Gregersen also notes that hemorrhage has been “widely
employed”and “anincreasingnumberof thesestudies has
beendonewithoutthecomplicatingfactorofanesthesia.”He
isnot,however,pleasedbyallthisdiversity,andcomplains
thatthevarietyofmethodsmakesit“exceedinglydifficult”to
evaluatetheresultsofdifferentresearchers;thereis,hesays,
a “crying need”
for standardized procedures that will invariablyproduce a
state of shock.^88
Eightyearslaterthesituationhadnotchangedmuch.S.M.
Rosenthal and R. C. Millican wrote that “animal
investigationsin the fieldof traumatic shock haveyielded
diversifiedandoftencontradictoryresults.”Neverthelessthey
lookedforwardto“futureexperimentationinthisfield”and
likeGregersentheydiscouragedtheuseofanesthesia:“The
influence of anesthesia is controversial ... [and] in the
reviewers’opinionprolongedanesthesiaisbestavoided....”
Theyalsorecommendedthat“adequatenumbersofanimals
must be employed to overcome biological variations.”^89
In 1974 experimenterswerestillworkingon“animalmodels”
of experimental shock, still carrying out preliminary
experimentstodeterminewhatinjuriesmightbeinflictedto
produce a satisfactory “standard” state of shock. After
decadesofexperimentsdesignedtoproduceshockindogsby
causingthemto hemorrhage, morerecent studies indicated
that(surprise!)hemorrhage-inducedshockindogsisnotlike
shock in humans. Noting these studies, researchers at the
Universityof Rochestercaused hemorrhage in pigs,which
they think may be more like humans in this respect, to
determinewhatvolumeofbloodlossmightbesuitableforthe
production of experimental shock.^90