Target blood pressure for hypotensive resuscitation

Background

Good outcomes have resulted from hypotensive resuscitation of hemorrhagic shock patients. We hypothesized that mean arterial pressure (MAP) 60 mmHg is the target blood pressure for hypotensive resuscitation during uncontrolled hemorrhagic shock in trauma.

Methods

To determine the effective target MAP for hypotensive resuscitation during uncontrolled hemorrhagic shock, we randomly assigned 80 rats to one of 8 treatment groups (n = 10 for each group). We then observed the effects of different target MAPs (control, 40, 50, 60, 70, 80, 90 mmHg, and sham) on fluid resuscitation of uncontrolled hemorrhagic shock. Blood pressure, serum lactate, hematocrit, fluid therapy, blood loss, and plasma cytokine levels were measured at 0, 30, 90, 120, 180, 240, 300 min after the start of the surgical procedure.

Results

A target MAP of 90, 80 and 70 mmHg had increased blood loss and decreased hematocrit and IL-6 and TNF-α production. A target MAP of 60, 50 and 40 mmHg had lower blood loss, good hematocrit, higher IL-6 and TNF-α production, and decreased animal survival. Only target MAPs of 40 and 50 had and decreased animal survival. The differences in blood loss, hematocrit, lactate, post-resuscitation MAP, survival, IL-6, IL-10, and TNF-α production between rats with a target MAP of 60 mmHg and those with a target MAP of 70 mmHg were not significant. The amount of fluid therapy in the BP 60 groups was less than in the BP 70 groups (P < 0.001).

Conclusion

A MAP of 60 mmHg should be considered for evaluation in human studies as a target for hypotensive resuscitation.