BREATH OF FREEDOM:
UTILITY OF CHEMICAL AGENTS IN ANTI TERRORIST OPS
On Wednesday the 23rd of October 2002 about 50 armed Islamist Chechen terrorists forced their way into a Moscow theater which was showing a musical and took about 800 people hostage. The terrorists threatened to blow themselves and the theater up, and kill all the hostages.(1,4)
The standoff, and the hostages ordeal, continued for 3 days and as the world watched through the eyes of the media parked outside the theater, hopes for a settlement without massive bloodshed were fading. But Russia sprang a surprise on the terrorists and the watching world. In a 'first time ever' action, seemingly taken straight out of science fiction books, Russian security forces used a mystery "knockout gas" to incapacitate the terrorists and hostages alike, stormed the theater and killed all the terrorists and rescued over 750 hostages (2,3). The rescue came at a high cost - with 117 (4) to 119 (5) hostages having died without injury from causes that have been allegedly attributed to the use of a chemical agent to overpower the terrorists and their hostages.
The purpose of this paper is to examine the role of chemical agents in reversibly and safely overpowering groups of people in closed areas. Some technical aspects regarding the use of these agents will be discussed, along with the particular difficulties and dangers and a description of known chemical agents that could be used in such situations. Chemical agents designed to cause death will not be discussed. The two agents currently thought to have been employed by the Russians in this hostage crisis, Fentanyl(4,6) and possibly Halothane(5,6) are described.
TECHNICAL CONSIDERATIONS:
The ideal "knockout gas" for use in hostage situations should have the following
characteristics:
* Solubility and Uptake:
It should be capable of passing into the blood from the air in the lungs and then pass
from the blood into the brain
* Physical Properties:
It should be colorless and odorless.
* Volatility:
The agent should be easy to disperse in large volumes quickly.
* Potency:
It should be capable of acting rapidly to cause unconsciousness when breathed in -
perhaps acting over the span of 10 or 12 breaths.
* Pharmacological Effects:
It should then be very safe so that even if an unconscious person continues to breathe
the gas for several minutes or hours it should not cause any further damage or
complications.
* And lastly, the effect of the gas should be rapidly reversible. That is, either the gas
should be spontaneously washed out by the body when exposure is terminated, or its
effect should be easily reversed by an antidote.
Unfortunately no such ideal gas or compound exists.
The most commonly employed agents that rapidly cause unconsciousness are used routinely for general anesthesia for surgical operations. But every single one of these agents has drawbacks that make it less than ideal for use as a gas to render people unconscious, safely and securely, without intensive (close) medical supervision.
Some chemical agents may not be reliably absorbed from the lungs when breathed, and are best given as injections or tablets. Others may act very slowly, even if absorbed from the lungs. These are obviously unsuitable, and can be ruled out.
Many agents have a characteristic odor that makes them easily detectable. Some are irritant and may cause coughing or burning of the eyes. Either way, the use of such agents could trigger a dangerous panic reaction from a tense, tired hostage taker before they cause unconsciousness.
Some agents occur as powders or liquids, and these will need to be dispered in the air for them to be inhaled. This may not be a very difficult technical hurdle to cross. Many countries, and Russia in particular have developed great expertise in creating aerosols from liquids or powders. Aerosols(7,8) are minute droplets or powders suspended in a gas. Aerosols can be generated from powders or liquids by accurate control of particle size, shape, concentration and electric charge(9) The Federal Institute of Applied Chemistry in Russia (10) has developed great expertise in this area.
If all the above conditions are adequately met, there still remains the crucial question of safety. Contrary to popular belief chemical agents that cause sedation, narcosis or loss of consciousness do not cause "sleep" in the true sense of the word. A person who is asleep is rousable and is able to regain full consciousness rapidly. But a person who is under the influence of a drug that causes unconsciousness is in a state akin to a drunken stupor.
All the agents used suppress brain functions to cause this stupor, and whenever brain function is suppressed the part of the brain that controls breathing is also suppressed to an extent. The higher the dose of the "knockout agent" the greater the suppression of breathing, (and other side effects) leading eventually to a cascade of events in the body that can cause death. Unlike injections or tablets that provide a fixed dose of chemical agent to the body, an agent that is present in the atmosphere will be inhaled with each breath and the dose of the substance reaching the blood and brain will increase with each breath and eventually lead to possible fatal overdosage unless the chemical laden air that is being breathed can be quickly replaced and substituted with normal air or oxygen. A number of individual factors may delay or accelerate death under such circumstances. Younger people with healthy cardiac and respiratory systems will last longer as may people who are drug addicts or alcoholics, whose bodies may destroy some agents faster than normal. Elderly people with heart disease, and people weakened by disease or starvation and dehydration will likely succumb faster.
This then sets the stage for the effects of introducing an anesthetic or sedative gas into a confined sapce, such as was done in Russia. Within the space, people sitting near vents through which the gas is introduced will receive higher doses more quickly than those sitting away from vents, and in these areas, the elderly and weak will succumb soonest from an overdose, possible even before others in other areas lose consciousness. This theoretical model fits in well with the reports of the Moscow siege, with a mixed picture of people who were conscious and unconscious, some deaths, while some people remained relatively unaffected.
AGENTS WHICH SATISFY SOME OR MOST OF THE REQUIREMENTS DESCRIBED ABOVE ARE AS FOLLOWS:
Nitrous Oxide, Halothane, Enflurane, Isoflurane, Sevoflurane, Desflurane
Other volatile agents which do cause loss of consciousness, but unfit for a mission such as the Moscow theater crisis are:
Vallium, Chloroform, Cyclopropane, Methoxyflurane, Trichloroethylene, Fluroxene, Diethylether.
There are a number of agents which are under research and might qualify as Anaesthetic agents of the future are:
Xenon, Compound 485, Thiomethoxyflurane, n-Pentane, Diosychlorane.
In addition, Argon, Nitrogen, and Hydrogen also induce Anaesthetic effects, but they are rarely used.
We will also consider Opiate derived drugs and reasons why it was chosen over others in the operation to neutralise the Chechen Terrorists inside the Moscow Theater.
We will consider the most likely agents and their pros and cons and thus, the suitability of their usage in a Hostage situation.
Note: The potency of an anaesthetic gas can be defined by the concentration required to prevent movement in response to a painful stimulus in 50% of patients/subjects. It is customary to use the minimum alveolar concentration, or MAC value, as a measure of drug potency. Anaesthetic agents with low MAC values are more potent
1. Nitrous Oxide and Ether: As the only organic gas practical for clinical anesthesia, Nitrous Oxide is denser than air, colourless and tasteless, but has a slightly sweet odor. Also it supports combustion as actively as oxygen and therefore flammable and thus it does not fit in the profile of a safe and undetectable gas usable in a hostage situation. Also, Nitrous has low solubility in blood and requires up to 100% concentration to induce anesthesia or unconsciousness although it has a rapid onset and recovery with minimal cardiovascular and respiratory effects. It is comparable to Ether which also has a characteristic smell which makes it unpleasant to breathe, highly volatile and explosive in Oxygen. Ether is also associated with a slow onset and a slow recovery in addition to causing irritation of the Lungs (bronchial tree) which may slow down the induction of anaesthesia and thus causes nausea and vomiting much more than any other agent.
2. Halothane (Fluothane): Halothane has a near-perfect profile of physical properties. It is well tolerated by Human body, non-irritant and adequately potent (Low MAC) since it is relatively insoluble in blood, giving rapid induction, low dose management and rapid recovery. Therefore it is known as the ideal inhalation induction agent. Cons: It is perhaps too potent and overdose is easy. It also requires that Oxygen be induced side by side to avoid hypoxia or oxygen starvation for the brain. Thus Halothane can be set aside for use in a strictly clinical setting.
3. Isoflurane: Isoflurane (and Enflurane) have a lower side effect profile and a more rapid offset of action when compared with halothane, but Isoflurane has a irritating bad smell and thus undetected induction is not possible. Also,
4. Desflurane: It needs specially designed vaporisers and thus, is not suitable for mobility which is necessary for optimum military usage.
5. Sevoflurane: It has a ultra low solubility and thus results in ultra rapid induction and at the same time, rapid recovery which is attractive for use in a hostile situation involving hostages. It is also non-irritant (like Halothane) but its sweet smell is a major obstacle to detectability and therefore disqualified for usage in a scenario similar to the Moscow Theater Crisis.
6. Valium (Diazepam): Dr. Christopher Holstege, medical toxicology director at the University of Virginia first speculated that aerosolized valium could have been used by the Russians in the Theater crisis. But it too has to be rejected. As any other benzodiazapine valium is an anti-anxiety and anticonvulsant (muscle relaxation) drug that causes only minimal sedation. Although it is possible that valium might have been used in combination with some more potent anesthetic.
7. BZ gas: Experts also mentioned BZ, or 3-quinuclidinyl benzilate, as a possibility for the gas used by the Russians. It belongs to a class of drugs known as anticholinergics that interrupt the brain's chemical messaging system between cells, leading to confusion and hallucinations. BZ takes an hour to start working and its effects peak at eight hours - whereas the Russian gas worked in seconds. Moreover, a hallucinogen seems a risky choice for terrorists strapped to bombs.
8. Opiate Derivatives: Opiods are a family of substances ranging from the well known natural opium, morphine to relatively unknown fentanyl, sufentanyl, meptazinol, etc. Most opiods make good analgesics: They are well known for their ability to reduce the perception of pain without a loss of consciousness. But for our consideration of potential military usage agents, we will concentrate on Opiate derivatives that also induce unconsciousness, such as Fentanyl.
Fentanyl citrate is one such synthetic opioid related to phenylpiperidines. It is an aqueous citrate salt of Fentanyl and can be converted into a aerosol for inhalation. Fentanyl is about 80 times as potent as morphine and brings about anaesthesia in adults with spontaneous respiration. It acts on �1 opiod receptors and thus brings in supra spinal analgesic and sedation. Its low detectability, fast but brief action makes it an attractive agent for usage in a situation similar to the Moscow theater crisis.
Moreover, its small molecular size, density and static electricity provides for easy aerolisation and usage in a wider area such as a theater or other large, but closed airspace.
However, fentanyl has some side-effects, of which nausea, vomiting, drowsiness and confusion are some. Larger doses produce respiratory depression, hypotension with circulatory failure and deepening coma. But these and the other pharmacological effects of fentanyl, can be reversed by specific narcotic antagonists (eg naloxone). The usage of Naloxone by doctors in Moscow hospitals for treatment of released hostages gave away the first clue to the correct assessment of the gas by doctors attached to the American Embassy in Moscow.
People most at risk from the effects of overdosing on opiate derivatives like fentanyl are those with pre-existing health conditions, such as chronic asthma or other serious respiratory problems, liver damage (such as in alcoholics or diabetics), various heart conditions. Stress, hunger and dehydration - all experienced by the hostages - would greatly compound any such risks.
Thus we have analysed a range of volatile agents that can induce anaesthesia or unconsciousness with reference to a set of requirements necessary for a particular agent to qualify as ideal or near-ideal for use in a Terrorist situation involving captors holding hostages inside a closed building, hereby neutralising both the captives and their terrorist captors, enabling a quick commando action by elite forces to free the hostages and kill or capture the terrorists.
The Moscow theater hostage drama and the subsequent Russian response has demostrated the need for Law enforcement bodies around the world involved in counter-terrorism activities to actively pursue programs for research and integration of chemical agents usage to traditional methods of hostage crisis resolutions.
SOURCES AND FURTHER READING
1)
http://in.news.yahoo.com/021025/137/1wxhr.html
2)
http://www.bayarea.com/mld/bayarea/news ... 370982.htm
3)
http://story.news.yahoo.com/news?tmpl=s ... iege_dc_65
4)
http://story.news.yahoo.com/news?tmpl=s ... &printer=1
5)
http://www.alertnet.org/thenews/newsdesk/L30350073
6)
http://www.boston.com/news/daily/30/russia_gas.htm
7)
http://terra.nasa.gov/FactSheets/Aerosols/
8)
http://www.aerosol-soc.org.uk/aerosols.asp
9)
http://www.biral.com/aerosol/aerosolgeneration.htm
10)
http://www.milparade.com/1998/26/046.htm
11)Harrison's Principles of Internal Medicine, Isselbacher et al; McGraw-Hill, 1994.
12)Clinical Pharamacology, Laurence and Bennett, Churchill Livingstone, 1993.
13)Textbook of Medical Physiology, Guyton, WB Saunders, 1986.