Arachnoid clearance of red blood cells

Abstract

SYNOPSIS Labelled red blood cells were instilled intraventricularly in groups of dogs and monkeys for evaluation of transfer to the vascular compartment. Blood levels were minimal (500 of the original material) with low-pressure infusions. A large movement (above 25%) of the type originally described by Simmonds occurred with high-pressure intraventricular infusions, cisternal injections, or after the induction of intracranial hypertension. Large amounts of the label were released after cell lysis and accumulated in various tissues. Five to ten per cent of the instilled material was absorbed by the nasal lymphatic route in the dog and a significant local loss of red cells occurred after posterior cisternal punctures. Simulated whole blood was useful in demonstrating arachnoid retention. Ventriculospinal washouts aided in the elimination of tagged cells only in the first 24 hours. Thereafter, the yield was small and the fluid requirement was unusually high.Unusually large variations in the movement of red cells from the subarachnoid space to the blood stream have been reported. The initial work of Simmonds indicated the transfer of approximately 15% of cisternal blood deposits (Simmonds, 1952(Simmonds, ,1953. Other later studies disclosed a range extending from 2-66% (Adams and Prawirohardjo, 1959;Dupont et al., 1961;Bradford and Johnson, 1962). In this work, we have re-evaluated the removal of subarachnoid blood by (1) testing the influences of hydrostatic force and of lavage, (2) measuring the uptake of radioactive label in various tissues, and (3)

Differentiation of early subarachnoid hemorrhage from traumatic lumbar puncture.

“…Though these values were independent both of the time after subarachnoid hemorrhage and of the magnitude of rbc count in the CSF, higher values tended to occur somewhat more frequently at the longer time intervals (table 1). Since generally lower rbc counts were also observed at these longer time intervals, despite the original introduction of equal volumes of autologous blood, the higher values probably reflect the sequestration of blood in the subarachnoid space 8 ' " rather than a greater quantity of lysed rbc's. Rbc counts varied from 14,200 to 1,100,000 rbc/mm» for all experiments.…”

“…8 If other sources of lactate can be excluded, lactate concentration in hemorrhagic CSF should increase as a function of time following the onset of a subarachnoid hemorrhage, 4 -• whereas the lactate concentration in the spinal fluid obtained from a "traumatic tap" should be identical with that of uncontaminated fluid if determined immediately.…”

Scanning electron microscopy of the subarachnoid space in the dog: Inflammatory response after injection of defibrinated chicken erythrocytes

“…Past studies document the reaction of the SAS after the injection of homologous (Bradford and Johnson, 1962;Maiorova, 1965), autologous (Shabo and Maxwell, 1971;McQueen et al, 1974;Krahn, 1977;Suzuki et al, 1977, 19791, and heterologous (Maiorova, 1965;Oehmichen, 1976) whole blood or its components (erythrocytes and plasma proteins). Most of these studies investigated the passage of erythrocytes from the SAS to the systemic circulation.…”