Harmeet Bedi

All Publications

• Microhemorrhage-associated tissue iron enhances the risk forAspergillus fumigatusinvasion in a mouse model of airway transplantation. Science translational medicine Hsu, J. L., Manouvakhova, O. V., Clemons, K. V., Inayathullah, M., Tu, A. B., Sobel, R. A., Tian, A., Nazik, H., Pothineni, V. R., Pasupneti, S., Jiang, X., Dhillon, G. S., Bedi, H., Rajadas, J., Haas, H., Aurelian, L., Stevens, D. A., Nicolls, M. R. 2018; 10 (429)

  Abstract

  Invasive pulmonary disease due to the moldAspergillus fumigatuscan be life-threatening in lung transplant recipients, but the risk factors remain poorly understood. To study this process, we used a tracheal allograft mouse model that recapitulates large airway changes observed in patients undergoing lung transplantation. We report that microhemorrhage-related iron content may be a major determinant ofA. fumigatusinvasion and, consequently, its virulence. Invasive growth was increased during progressive alloimmune-mediated graft rejection associated with high concentrations of ferric iron in the graft. The role of iron inA. fumigatusinvasive growth was further confirmed by showing that this invasive phenotype was increased in tracheal transplants from donor mice lacking the hemochromatosis gene (Hfe -/- ). The invasive phenotype was also increased in mouse syngrafts treated with topical iron solution and in allograft recipients receiving deferoxamine, a chelator that increases iron bioavailability to the mold. The invasive growth of the iron-intolerantA. fumigatusdouble-knockout mutant (?sreA/?cccA) was lower than that of the wild-type mold. Alloimmune-mediated microvascular damage and iron overload did not appear to impair the host's immune response. In human lung transplant recipients, positive staining for iron in lung transplant tissue was more commonly seen in endobronchial biopsy sections from transplanted airways than in biopsies from the patients' own airways. Collectively, these data identify iron as a major determinant ofA. fumigatusinvasive growth and a potential target to treat or preventA. fumigatusinfections in lung transplant patients.

  View details for PubMedID 29467298

• Foreign Bodies in the Airway: Endoscopic Methods Interventions in Pulmonary Medicine Simoff, M., Bedi, H. edited by Diaz-Jimenez, J., Rodriquez, A. Springer. 2018; 2nd: 547?569
• Innovative use of a Montgomery cannula in the bronchoscopic management of tracheal stenosis and failed tracheostomy decannulation. Respiratory medicine case reports Huang, H., Chen, C., Bedi, H., Bai, C., Li, Q., Hohenforst-Schmidt, W., Zarogoulidis, P. 2017; 22: 130?32

  Abstract

  Endoprosthesis are being used in the everyday clinical practice either as a permanent solution or transient. They can be used in both benign and malignant situations.We report a case in which a temporary Montgomery cannula is used in conjunction with therapeutic bronchoscopy to manage a patient with failed tracheostomy decannulation secondary to a distal complex tracheal stenosis.This innovative use of the Montgomery cannula allowed for successful management of the patient's tracheal stenosis and subsequent tracheostomy tube decannulation.

  View details for PubMedID 28794964

  View details for PubMedCentralID PMC5547240

• A Prediction Model to Help with the Assessment of Adenopathy in Lung Cancer (HAL). American journal of respiratory and critical care medicine O'Connell, O. J., Almeida, F. A., Simoff, M. J., Yarmus, L., Lazarus, R., Young, B., Chen, Y., Semaan, R., Saettele, T. M., Cicenia, J., Bedi, H., Kliment, C., Li, L., Sethi, S., Diaz-Mendoza, J., Feller-Kopman, D., Song, J., Gildea, T., Lee, H., Grosu, H. B., Machuzak, M., Rodriguez-Vial, M., Eapen, G. A., Jimenez, C. A., Casal, R. F., Ost, D. E. 2016

  Abstract

  Estimating the probability of finding N2 or N3 (prN2/3) malignant nodal disease on EBUS-TBNA in patients with non-small cell lung cancer (NSCLC) can facilitate the selection of subsequent management strategies.The goal of this study was to develop a clinical prediction model for estimating the prN2/3.We used the AQuIRE registry to identify patients with NSCLC with clinical radiographic stage T1-3, N0-3, M0 disease that had EBUS-TBNA for staging. The dependent variable was the presence of N2 or N3 disease (vs. N0 or N1) as assessed by EBUS-TBNA. Univariate followed by multivariable logistic regression analysis was used to develop a parsimonious clinical prediction model to estimate prN2/3. External validation was performed using data from three other hospitals.The model derivation cohort (n=633) had a 25% prevalence of malignant N2 or N3 disease. Younger age, central location, adenocarcinoma histology, and higher PET-CT N stage were associated with a higher prN2/3. Area under the ROC curve was 0.85 (95% CI, 0.82-0.89), model fit was acceptable (Hosmer-Lemeshow p=0.62, Brier score 0.125). We externally validated the model in 722 patients. Area under the ROC curve was 0.88 (95% CI, 0.85-0.90). Calibration using the general calibration model method resulted in acceptable goodness of fit (Hosmer-Lemeshow test p=0.54, Brier score 0.132).Our prediction rule can be used to estimate prN2/3 in patients with NSCLC. The model has the potential to facilitate clinical decision making in the staging of NSCLC.

  View details for PubMedID 28002683

• Bronchoscopist-directed Continuous Propofol Infusion for Targeting Moderate Sedation During Endobronchial Ultrasound Bronchoscopy: A Practical and Effective Protocol. Journal of bronchology & interventional pulmonology Chrissian, A. A., Bedi, H. 2015; 22 (3): 226-236

  Abstract

  Propofol use for sedation during routine flexible bronchoscopy is expanding. However, there are concerns over propofol's reliability in targeting moderate sedation during more complex and lengthy procedures, such as endobronchial ultrasound (EBUS) bronchoscopy. Its delivery by continuous infusion, which provides a steady sedation effect, may be a practical model for achieving reliable outcomes in this setting.We tested a continuous propofol infusion protocol targeting moderate sedation for EBUS bronchoscopy. A fixed loading rate of 125 mcg/kg/min and initial maintenance rate of 75 mcg/kg/min were used. Sedation assessments were performed every 2.5 minutes. The infusion was adjusted by a nurse under the direction of the bronchoscopist to maintain moderate sedation, normal vital signs, and patient comfort. Prospectively collected data from the first 31 patients using the protocol were analyzed.A mix of EBUS types was performed in a fellowship training environment. Median procedure duration was 51 minutes (interquartile range, 41 to 75 min). Ninety-four percent of total bronchoscopy time was spent in moderate sedation, whereas only 1.9% was occupied by agitation-related delays. Average propofol dose per case was 0.07 mg/kg/min (±0.020), and infusion adjustments were required once every 8 minutes. Sampling goals were met in all patients, and diagnostic and nodal staging accuracies were 90% and 91%, respectively. All tumor specimens sent for genetics were sufficient for analysis. There were no major procedure-related complications.Bronchoscopist-directed continuous propofol infusion is effective and practical for reliably and safely targeting moderate sedation during EBUS bronchoscopy, without sacrificing the breadth and accuracy of the procedure.

  View details for DOI 10.1097/LBR.0000000000000187

  View details for PubMedID 26165893

• Identification of Early Acute Lung Injury at Initial Evaluation in an Acute Care Setting Prior to the Onset of Respiratory Failure CHEST Levitt, J. E., Bedi, H., Calfee, C. S., Gould, M. K., Matthay, M. A. 2009; 135 (4): 936-943

  Abstract

  Despite being a focus of intensive investigation, acute lung injury (ALI) remains a major cause of morbidity and mortality. However, the current consensus definition impedes identification of patients with ALI before they require mechanical ventilation. To establish a definition of early ALI (EALI), we carried out a prospective cohort study to identify clinical predictors of progression to ALI.Potential cases of EALI were identified by daily screening of chest radiographs (CXRs) for all adult emergency department and new medicine service admissions at Stanford University Hospital.Of 1,935 screened patients with abnormal CXRs, we enrolled 100 patients admitted with bilateral opacities present < 7 days and not due exclusively to left atrial hypertension. A total of 33 of these 100 patients progressed to ALI requiring mechanical ventilation during their hospitalization. Progression to ALI was associated with immunosuppression, the modified Rapid Emergency Medicine Score, airspace opacities beyond the bases, systemic inflammatory response syndrome, and the initial oxygen requirement (> 2 L/min). On multivariate analysis, only an initial oxygen requirement > 2 L/min predicted progression to ALI (odds ratio, 8.1; 95% confidence interval, 2.7 to 24.5). A clinical diagnosis of EALI, defined by hospital admission with bilateral opacities on CXR not exclusively due to left atrial hypertension and an initial oxygen requirement of > 2 L/min, was 73% sensitive and 79% specific for progression to ALI.A new clinical definition of EALI may have value in identifying patients with ALI early in their disease course.

  View details for DOI 10.1378/chest.08-2346

  View details for Web of Science ID 000265113800012

  View details for PubMedID 19188549

  View details for PubMedCentralID PMC2758305