Effects of partial plasma exchange transfusion on blood flow velocity in large arteries of arm and leg, and in cerebral arteries in polycythaemic newborn infants

Abstract

Continuous wave Doppler velocimetry was performed in brachial, femoral and cerebral arteries in four preterm, four small-for-gestational-age (SGA) and eight appropriate-for-gestational age (AGA) polycythaemic newborns before and at 3 and 24 h after partial plasma exchange transfusion and in 18 matched controls at 3 and 24 h after birth. In peripheral arteries, end-diastolic flow velocity was zero in all eight AGA controls, but only in two of the other infants. Consequently, mean flow velocity and red cell transport in AGA controls were significantly lower than in the other five groups, which did not differ. Partial plasma exchange transfusion did not influence flow velocities and red cell transport in peripheral arteries, but normalized the flow velocities in cerebral arteries in all three subgroups of polycythaemic infants, which were lower than in control infants. Cerebral red cell transport in controls increased significantly between 3 and 24 h, and in polycythaemic infants between 0 and 3 h after partial plasma exchange transfusion. In conclusion, reduction in haematocrit had different effects on blood flow velocity and red cell transport of peripheral and cerebral vessels, suggesting that the increased cerebral blood flow velocity after partial plasma exchange transfusion is not simply due to a reduction in viscosity or oxygen content of the blood. The lower peripheral blood flow velocities in normocythaemic AGA infants as compared to all other groups, suggest that the level of maturity is an important determinant for the capacity to regulate blood flow.

Review of the correlation between blood flow velocity and polycythemia in the fetus, neonate and adult: appropriate diagnostic levels need to be determined for twin anemia-polycythemia sequence

“…Our search identified six studies, including a total of 96 neonates, documenting the relationship between polycythemia and cerebral blood flow or velocity in the neonatal population (Table ). Two studies with 21 neonates specifically examined MCA flow velocity: Weissman et al evaluated five polycythemic neonates of a cohort of 151 and showed a significantly lower MCA‐PSV in the polycythemic group than in controls.…”

“…Two studies with 21 neonates specifically examined MCA flow velocity: Weissman et al evaluated five polycythemic neonates of a cohort of 151 and showed a significantly lower MCA‐PSV in the polycythemic group than in controls. Maertzdorf et al evaluated 16 polycythemic neonates undergoing partial plasma exchange transfusion, and demonstrated a clear increase in MCA‐PSV with hemodilution. Five further studies with 91 neonates examined velocity in the anterior communicating, internal carotid and unspecified cerebral arteries.…”

“…Maertzdorf et al evaluated 16 polycythemic neonates undergoing partial plasma exchange transfusion, and demonstrated a clear increase in MCA‐PSV with hemodilution. Five further studies with 91 neonates examined velocity in the anterior communicating, internal carotid and unspecified cerebral arteries. All five studies demonstrated an increase in cerebral blood vessel velocity corresponding with hemodilution after partial plasma exchange transfusion.…”

“…Two studies with 21 neonates specifically examined MCA flow velocity: Weissman et al 29 evaluated five polycythemic neonates of a cohort of 151 and showed a significantly lower MCA-PSV in the polycythemic group than in controls 29 . Maertzdorf et al 27 Two studies including 25 neonates used spectroscopy to correlate polycythemia with change in cerebral Only first author of each study is given. MoM, multiples of the median.…”

“…A further study was identified that measured MCA velocity in a range of patients, demonstrating an increase in MCA flow velocity with hemodilution but not identifying which patients were polycythemic 42 . Conversely, Brass et al 43 demonstrated an increase in MCA-PSV in adults corresponding with anemia, but did not include 27 16 Increase in MCA velocity after partial exchange transfusion Weissman (2012) 29 5…”