NEW SCIENTIST NEWSFLASH
Russian gas clues point to cocktail
Further evidence about the Moscow knock-out agent suggests a mixture of anaesthetic and opioids
Further clues to the identity of the knock-out agent used to end the Moscow hostage crisis have emerged, indicating that a likely candidate is a cocktail of an opioid narcotic such as fentanyl supplemented by halothane, a common anaesthetic. The two are commonly used together in clinical anaesthesia.
The Russian authorities are maintaining their silence on the identity of the gas, which they used to incapacitate the Chechen hostage-takers on Saturday. But the gas is believed to have killed all but two of the 117 hostages who died. The first funerals have already been held.
Late on Tuesday, doctors in Munich reported that chemical analysis had identified halothane in blood and urine samples taken from two surviving German hostages within 24 hours of the rescue.
But David Whittaker of the Association of Anaesthetists of Great Britain cautions that the two may have received halothane as an emergency treatment for bronchospasm induced by inhaling vomit, which happened to many hostages. If this true, it is probable that an opioid was used alone.
Peter Hutton, president of Britain's Royal College of Anaesthetists, adds: “Halothane would take several minutes to get people even partially asleep." The gas used in Moscow rendered hostage-takers unconscious much more quickly, preventing them from donning gas masks or detonating their explosives.
However halothane in the agent would at least agree with what little Russian officials have said – “it was a medical gas used in anaesthesiology”.
Opiate intoxication
Doctors at the US embassy in Moscow say the two American survivors they examined had the telltale signs of opiate intoxication. Moreover, Moscow doctors have reportedly been treating survivors successfully with naloxone, which blocks the action of opiate drugs. And breathing failure and inhalation of vomit, said to be the most common cause of death in the hostages, are caused by opiates.
“There is already an inhalable opiate available – fentanyl, a short-acting, rather potent narcotic,” says Alan Zelicoff, a chemical and biological warfare expert at Sandia National Laboratory in New Mexico, US. “The clinical utility of this drug is that it acts very quickly.”
Fentanyl is commonly combined with halothane in order to minimise halothane’s toxic side effects. And halothane may have been used to extend the effect of the agent, as the fentanyl wore off. But at high doses fentanyl alone may have been sufficiently long lasting. Both compounds must be administered as an aerosol suspension – tallying with the “grey” mist reported by some hostages.
Lethal dose
The most likely cause of the terrible number of hostage deaths is the side effects of fentanyl, say observers. Martin Furmanski, a medical historian in Newport Beach, California, says administering enough of an opiate drug to cause rapid anaesthesia almost always causes a patient to stop breathing – not a problem in a fully-equipped operating theatre, but a tragedy in the Moscow theatre.
Similar opioids are used in tranquilising darts for anaesthetising large animals. In these cases, the lethal dose is just six times greater than the dose needed for anaesthesia.
That implies that if the Moscow hostage-takers were exposed to enough of the mixture to knock them out within one minute, hostages who kept breathing it would have acquired a lethal dose within six minutes.
If this analysis is correct, notes Furmanski, the poor physical condition of the hostages, or a dosage miscalculation is not necessary to explain the mass deaths. “It was probably inevitable that many hostages would die if the aerosol opiate concentration was high enough to cause rapid unconsciousness in the terrorists,” he says.
Short of Russian officials naming the agent, the next information is likely to come from the examination of the remains of two US hostages who died, and clothing from a British family, now being examined at the UK’s chemical defense lab at Porton Down. However, rapid breakdown of short-acting opioids such as fentanyl might mean analysts will have to look for longer-lived breakdown products of the drug.
copyright 2002 Reed Elsevier
Sharpshooters? Most likely you'd have to take out every terrorist at once. There was no other way. The Russians knew it, the media probably knows it, and, deep down, you know it, too. I agree with what happened. I feel sorry for the innocents who died, but I don't think giving the terrorists what they wanted would've been a better plan, do you?
well done!