EXERCISE PATHOPHYSIOLOGY IN PATIENTS WITH CHRONIC MOUNTAIN SICKNESS.
Chest. 2012 Feb 2;
Authors: Groepenhoff H, Overbeek MJ, Mulè M, van der Plas M, Argiento P, Villafuerte FC, Beloka S, Faoro V, Macarlupu JL, Guenard H, de Bisschop C, Martinot JB, Vanderpool R, Penaloza D, Naeije R
Abstract
ABSTRACT: BACKGROUND:Chronic mountain sickness is characterized by a combination of excessive erythrocytosis, severe hypoxemia and pulmonary hypertension, all of which affect exercise capacity. METHODS:Thirteen chronic mountain sickness patients and 15 healthy highlander and 15 newcomer lowlander controls were investigated at an altitude of 4350m (Cerro de Pasco). All of them underwent measurements of lung diffusing capacity for nitric oxide and carbon monoxide at rest, echocardiography for estimation of mean pulmonary arterial pressure and cardiac output at rest and at exercise, and an incremental cycle ergometer cardiopulmonary exercise test. RESULTS:The chronic mountain sickness patients, the healthy highlanders and the newcomer lowlanders reached a similar maximal oxygen uptake, at 32±1, 32±2 and 33±2 ml.min(-1).kg(-1) respectively, mean ± SE, p=0.8, with ventilatory equivalents for CO(2) versus end-tidal PCO(2), measured at the anaerobic threshold, of 0.9±0.1, 1.2±0.1 and 1.4±0.1 mmHg(-1), p<0.001, arterial O(2) content of 26±1, 21±2 and 16±1 ml.dl(-1), p<0.001, diffusing capacity for carbon monoxide corrected for alveolar volume of 155±4, 150±5 and 120±3% predicted, p<0.001, with diffusing capacity for nitric oxide and carbon monoxide ratios of 4.7±0.1 at sea-level decreased to 3.6±0.1, 3.7±0.1 and 3.9±0.1, p<0.05 and a maximal exercise mean pulmonary arterial pressure at 56±4, 42±3, and 31±2 mmHg, p<0.001. CONCLUSIONS:The aerobic exercise capacity of chronic mountain sickness patients is preserved in spite of severe pulmonary hypertension and relative hypoventilation, probably by a combination of increased oxygen carrying capacity of the blood and lung diffusion, the latter being predominantly due to an increased capillary blood volume.
PMID: 22302297 [PubMed - as supplied by publisher]
The role of conventional bronchoscopy in the work-up of suspicious CT screen detected pulmonary nodules.
Chest. 2012 Feb 2;
Authors: van ‘t Westeinde SC, Horeweg N, Vernhout RM, Groen HJ, Lammers JW, Weenink C, Nackaerts K, Oudkerk M, Mali W, Thunnissen FB, de Koning HJ, van Klaveren RJ
Abstract
ABSTRACT: BACKGROUND:Up to 50% of the participants in computer tomography (CT) lung cancer screening trials have at least one pulmonary nodule. The role of a conventional bronchoscopy in the work-up of suspicious screen-detected pulmonary nodules to date is unknown. If a bronchoscopic evaluation could be eliminated, the cost-effectiveness of a screening program could be enhanced and the potential harms of bronchoscopy avoided. METHODS:All consecutive participants showing a positive test result between April 2004 and December 2008 were enrolled. The diagnostic sensitivity and negative predictive value (NPV) were calculated at the level of the suspicious nodules. In 95% of the nodules the gold standard for the outcome of the bronchoscopy was based on surgical resection specimens. RESULTS:A total of 318 suspicious lesions were evaluated by bronchoscopy in 308 subjects. The diameter of the nodules averaged 14.6 mm (SD: 8.7) while only 2.8% of nodules were> 30 mm in diameter. The sensitivity of bronchoscopy was 13.5% (95% confidence interval (CI): 9.0%-19.6%), the specificity 100%, the PPV 100% and the NPV 47.6% (95% CI: 41.8%-53.5%) Of all cancers detected, 1% was detected by bronchoscopy only and retrospectively invisible on both low-dose CT and CT with intravenous contrast. CONCLUSION:Conventional white-light bronchoscopy should not be routinely recommended for test-positive participants in a lung cancer screening program.
PMID: 22302298 [PubMed - as supplied by publisher]
Transvenous Phrenic Nerve Stimulation in Patients with Cheyne-Stokes Respiration and Congestive Heart Failure: A Safety and Proof-of-Concept Study.
Chest. 2012 Feb 2;
Authors: Zhang XL, Ding N, Wang H, Augostini R, Yang B, Xu D, Ju W, Hou X, Li X, Ni B, Cao K, George I, Wang J, Zhang SJ
Abstract
Abstract: BACKGROUND:Cheyne-Stokes respiration (CSR) is often occurred in patients with congestive heart failure (CHF) and may be a predictor for poor outcome. Phrenic nerve stimulation (PNS) may interrupt CSR in patients with CHF. We report the clinical use of transvenous PNS in CHF patients with CSR. METHODS:Nineteen CHF patients with CSR were enrolled. A single stimulation lead was placed at the junction between the superior vena cava and brachiocephalic vein or in the left pericardiophrenic vein. PNS stimulation was performed using the Eupnea System software (RespiCardia Inc., Minnetonka, MN, USA). Respiratory properties were assessed prior to and post-PNS. PNS was assessed at a maximum of 10 mA. RESULTS:Successful stimulation capture was achieved in 16 patients. Failure to capture occurred in 3 patients due to dislocation of leads. No adverse events were seen under maximum normal stimulation parameters for an overnight study. When PNS was applied following a series of central sleep apneic events, a trend towards stabilization of breathing and heart rate, as well as improvement in oxygen saturation, were seen. Compared with pre-PNS, during PNS there was a significant decrease in indices of apnea/hypopnea (33.8±9.3 vs 8.1±2.3, P = 0.00), increase in mean and minimal pulse oxygen saturation (89.7±1.6 % vs 94.3±0.9% and 80.3±3.7% vs 88.5±3.3%, all P = 0.00), and end-tidal carbon dioxide (ETCO(2)) (38.0±4.3mmHg vs 40.3±3.1mmHg, P =0.02), but no significant difference in sleep efficiency (74.6±4.1% vs 73.7±5.4%, P =0.36). CONCLUSIONS:The preliminary results showed that in a small group of patients with HF and CSR, one night of unilateral transvenous PNS improved indices of CSR and was not associated with adverse events.Clinical trial:Feasibility Study to Determine the Effects of Phrenic Nerve Stimulation in Patients with Periodic Breathing.Number: NCT00909259.
PMID: 22302299 [PubMed - as supplied by publisher]
Prognostic impact of cancer-associated stromal cells in stage I lung adenocarcinoma patients.
Chest. 2012 Feb 2;
Authors: Ito M, Ishii G, Nagai K, Maeda R, Nakano Y, Ochiai A
Abstract
Abstract: BACKGROUND:The tumor microenvironment, of which cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) are the major cellular components, plays an important role in tumor progression. This study evaluated the significance of podoplanin-positive CAFs and CD204-positive TAMs, which may reflect tumor-promoting CAFs and TAMs, as risk factors for recurrence in patients with stage I lung adenocarcinoma. METHODS:The expression of podoplanin in CAFs and CD204 in TAMs was analyzed by immunohistochemistry in 304 stage I lung adenocarcinoma patients who underwent surgical resection between September 1992 and July 2004. The recurrence-free proportion (RFP) was estimated using the Kaplan-Meier method. RESULTS:The presence of podoplanin-positive CAFs and the higher number of CD204-positive TAMs were associated with a lower 5-year RFP (p < 0.001 and p = 0.001, respectively). Podoplanin-positive CAFs was shown to be an independently statistically significant risk factor for recurrence with the highest hazard ratio (HR 3.474, p = 0.029, by multivariate Cox proportional hazards model). According to subgroup analyses combining podoplanin-positive CAFs and other independent risk factors (visceral pleural invasion and intratumoral vascular invasion), the 5-year RFPs were 95.6%, 92.3%, 80.5%, and 30.3% (p = 0.294, p = 0.067, and p < 0.001) for patients with zero, one, two, or three risk factors, respectively. CONCLUSION:Podoplanin-positive CAFs was the most powerful independent risk factor for recurrence in patients with stage I lung adenocarcinoma. Podoplanin-positive CAFs may be useful for identifying patients with a high risk of recurrence who might benefit from adjuvant chemotherapy.
PMID: 22302300 [PubMed - as supplied by publisher]
Trends in Bronchiectasis among Medicare Beneficiaries in the United States, 2000-2007.
Chest. 2012 Feb 2;
Authors: Seitz AE, Olivier KN, Adjemian J, Holland SM, Prevots DR
Abstract
Abstract: BACKGROUND:Bronchiectasis is a potentially serious condition characterized by permanent and abnormal widening of the airways, the prevalence of which is not well described. We sought to describe the trends, associated conditions and risk factors for bronchiectasis among adults ≥ 65 years. METHODS:A 5% sample of the Medicare outpatient claims database was analyzed for bronchiectasis trends among beneficiaries aged ≥ 65 years from 2000-2007. Bronchiectasis was identified using the ICD-9-CM claim diagnosis codes for acquired bronchiectasis. Period prevalence was used to describe sex and race/ethnicity specific rates and annual prevalence was used to describe trends and age specific rates. We estimated trends using Poisson regression and odds of bronchiectasis using multivariate logistic regression. RESULTS:From 2000-2007, 22,296 persons had at least one claim for bronchiectasis. The eight year period prevalence of bronchiectasis was 1106 cases/100,000 persons. Bronchiectasis increased by 8.7% per year. We identified an interaction between number of thoracic CT scans and race/ethnicity; period prevalence varied by a greater degree by number of thoracic CT scans among Asian as compared to whites or blacks. Among persons with one CT scan, Asians had a 2.5 and 3.9 fold higher period prevalence as compared to whites and blacks. CONCLUSIONS:Bronchiectasis prevalence increased significantly from 2000-2007 in the Medicare outpatient setting and varied by age, sex and race/ethnicity. This increase could be due to a true increase in the condition or increased recognition of previously undiagnosed cases.
PMID: 22302301 [PubMed - as supplied by publisher]
ABSTRACT BACKGROUND:Esophageal pressure monitoring during polysomnography in children offers a gold-standard, “preferred” assessment for work of breathing, but is not commonly used in part because prospective data on incremental clinical utility are scarce. We compared a standard pediatric apnea/hypopnea index to quantitative esophageal pressures as predictors of apnea-related neurobehavioral morbidity and treatment response. METHODS:Eighty-one children aged 7.8±2.8 [s.d.] years, including 44 boys, had traditional laboratory-based pediatric polysomnography, esophageal pressure monitoring, multiple sleep latency tests, psychiatric evaluations, parental behavior rating scales, and cognitive testing, all just before clinically indicated adenotonsillectomy, and again 7.2±0.8 months later. Esophageal pressures were used, along with nasal pressure monitoring and oro-nasal thermocouples, to identify respiratory events but also more quantitatively to determine the most negative esophageal pressure recorded, and percent of sleep time spent with pressures lower than -10 cm of water. RESULTS:Both sleep-disordered breathing and neurobehavioral measures improved after surgery. At baseline one or both quantitative esophageal pressure measures predicted a disruptive behavior disorder (DSM-IV-defined Attention-Deficit/Hyperactivity Disorder, Conduct Disorder, or Oppositional Defiant Disorder) and more sleepiness, and their future improvement after adenotonsillectomy (each p<.05). The pediatric apnea/hypopnea index did not predict these morbidities or treatment outcomes (each p>.10). Addition of respiratory effort-related arousals to the apnea/hypopnea index did not improve its predictive value. Neither the pre-operative apnea/hypopnea index nor esophageal pressures predicted baseline hyperactive behavior, cognitive performance, or their improvement after surgery. CONCLUSIONS:Quantitative esophageal pressure monitoring may add predictive value for some, if not all neurobehavioral outcomes of sleep-disordered breathing.Study registered with www.clinicaltrials.gov (NCT00233194).
PMID: 22302302 [PubMed - as supplied by publisher]
Tests of the Responsiveness of the Chronic Obstructive Pulmonary Disease (COPD) Assessment Test TM (CAT) Following Acute Exacerbation and Pulmonary Rehabilitation.
Chest. 2012 Jan 26;
Authors: Jones PW, Harding G, Wiklund I, Berry P, Tabberer M, Yu R, Leidy NK
Abstract
BACKGROUND:The chronic obstructive pulmonary disease (COPD) Assessment Test™ (CAT) is an eight-item questionnaire suitable for routine clinical use that shows reliability and validity in stable and exacerbating COPD. METHODS:Study 1 assessed CAT responsiveness to changes in health status in 67 patients during an exacerbation, (Days 1-14). Study 2 assessed CAT responsiveness in 64 patients undergoing pulmonary rehabilitation, (Days 1-42). Correlations between CAT and other outcome measures were examined. RESULTS:In Study 1, mean 14-day improvement in CAT score was -1.4 units ± 5.3 (p = 0.03). In patients judged to be responders (clinician-defined) change in score was -2.6 ± 4.4; in non-responders it was -0.2 ± 5.9. In Study 2, the mean improvement in CAT score was -2.2 ± 5.3 (p = 0.002); the effect size for the change was -0.33. Effect size for changes in the Chronic Respiratory Questionnaire – Self Administered Standardized form (CRQ-SAS) domain scores ranged from -0.02 to 0.34. Change in 6-minute walk distance was 41 ± 55 m. CAT and CRQ-SAS domain scores correlated at baseline (r = -0.54 to -0.69, p < 0.0001) and in terms of change following pulmonary rehabilitation (r = -0.39 to -0.63, p < 0.01). Correlations were less strong between change in the CAT and SGRQ in Study 1 (r<0.24), and for 6-minute walk distance (r<0.11) in Study 2. CONCLUSIONS:These studies indicate that the CAT is sensitive to changes in health status following exacerbations and is as responsive to pulmonary rehabilitation as more complex COPD health status measures.
PMID: 22281796 [PubMed - as supplied by publisher]
ABSTRACT BACKGROUND:The Registry to EValuate Early And Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL) was established to characterize the clinical course, treatment, and predictors of outcomes in patients with pulmonary arterial hypertension (PAH) in the US. To date, estimated survival based on time of patient enrollment has been established and reported. To determine whether the survival of patients with PAH has improved over recent decades, we assessed survival from time of diagnosis for the REVEAL cohort and compared these results to the estimated survival using the National Institutes of Health (NIH) prognostic equation. METHODS:Newly or previously diagnosed patients (aged ≥3 months at diagnosis) with PAH enrolled from March 2006-December 2009 at 55 US centers were included in the current analysis. RESULTS:A total of 2635 patients qualified for this analysis. One-, 3-, 5-, and 7-year survival rates from time of diagnostic right-sided heart catheterization were 85%, 68%, 57%, and 49%, respectively. For patients with idiopathic/familial PAH, survival rates were 91 ± 2%, 74 ± 2%, 65 ± 3%, and 59 ± 3% compared with estimated survival rates of 68%, 47%, 36%, and 32%, respectively, using the NIH equation. CONCLUSIONS:Comprehensive analysis of survival from time of diagnosis in a large cohort of patients with PAH suggests considerable improvements in survival in the past two decades since establishment of the NIH registry, the effects of which most likely reflect a combination of changes in treatments, improved patient support strategies, and possibly a PAH population at variance with other cohorts.ClinicalTrials.gov Registration Number: NCT00370214.
PMID: 22281797 [PubMed - as supplied by publisher]
ABSTRACTBACKGROUND:Subjective measurement of physical activity using questionnaires has prognostic value in COPD. However, their lack of accuracy and large individual variability limit their use for evaluation on an individual basis. We evaluate the capacity of the objective measurement of daily physical activity in COPD patients using accelerometers to estimate their prognostic value.METHODS:In 173 consecutive subjects with moderate-very severe COPD, daily physical activity was measured using a triaxial accelerometer providing a mean of 1-minute movement epochs as vector magnitude units (VMU). Patients were evaluated by lung function testing and six-minute walk, incremental exercise and constant-work rate tests. Patients were followed during 5-8 years and the end points were all-cause mortality, hospitalization for COPD exacerbation and annual declining FEV(1).RESULTS:After adjusting for relevant confounders, a high VMU decreases the mortality risk (adjusted hazard ratio [HR]: 0.986 [95%CI 0.981-0.992]) and in a multivariate model, comorbidity, endurance time and VMU were retained as independent predictors of mortality. The time until first admission due to COPD exacerbation was shorter for the patients with lower levels of VMU (adjusted HR: 0.989 [95%CI 0.983-0.995]). Moreover, patients with higher VMU had a lower hospitalization risk than those with a low VMU (adjusted incidence rate ratio: 0.099 [95%CI 0.033-0.293). In contrast, VMU was not identified as an independent predictor of the annual FEV(1) decline.CONCLUSION:The objective measurement of the daily physical activity in COPD patients using an accelerometer constitutes an independent prognostic factor for mortality and hospitalization due to severe exacerbation.
PMID: 22281798 [PubMed - as supplied by publisher]
EFFECT OF COMBINED REMOTE ISCHEMIC PRECONDITIONING AND POSTCONDITIONING ON PULMONARY FUNCTION IN VALVULAR HEART SURGERY.
Chest. 2012 Jan 26;
Authors: Kim JC, Shim JK, Lee S, Yoo YC, Yang SY, Kwak YL
Abstract
Abstract: BACKGROUND:The aim of this study was to evaluate the lung-protective effect of combined remote ischemic pre- and post-conditioning (RIPC(pre) plus RIPC(post)) in patients undergoing complex valvular heart surgery. METHODS:This was a randomized, placebo-controlled, and double-blind trial. Fifty-four patients were randomly allocated into the RIPC(pre) plus RIPC(post) group or Control group (1:1). Patients in the RIPC(pre) plus RIPC(post) group received three 10-min cycles of right lower limb ischemia of 250 mmHg at both 10 min after anesthetic induction and weaning from cardiopulmonary bypass. Primary endpoint was to compare postoperative PaO(2)/FiO(2). Secondary endpoints were to compare pulmonary variables, incidence of acute lung injury and inflammatory cytokines. RESULTS:In both groups, PaO(2)/FiO(2) at 24 h after operation was significantly decreased compared to each corresponding baseline value. However, intergroup comparisons of pulmonary variables including PaO(2)/FiO(2) and incidence of acute lung injury revealed no significant differences. Serum levels of interleukin-6, 8 and 10, and tumor necrosis factor-α were all significantly increased in both groups compared to each corresponding baseline value without any significant intergroup differences. There were also no significant differences in transpulmonary gradient of interleukin 6 and 10, and tumor necrosis factor-α between the groups. CONCLUSIONS:RIPC as tested in this RCT did not provide significant pulmonary benefit following complex valvular cardiac surgery.
PMID: 22281799 [PubMed - as supplied by publisher]
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