加拿大谢布克大学François Lamontagne研究团队最近研究了减少加压素暴露对老年血管扩张性低血压危重患者90天死亡率的影响。相关论文2020年2月12日在线发表于国际顶尖学术期刊《美国医学会杂志》。

重症监护室（ICU）患者通常使用加压素来升高血压。平衡加压素的风险和益处是一项挑战，尤其对老年患者而言。

为了探讨允许性低血压是否能降低65岁及以上ICU患者90天内的死亡率，2017年7月至2019年3月，研究组在英国的65个ICU中进行了一项多中心、实用性、随机、临床试验。

研究组招募了2600名65岁及以上伴有血管扩张性低血压的患者，将其按1：1随机分组，其中1291名接受允许性低血压治疗，即平均动脉压目标为60-65mmHg；1307名接受常规治疗。

最终有2463名患者被纳入主要结果分析。允许性低血压组的患者使用加压素的中位持续时间为33小时，显著短于常规治疗组（38小时）。允许性低血压组患者的90天死亡率为41.0%，而常规治疗组为43.8%，校正后的比值比为0.82。

允许性低血压组有79名患者（6.2%）发生严重不良事件，包括41例急性肾功能衰竭和12例室上性心律失常；常规治疗组有75名（5.8%），包括33例急性肾功能衰竭和12例室上性心律失常。

总之，对于65岁及以上接受加压药来治疗血管扩张性低血压的老年患者，允许性低血压与常规治疗相比，并不能显著降低90天内的死亡率。

附：英文原文

Title: Effect of Reduced Exposure to Vasopressors on 90-Day Mortality in Older Critically Ill Patients With Vasodilatory Hypotension: A Randomized Clinical Trial

Author: Franois Lamontagne, Alvin Richards-Belle, Karen Thomas, David A. Harrison, M. Zia Sadique, Richard D. Grieve, Julie Camsooksai, Robert Darnell, Anthony C. Gordon, Doreen Henry, Nicholas Hudson, Alexina J. Mason, Michelle Saull, Chris Whitman, J. Duncan Young, Kathryn M. Rowan, Paul R. Mouncey

Issue&Volume: February 12, 2020

Abstract:

Importance  Vasopressors are commonly administered to intensive care unit (ICU) patients to raise blood pressure. Balancing risks and benefits of vasopressors is a challenge, particularly in older patients.

Objective  To determine whether reducing exposure to vasopressors through permissive hypotension (mean arterial pressure [MAP] target, 60-65 mm Hg) reduces mortality at 90 days in ICU patients aged 65 years or older with vasodilatory hypotension.

Design, Setting, and Participants  A multicenter, pragmatic, randomized clinical trial was conducted in 65 ICUs in the United Kingdom and included 2600 randomized patients aged 65 years or older with vasodilatory hypotension (assessed by treating clinician). The study was conducted from July 2017 to March 2019, and follow-up was completed in August 2019.

Interventions  Patients were randomized 1:1 to vasopressors guided either by MAP target (60-65 mm Hg, permissive hypotension) (n=1291) or according to usual care (at the discretion of treating clinicians) (n=1307).

Main Outcome and Measures  The primary clinical outcome was all-cause mortality at 90 days.

Results  Of 2600 randomized patients, after removal of those who declined or had withdrawn consent, 2463 (95%) were included in the analysis of the primary outcome (mean [SD] age 75 years [7 years]; 1387 [57%] men). Patients randomized to the permissive hypotension group had lower exposure to vasopressors compared with those in the usual care group (median duration 33 hours vs 38 hours; difference in medians, –5.0; 95% CI, –7.8 to –2.2 hours; total dose in norepinephrine equivalents median, 17.7 mg vs 26.4 mg; difference in medians, –8.7 mg; 95% CI, –12.8 to 4.6 mg). At 90 days, 500 of 1221 (41.0%) in the permissive hypotension compared with 544 of 1242 (43.8%) in the usual care group had died (absolute risk difference, 2.85%; 95% CI, 6.75 to 1.05; P=.15) (unadjusted relative risk, 0.93; 95% CI, 0.85-1.03). When adjusted for prespecified baseline variables, the odds ratio for 90-day mortality was 0.82 (95% CI, 0.68 to 0.98). Serious adverse events were reported for 79 patients (6.2%) in the permissive care group and 75 patients (5.8%) in the usual care group. The most common serious adverse events were acute renal failure (41 [3.2%] vs 33 [2.5%]) and supraventricular cardiac arrhythmia (12 [0.9%] vs 13 [1.0%]).

Conclusions and Relevance  Among patients 65 years or older receiving vasopressors for vasodilatory hypotension, permissive hypotension compared with usual care did not result in a statistically significant reduction in mortality at 90 days. However, the confidence interval around the point estimate for the primary outcome should be considered when interpreting the clinical importance of the study.

DOI: 10.1001/jama.2020.0930

Source: https://jamanetwork.com/journals/jama/fullarticle/2761427