Table 1

Historical development of hemorrhagic shock models with oxygen debt as an end-point
Author (year) [ref.]	Model	Method	Result

Crowell and Smith (1964) [4]	Dog	Hypotension of 30 mmHg; various oxygen deficits were allowed to accumulate	O₂D as an indicator of survival
Rush et al. (1965) [5]	Dog	30 min hemorrhage with varying hemorrhage volumes; achieved O₂D varied	O₂D as an indicator of cardiovascular change; the end-point 'survival' was not evaluated
Goodyer (1967) [90]	Dog	Hypotension of 30–50 mmHg; various oxygen deficits were allowed to accumulate	Irreversibility of shock is determined by peripheral mechanisms; the end-point'survival' was not evaluated
Jones et al. (1968) [7]	Dog	Hypotension of 30 mmHg; an oxygen deficit of120 cm³/kg was allowed to accumulate	O₂D as an indicator of survival
Rothe (1968) [6]	Dog	Hypotension of 30 mmHg; various oxygen deficits were allowed to accumulate	No correlation betweeen O₂D and survival
Neuhof et al. (1973) [8]	Rabbit	30 min hemorrhage (1 ml/kg per min); achieved O₂D varied	O₂D as an indicator of survival
Schoenberg et al. (1985) [21]	Dog	Hypotension of 30 mmHg; various oxygen deficits were allowed to accumulate	No correlation betweeen O₂D and survival
Reinhart et al. (1989) [91]	Dog	Hypotension of 40 mmHg; various oxygen deficits were allowed to accumulate	Excess oxygen uptake in recovery with hydroxyethylstarch; the end-point 'survival' was not evaluated
Dunham et al. (1991) [9]	Dog	Predetermined O₂D after 60 min; independent of blood pressure or hemorrhage volume	O₂D as an indicator of survival and O₂D probability of death defined for dog
Sheffer et al. (1997) [92]	Computer	Computer simulation of myocardial oxygen deficit	For hemorrhage of 100 ml/min: time interval from injury to cardiac O₂D inversely related to infusion rate; the end-point 'survival' was not evaluated
Siegel et al. (1997) [43]	Dog	Predetermined O₂D after 60 min; independent of blood pressure or hemorrhage volume	Superiority of recombinant hemoglobin over colloid or whole blood in resuscitation
Rixen et al. (2001) [44]	Pig	Predetermined O₂D after 60 min; independent of blood pressure or hemorrhage volume	O₂D as an indicator of survival and O₂D probability of death defined for pig.
Siegel et al. (2003) [37]	Dog	Predetermined O₂D after 60 min; independent of blood pressure or hemorrhage volume	Determination of critical level of partial resuscitation as 30% of blood volume loss to return O₂D to survival levels without vital organ cellular injury

O₂D, oxygen debt.
Rixen and Siegel Critical Care 2005 9:441 doi:10.1186/cc3526