Oxygen Supplementation During Bronchoscopy: High Flow Versus Low Flow Oxygen

In general bronchoscopy is a safe procedure with low rate of complications. Indeed, contraindications to flexible bronchoscopy are mostly relative rather than absolute. This is the case of preexisting decreased blood oxygen levels which may be present in patients requiring further bronchopulmonary investigation. To avoid the deleterious effects of oxygen drops oxygen supplementation is recommended. The purpose of this study is to evaluate the efficiency and safety of oxygen supplementation obtained with the use of a high flow nasal cannula compared with a low flow nasal cannula during flexible bronchoscopy. Consecutive patients referred by their treating physician for bronchoscopy will be offered to take part in the study. Those who wish to participate and give their consent will be randomly assigned into one of two treatment groups (supplemental oxygen given via low flow nasal cannula or via high flow nasal cannula). Assignment to either treatment arm will not affect in any way the intended purpose of the bronchoscopy. All patients will be closely monitored during the procedure and 2 hours following its completion. Monitoring will be conducted, using strictly non-invasive measures.

High-flow nasal ventilation: This will be carried out using the Precision Flow device (Opti-Flow, Auckland, New Zealand). This device is intended to add warm moisture to breathing gases from an external source. Flow rate via the nasal cannula will be kept at 50 Liters/min and fractional inspired oxygen concentration will be set at 0.35

High-flow nasal ventilation: This will be carried out using the Precision Flow device (Opti-Flow, Auckland, New Zealand). This device is intended to add warm moisture to breathing gases from an external source. Flow rate via the nasal cannula will be kept at 50 Liters/min and fractional inspired oxygen concentration will be set at 0.35.

Low-flow nasal ventilation: This will be carried out using a regular nasal cannula fed with oxygen at flow rates from 2 to 6 liters/minute.

a numeric rating scale ranging from 1(excellent to 4(poor ) will be filled out by the patient after completion of the bronchoscopy

Inclusion Criteria: patients scheduled to undergo routine bronchoscopy for diagnostic purposes Exclusion Criteria: inability to give an informed consent nasal deformities

Albertini R, Harrel JH, Moser KM. Letter: Hypoxemia during fiberoptic bronchoscopy. Chest. 1974 Jan;65(1):117-8. doi: 10.1378/chest.65.1.117. No abstract available.

Matsushima Y, Jones RL, King EG, Moysa G, Alton JD. Alterations in pulmonary mechanics and gas exchange during routine fiberoptic bronchoscopy. Chest. 1984 Aug;86(2):184-8. doi: 10.1378/chest.86.2.184.

Du Rand IA, Blaikley J, Booton R, Chaudhuri N, Gupta V, Khalid S, Mandal S, Martin J, Mills J, Navani N, Rahman NM, Wrightson JM, Munavvar M; British Thoracic Society Bronchoscopy Guideline Group. British Thoracic Society guideline for diagnostic flexible bronchoscopy in adults: accredited by NICE. Thorax. 2013 Aug;68 Suppl 1:i1-i44. doi: 10.1136/thoraxjnl-2013-203618. No abstract available.

Roca O, Masclans JR, Laborda C, Sacanell J, Serra J. High-flow nasal cannula improves oxygenation in hypoxemic respiratory failure. Intensive Care Med 2007; 33:S86

Williams AB, Ritchie JE, Gerard C. Evaluation of a high-flow nasal oxygen delivery system: gas analysis and pharyngeal pressures. Intensive Care Med 2006; 32: S219

Lomas C, Roca O, Alvarez A, Masclans JR. Fibroscopy in patients with hypoxemic respiratory insufficiency: Utility of the high-flow nasal cannula. Respr Med (CME) 2009; 2: 121-124

Lucangelo U, Vassallo FG, Marras E, Ferluga M, Beziza E, Comuzzi L, Berlot G, Zin WA. High-flow nasal interface improves oxygenation in patients undergoing bronchoscopy. Crit Care Res Pract. 2012;2012:506382. doi: 10.1155/2012/506382. Epub 2012 May 20.