Telehealth pulmonary rehabilitation: A review of the literature and an example of a nationwide initiative to improve the accessibility of pulmonary rehabilitation.

Several different applications of telehealth technologies have been used in the care of respiratory patients, including telemonitoring, teleconsultations, tele-education, and telehealth-pulmonary rehabilitation (PR). Telehealth technology provides an opportunity to assist in the management of chronic respiratory diseases and improve access to PR programs. While there is inconclusive evidence as to the effectiveness of telemonitoring to reduce healthcare utilization and detection of exacerbations, teleconsultations have been shown to be an effective means to assess patients' disease prior to the initiation of PR, and telehealth PR has been shown to be as effective as institution-based PR at improving functional exercise capacity and health-related quality of life. To improve PR access across Canada and ensure a high standard of program quality, a team of clinicians and researchers has developed and begun to implement a national standardized PR program that can be delivered across different settings of practice, including remote satellite sites via telehealth PR. The program has adapted the "Living Well with COPD" self-management program and includes standardized reference guides and resources for patients and practitioners. A progressive and iterative process will evaluate the success of program implementation and outcomes. This initiative will address nationwide accessibility challenges and provide PR content as well as evaluations that are in accordance with clinical standards and established self-management practices.

Altered breathing mechanics and ventilatory response during exercise in children born extremely preterm.

BACKGROUND: Extreme preterm birth confers risk of long-term impairments in lung function and exercise capacity. There are limited data on the factors contributing to exercise limitation following extreme preterm birth. This study examined respiratory mechanics and ventilatory response during exercise in a large cohort of children born extremely preterm (EP). METHODS: This cohort study included children 8-12 years of age who were born EP (≤28 weeks gestation) between 1997 and 2004 and treated in a large regionalised neonatal intensive care unit in western Canada. EP children were divided into no/mild bronchopulmonary dysplasia (BPD) (ie, supplementary oxygen or ventilation ceased before 36 weeks gestational age; n=53) and moderate/severe BPD (ie, continued supplementary oxygen or ventilation at 36 weeks gestational age; n=50). Age-matched control children (n=65) were born at full term. All children attempted lung function and cardiopulmonary exercise testing measurements. RESULTS: Compared with control children, EP children had lower airway flows and diffusion capacity but preserved total lung capacity. Children with moderate/severe BPD had evidence of gas trapping relative to other groups. The mean difference in exercise capacity (as measured by oxygen uptake (VO2)% predicted) in children with moderate/severe BPD was -18±5% and -14±5.0% below children with no/mild BPD and control children, respectively. Children with moderate/severe BPD demonstrated a potentiated ventilatory response and greater prevalence of expiratory flow limitation during exercise compared with other groups. Resting lung function did not correlate with exercise capacity. CONCLUSIONS: Expiratory flow limitation and an exaggerated ventilatory response contribute to respiratory limitation to exercise in children born EP with moderate/severe BPD.

The effects of heavy load carriage on physiological responses to graded exercise.

PURPOSE: Many emergency response occupations require heavy load carriage with backpacks. The purpose of this experiment was to study the effects of heavy load carriage on physiological responses and performance during graded exercise. METHODS: Fifty males (age: 28 ± 6 years, height: 182.8 ± 6.2 cm, mass: 85.4 ± 12.1 kg) provided written informed consent before completing two randomly ordered graded exercise tests to measure ventilatory threshold and peak oxygen consumption (˙VO2peak). During the loaded test, each subject carried a correctly sized and fitted 80 L backpack weighing 25 kg. Mass, volume and load distribution were consistent between all packs. Modified Balke treadmill tests were completed by walking at 1.5 m s(−1) with stage increases of 2% grade until exhaustion. RESULTS: Analysis revealed a small but significant decrease in ˙VO2 at ventilatory threshold (3.9%) and peak exercise (2.5%) under load. Power output at ventilatory threshold and ˙VO2peak were significantly decreased by 23.6 and 11.1%, respectively, and test duration was reduced by 29.8% in the loaded condition. CONCLUSIONS: While heavy load carriage had relatively small effects on physiological responses at ventilator threshold and peak exercise, the reductions in power output and test duration were more substantial. Despite the absolute mass of the pack and the large range of subject size, the only change in performance associated with body size was test duration. These results have implications for evaluation of fitness for duty in occupations where heavy load carriage is required.

Activation of the carotid chemoreflex secondary to muscle metaboreflex stimulation in men.

Recent work has shown that the carotid chemoreceptor (CC) contributes to sympathetic control of cardiovascular function during exercise, despite no evidence of increased circulating CC stimuli, suggesting enhanced CC activity/sensitivity. As interactions between metaboreceptors and chemoreceptors have been previously observed, the purpose of this study was to isolate the metaboreflex while acutely stimulating or inhibiting the CC to determine whether the metaboreflex increased CC activity/sensitivity. Fourteen young healthy men (height: 177.0 ± 2.1 cm, weight: 85.8 ± 5.5 kg, age: 24.6 ± 1.1 yr) performed three trials of 40% maximal voluntary contraction handgrip for 2 min, followed by 3 min of postexercise circulatory occlusion (PECO) to stimulate the metaboreflex. In random order, subjects either breathed room air, hypoxia (target SPo2 = 85%), or hyperoxia (FiO2 = 1.0) during the PECO to modulate the chemoreflex. After these trials, a resting hypoxia trial was conducted without handgrip or PECO. Ventilation (Ve), heart rate (HR), blood pressure, and muscle sympathetic nervous activity (MSNA) data were continuously obtained. Relative to normoxic PECO, inhibition of the CC during hyperoxic PECO resulted in lower MSNA (P = 0.038) and HR (P = 0.021). Relative to normoxic PECO, stimulation of the CC during hypoxic PECO resulted in higher HR (P < 0.001) and Ve (P < 0.001). The ventilatory and MSNA responses to hypoxic PECO were not greater than the sum of the responses to hypoxia and PECO individually, indicating that the CC are not sensitized during metaboreflex activation. These results demonstrate that stimulation of the metaboreflex activates, but does not sensitize the CC, and help explain the enhanced CC activity with exercise.