CHIANG RAI: The 12 schoolboys and their football coach who were rescued from a cave in July last year were sedated with ketamine during the rescue operation, according to a report in CNN citing an article in the New England Journal of Medicine.
The "Wild Boars" football team and their coach got trapped on Jun 23 last year when they set out to explore the vast cave complex after a training session, when a rainy season downpour flooded the tunnels.
After more than two weeks, they were brought out over a three-day rescue operation involving about 90 divers from around the world.
Now, in a joint letter to the New England Journal of Medicine, three Thai medics and an Australian anesthetist said that the boys were given unspecified doses of ketamine while being rescued.
According to the World Health Organization, ketamine is safer to administer than other types of anaesthetic agents and pain relief as it does not depress breathing or lower blood pressure and does not require expensive patient-monitoring equipment.
"Its high level of safety makes it indispensable for surgery in low- and middle-income countries, disaster situations and conflict zones – where anaesthesiologists are scarce, and where running water, electricity and oxygen are unreliable," said WHO.
Ketamine was also a good choice for the perilous rescue, the medics said in their letter to the New England Journal of Medicine, as it impairs shivering and is associated with smaller drops in core body temperature - this would help to stave off hypothermia during the dive.
The boys also wore poorly fitting wetsuits and full-face masks that supplied them oxygen.
"We had to use the means that could keep the children not to be panicky while we were carrying them out," Thai Navy SEAL commander Arpakorn Yookongkaew told CNN after the rescue.
"Most importantly, they are alive and safe."
The joint letter also revealed details about the care the boys received after their rescue. Their heads and necks were immobilised to protect against spinal injury during the journey through the cave.
The first four boys who were rescued were given sunglasses to protect their eyes, as they were not exposed to the sun for more than two weeks.
'TIMING WAS CRUCIAL'
Dr Richard Harris, an Australian anesthetist, taught the divers how to administer the ketamine during different stages of the rescue, as timing was crucial.
"I had to basically teach the other cavers, the divers, to re-administer the sedation when the time was right," the Daily Mail reported Dr Harris as saying during a ceremony last July.
"All the children needed re-sedation at different times on the way out."
Dr Harris had to estimate how much sedative to administer the boys, as too little might have resulted in them panicking and drowning during the rescue, but too much would have caused them to lose consciousness.
"It was an estimate to start with. The first child was an experiment in a way," he said.
"It was a good guess with a lot of advice from a lot of other specialists. I was contacting specialists in Australia, I talked extensively with a variety of specialists in Thailand, and took a lot of their advice on board.
"And they were happy with the plan that we put forward - but I have never done it in the back of a cave with malnourished, skinny, dehydrated Thai kids before. That for me was the most frightening part of the week."