COL Prof. Dr. Horst Thiermann
Future Forces Forum Future Forces Exhibition 2016 Medical Workshop 2016
Chief of Institute
Bundeswehr Institute of Pharmacology and Toxicology
Nerve Agent Poisoning: Intensive Research is Necessary to Close Existing Therapeutic Gaps
Most recently, the director general of the organisation for the prohibition of chemical weapons expressed his serious concerns about “recent reports of possible use of chemical weapons” in the Middle East conflict area. Indeed, there was a huge number of victims in 2013 after release of the nerve agent Sarin in Syria. Hence, it has to be discussed how the available therapeutic strategies, in particular for nerve agent poisoning, can be optimized. Generally, nerve agents include highly volatile G-agents, e.g. sarin, which exert their toxic effect very fast after inhalation exposure and persistent V-agents, which pose a specific threat by percutaneous exposure, showing a delayed onset of signs and symptoms which may persist for a remarkable long period. Hence, medical personal needs adequate protection to prevent secondary contamination. Although nerve agent induced cholinergic crisis presents comparably specific, the events in Syria showed great diagnostic uncertainty during early care. Without verifying the used nerve agent, inhibition of red blood cell acetylcholinesterase is indicative for poisoning by organophosphorus compounds. Thus, this parameter, which can be assayed on-site, easily could confirm clinical diagnosis. Standard therapy consists of the administration of atropine, an oxime, benzodiazepine and may also include supportive care, e.g. artificial ventilation. While the importance of aggressive atropinisation is undoubted, there is some dispute on the use of oximes. Generally, in military scenarios in which doses of up to 5 times LD50 are expected, effective oximes should be effective when administered rapidly, at adequate dose and for required duration. An elaborated system, the cholinesterase status is available, to assess the necessary parameters at early stages of care. Unfortunately, however, poisoning by several nerve agents cannot be treated successfully with oximes at present and the critical neuromuscular block, in particular at the respiratory muscle, may result in respiratory arrest. Current approaches to prevent inhibition of cholinesterase in the body by scavengers will be discussed. An alternative approach consists in restoration of neuromuscular function in spite of acetylcholine excess by antinicotinics. Recent experimental results will be shown, indicating that this approach may be an option for the future.
Colonel (MC) Prof. Dr. Horst Thiermann studied medicine at the University of Regensburg and Technical University, Munich. After working in the Bundeswehr Hospital Munich in the departments of anaesthesiology and surgery, he changed to the Bundeswehr Institute of Pharmacology and Toxicology. He specialized in Pharmacology and Toxicology at the Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig Maximilians-University Munich in 1996. In 2002, he completed his advanced studies of Clinical Pharmacology at MDS Pharma Services, Höhenkirchen-Siegertsbrunn. Since November 2006 he is in charge of the Bundeswehr Institute of Pharmacology and Toxicology. In January 2012 he was appointed Professor at Technical University, Munich. Colonel (MC) Prof. Dr. Thiermann is vice-chairman of Bundesinstitut für Risikobewertung (BfR) Committee for the Assessment of Intoxications, member of the board and scientific committee of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) and past president of Clinical and Translational Toxicology Speciality Section (CTTSS) of the Society of Toxicology (SOT).