The Effects of High Dose Methylprednisolone or Fluid Volume Expansion on Cerebral Haemo‐dynamics and Oxygen Uptake in Endotoxic Shock. An Experimental Study in Dogs

E coli endotoxin has been shown to decrease cerebral blood flow (CBF) and increase cerebral metabolic rate of oxygen (CMRO2) in normocapnic dogs. The aim of this study was to investigate the effects of different clinical treatments on the cerebral and central circulation already under the influence of endotoxin. Thus the animals were treated with either methylprednisolone or a lactated Ringer's solution. CBF, CMRO2 and intracranial pressure were followed. Central haemodynamic parameters, i.e. cardiac output, aortic pressure and pulmonary artery pressure, were also measured. Five dogs were given methylprednisolone (Solu-Medrol) 30 mg/kg 90 min after the endotoxin injection. Following this drug there were no significant changes in CBF when compared to controls. The primarily increased CMRO2 did, however, show a transient decrease. Five animals were treated with a lactated Ringer's solution. (Ringerdex), 30 mg/kg, given intravenously over 20 min starting 90 min after the endotoxin injection. In these animals, the cardiac output as well as CMRO2 returned to the values before endotoxin. CBF did not increase significantly.