Thermal Stability of 0.9% Sodium Chloride IV Fluid exposed to Short- and Long-Term Extreme Conditions

Abstract

Purpose: 0.9% sodium chloride IV fluid (normal saline) is critical in a clinical setting and may save lives. Data on thermal stability of normal saline, in out-of-hospital settings, are lacking. The purpose of this study was to evaluate the effect of temperature on normal saline stability. Method: Normal saline provided in flexible plastic containers (Qatar Pharma, BA:1929013008, n=96) were stored at constant temperature of 22, 50, or 70iC, and at cyclic temperature of 70iC for 8 hours and 22iC for 16 hours for a period up to 28 days. The containers were sampled at 0, 12, 24, 48 and 72 hours and at 1, 2, 3, and 4 weeks in the short- and long-term study, respectively. Fluid inside containers was evaluated for discoloration, turbidity, bulging, and pH. A 1 mL of normal saline was withdrawn from each container and stored at 4iC until analysis. A 20 mL was diluted in 12 mL distilled water to be injected into ion exchange chromatography instrument (Metrohm, 850 Professional IEC) for the measurement of sodium and chloride levels. Results: Discoloration or turbidity of normal saline fluid was not observed at any temperature or exposure period. The container slightly bulged at 50C and largely bulged at 70 C & cyclic. The pH was 5.59+-0.08 at 22C, 5.73+-0.04 at 50C, 5.86+-0.02 at 70C and 5.79+-0.03 at cyclic. Remaining sodium and chloride levels ranged from 100.2+-0.26% to 111.27+-4.22% and from 99.04+-0.76 to 110.95+-2.62%, respectively. Conclusion: Normal saline containers are stable up to 4 weeks under simulated constant and cyclic high temperatures. Storage in the cabinet of ambulance vehicles during hot summer season in an arid country like Qatar is to be assessed in real-life conditions.