Flexible bronchoscopy (FB) in intubated patients on mechanical ventilation increases airway resistance. During FB, two ventilatory strategies are possible: maintaining tidal volume (V T) while maintaining baseline CO2 or allowing reduction of V T. The former strategy carries risk of hyperinflation due to expiratory flow limitation with FB. The aim of the authors was too study end expiratory lung volume (EELV) during FB of intubated subjects while limiting V T.
We studied 16 subjects who were intubated on mechanical ventilation and required FB. Changes in EELV were measured by respiratory inductance plethysmography. Ventilator mechanics, EELV, and arterial blood gases, were measured.
FB insertions decreased EELV in 64% of cases (−325±371 mL) and increased it in 32% of cases (65±59 mL). Suctioning decreased EELV in 76% of cases (−120±104 mL) and increased it in 16% of cases (29±33 mL). Respiratory mechanics were unchanged. Pre-FB and post-FB, PaO2 decreased by 61±96 mm Hg and PaCO2 increased by 15±7 mm Hg.
There was no clinically significant increase in EELV in any subject during FB. Decreases in EELV coincided with FB-suctioning maneuvers. Peak pressure limiting ventilation protected the subject against hyperinflation with a consequent, well-tolerated reduction in V T, and hypercapnea. Suctioning should be limited, especially in patients vulnerable to derecruitment effect.
*Department of Medicine, Hofstra Northwell School of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, New Hyde Park
‡Department of Medicine, Albany Medical Center, Albany, NY
†Department of Medicine, Einstein Healthcare Network, East Norriton, PA
E.S., P.D., and P.H.M.: contributed to the study design and measurement strategy of the study. Y.Y.G. and P.H.M.: responsible for data analysis and manuscript preparation.
Disclosure: There is no conflict of interest or other disclosures.
Reprints: Yonatan Y. Greenstein, MD, Department of Medicine, Hofstra Northwell School of Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, 410 Lakeville Road, Suite 107, New Hyde Park, NY 11040 (e-mail: firstname.lastname@example.org).
Received June 28, 2016
Accepted November 16, 2016