Repeated massive pulmonary air embolism during pacemaker implantation.

Pacemaker implantation is associated with the potential for various acute and late complications. Though they rarely occur, massive pulmonary air embolisms are lethal. We report the case of a 72-year old male with sick sinus syndrome who underwent permanent pacemaker implantation. Sedation was administered due to back pain with the resultant appearance of snoring. The procedure was complicated with repeated massive pulmonary air embolisms. The events occurred after the leads had been placed in the sheaths. The patient was successfully resuscitated with fluid challenge, O(2) supplement, vasopressor and catheter aspiration. This case illustrates that in a heavily sedated, snoring patient, the marked negative intrathoracic pressure can overcome the frictional resistance of air to being sucked into the gap between the lead body and sheath's wall. Careful manipulation alone is not enough to prevent pulmonary air embolisms. Aggressive treatment for upper airway obstruction is important. The use of a sheath with a haemostatic valve is strongly recommended if the upper airway obstruction cannot be treated adequately.