Nocturnal ventilatory support in patients with cystic fibrosis: comparison with supplemental oxygen. Comparison of high-frequency chest wall oscillation and oscillating positive expiratory pressure in the home management of cystic fibrosis: a pilot study. Randomised placebo controlled trial of non-invasive ventilation for hypercapnia in cystic fibrosis. [Non-invasive ventilation in kyphoscoliosis. A comparison of a volumetric ventilator and a BIPAP support pressure device]. Evaluation of positive expiratory pressure as an adjunct to chest physiotherapy in the treatment of cystic fibrosis. Short-term comparative study of high frequency chest wall oscillation and European airway clearance techniques in patients with cystic fibrosis. Low-flow oxygen and bilevel ventilatory support: effects on ventilation during sleep in cystic fibrosis. Non-invasive ventilation assists chest physiotherapy in adults with acute exacerbations of cystic fibrosis. Chest physiotherapy with positive airway pressure: a pilot study of short-term effects on sputum clearance in patients with cystic fibrosis and severe airway obstruction.
Progressive deterioration of lung function in cystic fibrosis (CF) patients may lead to significant hypoxaemia and hypercapnia, especially during sleep. The effects of bi-level noninvasive positive pressure nasal mask ventilation (NIPPV) on respiration and sleep were compared to those of low-flow oxygen therapy in six CF patients (mean +/- SD age 22.3 +/- 4.7 yrs, with severe lung disease (forced expiratory volume in one second (FEV1) 29.4 +/- 3.4% predicted). Compared to the control night, NIPPV and oxygen therapy significantly improved overall night-time oxygen saturation during both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep stages. However, significant increases in transcutaneous CO2 tension occurred during oxygen therapy, while NIPPV markedly improved alveolar ventilation during all sleep states. Sleep architecture and arousals remained unchanged during NIPPV and oxygen therapy treatment nights. We conclude that noninvasive positive pressure ventilation improves sleep-related hypoxaemia and hypercapnia in severe cystic fibrosis patients without affecting sleep. The long-term compliance and benefits of noninvasive positive pressure ventilation remain unclear. Enhanced airway clearance is thought to result in better-maintained pulmonary function in cystic fibrosis (CF). Postural drainage, percussion, and vibration (PDPV) have been the primary airway clearance technique (ACT) employed in CF for over 40 years. Two new airway clearance modalities are high-frequency chest wall oscillation (HFCWO) and oscillating positive expiratory pressure (OPEP). This pilot study was undertaken to evaluate the efficacy of these techniques during home use, assess patient satisfaction with them as compared to PDPV, and assess the feasibility of performing a definitive comparative trial. The prospective, randomized, multicenter crossover trial was conducted at three urban academic CF Care Centers. Twenty-nine CF patients, 9-39 years of age, participated. Subjects performed 4 weeks each of HFCWO and OPEP following 2-week lead-in/washout periods. Spirometry, lung volumes, National Institutes of Health and Petty Scores, and a satisfaction survey were performed at baseline and after each treatment period. An ACT preference survey was completed at the conclusion of the study. Twenty-four subjects completed both therapies. There were no statistically significant differences between therapies for spirometry, lung volumes, or clinical scores. No significant safety issues arose during the study period. Compliance between therapies was similar. Significant differences among therapies existed in patient satisfaction. Given a choice of therapy, 50% of subjects chose HFCWO, 37% OPEP, and 13% PDPV. This study suggests that HFCWO and OPEP are safe and as effective as patients' routine therapies when used for airway clearance in a home setting. Patient satisfaction and preference differ among ACTs and should be considered when prescribing home therapy. A definitive, multi-center, comparative study evaluating long-term efficacy of these techniques is feasible.
                Copyright 2001 Wiley-Liss, Inc. The clinical benefits of domiciliary non-invasive positive pressure ventilation (NIV) have not been established in cystic fibrosis (CF). We studied the effects of nocturnal NIV on quality of life (QoL), functional and physiological outcomes in CF subjects with awake hypercapnia (arterial carbon dioxide pressure PaCO2>45 mm Hg).
                In a randomised, placebo controlled, crossover study, eight subjects with CF, mean (SD) age 37 (8) years, body mass index 21.1 (2.6) kg/m2, forced expiratory volume in 1 s 35 (8)% predicted and PaCO2 52 (4) mm Hg received 6 weeks of nocturnal (1) air (placebo), (2) oxygen and (3) NIV. The primary outcome measures were CF specific QoL, daytime sleepiness and exertional dyspnoea. Secondary outcome measures were awake and asleep gas exchange, sleep architecture, lung function and peak exercise capacity.
                Compared with air, NIV improved the chest symptom score in the CF QoL Questionnaire (mean difference 10; 95% CI 5 to 16; p = 0.002) and the transitional dyspnoea index score (mean difference 3.1; 95% CI 1.2-5.0; p = 0.01). It reduced maximum nocturnal pressure of transcutaneous CO2 (PtcCO2 mean difference -17 mm Hg; 95% CI -7 to -28 mm Hg; p = 0.005) and increased exercise performance on the Modified Shuttle Test (mean difference 83 m; 95% CI 21 to 144 m; p = 0.02). NIV did not improve sleep architecture, lung function or awake PaCO2.
                6 weeks of nocturnal NIV improves chest symptoms, exertional dyspnoea, nocturnal hypoventilation and peak exercise capacity in adult patients with stable CF with awake hypercapnia. Further studies are required to determine whether or not NIV can improve survival. Non-invasive intermittent positive pressure ventilation (NIPPV) at home is the treatment of choice for patients with chronic respiratory insufficiency secondary to severe kyphoscoliosis. Our aim was to compare clinical course, blood gases and lung function after one month of domiciliary NIPPV with two types of ventilator and to assess sleep pattern changes in patients enrolled in a prospective, randomized crossover study. Ten patients with chronic respiratory insufficiency due to kyphoscoliosis were enrolled and randomly assigned to the first device. After one month of use, the patients underwent clinical and functional examinations and polysomnographic studies while using the ventilator. The same protocol was applied with the second device after a ten-day washout period. Baseline polysomnographs showed fragmented sleep with low percentages of deep non-REM sleep and of REM sleep, as well as respiratory patterns characterized by very high frequencies coinciding with significant desaturations. In all cases symptoms and arterial blood gas improvements were significant, with no differences between the two treatment periods. The percentages of time spent with SaO2 below 90% of reference in sleep studies were significantly lower than baseline with both ventilators. All but one patient had better tolerance of the bilevel positive airway pressure (BIPAP) support mode than of the volumetric ventilator. Our study shows that NIPPV is equally effective for patients with kyphoscoliosis whether administered with a volumetric ventilator or a BIPAP device. Subjective response and tolerance seem to be slightly better with BIPAP. It has been suggested that positive expiratory pressure may assist the clearance of bronchial secretions in the treatment of cystic fibrosis. It has been compared with currently used postural drainage techniques. Three treatment regimens were compared in 18 patients with cystic fibrosis. Treatment A consisted of breathing exercises emphasising inspiration, interspersed with the forced expiration technique in gravity assisted positions; treatment B comprised breathing exercises with positive expiratory pressure alternating with the forced expiration technique in the same gravity assisted positions; and treatment C comprised breathing exercises with positive expiratory pressure and the forced expiration technique in the sitting position. During treatment A a significantly greater quantity of sputum was produced than during treatments B and C (p less than 0.025 and p less than 0.001 respectively). Treatment B produced more sputum than treatment C (p less than 0.005). There were no significant differences in arterial oxygen saturation, FEV1 or forced vital capacity. Most adolescent and adult patients are able to carry out their treatment independently using gravity assisted positions, breathing exercises emphasising inspiration, and the forced expiration technique. Sputum clearance was less effective when positive expiratory pressure was included in the treatment regimen. High frequency chest wall oscillation (HFCWO) is standard treatment for airway clearance in the USA and has recently been introduced in the UK and Europe. There is little published research comparing HFCWO with airway clearance techniques (ACTs) frequently used in the UK and Europe. The aim of this study was to compare the short-term effects of HFCWO with usual ACTs in patients with cystic fibrosis hospitalised with an infective pulmonary exacerbation.
                A 4-day randomised crossover design was used. Patients received either HFCWO on days 1 and 3 and usual ACTs on days 2 and 4 or vice versa. Wet weight of sputum, spirometry and oxygen saturation were measured. Perceived efficacy, comfort, incidence of urinary leakage and preference were assessed. Data were analysed by mixed model analysis.
                29 patients (72% male) of mean (SD) age 29.4 (8.4) years and mean (SD) forced expiratory volume in 1 s (FEV(1)) percentage predicted (FEV(1)%) 38 (16.7) completed the study. Significantly more sputum was expectorated during a single treatment session and over a 24 h period (mean difference 4.4 g and 6.9 g, respectively) with usual ACTs than with HFCWO (p<0.001). No statistically significant change in FEV(1)% or oxygen saturation was observed after either HFCWO or usual ACTs compared with baseline. 17 patients (55%) expressed a preference for their usual ACT.
                During both a finite treatment period and over 24 h, less sputum was cleared using HFCWO than usual ACT. HFCWO does not appear to cause any adverse physiological effects and may influence adherence. We measured ventilation in all sleep stages in patients with cystic fibrosis (CF) and moderate to severe lung disease, and compared the effects of low-flow oxygen (LFO2) and bilevel ventilatory support (BVS) on ventilation and gas exchange during sleep. Thirteen subjects, age 26 +/- 5.9 yr (mean +/- 1 SD), body mass index (BMI) 20 +/- 3 kg/m2, FEV1 32 +/- 11% predicted, underwent three sleep studies breathing, in random order, room air (RA), LFO2, and BVS +/- O2 with recording of oxyhemoglobin saturation (SpO2) (%) and transcutaneous carbon dioxide (TcCO2) (mm Hg). During RA and LFO2 studies, patients wore a nasal mask with a baseline continuous positive airway pressure (CPAP) of 4 to 5 cm H2O. Minute ventilation (V I) was measured using a pneumotachograph in the circuit and was not different between wake and non-rapid eye movement (NREM) sleep on any night. However, V I was reduced on the RA and LFO2 nights from awake to rapid eye movement (REM) (p < 0.01) and from NREM to REM (p < 0.01). On the BVS night there was no significant difference in V I between NREM and REM sleep. Both BVS and LFO2 improved nocturnal SpO2, especially during REM sleep (p < 0.05). The rise in TcCO2 seen with REM sleep with both RA and LFO2 was attenuated with BVS (p < 0.05). We conclude that BVS leads to improvements in alveolar ventilation during sleep in this patient group. Chest physiotherapy is essential to the management of cystic fibrosis (CF). However, respiratory muscle fatigue and oxygen desaturation during treatment have been reported. The aim of this study was to determine whether non-invasive ventilation (NIV) during chest physiotherapy could prevent these adverse effects in adults with exacerbations of CF.
                Twenty six patients of mean (SD) age 27 (6) years and forced expiratory volume in 1 second (FEV1) 34 (12)% predicted completed a randomised crossover trial comparing standard treatment (active cycle of breathing technique, ACBT) with ACBT + NIV. Respiratory muscle strength (PImax, PEmax), spirometric parameters, and dyspnoea were measured before and after treatment. Pulse oximetry (SpO2) was recorded during treatment. Sputum production during treatment and 4 and 24 hours after treatment was evaluated.
                There was a significant reduction in PImax following standard treatment that was correlated with baseline PImax (r=0.73, p<0.001). PImax was maintained following NIV (mean difference from standard treatment 9.04 cm H2O, 95% confidence interval (CI) 4.25 to 13.83 cm H2O, p=0.006). A significant increase in PEmax was observed following the NIV session (8.04 cm H2O, 95% CI 0.61 to 15.46 cm H2O, p=0.02). The proportion of treatment time with SpO2 < or =90% was correlated with FEV1 (r=-0.65, p<0.001). NIV improved mean SpO2 (p<0.001) and reduced dyspnoea (p=0.02). There were no differences in FEV1, forced vital capacity (FVC) or sputum weight, but FEF(25-75) increased following NIV (p=0.006).
                Reduced inspiratory muscle strength and oxygen desaturation during chest physiotherapy are associated with inspiratory muscle weakness and severity of lung disease in adults with exacerbations of CF. Addition of NIV improves inspiratory muscle function, oxygen saturation and small airway function and reduces dyspnoea. The periodic administration of positive airway pressure combined with directed cough could aid mucus clearance in patients with cystic fibrosis (CF) and severe airway obstruction.
                To compare the short-term effect of positive expiratory pressure (PEP) physiotherapy via mask (mask PEP), continuous positive airway pressure (CPAP), and noninvasive positive-pressure ventilation (NPPV) physiotherapies on amount of sputum collected.
                Directed cough was standardized for each patient and used as the control treatment. We studied 17 patients with CF (mean +/- SD age 28 +/- 7 y) and severe airway obstruction (forced expiratory volume in the first second 25 +/- 6% of predicted) admitted for pulmonary exacerbation. Mask PEP, CPAP, NPPV, and the control treatment (directed cough) were administered in a random sequence. Each patient received each treatment twice a day (in 70-min sessions) for 2 consecutive days. We measured the wet and dry weight of sputum collected and the number of directed and spontaneous coughs during each session. Spirometry and pulse oximetry were conducted before and after each session. For mask PEP, CPAP, and NPPV, each patient gave a subjective score for the efficacy and tolerability of the treatment, compared to the control treatment.
                There was no statistically significant difference in the dry weight of sputum collected: mask PEP 0.9 +/- 0.6 g, CPAP 0.8 +/- 0.4 g, NPPV 0.9 +/- 0.6 g, control treatment 1.0 +/- 0.8 g. There was a statistically significant difference in the wet weight of sputum collected: mask PEP 15.8 +/- 5.5 g, CPAP 13.7 +/- 5.5 g, NPPV 13.2 +/- 5.0 g, control treatment 14.0 +/- 5.0 g (p < 0.05), but that difference became nonsignificant when we took into account the number of spontaneous coughs. There were no statistically significant changes in the spirometry and pulse-oximetry values. The patients' subjective efficacy scores were similar for mask PEP, CPAP, and NPPV. Less fatigue was reported after NPPV and CPAP than after mask PEP.
                There were no differences in sputum clearance or pulmonary-function measures between mask PEP and short-term administration of either CPAP or NPPV combined with directed cough. After mask PEP these patients felt more tired than after CPAP or NPPV secretion-clearance therapy.
Non-invasive ventilation may be a useful adjunct to other airway clearance techniques, particularly in people with cystic fibrosis who have difficulty expectorating sputum. Non-invasive ventilation, used in addition to oxygen, may improve gas exchange during sleep to a greater extent than oxygen therapy alone in moderate to severe disease. These benefits of non-invasive ventilation have largely been demonstrated in single treatment sessions with small numbers of participants. The impact of this therapy on pulmonary exacerbations and disease progression remain unclear. There is a need for long-term randomised controlled trials which are adequately powered to determine the clinical effects of non-invasive ventilation in cystic fibrosis airway clearance and exercise.