Systemic function, oxygenation and microvascular correlation during treatment of hemorrhagic shock with blood substitutes

• Published in: Clinical hemorheology and microcirculation Vol. 34; no. 1-2; pp. 325 - 334
• Main Authors: Cheung, Anthony T, Duong, Patricia L, Driessen, Bernd, Chen, Peter C, Jahr, Jonathan S, Gunther, Robert A
• Format: Journal Article
• Language: English
• Published: Netherlands 2006
• Subjects: Animals; Blood Substitutes - therapeutic use; Blood Transfusion, Autologous; Disease Models, Animal; Dogs; Microcirculation - drug effects; Microcirculation - physiopathology; Microscopy, Video; Oxygen - blood; Resuscitation - methods; Shock, Hemorrhagic - drug therapy; Shock, Hemorrhagic - therapy; Splenectomy
• ISSN: 1386-0291

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.