[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.

[Varicella pneumonia in the previously healthy adult]. / Neumonía varicelosa en el adulto previamente sano.

Varicella (chickenpox) is a contagious, self-limited, usually benign disease common in childhood but uncommon in adulthood. Pneumonia is the most frequent complication of the disease in adults. We retrospectively review 7 cases of varicella pneumonia in previously healthy adults diagnosed in our hospital between 1992 and 1996. All of them were treated with intravenous acyclovir with good therapeutic response save for a patient who developed respiratory insufficiency and died 8 days after his admission. Smoking was the only risk factor detected. Clinical features of our patients are described and the need of an early diagnosis and treatment of varicella pneumonia is emphasized.