Systemic function, oxygenation and microvascular correlation during treatment of hemorrhagic shock with blood substitutes.
Systemic function and oxygenation changes during hemorrhagic shock treatment were continuously monitored and correlated with real-time microvascular changes. After splenectomy, each dog (n = 12) was hemorrhaged (MAP = approximately 50 mmHg; approximately 40% blood loss = 32-36 ml/kg) and randomly assigned to 4 resuscitation groups: autologous/shed blood, hemoglobin-based oxygen-carrier/Oxyglobin, crystalloid/saline, and colloid/Hespan. Systemic function and oxygenation changes were continuously monitored and measured using standard operating room protocols. Computer-assisted intravital microscopy was used to non-invasively videotape and objectively analyze and quantify real-time microvascular changes in the conjunctival microcirculation. All measurements were made during pre-hemorrhagic (baseline), post-hemorrhagic and post-resuscitation phases of the study. Pre-hemorrhagic microvascular changes were similar in all 12 dogs (venular diameter = 43 +/- 12 microm; red-cell velocity = 0.6 +/- 0.2 mm/s). All dogs showed similar significant (P<0.01) post-hemorrhagic microvascular changes: approximately 20% decrease in venular diameter; approximately 80% increase in red-cell velocity. These microvascular changes correlated with post-hemorrhagic systemic function and oxygenation changes. The resuscitations restored microvascular changes to pre-hemorrhagic values; the microvascular reversals also correlated with post-resuscitation systemic function changes in all groups. However, only shed blood resuscitation restored oxygenation level close to pre-hemorrhagic values. All 12 dogs survived resuscitation treatments despite differences in oxygen-carrying capability between groups.
Department of Pathology and Laboratory Medicine, UCD Medical Center, Sacramento, CA 95817, USA. atcheung@ucdavis.edu
Anthony T
AT
Cheung
Patricia L
PL
Duong
Bernd
B
Driessen
Peter C
PC
Chen
Jonathan S
JS
Jahr
Robert A
RA
Gunther
D000818:Animals; D001802:Blood Substitutes / Q000627:therapeutic use*; D001804:Blood Transfusion, Autologous; D004195:Disease Models, Animal; D004285:Dogs; D008833:Microcirculation / Q000187:drug effects* / Q000503:physiopathology; D018715:Microscopy, Video; D010100:Oxygen / Q000097:blood*; D012151:Resuscitation / Q000379:methods; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000628:therapy; D013156:Splenectomy
D001802:Blood Substitutes; D010100:Oxygen