Electrolyte-based calculation of fluid shifts after infusing 0.9% saline in severe hyperglycemia

Abstract

Background Early treatment of severe hyperglycemia involves large shifts of body fluids that entail a risk of hemodynamic instability. We studied the feasibility of applying a new electrolyte equation that estimates the degree of volume depletion and the distribution of infused 0.9% saline in this setting. Methods The new equation was applied to plasma and urinary concentrations of sodium and chloride measured before and 30 min after a 30-min infusion of 1 L of 0.9% saline on two consecutive days in 14 patients with severe hyperglycemia (mean age 50 years). The extracellular fluid (ECF) volume was also estimated based on the volume dilution kinetics of chloride. Results On day 1, the baseline ECF volume amounted to 11.5 L. The saline infusion expanded the ECF space by 160 mL and the intracellular fluid space by 375 mL. On day 2, the ECF volume was 15.5 L, and twice as much of the infused fluid remained in the ECF space. The chloride dilution kinetics yielded baseline ECF volumes of 11.6 and 15.2 L on day 1 and day 2, respectively. No net uptake of glucose to the cells occurred during the two 1-h measurement periods despite insulin administration in the intervening time period. Conclusions The electrolyte equation was feasible to apply in a group of hyperglycemic patients. The ECF space was 3 L smaller than expected on admission but normal on the second day. Almost half of the infused fluid was distributed intracellularly.

Role of Fluid and Sodium Retention in Experimental Ventilator-Induced Lung Injury

“…To investigate the sodium distribution between intracellular/extracellular compartments and the non-osmotic sodium storage, the following assumptions were made: (1) extracellular and intracellular compartments equal 20 and 40% of the pig body weight ( Svensson et al, 2020 ); (2) the osmotic concentration between the two compartments is equal and the equilibrium is maintained by means of water shifts; (3) the count of milliosmoles in the extracellular fluid at the end of any timepoint must be equal to the initial amount of milliosmoles plus the milliosmoles due to the retained sodium (Na + ret × 2); (4) the milliosmoles exceeding this equilibrium were classified as missing sodium (Na + miss ), i.e., sodium stored in a non-osmotic form.…”

“…To investigate the sodium distribution between intracellular/extracellular compartments and the non-osmotic sodium storage, the following assumptions were made: (1) extracellular and intracellular compartments equal 20 and 40% of the pig body weight (Svensson et al, 2020); (2) the osmotic concentration between the two compartments is equal and the equilibrium is maintained by means of water shifts;…”