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Efficacia di diversi trattamenti riabilitativi in soggetti affetti da Broncopneumopatia Cronica Ostruttiva (BPCO)
No full textBackground:
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
Field testing of ventilatory responses associated with walking and walking with poles(Nordicwalking)
No full textNordic walking, (NW) is a healthy physical activity reported to significantly increase O2 consumption and energy expenditure compared to regular walking (W). No information is available about the effect of NW on ventilatory pattern.Aim: to compare the ventilatory responses of NW to W under field-testing conditions in healthy subjects.Methods: 8 NW trainers (M,age 31-49) were studied by means of portable inductive plethysmography (Lifeshirt, Vivometrics, CA) at rest and during both NW and W at 2 speeds: 3km/h and 5km/h.Subjects performed either W or NW in a randomized manner with 1 hour rest in between.Subjects walked on a level, 420-m track with speed paced by a metronome.We measured minute ventilation (VE), tidal volume (VT), respiratory rate (ƒ), contribution of rib cage to ventilation (RC%) an index of thoracoabdominal coordination (phase angle, Φ°) and Borg scale.Anova test was used for statistical evaluation.
Ventilatoy variables during W and NW at 2 speeds Rest W 3km/h W 5km/h NW 3km/h NW 5 km/h
VE L/min 10,2±6 23,4±8§ 26,99±8°§ 39,6±18§ * 43,76±18 °§*
VT mL 444±240 937±367§ 1042±379°§ 1230±448§* 1446±661§*
ƒ 20,6±4 24,8±3§ 26±2§ 32±8§* 31±6§*
RC% 53,2±19 49,9±19 50,3±21 53,2±18 51,3±21
Φ ° 17,3±9,1 13,8±4,8 11,8±3 20,7±8,9* 12±9°
Borg scale 0 0,6±0,5§ 1,8±1§° 2,5±1,5§* 4,6±1,7§°*
* = p<0.05 vs W at the same speed; ° p <0.05 vs same condition at different speed; § vs restResults (mean ±SD): VE, VT, ƒ and Borg scale are significantly higher during NW than W at both speeds. Conclusion: the involvement of ventilation and the perceived exertion are significantly higher during NW than during W; NW might be proposed as a suitable method for respiratory training
Strong Exercise at High Altitude (HA) Reduces Thoraco-Abdominal Coordination
No full textA well known response to HA is the hyperventilation occurring >3000m. Not only the ventilation but also the ventilatory pattern may be a key point of acclimatization especially during exercise. Aim: to study ventilation at rest and during exercise in 8 elite climbers (M, age 36-52) during the Italian Everest expedition. Subjects were studied at sea level and at 5300m (Everest North Base Camp, 1stday), reached after 7 days >3500m. Breathing patterns and ventilation were continuously monitored by respiratory inductive plethysmograph (LifeShirt, VivoMetrics, CA, USA). Measurements were made at rest (30 monitoring) and during exercise. At sea level: a cardiopulmonary exercise test was performed. At HA the climbers covered a set route around base camp. The distance, the slope and the speed were monitored in each subject by means of a portable global positioning system (GPS). Results expressed as mean valueSD. At HA: total time of exercise 17,5min8; distance 905,884400m; slope 9,2%2,3; speed 0,95m/s0,012. A significant inverse correlation has been found between RC% and: speed (r=0,72 p=0,02), slope (r=0,58 p=0,028), difference in altitude (r=0,88 p=0,01) and the SpO2% rest-exercise (r=0,58 p=0,028).Conclusions: acute exposure to hypoxia induces an increase in ventilation both at rest and during exercise; during the first days of acclimatization the subjects climbing with a slower step show a better thoracoabdominal coordination and a lower decrease of SpO2 during exercise This results should be taken into account when planning the ascent profile and the physical effort during HA mountaineering
Ventilazione ed esercizio
No full textRelazione tra esercizio fisico e ventilazione .Descrizione del pattern ventilatorio e del lavoro della mucolatura respiratoria durante esercizio
High-altitude exposure reduces inspiratory muscle strength.
No full textIt was the aim of the study to assess the maximal pressure generated by the inspiratory muscles (MIP) during exposure to different levels of altitude (i.e., hypobaric hypoxia). Eight lowlanders (2 females and 6 males), aged 27 - 46 years, participated in the study. After being evaluated at sea level, the subjects spent seven days at altitudes of more than 3000 metres. On the first day, they rode in a cable car from 1200 to 3200 metres and performed the first test after 45 - 60 minutes rest; they then walked for two hours to a mountain refuge at 3600 metres, where they spent three nights (days 2 - 3); on day 4, they walked for four hours over a glacier to reach Capanna Regina Margherita (4559 m), where they spent days 5 - 7. MIP, flow-volume curve and SpO (2) % were measured at each altitude, and acute mountain sickness (Lake Louise score) was recorded. Increasing altitude led to a significant decrease in resting SpO (2) % (from 98 % to 80 %) and MIP (from 134 to 111 cmH (2)O) (baseline to day 4: p < 0.05); there was an improvement in SpO (2) % and a slight increase in MIP during the subsequent days at the same altitude. Expiratory (but not inspiratory) flows increased, and forced vital capacity and FEF (75) decreased at higher altitudes. We conclude that exposure to high altitude hypoxia reduces the strength of the respiratory muscles, as demonstrated by the reduction in MIP and the lack of an increase in peak inspiratory flows. This reduction is more marked during the first days of exposure to the same altitude, and tends to recover during the acclimatisation process
Ventilatory pattern and oxygen saturation(SpO2) in Lowlanders (LL) and Highlanders (HL) during exercise at high altitude (HA)
No full textVentilatory response is a hallmark of HA acclimatization. We aimed to compare ventilation in LL and HL at rest and during a standardized exercise. Methods: 2 groups of healthy subjects were studied at Shigatse (4200m, Tibet) : 6 HL, M (age 17-19yrs); 6 acclimatized LL (3M,3F) (age 26-35 yrs). All were monitored by means of portable respiratory inductive plethysmography (LifeShirt, VivoMetrics, CA, USA) both at rest and during strenuous walking on a slope with a 50m difference in height. Results: Ventilatory parameters at rest, at 50% and 80% of the predicted maximal heart rate(HRmax) are reported. In HL the breathing rate( RR) was 22.4(1.3), 36.0 (2.6)*°, 47.2(3.2)* br/min; the tidal volume (TV) was 381(56), 703(104)*°, 1264(122) * mL; the ventilation (VE) was 10.1(1.2), 24.2(2.4)*° , 58.4(4.2) * L/min; SaO2% was 85.3(1.1) , 85.3(1.5) °, 81.0(1.4) *. In LL , RR was 18.4 (1,7), 24.3(2.4)*°, 35.1(1.9) * br/min; TV was 445(67), 778(129)*°, 1316(127)* mL; VE was 7.6(0.6), 17.3(2.9)*°, 44.5(3.0)* L/min; SaO2% was 83.3(0.8) ,79.9(1.1)*°, 74.6(1.5)*. HL vs LL show a significantly higher RR at each point [22.4(1.3) vs 18.4 (1,7); 36.0 (2.6) vs 24.3(2.4); 47.2(3.2) vs 35.1(1.9) p<0.01], a significantly higher VE at 80%HRmax [58.4(4.2) vs 44.5(3.0) p=0.02] and a significantly higher SaO2% during exercise (at 50% and 80% HRmax ): [ 85.3(1.5) vs 79.9(1.1); 81.0(1.4) vs 74.6(1.5) p<0.05]. The % increase in VE, RR and TV was not different in the 2 groups. We conclude that acclimatized LL and HL have the same increase in ventilation during exercise at HA but highlanders’ ventilation is characterized by higher RR in all condition and a higher VE during strenuous exercise. This different ventilatory pattern in the HL is accompanied by lower oxygen desaturation during exercise. This fact suggests the adaptation of body’s ability to cope with strenuous exercise and hypoxic stress
A simple method for home exercise training in patients with chronic obstructive pulmonary disease: One-year study
No full textPURPOSE: The success of long-term exercise training (ExT) programs resides in the integration between exercise prescription and patient compliance with home training. One of the crucial issues for the patients is the understanding of appropriate exercise intensity. We compared 2 methods of home ExT, based on walking. METHODS: Forty-seven patients with chronic obstructive pulmonary disease were recruited and underwent respiratory function, exercise capacity evaluation with a 6-minute walk test, and treadmill tests. Physical activity was monitored by a multisensor Armband (SenseWear, Body Media, Pittsburgh, PA). Patients were randomly assigned to 2 different home training methods and assessed again after 6 and 12 months; group A1: speed walking paced by a metronome, and group A2: walking a known distance in a fixed time. RESULTS: Thirty-six patients completed the study. All subjects showed a significant improvement in the 6-minute walk test after 1 year but the improvement was higher in A1 than in A2 (P < .05). Physical activity levels were significantly higher at T12 versus baseline only in group A1 (P < .05). CONCLUSIONS: The use of a metronome to maintain the rate of walking during home ExT seems to be beneficial, allowing patients to achieve and sustain the optimal exercise intensity, and resulting in greater improvement compared to simply using a fixed time interval exercise. © 2012 Lippincott Williams & Wilkins, Inc
Reduced Ventilation Response during Acclimatization May Help in Reaching the Summit of Mt. Everest or K2 without Oxygen
No full textRationale. We tested whether higher ventilation and higher ventilatory responses to hypoxia were necessary prerequisites to climb Everest or K2 without oxygen.
Methods. We studied elite 11 climbers of the 2004 Italian Expedition to Everest and K2 - at sea level (SL), after arriving at the Everest base camp (5200m, HA-1), and after 15 days of acclimatization (HA-2). We measured resting oxygen saturation (SaO2) minute ventilation (Vm), breathing rate (BR), hypoxic ventilatory response (HVR), vital capacity, maximal voluntary ventilation (MVV), ventilatory reserve (RESERVE) at SaO2=70% (defined as 100 x (MVV- Vm )/MVV), and 2 markers of ventilatory efficiency (physiological dead space/tidal volume ratio (Vd/Vt) and SaO2 / Vm ).
Results. The summits of Everest or K2 were reached 29 and 61 days after HA-2, respectively. five climbers (Group1) summited without oxygen support, 6 (Group2) did not summit (4 subjects) or used oxygen. At SL and HA-1, all variables were similar in the 2 groups. At HA-2, Group1 showed smaller increases in Vm (to 13.3±0.8 vs 19.2±0.6 L/min, p<0.001), BR (to 10.7±1.9 vs 20.2±0.8 br/min, p<0.001), HVR (to -2.14±0.51 vs –5.09±1.03 L/min/% SaO2, p<0.05), and so had greater RESERVE (66.6±6.3 vs 26.7±8.8%, p<0.01) as compared to Group2. Ventilatory efficiency was higher in Group1 (Vd/Vt : 0.09±0.01 vs 0.16±0.02, p<0.05, SaO2/Vm: 6.66±0.39 vs 4.64±0.13 %/L/min, p<0.001).
Conclusions. Despite the undoubted role of environmental, technical and psychologic factors, successful climbers had smaller increases in their responses to hypoxia during acclimatization, but consequently had greater available reserve for the summit. Ventilatory efficiency may be important in preventing excessive increases in ventilation, thus allowing a sustainable ventilation even in the extreme hypoxia at the summit
Long-term (1-year) effects of two methods of exercise training (ET) in COPD patients
No full textIntroduction: the success of long-term ET programs resides in the integration between exercise prescription and patients' compliance with home training.
Aim: to evaluate two methods to help understanding and maintaining the exercise (walking) intensity.
Methods: 36 COPD patients (9F,27M) participated to the ET program (age 72 ±8; FEV1% 48±12). T0= first evaluation: 6MWD, tests on treadmill to evaluate walking distance covered in twenty minutes (20MWD) and maximal speed, monitoring of physical activity (Armband). Patients were then divided in 2 groups for the home ET program: A1= speed walking marked by a metronome; A2=covering a known distance in a fixed time. Test were repeated after 5 and 12 months (T5;T12). Control group: 23 well matched COPD not partecipating in ET (8F,15M,age 69±7,FEV1% 52±11)
Results: Group A1-A2.
Daily METs Physical activity > 3 METs (hours) 6MWD (m) Max speed (Km/h) 20MWD (m)
A1 T0 1,22±0,13 0,39±0,38 299±87 3,7±1,1 790±292
A2 T0 1,29±0,21 0,66±0,56 261±94 3,6±1,2 726±250
A1 T5 1,31±0,16* 0,95±0,86* n.a. 4,0±1,2* 970±363*
A2 T5 1,36±0,22* 1,11±0,77* n.a. 3,9±0,3 868±334*
A1 T12 1,39±0,16*^ 0,96±0,64* 369±80* 4,5±1,2*^ 1028±335*^
A2 T12 1,33±0,25 0,97±0,67^ 315±92* 4,2±1,4* 840±320*
* vs T0 ; ^ vs T5
Control group: no significant change.Conclusions: ET performed at a metronome-marked speed allows the patient to better understand the intensity of exercise and is more effective with time, as shown by the mantaining of higher physical activity and performance after 12 months in A1 compared to A2. ^*=p<0,0
Climbing Everest and K2 without oxygen: what helps?
No full textWe tested whether higher minute ventilation (Vm) and higher hypoxic ventilatory response (HVR) were necessary prerequisites to climb Everest or K2 without oxygen, in 11 climbers at sea level (SL), on arrival at the Everest base camp (5200m, HA-1), after 15-day acclimatization (HA-2) (2004 Italian Everest-K2 Expedition).
We measured resting oxygen saturation (SaO2), Vm, breathing rate (BR), HVR, vital capacity, maximal voluntary ventilation (MVV), ventilatory reserve (RES) at SaO2=70% (defined as 100 x (MVV- Vm )/MVV), ventilatory efficiency (physiological dead space/tidal volume ratio (Vd/Vt) and SaO2/Vm ).
Within 61 days from HA-2, 5 climbers (G1) summited Everest or K2 without oxygen support, 6 climbers (G2) did not (4) or used oxygen. G1 and G2 did not differ at SL and HA-1. At HA-2, G1 showed smaller increases in Vm (to 13.3±0.8 vs 19.2±0.6 L/min, p<0.001), BR (to 10.7±1.9 vs 20.2±0.8 br/min, p<0.001), HVR (to -2.14±0.51 vs 5.09±1.03 L/min/% SaO2, p<0.05), and greater RES (66.6±6.3 vs 26.7±8.8%, p<0.01) vs G2. Ventilatory efficiency was higher in G1 (Vd/Vt: 0.09±0.01 vs 0.16±0.02, p<0.05, SaO2/Vm: 6.66±0.39 vs 4.64±0.13 %/L/min, p<0.001).
Despite environmental, technical and psychologic factors, successful climbers had smaller responses to hypoxia during acclimatization, but consequently had greater reserve for the summit. Ventilatory efficiency may prevent excessive increases in ventilation, allowing a sustainable ventilation in the extreme hypoxia at the summit
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