Can fiberoptic bronchoscopy be applied to critically ill patients treated with noninvasive ventilation for acute respiratory distress syndrome? Prospective observational study

Abstract

BackgroundNoninvasive ventilation (NIV) is a cornerstone for the treatment of acute respiratory failure of various etiologies. Using NIV is discussed in mild-to-moderate acute respiratory distress syndrome (ARDS) patients (PaO2/FiO2 > 150). These patients often have comorbidities that increase the risk for bronchoscopy related complications. The primary outcome of this prospective observational study was to evaluate the feasibility, safety and contribution in diagnosis and/or modification of the ongoing treatment of fiberoptic bronchoscopy (FOB) in patients with ARDS treated with NIV.MethodsARDS patients treated with NIV and who require FOB as the diagnostic or therapeutic procedure were included the study. Intensive care ventilators or other dedicated NIV ventilators were used. NIV was applied via simple oro-nasal mask or full-face mask. Pressure support or inspiratory positive airway pressure (IPAP), external positive end expiratory pressure (PEEP) or expiratory positive airway pressure (EPAP) levels were titrated to achieve an expiratory tidal volume of 8 to 10 ml/kg according to ideal body weight, SpO2 > 90 % and respiratory rate below 25/min.ResultsTwenty eight subjects (mean age 63.3 ± 15.9 years, 15 men, 13 women, PaO2/FiO2 rate 145 ± 50.1 at admission) were included the study. Overall the procedure was well tolerated with only 5 (17.9 %) patients showing minor complications. There was no impairment in arterial blood gas and cardiopulmonary parameters after FOB. PaO2/FiO2 rate increased from 132.2 ± 49.8 to 172.9 ± 63.2 (p = 0.001). No patient was intubated within 2 h after the bronchoscopy. 10.7, 32.1 and 39.3 % of the patients required invasive mechanical ventilation after 8 h, 24 h and 48 h, respectively. Bronchoscopy provided diagnosis in 27 (96.4 %) patients. Appropriate treatment was decided according to the results of the bronchoscopic sampling in 20 (71.4 %) patients.ConclusionFOB under NIV could be considered as a feasible tool for diagnosis and guide for treatment of patients with ARDS treated via NIV in intensive care units. However, FOB-correlated life-treathening complications in severe hypoxemia should not be forgotten. Furthermore, further controlled studies involving a larger series of homogeneous ARDS patients undergoing FOB under NIV are needed to confirm these preliminary findings.

Is ventilated hospital-acquired pneumonia a worse entity than ventilator-associated pneumonia?

“…Due to these potential deleterious complications, the benefits of this technique are not clear [1]. Moreover, while it is easy and feasible to access the lower airways through an endotracheal tube, performing a bronchoscopy in a spontaneously breathing patient can be challenging, although several reports have proved the safety of this technique in patients on NIV or HFOT [39][40][41][42].…”

Invasive and non-invasive diagnostic approaches for microbiological diagnosis of hospital-acquired pneumonia

“…A key point when discussing invasive vs. non-invasive tactics in HAP is the feasibility and safety of performing a fiberoptic-bronchoscopy. Several reports show that fiberoptic-bronchoscopy, followed by BAL or mini-BAL, can be conducted in patients with acute respiratory failure and community- and healthcare-acquired pneumonia and is even safer when non-invasive ventilation and high-flow oxygen therapy are applied [34–39]. In a landmark trial, Azoulay et al showed that an invasive approach had a similar rate of intubation to a non-invasive approach in non-ventilated, immunosuppressed patients with acute respiratory failure [40].…”

How should we monitor patients with acute respiratory failure treated with noninvasive ventilation?

“…FOB for clearing airways helps to improve ventilation and oxygen exchange, thereby avoiding intubation [105]. In special circumstances FOB with or without transbronchial biopsy may be needed for differential diagnosis such as cytopathologic analysis in diffuse interstitial infiltrates [106,107]. Other indications are atelectasis, possibility of lung cancer and assessment of the tracheobronchial tree for tracheobronchial rupture/fistula after surgery or chest trauma.…”

“…For that reason, close ABG analysis should be performed and adjustments in NIV settings including FIO 2 should be considered for the maintenance of adequate gas exchange. Other FOB-related complications such as gastric distention, aspiration, fever, pneumothorax and new worsening of pre-existing or new-onset cardiac arrhythmia can be seen, which are seldom clinically important [105,107]. However, it is crucial to perform FOB with expert staff in the ICU under close monitoring, as there may be need for emergency intubation or invasive mechanical ventilation.…”