Selective tracheobronchial aspiration.

Eighty attempts at placing suction catheters in the left main bronchus were analysed by studying chest radiographs. When angled catheters were used via a tracheostomy tube the success rate was 75%; the rate fell to 15% when straight tubes were used through an orotracheal tube. Assessment and control of the tube length was found to be important to avoid kinking and subsequent obstruction of the catheters.