Efficacia di diversi trattamenti riabilitativi in soggetti affetti da Broncopneumopatia Cronica Ostruttiva (BPCO)

Background: International guidelines recommend pulmonary rehabilitation for COPD patients in all stages of the disease, in particular for those patients who experience exercise-related restrictions in daily physical activities. The success of Pulmonary Rehabilitation programs resides in the integration between exercise prescription , the choice of methods and patients' compliance with home training. Several methods that can be applied to improve exercise performance in patients with COPD. One of the crucial issue for the patients is the understanding of the correct exercise intensity especially for the development of cardio-respiratory fitness (general exercise training). If the choice of method affects the area respiratory muscle training (inspiratory muscles training-IMT), normocapnic hyperventilation seems effective in improving exercise endurance in healthy subjects but few data are available for COPD patients. My PhD program consist in two studies with the common aim to evaluate the efficacy of different methods of training to improve exercise capacity and Quality of Life. Study N°1: The first study aimed to compare 2 methods of home exercise training (based on walking) titled “A simple method for home exercise training in COPD patients: 1-year study” Methods: 47 COPD were recruited and underwent respiratory function, exercise capacity evaluation with six minutes walking test (6MWT) and treadmill tests. Physical Activity was monitored by multisensor Armband. Patients were randomly assigned to 2 different home training methods and assessed again after 6 and 12 months. Group A1) speed walking marked by a metronome; Group A2) covering a known distance in a fixed time. Results: Thirty-six patients completed the study (77% of the enrolled patients). All subjects showed a significant improvement in 6MWT after 1 year but the improvement was higher in A1 than in A2 (p<0.05). Physical Activity levels were significantly higher at T12 vs baseline only in group A1(p<0.05). Conclusions: The use of a metronome to keep the rate of walking during the home exercise training improves the understanding of exercise intensity allowing the patients to follow the exercise prescription and to get better results. Study N°2: The second study aimed to assess the effects of 4 weeks of normocapnic hyperventilation (NH) by means of Spirotiger® titled “Inspiratory muscle training (IMT) with normocapnic hyperventilation (NH) improves respiratory muscle strength, exercise performance and ventilatory pattern in COPD patients”. Methods: 21 COPD were recruited. Respiratory function tests (FEV1, FVC, Pimax), QoL (St George's Questionnarie), 6MWT and endurance exercise performed at 75-80% of peak-work rate measured during an incremental test to the limit of tolerance (tLIM). 7 of 21 patients were instrumented with a portable inductive plethysmografhy (Lifeshirt System) to evaluate breathing pattern during tLIM. After 1 month of weekly supervised training, the patients trained at home for 4 weeks: 10 min twice a day at a breathing rate 12-24/min with a tidal volume (TV) equal to 50% of CV. Results: 6 patients dropped out (poor compliance). IMT significantly improved Pimax, QoL, exercise capacity (Tab 1). Ventilatory pattern after IMT is characterized by a significantly higher TV with no change in VE (Tab 2). Table1 FEV1(%) FVC(%) Pimax(KPa) QoL(tot) tLIM(min) 6MWt(m) preIMT 55,216,9 82,322,8 8,93 22,716,6 6,43,4 43674,5 postIMT 57,615,8 82,724,1 9,72,8* 17,512,2* 10,37,4* 466,279,7* Table2 SpO2mean(%) VE(L/min) TV(L/min) Br(b/min) preIMT 912,2 28,616,1 0,80,4 334,2 postIMT 92,31,5* 2916,4 0,90,4* 30,86,5 *p<0,05. Conclusions: After a short IMT with NH, COPD patients show a higher exercise capacity and an intriguing change in ventilatory pattern which improves oxygen saturation.