Francisco Javier Ruiz Ortega

A shuttle walk test for assessment of functional capacity in chronic heart failure

BACKGROUND Peak oxygen uptake (peak VO(2)) is a reference parameter in the assessment of functional capacity of patients with chronic heart failure, but the procedure for cardiopulmonary exercise testing with expired gas analysis is complex and expensive, so more simple and available methods are desirable. METHODS We compared the usefulness of a time-limited walk test, the 6-minute walk test (6-MT), with that of a symptom-limited walk test, the shuttle walk test (SWT), in the evaluation of patients with moderate to severe chronic heart failure. We prospectively studied 46 clinically stable patients in New York Heart Association class II to IV heart failure with left ventricular ejection fraction <40% (aged 53 +/- 10 years, ejection fraction 23% +/- 8%, New York Heart Association functional class 2.8 +/- 0.7). Each patient performed two 6-MT, two SWT and a cardiopulmonary exercise testing within 2 weeks. RESULTS We found a close correlation between distance walked in SWT and peak VO(2 ) (r = 0.83, P <.001) and a moderate correlation between distance in 6-MT and peak VO(2) (r = 0.69, P <.001). Both walk tests showed to be reproducible after just one practice walk. All patients who walked > 450 m in SWT had a peak VO(2) >14 mL/kg/min. The overall discriminatory accuracy for SWT distance was greater than that for 6-MT distance for predicting a peak VO(2 ) <14 mL/kg/min (area under receiver operator characteristic curves 0.97 and 0.83 respectively, P =.02). Stepwise multivariate regression analysis, including clinical, exercise testing, echocardiographic, radionuclide-angiographic, and rest hemodynamic data, showed that distance walked in SWT was the only independent predictor of peak VO(2) (P <.001) and the strongest predictor of percent achieved of age- and sex-predicted peak VO(2) (%PVO(2)) (P <.001), with only age offering additional information (P =.02). CONCLUSIONS The SWT shows to be a feasible and safe method to evaluate patients with chronic heart failure that strongly and independently predicts peak VO(2) and %PVO(2.) This symptom-limited walk test seems to be more useful than 6-MT in the assessment of functional capacity in these patients.

Benefits of Long-Term Pulmonary Rehabilitation Maintenance Program in Patients with Severe Chronic Obstructive Pulmonary Disease. Three-Year Follow-up

Rationale: In chronic obstructive pulmonary disease (COPD), the benefits of pulmonary rehabilitation (PR) tend to wane over time. Whether maintenance techniques may help sustain the benefits achieved after completion of the initial PR program remains controversial. Objectives: To determine whether a long‐term (3‐yr) maintenance program after PR preserves the short‐term effects on outcomes in patients with COPD. Methods: This was a multicenter prospective randomized trial including 143 patients with moderate‐severe COPD, with 3 years of PR maintenance following an 8‐week outpatient PR program. Patients were randomized to maintenance intervention group (IG) and standard monitoring program or control group (CG). The effects on BODE index, 6‐minute‐walk test distance (6MWD), and health‐related quality of life were compared at 12, 24, and 36 months. Measurements and Main Results: A total of 138 (96.5%) completed the 8‐week program. At this time, all outcomes (BODE, 6MWD, and health‐related quality of life) showed clinically and statistically significant improvements (P ≤ 0.001). During the follow‐up period, the magnitude of change in 6MWD differed between IG and CG (P = 0.042), with a slight initial increase in the IG during the first year and smaller decline afterward. The BODE index changes differed between baseline and measurements at Month 24 (P = 0.043). At 3 years, the adherence rate of IG patients was 66% and 17% for the CG group (P < 0.001). Conclusions: This study shows a 2‐year beneficial effect of a program of rehabilitation maintenance on the BODE index and 6MWD when compared with a standard strategy. This effect vanishes after the second year of follow‐up. Clinical trial registered with www.clinicaltrials.gov (NCT 01090999)

Exercise Training in Patients With Chronic Respiratory Failure Due to Kyphoscoliosis: A Randomized Controlled Trial

BACKGROUND: Research has provided evidence for the safety, feasibility, and efficacy of exercise training in patients with COPD. However, little is known about the impact of exercise training in patients with chronic respiratory failure due to kyphoscoliosis. We evaluated the effect of an exercise training program on exercise capacity, muscle strength, dyspnea, and quality-of-life indices in subjects with chronic respiratory failure due to kyphoscoliosis. METHODS: The 34 subjects were clinically stable, had been receiving nighttime home mechanical ventilation for ≥ 6 months, and were randomly assigned to the exercise group (n = 17) or the control group (n = 17). The exercise group conducted cycle and strength training on 3 non-consecutive days per week for 12 weeks. We measured pulmonary function, exercise capacity, peripheral muscle strength, dyspnea scores, and quality of life. RESULTS: Statistical analysis was carried out on the data from 16 subjects in the exercise group and in 11 subjects in the control group. Three of the lung-function parameters in the exercise group significantly changed: PaCO2 (P = .04), inspiratory pressure (P = .03), and expiratory pressure (P = .04); and endurance time (P = .002) and shuttle walk distance (P = .001) increased significantly. The exercise group had significantly greater improvements in peripheral muscle strength, dyspnea, and quality of life. CONCLUSIONS: In patients with chronic respiratory failure due to kyphoscoliosis, exercise training improved exercise capacity, peripheral muscle strength, dyspnea, and quality of life. (Deutschen Register Klinischer Studien DRKS00000443)

La argumentación en clase de ciencias, un modelo para su enseñanza

Argumentation in science is a dialogic process and a fundamental tool for the co-construction of more meaningful understandings of the concepts discussed in class. Therefore, it is one of the responsibilities to be assumed explicitly in science teaching and learning. The central aim of our research is to propose a model for teaching argumentation in science. We have collected and analyzed qualitatively information from a teacher who participates in a critical reflection process on argumentation and her own performance. The findings evidence how important it is for teachers to deepen their knowledge of epistemological, conceptual and teaching aspects, which are key to a model for teaching argumentation in science. Similarly, we show how identifying these aspects both in the teachers thought and performance, and the relationship between them, allows constructing a model for teaching science argumentation.

Desarrollo de la mirada profesional sobre la argumentación científica en el aula de secundaria

This study attempts to show a teacher professional noticing on scientific argumentation in the high school classroomof a future teachers program in the Colombian context. Argumentation in high school requires a relationship among three aspects (conceptual, didactic and structural). The characterization of this professional competence involves the development of three main skills in pre-service teachers: Identifying the main elements in the argumentation process in science class; interpreting the said elements; and making decisions based on practice to better argumentation process in the science class. Data gathered consisted of student-teachers’ productions in relation to the activities proposed by the researchers. Activities were all based in video material previously recorded with class episodes. Results show the complexity to develop this competence within a training course. Also, some significant changes in the skills of identification and interpretation of argumentation practices were evidenced. In contrast, difficulties in decision making through reflective teaching in the practice were also identified.