A lady presented in the emergency depament with a stab injury to the left side of the abdomen. She was hemodynamically stable and a contrast enhanced CT scan revealed a laceration in spleen. Laparoscopy was planned however the patient&;s pO2 suddenly dropped as soon as the pneumoperitoneum was created. What is the most likely cause

The hallmark of pulmonary embolus s a marked drop in the PO2. In this case it occurs the splenic vessels. Gas emboli are rare but serious complications of laparoscopic surgery. They should be suspected if hypotension develops during insufflation. Diagnosis may be made by listening (with an esophageal stethoscope) for the characteristic "mill wheel" murmur. The treatment of gas embolism is to place the patient in a left lateral decubitus position with the head down to trap the gas in the apex of the right ventricle. A rapidly placed central venous catheter then can be used to aspirate the gas out of the right ventricle. Reference: Schwaz Principles of Surgery, 10th edition, Page no 418.