Development of a closed-loop device for phrenic nerve stimulation to enable a new approach of intensive care ventilatory support – (DIA-STIM)

机械通气（MV）是唯一已确立的用于急性呼吸衰竭患者的救生干预方法。在这种呼吸支持期间，横膈膜保持不活动，并受到称为“呼吸机诱导的呼吸功能障碍”（VIDD）的病理生理综合征的威胁，这是导致脱机失败的重要因素，加重了通气患者的发病率和死亡率。几项研究表明，在MV期间保持一定程度的膈肌活动（例如，通过膈神经起搏）可以保护膈肌功能并抑制其萎缩，这可能导致使用呼吸机的天数减少。传统的膈神经刺激已经建立了多年，特别是在患有严重神经病变如截瘫的患者中。但是到目前为止，这些使用经胸开放方法植入到椎间盘表面上的大型设备仅限于选定的患者队列，长期依赖于这种刺激设备。可以得出结论，在许多难以脱机的患者中，VIDD发生在可以建立自主呼吸之前。到目前为止，呼吸机设置对患者呼吸努力的适应仍然是重症监护中的手动过程，这关键取决于床边人类治疗师的存在。作为一种解决问题的方法，呼吸机设置的即时呼吸调整，能够防止未应答的呼吸努力结合膈神经刺激的膈肌活动，可以防止急性或围手术期设置的VIDD。因此，拟议的实验将检查呼吸努力的即时调整的可行性，以模仿围手术期重症监护中的自主呼吸;到目前为止，插管患者的自主呼吸通常是不可能的临床情况。ICU兼容的膈肌刺激程序可以最大限度地减少患者对MV的需求。因此，所提出的工作将结合联合收割机的好处，从传统的膈起搏与临时膈肌刺激在自动调节呼吸分钟量。

Mechanical ventilation (MV) is the only established method used as a life-saving intervention in patients with acute respiratory failure. During this ventilatory support, the diaphragm stays inactive and is threatened by a pathophysiological syndrome called "ventilator-induced diaphragmatic dysfunction" (VIDD), an important contributor to weaning failure aggravating morbidity and mortality of ventilated patients. Several studies indicated that maintaining a certain degree of diaphragmatic activity during MV (e.g. by phrenic nerve pacing) could preserve diaphragm function and inhibit its atrophy, which could result in fewer days on the ventilator. Conventional phrenic nerve stimulation has been established for years, especially in patients suffering from severe neurological pathologies like paraplegia. But so far these large-scale devices, which are implanted on the diaphragmatic surface using a transthoracic open approach, are limited to a selected patient cohort, with long-term dependency on this stimulation device. It can be concluded that in many difficult-to-wean patients, VIDD occurs before spontaneous breathing can be established. Till now, the adaptation of ventilator settings to patients’ breathing efforts is still a manual procedure in intensive care, which crucially depends on the presence of a bedside human therapist. As a problem-solving approach, immediate breath-by-breath adaption of respirator settings enabling prevention from unanswered breathing efforts combined with phrenic nerve-stimulated diaphragm activity could prevent VIDD in an acute or perioperative setting.Therefore, the proposed experiments will examine the feasibility of an immediate adaption of breathing efforts to mimic spontaneous breathing in perioperative intensive care; a clinical situation where spontaneous breathing has often been impossible in intubated patients till now. An ICU-compatible procedure of diaphragm stimulation could minimize patients’ need for MV. Hence, the proposed work will combine benefits from conventional phrenic pacing with temporary diaphragm stimulation in an automated regulation of the respiratory minute volume.