PurposeThe aim of this study was to determine the effect of spray use on mouth dryness and thirst of patients undergoing major abdominal surgery during the postoperative period DesignThis research was conducted as a randomized controlled trial. MethodsOne hundred thirty patients undergoing abdominal surgery were assessed for eligibility; the sample consisted of N = 104. Subjects were randomized into one of three groups. Subjects in the control group were administered a small amount of water at room temperature using a syringe (clinic routine application, approximately 1-2 mL). Subjects in the second group were administered cold water spray orally (0.4 mL per application). Subjects in the third group were administered cold saline (0.9% NaCl) spray orally (0.4 mL per application). Applications were performed twice every hour. Subjects’ postoperative thirst severity, mouth dryness severity, oral health condition, and pH values of saliva were evaluated after 8, 20, 24, 36 and 40 hours. Subject satisfaction was evaluated at the end of the second postoperative day. FindingsIn our study, no significant difference was found between the three groups in terms of age, gender, American Society of Anesthesiologists grade (ASA), preoperative thirst and mouth dryness, and preoperative oral health condition (P > .05). A significant difference was found between the groups in terms of subjects’ thirst and mouth dryness severity scores after 8, 20, 24, 36, and 40 hours (P < .05). The intervention group that received cold water spray demonstrated statistically significant differences when compared to the control and saline moistening groups. No significant difference was found between subjects’ oral health condition and pH scores after 4, 8, 20, 24, 36, and 40 hours (P > .05). ConclusionsThe results of our study show that cold water spray was more effective on the thirst and mouth dryness scores of subjects undergoing major abdominal surgery compared to cold normal saline spray and water applied using a syringe, although it was not an effective factor on oral health condition and pH values of saliva.