Department of Intensive Care, Academic Medical Centre, Amsterdam, The Netherlands; Laboratory of Experimental Intensive Care and Anesthesiology, Amsterdam, The Netherlands.
Department of Intensive Care, Academic Medical Centre, Amsterdam, The Netherlands.
Resuscitation. 2018 Aug;129:29-36. doi: 10.1016/j.resuscitation.2018.04.040. Epub 2018 May 12.
Mechanical ventilation practices in patients with cardiac arrest are not well described. Also, the effect of temperature on mechanical ventilation settings is not known. The aims of this study were 1) to describe practice of mechanical ventilation and its relation with outcome 2) to determine effects of different target temperatures strategies (33 °C versus 36 °C) on mechanical ventilation settings.
This is a substudy of the TTM-trial in which unconscious survivors of a cardiac arrest due to a cardiac cause were randomized to two TTM strategies, 33 °C (TTM33) and 36 °C (TTM36). Mechanical ventilation data were obtained at three time points: 1) before TTM; 2) at the end of TTM (before rewarming) and 3) after rewarming. Logistic regression was used to determine an association between mechanical ventilation variables and outcome. Repeated-measures mixed modelling was performed to determine the effect of TTM on ventilation settings.
Mechanical ventilation data was available for 567 of the 950 TTM patients. Of these, 81% was male with a mean (SD) age of 64 (12) years. At the end of TTM median tidal volume was 7.7 ml/kg predicted body weight (PBW)(6.4-8.7) and 60% of patients were ventilated with a tidal volume ≤ 8 ml/kg PBW. Median PEEP was 7.7cmHO (6.4-8.7) and mean driving pressure was 14.6 cmHO (±4.3). The median FiO fraction was 0.35 (0.30-0.45). Multivariate analysis showed an independent relationship between increased respiratory rate and 28-day mortality. TTM33 resulted in lower end-tidal CO (Pgroup = 0.0003) and higher alveolar dead space fraction (Pgroup = 0.003) compared to TTM36, while PCO levels and respiratory minute volume were similar between groups.
In the majority of the cardiac arrest patients, protective ventilation settings are applied, including low tidal volumes and driving pressures. High respiratory rate was associated with mortality. TTM33 results in lower end-tidal CO levels and a higher alveolar dead space fraction compared to TTTM36.
心脏骤停患者的机械通气实践情况描述得并不充分。此外，温度对机械通气设置的影响也尚不清楚。本研究的目的是：1）描述机械通气的实践情况及其与结局的关系；2）确定不同目标温度策略（33°C 与 36°C）对机械通气设置的影响。
这是 TTM 试验的一项子研究，其中因心源性原因导致心脏骤停的无意识幸存者被随机分配至两种 TTM 策略，33°C（TTM33）和 36°C（TTM36）。在三个时间点获得机械通气数据：1）在 TTM 之前；2）在 TTM 结束时（复温前）；3）复温后。采用逻辑回归来确定机械通气变量与结局之间的关联。采用重复测量混合模型来确定 TTM 对通气设置的影响。
共有 950 例 TTM 患者中的 567 例患者可提供机械通气数据。其中，81%为男性，平均（SD）年龄为 64（12）岁。在 TTM 结束时，中位潮气量为 7.7ml/kg 预测体重（PBW）（6.4-8.7），60%的患者潮气量≤8ml/kg PBW。中位呼气末正压（PEEP）为 7.7cmHO（6.4-8.7），平均驱动压为 14.6cmHO（±4.3）。中位吸入氧分数（FiO ）为 0.35（0.30-0.45）。多变量分析显示，呼吸频率增加与 28 天死亡率存在独立关系。与 TTM36 相比，TTM33 导致呼气末 CO 更低（Pgroup=0.0003）和肺泡死腔分数更高（Pgroup=0.003），而两组间 PCO 水平和呼吸分钟通气量相似。
在大多数心脏骤停患者中，应用了保护性通气设置，包括低潮气量和低驱动压。高呼吸频率与死亡率相关。与 TTM36 相比，TTM33 导致呼气末 CO 水平更低和肺泡死腔分数更高。
