Question

A lady presented to the emergency department with a stab injury to the left side of the abdomen. She was haemodynamically stable and a contrast-enhanced CT scan revealed a laceration in the spleen. Laparoscopy was planned, but the patient's pO2 suddenly dropped as soon as the pneumoperitoneum was created. What is the most likely cause?

• A. Gas embolism through splenic vessels
• B. Injury to the left lobe of the diaphragm
• C. Inferior vena cava compression
• D. Injury to the colon

Hint:

Open vein plus pressurised CO2 the moment you insufflate equals gas in the circulation.

Answer 1

The Correct Option is A

Step 1: The key event is an abrupt fall in pO2 at the exact moment carbon dioxide pneumoperitoneum is created, in a patient who has an open laceration of a vascular organ, the spleen.
Step 2: Pneumoperitoneum is made by insufflating CO2 into the abdomen under positive pressure. The lacerated splenic vessels provide an open, low-pressure venous channel directly exposed to that pressurised gas.
Step 3: The high intra-abdominal CO2 pressure can be forced into the opened splenic veins, producing a gas (CO2) embolism. The gas travels to the right heart and pulmonary circulation, blocking gas exchange and causing a sudden drop in pO2 and oxygen saturation.
Step 4: A diaphragmatic injury (option B) can cause respiratory compromise but would not classically produce an instantaneous desaturation precisely synchronised with insufflation. IVC compression (option C) lowers venous return and blood pressure rather than causing an acute hypoxic drop. Colonic injury (option D) does not cause acute hypoxia.
Step 5: The temporal link between creating pneumoperitoneum and the sudden hypoxia in a patient with open splenic vessels points to CO2 gas embolism.
Answer: A. Gas embolism through splenic vessels.