OMSK, September 8. /TASS/. Doctors in Omsk, where blogger Alexei Navalny spent nearly two days in hospital in a coma, did not use the special form of therapy called ultrahemodiafiltration, crucial to saving the life of a person poisoned with a Novichok class agent, the chief toxicologist of the Omsk Region and the Siberian Federal District, Alexander Sabayev, told the media on Tuesday, adding that there were no signs such treatment was required.

Ultrahemodiafiltration is used in case of a grave poisoning with organophosphorus compounds to which the Novichok class agents belong,

"Without ultrahemodiafiltration a poisoned person cannot be saved. We did not use this therapy, because there was no need for it. Had there been such a poisoning, he would have died within hours," Sabayev said.