SOME EFFECTS OF PECTIN SOLUTIONS DURING POSTHEMORRHAGIC HYPOTENSION

Abstract

A 1.5% buffered pectin soln. exerting an oncotic pressure of 67 to 68.7 cm. of water was injected at a rate of 3-5 ml./min. after varying periods of post-hemorrhagic hypotension (50 mm. Hg). The usefulness of such solns. is apparently limited to the early periods of such hypotension. Given after 30 mins., 11 of 19 dogs showed a satisfactory hemodynamic response for 4-6 hrs. after adm. Pectin infusions, given after a post-hemorrhagic dilution of blood has already occurred, cause a further dilution by virtue of the fluid injected and this is rather well maintained for 4-6 hrs. Evidence that additional dilution results from osmotic attraction of water from tissues was not found. No correlation existed between maintenance of hemodilution and favorable hemodynamic reactions; on the contrary, the animals that recovered usually showed some tendency to reconcentration. This suggests that the demonstrated ability of a colloid a, to maintain an effective oncotic pressure over a considerable time interval, and b, to increase blood volume in normal animals is not a satisfactory criterion of its physiological usefulness. While no evidence was obtained experimentally or at necropsy that the rapid sedimentation and agglutination produced by .such solns. is harmful, the occurrence of a precipitate failure of the circulation in too many expts. and the inability to overcome this by subsequent large infusions of blood suggest that pectin infusions may exert some deleterious influence when used after severe hemorrhage. Consequently, caution should be exercised in the employment of pectin solns. in such conditions.