Use Of Nasal Continuous Positive Airway Pressure Research Articles

Pour ou contre une utilisation précoce de la pression positive continue nasale et du surfactant exogène au cours de la maladie des membranes hyalines. Arguments physiopathologiques

The use of nasal CPAP in the treatment of respiratory distress syndrome in very premature newborns follows pathophysiological basis. The authors emphasize the usefulness of nasal CPAP and surfactant in the treatment of respiratory distress syndrome. The aim of this strategy is to reduce alveolar atelectasis, thus reducing the incidence and the severity of respiratory distress syndrome, together with a possible reduction of the incidence of bronchopulmonary dysplasia.

Indications for Surfactant Therapy—The aAPo2 Coming of Age

Indications for administration of surfactant to infants with established respiratory distress syndrome (RDS; rescue therapy) remains an area of continued investigation. Current recommendations vary from use in infants who are intubated and have an aAPO2 <0.22 to use in infants receiving >/=40% oxygen administered in a hood when the PaO2 is <80 TORR (aAPO2 approximately <0.36). This commentary is written in response to the article by Verder et al, in this issue of Pediatrics, who evaluated early versus late treatment of RDS in 60 preterm infants <30 weeks' gestation receiving nasal continuous positive airway pressure (CPAP). Early-treated infants (aAPO2, 0.22 to 0.35; mean, 0.26) had a lower incidence of mechanical ventilation or death (21%) than did late-treated infants (63%), who did not receive surfactant treatment until the aAPO2 was <0.22 (0.15 to 0.21; mean, 0.16). The authors conclude that although approximately half of infants <30 weeks' gestation with RDS can be treated with nasal CPAP alone, early treatment with surfactant when the aAPO2 is 0.22 to 0.36 reduced significantly the need for mechanical ventilation. Limitations of applicability of the study to widespread use include determination of PO2 values from transcutaneous measurements, which may vary from those obtained from arterial samples and affect significantly aAPO2 ratios. Likewise, use of nasal CPAP significantly affects oxygenation, and interpretation of results cannot be extrapolated to intubated infants or those receiving oxygen delivered under a hood. Nonetheless, the use of the aAPO2 ratio and early administration of surfactant are supported by this study.

Diagnostic approach to obstructive sleep apnea in children.

Obstructive sleep apnea syndrome (OSAS) in childhood is a disorder of breathing during sleep characterized by prolonged partial upper airway obstruction and/or intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep patterns. A spectrum of severity related to the degree of upper airway resistance, to the duration of the disease, to the presence or absence of hypoxemia episodes, and to certain clinical features can be described. Symptomatic children may not fit the criteria for diagnosis established for OSAS in adults; age-specific standards are needed. Both anatomical factors that increase upper airway resistance, e.g. adenotonsillar hypertrophy, and functional processes that decrease upper airway tone, e.g. REM sleep, contribute to the pathogenesis of pediatric OSAS. Sequelae of OSAS in children include neurobehavioural abnormalities, stunting of growth, and cor pulmonale. Both the history and physical examination should target the sleeping child; parents often report loud snoring, difficulty breathing, and obstructive apneas. The gold standard investigation to establish the diagnosis and to quantitate disease severity is overnight polysomnography. Home cardiopulmonary sleep studies have been shown to be an accurate and practical alternative to overnight laboratory polysomnography for routine evaluation of non-complex children with adenotonsillar hypertrophy. Children with documented severe OSAS are at increased post-operative risk for airway compromise and should be observed and monitored carefully. Adenotonsiliectomy is the most common therapy for OSAS in children; as a second-line treatment, the use of nasal CPAP in children with OSAS has been very successful in experienced hands.

Long-Term Evolution of Daytime Somnolence in Patients With Sleep Apnea/Hypopnea Syndrome Treated by Continuous Positive Airway Pressure

We demonstrated in a previous study that excessive daytime sleepiness (EDS) in patients who have sleep apnea/hypopnea syndrome (SAHS) and are undergoing continuous positive airway pressure (CPAP) treatment improved differently in two groups of patients: in group I, multiple sleep latency tests (MSLT) were normalized after 50 days of treatment (individual value > 10 minutes), whereas they remained low (individual value < 10 minutes) in group II, with a significant difference between groups. To evaluate the long-term evolution of daytime somnolence under nasal CPAP treatment, five patients from group I and seven patients from group II underwent a new polysomnography and MSLT 4 years after the previous study. Clinical, polysomnographic and MSLT results obtained at baseline before treatment (T1), after the initial 50-day period of CPAP treatment (T2), and after 4 years (T3) were compared. The significant difference in mean MSLT value between the two groups previously observed at T1 and T2 disappeared at T3 (group I: 12.4+/-5.9 minutes; group II: 9.7+/-5.9 minutes). We found that this long-term improvement in excessive daytime somnolence was independent of the initial MSLT value, the severity of SAHS, and the initial MSLT changes under nasal CPAP. Long-term MSLT evolution was significantly correlated to CPAP compliance. These results demonstrate that even in the absence of a significant increase in MSLT at the beginning of CPAP treatment, further improvement is still possible several years later, which may encourage the regular, long-term use of nasal CPAP by patients.

Long-Term Compliance with Continuous Positive Airway Pressure in Patients with Obstructive Sleep Apnea Syndrome

A ten-year retrospective analysis of the clinical features and survival of 60 Saudi children with systemic lupus erythematosus (SLE) was made. All the patients fulfilled the 1982 American College of Rheumatologyâs revised criteria for SLE and had had the disease at or before the age of 16 years. The female to male ratio was 5:1, the mean age of onset was 12.1 years (range 1.6-16 years), and the mean duration of follow-up was 4.7 years (range 2.2-11). Thirty-eight patients (63%) were diagnosed correctly before referral to KFSH&RC or KKUH. The mode of presentation was as follows: 55 patients had musculoskeletal involvement (91.6%), 49 patients had skin involvement (81.6%), 40 patients had hematological abnormalities (66.6%), 39 patients had renal disease (65%), 10 patients had pulmonary involvement (16%), 23 patients had cardiovascular disease (38%) and 18 patients had central nervous system involvement. During the study period four patients died (6.6%)âtwo of renal failure, one from meningitis and one from severe sepsis. This is the largest collection of childhood systemic lupus erythematosus from the Middle East and it shows that SLE is more common in Saudis than was hitherto believed, and that it has a high rate of organ involvement.

Unusual Complication of Nasal CPAP: Subcutaneous Emphysema Following Facial Trauma

Subcutaneous emphysema is an unusual complication of nasal continuous positive airway pressure (CPAP). We report a case of a 58-year-old man who fell and sustained mild facial trauma to the left side of his head. After using CPAP the following night, he developed diffuse subcutaneous emphysema of his face and left neck. He discontinued CPAP, and his symptoms improved. The potential mechanisms of this patient's subcutaneous emphysema and the prior reports of this complication following facial trauma or dental procedure without use of CPAP are reviewed. Although there are case reports of bacterial meningitis and pneumocephalus following use of nasal CPAP, we are not aware of any prior reports of subcutaneous emphysema following use of CPAP. In light of our experience and the above related case reports, we would suggest nasal CPAP be withheld temporarily in the setting of acute facial trauma.

Nasal-Continuous Positive Airway Pressure in the Treatment of Near-Drowning in Freshwater

In patients who have experienced near-drowning, hypoxemia is the major clinical consequence. We report two cases of patients who have experienced near-drowning in freshwater who were successfully treated with nasal-continuous positive airway pressure (N-CPAP) plus oxygen therapy. Both patients presented a radiographic appearance of bilateral pulmonary edema. We suggest the use of N-CPAP as an easier and less costly alternative to tracheal intubation for treating near-drowning in patients who are breathing spontaneously and who have not experienced loss of consciousness.

The Pharyngeal Critical Pressure: The Whys and Hows of Using Nasal Continuous Positive Airway Pressure Diagnostically

The Pharyngeal Critical Pressure: The Whys and Hows of Using Nasal Continuous Positive Airway Pressure Diagnostically

Obstructive sleep apnea: the use of nasal CPAP in 80 children.

This is a retrospective review of children 15 years of age or younger, who underwent overnight sleep studies between 1980 and 1993. All were diagnosed and treated for obstructive sleep apnea (OSA). Overnight studies were performed for OSA in 413 children. One hundred seventy-five (42.4%) children were treated with adenotonsillectomy and 80 (19.4%) with nasal mask continuous positive airway pressure (nCPAP). The proportion of male children was greater than expected in both the entire study group (69%, p < 0.001) and in those treated with nCPAP for OSA (71% p < 0.001). There was no significant difference between the mean age of the children treated with nCPAP (5.7 +/- 0.5 yr) and the entire group studied (5.04 +/- 0.21 yr). A greater proportion of the children who received nCPAP therapy had a congenital syndrome or malformation than in the group with OSA as a whole; 27.7% of children assessed for OSA were affected, and 53% of those children with OSA who received treatment with nCPAP (p < 0.001). Therapy with nCPAP (mean duration 15 +/- 3 mo, mean pressure 7.9 cm H2O) eliminated the signs of OSA in 72 children (90%). Respiratory disturbance index fell from a mean of 27.3 +/- 20.2 to 2.55 +/- 2.74 (p < 0.001). Eight of 32 children who underwent pressure determination studies could not tolerate nCPAP above an upper limit because of hypoventilation or frequent central apneas. Nevertheless, we conclude that nCPAP is an effective and generally well-tolerated therapy for treatment of OSA in infants and children.

The use of nasal CPAP in children

The use of nasal CPAP in children

Facilitation of Fiberoptic Nasotracheal Intubation in a Morbidly Obese Patient by Simultaneous Use of Nasal CPAP

A morbidly obese patient was emergently nasotracheally intubated using a fiberoptic bronchoscope. Simultaneous application of 20 cm H2O nasal continuous positive airway pressure (CPAP) to the contralateral naris using a nasal pillow helped maintain ventilation of the patient during intubation and greatly facilitated visualization of anatomic landmarks and translaryngeal passage of the bronchoscope. Fiberoptic video images of this patient's hypopharynx demonstrate the pharyngeal splinting action of nasal CPAP thus applied. This is a novel approach to difficult intubation of the obese patient.

Predictive Factors of Long-term Compliance With Nasal Continuous Positive Airway Pressure Treatment in Sleep Apnea Syndrome

The long-term acceptability of treatment with nasal continuous positive airway pressure (CPAP) was studied prospectively in 44 patients with obstructive sleep apnea syndrome. At 14 months on the average after starting treatment with CPAP, 30 patients (68 percent) were found to be compliant (characterized by use of the apparatus every night throughout the night, for more than 5 h per night). The daily use of nasal CPAP was significantly correlated to the initial apnea/hypopnea index (p = 0.013; r = 0.37), as well as to the percentage of light sleep (p = 0.045; r = 0.30) and slow-wave sleep (p = 0.037; r = -0.31) during the initial polygraphic recording. We found a strong correlation between the daily use of nasal CPAP and the difference in the apnea/hypopnea index (p = 0.025; r = -0.34), the difference in mean oxygen saturation during sleep (p = 0.013; r = 0.38), and the difference in hypersomnia scores (p = 0.006; r = -0.40) obtained before and after treatment by nasal CPAP. Thus, patients used CPAP much more if they had an initial significant clinical handicap and if they were aware of the beneficial effects of CPAP. Under these conditions, patients tended to use the apparatus for the optimal length of time, regardless of the side effects linked to the treatment. This ensured efficacy and the maintenance of good compliance. This study confirms the importance of supervision of the time counter, as well as regular encouragement of patients to use the treatment as long as possible each night, in order to extract a maximum benefit from treatment by nasal CPAP.

Flow-regulatory function of upper airway in health and disease: A unified pathogenetic view of sleep-disordered breathing

Although the Starling resistor behavior of the upper airway during sleep has been well established in health and disease, its physiological implications have not been fully appreciated. The purposes of the present communication are to reassess the current state of knowledge within the framework of the Starling resistor concept and to examine the implications of the concept on homeostatic feedback respiratory control and the pathogenesis of the sleep apnea syndrome. The main inferences drawn from the assessment include: (1) Owing to the Starling resistor properties of the upper airway and the well-organized neurochemical control mechanism, the upper airway performs important homeostatic flow regulatory function; it appropriately dampens the potentially unstable breathing during sleep and prevents the PaCO2 from falling below the apneic threshold; (2) Under certain conditions, the upper airway flow regulatory function fails to achieve appropriate dampening, leading to development of a variety of sleep-related breathing disorders that include underdamping due to overly sensitive central chemoresponsiveness and/or excessive lung to chemoreceptor transport lag--central sleep apnea; overdamping due to upper airway obstructive dysfunction--obstructive sleep apnea and/or hypopnea; and, finally, conditions with mixed features of central underdamping with coexisting collapsible upper airway; and (3) Successful treatment of these conditions requires restoration of appropriate damping. The overdamping imposed by the faulty upper airway is effectively reduced by surgical and medical approaches, and by application of nasal continuous positive airway pressure (CPAP). Reduction of PaCO2 by use of acetalzolamide and/or aminophylline reduces the plant gain, thus effectively offsetting the underdamping of central origin. Owing to the dual effect of nasal CPAP on the upper airway and respiratory pump, use of nasal CPAP can also effectively reduce the plant gain, accounting for the therapeutic effect of nasal CPAP on the central sleep apnea.

Objective measurement of patterns of nasal CPAP use by patients with obstructive sleep apnea.

Obstruction of the upper airway during sleep (OSAS) is widely treated by having patients self-administer nasal continuous positive airway pressure (CPAP). To obtain objective evidence of the patterns of CPAP use, information was gathered from two urban sites on 35 OSAS patients who were prescribed CPAP for a total of 3,743 days. Patients were given CPAP machines that contained a microprocessor and monitor that measured actual pressure at the mask for every minute of each 24-h day for an average of 106 days per patient. They were not aware of the monitor inside the CPAP machines. Monitor output was compared with patients' diagnostic status, pretreatment clinical and demographic characteristics, and follow-up self-reports of CPAP use, problems, side effects, and aspects of daytime fatigue and sleepiness. Patients attempted to use CPAP an average of 66 +/- 37% of the days monitored. When CPAP was used, the mean duration of use was 4.88 +/- 1.97 h. However, patients' reports of the duration of CPAP use overestimated actual use by 69 +/- 110 min (p < 0.002). Both frequency and duration of CPAP use in the first month reliably predicted use in the third month (p < 0.0001). Although the majority (60%) of patients claimed to use CPAP nightly, only 16 of 35 (46%) met criteria for regular use, defined by at least 4 h of CPAP administered on 70% of the days monitored. Relative to less regular users, these 16 patients had more years of education (p = 0.05), and were more likely to work in professional occupations.(ABSTRACT TRUNCATED AT 250 WORDS)

Sleep-Disordered Breathing in Patients with Duchenne Muscular Dystrophy Using Negative Pressure Ventilators

We studied the occurrence of nocturnal disordered breathing events and O2 desaturations in 12 patients with late-stage Duchenne muscular dystrophy (DMD) using negative pressure ventilators. We also assessed the effects of O2 supplementation and nasal continuous positive airway pressure (CPAP) on disordered breathing events in selected patients and examined sleep quality in a small subgroup. Average age was 23 + 2 years and FVC was 293 + 33 ml. Eleven of the 12 patients had more than five disordered breathing events per hour during nocturnal monitoring, and the lowest O2 saturation was < 85 percent in nine patients. Nasal O2 (2 L/min) during negative pressure ventilation in four patients did not alter the frequency of disordered breathing events, prolonged the mean and maximum durations of events, and failed to eliminate severe O2 desaturations in two patients. Nasal CPAP was used in two patients during negative pressure ventilation and completely eliminated disordered breathing events in both. Overnight polysomnography during negative pressure ventilation in three patients demonstrated frequent awakenings that fell in frequency following elective tracheostomy in two patients and use of nasal CPAP in one. We conclude that negative pressure ventilation in patients with late-stage DMD is associated with frequent disordered breathing events and severe O2 desaturations in many patients. Concomitant use of O2 supplementation may prolong the events, but a switch to positive pressure ventilation or addition of nasal CPAP is effective therapy.

Home Care for Respiratory Problems

This article reviews current recommendations for the home care of geriatric patients with chronic pulmonary disease. Special attention is given to new bronchodilators, indications for home oxygen and ventilator use, as well as the use of nasal CPAP in elderly sleep apnea patients. The necessity of do not resuscitate (DNR) orders is also discussed.

Successful Use of Nasal-CPAP for Obstructive Sleep Apnea in Hunter Syndrome with Diffuse Airway Involvement

A patient with Hunter syndrome and diffuse airway obstruction had daytime hypersomnolence, snoring, and alveolar hypoventilation. Polysomnography showed severe obstructive sleep apnea. In the past, all reported cases of sleep apnea in patients with mucopolysaccharidoses had been treated with tonsillectomy/adenoidectomy or tracheostomy. This patient, in whom tracheostomy would have been very difficult due to the diffuse nature of his airway involvement, was successfully treated with high pressure nasal CPAP and supplemental oxygen.

Measurement of pharyngeal volume by digitized magnetic resonance imaging. Effect of nasal continuous positive airway pressure.

Pharyngeal size is thought to play an important role in the pathogenesis of snoring and obstructive sleep apnea. It has been hypothesized that nasal continuous positive airway pressure (CPAP) works by enlarging pharyngeal size and splinting the airway open. In this study, we selected 12 heavy snorers and abolished their snoring with nasal CPAP in our sleep laboratory. Using magnetic resonance imaging and a computer program utilizing a digitizing pad, we measured these awake subjects' pharyngeal volumes without and with the nasal CPAP apparatus on at the level used to abolish their snoring. We found an average 27.7% increase in pharyngeal volume with nasal CPAP. We have visually shown an increase in pharyngeal size with the use of nasal CPAP in a cohort of heavy snorers.

Objective measurement of compliance with nasal CPAP treatment for obstructive sleep apnoea syndrome

Compliance with nasal continuous positive airway pressure (CPAP) has become a major concern, since this treatment is efficacious, but constraining. In 46 consecutive obstructive sleep apnoea (OSA) patients, we measured compliance with nasal CPAP by establishing a mean rate of use, with a built-in time counter read at three-month intervals, over a mean follow-up period of 232 +/- 27 days. The mean rate of use in the whole group was 5.14 +/- 0.31 hours per day. The acceptance rate was 90.9-93.2%, showing that patient acceptance is not a limitation in the use of nasal CPAP.

Hypercapnia in the Obstructive Sleep Apnea Syndrome: A Reevaluation of the “Pickwickian Syndrome”

The mechanisms of hypercapnia in eight patients with the "Pickwickian" syndrome and obstructive sleep apnea (OSAS) were evaluated pretherapy and posttherapy (tracheostomy in seven patients and chronic nocturnal use of nasal CPAP in one). Four patients (correctors) became eucapnic within two weeks of therapy. Four others (noncorrectors) remained hypercapnic. Neither residual apneas, changes in pulmonary function, change in anatomic dead space, nor changes in ventilatory chemoresponsiveness differentiated the two groups, nor did the last three factors account for return to eucapnia in the correctors. The results indicated two separate mechanisms exist for chronic hypercapnia in OSAS: a critical balance between the ventilation during the time spent awake and hypoventilation due to apneas, a mechanism removed by treatment for obstructive apnea; and sustained hypoventilation independent of the apnea phenomenon and therefore not correctible. The subset of patients with the second mechanism appears to represent the true "Pickwickian" syndrome and can be identified before therapy by measuring a low level of ventilation in the sustained awake state.