HS reduces the volume of intravenous fluid required to maintain patients undergoing surgery but transiently increases serum sodium. It is not known if HS effects patient survival and morbidity but it should be tested in randomized clinical trials that are designed and powered to test these outcomes.
Effect of hypertonic saline infusion on postoperative cellular immune function: a randomized controlled clinical trial.
Previous studies found hypertonicity to affect immune responses in intact laboratory animals and in human blood cell cultures. In this study, the authors investigated the cellular immune response to surgery after preoperative infusion of hypertonic saline in humans.
                Sixty-two women scheduled to undergo abdominal hysterectomy were randomly assigned to single-blinded infusion of 4 ml/kg NaCl, 7.5%; 4 ml/kg NaCl, 0.9%; or 32 ml/kg NaCl, 0.9%, over 20 min. Blood was collected at baseline, during surgery, and 1, 24, and 48 h after surgery for the determination of leukocyte and differential counts, flow cytometric phenotyping of mononuclear cells, and natural killer cell activity against K 562 tumor cells. Phytohemagglutinin-induced lymphocyte proliferation, plasma elastase, and neutrophil chemotaxis were measured at the same time points except during surgery. The authors tested cell-mediated immune function in vivo by delayed-type hypersensitivity reaction in the skin.
                Surgery induced well-known changes in the cellular immune response, which were unrelated to the tonicity or volume of the infused fluids.
                Infusion of a clinically relevant dose of hypertonic saline did not seem to modify the postoperative cellular immune response after elective abdominal hysterectomy.