PLASMA SUBSTITUTES 



71 



wheezing, abdominal pain, cramps, vasomotor rhini- 

 tis, and swelhng of the joints or extremities, or ortho- 

 static hypotension. Reactions were seen in 51.5% of 

 the group receiving Swedish dextran and in 8.2 % of 

 those receiving American dextran. The reactions 

 were less frequent in patients who were given spinal 

 anesthesia. 



PHYSIOLOGICAL EFFECTS OF COLLOIDAL INFUSIONS 

 IN NORM.-VL M.'VN AND IN ANIMALS 



Plasma Volume 



If plasma substitutes are to be effective they must 

 function as effective expanders of plasma volume. 

 Jenkins and associates (63) gave 38 convalescent pa- 

 tients 1000 ml of PVP (3.5*^ P\'P Macrose, Schenley) 

 intravenously o\er a 2-hour period. The average fall 

 of hematocrit was 5.5 volume %. After 24 hours the 

 hematocrit was within normal range except in 7 pa- 

 tients in whom hemodilution lasted 24 hours or longer. 

 Plasma volumes, measured by T-1824 dye, showed in 

 2 hours expansion of plasma volume a\eraging 50% 

 of the infused volume. Using thiocyanate to measure 

 total available fluid (extracellular fluid) i liter of 

 PVP was followed by an average increase in extra- 

 cellular fluid of 2350 ml exclusive of the plasma vol- 

 ume change. Jackson & Frayser (58) gave dogs i g of 

 acacia per kg intravenously daily for 20 days. A sharp 

 increase in plasma volume occurred. The hematocrit 

 and hemoglobin fell strikingly. Handford and asso- 

 ciates (45), using 4':c glycerol pectate, ga\e an amount 

 equivalent to 5% of body weight to normal dogs and 

 produced effective plasma volume expansion that 

 persisted for 12 hours. Barker and associates (7) bled 

 nine normal humans 1000 ml of blood and ga\e 1000 

 ml of a plasma expander over a 30-min period. Four 

 received oxypolygelatin, three isotonic saline, and two 

 plasma. The oxypolygelatin was 5 "^ in isotonic 

 saline (Baxter). The plasma volume was well main 

 tained by plasma or oxypolygelatin, but not by saline. 

 The blood volume after saline decreased to 88 % of 

 the post-infusion volume in 15 min. 



Wasserman & Mayerson (107) studied Expandex 

 6 % dextran, average molecular weight 60,000 with a 

 range of 25,000 to 200,000. Also these workers used 

 two other dextrans, one small enough to get into the 

 urine (mol wt range 5,900 to 10,400) and the other 

 too large to appear (90,000 to 155,000 mol wt). The 

 plasma volume was expanded to a greater degree by 

 the suprarenal fraction in both bled and unbled dogs. 



The percentage remaining in the circulation was 

 greatest with the suprarenal threshold fraction. Only 

 2 % of the dose of the large molecular dextran was in 

 the urine in 4 hours, but with clinical dextran, average 

 60,000 molecular weight, 35% was in the urine in 4 

 hours in bled dogs and 50% in unbled dogs. Forty 

 ml per kg body weight infusions of dextran increased 

 lymph flow. Wasserman & Mayerson ( 1 08) gave 6 % 

 clinical dextran infusions into dogs. Dextran was 

 found to be a more effective plasma expander than 

 plasma itself when plasma volumes were measured by 

 I"' human serum albumin. Dogs bled to a blood pres- 

 sure of 40 mm Hg showed an expansion of plasma vol- 

 ume equivalent to 80 % of the infusion volume 4 hours 

 after the end of the infusion. In unbled dogs, the 

 plasma volume was expanded only 25% of infusion 

 volume at this time. Dextran levels in thoracic duct 

 lymph remained below plasma dextran levels. The 

 dextran plasma-lymph concentration gradient re- 

 mained for at least 24 hours and was higher than that 

 for albumin and globulin. It is suggested that dextran 

 leaks into interstitial fluid more slowly than plasma 

 protein and is therefore a good plasma expander. 



Metcalf & Rousselot (74) gave 500 ml of 6% dex- 

 tran in saline to 12 convalescents. The plasma volume 

 increment after 6 hours was from 238 to 610 ml. 

 Meyer and associates (75) gave six normal humans 

 500 ml of 6 % dextran in normal saline. Using P^^ 

 tagged red cells, they found the increase of blood vol- 

 ume to be between 960 to 2850 ml. The maximum 

 increase was between 15 min and 6 hours and 15 min 

 after the completion of the infusion. Bowman (17), 

 using Plavolex 6 % dextran in isotonic sodium 

 chloride, found 20-hour increases of blood volume to 

 be greater with dextran than with gelatin, serum al- 

 bumin, or plasma. 



Bloom & Wilcox (14) described a metliod for 

 measuring dextran in the blood and the urine. The 

 method is not specific in that it will measure any 

 polysaccharide resistant to digestion with hot alkali, 

 precipitable by ethanol, and yielding a color similar 

 to that of glucose with the anthrone reagent. How- 

 ever, substances meeting these requirements are not 

 ordinarily found in blood and urine. 



Hemoslasis 



One of the more important side effects of the in- 

 fusion of plasma volume expanders, particularly 

 dextran, is their impairment of hemostasis. Davidsohn 

 & Stern (25) gave to rabbits weighing 2500 to 3500 g 

 intravenous or subcutaneous injections of 3.5% PVP. 



