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Abstract
The six-minute walking test (6MWT) has been widely utilized to evaluate global exercise capacity in patients with cystic fibrosis. The aim of this study was to assess the exercise capacity by 6MWT, measuring four outcome measures: walk distance, oxygen saturation and pulse rate during the walk, and breathlessness perception after the walk, in a group of cystic fibrosis adults with mild to moderate lung disease, and in healthy volunteers, as the control group. Moreover, the study examined the relationship between 6MWT outcome measures and pulmonary function in patients. Twenty-five adults (15 females, age range 18–39 years) with cystic fibrosis and 22 healthy volunteers (14 females, age range 20–45 years) performed a 6MWT following a standard protocol. Walk distance, oxygen saturation (S pO2) and pulse rate at rest and during walk, and breathlessness perception after walk assessed by visual analogue scale (VAS) were measured. Cystic fibrosis patients did not differ from healthy volunteers in walk distance (626±49 m vs. 652±46 m) and pulse rate. Patients significantly differed from healthy volunteers in S pO2during the walk (mean S pO2) (P<0·0001) and VAS (P<0·0001). In patients, S pO2during the walk significantly correlated with forced expiratory volume in 1 sec (FEV1) (P<0·0001), residual volume (RV) (P<0·001), resting S pO2(base S pO2) (P<0·001), and inspiratory capacity (IC) (P<0·01). In addition, VAS significantly correlated with resting S pO2(P<0·01) and IC (P<0·01). On the basis of regression equations by stepwise multiple regression analysis, S pO2during walk was predicted by FEV1(r2= 0·60) and VAS by IC (r2=0·31), whereas walk distance was not reliably predicted by any assessed variables. This study showed that cystic fibrosis adults with mild to moderate lung disease covered a normal walk distance with unimpaired cardiac adaptation, but experienced a significant fall in oxygen saturation and an increased breathlessness perception during exercise. Resting pulmonary function was related to oxygen saturation and breathlessness perception during walk, but contributed significantly only to the prediction of oxygen saturation. We suggest that 6MWT could be valuable for identifying patients who might experience oxygen desaturation and dyspnoea during demanding daily activities.
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References
REFERENCES
- Bilateral sequential lung transplantation: the procedure of choice for double-lung replacement.Ann Thorac Surg. 1991; 52: 438-445
- Bilateral lung transplantation for cystic fibrosis. The Toronto Lung Transplant Group.J Thorac Cardiovasc Surg. 1992; 103: 287-293
- The relationship of the 6-min walk test to maximal oxygen consumption in transplant candidates with end-stage lung disease.Chest. 1995; 108: 452-459
- The six-minute walking test in children with cystic fibrosis: reliability and validity.Pediatr Pulmonol. 1996; 22: 85-89
- The six-minute walk test: a guide to assessment for lung transplantation.J Heart Lung Transplant. 1997; 16: 313-319
- Lung transplantation for cystic fibrosis.Eur J Pediatr Surg. 1998; 8: 208-211
- Timing and priorities for cystic fibrosis patients candidates to lung transplantation.Eur J Pediatr Surg. 1998; 8: 274-277
- A step in the right direction: assessing exercise tolerance in cystic fibrosis.Pediatr Pulmonol. 1998; 25: 278-284
- Pulmonary hemodynamics contribute to indicate priority for lung transplantation in patients with cystic fibrosis.J Thorac Cardiovasc Surg. 2000; 119: 682-689
- A 5 year clinical evaluation of a therapeutic program for patients with cystic fibrosis.J Pediatr. 1964; 65: 677-693
- Lung volumes and forced ventilatory flows.Eur Respir J. 1993; 6: 5-40
- Standardization of the measurement of transfer factor (Diffusing Capacity).Eur Respir J. 1993; 6: 41-52
- Effect of encouragement on walking test performance.Thorax. 1984; 39: 818-822
- Reproducibility of walking test results in chronic obstructive airways disease.Thorax. 1988; 43: 388-392
- Clinical measurement of dyspnea.in: Mahler DA Dyspnea. Marcel Dekker, New York1988: 149-198
- Clinical Exercise Testing. WB Saunders Company, Philadelphia1997
- Practical Statistics for Medical Research. Chapman & Hall/CRC, New York1991
- Two-, six-, and 12-minute walking test in respiratory disease.Br Med J. 1982; 284: 1607-1608
- Exercise tolerance and cardiorespiratory adjustments at peak work capacity in cystic fibrosis.Am Rev Respir Dis. 1982; 126: 211-216
- Pulmonary function and response to exercise in cystic fibrosis.Arch Dis Child. 1971; 46: 144-151
- Endurance exercise capacity in adults with cystic fibrosis.Respir Med. 1993; 87: 541-549
- Physiological and symptom determinants of exercise performance in pateints with chronic airway obstruction.Respir Med. 2000; 94: 256-263
- Effect of a home exercise training program in patients with cystic fibrosis.Chest. 1994; 105: 463-468
- Supraventicular tachycardia in patients with cystic fibrosis.Chest. 1986; 90: 239-242
- Right ventricular dysfunction in adult severe cystic fibrosis.Chest. 2000; 118: 1063-1068
- Respiratory Function in Disease. WB Saunders Company, Philadelphia1989
- Relationship between dyspnea, pulmonary function and exercise capacity in patients with cystic fibrosis.Respir Med. 1997; 91: 41-46
- Quality of life in patients with cystic fibrosis.Pediatr Pulmonol. 1997; 23: 95-100
- Fifteen-count breathlessness score: an objective measure for children.Pediatr Pulmonol. 2000; 30: 56-62
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Publication history
Accepted:
August 6,
2001
Received:
April 19,
2001
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© 2001 Harcourt Publishers Ltd. Published by Elsevier Inc.
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