Respiratory Center Function and Its Impact in Obesity Hypoventilation Syndrome Treatment

Introduction: Patients with obesity hypoventilation syndrome (OHS) need treatment with positive pressure either with continuous (CPAP) or double pressure (NIV). The apnea–hypopnea index (AHI) is considered a key data for making therapeutic decisions. We hypothesized that HR may be an useful tool to establish different phenotypes and individualize treatment in patients with OHS. Our objective was to analyze the role of the respiratory center response to hypercapnia (HR) in the adequacy of positive airway pressure therapy. Method: We included subjects with OHS treated with CPAP or NIV according to AHI and baseline pCO2. We analyzed therapeutic effectiveness and treatment changes prioritizing CPAP if AHI>30/h. Therapy was considered adequate if it was effective after two years. HR was measured with the p0.1/pEtCO2 ratio and its capability to select therapy was analyzed. The statistical study was performed by means comparison (Student's t) and multivariate analysis (logistic regression). Results: 67 subjects were included of 68(11) years old, 37 (55%) males, initially 45 (67%) treated with NIV and 22 (33%) with CPAP, one case was excluded and in 25 (38%) the treatment was changed. Finally, CPAP was adequate for 29 subjects (44%) and NIV for 37 (56%). The CPAP group showed AHI 57/h (24) and p0.1/pEtCO2 0.37cmH2O/mmHg (0.23), NIV group AHI 43/h (35) and p0.1/pEtCO2 0.24 (0.15) with p=0.049 and 0.006. In multivariate analysis, p0.1/pEtCO2 (p=0.033) and AHI>30 (p=0.001) were predictors of adequate therapy. Conclusion: Measuring the RH of the respiratory center helps to select the most appropriate treatment for patients with OHS. (AU)

Respiratory Center Function and Its Impact in Obesity Hypoventilation Syndrome Treatment.

INTRODUCTION: Patients with obesity hypoventilation syndrome (OHS) need treatment with positive pressure either with continuous (CPAP) or double pressure (NIV). The apnea-hypopnea index (AHI) is considered a key data for making therapeutic decisions. We hypothesized that HR may be an useful tool to establish different phenotypes and individualize treatment in patients with OHS. Our objective was to analyze the role of the respiratory center response to hypercapnia (HR) in the adequacy of positive airway pressure therapy. METHOD: We included subjects with OHS treated with CPAP or NIV according to AHI and baseline pCO2. We analyzed therapeutic effectiveness and treatment changes prioritizing CPAP if AHI>30/h. Therapy was considered adequate if it was effective after two years. HR was measured with the p0.1/pEtCO2 ratio and its capability to select therapy was analyzed. The statistical study was performed by means comparison (Student's t) and multivariate analysis (logistic regression). RESULTS: 67 subjects were included of 68(11) years old, 37 (55%) males, initially 45 (67%) treated with NIV and 22 (33%) with CPAP, one case was excluded and in 25 (38%) the treatment was changed. Finally, CPAP was adequate for 29 subjects (44%) and NIV for 37 (56%). The CPAP group showed AHI 57/h (24) and p0.1/pEtCO2 0.37cmH2O/mmHg (0.23), NIV group AHI 43/h (35) and p0.1/pEtCO2 0.24 (0.15) with p=0.049 and 0.006. In multivariate analysis, p0.1/pEtCO2 (p=0.033) and AHI>30 (p=0.001) were predictors of adequate therapy. CONCLUSION: Measuring the RH of the respiratory center helps to select the most appropriate treatment for patients with OHS.

Síndrome de obesidad-hipoventilación: situación hemodinámica basal e impacto de la ventilación no invasiva / Obesity-Hypoventilation Syndrome: Baseline Hemodynamic Status and Impact of non-Invasive Ventilation

INTRODUCCIÓN: El síndrome de obesidad-hipoventilación (SOH) es un factor de riesgo para presentar insuficiencia cardiaca (IC). Algunos estudios relacionan el uso de ventilación no invasiva (VNI) con la alteración de parámetros hemodinámicos. Nuestro objetivo fue describir la situación hemodinámica de un grupo de pacientes con SOH y estudiar el efecto de la VNI. PACIENTES Y MÉTODOS: Con un diseño transversal de mediciones repetidas, se incluyó a pacientes con SOH tratados con VNI en situación estable. Se estudió su hemodinámica con bioimpedancia: 30 min basales y otros 30 con VNI. Se midieron el gasto cardiaco (GC), el índice cardiaco y el volumen sistólico. Se tomó como referencia el GC calculado para cada paciente expresado como porcentaje sobre su límite inferior de normalidad (LIN) y se establecieron 2 grupos: sin IC con GC conservado (≥ 100% sobre LIN) y con IC y GC bajo (< 100% del LIN). Se utilizaron la U de Mann-Whitney para comparación de variables independientes y el test de Wilcoxon para variables apareadas, se consideró significativo p < 0,05. RESULTADOS: La muestra final fue de 36 casos, de 66 (8) años, 19 (52%) varones. En 17 (46%) detectamos IC con GC de 3,7 l/min (66%) frente al grupo sin IC con 7 l/min (107%). Tras VNI, los pacientes en IC mejoraron su GC (4,5 l/min [77%] p = 0,009) y no lo modificó el grupo sin IC: 6,8 l/min (104%), p = 0,2. CONCLUSIÓN: Un 46% de pacientes con SOH estable presenta IC. La VNI mejora su hemodinámica y no influye en los pacientes con GC conservado

INTRODUCTION: Obesity-hypoventilation syndrome (OHS) is a risk factor for heart failure (HF). Some studies associate the use of non-invasive ventilation (NIV) with changes in hemodynamic parameters. Our objective was to describe the hemodynamic status of a group of patients with OHS and to study the effect of NIV. PATIENTS AND METHODS: Patients with stable OHS treated with NIV were included in this cross-sectional repeated measurements study. Hemodynamics were measured by bioimpedance: 30minutes at baseline and another 30minutes on NIV. Cardiac output (CO), cardiac index, and systolic volume were measured. The CO calculated for each patient expressed as a percentage of the lower limit of normal (LLN) was taken as reference, and 2 groups were formed: patients without HF and normal CO (≥ 100% of LLN) and patients with HF and low CO (< 100% of LLN). The Mann-Whitney U test was used to compare independent variables and the Wilcoxon test was used for paired variables, with significance set at P < .05. RESULTS: The final sample comprised 36 patients, aged 66 (± 8) years, 19 (52%) men. In 17 (46%) patients, HF was detected with a CO of 3.7 l/min (66%) compared to the group without HF, whose CO was 7 l/min (107%). After NIV, patients with HF showed improvement in CO (4.5 l/min (77%), P = .009, while the non-HF group remained unchanged, with CO 6.8 l/min (104%), P = .2. CONCLUSION: A total of 46% of patients with stable OHS present HF; NIV improves hemodynamics and does not affect patients with normal CO

Obesity-Hypoventilation Syndrome: Baseline Hemodynamic Status and Impact of non-Invasive Ventilation. / Síndrome de obesidad-hipoventilación: situación hemodinámica basal e impacto de la ventilación no invasiva.

INTRODUCTION: Obesity-hypoventilation syndrome (OHS) is a risk factor for heart failure (HF). Some studies associate the use of non-invasive ventilation (NIV) with changes in hemodynamic parameters. Our objective was to describe the hemodynamic status of a group of patients with OHS and to study the effect of NIV. PATIENTS AND METHODS: Patients with stable OHS treated with NIV were included in this cross-sectional repeated measurements study. Hemodynamics were measured by bioimpedance: 30minutes at baseline and another 30minutes on NIV. Cardiac output (CO), cardiac index, and systolic volume were measured. The CO calculated for each patient expressed as a percentage of the lower limit of normal (LLN) was taken as reference, and 2 groups were formed: patients without HF and normal CO (≥ 100% of LLN) and patients with HF and low CO (< 100% of LLN). The Mann-Whitney U test was used to compare independent variables and the Wilcoxon test was used for paired variables, with significance set at P<.05. RESULTS: The final sample comprised 36 patients, aged 66 (± 8) years, 19 (52%) men. In 17 (46%) patients, HF was detected with a CO of 3.7 l/min (66%) compared to the group without HF, whose CO was 7 l/min (107%). After NIV, patients with HF showed improvement in CO (4.5 l/min (77%), P=.009, while the non-HF group remained unchanged, with CO 6.8 l/min (104%), P=.2. CONCLUSION: A total of 46% of patients with stable OHS present HF; NIV improves hemodynamics and does not affect patients with normal CO.

Objective and Subjective Sleep Efficiency in Adult Patients with Cystic Fibrosis and Impact on Quality of Life.

INTRODUCTION: Poor sleep quality and excessive daytime sleepiness are common in patients with cystic fibrosis (CF), and both are negatively correlated with health-related quality of life (HRQoL). The objective of our study was to evaluate subjective and objective sleep quality in adult CF patients and its effect on HRQoL. MATERIALS AND METHODS: This was a descriptive, prospective, cross-sectional study of CF patients > 18 years of age. Patients underwent nocturnal polysomnography (PSG) and were administered the Pittsburgh Sleep Quality Index questionnaire (PSQI) and the Cystic Fibrosis Quality of Life Questionnaire (CFQR 14 + Spain). RESULTS: The study included 23 patients, 14 women (61%). The mean age of the participants was 32 + 18 years. The mean PSQI score was 5.57 + 3.55; 13 (56.5%) of the patients were poor sleepers, and 13% reported poor sleep quality; seven (30%) had sleep latency > 30 min, 10 (43.5%) had sleep efficiency < 85%. Nineteen underwent polysomnography. According to PSG measurements, sleep efficiency was less than 90% in 61% of the patients. Pathological values were found for the following parameters: intra-sleep wakefulness in 12 patients (63%); microarousal index in 12 patients (63%); and apnea-hypopnea index (AHI) in 2 patients. The desaturation time with SpO2 < 90% (T90) was > 30% in 3 patients. We observed a significant correlation between PSQI and all dimensions of CFQR 14. CONCLUSIONS: Subjective and objective sleep efficiency decreases in adult CF patients. Sleep quality has an impact on HRQoL. The PSQI questionnaire was able to discriminate sleep quality.

Respuesta a la hipercapnia en pacientes con síndrome obesidad-hipoventilación en tratamiento con ventilación no invasiva en domicilio / Hypercapnia Response in Patients with Obesity-Hypoventilation Syndrome Treated with Non-Invasive Ventilation at Home

Introducción: En la patogenia del síndrome de obesidad-hipoventilación (SOH) se ha postulado una disfunción del centro respiratorio, que muchas veces precisa la utilización de ventilación no invasiva (VNI) en domicilio para el tratamiento. Nuestro objetivo fue medir el efecto de la VNI en la función del CR en pacientes con SOH y los factores que lo determinan. Métodos: Con un diseño prospectivo de mediciones repetidas se estudió la respuesta a la hipercapnia (RHC) midiendo la pendiente de la relación p01/pEtCO2 en situación basal y tras 6meses de tratamiento con VNI en un grupo de pacientes con SOH. Previamente en un grupo control se estableció un umbral en 0,22cmH2O/mmHg para diferenciar la respuesta óptima (RO) de la respuesta subóptima (RSO) del CR. Resultados: Se incluyeron 36 casos, 19 varones (52%), de 65 (DE: 9) años de edad; un 63% de ellos tenían un p01/pEtCO2 por debajo del valor de referencia. El valor basal de p01/pEtCO2 fue de 0,17 (DE: 0,14) cmH2O/mmHg y tras 6meses de VNI fue de 0,30 (DE: 0,22) cmH2O/mmHg (p=0,011). Tras 6meses de tratamiento con VNI, 12 casos (33%) mantienen una función deprimida de su CR. Conclusión: Un 63% de los pacientes con SOH mostraron disfunción de su CR. La aplicación de VNI mejora la función del CR, aunque no en todos los casos

Introduction: Respiratory center (RC) dysfunction has been implicated in the pathogenesis of obesity-hypoventilation syndrome (OHS), and often requires treatment with home non-invasive ventilation (NIV). Our objective was to measure the effect of NIV on RC function in patients with OHS, and the factors that determine such an effect. Methods: We performed a prospective, repeated measures study to evaluate hypercapnia response (HR) by determining the p01/pEtCO2 ratio slope at baseline and after 6months of treatment with NIV in a group of OHS patients. A threshold of 0.22cmH2O/mmHg had previously been established in a control group, in order to differentiate optimal RC response from suboptimal RC response. Results: A total of 36 cases were included, 19 men (52%) aged 65 (SD 9) years, 63% of whom had p01/pEtCO2 below the reference value. Baseline p01/pEtCO2 was 0.17 (SD: 0.14) cmH2O/mmHg and, after 6 months of NIV, 0.30 (SD: 0.22) cmH2O/mmHg (p=0.011). After 6months of treatment with NIV, depressed RC function persisted in 12 cases (33%). Conclusion: In total, 63% of OHS patients had RC dysfunction. The application of NIV improves RC function but not in all cases

Hypercapnia Response in Patients with Obesity-Hypoventilation Syndrome Treated with Non-Invasive Ventilation at Home. / Respuesta a la hipercapnia en pacientes con síndrome obesidad-hipoventilación en tratamiento con ventilación no invasiva en domicilio.

INTRODUCTION: Respiratory center (RC) dysfunction has been implicated in the pathogenesis of obesity-hypoventilation syndrome (OHS), and often requires treatment with home non-invasive ventilation (NIV). Our objective was to measure the effect of NIV on RC function in patients with OHS, and the factors that determine such an effect. METHODS: We performed a prospective, repeated measures study to evaluate hypercapnia response (HR) by determining the p01/pEtCO2 ratio slope at baseline and after 6months of treatment with NIV in a group of OHS patients. A threshold of 0.22cmH2O/mmHg had previously been established in a control group, in order to differentiate optimal RC response from suboptimal RC response. RESULTS: A total of 36 cases were included, 19 men (52%) aged 65 (SD 9) years, 63% of whom had p01/pEtCO2 below the reference value. Baseline p01/pEtCO2 was 0.17 (SD: 0.14) cmH2O/mmHg and, after 6 months of NIV, 0.30 (SD: 0.22) cmH2O/mmHg (p=0.011). After 6months of treatment with NIV, depressed RC function persisted in 12 cases (33%). CONCLUSION: In total, 63% of OHS patients had RC dysfunction. The application of NIV improves RC function but not in all cases.

Determinants of cardiovascular mortality in a cohort of primary care patients with chronic ischemic heart disease. BARBANZA Ischemic Heart Disease (BARIHD) study.

BACKGROUND: Prognosis of chronic patients with established ischemic heart disease (IHD) is not fully understood. The objective was to determine which factors are related to cardiovascular death and hospitalizations in patients with IHD within a primary care network. MATERIALS AND METHODS: A cohort study was carried out by 69 primary care providers in Spain in 2007. Participants were followed up for a mean of 2.2 ± 0.3 years. 1095 patients were recruited if they had established (at least 1 year of known disease) IHD (myocardial infarction or and stable or unstable angina). Several hypothesized determinants of cardiovascular mortality were studied, using Cox proportional hazard regression models. Subgroup analysis was also performed for participants without cardiovascular admissions within the last year. RESULTS: Mean time since first IHD diagnosis was 7.6 ± 6.0 years. Annual all-cause mortality rate was 3.25%, with 44 cardiovascular deaths and 119 cardiovascular admissions. The main prognostic factor for cardiovascular death was previous heart failure (hazard ratio [HR] 4.32, 95% confidence interval [CI] 2.30 to 8.11, p<0.001). Recent cardiovascular admission doubled the risk for death (HR 2.01, CI 1.06 to 3.81, p=0.031). Results showed that use of beta blockers and increased physical activity were the main protective factors. Patients without a recent cardiovascular admission showed previous heart failure as the main significant factor for cardiovascular death. CONCLUSIONS: Patients with chronic IHD in a primary care setting may need a closer follow-up in the presence of previous conditions such as heart failure. Physical activity and treatment with beta blockers were the factors giving these patients the greatest protection.