[Hb] values were determined by the cyanmethemoglobin
method, using a hemoglobinometer
LK 540 (Swelab, Stockholm). A mixture
of 20 ~1 blood and 5 ml Drabkin’s solution was
allowed to stabilize for 5 min; thereafter, it was
centrifuged at 3000 r.p.m. for 5 min. The supernatant
was used for [Hb] determination. Twelve
samples, 11 of which were sampled by CT, had
to be excluded from [Hb] determination because
of blood clotting.