Abstract
Background and Aims
Crystalline solutions, such as normal saline 0.9% (N/S 0.9%) and Ringer's Lactate (L/R), are readily administered for increasing plasma volume. Despite the utility of administering N/S 0.9% to hypovolemic patients, the dose of 154 mmol of sodium (Na) contained in 1 L exceeds the recommended daily dose increasing the risk of sodium overload and hyperchloremic metabolic acidosis. In contrast, L/R solution has the advantage of lower Na content, significantly less chlorine and contains lactates which may be advantageous in patients with significant acidemia such as patients with acute kidney injury (AKI) and chronic kidney disease (CKD). The aim of the present study is to investigate the safety and efficacy of administration of L/R versus N/S 0.9% in patients with prerenal AKI and established CKD.
Method
The study included adult patients with known CKD stage II to V without need for dialysis, with prerenal AKI (AKIN Stage I to III Criteria). Patients with other forms of AKI as well as hypervolemia, heart congestion or hyperkalemia (serum K>5.5 meq/l) were excluded from the study. Patients were randomized in 1:1 ratio to receive intravenously either N/S 0.9% or L/R solution at a dose of 20 ml/kg body weight/day. We studied kidney function (eGFR: CKD-EPI) and response to treatment at discharge and at 30 days after discharge, duration of hospitalization, improvement in serum bicarbonate levels (HCO3), acid-base balance, serum potassium levels and the need for dialysis.
Results
The study included 26 patients (17 males) with a mean age of 59.1 ± 16.1 years. Thirteen patients received treatment with N/S 0.9% and the rest with L/R solution. Baseline demographic and clinical characteristics at hospital admission and historical data did not show any significant differences in both groups of patients. Renal function at the onset of AKI did not show significant differences between the two groups (16.4 ± 5.8 vs 16.9 ± 5.7 ml/min/1.73 m2, p=ns, treatment with N/S and L/R respectively). The mean volume of solutions received by the two groups (N/S 0.9% 1119 ± 374 vs L/R 1338 ± 364 ml/day, p=ns) as well as the mean total volume of liquids received per day, did not differ significantly (2888 ± 821 vs 3069 ± 728 ml/d, p=ns). Patients treated with L/R were discharged 1 day earlier than patients treated with N/S (5.2 ± 3.2 vs 6.2 ± 4.9 days of hospitalization, p=ns). Renal function improvement during hospitalization and 30 days after discharge did not differ significantly between the two groups. Patients that received L/R showed a higher increase in plasma HCO3 (ΔHCO3) concentration at discharge than those that received N/S 0.9% (4.9 ± 4.1 vs 2.46 ± 3.7 meq/l, p=ns) and pH increase (ΔpH) was slightly higher in those that received L/R solution (0.052 ± 0.066 vs 0.023 ± 0.071, p=ns). Patients treated with N/S 0.9% showed a greater decrease in serum potassium (ΔK) at discharge compared to those treated with L/R (-0.39 ± 1.03 vs -0.17 ± 0.43 meq/l, p=ns, respectively). No patient received acute dialysis treatment.
Conclusion
Administration of L/R solution as a hydration treatment to patients with prerenal AKI and established CKD is not inferior concerning safety and efficacy to N/S 0.9% solution. In addition, L/R administration seems to marginally improve acid-base balance in this specific group of patients.
Compensation of progressive hypercapnia in the toad (Bufo marinus) and the bullfrog (Rana catesbeiana)
