Introduction
Venous gas embolism is a rare but potentially catastrophic complication in laparoscopic surgery.1-4 Sudden cardiovascular collapse and neurologic deficit can be seen after the embolism. Signs and symptoms include profound hypotension, tachycardia, dysrhythmias, asystole, hypoxemia, cyanosis and pulmonary edema.1,2 The incidence of clinically significant CO2 embolism varies from 0.001% to 0.59%, and mortality can be as high as 28.5%.2,3 We present a case of a patient with possible venous gas embolism during laparoscopic surgery.
Case description
A 37 year old female presented to gynecologic oncology clinic with a newly diagnosed presacral mass consistent with low-grade serous ovarian carcinoma. She was scheduled for diagnostic laparoscopy, exploratory laparotomy and tumor reductive surgery. She was taken to the operating room for her procedure. The patient was premedicated with midazolam and at induction she was given propofol, ketamine, fentanyl and lidocaine. Rocuronium was also used to facilitate orotracheal intubation. Maintenance of anesthesia was achieved with propofol, dexmedetomidine and lidocaine infusion. For diagnostic laparoscopy, pneumoperitoneum was obtained with 15mmHg CO2, and the patient was placed in reverse trendelenburg. Subsequently, her MAP dropped to mid-50s, O2 saturation to 30%, Vt to 127ml and EtCO2 to 15mmHg; her PIP raised to 56cmH2O. Pneumoperitoneum was released and the patient repositioned. Endotracheal tube placement was confirmed. Use of phenylephrine and ephedrine was also necessary. Anesthesia team performed a TEE in the OR was patient was stabilized, no evidence of embolus was seen. The episode lasted about 5 minutes. Surgery was canceled, and the patient transferred in stable conditions to the ICU. A CT of the chest was obtained later and it showed no evidence of embolus.
Discussion
Venous gas embolism, although rare, can be lethal. Multiple procedures in different specialties can be complicated by gas embolism, including laparoscopic, neuro, orthopedic and gynecologic surgery. It occurs when gas enters the venous system; usually as series of gas bubbles which are subsequently transported to the right ventricle. Migration of air to the pulmonary circulation increase pulmonary arterial pressure and resistance to right ventricular outflow, leading to diminished pulmonary venous return, left ventricular preload and cardiac output, thus, resulting in systemic cardiovascular collapse.5 Diagnosis can be done through clinical findings, EtCO2, precordial doppler ultrasonography, exclusion of other embolic etiologies, and ultimately TEE.3,5 Management includes prevention of further gas entry, cardiopulmonary resuscitation, volume expansion, oxygen administration, use of vasopressors if needed, repositioning of the patient, aspiration with CVC and hyperbaric oxygen.5

Venous gas embolism (VGE) in a patient with ovarian cancer during laparoscopic surgery