As a very threatening stressor, surgery often leads to strong psychological stress reactions in surgical patients before surgery, the most typical of which is anxiety. According to previous studies, more than 60% of children have severe anxiety during induction of anesthesia. Preoperative anxiety in children is not only significantly related to postoperative adverse physiological and psychological changes such as delirium during recovery from anesthesia, postoperative pain, and sleep disturbance, but also has a serious negative impact on their future study and life (such as timidity, nocturia, etc.), even for several years. Moreover, if the child is uncooperative, crying violently, and refuses to enter the operating room due to preoperative psychological stress, coercive measures are often adopted in clinical practice, which can easily cause harm to the physical and mental health of the child. Therefore, effective interventions to reduce pre-operative anxiety in children is an urgent need.

At present, most researches adopt different interventions to improve the preoperative anxiety of children. Several studies have explored to the efficacy of psychological interventions and virtual reality exposure in reducing preoperative anxiety in children undergoing surgery,results suggest that these interventions can reduce preoperative anxiety and postoperative pain in children. Through toys and video games, researchers verified the effects of psychological preparation on perioperative stress, anxiety, and mood in children undergoing cardiac surgery. In addition, researchers also conducted specialized games, interest induction, childlike and diversified nursing methods to relieve preoperative anxiety in children. Although these interventions have achieved certain effects, the intervention strategies need professionals accompanied and special arrangements, there also exist problems such as time-consuming, labor-intensive, and limited audience, especially during the peak operation period.

Attention distraction is an emotion regulation strategy commonly used in daily life, which actively separates the individual's attention from negative emotions and points to neutral or positive stimuli. Music and animation are the most common and affordable distraction strategies to reduce preoperative anxiety in children, but their effects are inconsistent. It is worth noting that Chow believe that the effect of the combination of audio and video is better than that of music intervention. Moreover, previous studies confirmed that when a mental image is experienced, there is an associated emotion that connects the feeling state with the mind and body leading to a physiologic change.

Therefore, this study intends to use two distraction strategies (music and animation) in pediatric surgery patients to compare the effects of the two strategies on preoperative anxiety, anesthesia induction cooperation, vital signs, and to explore effective methods to improve preoperative anxiety in children.

This study was a randomized controlled trial according to the CONSORT guidelines.Researchers recruited child patients(3-12 years) from a general tertiary hospital in Changsha, Hunan province, China. Researchers divided the subjects into three groups, animation group, music group and control group. The 181 patients recruited were randomized into three groups. Instruments, including preoperative anxiety,the degree of cooperation of children during anesthesia induction ,heart rate and blood pressure were assessed at the three moments: before entering the operating room (baseline T0), entering the operating room(T1), and before induction of anesthesia(T2). The repeated-measures analysis of variance were used to analyze the data.

The study was a single blind, randomized, controlled trial.Researchers recruited subjects from one Central South University-affiliated general tertiary hospital in Changsha, Hunan province, China. And the whole trail was on the basis of the CONSORT statements.Study procedures were approved by the institutional review boards of all participating centers before data collection began. All patients were screened by researchers for eligibility and then enrolled in the study if eligible and if the provided consent.

According to the statistics of the operation center, the main types of operations performed on children are adenoidectomy, tonsillectomy and pediatric occult penile surgery. The literature shows that the age of children undergoing tonsillectomy and adenoidectomy is concentrated in 4-12 years old, and the children with hidden penis surgery are concentrated in 3-12 years old. Therefore, the age for the patients were from 3 to 12 years.Researchers explained the study purposes,procedures, benefits, and risks involved orally to children's parents and participants were recruited with their parents' informed consent.

According to the sequence of the children entering the study, each group(animation group, music group and control group) of 3 persons was randomly divided into 3 subjects in each block according to the random number table. The blind copy shall be kept by the personnel of the unit who have nothing to do with the experiment. The randomization plan will be saved by the statistician, and the researcher only has the number of each subject. After opening the envelope according to the number, the researcher knew whether the subject is the control group or the intervention group. Investigators involved in the intervention were not involved in the analysis of the study data.

In the music group, on the basis of the routine preoperative care, the preferred music was selected from the music library as the intervention content on the day of surgery according to the preference of the children in the 1-day preoperative visit. If there was no preference, the music was played randomly. During the intervention, the same multimedia audio system (Wanderer EDIFIER R1700BT) was used to play music for 30-40 minutes, the volume was controlled at 35-80dB, and adjusted in time according to the feedback of the children.The children in animation group also chose their favorite cartoons as the intervention content on the basis of preoperative care. The same pad (Lenovo TB3-850F) was used to play pre-selected cartoons, and volume as the music group. During the intervention period, the children in intervention group were also accompanied by a nurse, who was also responsible for the implementation and maintenance of the intervention program.

In the control group, the children were received the routine care. One day before the operation, nurses from operating room conducted routine preoperative visits, they communicated effectively with the children and their families, and conducted psychological counseling. The visit time lasted nearly 30 minutes. On the day of surgery, all children were admitted to a special waiting room for children 0.5 h in advance, and venipuncture was performed by a circuit nurse. Colorful cartoon patterns were depicted on the walls of the waiting room, and various toys for children were placed indoors. After entering the operating room, the child was accompanied by a parent in the waiting room for the child to wait for surgery. During the period, a nurse in the research group gave routine psychological comfort, preoperative guidance, answered questions about anesthesia and surgery raised by the children and their parents. Before anesthesia induction, the child was brought into the operating room for anesthesia induction and surgery by operating room nurse, anesthesiologist, and surgeon, while the child's parents leave the waiting room and wait outside the operating room.

The researchers assessed the children's anxiety status, the degree of cooperation during the induction of anesthesia, and recorded the heart rate and blood pressure of the children at three moments: before entering the operating room (baselineT0), entering the operating room(T1), and before induction of anesthesia(T2).Before data collection, researchers who conducting data collection should be trained in measurement tools and assessment methods. The training contents mainly include: (1) explaining the purpose, meaning and the scoring method of the measurement tools; (2) Scoring the child's anxiety through pictures at three time points, discussing the reasons for consistent or inconsistent results, and repeating until the coefficient of agreement κ≥0.8.

Inclusion Criteria:

• With age from 3 to 12 years old;
• Had normal mental, psychological and intellectual development;
• Must receive general anesthesia surgery;
• Must be volunteered to join the study.

Exclusion Criteria:

• Receive an emergency surgery;
• With unstable vital signs or critical illness.

The process of data collection cost a lot of human and material resources, some of the data was privacy information of participants, and so on. Considering this, it is improper to share these data.

All patients were screened by researchers for eligibility and then enrolled in the study if eligible and if they provided consent. We divided the subjects into three groups, animation group, music group and control group. According to the 1:1:1 balance of three groups, the statistician set the block length to 3, and carried out a random design of the single-blind block group. According to the sequence of the children entering the study, each group of 3 persons was randomly divided into 3 subjects in each block according to the random number table. The blind copy shall be kept by the personnel of the unit who have nothing to do with the experiment. The randomization plan will be saved by the statistician, and the researcher only has the number of each subject. After opening the envelope according to the number, they know whether the subject is the control group or the intervention group. Investigators involved in the intervention were not involved in the analysis of the study data.