Figure 64-3 Chemical formulas of organophosphate nerve agents: tabun (GA) (A); sarin (GB) (B); soman (GD) (C); and VX (D). (From Baker DJ: Anesthesia in extreme environmental conditions. Part 2. Chemical and biologic warfare. In Grande CG [ed]: Textbook of Trauma Anesthesia and Critical Care. Baltimore, Mosby-Year Book, 1993, p 1331.)