The conditions of the rescue of the 12 soccer teens and their coach from the Tham Luang cave complex back in July were incredibly harrowing, and everyone involved faced the imminent risk of death throughout the ordeal. The players themselves were undoubtedly terrified, but according to a new letter posted to the New England Journal of Medicine, their anxiety was blunted by strategically timed doses of ketamine, an extremely powerful sedative.
The report is titled “Prehospital Care of the 13 Hypothermic, Anesthetized Patients in the Thailand Cave Rescue,” and you’ll need a subscription to read it, and anyway most of what it’s concerned with is how players were rewarmed upon rescue in order to safeguard against hypothermia. Thankfully, the Los Angeles Times has a summary of it, along with some reporting of their own on how ketamine would’ve affected the players and their coach throughout the dangerous rescue operation. The upshot is, depending upon the level of each dose and how regularly doses were administered, the players would’ve been somewhere between deeply relaxed and catatonic. From the Times report:
Dr. Jeffrey B. Gross, chairman of the University of Connecticut’s department of anesthesiology, said that light sedation with ketamine will “basically scramble your brain a bit but won’t put it to sleep.” At some points, the boys may have been able to follow simple directions. But their ability to perform complex maneuvers, such as swimming, would be doubtful, he said.
At a larger dose, Gross added, “they’d give you a blank stare. The lights are on but nobody’s home.”
The decision to sedate the players and their coach apparently would’ve presented its own risks, especially given the circumstances. Ketamine can induce “frightening hallucinations,” especially in teens, and though it would’ve prevented panic, it also would’ve prevented the players from signaling if they were experiencing any sort of distress—like, say, if their “poorly fitting” wet suits had failed. And at the dosage level that would’ve induced the calmest, most pliable, most zombie-like state, patients reportedly “may lose consciousness and may stop breathing.”
Rescuers were obviously aware of these risks, and their decision to proceed with sedation underscores just how much immediate danger the players faced during the 2.5-mile journey to the mouth of the cave complex. They’d been stranded underground for more than two weeks, were malnourished and exhausted and frightened, and none of them had any diving experience. Three of them could not swim. Prior to their rescue, an expert diver and former Navy SEAL had died making the passage. In order to get from the their pitch-black sanctuary deep in the cave complex all the way to daylight, they’d need to be passed from rescue diver to rescue diver through “a treacherous maze of passageways filled with murky water of unpredictable depth,” in a sequence mapped out “with military precision.” Panic and confusion would pose an immediate threat to everyone involved, and would’ve been an absolute certainty among kids who were both physically weak and not real great swimmers to begin with. From the Times report:
“The skill set necessary to get these kids out is just unbelievable,” Apfelbaum said. “There are countless ways, both medical and from a diving perspective, where tragedy could have occurred. By no means was any of this straightforward.”
Ketamine is serious business, but there are some fascinating reasons why it’s more suitable for this kind of emergency situation than less severe sedatives. According to the NEJM letter, ketamine “impairs shivering,” and “is associated with smaller drops in core temperature,” which makes it the sedative of choice in situations where hypothermia is a risk. The Times says this quality is due to a unique property of ketamine among sedatives: it constricts rather than relaxes blood vessels, and vasoconstriction slows the flow of blood and helps retain body heat. Ketamine also reportedly doesn’t suppress breathing at moderate doses, although exactly how much was administered is left out of both the letter and the report.
All 12 players and their coach were successfully rescued from the cave complex, with the last boy being safely extracted after a whopping 18 days underground. The NEJM letter is short and bone dry, but I highly recommend the Los Angeles Times report. Go read it.