Sterilization kills or renders inactive all microbial organisms. The common methods used are steam heat, ethylene oxide gas or chemicals. Any item used for survival surgery, ie. instruments, catheters, flow probes, or electrodes and fluids used for flushing or injection must be sterilized. Special care is needed to ensure that multi-dose vials of drugs are not outdated or contaminated. Packs of sterile instruments or materials that are to be stored for more than a week, should be double wrapped in packaging which is impermeable to water. The date of sterilization should be clearly marked on the outer wrapper. Expiration dates vary with packaging materials, but a general guideline is 2 months from the date of sterilization. Commercially available plastic dust covers will extend the shelf life to 6-12 months.
Available methods of sterilization include steam heat, ethylene oxide gas, glass bead, and chemical agents. Glass bead sterilizers will sterilize only the portion of the instrument placed in the beads. Chemical agents include glutaraldehyde, phenols, and chlorine dioxide but all have serious drawbacks: glutaraldehyde is mutagenic, phenols are corrosive and both require special disposal procedures; chlorine dioxide has a short sterilizing useful life (1 day) and is corrosive to metals. All chemical agents require rinsing with sterile solutions prior to tissue contact. The effectiveness of chemical sterilizing agents is currently under review by various government agencies and it appears that the manufacturers' recommendations will change.