Obstructive sleep apnea-hypopnea syndrome in patients with severe chronic respiratory insufficiency. / Síndrome de apnea-hipopnea durante el sueño en pacientes con insuficiencia respiratoria crónica grave.

INTRODUCTION AND OBJECTIVE: Although sleep disordered breathing is common in patients with a severe chronic respiratory insufficiency (SCRI), there is few information on its prevalence. Our aim was to describe the prevalence and characteristics of the obstructive sleep apnea-hypopnea syndrome (OSAHS) in these patients. MATERIAL AND METHODS: Prospective and observational study carried out on patients with a SCRI included in a waiting list for a lung transplantation and who had undergone a standard polysomnography. RESULTS: A total of 105 patients were examined, of which 85 met the study's inclusion criteria. The prevalence of the OSAHS was 24.7%, with 19% of cases being severe. The most common underlying respiratory condition was COPD (62%). The OSAHS was linked to the male gender (P=.002), weight (P=.013), BMI (P=.034) and neck circumference (P=.01). Although most patients experienced symptoms suggestive of an OSAHS, the average score obtained in the Epworth Sleepiness Scale was low. CONCLUSIONS: We observed a high prevalence of OSAHS in patients with a SCRI but without clinical data suggestive of its diagnosis; hence, we believe that sleep studies should be carried out in these patients given the low pre-test clinical suspicion of the disease.

Videolaryngoscopy With Noninvasive Ventilation in Subjects With Upper-Airway Obstruction.

BACKGROUND: Noninvasive ventilation (NIV) titration may be difficult when dynamic airway obstruction episodes persist, even with high expiratory positive airway pressure (EPAP). We aimed to determine the usefulness of videolaryngoscopy during NIV for identifying mechanisms and sites of obstruction and for providing a guide for their resolution in difficult-to-titrate subjects. METHODS: When obstructions during NIV were present in the built-in software, EPAP was raised to 12 cm H2O. If obstructions persisted, a polygraphy during NIV was performed; if the events occurred with effort, a videolaryngoscopy with nasal and oronasal masks in awake subjects was performed. RESULTS: In a population of 208 subjects in whom NIV was initiated, 13 were identified as difficult to titrate with persistent obstructions during NIV despite an EPAP of 12 cm H2O. Videolaryngoscopy during NIV was able to identify the mechanism and the site of obstruction in all cases. The obstruction under oronasal mask ventilation was due to soft-palate (velum) collapse in 4 subjects, to epiglottic backward movement in 5 other subjects, and to tongue-base obstruction reducing the retroglossal space in 3 more. Videolaryngoscopy during NIV demonstrated improvement in 9 subjects (69%) upon changing to nasal mask and suggested a possible surgical approach in 2 (15%); in one of these 2 subjects, a successful uvulopalatopharyngoplasty was performed. CONCLUSIONS: The use of videolaryngoscopy during NIV in difficult-to-titrate patients may help to identify the sites and mechanisms of obstruction and in some cases may improve quality of ventilation.

Sleep-Related Breathing Disorders and Lung Transplantation.

AIM: Sleep-related breathing disorders (SRBD) are common in patients with lung transplantation (LT); however, there are few data about its prevalence, and none about its pathogenesis or evolution. The SRBD events consist mainly obstructive, central, and mixed apnea, as well as hypopneas. The aim of this study was to describe the prevalence of SRBD before the LT, and its evolution after a period of 1 year follow-up. METHODS: Prospective, observational, descriptive, and analytical study of the SRBD and its evolution in 20 LT patients. The group was studied before and at 6 and 12 months after the LT; in each phase, standard polysomnography was performed, and anthropometric, pathologic, clinical, and pharmacological data were collected. RESULTS: Prevalence of obstructive sleep apnea syndrome was 38% before the LT, 86% at 6 months, and 76% at 12 months after LT. There was a significant increase of weight, body mass index, neck circumference, blood pressure during the first year of follow-up, especially at 6 months after LT. We also observed an increase in the number of central and mixed apneas during the follow-up, although not as remarkable as obstructive apneas. There was no correlation between immunosuppressant studied drugs and any of the studied variables. CONCLUSIONS: We have observed a significant prevalence of obstructive sleep apnea syndrome in patients in waiting list for LT, and LT has an important influence in the evolution of the disorder. In our series, LT has somehow affected the stability of upper airway and ventilatory mechanics.