Figure 1.
Inclusion and exclusion criteria.
Figure 2.
Flow diagram of identification and retrieval of examined studies.
Table 1.
Characteristics of included studies.
Table 2.
Critical appraisal of included studies.
Table 3.
Association between blood loss and changes in vital signs.
Table 4.
Clinical signs assessment and blood loss estimation method.
Table 5.
Clinical signs statistical analysis.
Table 6.
Clinical signs associated to mortality in included studies.