Resuscitation of bled dogs with pyridoxalated-polymerized hemoglobin solution.

We bled 25% of estimated total blood volume, then infused pyridoxalated polymerized human stroma-free hemoglobin solution (PP-SFH) (10 g/dl) to dogs under anesthesia in a volume equal to the blood removed. Central hemodynamics, blood flow distribution to organs, and renal function were studied up to 2-3 hours following the infusion. Mean arterial pressure was reduced from 120 +/- 3 to 86 +/- 7 mmHg at the end of the 30-minute hypovolumic period and the cardiac output was reduced by 27%. Immediately following the PP-SFH infusion we observed a further fall in blood pressure (43%) caused by a fall in cardiac output which lasted for 10 minutes. Blood pressure was restored gradually with the continuation of the infusion and the cardiac output was restored and maintained well. During the hypovolumic period, blood flow to the heart, renal cortex, and liver were reduced, whereas normal flow to the renal medulla and brain were maintained. After the resuscitation, blood flow to the heart, brain, liver, and renal medulla significantly exceeded the normal range, but remained subnormal in the renal cortex. Glomerular filtration rate (GFR), urine flow, and electrolyte excretion were all reduced during the hypovolumic period and were not restored to the pre-bleed levels after the infusion.