HEMODYNAMIC, PLASMA-VOLUME, AND PRENODAL SKIN LYMPH RESPONSES TO VARIED RESUSCITATION REGIMENS

The theoretical efficacy of hypertonic saline (HS) resuscitation for h emorrhagic shock purportedly stems from the osmolar extraction of intr acellular fluid into the plasma, This hypothesis presumes a concomitan t expansion of the interstitial fluid space, Colloid resuscitation, in theory, expands the plasma volume by extracting interstitial fluid, T hese hypotheses were tested in a canine-modified Wigger's model of hem orrhagic shock, Forty, male, splenectomized dogs were anesthetized and instrumented, Animals underwent a baseline equilibration period follo wed by shock for 120 minutes, Each animal was randomized to one of fou r groups and received equal amounts of Na+ either as lactated Ringer's (LR) solution, 10% dextran 40 (Dex) in normal saline, 7.5% saline (HS ), or 7.5% saline plus Dex (HSD), Parameters measured at baseline, sho ck, and at postresuscitation 30 minutes, 60 minutes, 90 minutes, and 1 20 minutes, included: mean pressure (MAP), output, pulmonary capillary wedge pressure, prenodal skin lymph flow, serum and lymph albumin, we t-to-dry skin ratios, and plasma volume, MAP, cardiac output, and plas ma volume were most quickly restored with LR and Dex resuscitation (MA P = 106 and 118 mm 118) compared to HS and HSD (MAP = 98 and 92 mm Hg) , Lymph now and lymph albumin flux were best restored with LR and HSD (mean = 85 and 48 mu L/min) compared to Dex and HS (mean 36 and 37 mu L/min). Wet/dry skin ratios were greatest at 60 minutes in the LR grou p but similar at 120 minutes in all four groups, These data suggest th at interstitial fluid space remains contracted during the first hour a fter 118, HSD, and Dex resuscitation compared with LR resuscitation, e ven though the restoration of plasma volume, MAP, and cardiac output i s greatest with the Dex regimen, Further studies with total body water and intracellular water are needed in this model.