Antonio Antón

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.

Sleep hypoventilation due to increased nocturnal oxygen flow in hypercapnic COPD patients.

Background and objective:  Several COPD treatment guidelines recommend increasing oxygen flow during sleep to avoid nocturnal desaturation. However, such an increase could have deleterious clinical and gas exchange effects. The objective of this study was to evaluate short‐term gas exchange alterations produced by increasing the nocturnal oxygen flow rate.

Predicting nocturnal hypoventilation in hypercapnic chronic obstructive pulmonary disease patients undergoing long-term oxygen therapy.

Background: Chronic obstructive pulmonary disease (COPD) patients are very sensitive to changes in pulmonary mechanics and central ventilation control during sleep and may develop significant gas exchange alterations with increased hypoxemia and hypercapnia. Oxygen therapy improves nocturnal desaturation but can worsen hypoventilation. Objectives: To analyze the prevalence of nocturnal hypoventilation (NHV) in hypercapnic COPD patients and to determine predictive factors for this phenomenon. Methods: This was a prospective multicenter study which enrolled 80 clinically stable COPD patients with hypercapnic respiratory failure who fulfilled the conventional criteria for long-term oxygen therapy (LTOT). All patients had undergone pulmonary function testing, blood gas analysis, and respiratory polygraphy. Arterial blood gas samples were obtained while patients were awake and during sleep. NHV was considered when an increase in PaCO2 >10 mm Hg was observed in any nocturnal arterial blood gas sample as compared to the awake levels. Results: Seventeen patients (21%) developed NHV. NHV was associated with the values of BMI, hemoglobin, hematocrits, DLCO, and PaO2 reached after oxygen administration. In the logistic regression analysis BMI (OR 1.26, 95% CI 1.068–1.481; p = 0.006) and the diurnal increase of PaO2 after O2 (OR 0.89, 95% CI 0.807–0.972; p = 0.010) were the variables that best discriminated with a sensitivity of 82% and a specificity of 78%. Conclusions: NHV is a relatively common finding in stable hypercapnic COPD patients undergoing LTOT and it is related to a higher BMI and lower PaO2 after oxygen administration.

Atención integral a pacientes con esclerosis lateral amiotrófica: un modelo asistencial

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that presents with muscle weakness, causing progressive difficulty in movement, communication, eating and ultimately, breathing, creating a growing dependence on family members and other carers. The ideal way to address the problems associated with the disease, and the decisions that must be taken, is through multidisciplinary teams. The key objectives of these teams are to optimise medical care, facilitate communication between team members, and thus to improve the quality of care. In our centre, we have extensive experience in the care of patients with ALS through an interdisciplinary team whose aim is to ensure proper patient care from the hospital to the home setting. In this article, we describe the components of the team, their roles and our way of working.

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

Carbon Dioxide Rebreathing in Noninvasive Ventilation

Several factors in noninvasive positive pressure ventilation (NIPPV) have proved to be potential causes of failure when this kind of mechanical respiratory assistance is used in patients who suffer from acute (ARF) or chronic (CRF) respiratory failure [1–3]. One such factor is carbon dioxide (CO2) rebreathing [1–4]. This phenomenon consists of rebreathing part of the CO2 expired by the patient during the ventilatory cycle as a result of an accumulation of this gas in the mask or the circuit. Such rebreathing takes place mainly in single-limb circuits (inspiration and expiration into the same tube). Besides the use of such a circuit, there are technical circumstances that play an active role in the presence or elimination of expired CO2: the ventilatory mode [4, 5], type of mask and expiratory port [6–12], as well as the level of positive end-expiratory pressure (PEEP) used [4, 10, 11]. Since 1995, when Ferguson and his collaborators first described such a phenomenon, little research has been done on this issue. The development of technological innovations, mainly in interfaces, has restricted the potential clinical implications of this deleterious phenomenon. Likewise, research works conducted so far have not confirmed whether CO2 rebreathing does have a significant influence on patients’ clinical evolution or is just a potentially, but rarely, harmful phenomenon.

Acute Confusional Syndrome Associated With Obstructive Sleep Apnea Aggravated by Acidosis Secondary to Oral Acetazolamide Treatment

Acute confusional syndrome, or delirium, is a transitory mental state characterized by the fluctuating alteration of awareness and attention levels. We present the case of a patient with acute confusional syndrome associated with obstructive sleep apnea syndrome (OSAS) aggravated by metabolic acidosis induced by oral acetazolamide treatment.A 70-year-old man with no history of neurological disease was referred with a clinical picture consistent with acute confusional syndrome presenting between midnight and dawn. During the admission examination infectious, toxic, and neurologic causes, or those related to metabolic or heart disease were ruled out. Arterial blood gases measured during one of the nighttime episodes of acute confusional syndrome showed mild hypoxia and hypercapnia with mixed acidosis. Signs and symptoms suggestive of OSAS had been developing over the months prior to admission, with snoring, sleep apnea, and moderate daytime drowsiness. Polysomnography demonstrated severe OSAS with an apnea-hypopnea index of 38. Mean arterial oxygen saturation was 83%; time oxygen saturation remained below 90% was 44%. The attending physician ordered the withdrawal of oral acetazolamide, which was considered the cause of the metabolic component of acidosis. Treatment with continuous positive airway pressure was initiated at 9 cm H2O, after a titration polysomnographic study. The patient continued to improve.OSAS, for which very effective treatment is available, should be included among diseases that may trigger acute confusional syndrome.