Current shock models and clinical correlations.

No useful purpose is served by developing therapeutic interventions that are applicable only in nonexistent patient populations. The history of laboratory hemorrhagic shock research may be a case in point because although many interventions have been proposed on the basis of animal experimentation, few if any have found a place in the treatment of human beings. For a laboratory shock model to have clinical relevance, it must replicate important aspects of shock as seen in human beings during or following massive blood loss. The difficulty in developing an animal model that incorporates these human aspects--hypothermia, hypoxia, hypotension, acidosis, coagulopathy, etc--must not be underestimated. Four methodological factors to consider are animal species, anesthesia, tissue trauma, and nociceptive effects. The development of an animal shock model will require several compromises and the results, whether dealing with mechanisms or therapeutic outcomes, must be considered suspect until confirmatory data are obtained from human studies.