Institut Clinic del Torax, Hospital Clinic, IDIBAPS, Universitat de Barcelona, Barcelona, Spain.
Intensive Care Med. 2011 May;37(5):775-84. doi: 10.1007/s00134-011-2179-3. Epub 2011 Mar 4.
An International Consensus Conference proposed classifying weaning into simple, difficult, and prolonged weaning. However, the usefulness of this classification in a respiratory intensive care unit (ICU) is unknown. The aims of the study were: (1) to compare the clinical characteristics and outcomes of patients from the three weaning groups in a respiratory ICU; and (2) to assess predictors for prolonged weaning and survival.
We prospectively studied 181 mechanically ventilated patients (131, 72% with chronic respiratory disorders) in whom weaning had been initiated, divided into simple (78, 43%), difficult (70, 39%), and prolonged (33, 18%) weaning. We compared the characteristics and outcomes among the three groups and determined the factors associated with prolonged weaning and survival in multivariate analysis.
Patients with simple and difficult weaning had similar characteristics and outcomes. A higher proportion of patients with prolonged weaning had chronic obstructive pulmonary disease, and these patients also had more complications, a longer stay and lower survival. Increased heart rate (≥105 min(-1), p < 0.001) and PaCO(2) (≥ 54 mmHg, p = 0.001) during the spontaneous breathing trial independently predicted prolonged weaning. In addition, the need for reintubation (p < 0.001) and hypercapnia during the spontaneous breathing trial (p = 0.003) independently predicted a decreased 90-day survival.
Because of the similar characteristics and outcomes, the differentiation between simple and difficult weaning had no relevant clinical consequences in a respiratory ICU. Patients with prolonged weaning had the worst outcomes. For the overall population, hypercapnia at the end of spontaneous breathing predicts prolonged weaning and a worse survival, and clinicians should implement measures aimed at improving weaning outcome.
国际共识会议提出将撤机分为简单、困难和延长撤机。然而，这种分类在呼吸重症监护病房（ICU）中的实用性尚不清楚。本研究的目的是：（1）比较呼吸 ICU 中三组撤机患者的临床特征和结局；（2）评估延长撤机和生存的预测因素。
我们前瞻性研究了 181 例接受机械通气的患者（131 例，72%患有慢性呼吸系统疾病），这些患者已经开始撤机，分为简单（78 例，43%）、困难（70 例，39%）和延长（33 例，18%）撤机。我们比较了三组患者的特征和结局，并在多变量分析中确定了与延长撤机和生存相关的因素。
简单和困难撤机患者具有相似的特征和结局。延长撤机患者中慢性阻塞性肺疾病的比例较高，这些患者并发症更多，住院时间更长，生存率更低。在自主呼吸试验中，心率（≥105 次/分，p<0.001）和 PaCO2（≥54mmHg，p=0.001）升高独立预测延长撤机。此外，需要再次插管（p<0.001）和自主呼吸试验期间的高碳酸血症（p=0.003）独立预测 90 天生存率降低。
由于简单和困难撤机具有相似的特征和结局，因此在呼吸 ICU 中，两者之间的区别没有明显的临床意义。延长撤机患者的结局最差。对于总体人群，自主呼吸试验结束时的高碳酸血症预测延长撤机和更差的生存，临床医生应采取措施改善撤机结局。
