Shuttle walking versus maximal cycle testing: clinical correlates in patients with kyphoscoliosis

Six-minute walk test in Chinese adults with clinically stable bronchiectasis: association with clinical indices and determinants

BACKGROUND

The profiles of 6-minute walk distance (6MWD) in adults with clinically stable bronchiectasis in Chinese adult patients with bronchiectasis are unclear.

OBJECTIVES

To delineate the 6MWD by stratification of clinical indices, and to investigate the factors associated with reduced 6MWD in Chinese adults with clinically stable bronchiectasis.

METHODS

We recruited 141 adult bronchiectasis patients (mean age: 44.3 ± 13.9 years). Demography, radiology, spirometry, diffusing capacity, etiology, sputum bacteriology, modified Medical Research Council dyspnea scale (MMRC) and quality of life were assessed. The safety profile of the measurement was also examined.

RESULTS

Lower levels of 6MWD were associated with older age (>50 years), higher HRCT total score, presence of cystic bronchiectasis, bilateral bronchiectasis, reduced diffusing capacity, higher MMRC score, and higher SGRQ scores. Correlation coefficients between 6MWD and spirometry and quality of life scores were different in patients with 6MWD higher and lower than lower limit of normal. DLCO being less than 80% predicted (OR = 3.13, 95% CI: 1.32-7.43, P = 0.01) and MMRC scale between 1 and 4 (OR = 6.42, 95% CI: 2.27-18.18, P < 0.01) were the factors associated with 6MWD being less than the lower limit of normal (80% predicted value). No severe adverse events were reported.

CONCLUSION

The 6MWD could be safely measured in adult patients with bronchiectasis and is poorly associated with clinical parameters. DLCO less than 80% predicted and higher MMRC scale are independent predictors of 6MWD below the lower limit of normal. Our findings will provide a reference for management of bronchiectasis patients in mainland China.

Six minute walking distance in kyphoscoliosis patients with chronic respiratory failure

Aim

To evaluate kyphoscoliosis patients with chronic hypercapnic respiratory failure (CHRF) using the six minute walk test (6MWT) distance (6MWD) and cardio-pulmonary function tests.

Method

This prospective cross-sectional study was carried out in a tertiary training and research hospital in Turkey. Kyphoscoliosis patients with CHRF on home mechanical ventilation (HMV) followed in a respiratory intensive care unit (RICU) out-patient clinic were enrolled. Patients' demographics were recorded as well as transthoracic echocardiography (ECHO), 6MWD, spirometry, arterial blood gas (ABG) values and high resolution chest computed tomography. 6MWT results were compared with other parameters.

Results

Thirty four patients with kyphoscoliosis and chronic respiratory insufficiency admitted to our outpatient clinic were included in the study but 25 (17 M) patients underwent 6MWT (8 patients walked with oxygen supplement due to PaO₂ < 60 mm Hg). The mean 6MWD was 274.4 ± 76.2 (median 270) m and median 6MWD predicted rate was 43.7% (inter quartile ratio, IQR, 37.6% to 47.7%). Median HMV use was 3 years (IQR 2-4). 6MWD predicted rate, body mass index (BMI), HMV duration were similar in male and female patients. 6MWD correlated well with age, BMI, dyspnea score for baseline 6MWT (r: - 0.59, p < 0.002, r: - 0.58, p < 0.003, r: - 0.55, p < 0.005 respectively) but modestly with forced expiratory volume in one second, pulse rate for baseline 6MWT, pulse saturation rate, fatigue and dyspnea score at end of 6MWT (r: - 0.44, p < 0.048; r: 0.44, p < 0.027; r: - 0.43, p < 0.031; r: - 0.42, p < 0.036; r: - 0.42, p < 0.034 respectively). 6MWD predicted rate was only correlated with dyspnea score at baseline (r: - 0.46, p < 0.022). The systolic pulmonary arterial pressure (PAPs) in 6 (24%) cases was more than 40 mmHg, in whom mean PaO₂/FiO₂ was 301.4 ± 55.4 compared to 280.9 ± 50.2 in those with normal PAPs (p > 0.40).

Conclusion

The 6MWT is an easy way to evaluate physical performance limitation in kyphoscoliosis patients with chronic hypercapnic respiratory failure using home mechanical ventilation. Nearly 275 m was the mean distance walked in the 6MWT, but rather than distance in meters, the 6MWD predicted rate according to gender and body mass index equation might be a better way for deciding about physical performance of these patients. Dyspnea score at baseline before the 6MWT may be the most important point that affects 6MWD in this patient population.