Estimating maximum work rate during cardiopulmonary exercise testing from the six-minute walk distance in patients with heart failure.

Background: Exercise is recommended for patients with chronic heart failure (CHF) and its intensity is usually set as a percentage of the maximal work rate (MWR) during cardiopulmonary exercise testing (CPX) or a symptom-limited incremental test (SLIT). As these tests are not always available in cardiac rehabilitation due to logistic/cost constraints, we aimed to develop a predictive model to estimate MWR at CPX (estMWR@CPX) in CHF patients using anthropometric and clinical measures and the 6-min walk test (6 MWT), the most widely used exercise field test. Methods: This is a multicentre cross-sectional retrospective study in a cardiac rehabilitation setting. Six hundred patients with HF in New York Heart Association (NYHA) functional class I-III underwent both CPX and 6 MWT and, through multivariable linear regression analysis, we defined several predictive models to define estMWR@CPX. Results: The best model included 6 MWT, sex, age, weight, NYHA class, left ventricular ejection fraction (LVEF), smoking status and chronic obstructive pulmonary disease COPD (adjusted R2 = 0.55; 95% LoA -39 to 33 W). When LVEF was excluded as a predictor, the resulting model performed only slightly worse (adjusted R2 = 0.54; 95% LoA -42 to 34 W). Only in 34% of cases was the percentage difference between estMWR@CPX and real MWR@CPX <10% in absolute value. EstMWR@CPX tended to overestimate low values and underestimate high values of true MWR@CPX. Conclusions: Our results showed a lack of accuracy in the predictive model evaluated; therefore, for an accurate prescription of cycle-ergometer exercise training, it is necessary to assess MWR by CPX or SLIT.

Isocapnic hyperpnea with a portable device in Cystic Fibrosis: an agreement study between two different set-up modalities.

To evaluate the bias and precision of the respiratory muscle training device formulas to predict respiratory minute volume (RMV) and volume of the reservoir bag (BV) on a cohort of subjects with Cystic Fibrosis (CF). CF patients with available pulmonary function tests and maximal voluntary manoeuvres were included in the study. Vital capacity and maximal voluntary ventilation were extracted from subjects' records and then inserted to the manufacturer's formulas to obtain RMV and BV (measured setting). RMV and BV were compared according to standard and measured formulas in males and females. Sample was described and then processed using Bland-Altman analysis. Bland-Altman analysis for RMV revealed a bias and precision of 8.8 ± 29 L/min in males and 28.8 ± 16 L/min in females; 0.4 ± 0.5 L in males and 0.7 ± 0.4 L in females for BV. Concordance correlation coefficients for RMV were -0.03 in males and 0.02 in females; 0.22 in males and 0.03 in females for BV, reinforcing an unsatisfactory concordance between measured and manufacturer setting. This study shows considerable discrepancies between the two methods, making the degree of agreement not clinically acceptable. This might cause inappropriate setting and disservice to patients with CF.

Effects of a multidisciplinary care program on disability, autonomy, and nursing needs in subjects recovering from acute respiratory failure in a chronic ventilator facility.

BACKGROUND: The aim of this study was to analyze the effects of a multidisciplinary program carried out in a chronic ventilator facility on disability, autonomy, and nursing needs of patients after a prolonged ICU stay. Secondary outcome measures were survival, weaning rate, chronic ventilator facility stay, and discharge destination. METHODS: Multidisciplinary assessment, clinical stabilization, weaning attempts, and a new Disabled Patients Autonomy Planning tool to assess daily care needs were investigated in 240 subjects in a chronic ventilator facility (52 subjects after cardiovascular surgery, 60 subjects with acute respiratory failure, 71 subjects with COPD, and 57 subjects with neurological disease). RESULTS: At admission, nursing needs, disability, and autonomy differed according to diagnosis (P < .001); weaned subjects had greater nursing needs (P < .001) and disability (P = .0014) than unweaned subjects. During the stay, 13.8% of the subjects died irrespective of diagnosis (P = .12); 47% (P < .001) were weaned with significant differences (P <.007) by diagnosis. In the 207 surviving subjects, nursing needs increased as disability increased (r = 0.59, P < .001) and autonomy decreased (r = -0.66, P < .001); disability and autonomy were inter-related (r = 0.61, P < .001). Oxygen saturation, hypercapnia, dyspnea, disability, autonomy, and nursing needs significantly improved (all, P < .001). Fifty-nine percent of the subjects were discharged home. Subjects discharged to nursing homes presented mainly neurological diseases, being more disabled and less autonomous, with higher nursing needs (all, P < .04). Mechanical ventilation use and tracheostomy increased the probability of being discharged to a nursing home (odds ratio [OR] of 1.84, P = .04; OR 2.47, P = .003, respectively). Mortality was higher in subjects who were ventilated (OR 8.44, P < .001), male (OR 2.64, P = .01), elderly (P < .001), or malnourished (P = .01) and in subjects with low autonomy (P < .001), greater nursing needs (P = .002), and more severe disabilities (P = .04). CONCLUSIONS: A specialized tailored multidisciplinary program in subjects after an ICU stay contributed to recovery from disability, autonomy, and fewer nursing needs irrespective of diagnosis. Subjects discharged to a nursing home were the most severely disabled.