Drug played role in Thai cave res­cue

The peo­ple re­spon­si­ble for the ex­trac­tion of the trapped soc­cer team re­vealed the evac­uees were drugged.

South Florida Sun-Sentinel (Sunday) - - Front Page - By Melissa Healy

The drug ke­tamine has en­joyed a long ca­reer as a work­horse anes­thetic. It had a brief run as a party drug known as “Spe­cial K.” And just last month, it won recog­ni­tion from the Food and Drug Ad­min­is­tra­tion as a fast-act­ing an­ti­dote for treat­ment-re­sis­tant de­pres­sion.

But In a new ac­count of the bold op­er­a­tion that freed 12 soc­cer play­ers and their coach from a wa­tery cave com­plex in Thai­land last July, ke­tamine is cred­ited with play­ing a key role in the res­cue.

In a let­ter pub­lished in The New Eng­land Jour­nal of Medicine, the med­i­cal pro­fes­sion­als re­spon­si­ble for mas­ter­mind­ing the safe ex­trac­tion of the trapped team re­vealed the evac­uees were anes­thetized with ke­tamine as they “were swum out of the cave wear­ing poorly fit­ting wet suits in cold wa­ter.”

In ad­di­tion to keep­ing the boys from pan­ick­ing dur­ing re­peated sub­mer­sion in murky, tur­bu­lent wa­ters, ke­tamine boasts a prop­erty rare among seda­tives: It causes blood ves­sels to con­strict rather than re­lax. That made it a good choice for the se­da­tion of pa­tients be­ing passed from res­cue worker to res­cue worker in cold wa­ters af­ter a long pe­riod of stress, de­hy­dra­tion and lack of food: They were less likely to de­velop hy­pother­mia.

Known as a “dis­so­cia­tive anes­thetic,” ke­tamine can pro­duce strange out-of-body sen­sa­tions and blunt fear and pain re­sponses. It can be ad­min­is­tered, even to a fran­tic pa­tient, with an in­tra­mus­cu­lar in­jec­tion — a prac­tice anes­the­si­ol­o­gists

re­fer to as a “ke­tamine dart.”

And un­like “twi­light drugs” such as propo­fol or di­azepines — seda­tives that ex­perts say were likely con­sid­ered and re­jected for this use — mod­er­ate doses of ke­tamine don’t sup­press breath­ing. That would have been a key con­sid­er­a­tion for pa­tients far from res­pi­ra­tory mon­i­tor­ing ma­chines or a me­chan­i­cal ven­ti­la­tor.

“You would get a co­op­er­a­tive boy who would keep breath­ing spon­ta­neously dur­ing the ex­trac­tion,” said Dr. John Ri­vard, an anes­the­si­ol­o­gist in Ann Arbor, Mich., who has par­tic­i­pated in med­i­cal mis­sions to Thai­land and 14 other coun­tries. “My hat is off to the team.”

Dr. Jeffrey L. Apfel­baum, a Univer­sity of Chicago anes­the­si­ol­o­gist, was also awed by the med­i­cal as­pects of the res­cue.

“The skillset 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.”

None of the 12 teens who played on the Wild Boars soc­cer team had any div­ing ex­pe­ri­ence, and sev­eral could not swim. But the boys, along with their coach, had been trapped for at least 15 days. If they didn’t run out of oxy­gen first, im­pend­ing mon­soon rains threat­ened to drown them.

To es­cape, one boy at a time would have to be squired through a treach­er­ous maze of pas­sage­ways filled with murky wa­ter of un­pre­dictable depth. A re­tired Thai navy SEAL had al­ready died while mak­ing the cross­ing, and the phys­i­cal and men­tal well-be­ing of the boys was ques­tion­able. The boys would need to breathe on their own, and pos­si­bly co­op­er­ate with in­struc­tions

as they were passed from res­cuer to res­cuer. And they could not panic, since each step of the re­lay was planned with mil­i­tary pre­ci­sion.

Writ­ing in The New Eng­land Jour­nal of Medicine, the emer­gency med­i­cal team that planned the boys’ es­cape re­vealed that res­cuers ad­min­is­tered “un­spec­i­fied doses” of “ke­tamine-based anes­the­sia” to each boy. Then they fit­ted their charges with a “full-face mask” that pushed oxy­gen-en­riched air into the lungs.

Upon their emer­gence from the Tham Luang cave com­plex July 8, the first four evac­uees had their full-face masks re­placed with oxy­gen masks that fit more loosely. They were also fit­ted with sunglasses to pro­tect eyes that had not been ex­posed to the sun in more than two weeks.

Each pa­tient’s head and neck were im­mo­bi­lized in

the event that some spinal trauma had oc­curred, then his wet suit was re­moved. Fi­nally, the pa­tients were bun­dled in blan­kets to ward off hy­pother­mia.

De­spite the pre­cau­tions, the sec­ond pa­tient to emerge from the cave com­plex de­vel­oped hy­pother­mia as he was be­ing trans­ported via he­li­copter from the field hos­pi­tal to Chi­an­grai Prachanukroh Hos­pi­tal.

While nor­mal body tem­per­a­ture hov­ers around 98.6 de­grees Fahren­heit, hy­pother­mia sets in when body tem­per­a­ture falls be­low 95 de­grees. At that tem­per­a­ture or be­low, the heart, ner­vous sys­tem and other or­gans be­come er­ratic. If a pa­tient’s core tem­per­a­ture is not raised — usu­ally with an in­fu­sion of warmed saline fluid and blan­kets — heart and res­pi­ra­tory fail­ure can lead to death.

The hy­pother­mic boy’s core tem­per­a­ture fell to 94.1 de­grees, a prob­lem at­trib­uted to “in­suf­fi­cient team co­or­di­na­tion,” ac­cord­ing to the med­i­cal jour­nal re­port. Af­ter that, an anes­the­si­ol­o­gist was as­signed to mea­sure evac­uees’ core tem­per­a­ture re­peat­edly once they emerged from the caves.

Dr. Richard Har­ris, an Aus­tralian anes­thetist who contributed to the re­port, has said he taught the divers per­form­ing the res­cue how to ad­min­is­ter ke­tamine to the boys, “and to read min­is­ter the seda­tive when the time was right.”

Af­ter a July cer­e­mony in which Har­ris was hon­ored for his role in the res­cues, he told re­porters that all of the chil­dren “needed re-se­da­tion at dif­fer­ent times on the way out.”

As a re­sult, anes­the­si­ol­o­gists sur­mised that the boys’ level of con­scious­ness likely var­ied in the course of their jour­neys out of the cave.

But while sev­eral Amer­i­can anes­the­si­ol­o­gists lauded the team’s de­ci­sion to use ke­tamine, some ac­knowl­edged that the seda­tive’s MacGyver-es­que use posed a few risks that were not, thank­fully, re­al­ized.

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.”

Apfel­baum said he be­lieves that many of the boys may have been deeply sedated for the most per­ilous stretches of the jour­ney. That would have ren­dered their bod­ies vir­tu­ally life­less, un­able to move or thrash about if they pan­icked, but still able to breathe and to be handed from res­cuer to res­cuer.

For some­where be­tween 5 per­cent and 30 per­cent of pa­tients — and for teens es­pe­cially — ke­tamine can in­duce fright­en­ing hal­lu­ci­na­tions, Gross said. And while res­pi­ra­tory sup­pres­sion is un­com­mon at mod­er­ate doses, “at higher doses, they may lose con­scious­ness and may stop breath­ing.”

LIL­LIAN SUWANRUMPHA/GETTY-AFP

The boys mark the end of a re­treat as novice monks Aug. 4, 2018, af­ter honor­ing a diver who died try­ing to save them.

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