Lung Aeration After Flexible Bronchoscopy in Intubated Critically Ill Patients

Assessment of Lung Aeretion After Flexible Bronchoscopy for Secretion Removal in Intubated Critically Ill Patients Receiving or Not a Recruiting Maneuver Soon After the Procedure: an Observational Physiological Study

In patients suffering from acute respiratory failure, ineffective cough and the consequent retention of secretions are common clinical problems, which often lead to the need for tracheostomy for the sole purpose of aspiration of secretions from the airways.

Mechanically ventilated critically ill patients often have impaired mucus transport which is associated with secretion retention and subsequent development of pneumonia. The accumulation of tracheobronchial secretions in ventilated patients in ICU is due not only to an increased production, but also to a decreased clearance. In the event that secretions occlude a bronchus, an atelectasis of the lung parenchyma is created downstream. Therefore, it is often necessary to perform a flexible bronchoscopy (FOB) to proceed with the removal of the secretion plug. After its removal, the lung is supposed to be reventilated and recruited.

In intubated ICU patients, the application of a recruiting maneuver (RM) is commonly used to reopen the collapsed lung in patients with Acute Respiratory Distress Syndrome or in case of atelectasis in other clinical conditions. However, no studies have so far investigated the role of the application of a RM after a FOB performed to remove a secretion plug in intubated ICU patients.

This observational and physiological study aims to assess if the application of a RM would modify the lung aeration soon after an FOB to remove secretion plug (first outcome). Moreover, the study aims to assess if EIT could be an additional bedside imaging tool to monitor modifications of lung ventilation and aeration during and after a flexible bronchoscopy, as compared with both chest-X-ray and lung ultrasound.

Inclusion Criteria:

• invasive mechanical ventilation
• need for flexible bronchoscopy to remove secretion plug from the airway

Exclusion Criteria:

• hemodynamic instability, (i.e. systolic arterial pressure <90 mmHg or mean systolic pressure <65 mmHg despite fluid repletion);
• need for vasoactive agents, i.e. vasopressin or epinephrine at any dosage, or norepinephrine >0.3 mcg/kg/min or dobutamine>5 mcg/kg/min;
• life-threatening arrhythmias or electrocardiographic signs of ischemia;
• contraindications to placement of Electrical Impedance Tomography belt, Lung UltraSound or application of a Recruiting Maneuver (i.e., pneumothorax, pulmonary emphysema, chest burns or thoracic surgery within 1 week);
• inclusion in other research protocols.