff0c\u4f7f\u5f97\u4eba\u4eec\u5bf9\u4e8e30\u5206\u949fPSV\u7b56\u7565\u52a0\u5feb\u8131\u673a\u8fdb\u7a0b\u7684\u63a8\u65ad\u4ea7\u751f\u4e86\u8d28\u7591\u3002<\/p>\n\n\n\n The authors also mentioned that \u201c\u2026a prespecified interim analysis was performed\u2026showed a nonsignificant difference in primary outcome between groups and\u2026the investigators decided to complete the estimated sample enrollment.\u201d Because the study was not blinded and the use of prophylactic NIV or HFNC after extubation was left to the discretion of attending physicians, it would be important to know how the primary outcome (successful extubation) and baseline characteristics and interventions differed between the first interim 500 patients (in whom no differences were found in the primary outcome) and the second cohort that led to the significant difference in the primary outcome.<\/p>\n\n\n\n \u4f5c\u8005\u8fd8\u63d0\u5230\uff0c\u201c...\u8fdb\u884c\u4e86\u9884\u5148\u786e\u5b9a\u7684\u4e2d\u671f\u5206\u6790...\u7ed3\u679c\u663e\u793a\uff0c\u4e24\u7ec4\u95f4\u4e3b\u8981\u9884\u540e\u6307\u6807\u6ca1\u6709\u663e\u8457\u5dee\u5f02...\u7814\u7a76\u8005\u51b3\u5b9a\u5b8c\u6210\u9884\u8ba1\u7684\u6837\u672c\u91cf\u3002\u201d\u56e0\u4e3a\u7814\u7a76\u5e76\u672a\u8bbe\u76f2\uff0c\u62d4\u7ba1\u540e\u9884\u9632\u6027\u4f7f\u7528NIV\u6216HFNC\u7531\u4e3b\u6cbb\u533b\u751f\u51b3\u5b9a\uff0c\u56e0\u6b64\uff0c\u4e86\u89e3\u7b2c\u4e00\u6b21\u4e2d\u671f\u5206\u6790\u65f6500\u540d\u60a3\u8005\u7684\u4e3b\u8981\u9884\u540e\u6307\u6807\uff08\u6210\u529f\u62d4\u7ba1\uff09\u4e0e\u57fa\u7ebf\u7279\u5f81\u548c\u5e72\u9884\u63aa\u65bd\u4e4b\u95f4\u7684\u5dee\u5f02\uff08\u4e3b\u8981\u9884\u540e\u6307\u6807\u6ca1\u6709\u5dee\u5f02\uff09\uff0c\u4ee5\u53ca\u540e\u7eed\u961f\u5217\uff08\u4e3b\u8981\u6307\u6807\u5dee\u5f02\u663e\u8457\uff09\u76f8\u5e94\u6307\u6807\u7684\u5dee\u5f02\u975e\u5e38\u91cd\u8981\u3002<\/p>\n","protected":false},"excerpt":{"rendered":" Comment & Response November 5, 2019 […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[24,23],"tags":[],"_links":{"self":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/17910"}],"collection":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=17910"}],"version-history":[{"count":3,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/17910\/revisions"}],"predecessor-version":[{"id":17996,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=\/wp\/v2\/posts\/17910\/revisions\/17996"}],"wp:attachment":[{"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=17910"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17910"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/csccm.org.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17910"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Spontaneous Breathing Trials and Successful Extubation<\/h1>\n\n\n\n
Jordi Mancebo, Ewan Goligher, Laurent Brochard<\/h3>\n\n\n\n
JAMA. <\/em>2019;322(17):1716-1717. doi:10.1001\/jama.2019.14226<\/h3>\n\n\n\n