Use of a ventilatory strategy to prevent atelectasis (VESPA) during peripheral bronchoscopy under general anesthesia has been shown to reduce the incidence of atelectasis, according to clinical trial results published in Chest.
Recognizing that atelectasis negatively affects the results of peripheral bronchoscopy, the investigators sought to explore whether the use of VESPA can decrease the incidence of this adverse event. It is well known that the occurrence of atelectasis can obscure targets and create false-positive radial-probe endobronchial ultrasound (RP-EBUS) images, thus leading to nondiagnostic sampling.
The VESPA trial (ClinicalTrials.gov identifier: NCT04311723), a prospective, randomized controlled study was conducted at the University of Texas MD Anderson Cancer Center in Houston, Texas, and at Banner Boswell Medical Center in Gilbert, Arizona. Patients undergoing bronchoscopy were randomized to receive 1 of 2 treatments prior to bronchoscopy: (1) standard ventilation, in which participants received ventilation through a laryngeal mask airway with a tidal volume (VT) of 6 to 8 mL/kg of ideal body weight (IBW), fraction of inspired oxygen (FiO2) of 100%, and no positive expiratory pressure (PEEP); or (2) VESPA, in which patients received ventilation through an endotracheal tube with a VT of 6 to 8 mL/kg of IBW, FiO2 of <100% (which was titrated as low as possible to maintain an oxygen saturation of >94%), and PEEP of 8 to 10 cm of H2O.
All of the study participants underwent chest computed tomography (CT) and a survey for atelectasis with RP-EBUS after artificial airway insertion (time 1) and 20 to 30 minutes later (time 2). A blinded radiologist reviewed all of the chest CT scans, and 3 independent, blinded readers evaluated all of the RP-EBUS images. The primary study endpoint was the proportion of patients with any atelectasis (either unilateral or bilateral) at time 2, based on chest CT.
A total of 76 individuals were analyzed and randomized in a 1:1 ratio, with 38 participants in each group (VESPA group and control group). The percentage of participants with any atelectasis (either bilateral or unilateral) by chest CT at time 2 was 84.2% (95% CI, 72.6%-95.8%) in the control group vs 28.9% (95% CI, 15.4%-45.9%) in the VESPA group (P <.0001). Further, the proportion of patients with bilateral atelectasis at time 2 was 71.1% (95% CI, 56.6%-85.5%) in the control arm compared with 7.9% (95% CI, 1.7%-21.4%) in the VESPA arm (P <.0001).
At time 2, of the 6 bronchial segments evaluated (RB6, RB9, RB10, LB6, LB9, and LB10), a mean of 3.84±1.67 of those in the control group vs 1.21±1.63 of those in the VESPA group were considered atelectatic (P <.0001). At time 1, of the 6 bronchial segments assessed, a mean of 2.00±2.04 of those in the control arm and 0.76±1.42 of those in the VESPA arm were deemed atelectatic (P =.0031).
No major complications were reported in either group, with no significant differences detected between the groups regarding adverse events.
The current study has a number of limitations. The ventilation used in the control arm may not resemble the standard of care that is used at other institutions. Further, the evaluation for atelectasis at time 2 was approximately 45 to 50 minutes, and it is not known if VESPA can continue to prevent atelectasis beyond this point.
The investigators concluded that “VESPA significantly reduces the incidence of atelectasis, it is well tolerated, and has a sustained effect over time despite the bronchoscopic nodal staging.” Use of this strategy should be considered for patients who are undergoing bronchoscopy when atelectasis is to be avoided, they added.
Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.
Salahuddin M, Sarkiss M, Sagar AS, et al. “Ventilatory strategy to prevent atelectasis during bronchoscopy under general anesthesia: a multicenter randomized controlled trial” (VESPA Trial). Chest. Published online July 5, 2022. doi:10.1016/j.chest.2022.06.045