[Significance of oxygen hyperventilation in bronchofiberscopy in intensive medicine]

In 25 patients (group I = 15 patients, group II = 10 patients) we examined the influence of bronchoscopic aspiration on lung function. PaO2 and PaCO2 were measured before, during, and after bronchoscopic aspiration. In all cases the insertion of the bronchofiberscope was performed by means of a transnasal tube. In 15 patients of Group I an increase in PaO2 followed, and because of this we could reduce FiO2 after bronchoscopic examination. The 10 patients of Group II were hyperventilated before and during the examination (AMV = 150 ml/kg body weight, FiO2 = 1.0). Hyperventilation increased in 10 patients the PaO2 from 53 (43-121) mmHg to 112 (96-225) mmHg. During bronchoscopy PaO2 decreased from 154 (96-225) mmHg to 102 (70-196) mmHg in 8 of the 10 patients. Two patients showed an increase in PaCO2. A third patient had an obvious increase in PaCO2 from 53 to 65 mmHg. Only 24 hours later we observed normalization of PaCO2 and an increase in PaO2. According to these results, hyperventilation (FiO2 = 1.0) during bronchoscopic examination is necessary in intensive care patients. Insertion of the bronchoscope should be performed via tracheal tube. Strict monitoring is imperative.