Whilst using a mechanical gas blender the first gas on cardiopulmonary bypass showed a very low pCO2. Reducing gas flow rates made no difference. Swapping out the blender resolved the problem. On inspection the fine trim rotameter knob was found to be fully open delivering a gas flow in excess of 30L/min. When fully open the small ball float is difficult to visualise.
The Safety Committee recommends that a check is made on the gas blender to ensure that the rotameter knobs are correctly set prior to establishing CPB. Consider incorporating into departmental checklists if not already included.
