Resuscitation following severe, controlled hemorrhage associated with a 24 h delay to surgical intervention in swine using a hemoglobin based oxygen carrier as an oxygen bridge to definitive care.
OBJECTIVE
To test our hypothesis that the hemoglobin based oxygen carrier HBOC-201 would have similar or superior efficacy to 6% hetastarch (HEX) as a pre-hospital 'bridging' fluid for hemorrhagic shock when delay to definitive medical care is prolonged to 24h.


METHODS
Twenty-four pigs were anesthetized, instrumented, given a soft tissue injury, and bled 55% estimated blood volume. Pigs were randomized to receive HBOC-201, HEX, or no resuscitation fluids (NON). At 4h post-injury, surgical sites were repaired and pigs were recovered from anesthesia. Animals were non-invasively monitored, administered blood for anemia or saline for hypotension at 24 and 48h, and monitored for 72h.


RESULTS
Survival to 72h was 87.5% (7/8) in HBOC-201 and HEX pigs compared to 25% (2/8) in NON pigs (p=0.01). Increased mean arterial pressure was observed in the HBOC-201 group (p<0.0001). Cardiac index was highest in HEX pigs (overall p<0.001, HBOC-201 versus HEX p=0.002). Transcutaneous tissue oxygenation was higher with HBOC-201 (overall p=0.04, HBOC-201 versus HEX p<0.01). HBOC-201 and HEX pigs had comparable heart rates, pulmonary pressures, pre-hospital fluid requirements, venous O(2) saturation, base deficit, and lactic acid. Hemoglobin was decreased with HEX (overall p<0.0001, HBOC-201 versus HEX p<0.0002). At 24h, 14.3% (1/7) HBOC-201 pigs required blood transfusions versus 100% HEX (7/7) and NON (2/2) pigs (p>0.001).


CONCLUSIONS
HBOC-201 restored hemodynamics, maintained tissue oxygenation, and decreased blood transfusions in comparison to HEX in severe controlled HS with 24h delay to simulated hospital care. These results support the potential use of HBOC-201 as a bridging resuscitation fluid for HS.
Philbin
Nora
N
Naval Medical Research Center, Silver Spring, MD 20910, USA.
Handrigan
Michael
M
Rice
Jennifer
J
McNickle
Kyle
K
McGwin
Gerald
G
Williams
Rita
R
Warndorf
Mathew
M
Arnaud
Françoise
F
Malkevich
Nina
N
McCarron
Richard
R
Freilich
Daniel
D
D000704:Analysis of Variance; D000818:Animals; D001802:Blood Substitutes / Q000494:pharmacology*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D016009:Chi-Square Distribution; D004195:Disease Models, Animal; D006454:Hemoglobins / Q000494:pharmacology*; D016016:Proportional Hazards Models; D011897:Random Allocation; D012771:Shock, Hemorrhagic / Q000188:drug therapy* / Q000503:physiopathology / Q000601:surgery; D013552:Swine; D013556:Swine, Miniature; D013997:Time Factors
D001802:Blood Substitutes; D006454:Hemoglobins; C096798:HBOC 201