Di Mussi Rosa, Spadaro Savino, Mirabella Lucia, Volta Carlo Alberto, Serio Gabriella, Staffieri Francesco, Dambrosio Michele, Cinnella Gilda, Bruno Francesco, Grasso Salvatore
Dipartimento dell'Emergenza e Trapianti d'Organo (DETO), Sezione di Anestesiologia e Rianimazione, Università degli Studi di Bari "Aldo Moro", Piazza Giulio Cesare 11, Bari, Italy.
Dipartimento di Morfologia, Chirurgia e Medicina Sperimentale, Sezione di Anestesiologia e Terapia Intensiva Universitaria, Università degli studi di Ferrara, Ferrara, Italy.
Crit Care. 2016 Jan 5;20:1. doi: 10.1186/s13054-015-1178-0.
Prolonged controlled mechanical ventilation depresses diaphragmatic efficiency. Assisted modes of ventilation should improve it. We assessed the impact of pressure support ventilation versus neurally adjusted ventilator assist on diaphragmatic efficiency.
Patients previously ventilated with controlled mechanical ventilation for 72 hours or more were randomized to be ventilated for 48 hours with pressure support ventilation (n =12) or neurally adjusted ventilatory assist (n = 13). Neuro-ventilatory efficiency (tidal volume/diaphragmatic electrical activity) and neuro-mechanical efficiency (pressure generated against the occluded airways/diaphragmatic electrical activity) were measured during three spontaneous breathing trials (0, 24 and 48 hours). Breathing pattern, diaphragmatic electrical activity and pressure time product of the diaphragm were assessed every 4 hours.
In patients randomized to neurally adjusted ventilator assist, neuro-ventilatory efficiency increased from 27 ± 19 ml/μV at baseline to 62 ± 30 ml/μV at 48 hours (p <0.0001) and neuro-mechanical efficiency increased from 1 ± 0.6 to 2.6 ± 1.1 cmH2O/μV (p = 0.033). In patients randomized to pressure support ventilation, these did not change. Electrical activity of the diaphragm, neural inspiratory time, pressure time product of the diaphragm and variability of the breathing pattern were significantly higher in patients ventilated with neurally adjusted ventilatory assist. The asynchrony index was 9.48 [6.38- 21.73] in patients ventilated with pressure support ventilation and 5.39 [3.78- 8.36] in patients ventilated with neurally adjusted ventilatory assist (p = 0.04).
After prolonged controlled mechanical ventilation, neurally adjusted ventilator assist improves diaphragm efficiency whereas pressure support ventilation does not.
ClinicalTrials.gov study registration: NCT02473172, 06/11/2015.
长时间的控制性机械通气会降低膈肌效率。辅助通气模式应能改善这种情况。我们评估了压力支持通气与神经调节通气辅助对膈肌效率的影响。
曾接受72小时或更长时间控制性机械通气的患者被随机分为两组，一组接受48小时的压力支持通气（n = 12），另一组接受神经调节通气辅助（n = 13）。在三次自主呼吸试验（0、24和48小时）期间测量神经通气效率（潮气量/膈肌电活动）和神经机械效率（对抗气道阻塞产生的压力/膈肌电活动）。每4小时评估呼吸模式、膈肌电活动和膈肌压力时间乘积。
在随机接受神经调节通气辅助的患者中，神经通气效率从基线时的27±19 ml/μV增加到48小时时的62±30 ml/μV（p<0.0001），神经机械效率从1±0.6增加到2.6±1.1 cmH₂O/μV（p = 0.033）。在随机接受压力支持通气的患者中，这些指标没有变化。接受神经调节通气辅助的患者，其膈肌电活动、神经吸气时间、膈肌压力时间乘积和呼吸模式变异性显著更高。压力支持通气患者的异步指数为9.48[6.38 - 21.73]，神经调节通气辅助患者为5.39[3.78 - 8.36]（p = 0.04）。
长时间控制性机械通气后，神经调节通气辅助可提高膈肌效率，而压力支持通气则不能。
ClinicalTrials.gov研究注册：NCT02473172，2015年11月6日。
