[The validation of a portable 3-channel recording system (Oxyflow, Edentec) for the diagnosis of the sleep apnea syndrome]. / Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño.

OBJECTIVE: To evaluate the usefulness of a portable recording device (Oxyflow, EdenTec) to measure oronasal airflow, oxygen saturation and arterial pulse for diagnosing sleep apnea syndrome (SAS) using conventional polysomnography as the gold standard. METHODS: Sixty-two subjects suspected of having SAS were studied prospectively by simultaneously recording conventional polysomnography and Oxyflow data in the sleep laboratory. Two different investigators, blinded to each other's findings, interpreted the data from each method. The apnea-hypopnea index (AHI) cut-off points used were?? 10, 15 and 30. The sensitivity, specificity, positive predictive value and negative predictive value of the Oxyflow indices for each AHI cut-off point were calculated. Both computer-generated and manually collected data from the Oxyflow device were analyzed. Manual readings were recorded by two independent investigators and interobserver agreement was calculated. The usefulness of both automatic and manual analyses for SAS diagnosis was assessed using receiver operating characteristic curves (ROC). RESULTS: Fifty-eight (93.5%) men and 4 (6.5%) women with a mean age (+/- SD) of 53 +/- 11 years (29-73) were enrolled. An AHI > or = 10 was observed in 58% of the patients and mean AHI was 25 +/- 28 (0-125). The index of respiratory disturbance per hour of analysis with desaturation events > or = 4% (RDI4%) was the parameter with the largest area under the ROC curve (0.90 for AHI > or = 10; 0.94 for AHI > or = 15 and 0.96 for AHI > or 30). Manual reading was practical and reproducible (agreement 0.93, kappa coefficient 0.82) but its efficiency was no greater than that of automatic analysis. CONCLUSIONS: The Oxyflow device may be a useful diagnostic tool for SAS. Its portability and simplicity makes it potentially useful for in-home studies.

Validación de un sistema portátil de registro de tres canales (Oxyflow, Edentec) para el diagnóstico del síndrome de apnea del sueño / Validation of a portable three-channel recording system (Oxyflow, EdenTec) for diagnosing sleep apnea syndrome

Objetivo: Evaluar la utilidad de un sistema de registro portátil (Oxyflow, Edentec), que mide flujo nasobucal, saturación de oxígeno y pulso arterial, para el diagnóstico del síndrome de apnea del sueño (SAS), utilizando la polisomnografía convencional como patrón de referencia. Métodos: Se estudiaron prospectivamente 62 sujetos con sospecha de SAS, realizándose simultáneamente polisomnografía convencional y registro con Oxyflow en el laboratorio de sueño. Dos investigadores diferentes interpretaron los registros de cada uno de los métodos, a ciegas respecto al otro. Se utilizaron diferentes puntos de corte para el índice de apneas-hipopneas (IAH) (>= 10, 15 y 30). Se calcularon la sensibilidad, especificidad, valor predictivo positivo y valor predicto negativo de los índices del Oxyflow para cada punto de corte del IAH. Al analizar los registros del Oxyflow, se emplearon tanto datos generados por el software incluido en el sistema como los obtenidos con una interpretación manual de los mismos. El análisis manual fue realizado por dos investigadores independientes, y se calculó la concordancia interobservador. La utilidad del análisis manual y el automático para el diagnóstico del SAS fue evaluado usando curvas receptor-operador (ROC). Resultados: Se incluyeron en el estudio 58 varones (93,5 por ciento) y 4 mujeres (6,5 por ciento), con una edad media (ñ DE) de 53 ñ 11 años (29-73). El 58 por ciento de los pacientes tenían un IAH >= 10 (IAH medio: 25 ñ 28 [0-125]). De todos los parámetros analizados, el RDI4 por ciento (índice de episodios respiratorios por hora de registro, con desaturaciones >= 4 por ciento) presentó el mayor área bajo la curva ROC (0,90 para IAH >= 10; 0,94 para IAH >= 15 y 0,96 para IAH >= 30). El análisis manual fue factible y reproducible (concordancia: 0,93; coeficiente kappa: 0,82), pero su eficiencia no fue mayor que la del análisis automático. Conclusiones: El sistema Oxyflow puede ser una herramienta útil para el diagnóstico del SAS. Su portabilidad y simplicidad lo hacen potencialmente útil para estudios domiciliarios. (AU)

The association between sleep apnea and the risk of traffic accidents. Cooperative Group Burgos-Santander.

BACKGROUND AND METHODS: Drowsiness and lack of concentration may contribute to traffic accidents. We conducted a case-control study of the relation between sleep apnea and the risk of traffic accidents. The case patients were 102 drivers who received emergency treatment at hospitals in Burgos or Santander, Spain, after highway traffic accidents between April and December 1995. The controls were 152 patients randomly selected from primary care centers in the same cities and matched with the case patients for age and sex. Respiratory polygraphy was used to screen the patients for sleep apnea at home, and conventional polysomnography was used to confirm the diagnosis. The apnea-hypopnea index (the total number of episodes of apnea and hypopnea divided by the number of hours of sleep) was calculated for each participant. RESULTS: The mean age of the participants was 44 years; 77 percent were men. As compared with those without sleep apnea, patients with an apnea-hypopnea index of 10 or higher had an odds ratio of 6.3 (95 percent confidence interval, 2.4 to 16.2) for having a traffic accident. This relation remained significant after adjustment for potential confounders, such as alcohol consumption, visual-refraction disorders, body-mass index, years of driving, age, history with respect to traffic accidents, use of medications causing drowsiness, and sleep schedule. Among subjects with an apnea-hypopnea index of 10 or more, the risk of an accident was higher among those who had consumed alcohol on the day of the accident than among those who had not. CONCLUSIONS: There is a strong association between sleep apnea, as measured by the apnea-hypopnea index, and the risk of traffic accidents.

[Hepatic hydrothorax without ascites: presentation of a case and review of the literature]. / Hidrotórax hepático sin ascitis: presentación de un caso y revisión de la literatura.

Hepatic Hydrothorax is a well known complication in patients with cirrhosis and secondary ascites. It is unusual in the absence of ascites, with few cases reported in the literature. We describe a patient with Hepatic Hydrothorax without ascites and review the literature.

[Spontaneous pneumothorax associated with human immunodeficiency virus (HIV) infection]. / Neumotórax espontáneo asociado a la infección por el virus de la inmunodeficiencia humana (VIH).

Spontaneous pneumothorax is a relatively frequent complication of human immunodeficiency virus (HIV) infection. Seven hundred sixty-five HIV-infected inpatients were treated at Marques de Valdecilla University Hospital between 1990 and 1996. Spontaneous pneumothorax developed in 9 patients. Pneumocystis carinii pneumonia was diagnosed in 6 patients (66%), either before or simultaneous to the appearance of pneumothorax. Pneumothorax was related to active or old tuberculosis infection in 3 patients (33%). Prophylactic therapy with nebulized pentamidine was used in 55% of the patients. Successful initial control of pneumothorax was achieved with simple drains in 58% of the episodes, although the recurrence rate was 71%. Pleurodesis with talcum with a chest tube was used successfully in 3 patients, in 2 because of sings of persistent air leakage uncorrected by simple drainage. Pleurodesis initially failed but later controlled pneumothorax the second time it was used. The mortality rate in this series was 66%, with a mean survival time of 55.6 days. We conclude that spontaneous pneumothorax is associated with poor prognosis in HIV infected patients. Prior or concurrent P. carinni pneumonia or tuberculosis were the etiologic factors identified in our patients. A simple pleural drain was associated with a high rate of recurrence, such that pleurodesis seems warranted in all patients.

[Small cell lung carcinoma in the form of multiple lung nodules]. / Carcinoma pulmonar de células pequeñas en forma de nódulos pulmonares múltiples.

Small cell carcinoma of the lung occasionally presents as a single pulmonary nodule, but its expression in the form of multiple pulmonary nodules has not been reported in the literature. We describe a single case of small cell carcinoma of the lung presenting as multiple pulmonary nodules that seems to have been cured by chemotherapy.

[Measurement of pulmonary function in laryngectomized patients]. / Medición de la función pulmonar en pacientes laringectomizados.

Comparative study upon clinic, radiological and spirometric parameters in 30 laryngectomees, which were spirometric tested by means of a device either simple, cheap, speed and efficient, designed by the AA. These are the conclusions drown out: 1st. There is a poor correlation clinic-functional in patients with obstructive pathology (which command, in the AA's opinion an exploration of the respiratory function in all laryngectomees). 2nd. On the contrary, there are a good radiological and functional correlation in patients suffering for restrictive disease (here the assessment functional means the quantification of the restrictive process). And 3rd. The laryngectomees show a higher functional affectation and can be expected if related to the age and sex. The explanation is to be found in the intercurrent diseases and also in the infections following the larynx removal.