BBC

“…..Dr Stephen Jukes, an intensive care consultant at the hospital, said: “When we first were aware this was a nerve agent, we were expecting them not to survive.

“We would try all our therapies. We would ensure the best clinical care. But all the evidence was there that they would not survive.”

Both Skripals were heavily sedated which allowed them to tolerate the intrusive medical equipment they were connected to, but also helped to protect them from brain damage, a possible consequence of nerve agent poisoning.

Over time, the sedation was reduced and the ventilation switched from the mouth to the trachea, as shown by the vivid scar seen on Yulia Skripal’s neck in the TV statement she gave after she was released.

Once the patients became more conscious, staff had to carefully consider what they could tell them without prejudicing the police investigation, and decide on the right moment to allow questioning by detectives.

Medical director Dr Christine Blanshard explained: “Those are very difficult decisions, because on the one hand you want to provide reassurance to the patients that they are safe and they are being looked after, and on the other hand you don’t want to give them information that might cause difficulties with subsequent police interviews.”

It was the doctors and nurses that, out of concern for their patients, insisted that international inspectors obtain a court order before they would be allowed to take blood samples from the Skripals.

Dr Jukes explained: “These are vulnerable patients, they needed some form of advocate and without a court order we could not allow things to happen to them without their consent.”

Once the Skripals were stable and able to speak, the key concern for medical staff was how their production of the key enzyme acetylcholinesterase – needed to re-establish their normal body functions – could be stimulated.

The body will do this naturally after nerve agent poisoning, but the process can take many months.

In trying combinations of drugs, Dr Murray says the hospital received input from “international experts”, some of them from Porton Down.

The laboratory, internationally known for its chemical weapons expertise, processed tests and offered advice on the best therapies.

New approaches to well-known treatments were tried. Dr Jukes said that the speed of the Skripals’ recovery came as a very pleasant surprise that he cannot entirely explain……”