Scales Damon C, Thiruchelvam Deva, Kiss Alexander, Redelmeier Donald A
Department of Critical Care, Sunnybrook Health Sciences Centre, University of Toronto, ON, Canada.
Crit Care Med. 2008 Sep;36(9):2547-57. doi: 10.1097/CCM.0b013e31818444a5.
Tracheostomy is common in intensive care unit patients, but the appropriate timing is controversial.
To determine whether earlier tracheostomy is associated with greater long-term survival.
Retrospective cohort analysis.
Acute care hospitals in Ontario, Canada (n = 114).
All mechanically ventilated intensive care unit patients who received tracheostomy between April 1, 1992 and March 31, 2004, excluding extreme cases (< 2 or > or = 28 days) and children (< 18 yrs).
For crude analyses, tracheostomy timing was classified as early (< or = 10 days) vs. late (> 10 days) with mortality measured at multiple follow-up intervals. Proportional hazards analyses considered tracheostomy as a time-dependent variable to adjust for measurable confounders and possible survivor treatment bias. We used stratification, propensity score, and instrumental variable analyses to adjust for patient differences.
A total of 10,927 patients received tracheostomy during the study, of which one-third (n = 3758) received early and two-thirds late (n = 7169). Patients receiving early tracheostomy had lower unadjusted 90-day (34.8% vs. 36.9%; p = 0.032), 1 yr (46.5% vs. 49.8%; p = 0.001), and study mortality (63.9% vs. 67.2%; p < 0.001) than patients receiving late tracheostomy. Multivariable analyses treating tracheostomy as a time-dependent variable showed that each additional delay of 1 day was associated with increased mortality (hazard ratio 1.008, 95% confidence interval 1.004-1.012), equivalent to an increase in 90-day mortality from 36.2% to 37.6% per week of delay (relative risk increase 3.9%; number needed to treat, 71 patients to save one life per week delay).
This analysis provides guidance regarding timing but not patient selection for tracheostomy.
Physicians performing early tracheostomy should not anticipate a large potential survival benefit. Future research should concentrate on identifying which patients will receive the most benefit.
气管切开术在重症监护病房患者中很常见，但合适的时机存在争议。
确定早期气管切开术是否与更高的长期生存率相关。
回顾性队列分析。
加拿大安大略省的急症护理医院（n = 114）。
1992年4月1日至2004年3月31日期间接受气管切开术的所有机械通气重症监护病房患者，不包括极端情况（<2天或≥28天）和儿童（<18岁）。
在粗分析中，气管切开术时机分为早期（≤10天）与晚期（>10天），在多个随访间隔测量死亡率。比例风险分析将气管切开术视为时间依赖性变量，以调整可测量的混杂因素和可能的幸存者治疗偏倚。我们使用分层、倾向评分和工具变量分析来调整患者差异。
在研究期间共有10927名患者接受了气管切开术，其中三分之一（n = 3758）接受早期手术，三分之二接受晚期手术（n = 7169）。接受早期气管切开术的患者未调整的90天（34.8%对36.9%；p = 0.032）、1年（46.5%对49.8%；p = 0.001）和研究死亡率（63.9%对67.2%；p < 0.001）低于接受晚期气管切开术的患者。将气管切开术视为时间依赖性变量的多变量分析表明，每延迟1天与死亡率增加相关（风险比1.008，95%置信区间1.004 - 1.012），相当于每延迟1周90天死亡率从36.2%增加到37.6%（相对风险增加3.9%；需要治疗的人数，每延迟1周拯救1条生命需要71名患者）。
该分析提供了关于气管切开术时机的指导，但未涉及患者选择。
进行早期气管切开术的医生不应期望有很大的潜在生存益处。未来的研究应集中于确定哪些患者将获得最大益处。
