Effect of bilateral lung transplantation on excessive dynamic airway collapse.

INTRODUCTION: Excessive dynamic airway collapse (EDAC) is associated with significant respiratory morbidity. It has been hypothesized that EDAC may limit the benefits of lung transplantation in chronic obstructive pulmonary disease (COPD) patients. We aim to find the effect of bilateral lung transplantation on EDAC in COPD patients. METHODS: Retrospective chart review was performed to identify patients with concomitant presence of COPD and EDAC before undergoing bilateral lung transplantation from December 2011 to December 2014. Pre- and post-transplant pulmonary function tests, flow-volume (FV) loops, computed tomography (CT) of the chest, and flexible bronchoscopies were studied. RESULTS: A total of 165 patients underwent bilateral lung transplantation during the study period. Eight patients had COPD and EDAC prior to the transplant. Post-transplantation, 7 out of 8 patients showed resolution of EDAC on expiratory CT chest and 1 patient did not have post-transplant CT chest. All eight showed no EDAC on post-transplant surveillance bronchoscopy. Post-transplant, mean predicted FEV1/FVC increased from 37% to 117% and mean predicted FEV1 increased from 20% to 61%. CONCLUSIONS: There is resolution of EDAC post-bilateral lung transplantation in this retrospective COPD patient population. EDAC should not be considered as a benefit-limiting factor to bilateral lung transplantation. However, prospective studies are required to explore potential indication.

Exercising your patient: which test(s) and when?

With the introduction of the stair climb test of surgical patients in the 1950s, the role of exercise-based testing as a useful diagnostic tool and an adjunct to conventional cardiopulmonary testing was established. Since then, we have witnessed a rapid development of numerous tests, varying in their protocols and clinical applications. The relatively simple "field tests" (shuttle walks, stair climb, 6-minute walk test) require minimal equipment and technical support, and so are generally available to physicians and patients. At the other end of the spectrum is the cardiopulmonary exercise test (CPET), more complex in its equipment requirements, technical support, and with an often complex interpretive strategy. The 6-minute walk test (6MWT), in particular, has evolved into a versatile study with diagnostic utility in many disorders, including COPD, pulmonary hypertension, interstitial lung disease, congestive heart failure, and in the pre-surgical evaluation of patients, among others. With the added dimensions of optional O(2) saturation monitoring and calculated post-exercise heart rate recovery, the 6MWT is providing important clinical information well beyond the measure of distance walked. Is it sufficiently robust and informative to replace the more demanding and less available CPET? In many instances, the clinical applications are overlapping, with the 6MWT functioning as an adequate surrogate. However, in the initial evaluation of unexplained dyspnea, in formal evaluation of impairment and disability, in detailed evaluation of congestive heart failure, and in the selected lung cancer patient prior to resection, CPET remains superior. Investigations of portable metabolic and cardiovascular monitoring devices aiming to enhance the diagnostic capabilities of 6MWT may further narrow or close the remaining gap between these two exercise studies.

Suffocation From Balloon Bronchoplasty.

Negative pressure pulmonary edema is a well-described complication of upper airway obstruction. However, the simultaneous occurrence of blood-stained secretions and petechial tracheobronchial hemorrhage are rarely recognized and a potential complication of transient intentional occlusion of the airways. We described a case of "hemorrhagic bronchial mucosa syndrome" and asymptomatic blood-tinged pulmonary edema after balloon bronchoplasty for a concentric tracheal stenosis using a flexible bronchoscopy. This was characterized by interval appearance of diffuse petechial tracheobronchial bleeding and a persistent blood-tinged alveolar effluent after sustained occlusion of the airway. The simultaneous occurrence of both phenomena in this patient suggests different degrees of injury in a common pathogenic spectrum. We postulate that sustained, complete occlusion of the airway produces variable degrees of mechanical disruption of the bronchial and alveolar vasculature that lead to the development of negative pressure pulmonary edema and tracheobronchial hemorrhage. In this case, the syndrome was self-limited and without major consequences but highlights an unrecognized potential complication of balloon bronchoplasty.

Value of impedance cardiography during 6-minute walk test in pulmonary hypertension.

BACKGROUND: Methods that predict prognosis and response to therapy in pulmonary hypertension (PH) are lacking. We tested whether the noninvasive estimation of hemodynamic parameters during 6-minute walk test (6MWT) in PH patients provides information that can improve the value of the test. METHODS: We estimated hemodynamic parameters during the 6MWT using a portable, signal-morphology-based, impedance cardiograph (PhysioFlow Enduro) with real-time wireless monitoring via a bluetooth USB adapter. RESULTS: We recruited 48 subjects in the study (30 with PH and 18 healthy controls). PH patients had significantly lower maximum stroke volume (SV) and CI and slower cardiac output (CO) acceleration and decelerations slopes during the test when compared with healthy controls. In PH patients, CI change was associated with total distance walked (R = 0.62; P < 0.001) and percentage of predicted (R = 0.4, P = 0.03), HR recovery at 1 minute (0.57, P < 0.001), 2 minutes (0.65, P < 0.001), and 3 minutes (0.66, P < 0.001). Interestingly, in PH patients CO change during the test was predominantly related to an increase in SV instead of HR. CONCLUSIONS: Estimation of hemodynamic parameters such as cardiac index during 6-minute walk test is feasible and may provide useful information in patients with PH. Clin Trans Sci 2013; Volume #: 1-7.