The effects of 10 degrees reverse trendelenburg position on ICP and CPP in prone positioned patients subjected to craniotomy for occipital or cerebellar tumours.

Abstract

Control of ICP-hypertension is of utmost importance during craniotomy. The effects of reverse Trendelenburg position (RTP) upon ICP and CPP have recently been studied in supine positioned patients. In this study we investigated changes in intracranial pressure (ICP), mean arterial blood pressure (MABP), CPP and jugular bulb pressure (JBP) before and one minute after 10( degrees ) RTP in 26 prone positioned patients with either occipital (n=12) or cerebellar tumours (n=14). ICP was measured by a subdural approach after removal of the bone flap. Tension of the dura was estimated by the surgeons by digital palpation before and after change in position. In patients with occipital tumours ICP decreased from 21.0 to 15.6 mm Hg (p<0.05). MABP decreased from 87.9 to 83.3 mm Hg (p<0.05), JBP decreased from 14.3 to 7.7 mm Hg (P<0.05), while CPP was unchanged. In patients with cerebellar tumours ICP decreased from 18.3 to 14.2 mm Hg (p<0.05). MABP decreased from 93,8 to 90.5 mm Hg (p<0.05), JBP decreased from 12.1 to 5.0 mm Hg (P<0.05), while CPP was unchanged. There were no significant differences between the two groups with regard to changes in ICP, MABP, CPP and JBP. The change in ICP was accompanied by a significant decrease in dural tension (p<0.05). In prone positioned patients 10 degrees RTP significantly reduces ICP, JPB and MABP within one minute, while CPP is unchanged.