Department of Anaesthesiology and Intensive Care, Region Västra Götaland, Sahlgrenska University Hospital, Gothenburg, Sweden.
Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Acta Anaesthesiol Scand. 2024 Aug;68(7):932-939. doi: 10.1111/aas.14434. Epub 2024 May 19.
Assisted mechanical ventilation may alter the pressure profile in the thorax compared to normal breathing, which can affect the blood flow to and from the heart. Studies suggest that in patients with severe lung disease, airway pressure release ventilation (APRV) may be haemodynamically beneficial compared to other ventilator settings. The primary aim of this study was to investigate if APRV affects cardiac index in intubated intensive care patients without severe lung disease when compared to pressure support ventilation (PSV). The secondary aim comprised potential changes in other haemodynamic and ventilatory parameters.
Twenty patients were enrolled in the intensive care unit (ICU) at Sahlgrenska University Hospital. Eligible patients met the inclusion criteria; 18 years of age or above, intubated and mechanically ventilated, triggering and stable on PSV mode, with indwelling haemodynamic monitoring via a pulse-induced continuous cardiac output (PiCCO) catheter. The study protocol started with a 30-min interval on PSV mode, followed by a 30-min interval on APRV mode, and finally a 30-min interval back on PSV mode. At the end of each interval, PiCCO outputs, ventilator outputs, arterial and venous blood gas analyses, heart rate and central venous pressure were recorded and compared between modes.
There was no significant difference in cardiac index (3.42 vs. 3.39 L/min/m) between PSV and APRV, but a significant increase in central venous pressure (+1.0 mmHg, p = .027). Furthermore, we found a significant reduction in peak airway pressure (-3.16 cmHO, p < .01) and an increase in mean airway pressure (+2.1 cmHO, p < .01). No statistically significant change was found in oxygenation index (partial pressure of O [pO]/fraction of inspired oxygen) nor in other secondary outcomes when comparing PSV and APRV. There was no significant association between global end-diastolic volume index and cardiac index (R = 0.0089) or central venous pressure (R = 0.278). All parameters returned to baseline after switching the ventilator mode back to PSV.
We could not detect any changes in cardiac index in ICU patients without severe lung disease during APRV compared to PSV mode, despite lower peak airway pressure and increased mean airway pressure.
与正常呼吸相比，辅助机械通气可能会改变胸部压力分布，从而影响心脏的血液流向和流出。研究表明，在患有严重肺部疾病的患者中，与其他通气模式相比，气道压力释放通气（APRV）可能具有血流动力学益处。本研究的主要目的是研究与压力支持通气（PSV）相比，APRV 是否会影响无严重肺部疾病的气管插管重症监护患者的心指数。次要目的包括研究潜在的其他血流动力学和通气参数变化。
本研究共纳入了萨赫勒格伦斯卡大学医院重症监护病房（ICU）的 20 名患者。符合入选标准的患者为：年龄 18 岁及以上，气管插管并接受机械通气，触发并稳定在 PSV 模式，通过留置的脉搏指示连续心输出量（PiCCO）导管进行血流动力学监测。研究方案首先进行 30 分钟 PSV 模式，然后进行 30 分钟 APRV 模式，最后恢复 30 分钟 PSV 模式。在每个间隔结束时，记录 PiCCO 输出、呼吸机输出、动脉和静脉血气分析、心率和中心静脉压，并比较各模式之间的差异。
PSV 和 APRV 之间的心指数（3.42 vs. 3.39 L/min/m）没有显著差异，但中心静脉压（+1.0 mmHg，p=0.027）显著升高。此外，我们发现气道峰压（-3.16 cmHO，p<0.01）显著降低，平均气道压（+2.1 cmHO，p<0.01）升高。比较 PSV 和 APRV 时，氧合指数（pO/FiO）和其他次要结局均无统计学意义的变化。全球舒张末期容积指数与心指数（R=0.0089）或中心静脉压（R=0.278）之间无显著相关性。切换回 PSV 通气模式后，所有参数均恢复至基线。
在无严重肺部疾病的 ICU 患者中，与 PSV 模式相比，APRV 并未检测到心指数的变化，尽管气道峰压降低，平均气道压升高。
