The use of transbronchial cryobiopsy for diffuse parenchymal lung disease in critically ill patients with acute hypoxemic respiratory failure-A case series.

OBJECTIVES: Accurate diagnosis and management of undifferentiated diffuse parenchymal lung disease (DPLD) in critically ill patients is challenging. Transbronchial forceps biopsies have limited utility and surgical lung biopsies can be detrimental for critically ill patients. Transbronchial cryobiopsy (TBC) has shown increased diagnostic yield compared to conventional forceps biopsy in DPLD. However, TBC has not been studied in intensive care unit (ICU) patients. In this case series, we describe our experience with TBC for diagnosis of DPLD in ICU patients with acute hypoxemic respiratory failure. METHODS: This case series includes critically ill patients who underwent TBC at two different tertiary care hospitals. Procedures were performed by the same interventional pulmonologist using the two therapeutic bronchoscopes with a 2.8-mm working channel, and a 1.9- or 2.4-mm cryoprobe. RESULTS: We performed TBC in 17 patients of which 12 (70.1%) were performed at bedside in ICU without fluoroscopic guidance. Pathological diagnosis was made in 15 (88%) patients which resulted in changes in management in most of these patients. Six patients (35.3%) developed pneumothorax post-procedure with 5 (29.4%) requiring a chest tube. Moderate bleeding was noted in one (6%) patient and no severe or fatal bleeding occurred. Our 30-day ICU mortality was 47% (n = 8); however, no deaths were directly attributable to the procedure. CONCLUSIONS: TBC is a feasible technique with an acceptable complication rate and a fairly high histopathological yield in ICU patients with DPLD and acute hypoxemic respiratory failure. Appropriate diagnosis can be crucial in making management decisions for these patients.

Safety of performing transbronchial lung cryobiopsy on hospitalized patients with interstitial lung disease.

INTRODUCTION: Transbronchial lung cryobiopsy (TBLC) has become a popular option for tissue diagnosis of interstitial lung disease (ILD), however reports vary regarding the safety of this procedure. Herein, we evaluate the safety of transbronchial cryobiopsy in hospitalized patients, comparing adverse events to outpatient procedures. METHODS AND MEASUREMENTS: This is a single center, retrospective chart review of all TBLC performed for suspected ILD between November 2013 and March 2017. Biopsies were performed by a board certified interventional pulmonologist or interventional pulmonology fellow using a two-scope technique. RESULTS: One hundred fifty-nine cryobiopsies were performed for the diagnosis of ILD. Rates of adverse events are as follows: pneumothorax 11%, persistent air leak 1.3%, moderate-severe bleeding 3.8%, ICU transfer within 48 h 3.1%, and all cause 30-day mortality 1.9%. No deaths were attributed to the procedure. Comparing adverse events between hospitalized patients and outpatients, rates of pneumothorax were 24% vs 9.9%, persistent air leak 5.9% vs 0.7%, ICU transfer 12% vs 2.1%, and 30-day mortality 5.9% vs 1.4%. However, no differences were statistically significant. CONCLUSION: Practitioners should recognize that while cryobiopsies are a high-yield, safe, and cost-effective alternative to surgical lung biopsy, not all procedures carry the same risk profiles. Hospitalized patients may have a greater propensity for pneumothorax, persistent air leak, transfer to the ICU, and 30-day mortality.

Can a transient exertion-related carotid (TERC) murmur heard during a symptom-limited exercise test be used as a means for managing sports concussion?

We hypothesize that a transient exertion-related carotid (TERC) murmur flow murmur similar in nature to a "bruit" heard best at the carotid artery during exercise in healthy individuals can be used as a means for assessing post-concussion injury exertion tolerance. Typically there are no arterial sounds heard at the carotid artery in healthy individuals. Bruit, heard at rest, is an indicator of cardiovascular disease. Listening for a flow murmur or bruit-like sounds during exercise may indicate brain blood flow autoregulation and that this audible change in brain blood flow autoregulation could be used to assess exercise tolerance. We present very preliminary evidence supporting our hypothesis in that a transient exertion-related carotid (TERC) murmur is heard at a HR (HR) of approximately 150 beats per minute (bpm) in healthy individuals and 120bpm in concussion patients. Future prospective clinical studies to validate this hypothesis and these methods may aid clinicians who manage concussion patients by using this method to help guide exertion protocols.

Ultrasound-enhanced rt-PA thrombolysis in an ex vivo porcine carotid artery model.

Ultrasound is known to enhance recombinant tissue plasminogen activator (rt-PA) thrombolysis. In this study, occlusive porcine whole blood clots were placed in flowing plasma within living porcine carotid arteries. Ultrasonically induced stable cavitation was investigated as an adjuvant to rt-PA thrombolysis. Aged, retracted clots were exposed to plasma alone, plasma containing rt-PA (7.1 ± 3.8 µg/mL) or plasma with rt-PA and Definity® ultrasound contrast agent (0.79 ± 0.47 µL/mL) with and without 120-kHz continuous wave ultrasound at a peak-to-peak pressure amplitude of 0.44 MPa. An insonation scheme was formulated to promote and maximize stable cavitation activity by incorporating ultrasound quiescent periods that allowed for the inflow of Definity®-rich plasma. Cavitation was measured with a passive acoustic detector throughout thrombolytic treatment. Thrombolytic efficacy was measured by comparing clot mass before and after treatment. Average mass loss for clots exposed to rt-PA and Definity® without ultrasound (n = 7) was 34%, and with ultrasound (n = 6) was 83%, which constituted a significant difference (p < 0.0001). Without Definity® there was no thrombolytic enhancement by ultrasound exposure alone at this pressure amplitude (n = 5, p < 0.0001). In the low-oxygen environment of the ischemic artery, significant loss of endothelium occurred but no correlation was observed between arterial tissue damage and treatment type. Acoustic stable cavitation nucleated by an infusion of Definity® enhances rt-PA thrombolysis without apparent treatment-related damage in this ex vivo porcine carotid artery model.