Fiber-optic bronchoscopy and volume-cycled mouthpiece ventilation for a patient with multiple sclerosis and ventilatory failure.

Fiber-optic bronchoscopy supported by continuous or bilevel positive airway pressure has helped patients with hypoxemic or hypercapnic respiratory failure avoid respiratory complications. The authors describe a case of a 57-yr-old man with multiple sclerosis with a vital capacity of 250 ml (5% of predicted normal) who was using continuous noninvasive intermittent positive pressure ventilatory support when he underwent bronchoscopy while receiving continuous noninvasive intermittent positive pressure ventilatory support via a 15-mm angled mouthpiece interface. He was switched from a nasal to a 15-mm angled mouthpiece interface for continuous noninvasive intermittent positive pressure ventilatory support for the procedure. Simple mouthpieces may be useful alternatives to other facial interfaces for ventilatory support during bronchoscopy because of patient comfort and operator convenience.

Evaluation of manual and automatic manually triggered ventilation performance and ergonomics using a simulation model.

BACKGROUND: In the absence of endotracheal intubation, the manual bag-valve-mask (BVM) is the most frequently used ventilation technique during resuscitation. The efficiency of other devices has been poorly studied. The bench-test study described here was designed to evaluate the effectiveness of an automatic, manually triggered system, and to compare it with manual BVM ventilation. METHODS: A respiratory system bench model was assembled using a lung simulator connected to a manikin to simulate a patient with unprotected airways. Fifty health-care providers from different professional groups (emergency physicians, residents, advanced paramedics, nurses, and paramedics; n = 10 per group) evaluated manual BVM ventilation, and compared it with an automatic manually triggered device (EasyCPR). Three pathological situations were simulated (restrictive, obstructive, normal). Standard ventilation parameters were recorded; the ergonomics of the system were assessed by the health-care professionals using a standard numerical scale once the recordings were completed. RESULTS: The tidal volume fell within the standard range (400-600 mL) for 25.6% of breaths (0.6-45 breaths) using manual BVM ventilation, and for 28.6% of breaths (0.3-80 breaths) using the automatic manually triggered device (EasyCPR) (P < .0002). Peak inspiratory airway pressure was lower using the automatic manually triggered device (EasyCPR) (10.6 ± 5 vs 15.9 ± 10 cm H2O, P < .001). The ventilation rate fell consistently within the guidelines, in the case of the automatic manually triggered device (EasyCPR) only (10.3 ± 2 vs 17.6 ± 6, P < .001). Significant pulmonary overdistention was observed when using the manual BVM device during the normal and obstructive sequences. The nurses and paramedics considered the ergonomics of the automatic manually triggered device (EasyCPR) to be better than those of the manual device. CONCLUSIONS: The use of an automatic manually triggered device may improve ventilation efficiency and decrease the risk of pulmonary overdistention, while decreasing the ventilation rate.

Comparison of Alpha 200 and CoughAssist as intermittent positive pressure breathing devices: a bench study.

BACKGROUND: Intermittent positive pressure breathing (IPPB) is used in non-intubated patients to increase lung volume and to enhance coughing. Alpha 200 (Salvia Lifetec, Kronberg, Germany) is a specific IPPB device. CoughAssist (Respironics France, Carquefou, France) is a mechanical insufflator-exsufflator used to remove secretions in patients with inefficient cough. Both can also be used for intubated or tracheotomized patients. We assessed the impact of various artificial airways on the ability of the Alpha 200 and CoughAssist to generate insufflated volume. METHODS: We measured the insufflated volume and pressure at the airway opening in a lung model under 2 conditions of compliance (30 or 60 mL/cm H(2)O) at single resistance of 5 cm H(2)O/L/s. The devices were used at 2 set pressures: 30 and 40 cm H(2)O. The Alpha 200 was set at 2 inflation flows: 0.5 and 1 L/s, whereas CoughAssist was set at its highest value of 10 L/s. Measurements were done without (control) and with different size endotracheal tubes and tracheostomy cannulae. The relationships between insufflated volume and measured pressure were analyzed using linear regressions. RESULTS: The slopes and intercepts of the control relationship between insufflated volume and pressure were significantly greater with Alpha 200 at each set flow than with CoughAssist. As artificial airways were used, the insufflated volume did not differ from the control with CoughAssist, while with Alpha 200 it increased at each flow setting and for all mechanical conditions. The largest differences in insufflated volume between the 2 devices were observed for the largest endotracheal tubes and tracheostomy cannulas and for the lowest inflation flow setting in Alpha 200. These results can be explained in terms of how the devices function, as CoughAssist adapts by increasing flow, while Alpha 200 adapts by increasing inspiratory time. CONCLUSIONS: This bench study has shown that in the presence of artificial airways the value of the insufflated volume generated by the CoughAssist device was significantly lower than that generated by the Alpha 200 device.

Evaluation of the inspiratory pressure using a digital vacuometer in mechanically ventilated patients: analysis of the time to achieve the inspiratory peak.

BACKGROUND: The measurement of the maximal inspiratory pressure (P(Imax)) is of great importance in choosing the time for the start of weaning. OBJECTIVE: To measure the inspiratory pressure in mechanically ventilated patients suitable for weaning to determine the point at which the P(Imax) is achieved within 60 seconds of observation, and analyze factors associated with P(Imax) values. METHODS: Measurement of P(Imax) was accomplished with a digital vacuometer with a unidirectional valve, which allows only exhalation (P(ImaxUV)). With this technique, values are registered and stored, remaining accessible whenever necessary. All patients were on mechanical ventilation, and met the criteria recommended by the American Thoracic Society/European Respiratory Society in 2007 to undergo weaning trial. RESULTS: Eighty-four from the 87 enrolled patients completed the test. No patients reached the P(ImaxUV) in the first 20 seconds of observation. P(ImaxUV) was achieved between 20.1 and 40 seconds in 12 patients (14.0%), and between 40.1 and 60 seconds in 72 cases (86.0%). In a multivariate analysis model in which age, sex, days of mechanical ventilation, APACHE score, and respiratory drive (measured as airway-occlusion pressure 0.1 s after the start of inspiratory flow [P(0.1)]) were included, only age (P = .006) and P(0.1) (P = .003) were significantly associated with the values of P(ImaxUV). CONCLUSIONS: Within an observation period of 60 seconds, the majority of patients reached the maximal inspiratory peak between 40.1 and 60 seconds. Older patients were found to have lower P(ImaxUV) values, whereas higher values for P(0.1) strongly correlated with higher P(ImaxUV) values. These findings are potentially useful to improve successful weaning prediction in the future, but further studies are needed to better clarify this issue.

Prolonging survival in amyotrophic lateral sclerosis: efficacy of noninvasive ventilation and uncuffed tracheostomy tubes.

OBJECTIVE: To assess the efficacy of noninvasive ventilatory support and intermittent positive pressure ventilation via uncuffed tracheostomy tubes (uTIPPV) to prolong survival in amyotrophic lateral sclerosis. DESIGN: Survival was prolonged by continuous noninvasive ventilatory support or TIPPV dependence. Once noninvasive ventilatory support was no longer adequate for six noninvasive ventilatory support users, they and 22 others underwent tracheotomy within 1 mo of measurement of spirometry (forced vital capacity and forced volume expired in 1 sec), peak cough flows, maximum insufflation capacity, manually assisted peak cough flows, and mechanically assisted peak cough flows. Glottic function was estimated by maximum insufflation capacity, FVC difference, and bulbar-innervated muscle function by Norris scale bulbar-innervated muscle subscore. Cuffless tubes were replaced by cuffed ones when hypoventilation developed despite increasing uTIPPV volumes. RESULTS: The survival of 22 patients was prolonged by continuous noninvasive ventilatory support dependence for 7.8 +/- 8.1 mos (range, 1-36 mos; median, 5 mos) after 13.9 +/- 11.2 mos (range, 2-36 mos) of part-time noninvasive ventilatory support. Six of these and 22 others underwent tracheotomy and initially used uTIPPV effectively. For ten of the 28 (35.7%) patients, the tubes had to be replaced by cuffed ones after 5.7 +/- 7.8 mos with the other 18 still using tracheostomy intermittent positive pressure ventilation volumes via uncuffed tubes for 20.2 +/- 17.6 mos at data collection. Pretracheotomy FVC was significantly lower in the ten patients who eventually required cuffed tubes (0.70 +/- 0.44 vs. 1.06 +/- 0.43 L, P < 0.05). The bulbar-innervated muscle was significantly lower when the uTIPPV users required cuffed TIPPV than when beginning uTIPPV (Norris scale bulbar-innervated muscle subscore, 3.20 +/- 1.30 vs. 8.00 +/- 3.20, P < 0.05), respectively. CONCLUSIONS: Noninvasive and tracheostomy IPPV via cuffless tubes can prolong survival for patients with amyotrophic lateral sclerosis until excessive air leak and hypoventilation necessitate a cuffed tube.

Neonatal nasal intermittent positive pressure ventilation: a survey of practice in England.

BACKGROUND: Less invasive techniques of respiratory support are increasingly popular. OBJECTIVE: To determine how widespread the use of neonatal nasal intermittent positive airway pressure (NIPPV) has become and describe the range of practice used in NIPPV in England. METHODS: 95 English Neonatal intensive care units were asked to provide information about NIPPV devices, interfaces, indications, guidelines, use of synchronisation, complications, settings and weaning. RESULTS: 91 (96%) units replied. NIPPV was used by 44/91 (48%) units; few complications were seen. 34/44 (77%) used a synchronising device, 35/44 (80%) used NIPPV for "rescuing" babies for whom continuous positive airway pressure failed-59% routinely after extubation and 16% as a first-line treatment. A wide range of pressure and rate settings were used. CONCLUSIONS: In England, NIPPV is commonly used, with considerable variability in the techniques applied. The wide range of clinical approaches highlights the paucity of evidence available. More evidence is needed to establish best practice.

Measurement of pressure-time product during spontaneous assisted breathing by rapid interrupter technique.

BACKGROUND: Measuring the work of breathing of patients undergoing spontaneous assisted ventilation can be useful to monitor and titrate ventilatory support. The aim of this study was to obtain measurements of the pressure generated by the respiratory muscles (PMUSC) and the derived pressure-time product (PTP; a good indicator of the metabolic work of breathing), performing the rapid interrupter technique with a commercial ventilator. METHODS: A Draeger Evita 4 ventilator (Draeger Medical, Lubeck, Germany) was controlled by a personal computer to rapidly interrupt the airway flow at different times and volumes of the respiratory cycle during pressure-support ventilation. From the airway pressure tracing after the occlusion, the authors estimated the alveolar pressure and PMUSC; the integration of PMUSC values over the inspiratory time yields the measurement of PTP. Esophageal pressure measurements were used as a reference. After a bench study of the valves' performance, the authors performed 11 measurement sequences in eight patients. RESULTS: The closure times for the inspiratory and expiratory valves were 74 +/- 10 and 61 +/- 13 ms, respectively. The interrupter technique provided a reliable estimate of PMUSC (PMUSC, occl = 1.00 . PMUSC, pes + 0.19; r = 0.88; 95% confidence interval for agreement, +5.49/-5.32 cm H2O). PTPoccl tightly correlated with PTPpes (PTPoccl = 0.95 . PTPpes + 0.13; r = 0.96; 95% confidence interval, 1.94/-1.61 cm H2O . s). CONCLUSION: The rapid interrupter technique can be performed by means of a commercial ventilator, providing reliable measurement of PMUSC and PTP.

Pressure-regulated volume control ventilation vs synchronized intermittent mandatory ventilation for very low-birth-weight infants: a randomized controlled trial.

OBJECTIVE: To test the hypothesis that pressure-regulated volume control (PRVC), an assist/control mode of ventilation, would increase the proportion of very low-birth-weight infants who were alive and extubated at 14 days of age as compared with synchronized intermittent mandatory ventilation (SIMV). STUDY DESIGN: Ventilated infants with birth weight of 500 to 1249 g were randomized at less than 6 hours of age either to pressure-limited SIMV or to PRVC on the Servo 300 ventilator (Siemens Electromedical Group, Danvers, Mass). Infants received their assigned mode of ventilation until extubation, death, or meeting predetermined failure criteria. RESULTS: Mean +/- SD birth weights were similar in the SIMV (888 +/- 199 g, n = 108) and PRVC (884 +/- 203 g, n = 104) groups. No differences were detected between SIMV and PRVC groups in the proportion of infants alive and extubated at 14 days (41% vs 37%, respectively), length of mechanical ventilation in survivors (median, 24 days vs 33 days, respectively), or the proportion of infants alive without a supplemental oxygen requirement at 36 weeks' postmenstrual age (57% vs 63%, respectively). More infants receiving SIMV (33%) failed their assigned ventilator mode than did infants receiving PRVC (20%). Including failure as an adverse outcome did not alter the overall outcome (39% of infants in the SIMV group vs 35% of infants in the PRVC group were alive, extubated, and had not failed at 14 days). CONCLUSION: In mechanically ventilated infants with birth weights of 500 to 1249 g, using PRVC ventilation from birth did not alter time to extubation.

A randomized trial comparing oxygen delivery on intermittent positive pressure with nasal cannulae versus facial mask in neonatal primary resuscitation.

AIM: To compare, in a prospective clinical trial, oxygen delivery on intermittent positive pressure with nasal cannulae versus facial mask in primary resuscitation of the newborn with moderate asphyxia. METHODS: 617 neonates with moderate asphyxia at birth were randomized: 303 were resuscitated by oxygen on intermittent positive pressure with nasal cannuale and 314 neonates by mask. Resuscitation followed the Neonatal Resuscitation Program guidelines of the American Academy of Pediatrics, 3rd edition. RESULTS: Resuscitation through the nasal route less frequently requires chest compressions and intubations (26 neonates needed chest compression and 20 needed intubation out of 314 resuscitated by mask; five neonates needed chest compression and two needed intubation out of 303 resuscitated by nasal cannulae). Apgar scores, admission rates to neonatal intensive care units, air-leak syndromes, birthweight, gestational age, use of prenatal steroids and deaths did not differ between groups. CONCLUSION: Oxygen delivery on intermittent positive pressure with nasal cannulae in primary resuscitation of the newborn with moderate asphyxia is a less aggressive and potentially advantageous alternative to the traditional oral route.

Increased ventilation with NiIPPV does not necessarily improve exercise capacity in COPD.

Evidence that noninvasive intermittent positive-pressure ventilation (NiIPPV) improves exercise capacity in chronic obstructive pulmonary disease (COPD) is limited. The effectiveness of different ventilators in this setting has not been studied. Three bilevel pressure support ventilators (Bipap S/T 30, Nippy2 and Vpap II ST), applied via a mouthpiece, were compared during submaximal treadmill exercise in eight subjects with COPD. Subjects walked to exhaustion with each of the ventilators and while breathing through the mouthpiece alone, in random order. In addition, four unencumbered walks were performed. The unencumbered distance (mean +/- SD) walked was 259 +/- 123 m. With the mouth-piece alone this decreased to 211 +/- 96 m and fell further to 145 +/- 76 m with NiIPPV. There was no difference between the brands of ventilator. At the break-point of exercise, significant increases were seen in tidal volume and minute ventilation in the ventilator walks compared with the mouthpiece alone. Noninvasive intermittent positive-pressure ventilation increased ventilation but did not improve exercise capacity in the subjects in this study. No significant differences were seen between the ventilators. The effectiveness of this technique and the optimal method of assistance require further clarification.

Salbutamol delivery during non-invasive mechanical ventilation in patients with chronic obstructive pulmonary disease: a randomized, controlled study.

OBJECTIVE: We investigated the clinical response to equivalent doses of salbutamol delivered, via metered dose inhaler (MDI) during non-invasive mechanical ventilation (NIMV-MDI), during spontaneous breathing using a spacer (MDI-Spacer), and also during intermittent positive pressure breathing (IPPB). SETTING: A respiratory intensive care unit. DESIGN: Prospective, randomized, and placebo-controlled study. PATIENTS: Eighteen stable patients with chronic obstructive pulmonary disease (mean FEV1=38.5+/-8.8% predicted). RESULTS: Overall salbutamol administration induced, compared to placebo, a significant improvement in FEV1, irrespective of the mode of administration (+7.9+/-7.1% or +108+/-91 ml for IPPB, +9.6+/-8.8% or 112+/-67 ml for MDI-NIMV (inspiratory pressure=14.3+/-1.8 cmH2O; expiratory pressure=none), and +10.8+/-11.4% or 119+/-114 ml for MDI-Spacer, respectively). DeltaFVC significantly increased from placebo only in MDI-NIMV (+214+/-182 ml P=0.02). A second set of experiments performed in eight patients to ascertain the possible effect of NIMV on pulmonary function tests, showed a significant improvement from baseline values in FVC both after the delivering of placebo or salbutamol via NIMV-MDI (+206+/-147 ml and 208+/-145, respectively). FEV1 significantly increased only after salbutamol. No changes in gas exchange were observed after bronchodilator delivery. CONCLUSIONS: We show that delivery of bronchodilators via MDI with a spacer chamber during NIMV is feasible and induces a significant bronchodilator effect compared to placebo, even though it may be slightly less effective than the classical delivery system (MDI-Spacer).

Limb girdle muscular dystrophy type 2A presenting with cardiac arrest.

The occurrence of respiratory failure in progressive neuromuscular disorders is well recognized. This failure is observed most commonly in Duchenne dystrophy but sometimes occurs in Becker's, limb-girdle, and facioscapulohumeral dystrophies. Patients usually present acutely or subacutely with cyanosis and cor pulmonale, with severe decompensation often being precipitated by an acute intercurrent infection. However, cardiopulmonary arrest is an uncommon presentation. A male diagnosed with limb-girdle muscular dystrophy type 2A who presented with cardiopulmonary arrest that was precipitated by an upper respiratory tract infection is presented. The nocturnal application of noninvasive intermittent positive pressure ventilation with a bilevel positive airway pressure (Bi-PAP) device improved his symptoms and quality of life without resorting to more-invasive and more-restrictive forms of support. This report demonstrates an unusual presentation of limb-girdle muscular dystrophy and documents that nocturnal nasal administration of continuous airway pressure using the Bi-PAP device may be sufficient to maintain adequate ventilation in such patients.

[Titration of an effective positive pressure level in the treatment of obstructive sleep apnea syndromes using continuous positive pressure ventilation]. / Titration du niveau de pression positive efficace dans le traitement du syndrome d'apnées obstructives du sommeil par pression positive continue.

The efficacy of continuous airway positive pressure ventilation with a nasal mask mainly depends on the appropriateness of the effective positive pressure level. Conventionally, this level is determined from polysomnographic recordings using progressively increasing pressure levels to determine the point where episodes of apnea, hypopnea and snoring regress in all sleep phases and in all body positions. Since the first description of this method, many other titration methods have been proposed. Some use sophisticated signals such as the analysis of respiratory exertion level or limitation of inspiratory flow to provide a more precise titration which is particularly useful in cases where the classical titration method is insufficiently effective. Inversely, simplified methods have been examined from an economic point of view. These methods do not require the presence of a technician in a specialized laboratory where the waiting list for diagnostic tests is often long. Recordings during naps or short nights have been proposed for the more severe cases. Likewise titrations during simple polygraphy recordings or with an autoCPAP device have been shown to be effective in one-night laboratory recordings. Much work remains to be done to determine the effectiveness of these methods when used in the patient's home as well the long-term effects.

[Long-term breathing via tracheostoma]. / Langzeitheimbeatmung über Tracheostoma.

PATIENTS AND METHODS: From 1988 to 2/1997 we had introduced intermittent positive pressure ventilation (IPPV) in 298 patients. In most cases non-invasive nasal mask ventilation was possible, in 21 patients (7%) a tracheostoma was necessary. These 21 patients were analysed retrospectively due to age, sex, diagnose, ventilation mode, course of illness, home care and costs. RESULTS: We had 13 male and 8 female patients, aged 49 years on average (min. 2, max. 84). 90% had neuromuscular diseases especially muscle dystrophies. Ventilation therapy was performed volume controlled with the cannula unblocked during daytime and blocked at night. Eighteen patients had industrial cannulas (72% Shiley, 28% Rüsch), 3 patients used silver cannulas. Daily ventilation amounted 24 hours in 7 patients, 6 to 14 hours in 14 patients. During the observed time 7 patients remained in stable health situation, in 9 patients the underlying disease was progressive and 5 of them died. IPPV was performed 50.7 months on an average, in living patients 68.8 months, in died 7.6 months. Fifteen patients lived at home, 5 were cared in nursing home, 1 patient stayed in hospital. Outside the hospital the bigger part of costs was paid by sick funds and care funds, the smaller part by social welfare offices. Often costs were divided. Total costs for caring about 24 hours ventilated patient at home amounted up to 21,000 German marks each month.

[Respiratory pattern and respiratory strain in automatic tube compensation and inspiratory pressure support]. / Atemmuster und Atemanstrengung bei automatischer Tubuskompensation und inspiratorischer Druckunterstützung.

STUDY OBJECTIVE: To investigate whether automatic tube compensation (ATC) or conventional pressure support (PS) is suitable to compensate for the work of breathing imposed by the breathing circuit without altering the breathing pattern. METHODS: Breathing pattern and work of breathing were measured in healthy volunteers. After a 20 min period of quiet breathing through a mouth piece (control) the volunteers were breathing through a 8.0 mm ID endotracheal tube (ETT) with four different settings: CPAP at 0 mbar, ATC, PS 5 mbar, PS 10 mbar. Each mode was applied for a 20 min period. At the end of each period data from 10 consecutive breaths were analyzed and averaged. Tidal volume (VT), breathing frequency (f), and minute ventilation (Ve) were determined from the stored gas flow tracings. Work of breathing was assessed as the pressure time product (PTP) calculated from the transdiaphragmatic pressure (Pdi) using a combined esophageal and gastric balloon catheter. RESULTS: During the control period the breathing pattern was as follows: VT = 882 +/- 277 ml, f = 13.7 +/- 5/min, Ve = 11.5 +/- 4.2 L/min. Maximal Pdi was 9.2 +/- 5.4 mbar and PTP was 11.3 +/- 7.1 mbar x s. Breathing CPAP through the ETT resulted in a slight increase in Pdi (10.8 +/- 5.4 mbar) and PTP (14.8 +/- 10.4 mbar x s) with an unchanged breathing pattern. However, for the same amount of unloading from respiratory workload ATC did not alter the breathing pattern, whereas PS 5 mbar and PS 10 mbar resulted in a clear increase in VT (1014 +/- 202 ml, 1336 +/- 305 ml, respectively). CONCLUSION: From the presented data in healthy volunteers it might be concluded that ATC and PS 5 mbar and 10 mbar are suitable modes for unloading the respiratory system from work imposed by the breathing circuit. ATC does not alter the breathing pattern in contrast to PS which results in an increased tidal volume. Therefore, the exact compensation of the work imposed by the ETT during ATC seems to be advantageous over ATC to assess the actual breathing pattern.

[Long-term home care of respiratory insufficiency with oxygen and IPPB in France and in my own practice]. / Langzeit-Hausbehandlung bei Ateminsuffizienz mit sauerstoff und IPPB, in Frankreich und in meiner Praxis.

Contrary to the conditions in France, long-term home therapy in respiratory deficient patients in Germany is not strictly controlled by house-calls; the indications for therapy are not supervised by regular examinations of the patient's status; and the need for the apparatus is not re-evaluated. During my house-calls I found patients overstrained and not sufficiently instructed, and apparatus defective, not maintained, and inappropriately used. Some examples may illustrate the situation which could be improved by a caring network like A.N.T.A.D.I.R. in France.

[Noninvasive nocturnal nasal mask ventilation (NIPPV) in childhood and adolescence. Dresden experiences with 11 patients]. / Nichtinvasive nächtliche nasale Maskenbeatmung (NIPPV) im Kindes- und Jugendalter. Dresdener Erfahrungen mit elf Patienten.

BACKGROUND: There are only small experiences with mechanical ventilation via nasal mask in childhood. PATIENTS AND METHODS: Eleven patients using NIPPV (9 patients aged 4 to 18 years and 2 patients with cystic fibrosis aged 20 and 25 years). RESULTS: NIPPV was effective in all 11 patients. Seven patients needed supplemental oxygen. Theophyllin, Almitrin and Salbutamol could support the nasal ventilation in special conditions. CONCLUSION: Intermittent ventilation via nasal mask is a noninvasive and effective treatment of chronic respiratory failure in childhood. Monitoring with continuous pulse-oximetry is necessary.

Predictors of patient adherence to long-term home nebulizer therapy for COPD. The IPPB Study Group. Intermittent Positive Pressure Breathing.

STUDY OBJECTIVE: Patients with moderate to severe COPD are frequently prescribed expensive and complicated therapies that require adjustments in usual activities of daily living. However, little is known about factors that are associated with adherence to such treatment. The objective of this study was to identify characteristics of patients who were adherent to long-term home nebulizer therapy. DESIGN: Patients were stratified into two adherence groups based on average minutes of nebulizer use each day. A logistic regression model was developed to predict adherence based on baseline variables. A questionnaire was administered to patients to assess reasons for adherence to therapy. SETTING: Five clinical centers in the United States and Canada. PARTICIPANTS: Nine hundred eighty-five patients with moderate to severe COPD enrolled in the Intermittent Positive Pressure Breathing (IPPB) Trial. INTERVENTIONS: Long-term home IPPB and nebulizer therapy. MEASUREMENTS AND RESULTS: Altogether 50.6% of patients were adherent, and 49.4% were nonadherent. Among baseline variables, good adherence was predicted by white race, married status, abstinence from cigarettes and alcohol, serum theophylline level > or = 9 micrograms/mL, more severe dyspnea, and reduced FEV1 (p < 0.05). Subjects who were adherent to nebulizer therapy were older, better educated, had a stable lifestyle, were more likely to report that the therapy made them feel better, and were more likely to keep clinic appointments. CONCLUSIONS: Sociodemographic, physiologic, and quality of life variables were associated with adherence to long-term nebulizer therapy.