Participants’ treatment regimen

The hydration solutions were prepared by the hospital chemotherapy pharmacist in the chemotherapy mixing unit. Each electrolyte for supplementation was diluted in a separate liter of normal saline; as follows: Potassium chloride (KCl) (1.5 g), Magnesium sulfate (1 g) and calcium gluconate (1 g) and were each separately diluted in 1 L normal saline and added up to 3 L.

The control group received 3 L normal saline while the treatment group received 3 L of normal saline in which the triple electrolyte supplementation was diluted. The solutions were prepared on the day of administration and the pharmacist ensured proper mixing by slowly shaking the bottle for approximately 10 times. The hydration fluid was administered for 6 h after which chemotherapy was given. The patient-specific cisplatin-based chemotherapy regimens varied from patient to patient as prescribed by the medical oncologist. Some patients received only cisplatin while others were prescribed a cisplatin-based regimen that contained two or three other cytotoxic drugs. The cisplatin injections were prepared as per the manufacturer’s instructions and administered as per prescription. The dose was diluted in 1 L of normal saline 30 min after hydration and administered by IV infusion over 90 min. All participants received a cisplatin dose ≥50 mg per week. Other medications given to participants included Granisetron 1 mg/ml injection, Dexamethasone 4 mg/ml injection, Ondansetron 8 mg tablet, and Dexamethasone 4 mg tablets. Besides hydration, participants were encouraged to drink a minimum of 500 ml of water daily, following the administration of cisplatin.

Data entry, cleaning, and analysis were done using Statistical Package for Social Science (SPSS) version 23.0. Continuous variables were expressed using measures of central tendency while categorical data such as serum creatinine values were expressed as log mean, frequencies, or proportions. A t-test was used to compare the mean Serum creatinine between the 2 groups from baseline to day 28. Z-test was used to compare the proportion of patients who had serum creatinine elevation 1.5 times baseline between the 2 groups. Univariate analysis was done using chi-square to determine the association between the different factors and AKI. Factors with p-values less than 0.2 in bivariate analysis were entered into a logistic regression to determine the association between nephrotoxicity and known associated factors noted on univariate analysis. Survival analysis was performed using Kaplan Meier to determine differences in time to an event using the log-rank test. A P-value of < 0.05 was considered statistically significant.