[Experimental studies on the intracranial pressure increase by ketamine in haemorrhagic shock (author's transl)].

In 12 normocapnic ventilated dogs the intracranial pressure (ICP) was increased 3-4 fold by distension of the balloon of a Foley catheter (imitating a space occupying lesion). Thereafter a shock state (aortic pressure PsA 80 mm Hg) over 20 min was induced by arterial bleeding. ICP and more pronounced cerebral perfusion pressure (CPP) decreased. Injection of Ketamine 0.5 mg/kg b.w. was followed by a transient increase of PsA (mean 10 mm Hg), ICP (mean 2,6 mm Hg) and cerebral perfusion pressure (mean 3,9 mm Hg). After ketamine 5.0 mg/kg v.w. PsA, ICP and CPP decreased. Retransfusion of the withdrawn blood volume (44 ml/kg b.w.) caused a significant increase of PsA, ICP and CPP to near control levels. A further increase of PsA, ICP and especially CPP was seen after ketamine 1,0 mg/kg b.w. Based on this study it should be possible to use ketamine in small dose for induction of anaesthesia in the emergency of haemorrhagic shock even in head injury patients with increased ICP. There is no further serious increase in ICP.