Effectiveness of CPAP vs. Noninvasive Ventilation Based on Disease Severity in Obesity Hypoventilation Syndrome and Concomitant Severe Obstructive Sleep Apnea.

RATIONALE: Obesity hypoventilation syndrome (OHS) with concomitant severe obstructive sleep apnea (OSA) is treated with CPAP or noninvasive ventilation (NIV) during sleep. NIV is costlier, but may be advantageous because it provides ventilatory support. However, there are no long-term trials comparing these treatment modalities based on OHS severity. OBJECTIVE: To determine if CPAP have similar effectiveness when compared to NIV according to OHS severity subgroups. METHODS: Post hoc analysis of the Pickwick randomized clinical trial in which 215 ambulatory patients with untreated OHS and concomitant severe OSA, defined as apnoea-hypopnea index (AHI)≥30events/h, were allocated to NIV or CPAP. In the present analysis, the Pickwick cohort was divided in severity subgroups based on the degree of baseline daytime hypercapnia (PaCO2 of 45-49.9 or ≥50mmHg). Repeated measures of PaCO2 and PaO2 during the subsequent 3 years were compared between CPAP and NIV in the two severity subgroups. Statistical analysis was performed using linear mixed-effects model. RESULTS: 204 patients, 97 in the NIV group and 107 in the CPAP group were analyzed. The longitudinal improvements of PaCO2 and PaO2 were similar between CPAP and NIV based on the PaCO2 severity subgroups. CONCLUSION: In ambulatory patients with OHS and concomitant severe OSA who were treated with NIV or CPAP, long-term NIV therapy was similar to CPAP in improving awake hypercapnia, regardless of the severity of baseline hypercapnia. Therefore, in this patient population, the decision to prescribe CPAP or NIV cannot be solely based on the presenting level of PaCO2.

Effectiveness of CPAP vs. Noninvasive Ventilation Based on Disease Severity in Obesity Hypoventilation Syndrome and Concomitant Severe Obstructive Sleep Apnea / El impacto de la terapia de presión positiva de larga duración en el síndrome de hipoventilación-obesidad en función de la gravedad de la enfermedad

Rationale: Obesity hypoventilation syndrome (OHS) with concomitant severe obstructive sleep apnea (OSA) is treated with CPAP or noninvasive ventilation (NIV) during sleep. NIV is costlier, but may be advantageous because it provides ventilatory support. However, there are no long-term trials comparing these treatment modalities based on OHS severity.ObjectiveTo determine if CPAP have similar effectiveness when compared to NIV according to OHS severity subgroups.MethodsPost hoc analysis of the Pickwick randomized clinical trial in which 215 ambulatory patients with untreated OHS and concomitant severe OSA, defined as apnoea-hypopnea index (AHI)≥30events/h, were allocated to NIV or CPAP. In the present analysis, the Pickwick cohort was divided in severity subgroups based on the degree of baseline daytime hypercapnia (PaCO2 of 45–49.9 or ≥50mmHg). Repeated measures of PaCO2 and PaO2 during the subsequent 3 years were compared between CPAP and NIV in the two severity subgroups. Statistical analysis was performed using linear mixed-effects model.Results204 patients, 97 in the NIV group and 107 in the CPAP group were analyzed. The longitudinal improvements of PaCO2 and PaO2 were similar between CPAP and NIV based on the PaCO2 severity subgroups.ConclusionIn ambulatory patients with OHS and concomitant severe OSA who were treated with NIV or CPAP, long-term NIV therapy was similar to CPAP in improving awake hypercapnia, regardless of the severity of baseline hypercapnia. Therefore, in this patient population, the decision to prescribe CPAP or NIV cannot be solely based on the presenting level of PaCO2. (AU)

Introducción: El síndrome de hipoventilación-obesidad (SHO) con apnea obstructiva del sueño (AOS) grave concomitante se trata con CPAPo ventilación no invasiva (VNI) durante el sueño. La VNI es más costosa, pero puede ser beneficiosa porque proporciona soporte ventilatorio; sin embargo, no existen estudios a largo plazo que comparen estas modalidades de tratamiento basándose en la gravedad del SHO.ObjetivoDeterminar si la CPAP tiene una eficacia similar a la VNI según los subgrupos de gravedad del SHO.MétodosAnálisis a posteriori del ensayo clínico aleatorizado Pickwick en el que 215 pacientes ambulatorios con SHO sin tratar y con AOS grave concomitante (definida como un índice de apnea-hipopnea [IAH] ≥ 30 episodios/hora) recibieron tratamiento con VNI o CPAP. En el presente análisis, la cohorte Pickwick se dividió en subgrupos según la gravedad basándose en el grado de hipercapnia diurna al inicio del estudio (PaCO2 de 45-49.9mm Hg o ≥ 50mm Hg). Se compararon las mediciones periódicas de PaCO2 y PaO2 durante los 3 años siguientes entre la CPAP y la VNI entre los dos subgrupos de gravedad. Se realizó un análisis estadístico utilizando un modelo lineal mixto.ResultadosSe analizaron 204 pacientes, 97 en el grupo de VNI y 107 en el grupo de CPAP. Las mejoras lineales de PaCO2 y PaO2 fueron similares entre la CPAP y la NIV según los subgrupos de gravedad en función de la PaCO2.ConclusiónEn los pacientes ambulatorios con SHO y AOS grave concomitante a los que se trató con VNI o CPAP, el tratamiento a largo plazo con VNI resultó similar a la CPAP, en cuanto a la mejora de la hipercapnia en vigilia, independientemente de la gravedad de la hipercapnia de inicio. Por lo tanto, en esta población de pacientes la decisión de prescribir CPAP o VNI no puede basarse exclusivamente en el nivel de partida de PaCO2. (AU)