One of the more frequently used treatment schedules is the US Navy Table 6, which provides hyperbaric oxygen therapy with a maximum pressure equivalent to 60 feet (18 m) of seawater (2.8 bar PO2) for a total time under pressure of 288 minutes, of which 240 minutes are on oxygen and the balance are air breaks to minimise the possibility of oxygen toxicity.A multiplace chamber is the preferred facility for treatment of decompression sickness as it allows direct physical access to the patient by medical personnel, but monoplace chambers are more widely available and should be used for treatment if a multiplace chamber is not available or transportation would cause significant delay in treatment, as the interval between onset of symptoms and recompression is important to the quality of recovery. It may be necessary to modify the optimum treatment schedule to allow use of a monoplace chamber, but this is usually better than delaying treatment. A US Navy treatment table 5 can be safely performed without air breaks if a built-in breathing system is not available. In most cases the patient can be adequately treated in a monoplace chamber at the receiving hospital. Altitude decompression sickness
Treatment and management may vary depending on the grade or form of decompression sickness and the treating facility or organization. First aid at altitude is oxygen at the highest practicable concentration and earliest and largest practicable reduction in cabin altitude.
The chlorine group at the 6-position of the heterocyclic ring is more reactive than the chlorine at the 2-position, hence it can be selectively replaced by an amino group, which was then converted to an amide using nitrous acid. Finally, the remaining chlorine was replaced by the amino group of aciclovir using ammonia in methanol. This synthesis and other methods for preparing the compound have been reviewed. History
Aciclovir was seen as the start of a new era in antiviral therapy, as it is extremely selective and low in cytotoxicity. Since discovery in mid 1970s, it has been used as an effective drug for the treatment of infections caused by most known species of the herpesvirus family, including herpes simplex and varicella zoster viruses. Nucleosides isolated from a Caribbean sponge, Cryptotethya crypta, were the basis for the synthesis of aciclovir. It was codiscovered by Howard Schaeffer following his work with Robert Vince, S. Bittner and S. Gurwara on the adenosine analog acycloadenosine which showed promising antiviral activity. Later, Schaeffer joined Burroughs Wellcome and continued the development of aciclovir with pharmacologist Gertrude B. Elion. A U.S. patent on aciclovir listing Schaeffer as inventor was issued in 1979. Vince later invented abacavir, an nRTI drug for HIV patients. Elion was awarded the 1988 Nobel Prize in Medicine, partly for the development of aciclovir. A related prodrug form, valaciclovir came into medical use in 1995.