Various nonpharmacological methods are used in reducing the pain of children. One of these non-pharmacological methods is the guided imagery method. In the guided imagery method, the imagination of children is used. It is possible to have children imagine by being guided with audible stimulus and, therefore, distract their attention from the procedure or pain/discomfort feeling. The aim of this study was to determine the effect of the guided imagery method on procedural pain level, heart rate, and oxygen saturation values of the children within the age range of 8-12 years. The sample size of the study has been determined by the power analysis (G\*Power 3.1.9.2), in line with the results obtained from the studies which have been conducted using a similar research method. The sample size was found to be a total of 144 children including minimum of 72 children for each group. It was estimated that case losses may occur and therefore, it was decided to conduct the study with a total of 154 children including 77 children in two groups. One child in the guided imagery group was excluded from the study as he/she gave up listening to voice recording during the procedure and 1 child whose procedure could not be completed at once. In the control group, 1 child who felt nauseous during the procedure and 1 child whose procedure could not be completed at once could not be included in the sample group. Therefore, the sample group was composed of a total of 150 children including 75 children in each group. Information Form, Faces Pain Scale-Revised (FPS-R), and Visual Analogue Scale (VAS) were used for data collection.

Children and their parents who applied to the clinic for venipuncture were informed about the study. information about children and their parents included in the study were asked by the researcher through face-to-face interview and these data were recorded in 'Information Form' ten minutes before the procedure. FPS-R was explained to the children and they were asked whether or not they had pain before the procedure and they were asked to perform marking on the scale. Also, the children were told that they would mark the pain score again after the procedure. The parent was informed about 10-point VAS. Parent and observer (healthcare professional) marked children's pain level on the VAS independently by using a ruler. The researcher measured and recorded the pain level on the information form. The pulse oximeter device was attached to the finger of the extremity of the child that was not used for blood drawing. The children in the guided imagery group were informed that they would start to listen to voice recording named 'Stroll in the Forest' before venipuncture and blood would be drawn while they were listening to the voice recording. Also, children were asked to close their eyes, imagine the text content, and focus on the voice recording while listening to the voice. Thus, it was aimed to distract the children's attention from the procedure. One minute before venipuncture, children wore an earphone and voice recording started. As routine venipuncture procedure would be performed for the children in the control group, they were informed about the venipuncture procedure. Pre-procedure heart rate and oxygen saturation values of the children in the guided imagery group were determined and recorded just before attachment of tourniquet at the 50th second of the voice recording and then tourniquet was attached and blood drawing was started. Heart rate and oxygen saturation values of the children in the control group before attaching the tourniquet were written and then tourniquet was attached and then venipuncture was conducted. The blood of all the children included in the study was drawn by the experienced laboratorian working in the clinic using the 21 G needle-type injector. There was needle insertion in both control and guided imagery groups and when the first blood was seen in injector, the heart rate and oxygen saturation were recorded. Immediately after the injector was removed, the heart rate and oxygen saturation were recorded. Just after the procedure, children were asked to mark the pain level they felt during the procedure on FPS-R. The parent and observer evaluated the pain level of the children during the procedure using VAS.