Biological responses to exchange transfusion with liposome-encapsulated hemoglobin.
The present study evaluates the biological responses to 10% blood volume infusion ("top-loading," n = 7) or 50% blood volume exchange transfusion (n = 8) with a new preparation of liposome-encapsulated hemoglobin (LEH) in the conscious rat. Top-loading did not affect systemic hemodynamic variables but induced transient thrombocytopenia (-36% +/- 7%; P less than 0.05) and elevation of plasma thromboxane B2 (12.4 +/- 3.8 pg/100 microliters vs. undetectable levels at the control; P less than 0.05). Rats exchanged with LEH maintained mean arterial pressure (MAP) during the 3 hr observation period, whereas control (0.9% NaCl or lactated Ringer's solution) animals developed hypotension (-23 +/- 5 mm Hg, P less than 0.05). The maintenance of MAP in the LEH group resulted from the opposing effects of LEH-induced increase in total peripheral resistance index (TPRI; +0.06 +/- 0.01 mm Hg/ml/min/kg; P less than 0.05), and decreased cardiac index, (Cl, -25 +/- 6 ml/min/kg, P less than 0.05). In contrast, the decline in MAP in the control groups could be attributed to the lower Cl (-65 +/- 8 ml/min/kg; P less than 0.05). All rats developed metabolic acidosis (base excess of -9.7 +/- 0.6 mmol/liter; P less than 0.05), which was transient in the LEH group but progressive in the control groups. These data support the possible use of LEH as a blood substitute when massive transfusions are needed.
Rabinovici
R
R
Department of Surgery, Jefferson Medical College, Philadelphia, Pennsylvania 19107-5083.
Rudolph
A S
AS
Ligler
F S
FS
Smith
E F
EF
Feuerstein
G
G
D015121:6-Ketoprostaglandin F1 alpha / Q000032:analysis; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D001802:Blood Substitutes / Q000494:pharmacology*; D005078:Exchange Transfusion, Whole Blood; D006339:Heart Rate / Q000187:drug effects*; D006454:Hemoglobins / Q000008:administration & dosage* / Q000737:chemistry / Q000494:pharmacology; D007773:Lactates / Q000494:pharmacology; D019344:Lactic Acid; D008081:Liposomes; D008297:Male; D010713:Phosphatidylcholines; D051381:Rats; D011919:Rats, Inbred Strains; D012965:Sodium Chloride / Q000494:pharmacology; D013929:Thromboxane B2 / Q000032:analysis
D001802:Blood Substitutes; D006454:Hemoglobins; D007773:Lactates; D008081:Liposomes; D010713:Phosphatidylcholines; D019344:Lactic Acid; D012965:Sodium Chloride; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; C010942:1,2-distearoyllecithin