BACKGROUND: The functional status and outcomes in patients with prolonged mechanical ventilation (PMV) are often limited by poor endurance and pulmonary mechanics, which result from the primary diseases or prolonged time bedridden. We evaluate the impact of exercise training on pulmonary mechanics, physical functional status, and hospitalization outcomes in PMV patients. METHODS: Twenty-seven subjects with PMV in our respiratory care center (RCC) were divided randomly into an exercise training group ( n = 12) and a control group ( n = 15). The exercise program comprised 10 sessions of exercise training. The measurement of pulmonary mechanics and physical functional status (Functional Independence Measurement and Barthel index) were performed pre-study and post-study. The hospitalization outcomes included: days of mechanical ventilation, hospitalization days, and weaning and mortality rates during RCC stay. RESULTS: The training group had significant improvement in tidal volume (143.6 mL vs 192.5 mL, P = .02) and rapid shallow breathing index after training (162.2 vs 110.6, P = .009). No significant change was found in the control group except respiratory rate. Both groups had significant improvement in functional status during the study. However, the training group had greater changes in FIM score than the control group (44.6 vs 34.2, P = .024). The training group also had shorter RCC stay and higher weaning and survival rates than the control group, although no statistical difference was found. CONCLUSIONS: Subjects with PMV in our RCC demonstrated significant improvement in pulmonary mechanics and functional status after exercise training. The application of exercise training may be helpful for PMV patients to improve hospitalization outcomes.

BACKGROUND: The performance of nebulizers varies with the design type as well as the breathing patterns of various age groups. The present study quantified aerosol delivery using spontaneously breathing parameters of a small child (2–4 years) by a lung simulator to determine the influence of nebulizer type, actuation mechanisms, and pediatric aerosol masks. METHODS: Three types of nebulizer (constant-output, breath-enhanced, and breath-actuated nebulizer) and 3 masks (standard pediatric mask, the Fish mask, and a valved mask) were chosen for the testing. The actuation mechanism of the breath-actuated nebulizer was tested by manual synchronization with inspiration, breath actuation, and continuous nebulization. The nebulizer performance was determined by determining mass median aerodynamic diameter and analyzing drug deposition distal to the trachea (inhaled mass), on the face, on the mask, residual drug in the nebulizer, and the time of nebulization. The quantity of salbutamol deposited was determined by spectrophotometry (276 nm). RESULTS: Mass median aerodynamic diameter was similar across nebulizers. Breath-actuated nebulization generated a lower inhaled dose and higher nebulization time than continuous nebulization ( P = .001). Breath synchronized aerosol generation, whether breath-actuated or manually actuated, yielded 10–20 times lower inhaled mass than continuous nebulization (0.1–0.6% vs 5–11%, respectively). The AeroEclipse, operated continuously, delivered greater inhaled dose than the LC Plus ( P = .025). Higher inhaled dose was achieved with the Fish mask than standard or valved mask, with all nebulizers tested ( P = .001). CONCLUSIONS: In this model using ventilatory parameters associated with a 2–4-year-old child, breath-actuated nebulization was not as effective as continuous nebulization. Aerosol mask design can impact inhaled drug dose across the range of nebulizers tested.

PURPOSE: Muscle atrophy and diaphragm dysfunction are common with prolonged mechanical ventilation (PMV). Electrical stimulation on peripheral muscles has been shown to be beneficial in the improvement of muscle function. This study examined the effects of transcutaneous electrical diaphragmatic stimulation (TEDS) on respiratory muscle strength and weaning outcomes in patients with PMV. METHODS: Participants on ventilation for ≥21 days were randomly assigned to TEDS (n = 29) and control (n = 30) groups. The TEDS group received muscle electrical stimulation for 30 min/session/day throughout the intervention. Pulmonary function parameters (tidal volume, respiratory rate, and rapid shallow breathing index), and respiratory muscle strength (Pimax, Pemax) were assessed. The hospitalization outcome, including weaning rate and length of stay, was followed up until discharge. RESULTS: After TEDS, there was a significant increase in Pemax (10 [8–20] vs. 20 [10–22] cmH₂O, P = 0.034) in the intervention group. At the end of the study, the improvement of minute volume in the TEDS group (0.64 (−0.67) was significantly higher than the control group (−0.64 (−2.5–0.78) (P = 0.008). In the control group, there was no significant difference between pre- and post-measurement of weaning parameters. There was a significant difference between groups in the weaning rate, with a higher rate in the TEDS group (90%) when compared with that in the control group (66.7%) (P =0.021). CONCLUSION: TEDS was significantly associated with increased respiratory muscle strength in patients with PMV. TEDS may be useful to facilitate weaning in this population.

Ventilation limitation has a significant adverse effects on cardiovascular function and tissue oxygenation during exercise in patients with chronic obstructive pulmonary disease (COPD). High flow nasal cannula (HFNC) improve ventilation by washing out the anatomical dead space and providing oxygen at constant concentration. This study aimed to examine the effects of HFNC on the exercise performance and hemodynamic status in COPD patients. Fifteen patients with COPD performed two constant load exercise tests (CLET) at the 70% of maximum workload achieved at a previous incremental exercise test on arm ergometer. The CLET were performed with HFNC and with nasal cannula (NC) in random order. The hemodynamics parameters of subjects during exercises were measured by a bioelectrical impedance device. The tissue oxygenation status (oxygenated hemoglobin, deoxygenated hemoglobin (hHb), total hemoglobin) was measured by a near infrared spectrophotometer. The exercise duration was longer for HFNC test than NC test (962.9 ± 281.7 s, vs 823.9 ± 184.9 s, p < 0.05). At the end of CLET, the PetCO2 was lower for HFNC than NC (29.3 ± 5.1 mmHg vs 32.1 ± 5.5 mmHg, p < 0.05). There was no difference in cardiac output (NC: 7.5 ± 1.8 vs HFNC: 7.4 ± 3.0 L,p > 0.05), stroke volume (NC:73.5 ± 21.0 vs HFNC 67.5 ± 16.3 ml, p > 0.05). The changes of hHb in muscle tissues was significantly lower in HFNC test than that in NC test (p < 0.05). HFNC resulted in a significant decrease in CO2 production and increase in exercise duration. The application of HFNC may improve the efficiency of exercise training by allowing patients to sustain exercise for longer time.

Background and objectives: Patients with chronic obstructive pulmonary disease (COPD) suffer from impaired pulmonary function and dyspnea, which result in limited levels of physical activity, and impaired quality of life. Exercise and regular physical activity have been proven to break the vicious circle. The aim of this pilot study is to investigate the effects of a walking program on exercise capacity and quality of life in patients with COPD. Materials and Methods: Patients with COPD were randomly assigned to a pedometer group (PG) or control group (CON). Subjects in the PG walked target steps daily with a pedometer for six weeks. Before and after the program, the following measurements were performed: pulmonary function test (PFT), daily steps, Six-Minute Walk Test (6 MWT), COPD Assessment Test (CAT), and quality of life questionnaire (SF-12). Results: After this walking program, PG (n = 15) significantly improved their daily steps from 4768.4 ± 2643.3 steps to 7042.7 ± 4281.9 steps (p = 0.01). Forced vital capacity (FVC) increased from 2.5 ± 0.7 L to 2.8 ± 0.9 L (p = 0.02). CAT scores decreased from 14.9 ± 8.8 points to 11.5 ± 7.5 points (p = 0.03). In the control group (n = 11), there were no differences in any outcomes after this daily walking program. Conclusions: For patients with COPD, a daily walking program with a pedometer is beneficial in the improvement of pulmonary function, daily steps, and quality of life.