Israel Medical Association Journal

Objectives: To minimize ventilatory limitation during training of patients with severe COPD[1] by applying bi-level positive pressure ventilation during training in order to augment training intensity (and effect).

Methods: The study group comprised 19 patients (18 males, 1 female) with a mean age of 64 ± 9 years. Mean forced expiratory volume in 1 second was 32 ± 4% of predicted, and all were ventilatory-limited (exercise breathing reserve 3 ± 9 L/min, normal >15 L/min). The patients were randomized: 9 were assigned to training with BiPAP[2] and 10 to standard training. All were trained on a treadmill for 2 months, twice a week, 45 minutes each time, at maximal tolerated load. Incremental maximal unsupported exercise test was performed before and at the end of the training period.

Results: BiPAP resulted in an increment of 94 ± 53% in training speed during these 2 months, as compared to 41 ± 19% increment in the control group (P < 0.005). Training with BiPAP yielded an average increase in maximal oxygen uptake of 23 ± 16% (P < 0.005), anaerobic threshold of 11 ± 12% (P < 0.05) and peak O₂ pulse of 20 ± 19% (P < 0.05), while peak exercise lactate concentration was not higher after training. Interestingly, in the BiPAP group, peak exercise ventilation was also 17 ± 20% higher after training (P < 0.05). Furthermore, contrary to our expectation, at any given work rate, ventilation (and tidal volume) in the BiPAP group was higher in the post-training test as compared to the pre-training test, and the end tidal partial pressure of CO₂ at 55 watts was lower, 40 ± 4 and 38 ± 4 mmHg respectively (P < 0.05). No improvement in exercise capacity was observed after this short training period in the control group.

Conclusion: Pressure-supported ventilation during training is feasible in patients with severe COPD and it augments the training effect. The improved exercise tolerance was associated with higher ventilatory response and therefore lower P_ETCO₂[3] at equal work rates after training.

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[1] COPD = chronic obstructive pulmonary disease

[2] BiPAP = bi-level positive pressure ventilation

[3] P_ETCO₂ = end tidal partial pressure of CO₂
 

Background: Continuous positive airway pressure is the treatment of choice for patients with obstructive sleep apnea syndrome.

Objective: To determine the factors influencing treatment initiation with a CPAP[1] device in a healthcare system in which co-payment is required.

Methods: A total of 400 adult patients with OSAS[2] who required CPAP therapy completed questionnaires at three different stages of the diagnostic and therapeutic process: CPAP titration study (stage 1), patient adaptation trial (stage 2), and purchase of a CPAP device (stage 3). Logistic regression was used to analyze the variables influencing CPAP use at the different stages of the diagnostic and therapeutic processes.

Results: Only 32% of the patients who underwent CPAP titration study purchased a CPAP device. The number of subjects who purchased a CPAP device increased gradually as monthly income increased, 28% vs. 62% in the “very low” and “very high” income levels respectively. Reporting for the titration increased in patients with excessive daytime sleepiness and an Epworth Sleepiness Scale score above 9 (odds ratio = 1.9, P = 0.015). Higher socioeconomic status increased reporting to stage 2 (OR[3] = 1.23, P = 0.03) and CPAP purchase (stage 3, OR = 1.35, P = 0.002). Excessive daytime sleepiness increased reporting to stage 2 (OR = 2.28, P = 0.006). Respiratory disturbance index above 35 increased CPAP purchasing (OR = 2.01, P = 0.022). Support from the bed partner, referring physician and sleep laboratory team increased CPAP purchasing.

Conclusions: A supportive environment for a patient with OSAS requiring CPAP is crucial to increase initiation of CPAP treatment. Minimizing cost sharing for the CPAP device will reduce inequality and may increase CPAP treatment initiation.

Background: Pulmonary disease is the most frequent cause of morbidity and mortality in cystc fibrosis patients. New techniques such as non-invasive positive pressure ventilation have resulted in prolongation of life expectancy in CF[1] patients with end-stage lung disease.

Objectives: To determine the role of NIPPV[2] in CF patients awaiting lung transplantation.

Methods: Between 1996 and 2001 nine CF patients (5 females) with end-stage lung disease were treated with bi-level positive airway pressure ventilation in the "spontaneous" mode.

Results: The patients' mean age at initiation of BiPAP[3] was 15 years (range 13–40 years) and the mean duration of BiPAP usage was 8 months (range 3–16 months). Four patients underwent successful lung transplantation, three patients died while awaiting transplantation, and the remaining two are still on NIPPV while waiting for transplantation. Patients' body mass index increased significantly (P < 0.05) during BiPAP therapy (from 16.1 to 17.2 kg/m²). Blood pH, p_aCO₂, and bicarbonate improved significantly (from 7.31 to 7.38, 90.8 to 67.2 mmHg, and 48.9 to 40.3 mEq/L, respectively). Pulmonary function tests were not affected by BiPAP usage. The patients experienced a significant alleviation in morning headaches and improvement in quality of sleep (P < 0.003). There were no major complications during BiPAP usage.

Conclusions: We demonstrated that long-term NIPPV can stabilize and improve physiologic parameters such as ventilation, arterial blood gases and body mass index, as well as subjective symptoms such as sleep pattern, daily activity level, and morning headaches in CF patients with end-stage lung disease. Further prospectively controlled studies are needed to evaluate the potential of BiPAP therapy and its influence on morbidity and mortality in the post-lung transplantation period.