A prospective observation study of the dynamic monitoring of transcutaneous arterial blood oxygen saturation and carbon dioxide during bronchoscopy.

BACKGROUND AND AIMS: Because bronchoscopy is an invasive procedure, sedatives and analgesics are commonly administered, which may suppress the patient's spontaneous breathing and can lead to hypoventilation and hypoxemia. Few reports exist on the dynamic monitoring of oxygenation and ventilation during bronchoscopy. This study aimed to prospectively monitor and evaluate oxygenation and ventilation during bronchoscopy using transcutaneous arterial blood oxygen saturation and carbon dioxide. METHODS: We included patients who required pathological diagnosis using fluoroscopic bronchoscopy at our hospital between March 2021 and April 2022. Midazolam was intravenously administered to all patients as a sedative during bronchoscopy, and fentanyl was administered in addition to midazolam when necessary. A transcutaneous blood gas monitor was used to measure dynamic changes, including arterial blood partial pressure of carbon dioxide (tcPCO2), transcutaneous arterial blood oxygen saturation (SpO2), pulse rate, and perfusion index during bronchoscopy. Quantitative data of tcPCO2 and SpO2 were presented as mean ± standard deviation (SD) (min-max), while the quantitative data of midazolam plus fentanyl and midazolam alone were compared. Similarly, data on sex, smoking history, and body mass index were compared. Subgroup comparisons of the difference (Δ value) between baseline tcPCO2 at the beginning of bronchoscopy and the maximum value of tcPCO2 during the examination were performed. RESULTS: Of the 117 included cases, consecutive measurements were performed in 113 cases, with a success rate of 96.6%. Transbronchial lung biopsy was performed in 100 cases, whereas transbronchial lung cryobiopsy was performed in 17 cases. Midazolam and fentanyl were used as anesthetics during bronchoscopy in 46 cases, whereas midazolam alone was used in 67 cases. The median Δ value in the midazolam plus fentanyl and midazolam alone groups was 8.10 and 4.00 mmHg, respectively, indicating a significant difference of p < 0.005. The mean ± standard deviation of tcPCO2 in the midazolam plus fentanyl and midazolam alone groups was 44.8 ± 7.83 and 40.6 ± 4.10 mmHg, respectively. The SpO2 in the midazolam plus fentanyl and midazolam alone groups was 94.4 ± 3.37 and 96.2 ± 2.61%, respectively, with a larger SD and greater variability in the midazolam plus fentanyl group. CONCLUSION: A transcutaneous blood gas monitor is non-invasive and can easily measure the dynamic transition of CO2. Furthermore, tcPCO2 can be used to evaluate the ventilatory status during bronchoscopy easily. A transcutaneous blood gas monitor may be useful to observe regarding respiratory depression during bronchoscopy, particularly when analgesics are used.

90-Day outcomes in patients with severe COVID-19 pneumonia treated with invasive mechanical ventilation.

BACKGROUND: There are few reports detailing the prognostic factors of severe COVID-19 pneumonia requiring invasive ventilation. We investigated the long-term prognosis and evaluated which factors influenced outcomes in these patients. METHODS: Data was reviewed from severe adult COVID-19 cases admitted to our hospital and treated with mechanical ventilation between February 1, 2020, and October 30, 2021. On admission to our hospital, comorbidities and laboratory findings were collected from clinical records. Prognostic information for 90 days after diagnosis was also obtained from hospitals where patients were transferred after their conditions stabilized. RESULTS: Prognostic information was obtained in 133 patients, of which 106 were males (79.7 %). Of the 133 patients, 67 were discharged (51.5 %), 21 continued inpatient care (15.8 %), and 45 died (33.8 %). Age, Charlson Risk Index, and the number of patients on hemodialysis were significantly higher in the deceased group. There were no differences in therapeutic interventions between survivors and those who died except for a higher rate of muscle relaxant and vasopressor usage in the deceased group. Laboratory findings on admission showed significantly higher levels of BUN, creatinine, and serum Krebs von den Lungen 6 (KL-6), and significantly lower platelet counts, hemoglobin, and alanine aminotransferase in those who died. Multivariate analysis revealed that age, hemodialysis, lower platelet counts, and higher KL-6 were independent predictors for 90-day mortality. CONCLUSIONS: Older age, hemodialysis, lower platelet counts and high KL-6 on admission were identified as independent predictors of 90-day mortality in patients with respiratory failure due to severe COVID-19 under invasive mechanical ventilation.

A Quantitative Computed Tomography Analysis of Fissure Integrity and Emphysema Destruction in Japanese Patients with Severe Chronic Obstructive Pulmonary Disease.

Objective Bronchoscopic lung volume reduction (BLVR) using a one-way endobronchial valve (EBV) can provide clinically meaningful benefits to chronic obstructive pulmonary disease (COPD) patients. Although the Japanese Pharmaceuticals and Medical Devices Agency approved EBVs in November 2022, information regarding the number of Japanese patients with severe COPD eligible for BLVR treatment is still lacking. We therefore screened computed tomography (CT) images of patients with severe COPD using a quantitative CT (QCT) analysis to estimate the proportion of candidates eligible for BLVR treatment with an EBV. Methods CT scans of COPD patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 3 and 4 were retrospectively analyzed using QCT to evaluate fissure integrity and tissue destruction. The difference in volume-weighted percentage was measured using the density scores of the target lobe and ipsilateral non-target lobe at -910 Hounsfield units. The target lobe was defined as the most affected lobe, with an emphysema destruction score of >50% for each patient. Results High-resolution CT scans of 32 patients (GOLD 3=19, GOLD 4=13) were analyzed. The target lobe could not be identified in 1 patient, whereas the target lobes for 8 patients were not surrounded by fissures with ≥80% completeness. Conversely, in 13 patients, the target lobes were surrounded by fissures with >95% completeness. The remaining 10 patients had fissure completeness between 80% and 95% at the target lobes and were considered candidates for collateral ventilation assessment. Conclusion A QCT analysis showed that 23 of 32 patients with severe COPD could be considered for a thorough examination of BLVR treatment with EBV.

High efficacy of brigatinib for brain metastases in ALK fusion gene-positive non-small cell lung cancer: A case series.

Anaplastic lymphoma kinase (ALK) fusion gene-positive lung cancer often shows brain metastasis at initial diagnosis or during the course of treatment. However, molecular-targeted drugs are known to pass through the blood-brain barrier and present positive effects for central nervous system lesions. There are few reports suggesting how effective molecular-targeted drug therapy alone is for brain metastasis lesions of ALK fusion-positive lung cancer, especially after the first use of ALK-tyrosine kinase inhibitor (TKI) or for bulky brain metastases. A patient in his mid-fifties with stage IV pleural dissemination developed brain metastases after 10 years of crizotinib use, but showed a complete response after switching to brigatinib. Moreover, a patient in her early sixties with stage III recurrent large brain metastases 5 years after chemoradiation therapy experienced dramatic tumor shrinkage with brigatinib. In each case of ALK fusion gene-positive lung cancer with brain metastases, brigatinib showed a high efficacy and was well-tolerated after previous ALK-TKI and for bulky lesions.

Predicting the aggravation of coronavirus disease-19 pneumonia using chest computed tomography scans.

Presently, coronavirus disease-19 (COVID-19) is spreading worldwide without an effective treatment method. For COVID-19, which is often asymptomatic, it is essential to adopt a method that does not cause aggravation, as well as a method to prevent infection. Whether aggravation can be predicted by analyzing the extent of lung damage on chest computed tomography (CT) scans was examined. The extent of lung damage on pre-intubation chest CT scans of 277 patients with COVID-19 was assessed. It was observed that aggravation occurred when the CT scan showed extensive damage associated with ground-glass opacification and/or consolidation (p < 0.0001). The extent of lung damage was similar across the upper, middle, and lower fields. Furthermore, upon comparing the extent of lung damage based on the number of days after onset, a significant difference was found between the severe pneumonia group (SPG) with intubation or those who died and non-severe pneumonia group (NSPG) ≥3 days after onset, with aggravation observed when ≥14.5% of the lungs exhibited damage at 3-5 days (sensitivity: 88.2%, specificity: 72.4%) and when ≥20.1% of the lungs exhibited damage at 6-8 days (sensitivity: 88.2%, specificity: 69.4%). Patients with aggravation suddenly developed hypoxemia after 7 days from the onset; however, chest CT scans obtained in the paucisymptomatic phase without hypoxemia indicated that subsequent aggravation could be predicted based on the degree of lung damage. Furthermore, in subjects aged ≥65 years, a significant difference between the SPG and NSPG was observed in the extent of lung damage early beginning from 3 days after onset, and it was found that the degree of lung damage could serve as a predictor of aggravation. Therefore, to predict and improve prognosis through rapid and appropriate management, evaluating patients with factors indicating poor prognosis using chest CT is essential.

Home High-Flow Nasal Cannula Oxygen Therapy for Stable Hypercapnic COPD: A Randomized Clinical Trial.

Rationale: The long-term effects of using a high-flow nasal cannula for chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease remain unclear. Objectives: To assess whether long-term high-flow nasal cannula use reduces the number of exacerbations and improves other physiological parameters in patients with chronic hypercapnic respiratory failure caused by chronic obstructive pulmonary disease. Methods: We enrolled 104 participants (aged ⩾40 yr) with daytime hypercapnia (Global Initiative for Chronic Obstructive Lung Disease stages 2-4) receiving long-term oxygen therapy (⩾16 h/d for ⩾1 mo) and randomly assigned them to high-flow nasal cannula/long-term oxygen therapy and long-term oxygen therapy groups. The primary endpoint was the moderate or severe exacerbation rate. We compared changes from baseline in arterial blood gas values, peripheral oxygen saturation, pulmonary function, health-related quality-of-life scores, and the 6-minute-walk test. Measurements and Main Results: High-flow nasal cannula use significantly reduced the rate of moderate/severe exacerbations (unadjusted mean count 1.0 vs. 2.5, a ratio of the adjusted mean count between groups [95% confidence interval] of 2.85 [1.48-5.47]) and prolonged the duration without moderate or severe exacerbations. The median time to first moderate or severe exacerbation in the long-term oxygen therapy group was 25 (14.1-47.4) weeks; this was not reached in the high-flow nasal cannula/long-term oxygen therapy group. High-flow nasal cannula use significantly improved health-related quality of life scores, peripheral oxygen saturation, and specific pulmonary function parameters. No safety concerns were identified. Conclusions: A high-flow nasal cannula is a reasonable therapeutic option for patients with stable hypercapnic chronic obstructive pulmonary disease and a history of exacerbations. Clinical trial registered with www.umin/ac.jp (UMIN000028581) and www.clinicaltrials.gov (NCT03282019).

Flexible bronchoscopy for lung cancer diagnosis in patients aged ≥85 years.

AIM: Flexible bronchoscopy (FB) is a common modality for the diagnosis of lung cancer. Recently, the number of older patients with lung cancer is increasing, and FB is being utilized more for these patients. METHODS: FB carried out in patients aged ≥85 years at St. Marianna University Hospital, Kawasaki, Japan, were reviewed. The indication of FB was decided on a case-by-case basis, taking into consideration the condition of the patient, which included mental status and accessibility of the lesion. Outcomes included complications, diagnostic yields, treatment options and survival after FB evaluation. RESULTS: From April 2015 to March 2019, 1604 diagnostic FBs were carried out. A total of 28 were carried out for the diagnosis of lung cancer (19 transbronchial lung biopsy, 9 transbronchial needle aspiration) in patients aged ≥85 years. Although there were three complications reported (pneumonia, fever, asthma exacerbation), they were successfully treated. A total of 19 cases were diagnosed with malignancy; five were treated with stereotactic body radiation therapy, five were prescribed targeted therapy, two underwent surgery and one was treated by cytotoxic monotherapy. Six patients were not included for active treatment. A total of 12 patients who received active treatment for lung cancer reported a 2-year survival rate of >60%. CONCLUSIONS: FB for lung cancer diagnosis in patients aged ≥85 years were carried out with acceptable safety and diagnostic yield. Considering the development of less invasive therapeutic measures for lung cancer, FB is safe and valuable in individuals aged ≥85 years suspected of lung cancer with therapeutic indications. Geriatr Gerontol Int 2022; 22: 32-35.

A case of advanced adenocarcinoma genetically confirmed with EGFR/BRAF co-mutation in both primary and metastatic lesions.

Driver mutations in lung cancer have been generally considered mutually exclusive; however, multiple gene screenings have recently become mainstream. Therefore, it is not uncommon to identify two or more mutations at first diagnosis, making it difficult to determine which tyrosine kinase inhibitor to administer. A 69-year-old woman complaining of back pain was diagnosed with adenocarcinoma T4N3M1c, stage IVB. Although PCR mutation test detected exon21 L858R point mutation by bronchoscopic sample, the therapeutic effect of afatinib was poor. Subsequently, next-generation sequencing (NGS) panel test of a metastasized bone specimen confirmed BRAF V600E. Furthermore, high sensitivity NGS panel system found the gene mutation allele frequency was higher for BRAF V600E than EGFR exon21 L858R for both primary lung tissue and the metastasized specimen. Subsequent BRAF/MEK inhibitor administration showed a remarkable treatment effect. When two or more driver mutations are detected in lung cancer, confirming the allelic frequency of the mutant gene might be useful in selecting more effective agents for front-line treatment.

Assessment of Extensive Airway Obstruction Using Point-by-Point Lateral Pressure Measurements during Bronchoscopy.

BACKGROUND: The positioning of the stent at the flow-limiting segment is crucial for patients with extensive airway obstruction to relieve dyspnea. However, CT and flow-volume curves cannot detect the area of maximal obstruction. OBJECTIVES: The aim of this study is to physiologically evaluate extensive airway obstruction during interventional bronchoscopy. METHODS: We prospectively measured point-by-point lateral airway pressure (Plat) at multiple points from the lower lobe bronchus to the upper trachea using a double-lumen catheter in 5 patients. The site of maximal obstruction was evaluated continuously to measure point-by-point Plat at multiple points when the airway catheter was withdrawn from the lower lobe bronchus to the upper trachea. RESULTS: Remarkable pressure differences occurred at the site of maximal obstruction assessed by point-by-point Plat measurements. After initial stenting in 1 case, migration of the maximal obstruction to a nonstented segment of the weakened airway was seen with extensive stenosis from the trachea to the bronchi. In the second case, in addition to radiological analysis, point-by-point Plat measurements could identify the location of the maximal obstruction which contributed to dyspnea. CONCLUSIONS: Point-by-point Plat measurement could be used to detect the site of maximal obstruction physiologically. Furthermore, Plat measurement could assess the need for additional procedures in real time in patients with extensive airway obstruction.

Untreated Squamous Cell Lung Carcinoma May Contribute to the Occurrence of Hemophagocytic Syndrome.

A 44-year-old man presented at our hospital to be evaluated for persistent fever and dyspnea. A chest computed tomography (CT) scan showed diffuse ground glass shadows and a left hilar tumor shadow. Upon further examination, he was found to have leukopenia, thrombocytopenia, and elevated lactate dehydrogenase and ferritin levels. He was diagnosed with both squamous cell lung carcinoma by a transbronchial lung biopsy and hemophagocytic syndrome by a bone marrow biopsy. After receiving treatment with dexamethasone and etoposide, the blood test abnormalities and performance status improved. Chemotherapy for lung cancer was initiated. He had a partial response after first-line chemotherapy and thereafter underwent left upper sleeve lobectomy.

Correlation between Computed Tomographic Analysis and Pulmonary Function Measurements in Patients with Relapsing Polychondritis.

BACKGROUND: Relapsing polychondritis (RP) is a rare systemic disease of unknown origin, with cartilaginous involvement in multiple organs. Airway involvement is the most important prognostic factor in RP. OBJECTIVES: Spirometric measurements and minimum tracheal cross-sectional area (mtCSA) have been reported as useful to assess the degree of airway stenosis. Because the length and severity of tracheal involvement in RP can vary, mtCSA might not provide enough information to assess tracheal abnormalities. We introduced tracheal volume (TrV) as a new method to evaluate correlations between chest computed tomography (CT) measurements and pulmonary function tests, including impulse oscillometry (IOS). METHOD: We analyzed chest CT images, spirometry, and IOS collected at our institution from April 2004 to March 2019. We calculated correlations between chest CT measurements using software (TrV, TrV/tracheal length [TrV/TL], and mtCSA) and pulmonary function parameters. RESULTS: Twenty-five of 73 clinically diagnosed patients with RP were included. Spirometric findings showed moderate airway obstruction. Peak flow (PEF) was strongly correlated with mtCSA, TrV, and TrV/TL (ρ = 0.74, p < 0.001). FEV1 was significantly correlated with mtCSA (ρ = 0.56, p = 0.004), TrV (ρ = 0.52, p = 0.007), and TrV/TL (ρ = 0.53, p = 0.006). Whereas respiratory resistance at 5 Hz (R5) and 20 Hz (R20) and resonant frequencies (RFs) were significantly correlated with TrV (ρ = -0.46, p = 0.021; ρ = -0.46, p = 0.046; and ρ = -0.42, p = 0.037, respectively), IOS parameters and mtCSA were not. CONCLUSIONS: In patients with RP, TrV and mtCSA were strongly correlated with spirometric measurements. Respiratory resistances assessed by IOS correlated only with TrV. This suggests TrV assessment reflects pulmonary function in patients with RP more appropriately than mtCSA.

Development and Clinical Application of a Novel Non-contact Early Airflow Limitation Screening System Using an Infrared Time-of-Flight Depth Image Sensor.

Obstructive pulmonary diseases, such as diffuse panbronchiolitis (DPB), asthma, chronic obstructive pulmonary disease (COPD), and asthma COPD overlap syndrome (ACOS) trigger a severe reaction at some situations. Detecting early airflow limitation caused by diseases above is critical to stop the progression. Thus, there is a need for tools to enable self-screening of early airflow limitation at home. Here, we developed a novel non-contact early airflow limitation screening system (EAFL-SS) that does not require calibration to the individual by a spirometer. The system is based on an infrared time-of-flight (ToF) depth image sensor, which is integrated into several smartphones for photography focusing or augmented reality. The EAFL-SS comprised an 850 nm infrared ToF depth image sensor (224 × 171 pixels) and custom-built data processing algorithms to visualize anterior-thorax three-dimensional motions in real-time. Multiple linear regression analysis was used to determine the amount of air compulsorily exhaled after maximal inspiration (referred to as the forced vital capacity, FVC EAFL -SS) from the ToF-derived anterior-thorax forced vital capacity (FVC), height, and body mass index as explanatory variables and spirometer-derived FVC as the objective variable. The non-contact measurement is automatically started when an examinee is sitting 35 cm away from the EAFL-SS. A clinical test was conducted with 32 COPD patients (27/5 M/F, 67-93 years) as typical airflow limitation cases recruited at St. Marianna University Hospital and 21 healthy volunteers (10/11 M/F, 23-79 years). The EAFL-SS was used to monitor the respiration of examinees during forced exhalation while sitting still, and a spirometer was used simultaneously as a reference. The forced expiratory volume in 1 s (FEV1% EAFL -SS) was evaluated as a percentage of the FVC EAFL -SS, where values less than 70% indicated suspected airflow limitation. Leave-one-out cross-validation analysis revealed that this system provided 81% sensitivity and 90% specificity. Further, the FEV1 EAFL -SS values were closely correlated with that measured using a spirometer (r = 0.85, p < 0.0001). Hence, EAFL-SS appears promising for early airflow limitation screening at home.

The peripheral lymphocyte count as a predictor of severe COVID-19 and the effect of treatment with ciclesonide.

We investigated whether reduced lymphocyte count, could predict the development of severe COVID-19. We also examined whether ciclesonide could prevent the development of severe COVID-19 among patients with the predictors. This was a retrospective cohort study. Of the 30 included patients, 12, 14, and 4 were allocated to severe pneumonia, non-severe pneumonia, and non-pneumonia groups, respectively. The group of the low level of lymphocyte counts of the sixth day after onset was significantly intubated approximately three days later. The incidence of the severe pneumoniae requiring intubation are significantly lower in the patients treated with ciclesonide than without it (11.18 % vs 83.33 %, p = 0.0033). The lymphocyte count after ciclesonide treatment in the non-severe pneumonia group was significantly higher (p = 0. 0156) than before. The lymphocyte count could be used to identify patients that may develop severe COVID-19. Treatment with ciclesonide may prevent the development of severe COVID-19.

Pulmonary Perfusion Using Intrabronchial Capnography in Pulmonary Artery Stenosis.

Stenting at the flow-limiting segment can improve the ventilation-perfusion ratio in patients with central airway stenosis. However, there is no quantitative examination for assessing the perfusion status during interventional bronchoscopy. Intrabronchial capnography can estimate regional gas exchange by measuring carbon dioxide concentration. We herein report a case of bilateral bronchial stenosis where stenting was able to improve ventilation-perfusion ratio using intrabronchial capnography. A 44-year-old man was admitted to our institution with orthopnea. Chest computed tomography showed an extrinsic compression at the bilateral main bronchus and right pulmonary artery due to a mediastinal mass. After introduction of general anesthesia, arterial oxygen tension suddenly decreased in the supine position. After initial stenting, an increase was seen in ventilation at the right lung; however, a ventilation-perfusion mismatch occurred due to an increase in dead-space ventilation at the right pulmonary artery stenosis. Intrabronchial capnography was an effective modality to confirm the regional perfusion status during interventional bronchoscopy in real time.

Assessment of Bronchial Obstruction Using Lateral Pressure Measurement during Bronchoscopy.

BACKGROUND: In patients with bronchial obstruction estimating the location of the maximal obstruction is crucial for guiding interventional bronchoscopy. However, flow-volume curves cannot discriminate between the right and left lungs. OBJECTIVES: The aim of this study was to physiologically evaluate bronchial obstruction during interventional bronchoscopy. METHODS: We prospectively measured lateral airway pressure (Plat) at either side of the obstruction using a double-lumen catheter (pressure-pressure [P-P] curve) simultaneously to assess the degree of bronchial obstruction in 22 patients. The shape of the P-P curve was assessed to confirm the site of maximal obstruction. RESULTS: In the experimental study, Plat was uniform between both bronchi in the normal model. For the unilateral and bilateral obstruction models, a phase shift was only seen for the more obstructed side. In healthy subjects, the angle of the P-P curve was close to 45° and linear in shape. In patients with bronchial obstruction, the angle was much smaller but approached 45° after the bronchoscopic procedure. The degree of bronchial obstruction was significantly correlated with the angle of the P-P curve (r = -0.51, p < 0.01). Dyspnea significantly increased when the airway lumen was obstructed by more than 60% (p < 0.0001), and when the P-P curve appeared loop-shaped (p < 0.01). CONCLUSIONS: The shape of the P-P curve could be used to detect the site of maximal obstruction for the optimal positioning of the stent and assess the need for additional procedures in real time in patients with bronchial obstruction.

Comparison of Airway Measurements for Tracheobronchial Stenosis Between Stereoscopic Bronchoscope and MD-CT.

BACKGROUND: Stereoscopic bronchoscopy is a new diagnostic tool to measure the diameter and cross-sectional area of the airway. The stereoscopic bronchoscope, which operates the same as a standard bronchoscope, utilizes 2 lenses to measure the airway using the principles of triangulation. Furthermore, the stereoscopic bronchoscope has the capability to measure the size of the airway during intervention in real-time, including variable stenosis. MATERIALS AND METHODS: To prospectively compare preoperative stereoscopic and multidetector computed tomography (MD-CT) images to select the appropriate stent size for airway stenosis. Stereoscopic and MD-CT images were then measured to confirm the correct placement of the stent. RESULTS: Airway stenting was performed on 21 consecutive patients of whom, 15 were diagnosed with malignant and 6 with benign diseases. In total, 165 measurements were taken (134 healthy; 31 affected). For the diameter, Bland-Altman plots were used to measure data from 165 matched stereoscopic and MD-CT measurement sites (bias, 0.40±2.86 mm SD; percentage error, 33%), 134 healthy sites (bias, 0.554±2.83 mm SD; percentage error, 34%), and 31 affected sites (bias, 1.20±2.67 mm SD; percentage error, 52%). For the cross-sectional area, matched stereoscopic and MD-CT measurements were analyzed for 65 sites (bias, -10.53±92.85 mm SD; percentage error, 89%), 49 healthy sites (bias, -9.88±39.00 mm SD; percentage error, 32%), and 16 affected sites (bias, -13.12±48.81 mm SD; percentage error, 92%). CONCLUSION: Stereoscopic bronchoscopy was able to accurately measure the size of the airway during intervention, to assist in selecting the appropriate size of the stent.

Regional Lung Sound Asynchrony in Chronic Obstructive Pulmonary Disease Patients.

BACKGROUND: Regional lung sound distribution in chronic obstructive pulmonary disease (COPD) is reported to be asynchronous. Mathematical analyses using vibration response imaging (VRI), such as left and right lung asynchrony (gap index; GI) and regional lung asynchrony (asynchrony score; AS), are useful measures to evaluate lung sound asynchrony. OBJECTIVES: The aim of this study was to investigate the association of lung sound asynchrony with pulmonary functions and emphysematous lesions in COPD patients. METHODS: VRI recordings and pulmonary function tests were performed in 46 stable male COPD patients and in 40 healthy male smokers. Lung sound asynchrony was evaluated using GI, AS of the left and right lung (AS L-R), and AS of the upper and lower lung (AS U-L). In 38 patients, computed tomography taken within 6 months was available and analyzed. RESULTS: AS L-R and AS U-L were significantly higher in COPD patients than in healthy smokers, with no significant difference in GI. There were no significant correlations with either AS and pulmonary functions, excluding a negative correlation between AS U-L and diffusion capacity. Although there were no significant correlations between both AS and severity of emphysema, significant positive correlations were observed between heterogeneity of emphysematous lesions and AS L-R (ρ = 0.38, p < 0.05) or AS U-L (ρ = 0.51, p < 0.005). CONCLUSIONS: Regional lung sounds are distributed more asynchronously in COPD patients than in healthy smokers, which correlates with the heterogeneous distribution of emphysematous lesions.

Choke point physiology in airway stenting: A case presentation and discussion.

BACKGROUND: The point in the airway that allows the smallest maximal flow is known as the "choke point". The tube law describes the velocity of the expired air, which cannot exceed the wave-speed. Flow limitation during forced expiration is affected by the relationship between the transmural pressure (Ptm) and cross-sectional area (A) of the airway. Wave speed is dependent on the stiffness of the airway wall, as well as on the cross-section of the airway itself (dA/dPtm). METHODS: Airway stenting at the wave-speed, flow-limiting segment (choke point) is assessed by using a catheter, via the working channel of a stereoscopic bronchoscope, to measure the difference between lateral pressure and pleural pressure. RESULTS: Based on the wave-speed concept of maximal expiratory flow limitation, stenting at the choke point increased the cross-sectional area and supported the weakened airway wall, thus improving expiratory flow limitation and relieving dyspnea. CONCLUSION: To ensure correct stent positioning and thus optimal functional benefit, it is important to locate the exact position of tracheobronchial stenosis.

Broncholithiasis Assessed by Bronchoscopic Saline Solution Injection.

A 68-year-old man was admitted with hemoptysis. Bronchoscopy showed bronchial obstruction at the right B(3)bii proximal to the broncholith. The distal end of the bronchoscope was placed in a wedge position at the right B(3)bii. After repeated injection of saline solution through the working channel of the bronchoscope, we observed that the broncholith was freed from the bronchial wall. The broncholith was easily removed with forceps through the working channel of the bronchoscope. Bronchoscopic saline solution injection was safe and effective in confirming the mobility of the broncholith as bronchoscopy alone could not detect the broncholiths due to bronchial occlusion.

Intractable pneumothorax managed by talc pleurodesis and bronchial occlusion with spigots.

Three cases of inoperable secondary spontaneous pneumothorax were diagnosed in patients with chronic obstructive pulmonary disease. Two cases initially underwent bronchial occlusion with endobronchial Watanabe spigot (EWS), while one underwent talc poudrage with pleuroscopy. As air leaks were not stopped completely in all cases with the initial procedures, we performed additional interventional treatments: pleuroscopic talc poudrage in cases when bronchial occlusion was performed first; and bronchial occlusion with EWS for a case that initially underwent talc pleurodesis. The air leaks ceased in all cases without complication. We successfully removed chest tubes 2-10 days after secondary procedure, which was 10-23 days after the first procedure. The combination of talc pleurodesis and bronchial occlusion with EWS, when a single, initial interventional treatment fails, can be considered in cases of intractable, inoperable secondary pneumothorax.