Ely E W, Evans G W, Haponik E F
Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, Tennessee 37232-4760, USA.
Ann Intern Med. 1999 Jul 20;131(2):96-104. doi: 10.7326/0003-4819-131-2-199907200-00004.
It has been argued that life support for the elderly should be limited to conserve resources. As this population increases, so will the importance of evaluating appropriate use of mechanical ventilation in this group.
To determine whether age has an independent effect on the outcomes of patients treated with mechanical ventilation after admission to an intensive care unit (ICU).
Prospective cohort study.
University-based tertiary care medical center.
63 patients 75 years of age or older and 237 patients younger than 75 years of age enrolled from medical and coronary ICUs.
In-hospital mortality rate, duration of mechanical ventilation, lengths of stay in the ICU and in the hospital, and cost of care.
Median duration of mechanical ventilation was 4.2 days (interquartile range, 2.1 to 9.3 days) for patients 75 years of age or older and 6.4 days (interquartile range, 3.4 to 11.4 days) for patients younger than 75 years of age (P = 0.14). When the length of time required to "pass" a daily screening test of weaning variables was used as an indicator of recovery from respiratory failure, elderly patients passed earlier than younger patients (risk ratio, 1.58 [95% CI, 1.13 to 2.22]; P = 0.03). The cost of ICU care was lower for older ($12,822 [CI, $9821 to $26,313] than for younger ($19,316 [CI, $9699 to $39,950]) patients (P = 0.03). Median hospital costs tended to be lower in the older group ($21,292 compared with $29,049; P = 0.17). After adjustment for ethnicity, sex, and severity of illness in a multivariate logistic regression analysis, patient age of 75 years or older was predictive of 1 less day on the ventilator (CI, -2.8 to 1.2 days). Lengths of stay in the ICU (beta-coefficient, -0.5 days [CI, -3.0 to 2.7 days]) and in the hospital (beta-coefficient, 0.3 days [CI, -3.7 to 5.5 days]) did not differ for persons 75 years of age or older after these adjustments (P > 0.1). Intensive care unit and hospital costs, however, were lower for elderly persons (P = 0.02). The in-hospital mortality rate was 38.1% among elderly patients and 38.8% among younger patients (P > 0.2); Cox proportional hazards analysis confirmed that survival did not differ between the two groups (relative risk for older patients, 0.82 [CI, 0.52 to 1.29]).
After adjustment for severity of illness, elderly patients spent similar time on mechanical ventilation and in the ICU and hospital but had a lower cost of care than younger patients. These outcomes are not explained by differences in mortality rate and suggest that mechanical ventilation should not be restricted in elderly patients with respiratory failure on the basis of chronologic age.
有人认为应限制对老年人的生命支持以节约资源。随着这一人群的增加，评估该群体机械通气的合理使用的重要性也会增加。
确定年龄对入住重症监护病房（ICU）后接受机械通气治疗的患者的预后是否有独立影响。
前瞻性队列研究。
大学附属三级医疗中心。
从内科和冠心病ICU招募的63名75岁及以上患者和237名75岁以下患者。
住院死亡率、机械通气时间、在ICU和医院的住院时间以及护理费用。
75岁及以上患者机械通气的中位时间为4.2天（四分位间距，2.1至9.3天），75岁以下患者为6.4天（四分位间距，3.4至11.4天）（P = 0.14）。当将通过每日撤机变量筛查测试所需的时间作为呼吸衰竭恢复的指标时，老年患者比年轻患者更早通过（风险比，1.58 [95% CI，1.13至2.22]；P = 0.03）。老年患者（12,822美元[CI，9821美元至26,313美元]）的ICU护理费用低于年轻患者（19,316美元[CI，9699美元至39,950美元]）（P = 0.03）。老年组的中位住院费用往往较低（21,292美元，而年轻组为29,049美元；P = 0.17）。在多因素逻辑回归分析中对种族、性别和疾病严重程度进行调整后，75岁及以上患者的年龄可预测机械通气时间减少1天（CI，-2.8至1.2天）。调整后，75岁及以上患者在ICU（β系数，-0.5天[CI，-3.0至2.7天]）和医院（β系数，0.3天[CI，-3.7至5.5天]）的住院时间无差异（P > 0.1）。然而，老年患者的ICU和医院费用较低（P = 0.02）。老年患者的住院死亡率为38.1%，年轻患者为38.8%（P > 0.2）；Cox比例风险分析证实两组的生存率无差异（老年患者的相对风险，0.82 [CI，0.52至1.29]）。
在对疾病严重程度进行调整后，老年患者接受机械通气以及在ICU和医院的时间与年轻患者相似，但护理费用较低。这些结果不能用死亡率的差异来解释，这表明不应基于年龄限制对呼吸衰竭老年患者进行机械通气。
