The Use of Non-invasive Respiratory Assistance to Facilitate Bronchofiberoscopy Performance in Patients With Hypoxemic (Type One) Respiratory Failure

Bronchofiberoscopy (FOB) is a minimally invasive procedure that has been commonly performed for many years in pneumological patients and in patients requiring intensive medical care.inistered to let patients tolerate FOB is an additional factor for derangement of blood gases. FB is usually performed with oxygen supplementation administered through standard nasal cannula. Due to increasing number of seriously ill, patient with respiratory failure, pure oxygen support is frequently insufficient to assure accurate oxygenation and prevent hypercapnia in patients requiring FOB. Up till now, many of those patients have been disqualified or intubated from FOB due to unfavorable risk to benefits balance.

NIV assures normal minute ventilation in patients with decreased respiratory drive, prevents collapsing of the peripheral airways, prevents atelectasis development, facilitates alveoli recruitment, increases vital capacity and lung susceptibility, as well as decrease heart workload. NIV may enable therapeutic FOB performance in patients with alveolar proteinosis without the need for intubation. NIV allows to perform safe bronchofiberoscopy in both diagnostic and therapeutic indications in patients with exacerbation of respiratory failure as well as in patients with severe chronic respiratory failure.

HFNC is another innovative method of respiratory support, which generates turbulent flow in patient's nasopharyngeal cavity and facilitates precise settings of high oxygen concentrations FiO2 up to 1 (100%). Obtained high flow is associated with generation of positive airway pressure, which additionally recruits alveoli and reduces atelectasis, which is partially similar to NIV and may give additional benefits to treatment of respiratory failure. Preliminary data indicate that both of described methods have a potential role in increasing the safety of FOB examinations in patients with mild to moderate respiratory failure. However, as of today it has not been clearly supported by scientific evidence, whether there are differences in the indications, contraindications, complications risk. As so far there is lack of evidence which would clearly indicate the target population which would benefit mostly from NIV-FOB or HFNC-FOB.

Additionally, investigators do not currently know universal settings of both devices which could be used initially and universally during FOB in patients with different severity of respiratory failure. In patients with severe respiratory failure, in some cases it is compulsory to intubate patient in order to perform a safe bronchoscopy. In cases of patient who have not been intubated, FOB could cause exacerbation of underlying respiratory failure, which may require intubation and ICU transfer.

This is a multicenter international three-arm Randomized Controlled Trial (RCT) performed in departments which deal with patients suffering from respiratory failure: respiratory intensive care unit (RICU), bronchoscopic theatre- form patients treated in other departments such as internal medicine departments, cardiology etc, pulmonary ward and ICU departments in apriori not intubated patients.