Increased blood sodium concentration and blood osmotic pressure during treatment with 3% NaCl solution Table 3.32.Complications during treatment withNaCl 3% Complications Number of patients (n=83) Percentage (%) Hypertonic 2 2, 4% Hypernatremia 2 2, 4% Comment: 2/83 patients (2, 4%) had hypernatremia, 2 patients had blood hypertonic during treatment of NaCl 3% infusion.