UPSC-CMS 2014 — Surgery

Q: Which one of the following is the safest gas for creating pneumoperitoneum in operative laparoscopy?

Carbon dioxide. ***Carbon dioxide*** - **Carbon dioxide (CO2)** is the gold standard for creating **pneumoperitoneum** because it is rapidly absorbed from the **peritoneal cavity** and excreted by the lungs, minimizing the risk of gas embolism. - Its **high solubility in blood** (20x more soluble than nitrogen) reduces the risk of serious complications if inadvertently injected intravascularly. - **Non-combustible** and does not support combustion, making it safe to use with electrocautery and other heat sources during surgery. *Oxygen* - **Oxygen** is highly **combustible** and would create a significant fire hazard in the presence of electrocautery or other heat sources during surgery. - It could also cause **gas emboli** if it enters the bloodstream, as it is less soluble than CO2. - Risk of **oxidative tissue damage** with prolonged exposure. *Carbon monoxide* - **Carbon monoxide** is extremely **toxic** and binds irreversibly to hemoglobin with 200-250 times greater affinity than oxygen, forming **carboxyhemoglobin**, which impairs oxygen transport. - Even minimal exposure can be life-threatening due to systemic hypoxia. - Absolutely contraindicated for clinical use. *Nitrous oxide* - **Nitrous oxide** can diffuse into gas-filled spaces (bowel loops) 30x faster than nitrogen, potentially causing **bowel distension** and increased intra-abdominal pressure during prolonged procedures. - Although less of a fire risk than oxygen, it can **support combustion** at high concentrations. - Less rapidly absorbed than CO2, posing higher embolism risk if intravascular injection occurs.

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Q21

Which one of the following is the safest gas for creating pneumoperitoneum in operative laparoscopy?