Stultz, Benjamin R.

Abstract Rationale Oscillometry measures the mechanical properties of the respiratory system using the response to pressure signals superimposed on tidal breathing. The JaegerTM IOS device generates “pulse packets” of harmonic frequencies between 5 and 35 Hz in 5 Hz intervals, while the Resmon ProTM V3 FOT and Thorasys TremofloTM C-100 employ prime pseudorandom sine waveforms between 5-19 Hz and 5-37 Hz, respectively. Prior studies have raised concerns about harmonic distortion with the IOS technique, but a direct comparison of reproducibility using current devices has not been performed. Methods Healthy volunteers with normal spirometry performed weekly oscillometry following ERS technical standards using JaegerTM and ResmonTM or ThorasysTM oscillometers in random order for 10 consecutive weeks. Z scores were calculated using Berger and Oostveen normative equations. Means, pooled within-subject distributions and interquartile range, standard error (SEM), coefficient of variation (CVw%), absolute and relative minimal detectable change (MDC, MDC%), and between device and subject intraclass correlation coefficients (ICC) were calculated for R5, R10/R11, R20/R19, R5-R20/R5-R19, X5, AX, and Fres and compared. Results Fifteen participants completed 10 weekly measurement sessions with JaegerTM and ResmonTM and twelve with JaegerTM and ThorasysTM. One subject did not complete the ResmonTM analysis due to intolerance; another subject only completed three weeks of ThorasysTM prior to work assignment change. The majority (65%) were female with mean (SD) age of 37.7 (10.2) years and BMI 27 (5) kg/m2. Rrs reproducibility was excellent across devices (ICC > 0.89), with more variability for X5, AX, and Fres (ICC 0.66 - 0.93) and little difference between devices (Figure 1). Small, systematic increases in mean Rrs were seen with JaegerTM compared to ResmonTM (5-10%, p < 0.008) and TremofloTM (5-12%, p < 0.02), with higher mean AX vs ResmonTM (44%, p = 0.002) and lower Fres vs TremofloTM (19%, p = 0.02). There was high ICC (0.97-0.99) across ResmonTM and TremofloTM Rrs comparisons with minimal bias. Intra-subject reproducibility was similar between devices. MDC% was 22.7-39.4% for Rrs values, 52.7-70.8% for X5, and 131-142% for AX. Conclusions JaegerTM, ResmonTM, and ThorasysTM oscillometers performed similarly in healthy adults over 10 weeks, with small but systematic measurement differences seen with the JaegerTM device. Rrs and Fres values demonstrated the greatest reproducibility both within and between subjects. Reactance measurements had less between-device agreement and higher MDC. Rrs, X5, and AX changes of up to 40%, 70%, and 140% over time may be due to normal subject and measurement variation. This abstract is funded by: 2024 Pulmonary, Critical Care, and Sleep Medicine Schuen Family Innovation Award

Abstract Introduction Solid tumors modify local angiogenesis and co-opt surrounding vasculature to maintain energy supply required for ongoing growth. This process is often complicated by metastasis and hemorrhage. Pulmonary tumors can rarely create intrapulmonary shunt physiology and hypoxemia in this manner; this has been described most often in bronchoalveolar carcinoma. We present a case of malignant intrapulmonary shunt occurring with spindle cell sarcoma, which resolved with arterial embolization. Case Presentation A 72-year-old male with a history of stage IV spindle cell sarcoma with abdominal, vertebral, and pulmonary metastases presented to an outpatient appointment with three weeks of fatigue and decreased exercise tolerance. He had no history of parenchymal lung disease nor any home oxygen requirement. In clinic, he was found to require 6L per minute of supplemental oxygen to maintain saturation of 88%. He was directly admitted to the oncology service. Initial laboratory evaluation was unremarkable. CT imaging demonstrated normal lung parenchyma, no pulmonary embolism, and an 11cm vascular tumor involving proximal branches of the local pulmonary artery (Figure). Transthoracic echocardiography (TTE) with agitated saline revealed a large intrapulmonary shunt. As the patient had limited response to oxygen therapy, this intra-tumoral shunt was deemed the most likely cause of his hypoxemia. Surgical resection was considered but was deemed to confer limited clinical benefit in the setting of multiple metastases. Embolization of the local pulmonary artery was therefore pursued with Interventional Radiology. The patient tolerated the procedure well with complete resolution of hypoxemia post-procedure. His energy and mobility improved, and he was discharged home. Three months later, he continued to require no supplemental oxygen. Discussion While shunt physiology is commonly part of the differential for hypoxemia, it is rarely described as an oncologic complication. This appears to be the first report of such pathology in a sarcoma patient, and the first to report shunt resolution through arterial embolization rather than surgical resection or systemic anti-tumor therapy. In addition, previous cases typically describe shunt detection via selective pulmonary arterial occlusion by Swan-Ganz catheter, whereas here the noninvasive TTE with agitated saline was sufficient. While the few existing reports highlight good response to lobectomy or pneumonectomy, this case highlights the potential for minimally invasive vascular intervention. Despite the metastatic nature of this patient’s disease, he received significant, rapid physiologic and functional benefit from a procedure with less morbidity. Maintaining suspicion of intra-tumoral shunt physiology is appropriate for patients with vascular pulmonary masses and hypoxemia. This abstract is funded by: None

ABSTRACT The combination of cirrhosis and chronic pancreatitis is rare and poses increased risk of hemorrhage requiring close clinical monitoring. We present a patient with history of alcohol-associated cirrhosis and chronic pancreatitis who was admitted to the intensive care unit with clinical hemorrhage believed secondary to epistaxis. After initial delay, esophagogastroduodenoscopy ultimately found blood and clots evacuating through the ampulla consistent with hemosuccus pancreaticus confirmed with computed tomography angiography. The patient ultimately improved with coil and gel foam vascular embolization. This case highlights the dangers of early diagnostic closure and presents a rare finding of hemosuccus without pseudoaneurysm formation.