Additional colloids have only a minor haemodilutive effect after surgery for aneurysmal subarachnoid haemorrhage

Haemodilution is commonly used as prophylaxis, as well as treatment for cer ebral ischaemia after aneurysmal subarachnoid haemorrhage (SAH). Thirty six patients operated for aneurysmal SAH were evaluated retrospectively; 24 re ceived haemodilutive therapy and 12 patients, as a control group, received no additional therapy. There was a 'spontaneous' drop in haematocrit by 22% in both groups, and a corresponding drop in haemoglobin by 23% in the trea tment group and 19% in the non-haemodiluted group, during the first 4 days after the SAH. After the initial decrease the haematocrit remained stable b etween 0.28 and 0.33 until day 14 in both groups. The haemodilutive group h ad only a minor lower haematocrit level during days 8-12 as the additional fluid resulted in increased renal excretion. This minor difference was, how ever, significant (p<0.02).