The first patient has been successfully included in the DE-RISK WF II study at the coordinating center, Hôpitaux Universitaires Pitié Salpêtrière, in Paris.

The DE-RISK WF II study is a multicenter, multinational clinical evidence study to validate RESPINOR DXT’s performance to identify patients at increased risk of weaning failure.

RESPINOR DXT is a novel medical device that provides non-invasive, continuous monitoring of the diaphragm, our main breathing muscle.

There is compelling evidence that diaphragm weakness is frequent in critically ill patients and is associated with increased risk of weaning failure from mechanical ventilation (MV): During weaning, evaluating parameters such as respiratory rate, tidal volume, and blood saturation, allow the intensive care clinician to assess the stability of the cardiovascular system and adequate oxygenation and pulmonary function. However, by not having an objective measure of the diaphragm, it is difficult for the physicians to identify whether the patient has ventilator induced diaphragm dysfunction or not. If the diaphragm is too weak at the time of weaning, the accessory respiratory muscles can increase their contribution to compensate for any deficiency of the diaphragm, and consequently all vital signs look acceptable. When the patient is extubated, the accessory respiratory muscles do not have the same endurance as the diaphragm and will consequently fatigue. Thus, delayed weaning failure and reintubation may occur in patients who have unidentified diaphragm dysfunction at the time of weaning.

The risks associated with reintubation are severe and include increased cardiac and respiratory complications, prolonged MV support, prolonged length of ICU and hospital stay, increased mortality, and higher costs. Furthermore, studies show that patients who have prolonged stay on the ventilator have poor prognosis and average treatment costs of €300k per patient per year. Unroe et al. (2010) followed 126 patients weaning from mechanical ventilation, and after one year, 44% of patients on prolonged mechanical ventilation were deceased, and only 9% of the survivors were in good health.

Today, it is well established that diaphragm ultrasound may help diagnose diaphragm dysfunction and predict weaning failure. The literature has documented that monitoring of the diaphragm during weaning can reduce time on mechanical ventilation with 25%. However, standard ultrasound methods require skilled operators and continuous monitoring is not feasible. The introduction of RESPINOR DXT can represent a paradigm shift.

The aim of the DE-RISK WF II study is to develop predictive indices to optimize the time patients are on MV by establishing cut-off values of diaphragm excursion ​​to predict weaning outcome. DXT has the potential to optimize extubation timing, reduce re-intubation rate, improve patient outcomes, and reduce healthcare costs.

The DE-RISK WF II study is a follow-up study in 7 centers in France and Norway with 145 patients with an improved, close-to-the-commercial version of DXT, including a new algorithm for depth selection, a new graphical user interface (GUI), quality control for signal, and a new DXT tape solution.

Primary endpoint: Difference in the rate of weaning failure between patients with a diaphragm excursion (DE) < 1.0 cm compared to those with a DE > 1.1 cm. Median DE measurements taken during the second minute of the SBT will be used in the analysis to ensure that we identify ventilator-induced diaphragm dysfunction early. The hypothesis is that patients with DE < 1.0 cm will have a significantly higher rate of weaning failure compared to those with a DE > 1.1. The relative risk (RR) statistic will be used to assess the null hypothesis of equality.

Clinical application: If DE < 1.0 cm at time of weaning, the risk of weaning failure is increased since the diaphragm has gotten too weak to enable the patient to breathe on their own. The physicians can now initiate rehabilitation of the diaphragm prior to weaning.

The study is expected to be completed in Q2 2023.

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