Serum [Na] < baseline value, or SNa rising too slowly

Sort out the cause: input vs output

1. Input:

   • Adequate fluid restriction?
   • Fluid coming from IV drugs / infusion
   • HTS infusion rate too low e.g. under-estimation of BW
     • → treat cause as identified

2. Output:

   • High urine cation (Na & K) concentration
     • Esp if urine cation [Na+K] > serum [Na]
     • ?possibility of untreated Addisonian or hypothyroid
       • → ↑HTS rate
         1. Use MD Calc’s calculated infusion rate for 0.5mmol/L/h correction
            • ↑blood/urine monitoring to Q3H
              • (more frequent than Q3H may not be useful due to laboratory turnaround time)
            • Overshooting should not be huge
              • ↓rate as appropriate if rate of rise too fast
              • → can restart titration protocol when Na starts rising
     • In the case of desalination / renal salt losing → need to compensate with additional HTS
       • Read the relevant FAQ post
       • → go to this link: In the case of desalination from renal salt loss