Spivack S D, Shinozaki T, Albertini J J, Deane R
Albany (NY) Medical College, USA.
Chest. 1996 May;109(5):1222-30. doi: 10.1378/chest.109.5.1222.
The hypothesis that traditionally defined preoperative risk factors predict prolonged mechanical ventilation after coronary artery bypass graft surgery (CABG) was tested in our cohort. The predictive power of these factors was quantified, and specific patient subsets destined for prolonged mechanical ventilation after CABG surgery were defined.
Five hundred thirteen consecutive patients undergoing CABG were prospectively evaluated. Preoperative pulmonary evaluation included clinical historic data, standard spirometry, and arterial blood gas. Preoperative cardiac parameters included clinical parameters and left ventricular function assessment. Nonthoracic organ (renal, endocrine, pancreas, liver) function was assessed.
University-based, tertiary referral center.
None (observational only).
Duration of mechanical ventilation, duration of surgical ICU stay, and mortality.
Multivariate regression analyses revealed that for the patient undergoing routine elective surgery and the patient undergoing urgent surgery, prolonged mechanical ventilation and death were rare events (8.3% and 2.0%, respectively). The combination of reduced left ventricular ejection fraction and the presence of selected preexisting comorbid conditions (clinical congestive heart failure, angina, current smoking, diabetes) served as modest risk factors for prolonged mechanical ventilation; their absence strongly predicted an uncomplicated postoperative respiratory course. No pulmonary diagnosis, mechanical lung function, or blood gas parameter substantially contributed to predicting adverse outcome. Classification and regression tree subgroup analysis refined specific factors important in specific subgroups.
With the exception of left ventricular ejection fraction, no preoperative factors emerge as good predictors across all subgroups. This series suggests that pulmonary diagnosis, lung mechanics, and blood gas parameters do not offer the clinician global rules in predicting postoperative respiratory outcome, nor should they be used as exclusion crteria for CABG surgery.
在我们的队列中检验传统定义的术前危险因素能否预测冠状动脉搭桥手术（CABG）后机械通气时间延长这一假设。对这些因素的预测能力进行量化，并确定CABG手术后注定要延长机械通气时间的特定患者亚组。
对513例连续接受CABG的患者进行前瞻性评估。术前肺部评估包括临床病史数据、标准肺功能测定和动脉血气分析。术前心脏参数包括临床参数和左心室功能评估。评估非胸部器官（肾脏、内分泌、胰腺、肝脏）功能。
大学附属三级转诊中心。
无（仅观察）。
机械通气时间、外科重症监护病房住院时间和死亡率。
多变量回归分析显示，对于接受常规择期手术的患者和接受急诊手术的患者，机械通气时间延长和死亡是罕见事件（分别为8.3%和2.0%）。左心室射血分数降低与某些已存在的合并症（临床充血性心力衰竭、心绞痛、当前吸烟、糖尿病）相结合是机械通气时间延长的适度危险因素；不存在这些因素强烈预示术后呼吸过程无并发症。没有肺部诊断、机械肺功能或血气参数对预测不良结局有实质性贡献。分类和回归树亚组分析细化了特定亚组中重要的特定因素。
除左心室射血分数外，没有术前因素能在所有亚组中作为良好的预测指标。本系列研究表明，肺部诊断、肺力学和血气参数不能为临床医生提供预测术后呼吸结局的通用规则，也不应将其用作CABG手术的排除标准。
