Hiatal Hernia

I recently had a hiatal hernia repaired with laparoscopic surgery, during which the surgeon used CO2 to inflate my abdominal cavity. One of the side effects is shoulder pain on my left side, which my doctor said was due to the CO2 permeating the tissue. Pain medicine has not been working, so my doctor suggested walking to get rid of the excess gas. Since this seems similar to decompression sickness (DCS), should I be concerned about future dive trips?

During laparoscopic surgery, surgeons insert tubes with lighted cameras and surgical instruments to repair the hernia with minimal intervention. To expand their view, surgeons often use gas to create a space called a pneumoperitoneum. CO2 is the preferred gas in laparoscopic surgery due to its high solubility in the blood and its resistance to combustion, which is particularly important with the presence of electrosurgical equipment. Another benefit is that you can rapidly clear CO2 from your body as a natural byproduct of respiration.

Shoulder pain is a common side effect of a pneumoperitoneum. The phrenic nerve originates from the same level of the cervical spine (neck) as the nerves that provide sensation to the shoulders and descends downward between the lungs to the diaphragm. The diaphragm and shoulder thus share the same nerve path. Trapped CO2 can irritate the phrenic nerve and cause shoulder pain, and movement may help release the gas. Residual effects of a pneumoperitoneum and CO2 retention resolve within seven days in 96 percent of the patients who undergo this procedure.  

The pathophysiology of referred pain from laparoscopic procedures is quite different from the way DCS may cause shoulder pain while scuba diving. Many factors can lead to DCS, including overall fitness to dive, general health, hydration status and thermal status. While you may or may not be at a greater risk for DCS after surgery, it is prudent to refrain from diving until you have completely healed and your surgeon has released you for unrestricted, rigorous activity.

Remember that there is always some degree of DCS risk any time you dive, so take measures to minimize that risk. Continuously monitor yourself for signs and symptoms of DCS following a dive, and seek medical attention at the nearest appropriate facility if symptoms develop.  
— Robert Soncini, NR-P, DMT