RESUMO
Ten male patients with bilharzial hepatosplenomegaly were the subject of this study. Another ten male patients of nearly the same age and body weight were taken as control. The plasma and blood volumes were estimated before and 30 minutes after 2% halothane anaesthesia without any surgical interference. The plasma volume was determined by Evens blue dye method and the total blood volume was calculated from the haematocrit value. There was no significant difference between the mean blood volumes of the two groups before the administration of halothane. The 2% halothane administration for 30 minutes, significantly increased the mean total blood volumes in both groups, although the difference between the mean percent increases was not significant. The mean haematocit values of both groups did not display any significant change before or following the exposure to halothane. Patients with bilharzial hepatosplenomegaly developed more hypervolaemia during halothane anaesthesia, possibly mainly due to an increase in the plasma volume. The effect of halothane anaesthesia on the blood volume was the subject of conflicting reports. Some authors [Payne and colleagues, 1959, and Grable and associates, 1962] reported an increase in blood volume, while other [Morse and colleagues, 1963] could not detect any change in blood volume following the administration of halothane. Hepatosplenic bilharziasis is a disease associated with changes in haemodynamic pattern [Mousa, 1967] and these changes can be modified by the action of various drugs especially the vasoactive ones. The purpose of this study is to report the effect of halothane anaesthesia on the plasma and blood volumes in hepatosplenic bilharziasis