Avaliação da resposta laboratorial, hemodinâmica e do fluxo sanguíneo tecidual no choque hemorrágico não controlado em ratos sem roposição volêmica e após reposição volêmica, nas modalidades normotensiva e hipotensão permissiva

Abstract

Background: Permissive hypotension decreases blood loss in hemorrhagic shock. Concerns have been raised about organ perfusion with that strategy. We set forth to investigate regional organ perfusion with fluorescent microspheres during hemorrhagic shock treated with permissive hypotension and normotensive resuscitation. Methods: Male rats (n = 45) randomized to 4 groups: sham, no fluid (NF), permissive hypotension (PH) (60% of baseline mean arterial pressure - MAP), normotensive resuscitation (NBP). Uncontrolled hemorrhagic shock caused by a standardized injury; hemodynamic parameters were monitored continuously and lactated Ringers was infused to maintain MAP 60% of basal levels (PH) or near those (NBP). Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after shock, as well as, hemogram, lactic acid, cardiac output and blood loss. Intra-abdominal blood loss was assessed. Analysis of variance with Tukey post test was used for comparison. Results: Intra-abdominal blood loss was greater in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical difference in lactic acid levels between PH and NBP groups. NF animals had worse organ perfusion and higher lactic acidosis. No difference in organ perfusion between PH and NBP groups.Conclusions: PH resulted in less intra-abdominal bleeding than normotensive resuscitation after hemorrhagic shock. Organ perfusion assessed by fluorescent microspheres showed no difference in organ perfusion between PH and NBP resuscitation. NF group animals had low intra-abdominal bleeding, but worse organ perfusion.