PMID- 90967 OWN - NLM STAT- MEDLINE DCOM- 19791229 LR - 20190610 IS - 0140-6736 (Print) IS - 0140-6736 (Linking) VI - 2 IP - 8148 DP - 1979 Oct 27 TI - Cerebral blood-flow and viscosity in relative polycythaemia. PG - 873-7 AB - Cerebral blood flow (CBF), red-cell mass, and plasma volume were measured in 39 patients with venous haematocrit values in the range 0.47--0.58. Patients with true polycythaemia were thus excluded. The 39 patients studied fell into two groups--those with a measured red-cell mass in the high-normal range and those with normal red-cell-mass values but reduced plasma-volume values (the relative-polycythaemia, low-plasma-volume group). The mean CBF was low in both the high-normal red-cell-mass (HNRCM) group (45.8 ml/100 g/min) and low-plasma-volume (LPV) group (48.8 ml/100 g/min). The haematocrit in the HNRCM group was 0.504 and in the LPV group 0.513. In a control group of subjects with a mean haematocrit of 0.421 CBF was 68.6 ml/100 g/min. Venesection was associated with a significant rise in CBF in both groups of patients--to 59.7 ml/100 g/min in the HNRCM group and 65.0 ml/100 g/min in the LPV group. Whole-blood viscosity fell significantly in both groups. Both groups demonstrated significant inverse relationships between CBF and haematocrit and between CBF and blood viscosity. FAU - Humphrey, P R AU - Humphrey PR FAU - Du Boulay, G H AU - Du Boulay GH FAU - Marshall, J AU - Marshall J FAU - Pearson, T C AU - Pearson TC FAU - Russell, R W AU - Russell RW FAU - Symon, L AU - Symon L FAU - Wetherley-Mein, G AU - Wetherley-Mein G FAU - Zilkha, E AU - Zilkha E LA - eng PT - Journal Article PL - England TA - Lancet JT - Lancet (London, England) JID - 2985213R SB - IM MH - Adult MH - Aged MH - *Blood Viscosity MH - Bloodletting MH - *Cerebrovascular Circulation MH - Erythrocyte Volume MH - Hematocrit MH - Humans MH - Middle Aged MH - Plasma Volume MH - Polycythemia/blood/*physiopathology EDAT- 1979/10/27 00:00 MHDA- 1979/10/27 00:01 CRDT- 1979/10/27 00:00 PHST- 1979/10/27 00:00 [pubmed] PHST- 1979/10/27 00:01 [medline] PHST- 1979/10/27 00:00 [entrez] AID - S0140-6736(79)92687-4 [pii] AID - 10.1016/s0140-6736(79)92687-4 [doi] PST - ppublish SO - Lancet. 1979 Oct 27;2(8148):873-7. doi: 10.1016/s0140-6736(79)92687-4.