Melatonin vs. midazolam premedication in children: a double-blind, placebo-controlled study:

The impact of oral melatonin on pain and anxiety reduction during venipuncture in pediatric patients: a double-blind randomized clinical trial

Background

Pain resulting from therapeutic procedures and injections is a prevalent source of stress for children. Immediate side effects of pain in infants include syncope, irritability, sleep disturbances, and nutritional issues. This study aimed to investigate the effects of oral melatonin on alleviating pain and anxiety in pediatric patients undergoing venipuncture.

Methods

This double-blind, randomized controlled trial was conducted in the pediatric emergency ward. Patients were randomly assigned to one of two groups; the intervention group received 0.5 mg/kg of oral melatonin (maximum 5 mg) 30 min before venipuncture, while the placebo group received an equivalent amount of a placebo 30 min before the procedure. Using the Face, Legs, Activity, Cry, Consolability (FLACC) scale, postcanulation fear, pain severity, compliance, and potential side effects were evaluated.

Results

In total, 202 patients (113 male and 89 female) in the intervention and control groups were included in the analysis. The mean pain score during venipuncture was 1.52±3.04 in the intervention group and 2.04±6.57 in the control group (P<0.001). In the intervention group, only 19 (18.8%) patients reported pain during venipuncture, whereas 79 (78.2%) patients in the control group reported pain (P<0.001). Less than half (44.6%) of the patients in the intervention group experienced anxiety during venipuncture, while the majority (94.1%) of the patients in the control group exhibited anxiety (P<0.001). The venipuncture success rate was 60.4% in the intervention group and 51.5% in the control group (P=0.257).

Conclusion

Administering 0.5 mg/kg of oral Melatonin 30 min before venipuncture reduces procedure-related pain and anxiety in pediatric patients and may be associated with higher venipuncture success rates.

Intravenous MELAtonin for prevention of Postoperative Agitation and Emergence Delirium in children (MELA-PAED): A protocol and statistical analysis plan for a randomized clinical trial

BACKGROUND

Emergence agitation and delirium in children remain a common clinical challenge in the post-anesthetic care unit. Preoperative oral melatonin has been suggested as an effective preventive drug with a favorable safety profile. The oral bioavailability of melatonin, however, is low. Therefore, the MELA-PAED trial aims to investigate the efficacy and safety of intraoperative intravenous melatonin for the prevention of emergence agitation in pediatric surgical patients.

METHODS

MELA-PAED is a randomized, double-blind, parallel two-arm, multi-center, superiority trial comparing intravenous melatonin with placebo. Four hundred participants aged 1-6 years will be randomized 1:1 to either the intervention or placebo. The intervention consists of intravenous melatonin 0.15 mg/kg administered approximately 30 min before the end of surgery. Participants will be monitored in the post-anesthetic care unit (PACU), and the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ-AS) will be performed on days 1, 7, and 14 after the intervention. Serious Adverse Events (SAE) will be assessed up to 30 days after the intervention.

RESULTS

The primary outcome is the incidence of emergence agitation, assessed dichotomously as any Watcha score >2 during the participant's stay in the post-anesthetic care unit. Secondary outcomes are opioid consumption in the post-anesthetic care unit and adverse events. Exploratory outcomes include SAEs, postoperative pain, postoperative nausea and vomiting, and time to awakening, to first oral intake, and to discharge readiness.

CONCLUSION

The MELA-PAED trial investigates the efficacy of intravenous intraoperative melatonin for the prevention of emergence agitation in pediatric surgical patients. Results may provide further knowledge concerning the use of melatonin in pediatric perioperative care.

The MAGIC trial: a pragmatic, multicentre, parallel, noninferiority, randomised trial of melatonin versus midazolam in the premedication of anxious children attending for elective surgery under general anaesthesia

BACKGROUND

Child anxiety before general anaesthesia and surgery is common. Midazolam is a commonly used premedication to address this. Melatonin is an alternative anxiolytic, however trials evaluating its efficacy in children have delivered conflicting results.

METHODS

This multicentre, double-blind randomised trial was performed in 20 UK NHS Trusts. A sample size of 624 was required to declare noninferiority of melatonin. Anxious children, awaiting day case elective surgery under general anaesthesia, were randomly assigned 1:1 to midazolam or melatonin premedication (0.5 mg kg-1, maximum 20 mg) 30 min before transfer to the operating room. The primary outcome was the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF). Secondary outcomes included safety. Results are presented as n (%) and adjusted mean differences with 95% confidence intervals.

RESULTS

The trial was stopped prematurely (n=110; 55 per group) because of recruitment futility. Participants had a median age of 7 (6-10) yr, and 57 (52%) were female. Intention-to-treat and per-protocol modified Yale Preoperative Anxiety Scale-Short Form analyses showed adjusted mean differences of 13.1 (3.7-22.4) and 12.9 (3.1-22.6), respectively, in favour of midazolam. The upper 95% confidence interval limits exceeded the predefined margin of 4.3 in both cases, whereas the lower 95% confidence interval excluded zero, indicating that melatonin was inferior to midazolam, with a difference considered to be clinically relevant. No serious adverse events were seen in either arm.

CONCLUSION

Melatonin was less effective than midazolam at reducing preoperative anxiety in children, although the early termination of the trial increases the likelihood of bias.

CLINICAL TRIAL REGISTRATION

ISRCTN registry: ISRCTN18296119.

Melatonin or its analogs as premedication to prevent emergence agitation in children: a systematic review and meta-analysis

BACKGROUND

Emergence agitation (EA) is a prevalent complication in children following general anesthesia. Several studies have assessed the relationship between melatonin or its analogs and the incidence of pediatric EA, yielding conflicting results. This meta-analysis aims to assess the effects of premedication with melatonin or its analogs on preventing EA in children after general anesthesia.

METHODS

PubMed, EMBASE, the Cochrane Library, ProQuest Dissertations & Theses Global, Web of Science, CNKI, Wanfang Data, clinicaltrials.gov, and WHO International Clinical Trials Registry Platform were searched until 25 November 2022. We included randomized controlled trials that assessed EA in patients less than 18 years old who underwent general anesthesia. We excluded studies that did not use a specific evaluation to assess EA.

RESULTS

Nine studies (951 participants) were included in this systematic review. Melatonin significantly reduced the incidence of EA compared with placebos (risk ratio 0.40, 95% CI 0.26 to 0.61, P < 0.01) and midazolam (risk ratio 0.48, 95% CI 0.32 to 0.73, P < 0.01). Dexmedetomidine remarkably decreased the incidence of EA compared with melatonin (risk ratio 2.04, 95% CI 1.11 to 3.73, P = 0.02).

CONCLUSIONS

Melatonin premedication significantly decreases the incidence of EA compared with placebos and midazolam. Dexmedetomidine premedication has a stronger effect than melatonin in preventing EA. Nevertheless, further studies are warranted to reinforce and validate the conclusion on the efficacy of melatonin premedication in mitigating EA in pediatric patients.

Age-Related Effects of Exogenous Melatonin on Anxiety-like Behavior in C57/B6J Mice

The synthesis of melatonin (MLT) physiologically decreases during aging. Treatment with MLT has shown anxiolytic, hypnotic, and analgesic effects, but little is known about possible age-dependent differences in its efficacy. Therefore, we studied the effects of MLT (20 mg/kg, intraperitoneal) on anxiety-like behavior (open field (OFT), elevated plus maze (EPMT), three-chamber sociability, and marble-burying (MBT) tests), and the medial prefrontal cortex (mPFC)-dorsal hippocampus (dHippo) circuit in adolescent (35-40 days old) and adult (three-five months old) C57BL/6 male mice. MLT did not show any effect in adolescents in the OFT and EPMT. In adults, compared to vehicles, it decreased locomotor activity and time spent in the center of the arena in the OFT and time spent in the open arms in the EPMT. In the MBT, no MLT effects were observed in both age groups. In the three-chamber sociability test, MLT decreased sociability and social novelty in adults, while it increased sociability in adolescents. Using local field potential recordings, we found higher mPFC-dHippo synchronization in the delta and low-theta frequency ranges in adults but not in adolescents after MLT treatment. Here, we show age-dependent differences in the effects of MLT in anxiety paradigms and in the modulation of the mPFC-dHippo circuit, indicating that when investigating the pharmacology of the MLT system, age can significantly impact the study outcomes.

Melatonin as a Potential Approach to Anxiety Treatment

Anxiety disorders are the most common mental diseases. Anxiety and the associated physical symptoms may disturb social and occupational life and increase the risk of somatic diseases. The pathophysiology of anxiety development is complex and involves alterations in stress hormone production, neurosignaling pathways or free radical production. The various manifestations of anxiety, its complex pathophysiological background and the side effects of available treatments underlie the quest for constantly seeking therapies for these conditions. Melatonin, an indolamine produced in the pineal gland and released into the blood on a nightly basis, has been demonstrated to exert anxiolytic action in animal experiments and different clinical conditions. This hormone influences a number of physiological actions either via specific melatonin receptors or by receptor-independent pleiotropic effects. The underlying pathomechanism of melatonin's benefit in anxiety may reside in its sympatholytic action, interaction with the renin-angiotensin and glucocorticoid systems, modulation of interneuronal signaling and its extraordinary antioxidant and radical scavenging nature. Of importance, the concentration of this indolamine is significantly higher in cerebrospinal fluid than in the blood. Thus, ensuring sufficient melatonin production by reducing light pollution, which suppresses melatonin levels, may represent an endogenous neuroprotective and anxiolytic treatment. Since melatonin is freely available, economically undemanding and has limited side effects, it may be considered an additional or alternative treatment for various conditions associated with anxiety.

Atomised intranasal dexmedetomidine versus oral melatonin in prevention of emergence delirium in children undergoing ophthalmic surgery with sevoflurane: A randomised double-blind study

BACKGROUND

Melatonin and dexmedetomidine have both been used as a premedication to decrease emergence delirium in children. The effectiveness of oral melatonin, compared with atomised intranasal dexmedetomidine, in this role is not well studied.

OBJECTIVE

To study the efficacy of pre-operative atomised intranasal dexmedetomidine versus oral melatonin in children scheduled for ophthalmic surgery under sevoflurane.

DESIGN

A prospective, randomised, double-blind trial.

SETTING

Ophthalmic surgery in a university teaching hospital, April 2021 to October 2021.

PATIENTS

A total of 120 children undergoing ophthalmic surgery with sevoflurane anaesthesia.

INTERVENTION

Children were randomised to receive pre-operative intranasal dexmedetomidine 2 μg/kg via an atomiser device (dexmedetomidine group) or oral melatonin 0.5 mg kg -1 (melatonin group), 45 min before surgery.

OUTCOMES MEASURED

The primary outcome was the incidence of emergence delirium assessed by the Paediatric Anaesthesia Emergence Delirium scale. Secondary outcomes included pre-operative sedation, quality of inhalational induction, postoperative sedation and pain.

RESULTS

The incidence of emergence delirium was lower in the dexmedetomidine group than in the melatonin group (17 versus 37%, relative risk 0.45, 95% CI: 0.24 to 0.88; P  = 0.01). Children in the dexmedetomidine group were more sedated following premedication and in the postanaesthesia care unit ( P  < 0.05). Postoperative pain scores were lower in the dexmedetomidine group than in the melatonin group: 0 [0 to 3] versus 2.5 [0-4], ( P  = 0.01). The requirement for and dose of rescue fentanyl analgesia postoperatively was comparable between the two groups.

CONCLUSION

Atomised intranasal dexmedetomidine significantly reduced emergence delirium in paediatric opthalmic procedures under sevoflurane anaesthesia compared to oral melatonin.

TRIAL REGISTRATION

Clinical Trials Registry of India CTRI/2021/03/032388 ( www.ctri.nic.in ).

Comparison of different sedatives in children before general anaesthesia for selective surgery: A network meta-analysis

WHAT IS KNOWN AND OBJECTIVE

It is estimated that 60% of children undergoing anaesthesia develop severe preoperative anxiety. The anxiety is associated with adverse reactions. Sedatives such as dexmedetomidine, midazolam, clonidine, ketamine, and melatonin can be used as premedication against preoperative anxiety. However, no consensus has been reached on the choice of pre-anaesthetic sedatives in children before selective surgery. Therefore, the current network meta-analysis (NMA) was carried out to evaluate different sedatives in children aged between 1 and 7 before general anaesthesia for selective surgery.

METHODS

Randomized clinical trials (RCTs) were retrieved from Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases from inception to October 22, 2021. Primary outcomes showed satisfactory sedation at parent separation and also at induction or mask acceptance. Secondary outcomes were those related to added benefits and side effects. The present NMA was conducted using the R software. Results of the study were reported as Relative Risk (RR) or Mean Difference (MD) at a 95% credible intervals (CrIs).

RESULTS AND DISCUSSION

A total of 48 trials were included in the present study. It was found that the effectiveness of dexmedetomidine, midazolam, clonidine, and ketamine were superior to that of placebo in satisfactory sedation at parent separation and induction or mask acceptance. There was no significant difference between melatonin and placebo in satisfactory sedation at induction or mask acceptance. Dexmedetomidine, ketamine, clonidine, and melatonin were superior to placebo in reducing emergence delirium (ED). In addition, midazolam prolonged the length of stay in the post anaesthesia care unit (PACU) as compared with placebo. Dexmedetomidine caused a significant reduction in systolic blood pressure (SBP) and heart rate (HR). Nevertheless, it was noted that the hemodynamic changes were roughly within safety limits.

WHAT IS NEW AND CONCLUSION

It was evident that the studied drugs can provide effective sedation with exception of melatonin and placebo. However, it was found that midazolam, ketamine, and clonidine lead to several side effects. The findings of the present study supported that dexmedetomidine, especially intranasal administration, has potential in the optimal selection of the sedatives for premedication in children. This is because the drug has effective sedation, reduced incidence of ED, side effects, and onset time.

Melatonin and aggressive behavior: A systematic review of the literature on preclinical and clinical evidence

The melatonin system and circadian disruption have well-established links with aggressive behaviors; however, the biological underpinnings have not been thoroughly investigated. Here, we aimed at examining the current knowledge regarding the neurobiological and psychopharmacological involvement of the melatonin system in aggressive/violent behaviors. To this end, we performed a systematic review on Embase and Pubmed/MEDLINE of preclinical and clinical evidence linking the melatonin system, melatonin, and melatoninergic drugs with aggressive/violent behaviors. Two blinded raters performed an independent screening of the relevant literature. Overall, this review included 38 papers distributed between clinical and preclinical models. Eleven papers specifically addressed the existing evidence in rodent models, five in fish models, and 21 in humans. The data indicate that depending on the species, model, and timing of administration, melatonin may exert a complex influence on aggressive/violent behaviors. Particularly, the apparent contrasting findings on the link between the melatonin system and aggression/violence (with either increased, no, or decreased effect) shown in preclinical models underscore the need for further research to develop more accurate and fruitful translational models. Likewise, the significant heterogeneity found in the results of clinical studies does not allow yet to draw any firm conclusion on the efficacy of melatonin or melatonergic drugs on aggressive/violent behaviors. However, findings in children and in traits associated with aggressive/violent behavior, including irritability and anger, are emerging and deserve empirical attention given the low toxicity of melatonin and melatonergic drugs.

Melatonin for pre-medication in children: a systematic review

Background

Melatonin’s effectiveness as an anxiolytic medication has been confirmed in adults; however, its efficacy in a paediatric population is unclear. A number of small studies have assessed its use in children as a pre-operative anxiolytic, with conflicting results.

Methods

We undertook a systematic review of pre-operative melatonin use in children. Four databases (MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and Web of Science), and ‘ClinicalTrials.gov’ were searched for ongoing and completed clinical trials of relevance. Citation tracking reference lists and relevant articles were also accessed. The review was unrestricted by comparator or outcomes. Eleven studies were judged eligible for inclusion. There were high levels of heterogeneity in melatonin administration (in terms of dose and timing). Variable outcomes were reported and included: anxiety; anaesthetic success; analgesia; sedation; post-operative recovery; and safety. Outcomes were not always assessed with the same measures.

Results

Evidence to support melatonin’s anxiolytic properties in this setting is conflicting. Melatonin was associated with reduced sedative effects, post-operative excitement and improved emergence behaviour, compared to comparator drugs. One study reported the benefit of melatonin use on sleep disturbance at two weeks post-surgery. No adverse safety events were identified to be significantly associated with melatonin, affirming its excellent safety profile.

Conclusion

Despite potential advantages, including improved emergence behaviour, based on current evidence we cannot confirm whether melatonin is non-inferior to current “usual care” pre-medications. Further consideration of melatonin as an anxiolytic pre-medication in paediatric surgery is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03149-w.

Effects of Melatonin Treatment on Perioperative Sleep Quality: A Systematic Review and Meta-Analysis with Trial Sequential Analysis of Randomized Controlled Trials

PURPOSE

Perioperative sleep disorders have attracted much attention due to their high prevalence and severe harm, and the current treatment methods are insufficient. Some randomized controlled trials (RCTs) have produced controversial results on whether melatonin can improve perioperative sleep quality. This review aimed to evaluate the effects of melatonin treatment on perioperative sleep quality.

PATIENTS AND METHODS

A systematic search of six databases was performed to identify RCTs investigating melatonin and perioperative sleep. The outcomes analyzed were subjective sleep quality, sleep latency (SL), total sleep time (TST), sleep efficiency (SE), the behavior of awakenings and daily naps, and the incidence of poor sleep quality. RevMan 5.4 and Stata 16 software was used for the meta-analysis and sensitivity analysis, and trial sequential analysis was conducted using TSA 0.9.5.10 Beta software. This study was registered in PROSPERO (registration number: CRD42022311378).

RESULTS

10 studies containing 725 participants were included. Melatonin improved postoperative subjective sleep quality (SMD: -0.30; 95% CI: [-0.47, -0.14]; P = 0.0004) but not preoperative sleep quality (MD: -2.76; 95% CI: [-10.44, 4.91]; P = 0.48). In the postoperative period, 6mg dose had the best efficacy (SMD: -0.31; 95% CI: [-0.57, -0.04]; P = 0.02). Melatonin increased postoperative TST (P = 0.02) and SE (P = 0.002) and decreased the incidence of postoperative poor sleep quality (P = 0.002) but had no effect on SL (P = 0.11), the number and duration of awakenings (P = 0.28; P=0.55), and the number and duration of daily naps (P = 0.26; P = 0.38). The trial sequential analysis showed that the accumulated Z value crossed both the traditional boundary value and the TSA boundary value, further confirming the stability of the result of the meta-analysis.

CONCLUSION

Melatonin treatment can improve postoperative sleep quality. A 6mg daily dose of melatonin may have a better beneficial effect, which needs further exploration. This study supports the application of melatonin for improving postoperative sleep quality.

Association of pharmacological prophylaxis with the risk of pediatric emergence delirium after sevoflurane anesthesia: An updated network meta-analysis

STUDY OBJECTIVE

This updated network meta-analysis aims at exploring whether the concurrent use of midazolam or antiemetics may enhance the efficacy of other pharmacological regimens for delirium prophylaxis in pediatric population after general anesthesia (GA).

DESIGN

Network meta-analysis (PROSPERO registration: CRD42020179483).

SETTING

Postoperative recovery area.

PATIENTS

Pediatric patients undergoing GA with sevoflurane.

INTERVENTIONS

Pharmacological interventions applied during GA with sevoflurane.

MEASUREMENTS

This network meta-analysis of randomized controlled trials (RCTs) was conducted with a frequentist model. PubMed, Embase, ProQuest, ScienceDirect, Cochrane CENTRAL, ClinicalKey, Web of Science, and ClinicalTrials.gov were searched from their inception dates to April 12, 2020, for RCTs of either placebo-controlled or active-controlled design containing information on the incidence of emergence delirium in pediatric patients undergoing sevoflurane anesthesia.

MAIN RESULTS

Seventy studies comprising 6904 participants were included for the analysis of 30 pharmacological interventions. Based on surface under the cumulative ranking curve (SUCRA) analysis, midazolam was ranked the lowest in therapeutic effect (SUCRA: 20%), while antiemetics as a monotherapy had no effect on delirium prophylaxis. However, there was a trend that most combination therapies with midazolam or antiemetics were superior to monotherapies for delirium prophylaxis. Subgroup analyses based on age (i.e., ≤7 years) and a validated scoring system (i.e., the Pediatric Anesthesia Emergence Delirium scale) for delirium also suggested a better efficacy of combination therapies than monotherapies. Overall, combination therapies with midazolam or antiemetics did not have a negative impact on the incidence of postoperative nausea and vomiting, length of stay in the postanesthesia care unit, or time to extubation. The dexmedetomidine-midazolam-antiemetic combination was the most effective strategy for the prevention of emergence delirium.

CONCLUSIONS

This network meta-analysis suggested that the incorporation of midazolam or antiemetics as adjuncts for combination therapies may have synergistic effects against pediatric postoperative emergence delirium. Future large-scale placebo-controlled RCTs are warranted to validate our findings.

Stakeholder perspectives on barriers and enablers to recruiting anxious children undergoing day surgery under general anaesthetic: a qualitative internal pilot study of the MAGIC randomised controlled trial

Background

The ‘Melatonin for Anxiety prior to General anaesthesia In Children’ (MAGIC) trial was designed to compare midazolam and melatonin as pre-medications for anxious children (aged five to fourteen), undergoing day-case surgical procedures under general anaesthesia. Low recruitment is a challenge for many trials, particularly paediatric trials and those in ‘emergency’ settings. A qualitative study as part of MAGIC aimed to gather stakeholder perspectives on barriers and enablers to recruitment.

Methods

Sixteen stakeholders from six sites participated in semi-structured interviews about their experiences of setting up the MAGIC trial and recruiting patients as part of the internal pilot. Data was analysed using framework analysis.

Results

Participants identified barriers and enablers to recruitment. Barriers and enablers related to the study, participants, the population of anxious children, practitioners, collaboration with other health professionals, ethics, specific settings and the context of surgical day units and the wider health system. Attempting to recruit anxious children from a surgical day unit is particularly challenging for several reasons. Issues include the practicalities of dealing with a child experiencing anxiety for parents/guardians; professional unwillingness to make things more difficult for families and clinicians and nurses valuing predictability within a busy and time-sensitive setting.

Conclusions

Multi-site RCTs face recruitment barriers relating to study-wide and site-specific factors. There are multiple barriers to recruiting anxious children due to undergo day-case surgery. Barriers across domains can interrelate and reinforce each other, reflecting challenges relating to populations and settings. For example, in the case of anxious children, parents and other health professionals are concerned about exacerbating children’s anxiety prior to surgery. They may look for ways to keep things predictable and avoid the uncertainty of an RCT. Pre-trial engagement work could help address concerns among collaborating health professionals.

Using rapid ethnography during set-up or an internal pilot to focus on how the protocol will be or has been operationalised in practice may help identify issues. Allowing time to reflect on the findings of internal pilots and implement necessary changes could facilitate higher recruitment during the main phase of a trial.

Trial registration

NIHR Trial Registration Number: ISRCTN18296119. Registered on October 01, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05425-z.

As part of multimodal anxiolysis oral melatonin but not midazolam decreases emergence delirium in children: A randomised, double-blind, placebo-controlled study

BACKGROUND

Pre-operative anxiety is a risk factor for emergence delirium in children and a multimodal approach including sedatives and nonpharmacological measures is the current strategy to tackle this anxiety. The efficacy of oral melatonin as a component of multimodal anxiolytic strategy to decrease emergence delirium is not well studied.

OBJECTIVE

The aim of this study was to evaluate the efficacy of a multimodal anxiolytic strategy including oral melatonin or midazolam to decrease emergence delirium after sevoflurane anaesthesia.

DESIGN

A randomised, double-blind, parallel arm, placebo-controlled trial.

SETTING

Tertiary care teaching hospital from July 2019 till January 2020.

PARTICIPANTS

Children in the age group of 3 to 8 years who received sevoflurane anaesthesia for elective ambulatory procedures.

INTERVENTIONS

Children were randomised to receive oral premedication with either melatonin 0.3 mg kg-1, midazolam 0.3 mg kg-1 or honey as placebo. All the children received standardised nonpharmacological measures involving multiple techniques to allay anxiety. The anaesthetic plan was also standardised.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of emergence delirium as assessed by the Watcha scale in the postanaesthesia care unit. The secondary outcomes were pre-operative anxiety assessed using a modified Yale Preoperative Anxiety scale, patient compliance with mask induction using the Induction Compliance Checklist and postoperative sedation.

RESULTS

Data from 132 children were analysed. Melatonin significantly reduced the incidence of emergence delirium compared to placebo: 27 vs. 50%, respectively, an absolute risk reduction of 23.3 [95% confidence interval 3.7 to 42.9), P = 0.03]. Melatonin also significantly reduced the risk of emergence delirium compared with midazolam: 27 vs. 56%, respectively, an absolute risk reduction of 29.2 (95% CI 9.5 to 48.8). The midazolam group had a similar incidence of emergence delirium as placebo. Sedation scores were similar in the three groups postoperatively. The incidence and score of pre-operative anxiety as well as the compliance with mask induction were similar in the three groups.

CONCLUSIONS

A multimodal anxiolytic approach including oral melatonin, as opposed to oral midazolam, significantly reduced emergence delirium after sevoflurane anaesthesia.

TRIAL REGISTRATION

CTRI/2019/06/019850 in Clinical Trial Registry of India (www.ctri.nic.in).

Comparison the Oral Premedication of Midazolam, Dexmedetomidine, and Melatonin for Children's Sedation and Ease of Separation from Parents before Anesthesia

Background:

Children’s fear of surgery and preoperative separation from parents can contribute to anxiety and distress in children undergoing surgery. The study addressed the comparable efficacy of oral premedication of midazolam, dexmedetomidine, and melatonin to alleviate preoperative anxiety and easing the children’s separation from parents.

Materials and Methods:

A double-blinded trial enrolled three equal-sized groups of children (n = 153, aged 2–10 years) undergoing elective surgery who received oral midazolam, melatonin, and dexmedetomidine 30 min before induction. The observation sedation score, and ease of separation, acceptance of drug both preceding and following premedication administration were assessed and recorded every 5min till anesthesia induction.

Results:

A significant difference was observed in the mean scores of sedation before premedication and after separation from parents, as well as in the degree of the separation when comparing between the midazolam and melatonin groups and the dexmedetomidine and melatonin groups (P < 0.001). The scores were significantly lower in the melatonin group than the other two groups, whereas no significant difference was found in those between the midazolam and dexmedetomidine groups, as well as in the acceptance of anesthesia induction between the midazolam and melatonin groups (P = 0.250). The differences were significant between the midazolam and dexmedetomidine groups (P = 0.002) and melatonin and dexmedetomidine groups (P < 0.001) and anesthesia induction was effective in the dexmedetomidine group than that in the other two groups.

Conclusion:

Dexmedetomidine is more effective in acceptance of anesthesia induction. Furthermore, the midazolam and dexmedetomidine groups indicated better ease of separation and sedation scores than melatonin.

Study on the preventive effect of ramelteon on the onset of sleep disorder after general anesthesia in patients with autism spectrum disorder: A study protocol

BACKGROUND

The persistent loss of consciousness caused by general anesthesia without the existence of repeated 90-minute cycles of non-REM and REM sleep might significantly disturb and suppress the cycle of normal physiological sleep in postoperative periods after general anesthesia. Patients with autism spectrum disorders (ASD) with existing circadian rhythm disorder are reported to rapidly deteriorate due to acute sleep disorder during the perioperative period after general anesthesia.A melatonin receptor agonist, ramelteon (Rozerem), which is a sleep cycle regulator, is used as a therapeutic drug for patients with sleep disorders, but there are no studies on the prevention of postoperative sleep disorder after general anesthesia.In this study, we investigate whether prophylactic administration of a sleep-inducing substance, a melatonin receptor agonist, is effective against sleep disorder after general anesthesia in patients with ASD.

METHODS/DESIGN

This study is intended for patients with ASD aged 12 years and above who undergo treatment at Nagasaki University Hospital, Isahaya General Hospital Dentistry, and Sasebo City General Medical Center Dentistry and undergo dental treatment under general anesthesia. A melatonin receptor agonist (Rozerem) will be taken 7 days prior and 7 days postsurgery in patients diagnosed with insomnia. A randomized comparison will be made between 2 groups: an experimental group that is additionally administered Rozerem and a control group.The primary endpoint is the incidence of NREM-REM sleep disorders that occur within 3 to 5 days after general anesthesia. The secondary endpoint is the incidence of circadian rhythm sleep disorders (rate of occurrence of sleep-retardation syndrome with drowsiness and strong fatigue).

DISCUSSION

Postoperative sleep disorders after general anesthesia has been reported in patients with ASD; however, effective preventive pharmacological treatments have not been established. A sleep cycle regulator, ramelteon (Rozerem), is used as a therapeutic drug for patients with sleep disorders by decreasing the difficulty of falling asleep in insomnia. If sleep disorder can be prevented after the administration of general anesthesia in patients with ASD, we can support social participation while maintaining their quality of life.

TRIAL REGISTRATION

The study was registered with the jRCT1071200030.

Melatonin for anaesthetic indications in paediatric patients: a systematic review

The favourable safety profile and ubiquitous nature of melatonin has led to an increase in its use in various clinical settings in adults and children. We performed a systematic review of published studies on the use of melatonin for anaesthetic indications in paediatric patients. To identify relevant articles, PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature, Web of Science and Scopus databases were searched. Study title and abstract screening, and full text review were performed by two reviewers. Twenty-seven eligible studies investigating melatonin use for anaesthetic indications were identified. Due to significant heterogeneity in study methodology, a quantitative synthesis of the published findings was not possible. The identified studies were therefore categorised by the indication for melatonin: analgesia, diagnostic sedation and as an anaesthetic adjunct. Melatonin use for anaesthetic-related indications is safe; may provide analgesia for inflammatory-associated pain in neonates and children before venepuncture; may decrease the need for, or replace, general anaesthesia for diagnostic procedures; and may serve as an anaesthesia adjunct before induction in paediatric patients.

Efficacy and safety of supplemental melatonin for delayed sleep-wake phase disorder in children: an overview

Delayed sleep–wake phase disorder (DSPD) is the most frequently occurring intrinsic circadian rhythm sleep–wake disorder, with the highest prevalence in adolescence. Melatonin is the first-choice drug treatment. However, to date melatonin (in a controlled-release formulation) is only authorised for the treatment of insomnia in children with autism or Smiths-Magenis syndrome. Concerns have been raised with respect to the safety and efficacy of melatonin for more general use in children, as melatonin has not undergone the formal safety testing required for a new drug, especially long-term safety in children. Melatonin is known to have profound effects on the reproductive systems of rodents, sheep and primates, as well as effects on the cardiovascular, immune and metabolic systems.

The objective of the present article was therefore to establish the efficacy and safety of exogenous melatonin for use in children with DSPD, based on in vitro, animal model and clinical studies by reviewing the relevant literature in the Medline database using PubMed.

Acute toxicity studies in rats and mice showed toxic effects only at extremely high melatonin doses (>400 mg/kg), some tens of thousands of times more than the recommended dose of 3–6 mg in a person weighing 70 kg. Longer-term administration of melatonin improved the general health and survival of ageing rats or mice. A full range of in vitro/in vivo genotoxicity tests consistently found no evidence that melatonin is genotoxic. Similarly long term administration of melatonin in rats or mice did not have carcinogenic effects, or negative effects on cardiovascular, endocrine and reproductive systems.

With regard to clinical studies, in 19 randomised controlled trials comprising 841 children and adolescents with DSPD, melatonin treatment (usually of 4 weeks duration) consistently improved sleep latency by 22–60 min, without any serious adverse effects. Similarly, 17 randomised controlled trials, comprising 1374 children and adolescents, supplementing melatonin for indications other than DSPD, reported no relevant adverse effects. In addition, 4 long-term safety studies (1.0–10.8 yr) supplementing exogenous melatonin found no substantial deviation of the development of children with respect to sleep quality, puberty development and mental health scores. Finally, post-marketing data for an immediate-release melatonin formulation (Bio-melatonin), used in the UK since 2008 as an unlicensed medicine for sleep disturbance in children, recorded no adverse events to date on sales of approximately 600,000 packs, equivalent to some 35 million individual 3 mg tablet doses (MHRA yellow card adverse event recording scheme).

In conclusion, evidence has been provided that melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in children, provided that it is administered at the correct time (3–5 h before endogenous melatonin starts to rise in dim light (DLMO)), and in the correct (minimal effective) dose. As the status of circadian rhythmicity may change during long-time treatment, it is recommended to stop melatonin treatment at least once a year (preferably during the summer holidays).

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Melatonin improves sleep onset without serious adverse effects in youths with DSPD. Change th text after the fourth bullet into: Melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in youths.

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Melatonin for indications other than DSPD, dose not cause relevant adverse effects.

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Long term melatonin treatment does not impair sleep, puberty, and mental health.

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Melatonin is an efficacious and safe chronobiotic drug for the treatment of DSPD in youths.

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Melatonin should be administered at the correct time and in the minimal effective dose.

Melatonin Use in Hospitalized Children for Non-Anesthetic Indications: A Systematic Review

Melatonin, a potent free radical scavenger, plays an important role in homeostasis of cell and organ physiology. The increased demand and synthesis from the pineal gland during times of oxidative stress suggests a potential benefit of melatonin supplementation during hospitalization for acute illness. Yet, the paucity of clinical studies for non-anesthetic-associated indications in pediatric populations hampers the safe, effective, and consistent use of melatonin. The objective of this study was to systematically review published studies of melatonin use for non-sedative and non-analgesic indications in hospitalized pediatric patients. We conducted a search of PubMed, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, and Scopus databases for articles on the use of melatonin for pediatric patients in a hospital setting. Thirteen eligible studies, all in neonates, were identified. Data elements extracted included study design, number of study subjects, indication for melatonin therapy, and melatonin regimen (formulation, dosage, and duration). Because study methodologies were very heterogeneous, a quantitative synthesis of the published findings was not possible. The identified studies were therefore categorized by the indication of melatonin (adjuvant-antioxidant or anti-inflammatory therapy) in the following specific disease states: (i) acute infections, (ii) respiratory distress syndrome, (iii) neurologic injury, and (iv) jaundice. The current data suggest that melatonin is safe for use in hospitalized neonates. Melatonin may be beneficial for reducing inflammatory markers in neonatal patients with disease states and clinical sequelae that are associated with increased inflammation and oxidative stress. Melatonin, in conjunction with phototherapy, is not superior to use of vitamin D with phototherapy for treatment of neonatal jaundice. However, studies in other pediatric populations are needed given widespread use across clinical inpatient settings.

Melatonin in neuropaediatric MRI: a retrospective study of efficacy in a general hospital setting

BACKGROUND

Melatonin may offer a safe and cheap alternative to general anaesthesia and sedatives in neuropaediatric MRI. The purpose of our study was to evaluate its efficacy during a daily scanning programme and to assess its financial benefit.

METHODS

Neuro-MRI scans, performed in a general hospital setting after administration of melatonin in 64 children aged 10 months-5 years, were retrospectively reassessed by an experienced paediatric neuroradiologist, rating them as diagnostically contributing or as failed. The financial benefit was calculated.

RESULTS

49/64 scans (77%) were diagnostically contributing, in 11 (22%) no movement artefact was seen in any sequence; 15/64 scans failed (23%), in 3/15 because of serious movement artefacts, in 12/15 the scan was not started. Repeat scans under general anaesthesia were performed in 17 cases (27%): in the 15 failed cases and in 2 cases initially assessed as failed, but were considered diagnostically contributing in the present study. The financial benefit at the time the scans were made was approximately 13,360 Euro.

CONCLUSIONS

In this retrospective study, the use of melatonin in neuropaediatric MRI, made during a daily scanning programme with a remote waiting room, was associated with a high success rate in infants and young children. A minority of scans had no movement artefacts, indicating most children were not asleep. The sleep-inducing effect of melatonin could therefore not be proven, but the high success rate may be attributed to the sedative and/or anxiolytic effect of melatonin. Only a minority of scans had to be repeated under general anesthesia, leading to a reduction of scan related costs.

Perioperative Oxidative Stress: The Unseen Enemy

Reactive oxygen species (ROS) are essential for cellular signaling and physiological function. An imbalance between ROS production and antioxidant protection results in a state of oxidative stress (OS), which is associated with perturbations in reduction/oxidation (redox) regulation, cellular dysfunction, organ failure, and disease. The pathophysiology of OS is closely interlinked with inflammation, mitochondrial dysfunction, and, in the case of surgery, ischemia/reperfusion injury (IRI). Perioperative OS is a complex response that involves patient, surgical, and anesthetic factors. The magnitude of tissue injury inflicted by the surgery affects the degree of OS, and both duration and nature of the anesthetic procedure applied can modify this. Moreover, the interindividual susceptibility to the impact of OS is likely to be highly variable and potentially linked to underlying comorbidities. The pathological link between OS and postoperative complications remains unclear, in part due to the complexities of measuring ROS- and OS-mediated damage. Exogenous antioxidant use and exercise have been shown to modulate OS and may have potential as countermeasures to improve postoperative recovery. A better understanding of the underlying mechanisms of OS, redox signaling, and regulation can provide an opportunity for patient-specific phenotyping and development of targeted interventions to reduce the disruption that surgery can cause to our physiology. Anesthesiologists are in a unique position to deliver countermeasures to OS and improve physiological resilience. To shy away from a process so fundamental to the welfare of these patients would be foolhardy and negligent, thus calling for an improved understanding of this complex facet of human biology.

The efficacy of benzodiazepines as acute anxiolytics in children: A meta-analysis

OBJECTIVE

Current practice guidelines do not recommend benzodiazepines for acute management of anxiety disorders in pediatric patients. However, in procedural settings, benzodiazepines are commonly used to relieve acute preprocedural stress. This meta-analysis examines the efficacy and tolerability of benzodiazepines as short-term anxiolytics in children.

METHOD

PubMed was searched for randomized controlled trials assessing the efficacy of benzodiazepines as short-term anxiolytics in pediatric patients. Twenty-one trials involving 1,416 participants were included. A fixed effects model was used to examine the standardized mean difference of improvement in anxiety levels compared to control conditions. In stratified subgroup and meta-regression, the effect of the specific agent, dose, timing, and setting of benzodiazepine treatment was examined.

RESULTS

A significant benefit was seen for benzodiazepines compared to control (standardized mean difference = 0.71 [95% confidence interval, 0.60-0.82], k = 24, z = 12.7, P < .001). There was also funnel plot asymmetry in this meta-analysis, suggesting some evidence of publication bias. Moderator analyses found that when benzodiazepines were used in dental or nonoperating room procedures, they were more effective than when they were used in operating room procedures (test for subgroup differences Q2 = 6.34, P = .04). Tolerability analysis revealed there was no significant difference in the risk of developing irritability or behavioral changes between benzodiazepine and control groups.

CONCLUSIONS

Benzodiazepines are effective and well-tolerated when used as short-term anxiolytics in procedural settings for pediatric patients. Further research is needed to determine whether benzodiazepines are effective in pediatric anxiety disorders.

Premedication with melatonin vs midazolam: efficacy on anxiety and compliance in paediatric surgical patients

Preoperative anxiety is a major problem in paediatric surgical patients. Melatonin has been used as a premedicant agent and data regarding effectiveness are controversial. The primary outcome of this randomized clinical trial was to evaluate the effectiveness of oral melatonin premedication, in comparison to midazolam, in reducing preoperative anxiety in children undergoing elective surgery. As secondary outcome, compliance to intravenous induction anaesthesia was assessed. There were 80 children undergoing surgery randomly assigned, 40 per group, to receive oral midazolam (0.5 mg/kg, max 20 mg) or oral melatonin (0.5 mg/kg, max 20 mg). Trait anxiety of children and their mothers (State-Trait Anxiety Inventory) at admission, preoperative anxiety and during anaesthesia induction (Modified Yale Pre-operative Anxiety Scale), and children's compliance with anaesthesia induction (Induction Compliance Checklist) were all assessed. Children premedicated with melatonin and midazolam did not show significant differences in preoperative anxiety levels, either in the preoperative room or during anaesthesia induction. Moreover, compliance during anaesthesia induction was similar in both groups.

CONCLUSIONS

This study adds new encouraging data, further supporting the potential use of melatonin premedication in reducing anxiety and improving compliance to induction of anaesthesia in children undergoing surgery. Nevertheless, further larger controlled clinical trials are needed to confirm the real effectiveness of melatonin as a premedicant agent in paediatric population. What is Known: • Although midazolam represents the preferred treatment as a premedication for children before induction of anaesthesia, it has several side effects. • Melatonin has been successfully used as a premedicant agent in adults, while data regarding effectiveness in children are controversial. What is New: • In this study, melatonin was as effective as midazolam in reducing children's anxiety in both preoperative room and at induction of anaesthesia.

A comparison of the effect of two doses of oral melatonin with oral midazolam and placebo on pre-operative anxiety, cognition and psychomotor function in children: A randomised double-blind study

Background and Aims:

Melatonin (MT), a naturally occurring pituitary hormone has a sleep promoting effect. There are very few studies on pre-operative oral MT (0.2–0.5 mg/kg) in children. We planned a study to assess the efficacy of oral MT in two doses and compare it with oral midazolam and placebo for pre-operative anxiolysis, sedation, maintenance of cognition and psychomotor skills, parental separation behaviour and venepuncture compliance.

Methods:

This prospective double-blind randomised study was conducted after ethical committee approval on 100 children aged 5–15 years, American Society of Anaesthesiologists physical status I and II undergoing elective surgery at our hospital from January 1, 2014, to December 31, 2014. Mentally disordered children were excluded from the study. They were randomised into four groups of 25 each (A, B, C, D) to receive either oral MT 0.5 mg/kg or 0.75 mg/kg or oral midazolam 0.5 mg/kg or placebo 45–60 min, respectively, before induction. The child's anxiety, cognition and psychomotor function before and after pre-medication, behaviour during the parental separation and venepuncture were appropriately scored. Kruskal–Wallis analysis of variance for intergroup and Wilcoxon matched pairs tests for intragroup comparisons of data were applied.

Results:

The four groups were comparable regarding mean age, weight and sex. The anxiety score reductions in the three groups when compared to placebo were statistically significant. Children receiving MT 0.75 mg/kg had maximum anxiolysis and venepuncture compliance (P < 0.05). Cognition was decreased with maximum sedation, successful parental separation and psychomotor impairment in the midazolam group (P < 0.05).

Conclusion:

Oral MT (0.5 mg/kg and 0.75 mg/kg) in children decreases pre-operative anxiety without impairing cognitive and psychomotor functions, the 0.75 mg/kg dose being most effective.

Use of melatonin in oral health and as dental premedication

Anxiety is a common problem in dentistry which could affect the correct treatment and involve failure. Oral premedication is needed to treat several anxious patients. Many people are so highly anxious that oral sedation is not effective and need to be under deep sedation or even general anaesthesia in order to receive dental care. In these patients, due to a high level of anxiety, even the insertion of an intravenous catheter can be difficult. Benzodiazepines have been the most commonly used anxiolytic in these cases, but many may be associated with paradoxical reactions. Melatonin has a good potential to be used in this field as alternative to benzodiazepines because it may induce a natural sleepiness and improve sedation. The purpose of this paper was to summarize what is known about the use of melatonin in oral health and as dental premedication in anxious dental patients. Databases were searched for the relevant published literature to 30 April 2015. The following search items were used in various combinations: melatonin, premedication, anxiety, dental, sedation and anaesthesia. Few articles were found about this aspect, and the use of melatonin is still a controversial aspect in dental field. More detailed/specific studies are necessary to extend the therapeutic possibilities of melatonin as premedication in dentistry.

Analgesic, anxiolytic and anaesthetic effects of melatonin: new potential uses in pediatrics

Exogenous melatonin is used in a number of situations, first and foremost in the treatment of sleep disorders and jet leg. However, the hypnotic, antinociceptive, and anticonvulsant properties of melatonin endow this neurohormone with the profile of a drug that modulates effects of anesthetic agents, supporting its potential use at different stages during anesthetic procedures, in both adults and children. In light of these properties, melatonin has been administered to children undergoing diagnostic procedures requiring sedation or general anesthesia, such as magnetic resonance imaging, auditory brainstem response tests and electroencephalogram. Controversial data support the use of melatonin as anxiolytic and antinociceptive agents in pediatric patients undergoing surgery. The aim of this review was to evaluate available evidence relating to efficacy and safety of melatonin as an analgesic and as a sedative agent in children. Melatonin and its analogs may have a role in antinociceptive therapies and as an alternative to midazolam in premedication of adults and children, although its effectiveness is still controversial and available data are clearly incomplete.

Preoperative anxiety management, emergence delirium, and postoperative behavior

Preoperative anxiolysis is important for children scheduled for surgery. The nature of the anxiety depends on several factors, including age, temperament, past hospitalizations, and socioeconomic and ethnic backgrounds. A panoply of interventions effect anxiolysis, including parental presence, distraction, and premedication, although no single strategy is effective for all ages. Emergence delirium (ED) occurs after the use of sevoflurane and desflurane in preschool-aged children in the recovery room. Symptoms usually last approximately 15 minutes and resolve spontaneously. The Pediatric Anesthesia Emergence Delirium scale is used to diagnose ED and evaluate therapeutic interventions for ED such as propofol and opioids.

The role of melatonin in anaesthesia and critical care

Melatonin is a neurohormone secreted by the pineal gland. It is widely present in both plant and animal sources. In several countries, it is sold over the counter as tablets and as food supplement or additive. Currently, it is most often used to prevent jet lag and to induce sleep. It has been and is being used in several clinical trials with different therapeutic approaches. It has sedative, analgesic, anti-inflammatory, anti-oxidative and chronobiotic effects. In the present review, the potential therapeutic benefits of melatonin in anaesthesia and critical care are presented. This article aims to review the physiological properties of melatonin and how these could prove useful for several clinical applications in perioperative management, critical care and pain medicine. The topic was handsearched from textbooks and journals and electronically from PubMed, and Google scholar using text words.

Steal induction in preschool children: is melatonin as good as clonidine? A prospective, randomized study

OBJECTIVES/AIMS

To investigate whether melatonin would be an alternative drug to clonidine for performance of steal induction.

BACKGROUND

Distress during induction might have a negative impact on postoperative behavior. A steal induction is a technique for smooth anesthesia induction, and clonidine has been the primary agent for this purpose. There are conflicting results regarding the efficacy of melatonin for premedication, but its sleep inducing properties have been shown in children.

METHODS

Pediatric patients ASA I and II were randomly assigned to receive either melatonin 0.3 mg·kg(-1) or clonidine 4 μg·kg(-1) orally. Primary outcome was the percentage of successful steal induction, while secondary outcomes were onset of sleep, overall quality of mask induction, and adverse events at emergence from anesthesia.

RESULTS

A total of 87 patients were included for analysis with a median age of 33 months (range, 12-71) and median weight of 14 kg (range, 8-26). A successful steal induction was performed in 88.4% of group C and 75% of group M (P > 0.05). Onset of sleep in these patients occurred after a median time of 45 min (range 10-60) in group C and 35 min (range 15-60) in group M (P > 0.05). Children not falling asleep after melatonin received the premedication at a significantly earlier time point compared to those falling asleep (P = 0.001).

CONCLUSIONS

Melatonin was effective for steal induction in 75% of children compared to 88% of children who had clonidine. Melatonin resulted less effective when administered early in the morning.

Melatonin does not attenuate dynamic cardiovascular and cerebrovascular reflex responses to acute hypotension in healthy men

Background

Melatonin has been shown to attenuate the reflex sympathetic increases that arise in response to orthostatic challenges. We tested the hypothesis that the attenuated sympathetic increase induced by melatonin premedication may weaken the arterial blood pressure (ABP) preserving the capability during acute hypotension, thereby altering dynamic cerebral autoregulation and causing a further decrease in cerebral blood flow (CBF).

Methods

Acute hypotension was induced in 12 healthy subjects by releasing bilateral thigh cuffs before and after an oral dose of melatonin (0.2 mg/kg). Heart rate (HR), arterial blood pressure (ABP), Modelflow estimate of cardiac output (CO), total peripheral resistance (TPR) and cerebral blood flow velocity (CBFV) by transcranial Doppler were measured.

Results

Steady state HR, the mean arterial pressure and CBFV were not altered 60 minutes after melatonin ingestion. Reduced systolic arterial pressure (ΔSAP), changes in HR (ΔHR), CO (ΔCO), and TPR (ΔTPR), ΔHR/ΔSAP and percentage restoration of SAP were not affected after a temporal decrease in ABP induced by thigh cuff release. In the cerebral circulation, melatonin did not affect changes in CBFV, cerebrovascular resistance index, the rate of regulation and percentage restoration of CBFV following a sudden decrease in ABP.

Conclusions

Contrary to our hypothesis, melatonin did not affect the rapid vasodilatory and recovery responses of cardiovascular and dynamic cerebral autoregulation. These results suggest that melatonin premedication may not impair ABP and CBF preserving capability induced by sudden postural changes or hemorrhage.

Melatonin utility in neonates and children

Melatonin (N-acetyl-5-methoxytryptamine) is an endogenously produced indoleamine secreted by the pineal gland and the secretion is suppressed by light. Melatonin is a highly effective antioxidant, free radical scavenger, and has anti-inflammatory effect. Plenty of evidence supports the utility of melatonin in adults for cancer, neurodegenerative disorders, and aging. In children and neonates, melatonin has been used widely, including for respiratory distress syndrome, bronchopulmonary dysplasia, periventricular leukomalacia (PVL), hypoxia-ischemia encephalopathy and sepsis. In addition, melatonin can be used in childhood sleep and seizure disorders, and in neonates and children receiving surgery. This review article discusses the utility of melatonin in neonates and children.

Perioperative effects of oral midazolam premedication in children undergoing skin laser treatment: a double-blinded randomized placebo-controlled trial

PURPOSE: To investigate and compare the efficacy of oral midazolam with two different dosages in orange juice on perioperative hemodynamics and behavioral changes in children who underwent skin laser treatment in an academic educational Hospital. METHODS: Ninety children, candidates for skin laser treatment were randomly assigned to 1 of 3 groups of 30 each: the placebo group received 0.1 ml/kg orange flavored juice, group 2 and 3 receiving 0.5 and 1 mg/kg of injectable midazolam mixed with an equal volume of orange juice, respectively. The main outcome measures included the mask acceptance, patients' behavioral scales and postoperative events. RESULTS: There were no significant differences in heart rate, respiratory rate, and systolic blood pressure among the three groups. However, arterial oxygen saturation was significantly reduced in those given 1 mg.kg-1 midazolam. The median scores of anxiety, separation from parent, preparing an intravenous line, acceptance of the oxygen mask, good sedation, crying reduction and consciousness level were better in midazolam group. Postoperative agitation and re-crying were also more frequent in placebo receivers. Those given 1 mg.kg-1 midazolam were significantly more optimal for sedation, crying, consciousness, preparing an intravenous line, and postoperative re-crying compared with 0.5 mg.kg-1 midazolam receivers. CONCLUSION: As a preanaesthetic medication, the 1 mg.kg-1 dose of orally given midazolam especially in a volume of orange juice and can optimize the children's behavior during skin laser treatment with no serious adverse effects, enhancing their parents' satisfactions about the sedative protocol.

Clinical uses of melatonin in pediatrics

This study analyzes the results of clinical trials of treatments with melatonin conducted in children, mostly focused on sleep disorders of different origin. Melatonin is beneficial not only in the treatment of dyssomnias, especially delayed sleep phase syndrome, but also on sleep disorders present in children with attention-deficit hyperactivity, autism spectrum disorders, and, in general, in all sleep disturbances associated with mental, neurologic, or other medical disorders. Sedative properties of melatonin have been used in diagnostic situations requiring sedation or as a premedicant in children undergoing anesthetic procedures. Epilepsy and febrile seizures are also susceptible to treatment with melatonin, alone or associated with conventional antiepileptic drugs. Melatonin has been also used to prevent the progression in some cases of adolescent idiopathic scoliosis. In newborns, and particularly those delivered preterm, melatonin has been used to reduce oxidative stress associated with sepsis, asphyxia, respiratory distress, or surgical stress. Finally, the administration of melatonin, melatonin analogues, or melatonin precursors to the infants through the breast-feeding, or by milk formula adapted for day and night, improves their nocturnal sleep. Side effects of melatonin treatments in children have not been reported. Although the above-described results are promising, specific studies to resolve the problem of dosage, formulations, and length of treatment are necessary.

Perioperative melatonin use

Melatonin is a substance chiefly produced by the pineal gland and has a key role in the sleep-wake cycle. It also has an important antioxidant role. Exogenous melatonin has a short half-life and is available in a range of preparations. Newer analogues targeted for the recently discovered melatonin MT1 and MT2 receptors have also been developed. Exogenous melatonin is used as a resynchronisation agent in jet lag and for other sleep disturbances. Perioperatively, melatonin has been used as a premedicant, sedative and analgesic. It decreases paediatric emergence delirium. The antioxidant properties of melatonin are being investigated for use in sepsis and reperfusion injuries. It would appear that patients on melatonin supplements should continue taking them perioperatively because there may be benefits. Melatonin and its analogues will be increasingly encountered in the perioperative setting.

Update on the use of melatonin in pediatrics

Melatonin, an endogenously produced indoleamine, is a highly effective antioxidant, free radical scavenger, and a primary circadian regulator. Melatonin has important antioxidant properties owing to direct and indirect effects. It directly scavenges reactive oxygen and reactive nitrogen species, prevents molecular oxidation, improves mitochondrial physiology, and restores glutathione homeostasis. Its indirect antioxidant effects stem from its ability to stimulate the activities of the enzymes involved in the glutathione cycling and production. Melatonin, by reducing free radical damage, may be an effective protective agent for the fetus as it is in adults. Several clinical studies on melatonin have shown that it reduces oxidative stress in human newborns with sepsis, hypoxic distress, or other conditions, where there is excessive free radical generation. A role of melatonin in infant development has also been suggested. Pineal dysfunction may be associated with deleterious outcomes in infants and may contribute to an increased prevalence of sudden infant death syndrome. Delayed melatonin production is evident in infants who had experienced an apparent life-threatening event. Melatonin has been used as a pharmacologic treatment for insomnias associated with shift work, jet lag, and delayed sleep onset in adults for decades. In children as well, melatonin has value as a sleep-promoting agent. Evidence suggests that melatonin has utility as an analgesic agent presumably related to its ability to release β-endorphin. The data support the notion that melatonin, or one of its analogs, might find use as an anesthetic agent in children.

Some questions provoked by a chronic headache (with mixed migraine and cluster headache features) in a woman with a pineal cyst. Answers from a literature review

The main known function of the pineal gland in humans is the production of melatonin. Benign cysts of the gland have been related to headache, although the mechanism of production of this assumed clinical manifestation has not been clearly determined, due to the lack of large prospective studies. The question is complicated by the fact that pineal cysts are frequently found on brain magnetic resonance imaging. Much has been published about the possible role of benign pineal cysts in the pathophisiology of headaches and the potential of melatonin in headache therapy, as well as in other disorders. The aim of this article is to review the current state of the suject. We have tried to place accurately the relation between headache and pineal cysts based on the available evidence, as well as the actual role of melatonin in physiology and pharmacology, more specifically in headache therapy. We include a clinical case to illustrate the subject.

Evidence-based clinical update: does premedication with oral midazolam lead to improved behavioural outcomes in children?

PURPOSE

The purpose of this evidence-based clinical update was to identify the best evidence to determine if behavioural outcomes are improved in children after oral midazolam premedication.

METHODS

A literature search was conducted using both PubMed and OVID programs, utilizing the terms "midazolam", and either "premedication" or "preoperative treatment". Search limits that were employed included randomized controlled trials (RCTs), English language, human studies, children aged 0-18 yr, and publication dates 1990 - present (January 2006). A review of the 171 abstracts obtained was undertaken and, of these, 30 papers were identified that concerned oral midazolam in children prior to general anesthesia, and that involved a RCT with a placebo or control arm. These studies were assigned levels of evidence, and grades of recommendation were made according to Centre for Evidence-Based Medicine criteria.

RESULTS

Oral midazolam premedication in children was found to reduce the anxiety associated with separation from parents/guardians, and with induction of anesthesia. Recovery times are not significantly delayed. There is no consistent evidence to suggest a reduction in the phenomenon of emergence agitation. Evidence suggesting an improvement in behavioural outcomes at home is also inconsistent.

CONCLUSION

Premedication with midazolam 0.5 mg x kg(-1) po administered 20-30 min preoperatively, is effective in reducing both separation and induction anxiety in children (grade A recommendation), with minimal effect on recovery times. However improved postoperative behavioural outcomes in the postanesthesia care unit, or at home cannot be predicted on a consistent basis.