Effect of vecuronium on intracranial pressure, mean arterial pressure and heart rate in cats.

The effect of vecuronium on intracranial pressure (ICP) was investigated in six cats with normal and increased ICP. Cats were anaesthetized with pentobarbitone 33 mg kg-1 i.p. and acepromazine 0.6 mg kg-1 i.p., the trachea was intubated, and the lungs ventilated with nitrous oxide in oxygen. Mean arterial pressure (MAP), heart rate (HR), twitch response and ICP were recorded continuously. After the effect of vecuronium had been ascertained under the condition of normal ICP, and after full recovery of twitch response, pH-adjusted Ringer's lactate solution was infused to the cisterna magna until an ICP baseline of 26 +/- 2 mm Hg was established, and had stabilized. Vecuronium was administered again to determine its effect under the condition of increased ICP. Complete ablation of twitch response was obtained in 68 +/- 15 s with vecuronium 80 micrograms kg-1, and there was no significant change in ICP, MAP, HR or cerebral perfusion pressure (CPP) under either ICP condition.