Effect of Isotonic and Hypotonic Fluid Therapy on Serum Sodium: A Randomized Controlled Trial

Abstract

There is little consensus about the type of maintenance fluid therapy and it’s the effect on serum sodium in adults. Thus, this study was conducted to assess the effect of maintenance fluid therapy on serum sodium of hospitalized patients in the intensive care unit. This randomized clinical trial was carried out on 64 patients aged 18-90 years hospitalized in the intensive care unit (ICU) of Imam Sadjad and Shahid Beheshti hospitals, Yasuj, Iran, in 2017. These patients were randomly allocated to take 2500-3000 milliliters of intravenous maintenance isotonic (0.9% saline) or hypotonic (0.45% saline) fluids daily. Blood and urine samples were taken to measure biochemical parameters before and 48 hours after the intervention. Data analyses were done by using SPSS 16 software via descriptive and analytic statistics. Twenty-eight patients in the 0.9% saline group (19 male and 9 female) and 32 patients in 0.45% saline (20 male and 12 female) completed the study. There was no significant difference between two groups in sodium (P=0.94), potassium (P=0.21), sugar (P=0.91), creatinine (P=0.21), Blood Urea Nitrogen (P=0.99), systolic (P=0.81) and diastolic (P=0.73) blood pressure, PH (P=0.27), bicarbonate (P=0.8), and urine specific gravity (P=0.73). Based on the results of this study, it was shown that the administration of maintenance hypotonic fluids has been appropriate for the patients and will not face them with the risk of hyponatremia.