Lyndal Maxwell

Sprint Training Increases Muscle Oxidative Metabolism During High-Intensity Exercise in Patients With Type 1 Diabetes

OBJECTIVE—To investigate sprint-training effects on muscle metabolism during exercise in subjects with (type 1 diabetic group) and without (control group) type 1 diabetes. RESEARCH DESIGN AND METHODS—Eight subjects with type 1 diabetes and seven control subjects, matched for age, BMI, and maximum oxygen uptake (V̇o2peak), undertook 7 weeks of sprint training. Pretraining, subjects cycled to exhaustion at 130% V̇o2peak. Posttraining subjects performed an identical test. Vastus lateralis biopsies at rest and immediately after exercise were assayed for metabolites, high-energy phosphates, and enzymes. Arterialized venous blood drawn at rest and after exercise was analyzed for lactate and [H+]. Respiratory measures were obtained on separate days during identical tests and during submaximal tests before and after training. RESULTS—Pretraining, maximal resting activities of hexokinase, citrate synthase, and pyruvate dehydrogenase did not differ between groups. Muscle lactate accumulation with exercise was higher in type 1 diabetic than nondiabetic subjects and corresponded to indexes of glycemia (A1C, fasting plasma glucose); however, glycogenolytic and glycolytic rates were similar. Posttraining, at rest, hexokinase activity increased in type 1 diabetic subjects; in both groups, citrate synthase activity increased and pyruvate dehydrogenase activity decreased; during submaximal exercise, fat oxidation was higher; and during intense exercise, peak ventilation and carbon dioxide output, plasma lactate and [H+], muscle lactate, glycogenolytic and glycolytic rates, and ATP degradation were lower in both groups. CONCLUSIONS—High-intensity exercise training was well tolerated, reduced metabolic destabilization (of lactate, H+, glycogenolysis/glycolysis, and ATP) during intense exercise, and enhanced muscle oxidative metabolism in young adults with type 1 diabetes. The latter may have clinically important health benefits.

Moderate concentrations of supplemental oxygen worsen hypercapnia in obesity hypoventilation syndrome: a randomised crossover study

Introduction In people with obesity hypoventilation syndrome (OHS), breathing 100% oxygen increases carbon dioxide (PCO2), but its effect on pH is unknown. This study investigated the effects of moderate concentrations of supplemental oxygen on PCO2, pH, minute ventilation (VE) and physiological dead space to tidal volume ratio (VD/VT) among people with stable untreated OHS, with comparison to healthy controls. Methods In a double-blind randomised crossover study, participants breathed oxygen concentrations (FiO2) 0.28 and 0.50, each for 20 min, separated by a 45 min washout period. Arterialised-venous PCO2 (PavCO2) and pH, VE and VD/VT were measured at baseline, then every 5 min. Data were analysed using general linear model analysis. Results 28 participants were recruited (14 OHS, 14 controls). Among OHS participants (mean±SD arterial PCO2 6.7±0.5 kPa; arterial oxygen 8.9±1.4 kPa) FiO2 0.28 and 0.50 maintained oxygen saturation 98–100%. After 20 min of FiO2 0.28, PavCO2 change (ΔPavCO2) was 0.3±0.2 kPa (p=0.013), with minimal change in VE and rises in VD/VT of 1±5% (p=0.012). FiO2 0.50 increased PavCO2 by 0.5±0.4 kPa (p=0.012), induced acidaemia and increased VD/VT by 3±3% (p=0.012). VE fell by 1.2±2.1 L/min within 5 min then recovered individually to varying degrees. A negative correlation between ΔVE and ΔPavCO2 (r=−0.60, p=0.024) suggested that ventilatory responses were the key determinant of PavCO2 rises. Among controls, FiO2 0.28 and 0.50 did not change PavCO2 or pH, but FiO2 0.50 significantly increased VE and VD/VT. Conclusion Commonly used oxygen concentrations caused hypoventilation, PavCO2 rises and acidaemia among people with stable OHS. This highlights the potential dangers of this common intervention in this group.

Secretion clearance by manual hyperinflation: Possible mechanisms

Manual hyperinflation is used by physiotherapists to maintain or restore lung volume in the intubated patient. Volume restoration may be important in promoting secretion clearance, as airway closure is likely to result in a mechanical obstruction to the mucociliary apparatus. Studies have shown reversal of volume loss in this patient group using manual hyperinflation; however, the impact of volume restoration on secretion clearance has not been studied extensively. Manual hyperinflation is also used by physiotherapists to promote secretion clearance in intubated patients, with some suggesting that the technique mimics a cough. It has been proposed that the fast expiratory flows generated during cough clear secretions via mist flow, one type of two-phase gas-liquid flow. Expiratory flow rates generated during manual hyperinflation in the laboratory and clinical settings have been documented in the literature. These studies demonstrate that expiratory flow rates during manual hyperinflation are consistently...

Pulmonary rehabilitation in Australia: a national survey

OBJECTIVE To determine the current structure and content of pulmonary rehabilitation programs in Australia. DESIGN A cross sectional, observational design using a purpose designed anonymous written survey. SETTING AND PARTICIPANTS The National database of Pulmonary Rehabilitation Programs maintained by the Australian Lung Foundation was used to identify all known programs in all states and territories of Australia (n=193). All pulmonary rehabilitation programs listed on the database were included. Respondents were health professionals who coordinated programs. RESULTS The response rate was 83% (161/193). Programs were coordinated by physiotherapists (75/147, 51%) and/or nurses (49/147, 33%), were hospital based (97/147, 66%) and ran for 8 weeks or longer (95/147, 65%). Pre (145/147, 99%) and post (137/147, 93%) program assessment was undertaken using a variety of measures. The Six Minute Walk Test (138/147, 94%) was the most commonly used test of exercise capacity. Exercise training was included in 145 programs (99%). Most patients attended at least two supervised exercise sessions per week (106/147, 72%) and exercised for at least 20 minutes (135/147, 92%). Lower limb endurance, upper limb endurance, strength training, and stretching/flexibility exercises were the most commonly included modes of exercise. Intensity prescription for exercise training was variable. Many respondents (93/147, 63%) indicated that they perceived a gap between their clinical practice and current evidence. CONCLUSIONS Pulmonary rehabilitation programs in Australia generally meet the broad recommendations for practice in terms of components, program length, assessment and exercise training. The prescription of exercise training intensity is an area requiring deeper exploration.

How prepared are rural and remote health care practitioners to provide evidence-based management for people with chronic lung disease?

OBJECTIVE To investigate the existing experience, training, confidence and knowledge of rural/remote health care practitioners in providing management for people with chronic obstructive pulmonary disease (COPD). DESIGN   Descriptive cross-sectional, observational survey design using a written anonymous questionnaire. This study formed part of a larger project evaluating the impact of breathe easy walk easy (BEWE), an interactive education and training program for rural and remote health care practitioners. SETTING Rural (n = 1, New South Wales) and remote (n = 1, Northern Territory) Australian health care services. PARTICIPANTS Health care practitioners who registered to attend the BEWE training program (n = 31). MAIN OUTCOME MEASURES Participant attitudes, objective knowledge and self-rated experience, training and confidence related to providing components of management for people with COPD. RESULTS Participants were from a variety of professional backgrounds (medical, nursing, allied health) but were predominantly nurses (n = 13) or physiotherapists (n = 9). Most participants reported that they had minimal or no experience or training in providing components of management for people with COPD. Confidence was also commonly rated by participants as low. Mean knowledge score (number of correct answers out of 19) was 8.5 (SD = 4.5). Questions relating to disease pathophysiology and diagnosis had higher correct response rates than those relating more specifically to pulmonary rehabilitation. CONCLUSION The results of this study indicate that some rural and remote health care practitioners have low levels of experience, knowledge and confidence related to providing components of management for people with COPD and that education and training with an emphasis on pulmonary rehabilitation would be beneficial.

Improving chronic lung disease management in rural and remote Australia: The Breathe Easy Walk Easy programme

Background and objective:  To evaluate the impact of a chronic lung disease management training programme, Breathe Easy Walk Easy (BEWE), for rural and remote health‐care practitioners.

Validation of respiratory inductive plethysmography (LifeShirt) in obesity hypoventilation syndrome.

Validation of respiratory inductive plethysmography (LifeShirt system) (RIPLS) for tidal volume (VT), minute ventilation (V˙E), and respiratory frequency (fB) was performed among people with untreated obesity hypoventilation syndrome (OHS) and controls. Measures were obtained simultaneously from RIPLS and a spirometer during two tests, and compared using Bland Altman analysis. Among 13 OHS participants (162 paired measures), RIPLS-spirometer agreement was unacceptable for VT: mean difference (MD) 3 mL (1%); limits of agreement (LOA) -216 to 220 mL (±36%); V˙E MD 0.1 L min(-1) (2%); LOA -4.1 to 4.3 L min(-1) (±36%); and fB: MD 0.2 br min(-1) (2%); LOA -4.6 to 5.0 br min(-1) (±27%). Among 13 controls (197 paired measures), RIPLS-spirometer agreement was acceptable for fB: MD -0.1 br min(-1) (-1%); LOA -1.2 to 1.1 br min(-1) (±12%), but unacceptable for VT: MD 5 mL (1%); LOA -160 to 169 mL (±20%) and V˙E: MD 0.1 L min(-1) (1%); LOA -1.4 to 1.5 L min(-1) (±20%). RIPLS produces valid measures of fB among controls but not OHS patients, and is not valid for quantifying respiratory volumes among either group.

Establishing and delivering pulmonary rehabilitation in rural and remote settings: The opinions, attitudes and concerns of health care professionals.

OBJECTIVE Pulmonary rehabilitation is recommended for people with chronic lung disease however access remains limited in rural and remote settings. The aim of this project was to explore the perspectives of rural and remote health care professionals regarding the establishment and delivery of pulmonary rehabilitation. SETTING Rural (NSW) and remote (NT) Australian healthcare settings. PARTICIPANTS Health care professionals (n = 25) who attended a training program focussing on the delivery of pulmonary rehabilitation. MAIN OUTCOME MEASURE(S) Surveys with open written questions were completed by participants following the training program. Key informants also participated in face-to-face interviews. Thematic analysis was undertaken of data collected on participant opinions, attitudes and concerns regarding the establishment and delivery of pulmonary rehabilitation in their individual situation. RESULTS Participating health care professionals (predominantly nurses and physiotherapists) identified a number of issues relating to establishing and delivering pulmonary rehabilitation; including staffing, time and case load constraints, patient and community attitudes, lack of professional knowledge and confidence and inability to ensure sustainability. The practicalities of delivering pulmonary rehabilitation, particularly exercise prescription and training, were also important concerns raised. CONCLUSIONS Lack of health care professional staffing, knowledge and confidence were reported to be factors impacting the establishment and delivery of pulmonary rehabilitation. This study has facilitated a greater understanding of the issues surrounding the establishment and delivery of pulmonary rehabilitation in rural and remote settings. Further research is required to investigate the contribution of health professional training and associated factors to improving the availability and delivery of pulmonary rehabilitation in rural and remote settings.

Validity of arterialised-venous PCO2, pH and bicarbonate in obesity hypoventilation syndrome

This prospective study investigated the validity of arterialised-venous blood gases (AVBG) for estimating arterial carbon dioxide P CO2, pH and bicarbonate (HCO3(-)) in people with obesity hypoventilation syndrome (OHS). AVBGs were obtained from an upper limb vein, after heating the skin at 42-46°C. Arterial blood gas (ABG) and AVBG samples were taken simultaneously and compared using Bland Altman analysis. Between-group differences were assessed with independent t-tests or Mann-Whitney U tests. Forty-two viable paired samples were analysed, including 27 paired samples from 15 OHS participants, and 15 paired samples from 16 controls. AVBG-ABG agreement was not different between groups, or between dorsal hand, forearm and antecubital AVBG sampling sites, and was clinically acceptable for P Co2: mean difference (MD) 0.4 mmHg (0.9%), limits of agreement (LOA) -2.7-3.6 mmHg (± 6.6%); pH: MD -0.008 (-0.1%), LOA -0.023-0.008 (± 0.2%); and HCO3(-): MD -0.3 mmol L(-1) (-1.0%), LOA -1.8-1.2 mmol L(-1) (± 5.3%). AVBG provides valid measures of [Formula: see text] , pH, and HCO3(-) in OHS.

Does Delivery of a Training Program for Healthcare Professionals Increase Access to Pulmonary Rehabilitation and Improve Outcomes for People with Chronic Lung Disease in Rural and Remote Australia

OBJECTIVE Access to pulmonary rehabilitation (PR), an effective management strategy for people with chronic respiratory disease, is often limited particularly in rural and remote regions. Difficulties with establishment and maintenance of PR have been reported. Reasons may include a lack of adequately trained staff. There have been no published reports evaluating the impact of training programs on PR provision. The aim of this project was to evaluate the impact of an interactive training and support program for healthcare professionals (the Breathe Easy, Walk Easy (BEWE) program) on the delivery of PR in rural and remote regions. METHODS The study was a quasi-experimental before-after design. Data were collected regarding the provision of PR services before and after delivery of the BEWE program and patient outcomes before and after PR. RESULTS The BEWE program was delivered in one rural and one remote region. Neither region had active PR before the BEWE program delivery. At 12-month follow-up, three locally-run PR programs had been established. Audit and patient outcomes indicated that the PR programs established broadly met Australian practice recommendations and were being delivered effectively. In both regions PR was established with strong healthcare organisational support but without significant external funding, relying instead on the diversion of internal funding and/or in-kind support. CONCLUSIONS The BEWE program enabled the successful establishment of PR and improved patient outcomes in rural and remote regions. However, given the funding models used, the sustainability of these programs in the long term is unknown. Further research into the factors contributing to the ability of rural and remote sites to provide ongoing delivery of PR is required.