Protocolized Thoracic Ultrasonography in Transbronchial Lung Cryobiopsies: A Potential Role as an Exclusion Study for Pneumothorax

Pneumothorax detection with thoracic ultrasound as the method of choice in interventional pulmonology - A retrospective single-center analysis and experience

BACKGROUND

Recent studies have shown that thoracic ultrasound (TUS) is not inferior to chest radiography (CR) in detecting pneumothorax (PTX). It is unclear if adopting TUS can reduce the number of CR in the daily clinical routine. This retrospective study investigates the utilization of post-interventional CR and TUS for PTX detection after the introduction of TUS as the method of choice in an interventional pulmonology unit.

METHODS

All interventions with CR or TUS for ruling out PTX performed in the Pneumology Department of the University Hospital Halle (Germany) 2014 to 2020 were included. The documented TUS and CR performed before (period A) and after the introduction of TUS as the method of choice (period B), as well as the number of diagnosed and missed PTX were recorded.

RESULTS

The study included 754 interventions (110 in period A and 644 in period B). The proportion of CR decreased from 98.2% (n = 108) to 25.8% (n = 166) (p < 0.001). During period B, a total of 29 (4.5%) PTX were diagnosed. Of these, 28 (96.6%) were detected on initial imaging (14 by CR, 14 by TUS ). One PTX (0.2%) was initially missed by TUS, none by CR. Confirmatory investigations were ordered more frequently after TUS (21 of 478, 4.4%) than after CR (3 of 166, 1.8%).

CONCLUSION

The use of TUS in interventional pulmonology can effectively reduce the number of CR and thus save resources. However, CR may still be favored in specific circumstances or if pre-existing conditions limit sonographic findings.

Transbronchial cryobiopsy in unexplained, severe ARDS: a single center retrospective case series

BACKGROUND

Acute respiratory distress syndrome (ARDS) deptics an acute form of lung infjury with often severe respiratory impairment that requires invasive mechanical ventilation. Since ARDS can be caused by several distinct etiologies, correct characterization is desired and frequently challenging. Surgical lung biopsy was previously reported to be of additive value. We describe our institutional experience using transbronchial cryobiopsy (TBCB) for further characterization of severe and unexplained ARDS cases.

CASE PRESENTATION

We retrospectively collected data of TBCB in patients with unexplained ARDS, whether with or without ECMO-support. Between 2019 and 2020 TBCB was performed in eight patients. Decision for the intervention was decided in multidisciplinary discussion. Five patients were treated with ECMO. The median duration of invasive ventilation before TBCB was 24 days. TBCB was performed in one segment, that was prophylactically occluded by Watanabe spigot or swab after the procedure. Histology results and their contribution to further therapeutic decisions were analyzed. Histology revealed five diffuses alveolar damage, one acute fibrinoid organizing pneumonia, one cryptogenic organizing pneumonia and one lung cancer. All results contributed to the decision of further management. While no pneumothorax or severe endobronchial bleeding occurred, two delayed hematothoraces needed surgical treatment. No patients died due to TBCB.

CONCLUSION

TBCB is feasible in ARDS even during ECMO treatment. Histologic results can play a significant role in therapeutic and ethic discussion to guide the patients' care. Side effects should be considered and monitored.

Safety and Efficacy of Manual Aspiration Via Small Bore Chest Tube in Facilitating the Outpatient Management of Transbronchial Biopsy-related Iatrogenic Pneumothorax

BACKGROUND

Iatrogenic pneumothorax complicates transbronchial biopsies with a prevalence of 1% to 6%. Conventional treatment consists of inpatient management with chest tube drainage. While aspiration techniques have been investigated in the management of both primary spontaneous and transthoracic lung biopsy-induced pneumothorax, its role in the management of transbronchial biopsy-iatrogenic pneumothorax (TBBX-IP) is undefined. An appealing treatment alternative for TBBX-IP may exist in the placement of a small bore chest tube (SBCT) followed by a manual aspiration (MA) technique promoting earlier SBCT removal to facilitate outpatient management. To our knowledge, no study exists evaluating the efficacy of MA via a SBCT performed specifically for TBBX-IP.

PATIENTS AND METHODS

Prospective evaluation of the efficacy of a protocolized pathway incorporating MA through a SBCT for the outpatient management of TBBX-IP. Primary outcome was the clinicoradiographic resolution of TBBX-IP avoiding hospitalizations.

RESULTS

A total of 763 biopsies performed; 31 complicated by TBBX-IP, 18 qualified for intervention. Sixteen were outpatients, 2 inpatients. Thirteen (81.25%) of the 16 outpatients were successfully treated with MA via SBCT and did not require admission. Twelve (75%) of these 13 had SBCT removed, 1 patient was discharged with SBCT and removed in 24 hours. Of the 18 patients requiring intervention, 13 (72.2%) were successfully treated with MA via SBCT enabling removal of SBCT. No patient required reintervention.

CONCLUSION

MA via SBCT represents a safe and viable management approach of TBBX-IP promoting earlier SBCT removal and decreased hospitalizations. Our results challenge conventional management of TBBX-IP warranting further investigation.

Lung ultrasound assessment for pneumothorax following transbronchial lung cryobiopsy

Background

Iatrogenic pneumothorax is a common and clinically important transbronchial cryobiopsy (TBCB) complication. A study was conducted to assess the diagnostic accuracy and clinical impact of immediate post-procedure lung ultrasound for diagnosing iatrogenic pneumothorax in patients suspected of interstitial lung disease (ILD) undergoing TBCB.

Study design and methods

In patients undergoing TBCB due to suspected ILD, lung ultrasound of the anterior surface of the chest was performed immediately after the TBCB procedure prior to extubation. Presence of lung point was used as a definite sign of pneumothorax. Chest radiography was routinely performed 2 h after TBCB and was used as the reference standard.

Results

A total of 141 consecutive patients were included. Post-procedure lung ultrasound identified definite pneumothorax in five patients (3.6%, 95% confidence interval (CI) 1.5–8.3%). Chest radiography at 2 h identified 19 patients (13.5%, 95% CI 8.7–20.2%) with pneumothorax following TBCB. The diagnostic accuracy of lung ultrasound for diagnosing pneumothorax was as follows: sensitivity: 21.1% (95% CI 6.1–45.6%), specificity: 99.2% (95% CI 95.5–100.0%), positive predictive value (PPV): 80.0% (95% CI 28.4–99.5%) and negative predictive value (NPV): 89.0% (95% CI 82.5–93.7%). Post-procedure lung ultrasound had a clinical impact in five patients (3.6%, 95% CI 1.5–8.3), of which four had a pleural drain inserted prior to extubation and one underwent prolonged observation prior to extubation.

Interpretation

Lung ultrasound performed immediately following TBCB has a clinical impact by identifying patients with pneumothorax in need of immediate treatment prior to extubation and by monitoring pneumothorax size in the operating room. Supplementary imaging prior to patient discharge is still needed however, as the majority of pneumothoraxes develop later in the post-procedure period.

Lung ultrasound immediately following transbronchial lung cryobiopsy can identify early pneumothorax development. Supplementary imaging is, however, still needed since most pneumothoraxes develop later in the post-procedure period.https://bit.ly/3ubcDLh

Recommendations for Lung Ultrasound in Internal Medicine

A growing amount of evidence prompts us to update the first version of recommendations for lung ultrasound in internal medicine (POLLUS-IM) that was published in 2018. The recommendations were established in several stages, consisting of: literature review, assessment of literature data quality (with the application of QUADAS, QUADAS-2 and GRADE criteria) and expert evaluation carried out consistently with the modified Delphi method (three rounds of on-line discussions, followed by a secret ballot by the panel of experts after each completed discussion). Publications to be analyzed were selected from the following databases: Pubmed, Medline, OVID, and Embase. New reports published as of October 2019 were added to the existing POLLUS-IM database used for the original publication of 2018. Altogether, 528 publications were systematically reviewed, including 253 new reports published between September 2017 and October 2019. The new recommendations concern the following conditions and issues: pneumonia, heart failure, monitoring dialyzed patients' hydration status, assessment of pleural effusion, pulmonary embolism and diaphragm function assessment. POLLUS-IM 2020 recommendations were established primarily for clinicians who utilize lung ultrasound in their everyday clinical work.

Thoracic Ultrasound for Immediate Exclusion of Pneumothorax after Interventional Bronchoscopy

Background. Pneumothorax is a common side effect in interventional pulmonology. The ideal moment for detection with chest X-ray or ultrasound has not yet been defined. Earlier studies demonstrated the utility of performing these tests with a certain delay, which always results in a potentially dangerous gap. Methods. We prospectively enrolled patients with pulmonary interventions at increased risk of pneumothorax. Thoracic ultrasound was performed immediately after the intervention and at the moment of chest X-ray with a delay up to two hours. Results: Overall, we detected four pneumothoraxes in 115 procedures. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 75%, 100%, 100%, 99%, 99% for ultrasound and 75%, 90%, 21%, 99% und 89% for chest X-ray respectively. All pneumothoraces requiring chest tube were sufficiently detected by both methods. Conclusion. Thoracic ultrasound when performed immediately can more accurately exclude pneumothorax after interventional bronchoscopy when compared to chest X-ray. Further ultrasound examinations are unnecessary.