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.