Acute limited normovolemic hemodilution can be safely used in a malnourished model
Woloszyn, T.T.; Coons, M.S.; Rodriguez, C.; Levy, R.; Heaney, M.; Wang, S.; Marini, C.P.
American Surgeon 58(1): 22-27
1992
ISSN/ISBN: 0003-1348 PMID: 1739225 Document Number: 387965
This study investigates the effects of acute limited normovolemic hemodilution (ALNH) on intestinal healing in a malnourished animal model. Twenty rabbits were randomized into three Groups: Group 1 = control; Group 2 = ALNH (removal 35% blood volume and maintenance of normovolemia with 3:1 crystalloid infusion) followed by retransfusion (RT) after small bowel anastomosis (ANA). Group 3 had a restructed diet for 3 weeks preoperatively to cause a 15 per cent to 20 per cent weight loss. A six cm segment of small bowel (SB) was resected and anastomosed (ANA) in all animals. Blood pressure (BP), transserosal oxygen tension (TsPao2), hematocrit (Hct), colloid oncotic pressure (COP), wet-to-dry weight ratio (WW/DW), hydroxyproline (OH-Pro) content, and tensile strength (TS) of the ANA and a segment of adjacent SB were determined. BP did not change from baseline (BL) in Group 2 during ALNH; however, it rose significantly after RT (P < 0.05). BP decreased significantly during ALNH in Group 3 (P < 0.05) and did not rise above baseline after RT. There was no significant change in TsPao2 from BL within groups during the experiment. The Hct and COP decreased significantly after ALNH in Group 2 and 3 after ALNH compared to BL (P < 0.05). After RT the Hct and COP increased and by Day 8 the Hct had rise to BL values in Group 3 but not in Group 2 (P < 0.05), whereas COP values were not significantly different from BL in either group. There was no differences in WW/DW or TS between or among the three groups. OH-Pro content of the ANA segment in Group 1 was 1 per cent lower on Day 8 than normal SB on Day O; in contrast, OH-Pro content was reduced more than 70 per cent in Groups 2 and 3. Fluid requirements were higher in Groups 2 and 3 compared to Group 1 (P < 0.05). Based on the results of this study, the authors conclude that ALNH can be safely used in a malnourished model; however, because of blood volume contraction in malnourished patients, blood volume removal should be limited to less than 30 per cent of estimated blood volume.