Inadequate Lung Isolation in Association with Asymmetric Inflation of an Arndt™ Bronchial Blocker

Abstract

To the Editor In a 64-year-old man undergoing esophagogastrectomy via a combined midline abdominal incision and subsequent right thoracotomy, a 9.0F, 78-cm Arndt™ wire-guided elliptical bronchial blocker (Cook® Medical, Bloomington, IN) was placed through an 8.0-mm endotracheal tube into the right main stem bronchus under direct vision. After inflating the cuff with 5 mL of air, and after thoracotomy, we noted persistence of right lung ventilation. Position of the blocker was reconfirmed with bronchoscopy, and an additional 2 mL of air (total of 7 mL) did not change the surgical conditions. The Arndt bronchial blocker was removed and replaced with a 39F left-sided double lumen endotracheal tube, and adequate lung isolation was achieved. Examination of the Arndt blocker demonstrated that with up to 4 mL of air, the blocker had symmetric inflation (Fig. 1), and indeed the resident checked the blocker with this amount of air before the start of the case. However, beyond this, there was asymmetric inflation that became more pronounced as more air was added. There was also a concavity in the shape of the blocker, with 1 surface almost adherent to the lumen (Fig. 2). Inflation of the blocker within the barrel of a 10-mL clear plastic syringe showed no obvious lack of coaptation of the balloon with the syringe surface, but the yellow lumen was extremely off-center (Fig. 3).Figure 1: Arndt™ bronchial blocker inflated with 4 mL of air. Notice the apparent symmetric inflation.Figure 2: Same bronchial blocker as in Figure 1 with 7 mL of air. Notice the extreme asymmetry of inflation as well as the concavity of the surface facing upward.Figure 3: Same blocker as previous figures, inflated in the barrel of a clear plastic 10-mL syringe. Notice that the yellow lumen is off-center.Arndt blockers are known to be more susceptible to malpositioning after initial placement than other types of blockers or double-lumen tubes,1 but fiberoptic bronchoscopy was used multiple times to confirm correct placement. We typically use 5 to 8 mL of air to achieve lung isolation with the Arndt 9.0F elliptical blocker, which is consistent with the literature.2 The brochure that accompanies the device describes “average inflation volumes” as between 6 and 12 mL. The authors have in the past (and subsequently) observed Arndt blockers with symmetric inflation from different lots and have achieved adequate lung isolation with these devices. We suggest that the inflation pattern and resultant concavity contributed to the clinical situation described and that clinicians should consider checking Arndt blockers for asymmetric inflation using at least 6 mL of air before placement. Brian P. Barrick, MD, DDS Mary W. Brandon, DO David A. Zvara, MD Department of Anesthesiology University of North Carolina Hospital Chapel Hill, North Carolina [email protected]