1988 Volume 10 Issue 1 Pages 44-49
The influence of examination by flexible fiberoptic bronchoscopy on respiratory function and gas exchange were observed in 33 cases of respiratory diseases. These cases were divided into three groups according to the type of examination procedure. Group A included 9 cases in which only observation, transbronchial lung biopsy or transbronchial brushing were performed. Group B included 15 cases in which bronchoalveolar lavage(BAL) was carried out using more than 50ml of physiological saline. Group C included 9 cases of bronchography(BG) using 15-30ml of radiological opaque contrast medium. The three groups were premedicated with atropine sulphate and local anesthesia with lidocaine before the fiberoptic bronchoscopy examination, and were measured the respiratory function and arterial blood gas values before and after the examination. No significant change in respiratory function was seen in group A. In spite of a reduction in VC, FEV1.0% and V25 were improved in group B. These findings might suggested a decrease in pulmonary compliance, due to washing out of the surfactant from the alveolar wall with physiological saline infusion and remaining BAL fluid in the alveolar space. In group C, VC and FEV1.0 were significantly decreased, and FEV1.0% and peak flow rate were also reduced. The latter findings might suggest air flow obstruction in the bronchial trees. PaO_2 was significantly reduced in all groups, especially groups B and C. There was no change in PaO_2. The changes of PaO_2 significantly correlated to changes in VC between before and after the procedure in group A and C. However, no correlation was found in group B. The changes of PaO_2 and FEV1.0 were significantly correlated in group C. The causes of hypoxemia during fiberoptic bronchoscopy in group B suggested a decrease in lung compliance and VA] Q ratio, and/or shunt effect in the respiratory zone of the lung due to saline infusion. On the other hand, in group C, hypoxemia might have occured not only because of decrease of VC but because of air flow obstruction due to remaining radiological opaque contrast medium in bronchial tree. It is necessary to monitor SaO_2 and/or supply oxygen during fiberoptic bronchoscopy, especially during BAL and BG procedure, to prevent hypoxemia.
