New Scientist - USA (2019-11-30)

30 November 2019 | New Scientist | 9

Tisherman. “We’re trying to buy
ourselves more time to save lives.”
How much longer someone can
be in suspended animation isn’t
clear. When a person’s cells are
warmed up, they can experience
reperfusion injuries, in which a
series of chemical reactions
damage the cell – and the longer
cells are without oxygen, the more
damage occurs.

First steps

It may be possible to give people a
cocktail of drugs to help minimise
these injuries and extend the time
for which they are suspended,
says Tisherman, “but we haven’t
identified all the causes of
reperfusion injuries yet”.
Tisherman described the team’s
progress last week at a symposium
at the New York Academy of
Sciences. Ariane Lewis, director of
the division of neuro-critical care
at NYU Langone Health, said she
thought it was important work,
but that it was just first steps. “We
have to see whether it works and
then we can start to think about
how and where we can use it.”
Although Tisherman’s team
has been working on the trial
since 2014, it may take a while to
complete. In order for a patient to
be enrolled, they must be present
in the hospital at the same time
as the large team trained in the
technique. “The team’s probably
a little too big,” says Tisherman.
“But when you’re doing
something like this, everyone
wants to be a part of it.”
Tisherman says he hopes to be
able to announce the full results
of the trial by the end of 2020. ❚

Isn’t suspended animation

a bit like an induced coma?

Yes, there are similarities

between the two. A medically

induced coma uses drugs to

slow the metabolism of the

brain (so it needs less oxygen)

to help reduce swelling and

aid its recovery.

However, suspended

animation goes a lot further

by lowering people’s body

temperature to almost

completely stop metabolism

in the body and brain.

Haven’t we been cooling the

body to lower metabolism

for years?

Yes, we have. Cardiac surgeons

will often lower a patient’s body

temperature slightly while

performing operations on

the heart. But suspended

animation lowers body

temperature much further –

to around 10 to 15°C – at which

point most metabolic reactions

slow or stop completely.

Do people get to choose whether

they are put into suspended

animation?

The technique is only used as

a last resort, meaning the team

at the University of Maryland

School of Medicine, led by

Samuel Tisherman, will have

done everything they can to

save the person’s life the

regular way first. People who

experience a cardiac arrest from

traumatic haemorrhage are

unlikely to survive with current

treatments.

In order to get approval for

the trial, the researchers had

to have several consultations

with the public. They also put

details of the trial in the local

newspapers, and made a website

where people can opt out.

Is a patient’s future health

considered before this

procedure?

The researchers can’t give an

accurate prognosis until this

trial has been completed. If it

shows promise, they are likely

to extend the trial to include

more people.

What they do know is

that people who experience

a cardiac arrest in these

circumstances are unlikely

to survive with available

treatments. This is essentially

a last ditch attempt at saving

their life.

Tisherman said last week

that if the researchers

absolutely knew they couldn’t

fix the patient’s injuries, they

wouldn’t be considered. The

patient’s quality of life, among

other ethical aspects, was

considered before the trial

was approved.

Would this procedure only be

available to the rich or famous?

No, it doesn’t distinguish

between rich and poor. There

are several conditions for being

a participant, not least that you

need to have had a cardiac

arrest due to trauma and have

been brought to the correct

hospital. The technique

involves a lot of doctors who

all have to be present at the

right time.

What’s the real potential

of the technique?

The dream scenario is that you

would be able to keep people in

this state for months or years

while they await a cure for their

condition. But this is a distant

dream – this trial is the first step

and we don’t know yet whether

the technique is effective.

So is immortality the endgame

of all this?

The endgame is about saving

the life of someone who would

almost certainly have died. You

might liken it to the invention

of the defibrillator – before that,

many people who had a cardiac

arrest would have died. Now

some of them live as a result

of that technology. ❚

Q&A

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It only takes 5 minutes

without oxygen before

brain damage occurs

“ The dream scenario is

that people spend years

in this state while they

wait for a cure”

Helen Thomson is

a consultant for New

Scientist and tweets

as @hvthomson

Your questions answered New Scientist readers put their

questions about the emergency resuscitation and preservation

procedure to Helen Thomson