High Tidal Volume, High Positive End Expiratory Pressure and Apneic Breath Hold Strategies (Lung Navigation Ventilation Protocol) With Cone Beam Computed Tomography Bronchoscopic Biopsy of Peripheral Lung Lesions

Abstract

Background: A dedicated anesthesia protocol for bronchoscopic lung biopsy—lung navigation ventilation protocol (LNVP)—specifically designed to mitigate atelectasis and reduce unnecessary respiratory motion, has been recently described. LNVP demonstrated significantly reduced dependent ground glass, sublobar/lobar atelectasis, and atelectasis obscuring target lesions compared with conventional ventilation. Methods: In this retrospective, single-center study, we examine the impact of LNVP on 100 consecutive patients during peripheral lung lesion biopsy. We report the incidence of atelectasis using cone beam computed tomography imaging, observed ventilatory findings, anesthesia medications, and outcomes, including diagnostic yield, radiation exposure, and complications. Results: Atelectasis was observed in a minority of subjects: ground glass opacity atelectasis was seen in 30 patients by reader 1 (28%) and in 18 patients by reader 2 (17%), with good agreement between readers (κ = 0.78). Sublobar/lobar atelectasis was observed in 23 patients by reader 1 and 26 patients by reader 2, also demonstrating good agreement (κ = 0.67). Atelectasis obscured target lesions in very few cases: 0 patients (0%, reader 1) and 3 patients (3%, reader 2). Diagnostic yield was 85.9% based on the AQuIRE definition. Pathology demonstrated 57 of 106 lesions (54%) were malignant, 34 lesions (32%) were benign, and 15 lesions (14%) were nondiagnostic. Conclusion: Cone beam computed tomography images confirmed low rates of atelectasis, high tool-in-lesion confirmation rate, and high diagnostic yield. LNVP has a similar safety profile to conventional bronchoscopy. Most patients will require intravenous fluid and vasopressor support. Further study of LNVP and other ventilation protocols are necessary to understand the impact of ventilation protocols on bronchoscopic peripheral lung biopsy.

Severity of Atelectasis during Bronchoscopy: Descriptions of a New Grading System (Atelectasis Severity Scoring System—“ASSESS”) and At-Risk-Lung Zones

“…A few studies describing strategies to prevent atelectasis have been published to date [14,17,18]. While these studies reported a substantial decrease in the incidence of intra-bronchoscopy atelectasis with the respective ventilatory strategies, the severity of atelectasis was not reported in any of these studies.…”

“…A multicenter randomized controlled trial of standard fluoroscopy-guided bronchoscopy versus a thin bronchoscope with RP-EBUS conducted by Tanner and coworkers reported one of the greatest gaps between navigation (97%) and diagnostic yield (50%), which could be partly explained by atelectasis and false-positive images [13]. Thus, ventilatory and positional strategies have been proposed in order to prevent this unwanted phenomenon [14][15][16][17][18][19][20]. The VESPA trial (Ventilatory Strategy to Prevent Atelectasis) was a multicenter randomized controlled trial which compared standard ventilation through a laryngeal mask airway (LMA) with a 100% fraction of inspired oxygen (FiO 2 ) and a positive end-expiratory pressure (PEEP) of 0 cm H2O vs. VESPA, consisting of endotracheal intubation followed by a recruitment maneuver, FiO 2 titration (<100%), and a PEEP of 8-10 cm H 2 O [14].…”

Anesthetic considerations in interventional pulmonology

“…Although the original study did not report any incidence of increased complications, it is important to consider the possibility of barotrauma causing either pneumothorax or pneumomediastinum, and the hemodynamic instability caused by increasing pulmonary afterload using these ventilatory strategies. The authors recently published an update from 100 patients who had undergone peripheral bronchoscopy using the LNVP protocol [27 ▪▪ ]. In this follow up, while the incidence of atelectasis remained low, 67% patients required vasopressor support and majority of the patients received a large amount of intravenous fluid (average of 687 ± 198 ml crystalloid).…”

Selecting the Optimal Strategy to Prevent Atelectasis During Bronchoscopy

“…We read with great interest this new retrospective study by Bhadra et al 1 describing their experience with the use of lung navigation ventilation protocol (LNVP) to mitigate atelectasis during cone beam computed tomography–guided peripheral bronchoscopy. The authors utilized the lowest tolerable FiO 2 , high tidal volume (Vt; 10 to 12 mL/kg of ideal body weight), and high positive end-expiratory pressure (PEEP; 10 to 15 cm H 2 O for upper lobe lesions and 15 to 20 cm H 2 O for lower lobe lesions) as described in their prior chart review.…”

“…Although virtually all patients sustained hemodynamic instability in the current report of LNVP, the authors conclude that their strategy has a similar safety profile compared with conventional guided bronchoscopy. Hemodynamic instability was not reported as a complication of the procedure in this study; rather, the use of vasopressors and fluids was simply listed in Table 3 1 with other drugs utilized to achieve anesthesia. It is well known that hemodynamic instability can be deleterious and life-threatening, particularly in patients with coronary artery disease and pulmonary hypertension, resulting in cardiac ischemia, arrhythmias, and potentially death, and it should be avoided when possible.…”