Abstract: Objective To place the central venous catheters accurately guided by the intracardic electrocardiography(ECG) and investigate the effects of aspirating air embolus in sitting position neurosurgical operation.Methods Thirteen sitting operation patients who received a central venous catheter to aspirate air embolus were enrolled.The central venous catheter was accurately placed by using guiding wire as internal electrode to record intracardiac signals.The position of the catheter was assessed through the changes in intracardiac ECG and re-checked with X-rays after operation.When air embolus was detected,it was aspirated through the central venous catheter and the volume of air calculated.Results The technique of using intracardiac ECG to guide the placement of central venous catheter was accurate.Seven air emboli were detected in 13 patients.The success rate of aspiration was 100% and the volumes of aspirated air were from 0.5～20 mL.Conclusion The technique of using intracardiac ECG guidance to detect central venous catheter tip is convenient and accurate;Air embolus can be aspirated effectively.

Key words: central venous catheter, endocavitary electrocardiography, sitting operation, air embolus