Systemic Air Embolism during ERCP with Full Recovery

Air embolism during gastrointestinal endoscopy procedures is a rare phenomenon but can lead to a catastrophic and fatal event resulting from cardiovascular collapse and neurological injury. Oftentimes, the diagnosis is difficult because the cardiovascular and neurologic symptoms are not specific to systemic air embolism. High index of suspicion with early recognition and treatment is crucial in improving patient outcome. We present a case of cardiac arrest secondary to systemic air embolism during endoscopic retrograde cholangiopancreatography with biliary stent placement which resulted in a good outcome due to early recognition of air embolism and prompt treatment. Case Report A 57-year-old male with history of seizures, hypertension, alcohol abuse and stroke with residual right sided weakness, presented with abdominal pain. Hepatobiliary iminodiacetic acid scan (HIDA) scan showed non-visualization of the gallbladder concerning for cystic duct obstruction. The patient was taken to operating room for laparoscopic cholecystectomy which was converted to an open cholecystectomy, due to a common hepatic duct (CHD) injury. This was repaired over a T-tube. Postoperatively, patient was found to have a bile leak from the CHD injury. On post-operative day 5, the patient underwent an uneventful ERCP procedure with sphincterotomy and common bile duct stent placement. The patient, however, continued to have persistent large volume bilious output from his Jackson-Pratt (JP) drain and a subsequent CT scan revealed a large biloma. A week later, the patient was taken to the GI suite for a second ERCP due to concern for persistent bile leak. The patient was afebrile, with a baseline systolic blood pressure 130-145, heart rate 60-70, and oxygen saturations of 98-100% on room air. The patient was 172 cm in height, and 62 kg in weight. General anesthesia was planned for airway protection. The patient was preoxygenated and premedicated with 2 mg midazolam and 100 mcg fentanyl. Standard ASA monitors were recorded intraoperatively. The patient was then induced with 1 mg/kg of protocol and with 0.7 mg/kg rocuronium for muscle relaxation via a 20 G peripheral IV. Intubation was atraumatic with a MAC 3 blade and a cuffed endotracheal tube #8. End-tidal carbon dioxide (EtCO2) was kept between 29-39 mmHg with mechanical ventilation on volume control mode. Vital signs were stable after induction and intubation. Anesthesia was maintained with 0.3-0.5 MAC of Sevoflurane on 100% FiO2. Patient was turned prone for the procedure. Thirty minutes into the procedure, a precipitous drop in EtCO2 (29 to 17 mmHg), measured via capnography, was noted with concomitant hypertension (BP ~ 170/110 mmHg) and narrow complex tachycardia (HR ~ 120). Within one minute, EtCO2 dropped to 1-2 mmHg associated with severe hypoxia (Sp02 ~ 40%) and central cyanosis, most evident at the neck and face. The carotid pulse was not palpable at this time. Since air has been traditionally used in our GI suite for insufflation, venous air embolism was quickly suspected. The GI endoscopist was immediately notified to abort the procedure. A gurney was brought into the room and the patient was turned supine and positioned with head down position (Trendelenburg). Advanced cardiac life support (ACLS)was initiated as the patient demonstrated pulseless ventricular tachycardia. After 10 minutes of ACLS, with defibrillation × 1 at 200J, 3 mg of epinephrine, and bicarbonate 50 mEq × 4, return of spontaneous circulation was Introduction Endoscopic retrograde cholangiopancreatography (ERCP) is a commonly performed procedure used for both therapeutic and diagnostic purposes which include: assessment of the pancreatobiliary system, endoscopic sphincterotomy for treatment of choledocholithiasis, and placement of biliary duct stents. Visualization of the pancreatobiliary system is achieved with retrograde injection of contrast media through the ampulla of Vater followed by therapeutic intervention. In the United States, approximately 500,000 ERCPs are performed annually with a complication rate between 4% and 10%, and mortality between 0.05% and 1% [1,2]. The most common complications include pancreatitis (3.5%), infection (1.4%), gastrointestinal bleeding (1.3%), and perforation (0.6%). Air embolism following ERCP is rare, with a total of 26 documented cases reported [3]. ERCP involves insufflation of gas into the bowel lumen in order to provide operating space and improve visualization [4]. Air and carbon dioxide are the two most commonly used insufflation agents. Air is not absorbed by bowel and instead is passed via flatus. This can lead to gas retention and contributes to post-ERCP discomfort [4]. In contrast, carbon dioxide (CO2) is easily absorbed into the bloodstream and eliminated via the respiratory system, reducing the risk of embolism [5]. Elevated systemic CO2 in the bloodstream has been associated with physiologic perturbations, including tachycardia and cardiac arrhythmias [4]. Of all the gastrointestinal endoscopic procedures, ERCP has the highest risk of air embolism [6]. Dellon, et al. reported that there were no patients with gas embolism related to CO2 insufflation [5]. We report a case of air embolism during ERCP with full recovery from prompt recognition and adequate resuscitation.