These models, such as the Bühlmann decompression algorithm, are modified to fit empirical data and provide a decompression schedule for a given depth and dive duration using a specified breathing gas mixture.Since divers on the surface after a dive may still have excess inert gas in their bodies, decompression from any subsequent dive before this excess is eliminated needs to modify the schedule to take account of the residual gas load from the previous dive. This will result in a shorter allowable time under water without obligatory decompression stops, or an increased decompression time during the subsequent dive. The total elimination of excess gas may take many hours, and tables will indicate the time at normal pressures that is required, which may be up to 18 hours.Decompression time can be significantly shortened by breathing mixtures containing much less inert gas during the decompression phase of the dive (or pure oxygen at stops in 6 metres (20 ft) of water or less). The reason is that the inert gas outgases at a rate proportional to the difference between the partial pressure of inert gas in the divers body and its partial pressure in the breathing gas; whereas the likelihood of bubble formation depends on the difference between the inert gas partial pressure in the divers body and the ambient pressure.
Anaphylaxis

Prevention
To prevent allergic transfusion reaction it is possible to use patients own blood for transfusion, this is referred to as autologous blood transfusion. Patients own blood is collected and washed to produce concentrated red blood cells (this blood product is also called packed red blood cells). There are multiple ways to wash red blood cells. The two main methods that are used to wash the cells are centrifugation, or filtration methods like the Hemoclear microfilter. The last option is reinfusion without washing. This is the least preferred method because of the chance of complications.There is no evidence that antihistamine premedication prevents allergic transfusion reactions, although these drugs can mitigate symptoms once they occur. Treatment
Treatment of an allergic transfusion reaction is to immediately stop the transfusion. If the only symptoms are mild (i.e., hives and itching), the patient may be treated with an antihistamine and if the symptoms completely disappear and the patient feels well, the transfusion may be restarted. A mild transfusion reaction during infusion usually does not progress to a more severe anaphylactic reaction after infusion of additional product from the same unit. If the symptoms are more than mild, the transfusion should not be restarted. == References ==