Glomerulotubular sodium dynamics after supplemental albumin resuscitation
Lucas, C.E.; Ledgerwood, A.M.; Higgins, R.F.
American Surgeon 47(5): 204-207
1981
ISSN/ISBN: 0003-1348 PMID: 7235383 Document Number: 177762
Previous studies showed that albumin, when added randomly to a standard resuscitation regimen for hypovolemic shock, causes renal Na retention; the mechanism was not delineated. Intrarenal Na dynamics were analyzed in 69 patients who received an average of 14.3 transfusions for shock; 34 patients received supplemental albumin averaging 27 g during operation and 150 g/day for 3 to 5 days. Renal plasma flow (ERPF), glomerular filtration rate (GRF), Na and K perfusion and filtration, distal nephron Na delivery, distal nephron reabsorption of Na and K, and clearance of Na and K were studied serially and compared by Student t test. Albumin increased serum albumin levels (4.3 vs. 2.8 g/dl), plasma volume (3841 vs. 3544 ml), ERPF (469 vs. 431 ml/min) and renal perfusion of Na (64 vs. 56 meq/min). GFR fell (87 vs. 105 ml/min), thereby reducing Na filtration (11.8 vs. 14.5 meq/min) and distal nephron Na delivery (1.7 vs. 2.18 meq/min). Albumin increased the percent of distal nephron Na reabsorption (87% vs. 78%), causing a fall in Na clearance (1.6 vs. 2.3 ml/min). These changes reflect increased oncotic pressure in the glomerular tuft, peritubular vessels, and inner medullary interstitium; they are partially mediated through distal nephron Na-K exchange. The clinical consequences include central volume overload with cardiopulmonary failure.