Cerebral effects of three resuscitation protocols in uncontrolled haemorrhagic shock: a randomised controlled experimental study.

BACKGROUND: To compare haemodynamic and cerebral variables during aggressive fluid resuscitation vs. administration of a hypertonic starch solution (HS) combined with either noradrenaline [norepinephrine] or arginine vasopressin in an animal model of uncontrolled haemorrhagic shock.

METHODS: After Animal Investigational Committee approval, 24 anaesthetised pigs underwent a liver trauma. At haemodynamic decompensation, animals were randomly assigned to receive fluid resuscitation (6% HES 130/0.4, 20 mL/kg, and Ringer, 40 mL/kg; FR group, n=8), or noradrenaline (bolus 20 microg/kg, continuously 1 microg/kg/min) combined with HS (7.2% NaCl/6% HES 200/0.5; 4 mL/kg) (n=8; NA/HS group), or vasopressin (bolus 0.2U/kg, continuously 0.04 U/kg/min) combined with HS (4 mL/kg) (n=8; AVP/HS group), respectively. Thirty minutes after drug administration, bleeding was controlled manually.

RESULTS: Mean arterial blood pressure (MAP), cerebral perfusion pressure (CPP), and brain tissue oxygen pressure (P(bt)O(2)) decreased significantly with haemorrhage in all groups (p<0.05). AVP/HS resulted in a faster and higher increase of MAP and CPP compared to both NA/HS and FR (p<0.001 vs. FR; p<0.01 vs. NA/HS). Compared to FR, P(bt)O(2) increased faster with AVP/HS and NA/HS (p<0.05) after therapy, and ICP was lower at the end of the study period (p<0.05). All animals (8/8) of the AVP/HS group survived, compared to 4/8 and 4/8 in the NA/HS and FR group, respectively (p=0.07).

CONCLUSIONS: Following uncontrolled haemorrhagic shock in this animal model, combination of HS with arginine vasopressin increased CPP and cerebral oxygenation faster than aggressive fluid resuscitation, without re-increasing ICP.