Validation of the Hungarian version of the SRI Questionnaire.

BACKGROUND: Home mechanical ventilation is a reliable treatment for patients suffering from chronic respiratory failure, improving survival and quality of life. Prevalence has been increasing worldwide as a result of evolving technical possibilities, telemedicine and improving national guidelines. Projects to establish a national guideline and registry for patients treated with home mechanical ventilation are currently under way in Hungary and our aim was to validate a quality of life questionnaire suited for evaluation and follow up in this specific patient group. The Severe Respiratory Insufficiency Questionnaire (SRI) is a quality of life tool designed to evaluate patients receiving home mechanical ventilation and has been validated both in patient groups receiving invasive and noninvasive ventilation. METHODS: The Hungarian version of the SRI was created using the translation-backtranslation method, which was then tested for validity, viability and reliability in a cohort involving patients from three centers, receiving long-term home mechanical ventilation for chronic respiratory failure through an invasive or noninvasive interface. Patient data was collected (demographic data, lung function test, arterial blood gas, ventilation settings) and quality of life was measured with the previously validated SF-36 and newly created Hungarian SRI Questionnaires at two time points. RESULTS: One hundred four patients receiving home mechanical ventilation were enrolled. The time to complete the SRI Questionnaire was 8.6 (±3.1) minutes, 69.2% questionnaires were self-administered. Exploratory factor analysis explained 73.8% of the variance of the questionnaire, but resulted in 13 scales. We found correlations between the SRI subscale scores to corresponding scales of the previously validated general quality of life survey SF-36. The Cronbach alpha coefficient was 0.928 for the Summary Scale of the SRI Questionnaire, proving high internal consistency. Reproducibility was high for most scales, resulting in a high overall correlation for the summary score (0.877, p < 0.001). CONCLUSIONS: The Hungarian version of the SRI Questionnaire is a viable, valid, reliable and reproduceable quality of life tool applicable for patients treated with home mechanical ventilation.

Hyperviscosity as a possible cause of positive acoustic evoked potential findings in patients with sleep apnea: a dual electrophysiological and hemorheological study.

OBJECTIVE: To test the hypothesis that blood hyperviscosity could account for the controversial results observed during electrophysiological evaluation of the brain stem in sleep apnea syndrome. METHODS: This was a prospective study of a sample of patients with sleep apnea who were participating in a stroke prevention evaluation. Participants were 610 male patients with obstructive sleep apnea, aged 30-55 years, without large vessel disease on Magnetic Resonance Angiography and neck Doppler sonography, and an infratentorial lesion on head magnetic resonance imaging. Brainstem auditory-evoked potential and hemorheological investigations were carried out. RESULTS: Forty-six percent (N=282) of the patients evidenced hyperviscosity and 53% (N=328) had normal rheological findings. Evoked potential changes appeared only in the hyperviscosity positive subgroup. Of these, 84% (N=239) evidenced BAEP changes with 24% (N=57) demonstrating sensorineuronal and 76% (N=182) demonstrating brain stem type abnormalities. After six months of CPAP therapy, hyperviscosity was normalized in 66% (N=159) of patients. BAEP wave III latency values were normalized in 70% (N=112) of these patients. CONCLUSIONS: Viscosity changes play an important role in the brainstem electrophysiological abnormalities in apnea patients. These abnormalities can be normalized after six months of CPAP therapy.