For the past two weeks, the whole world has been mesmerized by the plight of 12 boys and their soccer coach trapped inside a cave in Thailand.
On the other side of the world here in Texas, one doctor has done his part to help the rescue efforts.
Dr. Renie Guilliod, 56, medical director of hyperbaric medicine at the Institute for Exercise and Environmental Medicine in Dallas, became involved in an advisory role when he heard that a former Thai Navy SEAL team member had died Friday preparing for the rescue mission.
He sent an email to the governor of the province of Chiang Rai, Thailand, about the dangerous levels of carbon dioxide inside the cave.
"No one was mentioning the air quality, which was at 15 percent," Guilliod said. "Normally in properly ventilated conditions, human beings breathe in 20 to 21 percent oxygen, which is fine. But if it had dropped to 15 percent, then that meant that the carbon dioxide levels had to increase to at least 5 percent. These high levels of CO2 not only aggravate hypoxia because they affect the transport of oxygen to tissues, but they are also highly toxic."
From that point he was communicating with the Thai Navy SEALS through email, said Guilliod, also a faculty member at UT Southwestern Medical Center.
He proposed a set of solutions to stop the increase in carbon dioxide, how to breathe a lesser amount and how to reduce the levels inside the cave.
"Restricting the children's physical activity is crucial because the more they breathe, the more carbon dioxide level will increase," Guilliod said.
He also suggested moving the boys to a higher area inside the cave where they are now stationed to keep them breathing more oxygen and less carbon dioxide.
The estimated time to get a diver into the cave and out safely with each boy could take six or seven hours, but if the rains increase, it could possibly take about 11 hours, according to Guilliod. The monsoon flooding has blocked off any escape route and prevented rescuers from finding them for about 10 days.
"Since most of the boys can't swim, they will need their own oxygen tank and just a little bit of coaching," said Guilliod. "I continue to stress that we cannot underestimate the skill level of the cave divers. They are highly trained and skilled for this type of rescue. They could coach the boys in no time and get them to know the basics."
Should the rescue take longer than the next few days, he also offered the Thai Navy SEAL team suggestions to reduce the carbon dioxide levels.
They include injecting oxygen through a hose to increase the percentage of oxygen to a maximum of 24 percent, or placing plants and light inside the cave to increase oxygen levels through photosynthesis.
"This would be a permanent solution if they have to stay in the cave for several weeks," said Guilliod.
Fortunately, that might not be necessary. Eight of the boys have been rescued the past two days.
"I just helped to send a message about the quality of air inside the cave during the rescue efforts," said Guilliod. "The responsibility of completing the rescue was up to the Thai Navy SEALs and the experienced cave divers there. They did an amazing job."