[Importance of routine examinations in patients with obstructive sleep apnea syndrome]

In patients with obstructive sleep apnea syndrome (OSAS) there is an increased comorbidity of internal diseases such as hypertension, coronary heart disease, chronic obstructive pulmonary disease and endocrine diseases. We analyzed prospectively frequency and consequences of pathological results in routine examinations of internal medicine in sleep laboratory.

250 patients with OSAS underwent routine bodyplethysmography, blood- gas analysis, electrocardiogram and laboratory studies after anamnesis and clinical examination. Prior to this we indicated, whether we based on history and physical examination deemed any of these examinations necessary. Frequency and kind of pathological results as well as the consequences were analyzed.

129 results of bodyplethysmography and blood-gas analysis were pathological (51.6 % of all investigations), most frequently hypoxemia (22 %) and obstructive pattern (16.4 %). Further steps were necessary in 19 patients (7.6 %); the indication was seen before in 13 patients, therefore 6 results with consequences (2.4 %) were not expected. Laboratory studies were abnormal in 133 patients (53.2 % of all investigations), most of them hyperglycaemia (26.8 %) and elevated liver enzymes (20.4 %). 29 results (11.6 %) had consequences, of which 16 (6.4 %) were not expected. 82 electrocardiograms were pathological (32.8 % of all investigations), presenting most frequently as coronary heart disease (21.2 %). Further steps were necessary in 5 patients (2 %), while that was not expected in 3 patients (1.2 %).

Routine examinations of internal medicine in patients with OSAS frequently present pathological results, which seldom have further consequences. As most of the important results can be predicted by history and clinical investigation, pathological by chance diagnoses are rare. With the exception of blood sugar tests routine examinations for patients with OSAS should be considered critically.