Anaemia and massive bleeding apart from the aspect of oxygenation.

A strong distinction must be made between the following situations of anaemia: Under chronic conditions, i.e. anaemia with a reduced Hb concentration (cHb), normovolaemia is given and, therefore, the patient’s acid-base balance is not impaired. Oxygen supply as well as tissue oxygenation is suffi cient, partly as a result of the right shifted oxygen binding curve (increase in 2,3-DPG), down to a cHb of ~5 g/dl. In the case of acute conditions, however, haemodilution during massive bleeding leads to a decrease in cHb, in which case we may be faced with two diff erent scenarios: Either normovolaemia as a result of an optimal therapy with normal acid-base balance, especially lactate concentration (cLact), or hypovolaemia with a compromised tissue oxygenation and resulting acidosis, mostly lactic acidosis, despite the right shifted oxygen binding curve (decrease in pH). Th is acidosis is, in addition to hypothermia, the cause of the coagulopathy which, in turn, favours further bleeding, the so-called “lethal triad” demonstrated with about 80 thousand patients by Martin et al. in 2005 [1]. In about 8200 multiple trauma patients, a strong correlation has been shown between mortality (%) and base excess (BE, mmol/L) on hospital admission alone (4 studies) [2]: A base defi cit (BD) of ~15 mmol/L predicts a mortality of ~50%. Aggressive management of the “lethal triad”, i.e. coagulopathy as a result of metabolic acidosis plus hypothermia, therefore, appears to have the greatest potential of reducing mortality in severely injured patients [3].