Miguel Carrera

Effects of obesity upon genioglossus structure and function in obstructive sleep apnoea

Obesity is a common feature of the obstructive sleep apnoea syndrome. It can influence the structure and function of skeletal muscles. However, its effects upon the upper airway muscles have not been explored directly. This study assessed the structure and function of the genioglossus in patients with obstructive sleep apnoea syndrome and in healthy subjects (with and without obesity, defined by a body mass index >30 kg·m−2). Further, to investigate the effects of continuous positive airway pressure (CPAP) treatment, patients with obstructive sleep apnoea syndrome after at least 1 yr under CPAP were also studied. The study found that obese and nonobese patients showed different in vitro geniglossus endurance properties. In obese patients, geniglossus endurance was indistinguishable from normal while, nonobese patients, at diagnosis, showed increased genioglossus fatigability; this was not observed in patients treated with CPAP. By contrast, patients with obstructive sleep apnoea syndrome showed at diagnosis a higher percentage of type II fibres than controls and patients under CPAP treatment independently of obesity. This difference is mainly due to a predominance of subtype IIb fibre. This difference was not observed in the group of patients treated with CPAP. Genioglossus twitch force was normal in all patients. These results suggest that different pathogenic mechanisms may underlie the development of obstructive sleep apnoea syndrome in obese and nonobese patients. This observation may have potential clinical implications.

Free fatty acids and the metabolic syndrome in patients with obstructive sleep apnoea

Obesity and metabolic syndrome (MS) occur frequently in patients with obstructive sleep apnoea syndrome (OSAS). We hypothesised that circulating free fatty acids (FFAs) are elevated in OSAS patients independently of obesity. This elevation may contribute to the development of MS in these patients. We studied 119 OSAS patients and 119 controls. Participants were recruited and studied at sleep unit of our institution (Hospital Universitari Son Dureta, Palma de Mallorca, Spain) and were matched for sex, age and body mass index (BMI). The occurrence of MS was analysed by clinical criteria. Serum levels of FFAs, glucose, triglycerides, cholesterol, high-density lipoprotein–cholesterol, aspartate aminotransferase, alanine aminotransferase, &ggr;-glutamyltransferase, C-reactive protein and 8-isoprostanes were determined. Prevalence of MS was higher in OSAS than in the control group (38 versus 21%; p = 0.006). OSAS patients had higher FFAs levels than controls (mean±sd 12.2±4.9 versus 10.5±5.0 mg·dL−1; p = 0.015). Among subjects without MS, OSAS patients (OSAS+ MS-) showed higher levels of FFAs than controls (OSAS- MS-) (11.6±4.7 versus 10.0±4.4 mg·dL−1; p = 0.04). In a multiple regression model, after adjustment for age, sex, BMI and the presence of MS, FFAs were significantly associated with apnoea/hypopnoea index (p = 0.04). This study shows that FFAs are elevated in OSAS and could be one of the mechanisms involved in the metabolic complications of OSAS.

A controlled trial of noninvasive ventilation for chronic obstructive pulmonary disease exacerbations

PURPOSE This prospective, multicenter, double-blind, placebo-controlled study tested the hypothesis that noninvasive positive pressure ventilation reduces the need for endotracheal intubation in patients hospitalized in a pulmonary ward because of acute exacerbation of chronic obstructive pulmonary disease. MATERIALS AND METHODS Seventy-five consecutive patients with exacerbation (pH, 7.31 +/- 0.02; Pao(2), 45 +/- 9 mm Hg; Paco(2), 69 +/- 13 mm Hg) were randomly assigned to receive noninvasive ventilation or sham noninvasive ventilation during the first 3 days of hospitalization on top of standard medical treatment. RESULTS The need for intubation (according to predefined criteria) was lower in the noninvasive ventilation group (13.5% vs 34%, P < .01); in 31 patients with pH not exceeding 7.30, these percentages were 22% and 77%, respectively (P < .001). Arterial pH and Paco(2) improved in both groups, but changes were enhanced by noninvasive ventilation. Length of stay was lower in the noninvasive ventilation group (10 +/- 5 vs 12 +/- 6 days, P = .06). In-hospital mortality was similar in both groups. CONCLUSIONS These results demonstrate that noninvasive positive pressure ventilation, in a pulmonary ward, reduces the need for endotracheal intubation, particularly in the more severe patients, and leads to a faster recovery in patients with acute exacerbation of chronic obstructive pulmonary disease.

Effectiveness of three sleep apnea management alternatives.

RATIONALE Home respiratory polygraphy (HRP) may be a cost-effective alternative to polysomnography (PSG) for diagnosis and treatment election in patients with high clinical probability of obstructive sleep apnea (OSA), but there is conflicting evidence on its use for a wider spectrum of patients. OBJECTIVES To determine the efficacy and cost of OSA management (diagnosis and therapeutic decision making) using (1) PSG for all patients (PSG arm); (2) HRP for all patients (HRP arm); and (3) HRP for a subsample of patients with high clinical probability of being treated with continuous positive airway pressure (CPAP) and PSG for the remainder (elective HRP arm). METHODS Multicentric study of 366 patients with intermediate-high clinical probability of OSA, randomly subjected to HRP and PSG. We explored the diagnostic and therapeutic decision agreements between the PSG and both HRP arms for several HRP cutoff points and calculated costs for equal diagnostic and/or therapeutic decision efficacy. RESULTS For equal diagnostic and therapeutic decision efficacy, PSG arm costs were 18% higher than HRP arm costs and 20% higher than elective HRP arm costs. HRP arm costs tended to be lower than elective HRP arm costs, and both tended to be lower than PSG arm costs if patient costs were omitted. CONCLUSION Home respiratory polygraphy is a less costly alternative than polysomnography for the diagnosis and therapeutic decision making for patients with suspected obstructive sleep apnea. We found no advantage in cost terms, however, in using home respiratory polygraphy for all patients or home respiratory polygraphy for the most symptomatic patients and polysomnography for the rest.

Tratamiento hospitalario de los episodios de agudización de la EPOC. Una revisión basada en la evidencia

Este artículo presenta una visión integrada del tratamiento de los pacientes hospitalizados por agudización de enfermedad pulmonar obstructiva crónica (AEPOC)1-5, basada en la mejor evidencia médica disponible (tabla I). El tratamiento hospitalario de la AEPOC persigue varios objetivos2,5: a) la estabilización respiratoria y hemodinámica del paciente; b) la mejoría o, si es posible, normalización del estado clínico basal del paciente; c) el diagnóstico de la(s) causa(s) de la AEPOC; d) la evaluación de la gravedad de la EPOC y la identificación de cualquier posible comorbilidad presente; e) la educación del paciente en el correcto uso de la medicación y los equipos terapéuticos (nebulizadores, inhaladores, oxigenoterapia, etc.), así como la promoción de un estilo de vida saludable antes del alta, y f) por último, la evaluación de la necesidad de tratamiento adicional en el domicilio, como rehabilitación respiratoria y/u oxigenoterapia domiciliaria. La consecución de estos objetivos requiere el manejo del paciente en diferentes niveles asistenciales del hospital: área de urgencias, sala de hospitalización, unidad de cuidados intensivos (UCI). En esta revisión se abordarán: a) el manejo clínico inicial del paciente con AEPOC en el área de urgencias; b) los criterios de ingreso hospitalario; c) el tratamiento de la AEPOC en la sala de hospitalización convencional; d) el manejo de la AEPOC en la UCI, y e) los criterios de alta desde cada uno de estos niveles asistenciales. Tras ello, se identificarán los aspectos que a juicio de los autores no están resueltos y precisan más investigación.

Resultados de la actuación de una unidad de control de la oxigenoterapia domiciliaria

Objetivo Este estudio pretende: a) analizar la prevalencia de la oxigenoterapia domiciliaria en Mallorca; b) evaluar la relacion coste-beneficio de la unidad de oxigenoterapia, y c) describir la supervivencia de los pacientes con enfermedad pulmonar obstructiva cronica que reciben oxigenoterapia domiciliaria en la actualidad. Metodo En abril de 1994, al crearse la unidad de oxigenoterapia, se evaluaron todos los pacientes que recibian oxigenoterapia domiciliaria en Mallorca (estudio transversal). Durante los 3 anos siguientes, se ha seguido periodicamente a todos aquellos en los que se mantuvo la prescripcion de oxigenoterapia domiciliaria y se han evaluado todas las nuevas prescripciones (estudio longitudinal). Resultados Antes de la puesta en marcha de la unidad de oxigenoterapia, la prevalencia de oxigenoterapia domiciliaria en Mallorca era de 71/100.000 habitantes. Se retiro la oxigenoterapia domiciliaria al 31% de los pacientes evaluados en el estudio transversal. Al finalizar el estudio longitudinal la prevalencia de oxigenoterapia domiciliaria era 56/100.000 habitantes. La actuacion de la unidad de oxigenoterapia ha supuesto un ahorro aproximado de 38 millones de pesetas anuales. Ha aumentado el numero de pacientes con concentrador, que se ha convertido en la principal forma de administracion, y oxigeno liquido. La supervivencia de los pacientes con enfermedad pulmonar obstructiva cronica tratados con oxigenoterapia domiciliaria evaluados en este estudio parece superior a la referida clasicamente. Conclusiones a) La prevalencia de la oxigenoterapia domiciliaria en Mallorca antes de que la unidad de oxigeno-terapia iniciase su actividad era excesivamente alta; b) el analisis coste-beneficio de la actuacion de la unidad de oxigenoterapia es muy positivo porque ha optimizado la prescripcion de oxigenoterapia domiciliaria y ha supuesto un ahorro economico importante (~38 millones de ptas./ano), y c) la supervivencia de los pacientes con enfermedad pulmonar obstructiva cronica que reciben oxigenoterapia domiciliaria en la actualidad parece mejor que la referida clasicamente, posiblemente en relacion con la mayor eficacia de los tratamientos actuales.

Association Between Obstructive Sleep Apnea and Pulmonary Embolism

OBJECTIVES To compare the prevalence of obstructive sleep apnea (OSA) in patients with pulmonary embolism (PE) with a sex-, age-, and body mass index (BMI)-matched, population-based control group and to assess the association between OSA and PE. METHODS We performed a case-control study from October 1, 2006, through November 30, 2009. We included 107 patients with PE and a control group (n=102) without PE in University Hospitals Son Espases and La Paz in Spain. Variables included in the analysis were medical history, anthropometric variables (weight, height, BMI, and neck circumference), Epworth Sleepiness Scale score, home respiratory polygraphy, basic biochemical profile and hemogram, spirometry, and physical activity. RESULTS The mean ± SD apnea-hypopnea index (AHI) was significantly higher in patients with PE than population controls (21.2±20.6 vs 11.5±15.9 h(-1); P<.001). The presence of an AHI greater than 5 h(-1) and hypersomnolence (Epworth Sleepiness Scale score ≥11) was more frequent in PE patients than in controls (14.0% vs 4.9%; P=.0002). A crude model analysis by several cutoffs revealed that the AHI was significantly associated with PE. After adjustment for age, sex, smoking, BMI, lung function, and all known PE risk factors, the odds ratio for PE was 3.7 (95% CI, 1.3-10.5; P=.01). CONCLUSION A higher prevalence of OSA was detected in patients diagnosed as having acute PE than controls. This study identified a significant and independent association between OSA and PE.

Actividad de una unidad de cuidados respiratorios intermedios dependiente de un servicio de neumología

BACKGROUND AND OBJECTIVE With the development of noninvasive ventilation (NIV), patients with increasingly complex needs have been admitted to respiratory medicine departments. For this reason, such departments in Spain and throughout Europe have been adding specialized respiratory intermediate care units (RICUs) for monitoring and treating patients with severe respiratory diseases. The aim of the present study was to describe the activity of such a RICU. The description may be of use in facilitating the setting up of RICUs in other hospitals of the Spanish National Health Service. METHODS A systematic record of activity carried out in the RICU of the Hospital Universitario Son Dureta between January and December 2006 was kept prospectively. RESULTS Of 206 patients with a mean (SD) age of 65 (14) years admitted to the unit, 67% came from the emergency department, 14% from the respiratory medicine department, and 12% from the intensive care unit (ICU). The most common admission diagnoses were exacerbated chronic obstructive pulmonary disease (COPD) (n=97, 47.1%), pneumonia (n=39, 18.9%), heart failure (n=17, 8.2%), and pulmonary vascular diseases (n=18, 8.7%). One hundred twenty-one patients (59%) required NIV. Mean length of stay in the RICU was 5 (5) days. Patients were discharged to the conventional respiratory ward in 79.1% of the cases; 7.8% required subsequent admission to the ICU, and 9.7% died. Of the patients with exacerbated COPD (mean age, 66.5 [10] years; mean length of stay, 4.6 [4.5] days), 67% required NIV, 7.2% required subsequent admission to the ICU, and 8.2% died. CONCLUSIONS The creation of a RICU by a respiratory medicine department is viable in Spain. Such units make it possible to treat a large number of patients with a low rate of therapeutic failures. Exacerbated COPD was the most common diagnosis on admission to our RICU, and the need for NIV the most common criterion for admission.

Significance of Including a Surrogate Arousal for Sleep Apnea-Hypopnea Syndrome Diagnosis by Respiratory Polygraphy

RATIONALE Respiratory polygraphy is an accepted alternative to polysomnography (PSG) for sleep apnea/hypopnea syndrome (SAHS) diagnosis, although it underestimates the apnea-hypopnea index (AHI) because respiratory polygraphy cannot identify arousals. OBJECTIVES We performed a multicentric, randomized, blinded crossover study to determine the agreement between home respiratory polygraphy (HRP) and PSG, and between simultaneous respiratory polygraphy (respiratory polygraphy with PSG) (SimultRP) and PSG by means of 2 AHI scoring protocols with or without hyperventilation following flow reduction considered as a surrogate arousal. METHODS We included suspected SAHS patients from 8 hospitals. They were assigned to home and hospital protocols at random. We determined the agreement between respiratory polygraphy AHI and PSG AHI scorings using Bland and Altman plots and diagnostic agreement using receiver operating characteristic (ROC) curves. The agreement in therapeutic decisions (continuous positive airway pressure treatment or not) between HRP and PSG scorings was done with likelihood ratios and post-test probability calculations. RESULTS Of 366 randomized patients, 342 completed the protocol. AHI from HRP scorings (with and without surrogate arousal) had similar agreement with PSG. AHI from SimultRP with surrogate arousal scoring had better agreement with PSG than AHI from SimultRP without surrogate arousal. HRP with surrogate arousal scoring had slightly worse ROC curves than HRP without surrogate arousal, and the opposite was true for SimultRP scorings. HRP with surrogate arousal showed slightly better agreement with PSG in therapeutic decisions than for HRP without surrogate arousal. CONCLUSION Incorporating a surrogate arousal measure into HRP did not substantially increase its agreement with PSG when compared with the usual procedure (HRP without surrogate arousal).

[Hospital treatment of chronic obstructive pulmonary disease exacerbations: an evidence-based review].

This article presents an integrated overview of treatment of patients admitted to hospital for chronic obstructive pulmonary disease (COPD) exacerbations,1-5 based on the best scientific evidence available (Table 1). Hospital treatment of COPD exacerbations has several aims,2,5 namely: a) to stabilize the patient’s respiration and hemodynamics; b) to improve or, if possible, normalize the clinical state of the patient; c) to diagnose the cause or causes of the exacerbation; d) to assess the severity of COPD and identify other concurrent diseases; e) to educate the patient on how to take medication and use therapeutic equipment (nebulizers, inhalers, oxygen therapy devices, etc) correctly, and to promote a healthy lifestyle before discharge; and, finally, f) to evaluate the need for additional home treatment such as respiratory rehabilitation and/or home oxygen therapy. If these aims are to be achieved, the patient must be managed at different levels of care, that is, in the emergency room, the hospital ward, and the intensive care unit (ICU). This review will cover the following: a) initial clinical management of patients with COPD exacerbations in the emergency room; b) the criteria for admission to hospital; c) treatment for COPD exacerbations in a conventional hospital ward; d) management of COPD exacerbations in the ICU; and e) the criteria for discharge from each of these levels of care. We will then identify aspects that we consider unresolved and in need of further investigation.