The Effects of Targeted Mild Hypercapnia on Right Ventricular Function After Out-of-Hospital Cardiac Arrest: A Substudy of the Targeted Therapeutic Mild Hypercapnia After Resuscitated Cardiac Arrest Trial.

RV dysfunction is common after cardiac arrest and may be associated with poor outcomes.

心脏骤停后RV功能障碍很常见，可能与不良结果有关。

research_question

Does targeting mild hypercapnia after out-of-hospital cardiac arrest (OHCA) adversely affect RV function, and is RV failure after OHCA associated with increased mortality?

针对院外心脏骤停（OHCA）后的轻度高碳酸血症是否会对右心室功能产生不利影响，以及OHCA后的右心室衰竭是否与死亡率增加有关？

study_design_and_methods

In this single-center, preplanned substudy of the Targeted Therapeutic Mild Hypercapnia After Resuscitated Cardiac Arrest (TAME) trial, patients were randomized to mild hypercapnia (Paco2, 50-55 mm Hg) or normocapnia (Paco2, 35-45 mm Hg) for 24 hours.

在这项针对复苏后心脏骤停患者靶向治疗轻度高碳酸血症（TAME）试验的单中心、预先计划的子研究中，患者被随机分配到轻度高碳酸血症（Paco2，50-55毫米汞柱）或正常碳酸血症（Paco2，35-45毫米汞柱）治疗24小时。

Transthoracic echocardiography was performed shortly after ICU admission, during and after the intervention period.

在ICU入院后不久、干预期间以及干预后，进行了经胸超声心动图检查。

Time-matched right heart catheterization (RHC) was performed when available.

在可行的情况下，进行了时间匹配的右心导管检查（RHC）。

RV systolic function was assessed with tricuspid annular plane systolic excursion (TAPSE), S', and fractional area change (FAC), with 2 of 3 measurements less than abnormal thresholds defined as dysfunction.

通过三尖瓣环平面收缩期位移（TAPSE）、S'和分数面积变化（FAC）评估右心室收缩功能，其中2项或3项测量值低于定义为功能障碍的异常阈值。

RV failure was defined as RV systolic dysfunction combined with a cardiac index of < 2.0 L/min/m2 and central venous pressure of > 12 mm Hg.

右心室衰竭定义为右心室收缩功能障碍与心指数小于2.0 L/min/m2以及中心静脉压大于12 mm Hg的结合。

Results

A total of 111 patients were randomized and evaluated with echocardiography.

共有111名患者被随机分组并使用超声心动图进行了评估。

RHC was performed in 84 patients.

在84名患者中进行了右心导管检查（RHC）。

TAPSE similarly was reduced in both treatment groups at ICU admission.

TAPSE在ICU入院时在两组治疗中均有所降低。

During the intervention, TAPSE, S', and FAC were higher in the hypercapnia group (P < .05).

在干预期间，高碳酸血症组的TAPSE、S'和FAC更高（P < .05）。

Accordingly, 13 patients (25%) in the hypercapnia group demonstrated RV systolic dysfunction compared with 37 patients (64%) in the normocapnia group (P < .001).

因此，高碳酸血症组中有13名患者（25%）表现出右心室收缩功能障碍，而在正常碳酸血症组中有37名患者（64%）表现出该症状（P < .001）。

RV failure was present in 30 patients: 8 patients in the hypercapnia group and 22 patients in the normocapnia group (P = .011).

有30名患者出现右心室衰竭：高碳酸血症组有8名患者，正常碳酸血症组有22名患者（P = .011）。

RV failure was associated with increased 6-month mortality (hazard ratio, 2.89; 95% CI, 1.37-6.10; P = .005).

右心室衰竭与6个月死亡率增加相关（风险比，2.89；95%置信区间，1.37-6.10；P = .005）。

interpretation

Among patients resuscitated from OHCA, targeting mild hypercapnia compared with normocapnia was not associated with worsened RV function, but rather with less RV dysfunction and failure.

在从院外心脏骤停复苏的患者中，与正常二氧化碳血症相比，目标轻度高碳酸血症并未与右心室功能恶化相关，反而与较少的右心室功能障碍和衰竭相关。

RV failure was associated with increased 6-month mortality.

右心室衰竭与6个月死亡率增加相关。

clinical_trial_registration

ClinicalTrials.gov; No.: NCT03114033; URL: www.

ClinicalTrials.gov; 编号：NCT03114033; 网址：www.

clinicaltrials

gov.

5年总生存率为65%，95%置信区间为58-72%。