Preoperative Anxiety In Adults Research Articles

Effects of Virtual Reality on Preoperative Anxiety in Adult Patients: An Updated Meta-analysis

PurposeTo determine the effectiveness of virtual reality (VR) on preoperative anxiety in adult patients. DesignA systematic review and meta-analysis of randomized controlled trials. MethodsA systematic search was carried out using PubMed, Web of Science, the Cochrane Library, Embase, CINAHL, Scopus, PsycINFO, China National Knowledge Infrastructure (CNKI), WANFANG DATA, Chinese Science and Technology Periodical Database (VIP), and Sino-Med from inception to December 18, 2022. All eligible randomized controlled trials published were included (published in English and Chinese). The Cochrane Collaboration “Risk of Bias” tool was used to assess the methodological quality of the included studies. Review Manager software 5.4 was used for data analysis. FindingsNine studies with sample sizes ranging from 72 to 255 and 1,046 participants were identified. The results of the meta-analysis showed that VR significantly reduced preoperative anxiety in adults (standardized mean difference = −0.48, 95% CI: −0.93 to −0.03, P = .04). Our results suggested that VR improved postoperative satisfaction scores more effectively compared with control care (mean difference = 15.29, 95% CI: 6.25 to 24.33, P = .0009). ConclusionsStudy results support that VR has a positive effect in reducing preoperative anxiety in adults. VR can also significantly improve patients' satisfaction after surgery. However, the results need to be further assessed due to the small sample sizes and high heterogeneity.

Design of a nursing psychoeducation program to reduce preoperative anxiety in adults.

IntroductionPreoperative anxiety, with its multifactorial origins, affects a wide range of surgical patients, leading to adverse physiological and psychological effects in the perioperative period. Customized, autonomous nursing interventions are needed to address individual person needs. The shift toward outpatient surgery emphasizes the need for restructured nursing approaches. Existing literature suggests that preoperative nursing consultations offer opportunities for assessing needs, providing information, and prescribing anxiety-reduction strategies. Psychoeducation, a specialized skill within mental health and psychiatric nursing, has proven effective in alleviating preoperative anxiety and reducing postoperative complications. The aim is to obtain and analyze the information reflecting nurses’ understanding of the design, structure, and operationalization of a psychoeducation program to reduce preoperative anxiety in adults.MethodsA qualitative, exploratory, descriptive study was conducted. Data were collected through a 90-min focus group session held online via Zoom Meetings videoconferencing platform. Inclusion criteria for the participant’s selection were established. The focus group was guided to deliberate on potential strategies for crafting effective psychoeducational interventions. Data collection ceased upon reaching theoretical saturation and gathered information was submitted for content analysis. Ethical procedures were ensured.ResultsOf the participants, 10 were specialist nurses (7 working in mental health and psychiatric nursing and the remaining in medical-surgical nursing), with an average age of 41 and an average of 15 years working in surgical services. The nurses selected the target population, the structure and content of the psychoeducation sessions, and the resources and addressed the perceived importance, effectiveness, and feasibility of the designed psychoeducation program.DiscussionThe study revealed the nurses’ understanding of the design of a psychoeducation program potentially effective in reducing preoperative anxiety in adults, in an outpatient surgery context. This result will allow the transfer of the produced knowledge to nurses’ professional practice reflecting lower levels of anxiety and promoting a better surgical recovery. This is an unprecedented study conducted in Portugal, adding substantial knowledge to the nursing discipline. However, further research into implementing psychoeducation in a surgical context is suggested aiming to consolidate the results of research already carried out internationally.

Virtual Reality–Based Intervention to Reduce Preoperative Anxiety in Adults Undergoing Elective Surgery

Preoperative anxiety is common among adult patients undergoing elective surgery and is associated with negative outcomes. Virtual reality (VR)-based interventions have been considered simpler, safer, and more effective for reducing anxiety in patients undergoing surgery than conventional care. To examine the effectiveness of a VR-based intervention with preoperative education in reducing preoperative anxiety among adult patients undergoing elective surgery. An assessor-blinded prospective randomized clinical trial was conducted to recruit adult patients aged 18 years or older who were scheduled for their first elective surgery procedure under general anesthesia within the next 2 to 4 weeks at a preanesthesia assessment clinic in Hong Kong from July to December 2022. Participants were randomly assigned to either an intervention group (an 8-minute immersive 360° VR video tour in the operating theater via a head-mounted display console) or a control group (standard care). The primary outcome of preoperative anxiety was measured using the Amsterdam Preoperative Anxiety and Information Scale (range, 6-30; higher scores indicate greater anxiety), and the secondary outcomes (ie, stress, preparedness, and pain) were assessed by Visual Analog Scale at 3 time points: baseline at beginning of clinical session (T0), at the end of the clinical session immediately after the intervention (T1), and before the surgery (T2). Pain, satisfaction levels, and postoperative length of stay were evaluated after the surgery (T3). Simulation sickness was assessed after the intervention by use of the Simulation Sickness Questionnaire. A generalized estimating equations model was applied to compare changes in outcomes over time. A total of 74 participants (mean [SD] age, 46.34 [14.52] years; 38 men [51.4%] and 36 women [48.6%]) were recruited and randomized to the control group (37 participants) and intervention group (37 participants). Compared with the control group, the VR-based intervention group showed significantly decreased preoperative anxiety at T1 (β, -5.46; 95% CI, -7.60 to -3.32; P < .001) and T2 (β, -5.57; 95% CI, -7.73 to -3.41; P < .001), lower stress at T1 (β, -10.68; 95% CI, -16.00 to -5.36; P < .001) and T2 (β, -5.16; 95% CI, -9.87 to -0.45; P = .03), and higher preparedness at T1 (β, 6.60; 95% CI, 0.97 to 12.19; P = .02). Satisfaction levels were significantly increased in the intervention group vs the control group (mean [SD] score, 81.35 [9.24] vs 65.28 [8.16]; difference, 16.07; 95% CI, 12.00 to 20.15; P < .001). No significant differences in pain and postoperative length of stay were found. The findings of this study suggest that a VR-based intervention is a feasible and effective way to reduce preoperative anxiety in adult patients undergoing elective surgery. Given the promising results of this study, further study in the form of large-scale, multicenter, randomized clinical trials with broader implementation is warranted. Chinese Clinical Trial Registry Identifier: ChiCTR2100051690.

A brief virtual reality intervention for pre-operative anxiety in adults

Virtual reality (VR) is a promising non-pharmacologic tool for managing health care anxiety. We assessed the feasibility and acceptability of a pre-operative VR intervention by adult patients and medical staff and measured anxiety in adult patients pre- and post-VR intervention. We recruited 30 patients scheduled to undergo oral surgery and 8 medical staff as participants. The patients completed a verbal demographic survey and rated their anxiety before the VR intervention and at 1 minute and 2 minutes post-intervention. We administered the Acceptability of Intervention Measure to the patients to measure their perceptions of the VR intervention and the Feasibility of Intervention Measure to the medical staff to assess their perception of VR implementation. We performed an analysis of variance to compare pre-operative anxiety over time and assess demographic differences. The patients showed high and consistent acceptability of the pre-operative use of VR among patients, but acceptability varied among medical staff. The patients experienced a statistically significant reduction of pre-operative anxiety (P = .003). A brief VR pre-intervention is highly accepted by and very beneficial for patients undergoing oral surgery, positively affecting anxiety reduction. The perception of VR by health care providers needs to be explored to increase acceptability.

Effectiveness of virtual reality in reducing preoperative anxiety in adults: A systematic review and meta-analysis.

To evaluate the impact of a virtual reality (VR) intervention on adult patients' preoperative anxiety, heart rate, respiration rate and blood pressure. A systematic review and meta-analysis of randomized controlled trials (RCTs). A librarian-designed search of the Cochrane Library, PubMed, Web of Science, EMBASE, CINAHL, CBM, CNKI and Wanfang databases was conducted to identify research studies in English or Chinese on RCTs from their inception to 31 May 2022. Detailed search strategies and the checklist are provieded in Supplementary files S1 and S2. Two researchers independently screened eligible studies. The Cochrane Handbook for Systematic Reviews of Interventions was used to assess the risk of bias in the included studies. A fixed- or random-effects meta-analysis model was used to determine the pooled mean difference based on the results of the heterogeneity test. This study included 11 articles with a total of 892 participants. VR distraction comprised five studies, and VR exposure consisted of six studies. The results indicated that VR could reduce preoperative anxiety in adult patients and VR exposure seems to be more effective. The results also indicated that VR intervention can effectively reduce patients' heart rate and blood pressure compared to traditional intervention methods, but had no significant effect on respiration rate. VR technology could relieve preoperative anxiety in adult patients through distraction or exposure. More well-designed RCTs containing a wider range of surgical types are needed to verify our findings before we can make strong recommendations. Our systematic review and meta-analysis show a positive effect of VR distraction and exposure interventions in reducing preoperative anxiety in adult patients. We suggest incorporating VR into preoperative procedures as an auxiliary way to reduce negative emotions in eligible patients. Our paper is a systematic review and meta-analysis and such details do not apply to our work.

Biological activity of Melatonin and Some Unexpected Effects of Dynamization

Melatonin was found in animals, plants and bacteria. In animals, it is a&#x0D; hormone that anticipates the daily onset of darkness. In animals, melatonin is the hormone of regulation of the circadian rhythms and physiological functions such as sleep timing, blood pressure regulation, seasonal reproduction and many others. Melatonin is known to aid in reducing the effects of jet lag Melatonin appears also to have some use against the sleep problems of people who work rotating or night shifts. Melatonin has many protective properties, such as converting cholesterol to bile, preventing oxidative stress, may help reduce some types of headaches and protect against radiation-induces cellular damage. Melatonin in comparison to placebo is effective for reducing preoperative anxiety in adults when given as premedication. Melatonin may also reduce postoperative anxiety. It appears to cause few side-effects as tested in the short term, up to three months, at low doses. Two systematic reviews in 2005 and 2006 showed that there were no adverse effects of exogenous melatonin in several clinical trials and those comparative trials found that the adverse effects headaches, dizziness, nausea and drowsiness were reported about equally for both melatonin and placebo. Prolonged-release melatonin is safe with long-term use of up to 12 months. However, «natural» melatonin does not mean the best. Melatonin is made of the animal tissue can be contaminated with viruses or proteins that may be dangerous. Mad cow disease may cause changes in supplements made from animal brain tissue. One of the ways of adverse reaction elimination is applying a dynamicizing form of melatonin.&#x0D; Materials and methods. Melatonin (Mel 3ch) was prepared and presented to us&#x0D; with pleasure by Pralnilov A. I. The main aim of the study is to examine the influence of dynamicizing form of melatonin on hair structure in white&#x0D; laboratory mice and rats, Chinese hamsters, 2 years old.&#x0D; During the experiment the following tasks were solved:&#x0D; 1) To examine normal hair structure in white laboratory mice and rats, Chinese hamsters and to study the influence of dynamicizing form of melatonin on animal hair structure.&#x0D; 2) To examine animal behaviour and appearance&#x0D; 3)To estimate mice strength before and after taking&#x0D; melatonin &#x0D; White laboratory mice which belong to the vivarium of Kirov State Medical Academy and rats which belong to the vivarium of Kirov State Agricultural Academy are taking dynamicizing form of melatonin (mel-3CH) in the dose of 5 drops per 20 ml of water during 14 days. After two groups of the animals are organized: control group (7 animals) and the experimental group (7 animals). The experimental animals were injected subcutaneously in the interscapular region by melatonin-retard in the dose of 1 mg per 1 animal. In the control group, this drug is not injected. Hair is held on the subject glass in the 15 % solution NaOH during 5 min.&#x0D; The first swimming of animals was conducted with the aim to randomize resistance to physical exercises of animals. Every male, one by one, is taken to cylinder with water d = 18 cm, h = 40 cm for free swimming. Temperature of water maintains is in the range 29-30 C.&#x0D; Results. The investigation has shown that the hair structure,&#x0D; fleece and activity of the rodents taking mel 3ch from the 5th to the 14th&#x0D; days are being improved. The animal hair becomes bright, healthy and&#x0D; thick. The microscopic examination showed perfect adhering of the cuticle to the cortical layer and that the bottom and the cortical layer had become&#x0D; dense. In the control groups the hair remained faint and tousled. The&#x0D; microscopic examination showed delamination of the cortical layer from the bottom and the cuticle; the bottom had broken structure. The study showed that white laboratory mice taking dynamicizing form of melatonin in the dose of 5 drops per 20 ml of water during 14 days had improved their hair structure and fleece quality. Compulsory swimming method confirmed that dynamicizing form of melatonin increased adaptability of the animals. The time of swimming was 2,5 times more in comparison with the control group.

Effectiveness of nursing interventions for preoperative anxiety in adults: A systematic review with meta‐analysis

The aim of this review and meta-analysis is to analyse the effectiveness of nursing interventions for the management of preoperative anxiety in adults. The perioperative process is a stressful situation for many people who are going to be operated and it can generate feelings of anxiety. Also, preoperative anxiety can appear in the perioperative period. Nursing management of preoperative anxiety through individualized interventions can be effective for reducing anxiety. A systematic review with meta-analysis was performed. CINAHL, CUIDEN, Pubmed, ProQuest and Scopus databases were consulted without restriction per year of publication. The search was conducted in February 2020. Experimental studies on nursing management in preoperative anxiety with adults sample (>18years) published in English and/or Spanish were included. All types of surgery were included in the review. A random effects meta-analysis was performed to estimate the effect size for preoperative anxiety measured with STAI. After the selection process n=9 quantitative studies with nursing interventions for preoperative anxiety were included. A preoperative educational and informative interview was used in six studies, one study used empathic interview, one used motivational interview and one used hand massage. The meta-analysis, including four studies using nursing interviews, had a sample of n=419 in the intervention group and n=445 in the control group. The mean difference in preoperative state anxiety measured with the STAI was in favour of the nursing intervention. Nursing interventions for patients who are going to be operated seems to have a positive impact in their preoperative anxiety. However, due to the low number of studies and the heterogeneity of the sample, more research is needed about the topic.

Melatonin for preoperative and postoperative anxiety in adults.

Anxiety in relation to surgery is a well-known problem. Melatonin offers an alternative treatment to benzodiazepines for ameliorating this condition in the preoperative and postoperative periods. To assess the effects of melatonin on preoperative and postoperative anxiety compared to placebo or benzodiazepines. We searched the following databases on 10 July 2020: CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science. For ongoing trials and protocols, we searched clinicaltrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform. We included randomized, placebo-controlled or standard treatment-controlled (or both) studies that evaluated the effects of preoperatively administered melatonin on preoperative or postoperative anxiety. We included adult patients of both sexes (15 to 90 years of age) undergoing any kind of surgical procedure for which it was necessary to use general, regional, or topical anaesthesia. One review author conducted data extraction in duplicate. Data extracted included information about study design, country of origin, number of participants and demographic details, type of surgery, type of anaesthesia, intervention and dosing regimens, preoperative anxiety outcome measures, and postoperative anxiety outcome measures. We included 27 randomized controlled trials (RCTs), involving 2319 participants, that assessed melatonin for treating preoperative anxiety, postoperative anxiety, or both. Twenty-four studies compared melatonin with placebo. Eleven studies compared melatonin to a benzodiazepine (seven studies with midazolam, three studies with alprazolam, and one study with oxazepam). Other comparators in a small number of studies were gabapentin, clonidine, and pregabalin. No studies were judged to be atlow risk of bias for all domains. Most studies were judged to be at unclear risk of bias overall. Eight studies were judged to be at high risk of bias in one or more domain, and thus,to be at high risk of bias overall. Melatonin versus placebo Melatonin probably results in a reduction in preoperative anxiety measured by a visual analogue scale (VAS, 0 to 100 mm) compared to placebo (mean difference (MD) -11.69, 95% confidence interval (CI) -13.80 to -9.59; 18 studies, 1264 participants; moderate-certainty evidence), based on a meta-analysis of 18 studies. Melatonin may reduceimmediate postoperative anxiety measured on a 0 to 100 mm VAS compared to placebo (MD -5.04, 95% CI -9.52 to -0.55; 7 studies, 524 participants; low-certainty evidence), and may reduce delayed postoperative anxiety measured six hours after surgery using the State-Trait Anxiety Inventory (STAI) (MD -5.31, 95% CI -8.78 to -1.84; 2 studies; 73 participants; low-certainty evidence). Melatonin versus benzodiazepines (midazolam and alprazolam) Melatonin probably results in little or no difference in preoperative anxiety measured on a 0 to 100 mm VAS (MD 0.78, 95% CI -2.02 to 3.58; 7 studies, 409 participants; moderate-certainty evidence) and there may be little or no difference in immediate postoperative anxiety (MD -2.12, 95% CI -4.61 to 0.36; 3 studies, 176 participants; low-certainty evidence). Adverse events Fourteen studies did not report on adverse events. Six studies specifically reported that no side effects were observed, and the remaining seven studies reported cases of nausea, sleepiness, dizziness, and headache; however, no serious adverse events were reported. Eleven studies measured psychomotor and cognitive function, or both, and in general, these studies found that benzodiazepines impaired psychomotor and cognitive function more than placebo and melatonin. Fourteen studies evaluated sedation and generally found that benzodiazepine caused the highest degree of sedation, but melatonin also showed sedative properties compared to placebo. Several studies did not report on adverse events; therefore, it is not possible to conclude with certainty, from the data on adverse effects collected in this review, that melatonin is better tolerated than benzodiazepines. When compared with placebo, melatonin given as premedication (as tablets or sublingually) probably reduces preoperative anxiety in adults (measured 50 to 120 minutes after administration), which is potentially clinically relevant. The effect of melatonin on postoperative anxiety compared to placebo (measured in the recovery room and six hours after surgery) was also evident but was much smaller, and the clinical relevance of this finding is uncertain. There was little or no difference in anxiety when melatonin was compared with benzodiazepines. Thus, melatonin may have a similar effect to benzodiazepines in reducing preoperative and postoperative anxiety in adults.

The Use of Virtual Reality to Reduce Preoperative Anxiety in First-Time Sternotomy Patients: A Randomized Controlled Pilot Trial

ObjectiveTo report the first randomized controlled trial to investigate if immersive virtual reality (VR) treatment can reduce patient perceptions of anxiety compared with a tablet-based control treatment in adults undergoing a first-time sternotomy. MethodsTwenty first-time sternotomy patients were prospectively randomized (blinded to investigator) to a control or VR intervention. The VR intervention was a game module “Bear Blast” (AppliedVR) displayed using a Samsung Gear Oculus VR headset. The control intervention was a tablet-based game with comparable audio, visual, and tactile components. The State-Trait Anxiety Inventory was administered before and after the assigned intervention. Self-reported anxiety measures between the control and VR groups were evaluated using an unpaired t test. Changes in self-reported anxiety measures pre- and post-intervention were evaluated with a paired t test for both the control and VR groups. The study took place from May 1, 2017, through January 1, 2019 (Institutional Review Board 16-009784). ResultsBoth control and VR groups were 90.0% male, with a mean ± SD age of 63.4 ± 9.11 and 69.5 ± 6.9 years, respectively. VR users experienced significant reductions in feeling tense and strained, and significant improvements in feeling calm when compared with tablet controls (P<0.05). They also experienced significant reductions in feeling strained, upset, and tense when compared with their own self-reported anxiety measure pre- and post-intervention (P<0.05). Critically, control patients had no change in these categories. ConclusionImmersive VR is an effective, nonpharmacologic approach to reducing preoperative anxiety in adults undergoing cardiac surgery and shows the validity and utility of this technology in adult patients.

Preoperative anxiety in adults - a cross-sectional study on specific fears and risk factors

BackgroundPreoperative anxiety comprising anesthesia and surgery related anxiety is common and perceived by many patients as the worst aspect of the surgical episode. The aim of this study was to identify independent predictors of these three anxieties dimensions and to quantify the relevance of specific fears particularly associated with anesthesia.MethodsThis study was part of a cross-sectional survey in patients scheduled to undergo elective surgery. Anxiety levels were measured with the Amsterdam Preoperative Anxiety and Information Scale (APAIS). Modified numeric rating scales (mNRS, range 0–10) were used to assess the severity of eight selected specific fears which were predominantly analyzed descriptively. Multivariate stepwise linear regression was applied to determine independent predictors of all three anxiety dimensions (APAIS anxiety subscales).Results3087 of the 3200 enrolled patients were analyzed. Mean (SD) total preoperative anxiety (APAIS-A-T, range 4–20) was 9.9 (3.6). High anxiety (APAIS-A-T > 10) was reported by 40.5% of subjects. Mean (SD) levels of concern regarding the eight studied specific fears ranged from 3.9 (3.08) concerning “Anesthesiologist error” to 2.4 (2.29) concerning “Fatigue and drowsiness” with an average of 3.2 (2.84) concerning all specific fears. Ranking of all specific fears according to mean mNRS scores was almost identical in patients with high versus those with low anxiety. Among nine independent predictors of anxiety, only 3 variables (female gender, negative and positive anesthetic experience) independently predicted all three APAIS anxiety subscales. Other variables had a selective impact on one or two APAIS anxiety subscales only. Female gender had the strongest impact on all three APAIS anxiety subscales. Adjusted r2 values of the three models were all below 13%.ConclusionsThe high variability of importance assigned to all specific fears suggests an individualized approach is advisable when support of anxious patients is intended. Considering independent predictors of anxiety to estimate each patient’s anxiety level is of limited use given the very low predictive capacity of all three models. The clinical benefit of dividing patients into those with high and low anxiety is questionable.Trial registrationGerman Registry of Clinical Trials (DRKS00016725), retrospectively registered.

A cross-sectional study on preoperative anxiety in adults

ObjectiveThe main objective of this study was a detailed comparison of the level of anxiety about surgery and anesthesia. Other objectives included the assessment of the prevalence and intensity of preoperative anxiety. MethodsThis cross-sectional single-center survey used the validated Amsterdam anxiety and information scale (APAIS) and a modified numeric rating scale (mNRS) to assess preoperative anxiety, anxiety about surgery and anxiety about anesthesia. Prevalences and intensities of anxieties were predominantly analyzed descriptively. Results3200 patients were enrolled and 3087 (57% females) were analyzed. 92.6% reported preoperative anxiety according to APAIS scores. The average total APAIS anxiety score (APAIS-A-T) was 9.9 (SD 3.6). 40.5% reported high anxiety (defined as APAIS-A-T > 10). Mean anxiety about surgery (APAIS-A-Su) was higher than mean anxiety about anesthesia (APAIS-A-An): 5.5 (SD 2.1) vs. 4.3 (SD 1.9), p < 0.0001. Accordingly, more patients were substantially more afraid (score difference > 2) of surgery (642, 20.8%, 95% CI 19.4–22.3) than of anesthesia (48, 1.6%, 95% CI 1.2–2.1). ConclusionPreoperative anxiety is still very common among adult patients scheduled to undergo an elective procedure. Therefore, it should be evaluated routinely. Anxiety about surgery and anxiety about anesthesia differ in many patients. For this reason, anxiety about surgery and anxiety about anesthesia should be assessed separately. This would allow providing a more individualized support of patients to cope with their anxiety and could require particular attention by the surgeon or the anesthetist.

Melatonin for pre- and postoperative anxiety in adults.

Anxiety in relation to surgery is a well-known problem. Melatonin offers an atoxic alternative to benzodiazepines in ameliorating this condition in the pre- and postoperative period. To assess the effect of melatonin on pre- and postoperative anxiety in adults when comparing melatonin with placebo or when comparing melatonin with benzodiazepines. The following databases were searched on 19 April 2013: CENTRAL, MEDLINE, EMBASE, CINAHL and Web of Science. For ongoing trials and protocols we searched clinicaltrials.gov, Current Controlled Trials and the World Health Organization (WHO) International Clinical Trials Registry Platform. We reran the search in October 2014. We will deal with any studies of interest when we update the review. Randomized, placebo-controlled or standard treatment-controlled, or both, studies that evaluated the effect of preoperatively administered melatonin on preoperative or postoperative anxiety. We included adult patients of both genders (15 to 90 years of age) undergoing any kind of surgical procedure in which it was necessary to use general, regional or topical anaesthesia. Data were extracted independently by two review authors. Data extracted included information about study design, country of origin, number of participants and demographic details, type of surgery, type of anaesthesia, intervention and dosing regimen, preoperative anxiety outcome measures and postoperative anxiety outcome measures. This systematic review identified 12 randomized controlled trials (RCTs) including 774 patients that assessed melatonin for treating preoperative anxiety, postoperative anxiety or both. Four of the 12 studies compared melatonin, placebo and midazolam, whereas the remaining eight studies compared melatonin and placebo only.The quality of the evidence for our primary outcome (melatonin versus placebo for preoperative anxiety) was high. More than half of the included studies had a low risk of selection bias and at least 75% of the included studies had a low risk of attrition, performance and detection bias. Most of the included studies had an unclear risk of reporting bias.Eight out the 10 studies that assessed the effect of melatonin on preoperative anxiety using a visual analogue scale (VAS) (ranging from 0 to 100 mm, higher scores indicate greater anxiety) showed a reduction compared to placebo. The reported estimate of effect (relative effect -13.36, 95% confidence interval (CI) -16.13 to -10.58; high quality evidence) was based on a meta-analysis of seven studies. Two studies did not show any difference between melatonin and placebo. Two studies comparing melatonin with midazolam using a VAS found no evidence of a difference in preoperative anxiety between the two groups (relative effect -1.18, 95% CI -2.59 to 0.23; low quality evidence).Eight studies assessed the effect of melatonin on postoperative anxiety. Four of these studies measuring postoperative anxiety 90 minutes postoperatively using a VAS did not find any evidence of a difference between melatonin and placebo (relative effect -3.71, 95% CI -9.26 to 1.84). Conversely, two studies showed a reduction of postoperative anxiety measured six hours after surgery using the State-Trait Anxiety Inventory (STAI) when comparing melatonin with placebo (relative effect -5.31, 95% CI -8.78 to -1.84; moderate quality evidence). Two studies comparing melatonin with midazolam using a VAS did not find any evidence of a difference between the two groups in postoperative anxiety (relative effect -2.02, 95% CI -5.82 to 1.78). When compared to placebo, melatonin given as premedication (tablets or sublingually) can reduce preoperative anxiety in adults (measured 50 to 100 minutes after administration). Melatonin may be equally as effective as standard treatment with midazolam in reducing preoperative anxiety in adults (measured 50 to 100 minutes after administration). The effect of melatonin on postoperative anxiety (measured 90 minutes and 6 hours after surgery) in adults is mixed but suggests an overall attenuation of the effect compared to preoperatively.

Efficacy and Safety of Melatonin as an Anxiolytic and Analgesic in the Perioperative Period

Melatonin possesses sedative, hypnotic, analgesic, antiinflammatory, antioxidative, and chronobiotic properties that distinguish it as an attractive alternative premedicant. A qualitative systematic review of the literature concerning the perioperative use of melatonin as an anxiolytic or analgesic in adult patients was carried out using the recommended guidelines provided by the Cochrane Handbook for Systematic Reviews of Interventions. Nine of the 10 studies showed statistically significant reduction of preoperative anxiety with melatonin premedication compared with placebo. An opioid-sparing effect or reduced pain scores were evident in five studies whereas three studies were contradictory. Thus, melatonin premedication is effective in ameliorating preoperative anxiety in adults, but its analgesic effects remain controversial in the perioperative period. Additional well designed randomized controlled trials are necessary to compare melatonin premedication with other pharmacological interventions, investigate its effect on more varied surgical populations, and to delineate its optimal dosing regimen.

Risk factors for preoperative anxiety in adults.

Patients who undergo surgery experience acute psychological distress in the preoperative period. The objective of this study was to identify and quantify the effect of risk factors for preoperative anxiety in adults. A cross-sectional study was performed with 592 inpatients scheduled for elective surgery. Age ranged from 18 to 60 years (ASA physical status I-III). Demographic information was collected using a structured questionnaire. The measuring instruments were a visual analog scale, the State-Trait Anxiety Inventory; the Montgomery-Asberg Depression Rating Scale, the WHO Self-Reporting Questionnaire-20, and the future self-perception questionnaire. Multivariate conditional regression modeling was used to control confounding factors and to determine independent predictors of preoperative anxiety, taking into account the hierarchical relationship between risk factors. High preoperative anxiety was associated with history of cancer (odds ratio (OR)=2.26) and smoking (OR=7.47), psychiatric disorders (OR=5.93), negative future perception (OR= 2.30), moderate to intense depressive symptoms (3.22), high trait-anxiety (3.83), moderate to intense pain (2.12), medium surgery (OR=1.52), female gender (OR=2.0), ASA category III (OR=3.41), up to 12 years of education (OR=1.36), and more than 12 years of education (OR=1.68). Previous surgery (OR= 0.61) was associated with lower risk for preoperative state-anxiety. History of cancer and smoking, psychiatric disorders, negative future perception, moderate to intense depressive symptoms, high trait-anxiety, moderate to intense pain, medium surgery, female gender, ASA category III, up to 12 years of education and more than 12 years of education constituted independent risk factors for preoperative state-anxiety. Previous surgery reduced the risk for preoperative anxiety.