Massive pulmonary air embolism during the implantation of pacemaker, case reports and literature analysis.

OBJECTIVES: Pacemaker implantation has developed into a mature technology, meanwhile, implantable cardioverter-defibrillators (ICD) and cardiac resynchronization therapy (CRT), as extended pace making technology, are both carried out in rising frequency. Massive pulmonary air embolism is a rare but fatal complication accompanying with such pace making process. The objective of this study was to investigate the epidemiology, pathophysiological mechanism, occurrence and treatment for this kind of complication. PATIENTS AND METHODS: Two cases of complicated massive pulmonary gas embolism were presented: one in CRT and the other in pacemaker implantation, both of which were captured rapidly and treated successfully by inhalation of high flow oxygen, closure of gas inflow tract, position change, and vasoactive drugs. Moreover, published literatures about air embolism in the process of pacemaker implantation or CRT/ICD were summarized and analyzed. RESULTS: Complicated massive pulmonary air embolisms could be successfully resolved with satisfied short-term prognosis. Literature analysis showed that massive pulmonary air embolism is very rare in the course of pacemaker implantation, and coughing or deep breathing, advanced age, preoperative sedation, sheath with large cavity, improperly operating the hemostasis valve and diminished compliance of pulmonary circulation might be risk factors for air embolism. CONCLUSIONS: Massive pulmonary air embolism during pace making which is very rare in the course of pacemaker implantation is one kind of life-threatening complication. Rapid judgment and timely treatment can avoid a catastrophic event, which could prevent adverse impact on the short-term prognosis, while further observation is required to explore the long-term prognosis.