The purpose of this study is to determine the effects of spray use on dry mouth and thirst of patients who had undergone major abdominal surgery. The methods used to alleviate the thirst and dry mouth experienced by patients undergoing major abdominal surgery are limited. This research was conducted as a randomized controlled trial.

The study sample includes patients who had undergone major abdominal surgery induced by upper or lower gastrointestinal system malignancies. The patients who met the inclusion criteria were informed about the purpose of the study and were invited to the study. Those who accepted to participate in the study were included in the study.

Patients who had undergone major abdominal surgery with general anesthesia (induced by upper or lower gastrointestinal system malignancies), who do not have any oral and nasal diseases, who do not have visual, hearing, speech and understanding problems, who were in the American Society of Anesthesiologists (ASA) I and II grades, who were aged 18 or over and agreed to participate in the study were included.

Patients whose mouth and tongue mucosa integrity was degraded, who had a cognitive disorder, or were suffering from neurological, renal, cardiac or pulmonary disorders that could affect the test results, or who use psychoactive drugs were excluded.

The standard anesthesia protocol was implemented to all patients suitable for the study. In the postoperative period, the standard rational dose antibiotic therapy (1st generation cephalosporin + metronidazole), metoclopramide HCL, NSAIDs, LMWH, N-acetylcysteine (NAC), H2-receptor blockers (ranitidine HCL), pethidine HCL 50 mg/ml, when required, and maintenance fluid therapy (Combination of normal saline, lactated Ringer's and Dextrose) by their weight were administered to the patients.

First Control Group: No intervention was performed on the patients in the control group. To prevent ethical violations, patients received routine clinical practice (a small amount of water was administered orally, using a syringe).

Second Intervention Group: Cold water kept at +40 C in the refrigerator was added into 50cc spray-head bottles and administered to patients orally in the postoperative phase, by spraying twice hourly.

Third intervention Group: Cold normal saline (0.9% NaCl) kept at +40 C in the refrigerator was added into 50cc spray-head bottles and administered to patients orally in the postoperative phase, by spraying twice hourly.

No intervention was performed on patients from midnight thru 06:00 AM, in order not to disturb the circadian rhythms of all patients.

Considering surgery end time and circadian rhythms of patients, the data of the patients were recorded at the post-operative 4, 8, 20, 24, 36, 40th hours. The flow chart of the study is shown in Figure 1. In the cold water and cold normal saline applications, 50cc glass bottles, plastic spray head, and cover were used. New material was used for each patient.

Preoperative measurements: Patients' data such as age, gender, comorbid diseases, ASA (American Society of Anesthesiologists) grade, diagnosis, preoperative thirst intensity, preoperative mouth dryness intensity, preoperative oral health condition were recorded.

Outcome measurements Postoperative evaluations were made after the interventions. Intensity of Thirst: VAS with a range of 0-10 points (0: mild, 10 very severe) was used while the thirsty severity of all patients were evaluated.

Intensity of Mouth Dryness: VAS with a range of 0-10 points (0: never experiencing mouth dryness, 10: experiencing very intense mouth dryness) was used while the mouth dryness severity of all patients were evaluated.

Oral Health Condition: To assess patients' oral health condition, the Oral Health Assessment Tool (OHAT) was used. The first four items of the scale that assess lips, tongue, gums and tissue, and saliva were used. The lowest score to be obtained from the scale is 0, while the highest score is 8 (0=healthy; 1=changes; 2=unhealthy). A higher OHAT score indicates a poor oral condition.

Saliva PH: To measure the PH of saliva, the patient's saliva sample in a sterile container was assessed using PH test strips.

Patient Satisfaction: To evaluate patient satisfaction, overall satisfaction was scored using a 10-point numerical rating scale (NRS) from 0 (complete dissatisfaction) to 10 (complete satisfaction).

At the postoperative 4th hour, the severity of thirst and dry mouth, oral health status and saliva PH values were evaluated in terms of differences between the groups.

At the postoperative 8th hour, the severity of thirst and dry mouth, oral health status and saliva PH values were evaluated in terms of differences between the groups.

At the postoperative 20,24,36 and 40th hour, the severity of thirst and dry mouth, oral health status and saliva PH values were evaluated in terms of differences between the groups.

Inclusion Criteria:

• patients who underwent major abdominal surgery under general anesthesia (due to lower and upper gastrointestinal tract malignancy)
• patients without oral and nasal disease
• patients who do not have vision, hearing, speech and understanding problems
• patients with American Society of Anesthesiologists (ASA) I and II scores
• patients over the age of 18

Exclusion Criteria:

• patients whose mouth and tongue mucosa integrity was degraded
• patients had a cognitive disorder
• patients had a neurological, renal, cardiac or pulmonary disorders that could affect the test results
• patients using psychoactive drugs