Nocturnal Nasal Intermittent Positive Pressure Research Articles

Treatment of chronic respiratory failure in kyphoscoliosis: oxygen or ventilation?

Patients with kyposcoliosis and chronic respiratory insufficiency are treated either with home oxygen therapy or ventilation. Kyphoscoliotic patients demonstrate impaired ventilatory mechanics, consequently ventilation seems to be the treatment of choice. Yet, no randomised controlled trials (CRT) exist to prove it. Most investigators find it difficult to ethically justify a CRT. Therefore, the current authors performed the following retrospective study: survival and pulmonary function were analysed in all consecutive kyphoscoliotic patients who started long-term oxygen therapy (LTO group; n=15, aged 62+/-11 yrs (mean+/-SD)) or LTO plus nocturnal nasal intermittent positive pressure ventilation (nNIPPV group; n=18, aged 61+/-7 yrs) in the Dept of Pulmonology (University Hospital Gasthuisberg, Leuven) between 1990-2002. Prior to treatment partial pressure of oxygen (PO2) was lower, partial pressure of carbon dioxide (PCO2) tended to be higher and vital capacity (VC) tended to be lower in the nNIPPV group than in the LTO group (PO2 5.9+/-1 versus 6.7+/-0.9 kPa (44+/-8 versus 50+/-7 mmHg), PCO2 8+/-1 versus 7.3+/-0.9 kPa (60+/-8 versus 55+/-7 mmHg), VC 32+/-12 versus 40+/-16% predicted, or 645+/-244 versus 970+/-387 mL). In the nNIPPV group the 1-yr survival was higher (100% versus 66%). nNIPPV patients demonstrated an improvement in PO2 (breathing air) +54%, PCO2 (breathing air) -21%, VC +47% and maximal static inspiratory mouth pressure +33%; these improvements were absent in the LTO group. In conclusion, nocturnal nasal intermittent positive pressure ventilation, plus long-term oxygen therapy results in more favourable survival and changes in blood gases and respiratory function than long-term oxygen therapy alone.

Ventilatory response to CO2re-breathing before and after Nocturnal Nasal Intermittent Positive Pressure Ventilation in patients with chronic alveolar hypoventilation

Long-term nocturnal nasal intermittent positive pressure ventilation (NIPPV) has beneficial effects on daytime P a CO2in patients with chronic alveolar hypoventilation. Our aim was to investigate if these beneficial effects are related to improved respiratory drive as measured by ventilatory response to CO2.In 17 hypoventilated patients (mean age 62 years) we obtained daytime arterial blood gases, nocturnal transcutaneous oxygen saturation, nocturnal transcutaneous PaCO2,ventilatory response to CO2re-breathing, spirometry and indices of respiratory muscle strength before and after 9 months of NIPPV. Patients served as their own controls.After 9 months of NIPPV day-time P a CO2decreased from 7·1 kPa to 6·3 kPa, (P<0·001) and P a O2increased from 8·1 kPa to 9·3 kPa, (P<0·01). The changes in morning and daytime P a CO2and in nocturnal transcutaneous oxygen saturation were significantly correlated to the changes in several variables derived from the ventilatory response to CO2re-breathing. In patients with substantial improvement in daytime P a CO2we found significant improvements in ventilatory response to CO2re-breathing.The present study confirms the beneficial effect of long-term NIPPV on daytime arterial blood gases. The results are consistent with the hypothesis that the improvement of daytime P a CO2is related to improved respiratory drive observed after NIPPV.

Long-term nasal intermittent positive pressure ventilation (NIPPV) in sixteen consecutive patients with bronchiectasis: a retrospective study.

Life expectancy and quality of life are poor in patients with chronic respiratory failure due to bronchiectasis. The indication for nocturnal nasal intermittent positive pressure ventilation (NIPPV) remains controversial in chronic obstructive lung disease. The purpose of the present study was to determine whether some of the objectives of home mechanical ventilation, i.e. improvement in blood gas values and reduced length of hospitalization, were fulfilled by NIPPV and oxygen plus medical treatment in patients with chronic respiratory failure due to bronchiectasis. Sixteen consecutive patients (12 females and four males; mean age 57 +/- 11 yrs) with chronic respiratory failure due to bronchiectasis, treated at home with nocturnal NIPPV in addition to oxygen therapy, were retrospectively studied in terms of blood gas values and duration of hospitalization before and after NIPPV. Details of the therapy received by each patient were recorded. Nine patients agreed to complete a questionnaire to determine their perception of the benefits of the treatment. NIPPV was performed using a volumetric respirator and was applied with a customized nasal mask modelled with silicone paste. NIPPV was used for a mean of 26 months (range 0.5-60 months). Eleven patients were alive 12 months after use of NIPPV. No significant improvement in blood gas values was noted on room air during NIPPV, but arterial carbon dioxide tension (Pa,CO2) stabilized after the period of worsening observed before initiation of NIPPV. Duration of hospitalization, the year before and the year after NIPPV, was 19 (3-40) and 16 (8-37) days, respectively (NS). For the 11 patients who were alive 2 yrs after the start of NIPPV, duration of hospitalization the year before NIPPV and between 12 and 24 months after NIPPV were 17 (4-40) and 7 (2-27) days, respectively (p < 0.05). Nine patients who had received NIPPV for at least 12 months at the time of the study reported an improvement in their quality of life. The results suggest that home ventilatory support by nasal intermittent positive pressure ventilation offers an acceptable alternative to tracheotomy, with less discomfort, in the management of severe respiratory failure due to bronchiectasis, in order to allow the patient to return home. These results should be confirmed by controlled studies.

Effects of long-term nocturnal nasal ventilation on spontaneous breathing during sleep in neuromuscular and chest wall disorders.

Nocturnal nasal intermittent positive pressure ventilation (NIPPV) is an effective means of normalizing awake blood gases in patients with respiratory insufficiency due to neuromuscular or chest wall dysfunction. However, little attention has been paid to the effects of long-term ventilation on spontaneous breathing during sleep in such patients. The purpose of this study was to determine whether spontaneous breathing during sleep improved after long-term nasal ventilation. Fourteen patients with documented nocturnal respiratory failure, who had been treated with nocturnal NIPPV for at least 6 months, were reviewed with an all night polysomnograph on a night without ventilatory support. The severity of nocturnal desaturation both in non-rapid eye movement (NREM) and rapid eye movement (REM) sleep without nocturnal ventilation was compared to desaturation measured during the initial diagnostic study. Spontaneous daytime blood gas values (mean +/- SD) were significantly improved at follow-up compared to values obtained prior to nasal ventilation: arterial oxygen tension (Pa,O2): 7.5 +/- 1.2 to 10.2 +/- 1.3 kPa (p < 0.005); arterial carbon dioxide tension (Pa,CO2) 8.2 +/- 1.6 to 6.4 +/- 0.7 kPa (p < 0.001). Significant improvements in inspiratory muscle strength were also observed with maximal inspiratory pressure (Pl, max) increasing from a baseline value of 41 +/- 18 to 65 +/- 26% predicted measured prior to the night of ventilation withdrawal (p < 0.003). Spontaneous breathing during sleep after long-term treatment was markedly improved although still abnormal. During NREM sleep without ventilatory support, oxygen desaturation was significantly less severe compared to the initial study (arterial oxygen saturation (Sa,O2) 88 +/- 4 vs 78 +/- 8%; p < 0.001). Minimum Sa,O2 during REM sleep similarly improved from a mean value of 49 +/- 14% during the diagnostic night to 73 +/- 10% at review follow-up (p < 0.001). In 12 patients, transcutaneous carbon dioxide was measured continuously during sleep on both occasions and demonstrated significantly less CO2 retention during follow-up compared to control studies both in NREM (p < 0.003) and REM sleep states (p < 0.004). Long-term nocturnal ventilation produces improved respiratory drive both asleep and awake and improved arousal responses to abnormal blood gases.

Nocturnal Nasal IPPV Stabilizes Patients with Cystic Fibrosis and Hypercapnic Respiratory Failure

Nocturnal nasal intermittent positive pressure ventilation (nIPPV) has been used successfully in the management of patients with respiratory failure due to chest wall deformity and neuromuscular disease. In order to determine if nIPPV is useful in patients with cystic fibrosis (CF) complicated by respiratory failure, we treated four hypercapnic patients for up to 18 months. All patients had failed to respond to intensive conventional therapy, including nocturnal nasal CPAP in three of the patients. Within a few days of commencing nIPPV, all reported improved length and quality of sleep. There was lessening of the degree of hypercapnia and an increase in respiratory muscle strength. After stabilization in the hospital, all patients were able to be discharged home receiving nocturnal assisted ventilation. The improvements seen in these patients have been maintained for up to 18 months. We believe nIPPV offers an effective therapeutic approach for patients with end-stage CF in hypercapnic respiratory failure and may be particularly advantageous for those awaiting heart-lung transplant.

Domiciliary nocturnal nasal intermittent positive pressure ventilation in hypercapnic respiratory failure due to chronic obstructive lung disease: effects on sleep and quality of life.

Domiciliary assisted ventilation, using negative or positive pressure devices, is an effective treatment for respiratory failure due to chest wall deformity and neuromuscular disease. Negative pressure ventilators have been used with some success in patients with chronic obstructive lung disease in hospital, but attempts to continue treatment at home have been disappointing. This study evaluates the practicalities of nasal intermittent positive pressure ventilation at home in patients with chronic obstructive lung disease and the effect on sleep and quality of life. Twelve patients with chronic obstructive lung disease and hypercapnic respiratory failure received nasal intermittent positive pressure ventilation at home during sleep. At six months eight were continuing with the ventilation. One patient had died and three had withdrawn because they were unable to sleep with the equipment. Full polysomnography performed during ventilation in patients continuing treatment at six months showed an increase in mean PaO2 of 11% (+2% to +23%) and lower mean transcutaneous carbon dioxide tensions (by -2.7 (-1.3 to -5.1) kPa) overnight compared with spontaneous breathing before the start of nasal intermittent positive pressure ventilation. Total sleep time and sleep efficiency changed during ventilation by +72.5 (+21 to +204) minutes and +5% (-3% to +30%) respectively; sleep architecture and the number of arousals were unchanged. Quality of life did not change but was no worse during ventilation. At one year seven patients were still using the ventilator and PaCO2 and bicarbonate ion concentration during the day had improved further by comparison with the values at six months (change from baseline -1.7 (-2.1 to -0.6) kPa, p less than 0.05, and -6.3 (-11.9 to -4) mmol/l, p less than 0.05). Nasal intermittent positive pressure ventilation can be used effectively at home during sleep in selected patients with chronic obstructive lung disease. Its future place in management can be established only by formal comparison with long term oxygen therapy.

Nocturnal Nasal Intermittent Positive Pressure Ventilation with Bi-level Positive Airway Pressure (BiPAP) in Respiratory Failure

The purpose of this study was to assess the efficacy of bi-level positive airway pressure (BiPAP) ventilation through a nasal mask in the treatment of eight patients with hypoventilatory respiratory failure and nocturnal CO2 retention. Nocturnal CO2 retention was significantly reduced in all patients with the application of BiPAP during sleep (p less than 0.01). Daytime somnolence was relieved and dyspnea improved after three months of home BiPAP therapy. All patients tolerated home BiPAP therapy, and two patients who had previously been treated with volume ventilation via nasal mask found BiPAP more comfortable. There were no changes in FEV1 or FVC after three months of BiPAP. Daytime PaCO2 improved slightly or remained stable in all patients after three months of home BiPAP. BiPAP nasal ventilation is effective in reducing nocturnal CO2 retention short term in hypoventilatory respiratory failure due to obesity hypoventilation syndrome, chest wall restriction, or neuromuscular disease. Further studies in patients with COPD may be warranted.

Domiciliary nocturnal nasal intermittent positive pressure ventilation in COPD: mechanisms underlying changes in arterial blood gas tensions

The improvement in arterial blood gas tensions following assisted ventilation in chronic obstructive pulmonary disease (COPD) has usually been attributed to the relief of incipient or established respiratory muscle fatigue. The contribution of changes in the load placed upon and the drive to the respiratory muscle pump have not been evaluated. We have investigated the contribution of changes in respiratory muscle strength, the ventilatory response to CO2 and ventilatory function to changes in arterial blood gas tensions in eight patients with severe COPD completing six months domiciliary nasal intermittent positive pressure ventilation. Six patients showed a reduction and two an increase in arterial carbon dioxide tension (PaCO2), median (range) for eight patients, -0.9 kPa (-1.5 to +0.4) (p less than 0.05) and seven showed an improvement in arterial oxygen tension (PaO2), +0.7 kPa (-0.4 to +1.7) (p less than 0.05) during daytime spontaneous breathing. The reduction in PaCO2 was not related to increased inspiratory muscle strength but was correlated with a decrease in gas trapping (Spearman rank correlation coefficient (r(S)) 0.85, p less than 0.05) and in the residual volume (r(s) 0.78, p less than 0.05), suggesting reduced small airway obstruction and, therefore, a reduction in load. The change in PaCO2 also correlated with the increase in ventilation at an end-tidal CO2 of 8 kPa during rebreathing (r(s) -0.76, p less than 0.05) suggesting improved chemosensitivity to CO2. Our data do not support the hypothesis that improvements were due to the relief of muscle fatigue. We suggest that the contribution of changes in load and central drive warrant further investigation.

Occult respiratory failure as a cause of neuropsychiatric symptoms in chest wall deformity and neuromuscular disease

Nocturnal hypoventilation occurs in patients with severe kyphoscoliosis (1) and neuromuscular disorders (2,3) and may lead to the development of daytime symptoms and cardio-respiratory failure. The onset is generally insidious and delay in diagnosis common. We report three patients presenting with primarily neuropsychiatric symptoms, in whom an underlying respiratory abnormality was not immediately apparent. All were returned to normal health by domiciliary nocturnal nasal intermittent-positive pressure ventilation (NIPPV).

Management of Chronic Alveolar Hypoventilation by Nasal Ventilation

This is a study of the effect of nocturnal nasal intermittent positive pressure ventilation (NIPPV) on symptoms of chronic alveolar hypoventilation (CAH), sleep oxygen saturation (SaO2), and frequency of hospitalization of patients with progressive neuromuscular respiratory insufficiency or restrictive lung disease from thoracic wall deformity. The nocturnal use of NIPPV is explored in combination with other noninvasive methods of supported ventilation for daytime support as alternatives to tracheostomy and long-term tracheostomy intermittent positive pressure ventilation (TIPPV). Sixteen patients with less than 400 ml of vital capacity (VC) supine and less than 15 minutes of autonomous respiration (free time) maintained a mean SaO2 of 95.9 +/- 2.6 percent (SD) during sleep on NIPPV without added oxygen. Seventeen other patients with adequate free time for a sleep trial unaided had an average SaO2 of 81.8 +/- 11.0 percent which improved to 94.1 +/- 3.4 percent on NIPPV alone. The average length of use of NIPPV by the 42 patients who have used it for one month or more is 21 (3-67) months. All 34 patients who were not dependent on ventilatory support 24 hours a day demonstrated significant improvement and in most cases normalization of ABG when off aid. Thirteen patients were converted from IPPV via an endotracheal tube or TIPPV to NIPPV. Long-term use of a custom molded thermoplastic nasal interface for the delivery of NIPPV is reported for 17 patients. Unnecessary morbidity and hospitalizations can be avoided by early awareness and appropriate management of CAH. NIPPV can be an effective alternative to TIPPV, body ventilators, or oxygen therapy.