M. Mayos

Eficacia de la prueba de los 6 minutos de marcha en la valoración de la oxigenoterapia de deambulación

Objetivo: Comparar la saturacion de la oxihemoglobina (SpO2) observada durante la prueba de los 6 min de marcha (P6m) con la SpO2 de la pulsioximetria ambulatoria realizada durante las actividades de la vida diaria (AVD). Se analizo tambien la eficacia de la P6m en determinar el flujo de oxigeno adecuado para prevenir la desaturacion arterial durante las AVD. Pacientes y metodos: Se estudio a 37 pacientes diagnosticados de enfermedad pulmonar obstructiva cronica --valor medio (± desviacion estandar) del volumen espiratorio forzado en el primer segundo 26 ± 9% del valor de referencia-- en los que se compararon los valores de SpO2 obtenidos en la P6m y la pulsioximetria ambulatoria. De los 20 pacientes con desaturacion al esfuerzo, 11 aceptaron el oxigeno liquido portatil y realizaron la pulsioximetria ambulatoria de forma aleatorizada en 2 dias consecutivos con y sin la administracion de oxigeno. El flujo de oxigeno se establecio en la P6m con pruebas sucesivas hasta lograr una SpO2 media superior al 85%. Resultados: La SpO2 media en el total de pacientes fue del 84 ± 7% en la P6m y del 89 ± 4% en la pulsioximetria ambulatoria (p < 0,001). Los porcentajes de tiempo acumulado con SpO2 < del 90, del 88 y del 85% fueron superiores en la P6m (p < 0,001). Durante la P6m, en un 27% de los pacientes se detecto desaturacion, que no se confirmo con la pulsioximetria ambulatoria. En el subgrupo de 11 pacientes no se observaron diferencias significativas entre la P6m y la pulsioximetria ambulatoria realizadas con el flujo de oxigeno ajustado. Conclusion: La P6m es un metodo eficaz para detectar la desaturacion durante las AVD y establecer el flujo de oxigeno para corregir la desaturacion al esfuerzo.

Resistencia nasal y tratamiento con presión positiva continua en la vía aérea en el síndrome de apnea-hipopnea obstructiva del sueño

Objetivo: Evaluar la relacion de la resistencia nasal (RN) con la tolerancia y el cumplimiento del tratamiento con presion positiva continua en la via aerea (CPAP) en pacientes con sindrome de apnea-hipopnea obstructiva del sueno (SAHS). Material y metodo: Se estudio a 125 pacientes con indice de apneas-hipopneas (IAH) media (desviacion tipica) de 53 ± 21, en tratamiento con CPAP. La RN fue medida antes de iniciar el tratamiento mediante rinomanometria anterior activa, considerando los valores de flujo (ml/s) a 150 Pa de presion en cada fosa nasal. Se valoro la tolerancia y el cumplimiento de la CPAP a las 2 semanas, a los 6 meses y al ano del tratamiento. Resultados: La media de la presion de CPAP prescrita fue de 9 ± 2 cmH2O. En 70 pacientes (56%) se considero que la rinomanometria era patologica. No observamos correlacion entre los flujos nasales y la presion de CPAP establecida (r = 0,018). El cumplimiento objetivo del tratamiento en el primer ano fue de 5 ± 1,5 h/dia. En este periodo, los efectos secundarios nasales mas frecuentes fueron sintomas funcionales, tales como hidrorrinorrea, picor o estornudos (24%), sequedad oronasal (21%) y obstruccion nasal subjetiva (6%). No hubo diferencias significativas en la tolerancia y el cumplimiento de la CPAP entre los pacientes con rinomanometrias normal y patologica. Conclusiones: En el paciente con SAHS, la RN valorada con rinomanometria anterior no se correlaciona con el nivel de presion optima de CPAP y no influye en su tolerancia ni en su cumplimiento.

Efficacy of the 6-Minute Walk Test in Evaluating Ambulatory Oxygen Therapy

OBJECTIVE To compare oxyhemoglobin saturation (SpO2) observed during the 6-minute walk test with that of pulse oximetry carried out during activities of daily living (ADLs). The efficacy of the 6-minute walk test for determining adequate oxygen flow to prevent arterial desaturation during ADLs was also analyzed. PATIENTS AND METHODS We studied 37 patients diagnosed with chronic obstructive pulmonary disease (COPD)--mean (SD) forced expiratory volume in 1 second, 26% (9%) of predicted--and compared SpO2 values obtained in the 6-minute walk test with those obtained with ambulatory pulse oximetry during ADLs. Eleven of the 20 patients with exercise-induced desaturation agreed to use portable liquid oxygen and were randomized to ambulatory pulse oximetry on 2 consecutive days, both with and without the administration of oxygen. Oxygen flow was adjusted on successive 6-minute walk tests until a mean SpO2 greater than 85% was reached. RESULTS The mean SpO2 for all patients was 84% (7%) during the 6-minute walk test and 89% (4%) during ADLs (P<.001). Cumulative percentages of time with SpO2 less than 90%, 88%, and 85% were higher during the 6-minute walk test than during ADLs (P<.001). During the walk test, desaturation was detected in 27% of patients, but was not confirmed by ambulatory pulse oximetry during ADLs. In the subgroup of 11 patients using portable liquid oxygen no significant differences were found between SpO2 values recorded during the walk test and during ADLs with the appropriate oxygen flow. CONCLUSION The 6-minute walk test is an effective method for detecting desaturation during ADLs and for establishing the oxygen flow needed to correct exercise-induced desaturation.

Apnea del sueño en individuos de edad avanzada. Actividad asistencial (2002–2008) en España

INTRODUCTION AND OBJECTIVE There is a significant lack of scientific evidence on the role of SAHS in the elderly despite the increasing ageing of the population. The objective of the present study is to analyse the current healthcare situation in Spain on the diagnosis and treatment of sleep apnea in the population ≥65 years and its progress over the last few years. MATERIAL AND METHOD Cross-sectional study. Healthcare information was collected on the diagnosis and treatment of patients of both sexes and ≥65 years suspected with having SAHS and referred to sleep units (SU) between 2002 and 2008. RESULTS There were 51,229 sleep studies performed in 16 SU. Of these, 24.3% were performed on subjects ≥ 65 years (64.9% males), of which 71.5% had an AHI (apnoea-hypopnoea index) >10 (68.6% treated with CPAP). There were no differences over time as regards mean age, mean AHI or percentage of studies done. A significant decrease was observed in the number of CPAP prescribed to males ≥65 years from 2002 to 2005 (p=0.01) which subsequently increased up to 2008 (p=0.01). This phenomenon was not observed in women ≥65 years. CONCLUSION Despite the lack of evidence on the subject, healthcare activity due to suspected SAHS in the elderly population is intense, therefore it should be a priority to start clinical studies that may be able to answer key questions on the diagnosis and treatment of SAHS in this age group.

Muscle MRI Findings in Childhood/Adult Onset Pompe Disease Correlate with Muscle Function

Objectives Enzyme replacement therapy has shown to be effective for childhood/adult onset Pompe disease (AOPD). The discovery of biomarkers useful for monitoring disease progression is one of the priority research topics in Pompe disease. Muscle MRI could be one possible test but the correlation between muscle MRI and muscle strength and function has been only partially addressed so far. Methods We studied 34 AOPD patients using functional scales (Manual Research Council scale, hand held myometry, 6 minutes walking test, timed to up and go test, time to climb up and down 4 steps, time to walk 10 meters and Motor Function Measure 20 Scale), respiratory tests (Forced Vital Capacity seated and lying, Maximun Inspiratory Pressure and Maximum Expiratory Pressure), daily live activities scales (Activlim) and quality of life scales (Short Form-36 and Individualized Neuromuscular Quality of Life questionnaire). We performed a whole body muscle MRI using T1w and 3-point Dixon imaging centered on thighs and lower trunk region. Results T1w whole body muscle MRI showed a homogeneous pattern of muscle involvement that could also be found in pre-symptomatic individuals. We found a strong correlation between muscle strength, muscle functional scales and the degree of muscle fatty replacement in muscle MRI analyzed using T1w and 3-point Dixon imaging studies. Moreover, muscle MRI detected mild degree of fatty replacement in paraspinal muscles in pre-symptomatic patients. Conclusion Based on our findings, we consider that muscle MRI correlates with muscle function in patients with AOPD and could be useful for diagnosis and follow-up in pre-symptomatic and symptomatic patients under treatment. Take home message Muscle MRI correlates with muscle function in patients with AOPD and could be useful to follow-up patients in daily clinic.

Effects of Ethnicity on the Prevalence of Obstructive Sleep Apnoea in Patients with Acute Coronary Syndrome: A Pooled Analysis of the ISAACC Trial and Sleep and Stent Study

BACKGROUND Obstructive sleep apnoea (OSA) is an emerging risk factor for acute coronary syndrome (ACS). We sought to determine the effects of ethnicity on the prevalence of OSA in patients presenting with ACS who participated in an overnight sleep study. METHODS A pooled analysis using patient-level data from the ISAACC Trial and Sleep and Stent Study was performed. Using the same portable diagnostic device, OSA was defined as an apnoea-hypopnoea index of ≥15 events per hour. RESULTS A total of 1961 patients were analysed, including Spanish (53.6%, n=1050), Chinese (25.5%, n=500), Indian (12.0%, n=235), Malay (6.1%, n=119), Brazilian (1.7%, n=34) and Burmese (1.2%, n=23) populations. Significant differences in body mass index (BMI) were found among the various ethnic groups, averaging from 25.3kg/m2 for Indians and 25.4kg/m2 for Chinese to 28.6kg/m2 for Spaniards. The prevalence of OSA was highest in the Spanish (63.1%), followed by the Chinese (50.2%), Malay (47.9%), Burmese (43.5%), Brazilian (41.2%), and Indian (36.1%) patients. The estimated odds ratio of BMI on OSA was highest in the Chinese population (1.17; 95% confidence interval: 1.10-1.24), but was not significant in the Spanish, Burmese or Brazilian populations. The area under the curve (AUC) for the Asian patients (ranging from 0.6365 to 0.6692) was higher than that for the Spanish patients (0.5161). CONCLUSION There was significant ethnic variation in the prevalence of OSA in patients with ACS. The magnitude of the effect of BMI on OSA was greater in the Chinese population than in the Spanish patients.

Síndrome confusional agudo asociado a apnea-hipopnea obstructiva del sueño y agravado por acidosis metabólica secundaria a acetazolamida oral

El sindrome confusional agudo o delirium es un trastorno transitorio del estado mental caracterizado por la alteracion fluctuante del nivel de conciencia y atencion. Presentamos el caso de un paciente con sindrome confusional agudo asociado a sindrome apnea-hipopnea obstructiva del sueno (SAHOS), agravado por una acidosis metabolica secundaria al tratamiento con acezatolamida. Se trataba de un varon de 70 anos de edad, sin antecedentes de enfermedad neurologica previa, remitido por un cuadro confusional agudo de inicio en la madrugada. Durante el ingreso se descartaron causas de origen infeccioso, toxico, neurologico o secundarias a enfermedad metabolica o cardiaca. Los gases arteriales obtenidos en la madrugada durante uno de los episodios de sindrome confusional agudo mostraron una ligera hipoxia e hipercapnia con acidosis de tipo mixto. El paciente habia presentado en los meses previos al ingreso sintomas indicativos de SAHOS (ronquido, pausas respiratorias durante el sueno y somnolencia diurna moderada). Se efectuo una polisomnografia diagnostica que puso de manifiesto un SAHOS de caracter grave. El indice de apnea-hipopnea/h era de 38, la saturacion de oxigeno media del 83% y el tiempo de saturacion de oxigeno por debajo del 90%, del 44%. Se retiro la acetazolamida oral, que se considero la causa del componente metabolico de la acidosis, y tras un nuevo estudio polisomnografico de titulacion se inicio tratamiento con presion continua en la via aerea a 9 cmH2O. El paciente siguio un curso clinico favorable. El SAHOS, entidad con un tratamiento muy eficaz, ha de incluirse entre las enfermedades que pueden precipitar un sindrome confusional agudo

Cardiac Troponin Values in Patients With Acute Coronary Syndrome and Sleep Apnea: A Pilot Study

Background An analysis of cardiac injury markers in patients with OSA who sustain an episode of acute coronary syndrome (ACS) may contribute to a better understanding of the interactions and impact of OSA in subjects with ACS. We compared peak cardiac troponin I (cTnI) levels in patients with OSA and patients without OSA who were admitted for ACS. Methods Blood samples were collected every 6 hours from the time of admission until two consecutive assays showed a downward trend in the cTnI assay. The highest value obtained defined the peak cTnI value, which provides an estimate of infarct size. Results We included 89 patients with OSA and 38 patients without OSA with an apnea‐hypopnea index of a median of 32 (interquartile range [IQR], 20.8‐46.6/h and 4.8 [IQR, 1.6‐9.6]/h, respectively. The peak cTnI value was significantly higher in patients without OSA than in patients with OSA (median, 10.7 ng/mL [IQR, 1.78‐40.1 ng/mL] vs 3.79 ng/mL [IQR, 0.37‐24.3 ng/mL]; P = .04). The multivariable linear regression analysis of the relationship between peak cTnI value and patient group, age, sex, and type of ACS showed that the presence or absence of OSA significantly contributed to the peak cTnI level, which was 54% lower in patients with OSA than in those without OSA. Conclusions The results of this study suggest that OSA has a protective effect in the context of myocardial infarction and that patients with OSA may experience less severe myocardial injury. The possible role of OSA in cardioprotection should be explored in future studies.

Impact of Obstructive Sleep Apnea on the Levels of Placental Growth Factor (PlGF) and Their Value for Predicting Short-Term Adverse Outcomes in Patients with Acute Coronary Syndrome

Background Placental growth factor (PlGF) induces angiogenesis and promotes tissue repair, and plasma PlGF levels change markedly during acute myocardial infarction (AMI). Currently, the impact of obstructive sleep apnea (OSA) in patients with AMI is a subject of debate. Our objective was to evaluate the relationships between PlGF levels and both the severity of acute coronary syndrome (ACS) and short-term outcomes after ACS in patients with and without OSA. Methods A total of 538 consecutive patients (312 OSA patients and 226 controls) admitted for ACS were included in this study. All patients underwent polygraphy in the first 72 hours after hospital admission. The severity of disease and short-term prognoses were evaluated during the hospitalization period. Plasma PlGF levels were measured using an electrochemiluminescence immunoassay. Results Patients with OSA were significantly older and more frequently hypertensive and had higher BMIs than those without OSA. After adjusting for age, smoking status, BMI and hypertension, PlGF levels were significantly elevated in patients with OSA compared with patients without OSA (19.9 pg/mL, interquartile range: 16.6–24.5 pg/mL; 18.5 pg/mL, interquartile range: 14.7–22.7 pg/mL; p<0.001), and a higher apnea-hypopnea index (AHI) was associated with higher PlGF concentrations (p<0.003). Patients with higher levels of PlGF had also an increased odds ratio for the presence of 3 or more diseased vessels and for a Killip score>1, even after adjustment. Conclusions The results of this study show that in patients with ACS, elevated plasma levels of PlGF are associated with the presence of OSA and with adverse outcomes during short-term follow-up. Trial Registration ClinicalTrials.gov NCT01335087

Influencia del volumen pulmonar y de la posición corporal en las presiones respiratorias estáticas máximas

Para valorar la influencia del volumen pulmonar y de la posicion corporal en la determinacion de la presiones respiratorias estaticas maximas (P I max, P E max), se estudio un grupo de 30 voluntarios sanos con funcion pulmonar normal. La P I max se midio desde el volumen residual (RV) y la capacidad residual funcional (FRC) y la P E max desde la capacidad pulmonar total (TLC) y FRC. Todas las mediciones se efectuaron en posicion sentada y en decubito supino, en orden aleatorio. Las determinaciones en posicion sentada fueron significativamente superiores a las del decubito (p I -maxRV y FRC en decubito correspondieron a un 87(12) % y 92(17) % de los valores respectivos obtenidos en posicion sentada. Las P E maxTLC y FRC en decubito fueron de 93(15) % y 92(19) % de las respectivas en posicion sentada. La P I maxRV fue superior (p I maxFRC solo en posicion sentada, mientras que la P E maxTLC fue superior (p E maxFRC en ambas posiciones. Asi pues, las posiciones y los volumenes estudiados influyen significativamente en la determinacion de las presiones respiratorias estaticas maximas, por lo que ambos factores deben tenerse en cuenta para la correcta interpretacion de los resultados.