Service de Réanimation Polyvalente, CHU Rangueil, 1 Avenue Jean Poulhès, Pôle d'Anesthésie et Réanimation, TSA 50032, 31059, Toulouse Cedex 9, France.
Department of Anaesthesiology and Critical Care Unit, University Hospital of Toulouse, 31059, Toulouse Cedex 9, France.
Crit Care. 2019 Jan 7;23(1):2. doi: 10.1186/s13054-018-2288-2.
Prolonged weaning is a major issue in intensive care patients and tracheostomy is one of the last resort options. Optimized patient-ventilator interaction is essential to weaning. The purpose of this study was to compare patient-ventilator synchrony between pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA) in a selected population of tracheostomised patients.
We performed a prospective, sequential, non-randomized and single-centre study. Two recording periods of 60 min of airway pressure, flow, and electrical activity of the diaphragm during PSV and NAVA were recorded in a random assignment and eight periods of 1 min were analysed for each mode. We searched for macro-asynchronies (ineffective, double, and auto-triggering) and micro-asynchronies (inspiratory trigger delay, premature, and late cycling). The number and type of asynchrony events per minute and asynchrony index (AI) were determined. The two respiratory phases were compared using the non-parametric Wilcoxon test after testing the equality of the two variances (F-Test).
Among the 61 patients analysed, the total AI was lower in NAVA than in PSV mode: 2.1% vs 14% (p < 0.0001). This was mainly due to a decrease in the micro-asynchronies index: 0.35% vs 9.8% (p < 0.0001). The occurrence of macro-asynchronies was similar in both ventilator modes except for double triggering, which increased in NAVA. The tidal volume (ml/kg) was lower in NAVA than in PSV (5.8 vs 6.2, p < 0.001), and the respiratory rate was higher in NAVA than in PSV (28 vs 26, p < 0.05).
NAVA appears to be a promising ventilator mode in tracheotomised patients, especially for those requiring prolonged weaning due to the decrease in asynchronies.
延长撤机时间是重症监护患者的一个主要问题，而气管切开术是最后的选择之一。优化患者与呼吸机的相互作用对于撤机至关重要。本研究的目的是比较压力支持通气（PSV）和神经调节辅助通气（NAVA）在选定的气管切开患者人群中的患者与呼吸机同步性。
我们进行了一项前瞻性、连续、非随机和单中心研究。在随机分配的情况下，记录了 60 分钟的气道压力、流量和膈肌电活动，在 PSV 和 NAVA 期间各记录了 60 分钟，并对每种模式分析了 8 分钟的 1 分钟。我们寻找了宏观失步（无效、双重和自动触发）和微观失步（吸气触发延迟、过早和晚期循环）。每分钟确定失步事件的数量和类型以及失步指数（AI）。使用非参数 Wilcoxon 检验比较两个呼吸相，在测试两个方差相等（F 检验）之后。
在分析的 61 名患者中，NAVA 的总 AI 低于 PSV 模式：2.1%比 14%（p<0.0001）。这主要是由于微失步指数降低：0.35%比 9.8%（p<0.0001）。两种通气模式下宏观失步的发生情况相似，除了双重触发增加外，NAVA 中双重触发增加。NAVA 的潮气量（ml/kg）低于 PSV（5.8 比 6.2，p<0.001），而 NAVA 的呼吸频率高于 PSV（28 比 26，p<0.05）。
NAVA 似乎是气管切开患者有前途的通气模式，特别是对于那些由于失步减少而需要长时间撤机的患者。
