Outpatient use of oral rehydration solutions in apache population: Effect of instructions on preparation and contamination

Oral Rehydration Solutions (ORS) containing 90 and 50 mmol/L sodium have recently been recommended for use in ambulatory children in the U.S. These solutions are now marketed in powder form by some commercial companies. However, few data are available in the U.S. on the accuracy with which the solutions are mixed at home or on the bacterial contamination that may occur during mixing. We evaluated the effect of various forms of instructions on the occurrence of bacterial contamination and accuracy of mixing ORS at home by mothers of patients who were dispensed the dry ingredients of an ORS containing 90 mmol/L sodium at the U.S. Public Health Service Hospital, Whiteriver, Arizona. Patients were randomized to one of the four following groups: group I (23 patients) was given written instructions for mixing the solution along with a pre-marked container; group II (22 patients) was given written instructions only; group III (22 patients) was given a premarked container only; and group IV (19 patients) was given neither. All patients were given oral instructions in the preparation of ORS and were asked to refrigerate the reconstituted ORS. We collected samples of ORS at the patient's home 1 day after the clinic visit, to measure their electrolyte content and to identify any bacterial contamination. Mean Na⁺ concentrations were significantly lower in the ORS prepared by mothers/guardians in groups that were not given a premarked container [82 ± 13 (II) and 79 ± 21 (IV) mmol/L vs. 88 ± 13 (I) and 92 ± 14 (III) mmol/L; p < 0.01]. The frequency of refrigeration was as follows: 89, 75, 74, and 53% for groups I-IV, respectively (p = 0.15). The frequency of refrigerated samples with bacterial counts below the threshold of detection in each group was 63% (I), 33% (II), 21% (III), and 12% (IV) (p = 0.043). We conclude that when the dry ingredients of ORS are dispensed to ambulatory patients, they should be given a premarked container as well as detailed written and oral instructions.