Effects of epidural and halothane anaesthesia on vasoconstrictive properties of cell-free haemoglobin

Introduction

In the moment haemoglobin based oxygen carries (HBOC) are under clinical investigation. Only few studies looked for the interactions between anaesthetic drugs and HBOC. The effects of HBOC during regional anaesthesia have never been analysed. Therefore, we investigated the hemodynamic changes after HBOC infusion during different kinds of anaesthesia.

Methods

Sheep were assigned to three different groups: a) 6 not anaesthetised sheep, b) 6 sheep with a halothane anaesthesia (2.0 Vol. % in oxygen), c) 6 sheep had an thoracic epidural anaesthesia with bupivacaine. After a stabilisation period all 18 animals received an i.v. bolus of 100 mg Pyridoxalated Haemoglobin Poly-oxyethylene Conjugate/kg.

Results

The vasoconstrictive effects of a HBOC were similar in awake sheep and in sheep with epidural anaesthesia. Anaesthesia with halothane reduced the effects on mean arterial pressure and cardiac index but did not abolish the pulmonary vasoconstriction.

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Conclusion

The selection of the anaesthesia method may alter hemodynamic side effects of HBOC.