CT-Based Evaluation of the Shape of the Diaphragm Using 3D Slicer.

The diaphragm is the main inspiratory muscle and separates the thorax and the abdomen. In COPD, the evaluation of the diaphragm shape is clinically important, especially in the case of hyperinflation. However, delineating the diaphragm remains a challenge as it cannot be seen entirely on CT scans. Therefore, the lungs, ribs, sternum, and lumbar vertebrae are used as surrogate landmarks to delineate the diaphragm. We herein describe a CT-based method for evaluating the shape of the diaphragm using 3D Slicer-a free software that allows delineation of the diaphragm landmarks-in ten COPD patients. Using the segmentation performed with 3D Slicer, the diaphragm shape was reconstructed with open-source Free Pascal Compiler. From this graduated model, the length of the muscle fibers, the radius of curvature, and the area of the diaphragm-the main determinants of its function-can be measured. Inter- and intra-user variabilities were evaluated with Bland and Altman plots and linear mixed models. Except for the coronal length (p = 0.049), there were not statistically significant inter- or intra-user differences (p values ranging from 0.326 to 0.910) suggesting that this method is reproducible and repeatable. In conclusion, 3D Slicer can be applied to CT scans for determining the shape of the diaphragm in COPD patients.

Analysis of Nursing Staff Management for a Semi-intensive Pulmonology Unit During the COVID-19 Pandemic Using the Nursing Activities Score.

OBJECTIVES: During the COVID-19 pandemic, a shortage of intensive care unit beds was encountered across Europe. Opening a semi-intensive pulmonary ward freed up intensive care unit beds. This study aimed to determine the appropriate nurse staffing level for a semi-intensive pulmonology unit (SIPU) for patients with COVID-19 and to identify factors associated with an increase in nursing workload in this type of unit. METHODS: This was a retrospective study of the SIPU of the Erasme university clinics in Belgium. Nursing staff was determined with the Nursing Activities Score (NAS) during the second wave of COVID-19 in Belgium. RESULTS: During the study period, 59 patients were admitted to the SIPU, and a total of 416 NAS scores were encoded. The mean (±SD) NAS was 70.3% (±16.6%). Total NAS varied significantly depending on the reason for admission: respiratory distress (mean [SD] NAS, 71.6% [±13.9%]) or critical illness-related weakness (65.1% ± 10.9%). The items encoded were significantly different depending on the reason for admission. In multivariate analysis, body mass index > 30 (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.07-3.30) and higher Simplified Acute Physiology Score II score (OR, 1.05; 95 CI, 1.02-1.11) were associated with higher NAS. Patients admitted via the emergency department (OR, 2.45; 95% CI, 1.15-5.22) had higher NAS. Patients on noninvasive ventilation (OR, 13.65; 95% CI, 3.76-49.5) and oxygen therapy (OR, 4.29; 95% CI, 1.27-14.48) had higher NAS. High peripheral venous oxygen saturation (OR, 0.86; 95% CI, 0.78-0.94) was a predictor of lower workload. CONCLUSION: A ratio of 2 nurses to 3 patients is necessary for SIPU care of patients with COVID-19. Factors associated with higher workload were high Simplified Acute Physiology Score II score, body mass index > 30, admission via emergency room, patients on oxygen, and noninvasive ventilation.

High diagnostic yield of electromagnetic navigation bronchoscopy performed under cone beam CT guidance: results of a randomized Belgian monocentric study.

BACKGROUND: With the increasing use of low dose CT scans, numerous pulmonary nodules are detected. As majority of them are benign, development of efficient non-surgical diagnostic intervention is mandatory. Electromagnetic navigation bronchoscopy (ENB) has been developed to reach difficult to access lesions. The aim of the present study was to compare the diagnostic yield of ENB procedures performed in a classical endoscopy suite or in a hybrid room equipped by a cone beam CT (CBCT). METHODS: A monocentric randomized study was performed in the Erasme Hospital between January 2020 and December 2021. Lung nodules of maximum 30 mm of diameter were eligible. In both arms (endoscopy or CBCT suites), ENB, fluoroscopic guidance and a radial endobronchial ultrasound were used to reach the lesion. Then six trans-bronchial biopsies (TBB) and one trans-bronchial lung cryobiopsy (TBLC) were performed. Primary outcomes were the diagnostic yield and diagnostic accuracy of the procedure. RESULTS: Forty-nine patients were randomized (24 in the endoscopy and 25 in the CBCT arms). The lesion size was 15,9 ± 4,6 mm and 16,6 ± 6,0 mm respectively (mean ± SD, p = NS). The diagnostic yield of ENB performed under CBCT guidance was 80% compared to 42% when performed in the endoscopy suite under standard fluoroscopic guidance (p < 0,05). Similarly, the diagnostic accuracy in the CBCT group was 87% compared to 54% for the endoscopy group (p < 0,05). Duration of the procedure in the CBCT and endoscopy arms was 80 ± 23 and 61 ± 13 min respectively (mean ± SD, p < 0,01). Performing TBLC in addition to TBB increased the diagnostic yield by 14% (17 and 12,5% in CBCT and endoscopy suites respectively, p = NS). CONCLUSION: This study highlighted the additional value to perform ENB procedure under CBCT guidance for small size (less than 2 cm of diameter) pulmonary nodules. TRIAL REGISTRATION: Clinical trial registration number: NCT05257382.

Long-Term Follow-Up of Intralobar Bullae After Endobronchial Valve Treatment for Emphysema.

Endoscopic lung volume reduction using unidirectional endobronchial valves is a new technique in the treatment of patients with severe emphysema. However, the movements of the thoracic structures after endobronchial valves insertion are still unpredictable We report the unusual outcome of six patients after valves insertion in the left upper lobe. They all developed a complete atelectasis of the target lobe, a pneumothorax and sequential genuine bullae in the treated left lung of unknown etiology. The chest CT scan prior to the valves insertion was unremarkable. Three patients developed an air-liquid level in the bullae the day before a bacterial infection of their left lower lobe. The three other patients had an uneventful spontaneous resolution of their bullae at long-term follow-up. Therefore, a conservative attitude should be followed in this particular setting.

Development of a Medium Care Unit Using an Inexperienced Respiratory Staff: Lessons Learned during the COVID-19 Pandemic.

The different waves of the COVID-19 pandemic caused dramatic issues regarding the organization of care. In this context innovative solutions have to be developed in a timely manner to adapt to the organization of the care. The establishment of middle care (MC) units is a bright example of such an adaptation. A multidisciplinary MC team, including expert and non-expert respiratory health care personnel, was developed and trained to work in a COVID-19 MC unit. Important educational resources were set up to ensure rapid and effective training of the MC team, limiting the admission or delaying transfers to ICU and ensuring optimal management of palliative care. We conducted a retrospective analysis of patient data in the MC unit during the second COVID-19 wave in Belgium. The aim of this study was to demonstrate the feasibility of quickly developing an effective respiratory MC unit mixing respiratory expert and non-expert members from outside ICUs. The establishment of an MC unit during a pandemic is feasible and needed. MC units possibly relieve the pressure exerted on ICUs. A highly trained multidisciplinary team is key to ensuring the success of an MC unit during such kind of a pandemic.

Cryobiopsy and dye marking guided by electromagnetic navigation bronchoscopy before resection of pulmonary nodule.

BACKGROUND: Our aims were to explore the feasibility, safety, and efficacy of peroperative transbronchial lung cryobiopsy (TBLC) guided by electromagnetic navigation bronchoscopy (ENB) and ENB-guided methylene blue marking of presumably non-palpable pulmonary nodules, and to assess its impact on video-assisted thoracoscopic surgery (VATS) and postoperative lung function. METHODS: This approach was applied to 16 consecutive patients (Group A, mean age 64 years) who were compared retrospectively to a historical group of 49 patients (Group B, mean age 62 years) with similar nodules resected without guidance. The usefulness of dye marking was graded. The success rates of both ENB-guided TBLC and nodule localization through dye marking were computed. The type of resection, volume of resected parenchyma, duration of procedures, and postoperative lung function were compared between groups. Unpaired t-test, chi-square test, unpaired Wilcoxon test, and exact Fisher test were used when appropriate. RESULTS: Malignancy was pathologically proven in all patients. TBLC revealed malignancy in 9 patients in Group A. The success rate of ENB-guided dye marking was 94%. Lobectomy was less frequently performed in Group A than in Group B (p = 0.022). Forced expiratory volume in 1 s and total lung capacity were significantly less reduced in Group A than in Group B (p = 0.006 and p = 0.019, respectively). Combined procedure was longer than surgery alone (p<0.001), but its surgical part was shorter than VATS without guidance (p < 0.001). CONCLUSION: Peroperative ENB-guided TBLC with methylene blue marking of non-palpable lung nodules is feasible. A sparing lung parenchyma procedure could be achieved thanks to the ENB-guided dye marking before VATS.

Complete Response to Afatinib of an EGFR Exon 18 delE709_T710insD-Mutated Stage IV Lung Adenocarcinoma.

INTRODUCTION: Epidermal growth factor receptor (EGFR) mutations are frequently found in patients with lung adenocarcinomas, 90% being deletions in exon 19 or point mutation in exon 21. Three generations of tyrosine kinase inhibitors (TKIs) targeting EGFR mutations are available and have changed patient prognosis but less data is available on exon 18 mutations and their sensitivity to TKI therapy. Exon 18 delE709_T710insD accounts for 0.06% (16/27,294) of all EGFR mutations and is an oncogenic driver. Several partial responses to afatinib have been described. CASE DESCRIPTION: We report the first case, to the best of our knowledge, of the complete response to afatinib of a 57-year-old patient with stage IV lung adenocarcinoma with a delE709_T710insD mutation in the EGFR gene detected by next-generation sequencing. Oral afatinib was prescribed and despite treatment interruptions and dosage tapering due to cutaneous adverse events, a complete response was achieved 12 months after treatment initiation and is currently maintained at 17 months. CONCLUSION: When EGFR mutation is suspected, complete DNA sequencing of exons 18 to 21 should be carried out and we suggest that afatinib should be the first-line treatment for exon 18 delE709_T710insD-mutated advanced lung adenocarcinomas. LEARNING POINTS: Rare EGFR gene mutations are not detected by standard diagnostic kits.DNA sequencing is required to diagnose rare mutations of the EGFR gene.delE709_T710insD-mutated stage IV lung adenocarcinomas respond to afatinib.

Role of Non-Invasive Respiratory Supports in COVID-19 Acute Respiratory Failure Patients with Do Not Intubate Orders.

The current gold-standard treatment for COVID-19-related hypoxemic respiratory failure is invasive mechanical ventilation. However, do not intubate orders (DNI), prevent the use of this treatment in some cases. The aim of this study was to evaluate if non-invasive ventilatory supports can provide a good therapeutic alternative to invasive ventilation in patients with severe COVID-19 infection and a DNI. Data were collected from four centres in three European countries. Patients with severe COVID-19 infection were included. We emulated a hypothetical target trial in which outcomes were compared in patients with a DNI order treated exclusively by non-invasive respiratory support with patients who could be intubated if necessary. We set up a propensity score and an inverse probability of treatment weighting to remove confounding by indication. Four-hundred patients were included: 270 were eligible for intubation and 130 had a DNI order. The adjusted risk ratio for death among patients eligible for intubation was 0.81 (95% CI 0.46 to 1.42). The median length of stay in acute care for survivors was similar between groups (18 (10-31) vs. (19 (13-23.5); p = 0.76). The use of non-invasive respiratory support is a good compromise for patients with severe COVID-19 and a do not intubate order.

Six-Month Pulmonary Function After Venovenous Extracorporeal Membrane Oxygenation for Coronavirus Disease 2019 Patients.

OBJECTIVES: Venovenous extracorporeal membrane oxygenation has been largely used in patients with refractory acute respiratory distress syndrome due to coronavirus disease 2019. Few data on long-term pulmonary function among venovenous extracorporeal membrane oxygenation survivors are available. DESIGN: Retrospective, observational cohort. SETTING: Two mixed medical-surgical tertiary (30 beds) and secondary (22 beds) ICUs. PATIENTS: All critically ill adult coronavirus disease 2019 survivors treated with venovenous extracorporeal membrane oxygenation between March 10, and April 30, 2020. MEASUREMENTS AND MAIN RESULTS: The last available lung function and 6-minute walking tests, performed after a median of 178 days (ranges, 72-232 d) from ICU admission, were analyzed. Among the 32 coronavirus disease 2019 patients treated by venovenous extracorporeal membrane oxygenation during the study period, 11 (34%; median age 56 yr; median duration of mechanical ventilation and extracorporeal membrane oxygenation therapy of 26 and 15 d, respectively) were successfully weaned and discharged home. Spirometry was performed in nine patients; the volumetric lung function was preserved, that is, median forced vital capacity was 83% of predicted value (51-99% of predicted value), and median forced expiratory volume in 1 second was 82% of predicted value (60-99% of predicted value). Also, the median residual volume and the lung capacity were 100% of predicted value (50-140% of predicted value) and 90% of predicted value (50-100% of predicted value); only the diffusion capacity of the lung for carbon monoxide and 6-minute walking test were decreased (58% of predicted value [37-95% of predicted value] and 468 meters (365-625 meters), corresponding to [63-90% of predicted value], respectively). CONCLUSIONS: Among survivors from severe coronavirus disease 2019 pneumonia treated with venovenous extracorporeal membrane oxygenation, preserved long-term volumetric lung function with decreased diffusion capacity of lung carbon monoxide was observed.

Patent foramen ovale revealed by COVID-19 pneumonia.

BACKGROUND: Platypnea-orthodeoxia syndrome (POS) is a rare condition characterized by dyspnoea (platypnea) and arterial desaturation in the upright position resolved in the supine position (orthodeoxia). Intracardiac shunt, pulmonary ventilation-perfusion mismatch and others intrapulmonary abnormalities are involved. CASE PRESENTATION: We report a case of POS associated with two pathophysiological issues: one, cardiac POS caused by a patent foramen ovale (PFO) and second, pulmonary POS due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interstitial pneumonia. POS has resolved after recovery of coronavirus disease 2019 (COVID-19) pneumonia. CONCLUSIONS: Right-to-left interatrial shunt and intrapulmonary shunt caused by SARS-CoV-2 pneumonia contributed to refractory hypoxemia and POS. Therefore, in case of COVID-19 patient with unexplained POS, the existence of PFO must be investigated.

Trans-bronchial lung cryobiopsy in patients at high-risk of complications.

BACKGROUND: The surgical lung biopsy (SLB) is the recommended sampling technique when the pathological analysis of the lung is required in the work-up of an interstitial lung disease (ILD) but trans-bronchial lung cryobiopsy (TBLC) is increasingly recognized as an alternative approach. As TBLCs have lower mortality and morbidity risks than SLB, this study aimed to investigate the safety of TBLCs in patients at higher risk of complications and for whom SLB was not considered as an alternative. METHOD: This prospective study was conducted in two hospitals in which TBLCs were performed in patients with body mass index (BMI) > 35, and/or older than 75 years, and/or with severely impaired lung function (FVC < 50% or DLCO < 30%), and/or systolic pulmonary artery pressure > 45 mmHg, and/or a clinically significant cardiac disease. Patients with any of these risk factors constituted the high-risk group. Clinical outcomes were compared with those obtained in patients without these risk factors (low-risk group). RESULTS: Ninety-six patients were included between April 2015 and April 2020, respectively 38 and 58 in the high-risk or the low-risk group. No statistically significant difference was observed between both groups in terms of severity and rate of bleeding, pneumothorax, or duration of hospital stay (p value ranging from 0.419 to 0.914). CONCLUSION: This preliminary study on a limited number of patients suggests that TBLC appears safe in those in whom lung biopsy is at high-risk of complications according to their age, BMI, lung impairment, and cardiac comorbidities.

Nutrition evaluation and management of critically ill patients with COVID-19 during post-intensive care rehabilitation.

BACKGROUND: Among hospitalized patients with coronavirus disease 2019 (COVID-19), up to 12% may require intensive care unit (ICU) management. The aim of this prospective cohort study is to assess nutrition status and outcome in patients with COVID-19 following ICU discharge. METHODS: Patients requiring a minimum of 14 days' stay in the ICU with mechanical ventilation were included. Nutrition status was assessed at inclusion (ICU discharge) and follow-up (after 15, 30, and 60 days). All patients had standardized medical nutrition therapy with defined targets regarding energy (30 kcal/kg/d) and protein intake (1.5 g/kg/d). RESULTS: Fifteen patients were included (67% males); the median age was 60 (33-75) years old. Body mass index at ICU admission was 25.7 (IQR, 24-31) kg/m². After a median ICU stay of 33 (IQR, 26-39) days, malnutrition was present in all patients (11.3% median weight loss and/or low muscle mass based on handgrip strength measurement). Because of postintubation dysphagia in 60% of patients, enteral nutrition was administered (57% nasogastric tube; 43% percutaneous endoscopic gastrostomy). After 2 months, a significant improvement in muscle strength was observed (median handgrip strength, 64.7% [IQR, 51%-73%] of the predicted values for age vs 19% [IQR, 4.8%-28.4%] at ICU discharge [P < 0.0005]), as well as weight gain of 4.3 kg (IQR, 2.7-6.7 kg) (P < 0.0002). CONCLUSIONS: Critically ill patients with COVID-19 requiring ICU admission and mechanical ventilation have malnutrition and low muscle mass at ICU discharge. Nutrition parameters improve during rehabilitation with standardized medical nutrition therapy.

Role of the Bronchoalveolar Lavage in Noncritically Ill Patients during the SARS-CoV-2 Epidemic.

BACKGROUND: Bronchoalveolar lavage (BAL) is currently not recommended in noncritically ill patients for the diagnosis of SARS-CoV-2 infection. Indeed, the diagnosis is based on the RT-PCR test on a nasopharyngeal swab (NPS) and abnormal findings on the chest CT scan. However, the sensitivity of the NPS and the specificity of the chest CT scan are low. Results of BAL in case of negative NPS testing are underreported, especially in the subgroup of immunocompromised patients. OBJECTIVES: The added value of BAL in the management of unstable, but noncritically ill patients, suspected of having SARS-CoV-2 infection despite one previous negative NPS and the side effects of the procedure for the patients and the health-care providers, were assessed during the epidemic peak of the COVID-19 outbreak in Belgium. METHODS: This multicentric study included all consecutive noncritically ill patients hospitalized with a clinical and radiological suspicion of SARS-CoV-2 infection but with a negative NPS. BAL was performed according to a predefined decisional algorithm based on their state of immunocompetence, the chest CT scan features, and their respiratory status. RESULTS: Among the 55 patients included in the study, 14 patients were diagnosed with a SARS-CoV-2 infection. Interestingly, there was a relationship between the cycle threshold of the RT-PCR and the interval of time between the symptom onset and the BAL procedure (Pearson's correlation coefficient = 0.8, p = 0.0004). Therapeutic management was changed in 33 patients because another infectious agent was identified in 23 patients or because an alternative diagnosis was made in 10 patients. In immunocompromised patients, the impact of BAL was even more marked (change in therapy for 13/17 patients). No significant adverse event was noted for patients or health-care staff. All health-care workers remained negative for SARS-CoV-2 NPS and serology at the end of the study. CONCLUSIONS: In this real-life study, BAL can be performed safely in selected noncritically ill patients suspected of SARS-CoV-2 infection, providing significant clinical benefits that outweigh the risks.

Usefulness of surgical lung biopsies after cryobiopsies when pathological results are inconclusive or show a pattern suggestive of a nonspecific interstitial pneumonia.

BACKGROUND: Although increasing data supports the use of transbronchial lung cryobiopsies (TBLCs) for the diagnosis of diffuse parenchymal lung diseases (DPLDs), its role as an alternative to surgical lung biopsy (SLB) is still under debate. The aim of this study was to assess the benefit of additional SLBs performed in selected patients after TBLCs. METHOD: We conducted a multicentric Belgian prospective trial in which SLBs were performed after TBLCs when the pathological diagnosis was uncertain or if a nonspecific interstitial pneumonia (NSIP) pattern was observed hypothesizing that SLB could provide additional information and that a co-existent UIP pattern could be missed. RESULTS: Eighty-one patients with TBLCs performed for a DPLD were included in the study between April 2015 and December 2019. A specific histological diagnosis was obtained in 52 patients (64%) whereas no pathological diagnosis following TBLCs was obtained in 13 patients (16%) and a pattern suggestive of a NSIP was observed in 16 patients (20%). Fourteen out of these 29 patients had SLBs after TBLCs. SLBs showed a UIP pattern in 11 (79%), a pattern suggestive of a hypersensitivity pneumonitis in two (14%) and a NSIP pattern in one patient (7%). Among the 16 patients with pathological NSIP following TBLCs, six underwent a SLBs showing a UIP in five and confirming a NSIP in one patient only. A retrospective pathological analysis of patients having both procedures showed a lower diagnostic confidence and agreement among pathologists for TBLCs compared to SLBs. Major factors underlying the added value of SLBs were the bigger size of the sample as well as the subpleural localization of the biopsies. CONCLUSIONS: TBLCs are useful in the setting of DPLDs with a good diagnostic yield. However, our study suggests that SLB provides critical additional information in case TBLCs are inconclusive or show a pattern suggestive of a NSIP, questioning the accuracy of TBLC to adequately identify this histological pattern.

Diagnostic Yield of Combined Pulmonary Cryobiopsies and Electromagnetic Navigation in Small Pulmonary Nodules.

BACKGROUND: An increasing number of pulmonary nodules of unknown nature are detected as a result of screening by CT in high lung cancer risk patients. OBJECTIVES: The purposes of this study were to assess the diagnostic yield of electromagnetic navigation bronchoscopy (ENB) combined with transbronchial lung cryobiopsy (TBLC) and to compare it with standard transbronchial biopsy (TBB) in pulmonary nodules of less than 2 cm in diameter. METHODS: We prospectively included 32 patients (18 men and 14 women, mean age 68 ± 9 years) with nodules of less than 2 cm in diameter and no metastasis at 18FDG PET-CT. The nodule position was determined by ENB, radial endobronchial ultrasonography miniprobe, and fluoroscopy. Eight samples were obtained, six by TBB and two by TBLC. RESULTS: Nodule diameter averaged 16 ± 3 mm. Twenty-five nodules were malignant and 18 were surgically resected. Surgery was avoided in four patients as the biopsies revealed a benign disease. The samples obtained by TBLC were five times larger than those by TBB. The diagnostic yields of TBLC and TBB were 69% and 38%, respectively (p=0.017). Adverse events consisted in 15 mild or moderate bleedings and one pneumothorax. CONCLUSIONS: In the setting of peripheral pulmonary lesions of less than 20 mm in diameter, ENB-combined TBLC is feasible and safe, provides larger samples, and has higher diagnostic yield than TBB.

Necrotizing Microascus tracheobronchitis in a bilateral lung transplant recipient.

Invasive fungal infections are a major cause of mortality among solid organ transplant recipients. Scopulariopsis species and their teleomorph Microascus are molds found in soil and decaying organic matter. We report here the case of a woman who underwent bilateral lung transplantation for severe emphysema. On day 25 after transplantation, endobronchial green-black lesions were detected during routine endoscopy. Endobronchial swabs, biopsies, and bronchoalveolar lavage samples were positive for Microascus cirrosus. This fungal infection developed despite voriconazole given for previous persistent invasive aspergillosis. Treatment consisted of a combination of antifungal medication (voriconazole, terbinafine, amphotericin B, and caspofungin) and endoscopic resection of necrosed bronchial mucosa. A favorable clinical outcome was achieved after 7 weeks of treatment. Seven cases of Scopulariopsis/Microascus infection have been previously described in solid organ transplant recipients. Only two survived after treatment with an antifungal combination therapy including echinocandins, posaconazole, and terbinafine. In immunocompromised patients, infection by Microascus species is a rare but life-threatening event because of innate resistance to most common antifungal drugs. Our patient was successfully cured by combined therapy including intravenous voriconazole and caspofungin, oral terbinafine, and inhaled voriconazole and amphotericin B administered for 7 weeks in association with iterative endoscopic debridement to reduce fungal inoculum.

False-positive galactomannan assay in broncho-alveolar lavage after enteral nutrition solution inhalation: a case report.

Introduction. Diagnosis of invasive aspergillosis is challenging and the gold standard for definite diagnosis remains histopathological tissue examination. However, invasive procedures such as lung biopsy are often not feasible in critically ill patients. The detection of fungal cell wall components like Aspergillus galactomannan in broncho-alveolar lavage remains a key component of the diagnostic procedure. False-positive of the Aspergillus galactomannan assay is not frequent. Case presentation. We report a case of positive galactomannan in broncho-alveolar lavage fluid after enteral nutrition aspiration without signs of invasive aspergillosis. Galactomannan was positive in the enteral nutrition solution. Conclusion. Physicians should be aware of this previously unrecognized cause of false-positive galactomannan in broncho-alveolar fluid which can result in unnecessary treatments.

Effects of unilateral airway occlusion on rib motion and inspiratory intercostal activity in dogs.

Unilateral bronchial occlusion, a complication of many lung diseases, causes dyspnea but the mechanism of this symptom is uncertain. In this study, electromyographic (EMG) activity in the parasternal and external intercostal muscles in the third intercostal space and inspiratory motion of the third rib on both sides of the thorax were assessed during occlusion of a main bronchus for a single breath in anesthetized dogs. Occlusion produced a 65% increase in external intercostal EMG activity in both hemithoraces without altering parasternal EMG activity. Concomitantly, the inspiratory cranial rib motion showed a 50% decrease on both sides of the thorax. These changes were unaffected by bilateral vagotomy. However, when an external, caudally oriented force was applied to the third rib on the right or left side so that its inspiratory cranial displacement was abolished, activity in the adjacent external intercostals showed a twofold increase, but rib motion and external activity in the contralateral hemithorax remained unchanged. It is concluded that during occlusion of a main bronchus, the increase in external intercostal activity is induced by the decrease in inspiratory cranial rib displacement in both hemithoraces, and that this decrease is determined by the increase in pleural pressure swings on both sides of the mediastinum. This mechanism, combined with the decrease in PaO2, induces similar alterations when unilateral bronchial occlusion is maintained for a series of consecutive breaths.