Dental surgery generally causes stress and fear, which may affect patient physiology and increase perioperative anxiety. Dental anxiety is considered to be an important factor in determining the need for intravenous sedation. One of the gold standards for measuring preoperative anxiety is Spielberger’s State-Trait Anxiety Inventory (STAI). The authors have previously assessed preoperative anxiety using STAI and recommended that intravenous sedation be performed for patients whose anxiety level is high. The intravenous cannulation necessary for sedation and sedation itself may increase anxiety. The authors carried out this study to examine whether planning intravenous sedation before surgery increases preoperative anxiety. The subjects were patients who planned to undergo wisdom teeth extraction under local anaesthesia in the authors’ hospital. They were divided into two groups on the basis of the planned intravenous sedation. STAI scores were compared between the initial visit and just before surgery. There were no significant differences in the state and trait anxiety scores between the initial visit and the day of the surgery in the two groups. Planned intravenous sedation based on the evaluation of anxiety levels using STAI is effective for promoting a safe operation without aggravating preoperative anxiety.
Anxiety regarding dental treatment is a common reaction to an unknown danger. Despite the remarkable advances in dentistry, patient anxiety continues to be a significant problem for dentists. Most people experience some anxiety before dental treatment, especially if they are about to undergo a procedure that they have never experienced before. The extraction of wisdom teeth is one of the most commonly performed surgeries in dentistry. It is an invasive, uncomfortable procedure that sometimes requires intravenous sedation or general anaesthesia. It generally causes stress and fear, which may affect patient physiology and increase perioperative anxiety.
Local anaesthesia is usually employed for the extraction of wisdom teeth, but injection of the gingiva, which is the first step in the operation, may cause pain and fear. Pain and fear may lead to extreme fluctuations in blood pressure and heart rate and cause serious complications such as vasovagal reactions. A preoperative treatment that decreases anxiety is therefore necessary to promote stress-free, comfortable, and safe surgery under local anaesthesia. Intravenous sedation has been found to be suitable for safe dental surgery in patients with high anxiety levels, but various studies have reported that many patients are anxious about the pain associated with intravenous cannulation for the administration of the sedative.
The Spielberger’s State-Trait Anxiety Inventory (STAI) can be used to evaluate the levels of state and trait anxiety. State anxiety is defined as a subjective feeling of nervousness, whereas trait anxiety is defined as an individual’s underlying tendency to perceive a situation as stressful or threatening. STAI is a validated and widely used instrument for measuring a patient’s preoperative anxiety. The authors have previously assessed preoperative anxiety using STAI and recommended that intravenous sedation be performed for patients whose level of state anxiety is higher than stage IV. However, venipuncture must be performed for intravenous sedation, which may itself increase the patient’s anxiety. In addition, while sedation is not associated with airway disorders or inadequate ventilation, responsiveness is attained by means of repeated painful stimulation. In the American Society of Anesthesiologists (ASA) sedation classification system, it cannot be classified as conscious sedation or deep sedation. Even if it is considered to be conscious sedation, there are many cases in which the patient does not have a memory of the time under sedation, and in many cases the patient recognizes a loss of consciousness. Therefore, some patients may fear sedation itself.
This study was performed to compare preoperative anxiety levels before and after the planning of intravenous sedation.
Patients and methods
The subjects were 111 patients whose physical status, as determined by the ASA, was I, and who planned to undergo wisdom teeth extraction under local anaesthesia in the authors’ hospital. STAI is the gold standard for measuring preoperative anxiety. STAI scores usually range from 20 to 80. In Japanese men and women, state anxiety is considered high when the STAI score is above 41 and 42, respectively, and trait anxiety is considered high when this score is above 44 and 45, respectively. STAI evaluates the degree of anxiety based on 5 stages ( Fig. 1 ). For example, a male state anxiety score above 50 is indicative of stage V anxiety, which is considered very high; a state anxiety score of 41–49 is indicative of stage IV anxiety, which is considered high. The authors assessed preoperative anxiety using STAI at the initial visit and recommended intravenous sedation for patients whose level of state anxiety was above stage IV. They also recommended the same sedation procedure to patients who anticipated high surgical invasion. All participants were asked to complete the STAI again just before surgery. The subjects were classified into two groups on the basis of the planned intravenous sedation. Patients who underwent surgery with only local anaesthesia, without planned intravenous sedation, were categorized in the IVS plan (−) group. Patients who underwent surgery with a combination of local anaesthesia and planned intravenous sedation were categorized in the IVS plan (+) group. STAI scores were compared between the initial visit and just before surgery. Each group was divided into three subgroups according to the overall STAI score at the initial visit: IVS (−)-III, IVS (−)-IV, IVS (−)-V, IVS (+)-III, IVS (+)-IV, and IVS (+)-V. The IVS (−)-III group included those patients whose STAI score at the initial visit was III, in whom the operation was planned using only local anaesthesia.
The study protocol was approved by the Ethical Review Board of Fukuoka University Hospital. Written informed consent was obtained from all patients after they were provided with an explanation of the treatment and whole-body management plan. The authors also considered gender-based differences in changes in the STAI score between the initial visit and the day of the operation.
STAI data were tested for normality of distribution using the Kolmogorov–Smirnov test. The data demonstrated good approximation to a normal distribution, and analysis of variance was therefore used to analyze changes in anxiety scores. Significance was established at p < 0.05.
None of the subjects had a contributory medical or psychological history. In no patients was the operation terminated because of non-cooperative behaviour. In no patients was the operation terminated because of sedation complications, and all patients were sedated in the absence of severe haemodynamic instability.
The demographic characteristics of all participants are summarized in Table 1 . The demographic characteristics of those participants in whom surgery was performed less than 2 weeks after the initial visit are summarized in Table 2 . Using the Kolmogorov–Smirnov test, a significant correlation was observed between the anxiety scores of all participants and those participants in whom surgery was performed less than 2 weeks after the initial visit.
|IVS (−) group||IVS (+) group|
|Number [male/female]||62 [18/44]||49 [21/28]|
|Age (years)||27.1 ± 9.6||27.9 ± 6.6|
|Period from initial visit to surgery (days)||19.3 ± 21.3||11.1 ± 5.9 *|
|IVS (−) group||IVS (+) group|
|Number [male/female]||32 [7/25]||42 [16/26]|
|Age (years)||28.6 ± 11.8||29.0 ± 6.4|
|Period from initial visit to surgery (days)||9.6 ± 4.1||9.6 ± 3.7|
There were no significant differences in the demographic characteristics of patients included in the IVS (−) and IVS (+) groups. The period from the initial visit to the surgery was significantly longer in the group IVS (−) than that in the group IVS (+).
There were no significant differences in the state and trait anxiety scores between the initial visit and the day of the surgery in the IVS (−) group and in the trait anxiety scores in the IVS (+) group. The state anxiety scores of the IVS (+) group were significantly higher at the initial visit than on the day of the operation. Overall, combined anxiety scores were significantly higher in the IVS (+) group than in the IVS (−) group ( Fig. 2 ).
Regarding IVS (−) and IVS (+) subgroups, IVS (−)-III was the most common subgroup in the IVS (−) group, and IVS (+)-V was the most common subgroup in the IVS (+) group ( Table 3 ). State anxiety significantly decreased in the IVS (−)-V and IVS (+)-V subgroups between the initial visit and the operation day, whereas it significantly increased in the IVS (+)-III group ( Fig. 3 ). A significant decrease in trait anxiety was observed in the IVS (−)-V and IVS (−)-III subgroups between the initial visit and the operation day ( Fig. 4 ). No other significant changes were observed in any other subgroups. Examining the subgroups separately for men and women showed that the state anxiety scores of the IVS (+)-III group in women were higher on the operation day compared with the initial visit ( Table 4 ). Similarly, the state anxiety scores of the IVS (−)-IV group in women and the IVS (−)-III group in men were higher on the operation day compared with the initial visit ( Table 4 ).
|Stage V||Stage IV||Stage III|
|IVS (−) group|
|Age [years]||26.9 ± 6.9||26.8 ± 6.8||27.4 ± 12.1|
|IVS (+) group|
|Age [years]||27.3 ± 6.8||26.8 ± 7.1||31.8 ± 3.2|
|Initial visit||Operation day|
|IVS (−) group|
|IVS (+) group|