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

摘要

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). Alldogs 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.