Consulta de preanestesia no presencial en niños: experiencias y recomendaciones / Telemedicine pre-anesthesia evaluation in children: Experiences and recommendations

Desde hace años se realizan consultas y seguimiento de pacientes de forma no presencial. Durante la pandemia de COVID-19 diferentes sociedades han recomendado potenciar las consultas telemáticas. La consulta preanestésica no presencial es un acto médico que debe incluir los objetivos básicos de evaluación, preparación, información y obtención del consentimiento. Se debe disponer de medios y tiempo para realizarla. Al comienzo de la consulta debe identificarse el médico y el o los progenitores. La consulta preoperatoria no presencial es especialmente útil en niños ASA I y II que van a someterse a cirugías de bajo riesgo, a una reintervención o a procedimientos diagnósticos. Aquellos pacientes que requieran una exploración física, más allá de la posible de manera telemática, deberán citarse en la consulta presencial. El personal de enfermería puede participar de forma activa en este proceso siempre y cuando el anestesiólogo supervise todo el proceso, tome todas las decisiones sobre el procedimiento y sea el responsable de la información que se da a los padres y al niño, aclarando personalmente cualquier duda. El anestesiólogo debe informar del procedimiento, sus riesgos, incluidos los personalizados, y alternativas. Se registrará en la historia clínica que se ha informado, cuándo y a quién. EL anestesiólogo firmará el Consentimiento Informado haciendo figurar la fecha que da la información y los padres deberán firmarlo antes de la intervención.(AU)

Medical consult and follow-up of patients have been carried out remotely for years. During the COVID-19 pandemic, different societies have recommended promoting online consultations. The remote pre-anesthetic consultation is a medical act that must include the basic objectives of evaluation, preparation, information and obtaining consent. You must have the resources and time to do it. At the beginning of the consultation, the doctor and the parent(s) must be identified. Non-face-to-face preoperative consultation is especially useful in ASA I and II children evaluated for low-risk surgeries, reintervention, or diagnostic procedures. Those patients who require a physical examination, beyond that possible electronically, should make an appointment in the face-to-face consultation. The nursing staff can actively participate in this process as long as the anesthesiologist supervises the entire process, makes all decisions about the procedure and is responsible for the information given to the parents and the child, personally clarifying any doubts. The anesthesiologist must inform about the procedure, its risks, including personalized ones, and alternatives. It will be recorded in the medical history the information given, when and to whom. The anesthesiologist will sign the Informed Consent stating the date that the information is given, and the parents must sign it before the intervention.(AU)

Successful Premedication With Sublingual Midazolam Using a Suction Toothbrush.

Premedication is often used to reduce the stress associated with anesthesia-related procedures. However, in some cases, patients may not cooperate with medication delivery because of significant fear and anxiety. We report a case of an uncooperative patient with severe intellectual disabilities who was successfully premedicated with the unique technique of sublingual midazolam administration using a suction toothbrush. The 38-year-old male patient was planned to receive dental treatment under deep intravenous sedation (IVS), but he refused both intravenous cannulation and mask induction. Preanesthetic medication delivery using other routes was attempted but not accepted. As the patient tolerated toothbrushing, we used repeated practice with sublingual water administration through the toothbrush's suction hole to gradually desensitize the patient. Using that same method, sublingual midazolam was administered as a successful premedication to allow placement of a face mask for inhalational induction without distress and completion of the dental treatment under IVS. For patients who refuse other premedication routes, sublingual administration during toothbrushing with a suction toothbrush may provide a successful alternative.

Comparison between oral midazolam versus oral ketamine plus midazolam as preanesthetic medication in autism spectrum disorder: double-blind randomized clinical trial

Abstract Background: Conventional dental care is often impossible in patients with Autism Spectrum Disorder (ASD). Non-collaborative behaviors, sometimes associated with aggressiveness, are usual justifications for premedication in this population. Thereby, this research focuses on the effects of oral midazolam versus oral ketamine plus midazolam as preanesthetic medication in ASD. Methods: The sample included 64 persons with ASD, aged 2-59 years, scheduled for dental care under general anesthesia. The primary objective of this study was to compare degrees of sedation between two parallel, double-blinded, equally proportional groups randomized to receive oral midazolam (0.5 mg.kg−1, maximum 15 mg) or oral midazolam (0.5 mg.kg−1) associated with oral S(+)-ketamine (3 mg.kg−1, maximum 300 mg). The secondary outcomes were the need of physical stabilization to obtain intravenous line, awakening time, and occurrence of adverse events. Results: According to the dichotomous analysis of sedation level (Ramsay score 1 and 2 versus Ramsay ≥ 3), oral association of S(+)-ketamine and midazolam improved sedation, with increased probability of Ramsay ≥ 3, Relative Risk (RR) = 3.2 (95% Confidence Interval [95% CI] = 1.32 to 7.76) compared to midazolam alone. Combined treatment also made it easier to obtain venous access without physical stabilization, RR = 2.05 (95% CI = 1.14 to 3.68). There were no differences between groups regarding awakening time and the occurrence of adverse events. Conclusion: The association of oral S(+)-ketamine with midazolam provides better preanesthetic sedation rates than midazolam alone and facilitates intravenous line access in patients with autism.

Residual unabsorbed midazolam: a case report.

BACKGROUND: Oral midazolam is commonly administered to reduce anxiety in children presenting for medical procedures or surgery. It is unclear what volume of medication remains unabsorbed in the stomach when the child presents for anesthetic induction prior to these procedures. The presence of any significant residual medication in the stomach has significant clinical implications in the postoperative period. CASE PRESENTATION: A 5-year-old white Caucasian boy presented for upper gastrointestinal endoscopy after receiving oral midazolam liquid. Insertion of the endoscope into the stomach revealed a significant amount of unabsorbed medication remaining within the gastric cavity. CONCLUSION: Clinicians should be aware that the sedative effects of midazolam may be present before the medication is fully absorbed. A significant amount of unabsorbed medication may be present in the stomach during medical procedures/surgery. This may continue to be absorbed in the intraoperative and postoperative period, with unwanted clinical effect.

Oral preanesthetic medication in children ... comparison between midazolam alone and in combination with ketamine: a systematic review and meta-analysis.

BACKGROUND: Up to 60% of pediatric surgical patients develop high levels of preoperative anxiety. This study compared the effects of oral combinations of midazolam and ketamine with oral midazolam alone for pediatric preanesthetic medication. METHODS: The study protocol was registered in PROSPERO as CRD42020172920. A systematic literature search was conducted using Medline, Cochrane, EMBASE, CENTRAL, and Web of Science for randomized controlled trials comparing oral combinations of midazolam and ketamine with midazolam alone as preanesthetic medication in elective surgical pediatric patients. Meta-analyses included the following outcomes: anxiety and sedation levels, child...s behavior during separation from parents, face mask acceptance, and venipuncture. The quality of evidence was assessed using GRADE criteria. RESULTS: Twenty studies were included. The following effects (RR (95% CI)) were observed for combinations of ketamine and midazolam relative midazolam alone: anxiolysis (1.2 (0.94...1.52); p.ß=.ß0.15; I2.ß=.ß80%; GRADE.ß=.ßvery low); satisfactory sedation (1.2 ( 1.10...1.31); p.ß<.ß0.001; I2.ß=.ß71%; GRADE.ß=.ßvery low); behavior during parental separation (1.2 (1.06...1.36); p.ß=.ß0.003; I2.ß=.ß88%; GRADE.ß=.ßvery low); facial mask acceptance (1.13 (1.04...1.24); p.ß=.ß0.007; I2.ß=.ß49%; GRADE.ß=.ßvery low); behavior during venipuncture (1.32 (1.11...1.57); p.ß=.ß0.002; I2.ß=.ß66%; GRADE.ß=.ßvery low). CONCLUSIONS: While similar probabilities of obtaining anxiolysis were found, adequate sedation, calm behavior during child...s separation from parents, low levels of fear during face mask adaptation, and cooperative behavior during peripheral venous cannulation were more likely with midazolam-ketamine combinations.

Comparison between oral midazolam versus oral ketamine plus midazolam as preanesthetic medication in autism spectrum disorder: double-blind randomized clinical trial.

BACKGROUND: Conventional dental care is often impossible in patients with Autism Spectrum Disorder (ASD). Non-collaborative behaviors, sometimes associated with aggressiveness, are usual justifications for premedication in this population. Thereby, this research focuses on the effects of oral midazolam versus oral ketamine plus midazolam as preanesthetic medication in ASD. METHODS: The sample included 64 persons with ASD, aged 2-59 years, scheduled for dental care under general anesthesia. The primary objective of this study was to compare degrees of sedation between two parallel, double-blinded, equally proportional groups randomized to receive oral midazolam (0.5 mg.kg-1, maximum 15 mg) or oral midazolam (0.5 mg.kg-1) associated with oral S(+)-ketamine (3 mg.kg-1, maximum 300 mg). The secondary outcomes were the need of physical stabilization to obtain intravenous line, awakening time, and occurrence of adverse events. RESULTS: According to the dichotomous analysis of sedation level (Ramsay score 1 and 2 versus Ramsay ≥ 3), oral association of S(+)-ketamine and midazolam improved sedation, with increased probability of Ramsay ≥ 3, Relative Risk (RR) = 3.2 (95% Confidence Interval [95% CI] = 1.32 to 7.76) compared to midazolam alone. Combined treatment also made it easier to obtain venous access without physical stabilization, RR = 2.05 (95% CI = 1.14 to 3.68). There were no differences between groups regarding awakening time and the occurrence of adverse events. CONCLUSION: The association of oral S(+)-ketamine with midazolam provides better preanesthetic sedation rates than midazolam alone and facilitates intravenous line access in patients with autism.

Oral preanesthetic medication in children - comparison between midazolam alone and in combination with ketamine: a systematic review and meta-analysis

Abstract Background Up to 60% of pediatric surgical patients develop high levels of preoperative anxiety. This study compared the effects of oral combinations of midazolam and ketamine with oral midazolam alone for pediatric preanesthetic medication. Methods The study protocol was registered in PROSPERO as CRD42020172920. A systematic literature search was conducted using Medline, Cochrane, EMBASE, CENTRAL, and Web of Science for randomized controlled trials comparing oral combinations of midazolam and ketamine with midazolam alone as preanesthetic medication in elective surgical pediatric patients. Meta-analyses included the following outcomes: anxiety and sedation levels, child's behavior during separation from parents, face mask acceptance, and venipuncture. The quality of evidence was assessed using GRADE criteria. Results Twenty studies were included. The following effects (RR (95% CI)) were observed for combinations of ketamine and midazolam relative midazolam alone: anxiolysis (1.2 (0.94-1.52); p= 0.15; I2 = 80%; GRADE = very low); satisfactory sedation (1.2 ( 1.10-1.31); p< 0.001; I2 = 71%; GRADE = very low); behavior during parental separation (1.2 (1.06-1.36); p= 0.003; I2 = 88%; GRADE = very low); facial mask acceptance (1.13 (1.04-1.24); p= 0.007; I2 = 49%; GRADE = very low); behavior during venipuncture (1.32 (1.11-1.57); p= 0.002; I2 = 66%; GRADE = very low). Conclusions While similar probabilities of obtaining anxiolysis were found, adequate sedation, calm behavior during child's separation from parents, low levels of fear during face mask adaptation, and cooperative behavior during peripheral venous cannulation were more likely with midazolam-ketamine combinations.

Serum concentration of oral midazolam as pediatric preanesthetic medication and factors related to the sedation level.

BACKGROUND: Preanesthetic medication is important to eliminate surgical anxiety in pediatric patients and facilitate their smooth transfer to the operating room. Midazolam is the most commonly used preanesthetic medication. However, it has been reported that the sedative effect varies from patient to patient. In this study, the pharmacokinetics of midazolam were examined, and the aim was to assess the factors affecting the quality of sedation. METHODS: The participants were children ranging in age from 6 months to 8 years scheduled for surgery. Midazolam 0.5 mg/kg was administered orally 30 min before entering the operating room, and the sedation level was evaluated at the time of mask application. Blood was collected after slow induction, and the serum concentration of midazolam was measured using high-performance liquid chromatography. RESULTS: A total of 98 patients were registered. There was no difference in serum concentrations between the effective sedation group and the ineffective sedation group (48.0 vs. 49.1 ng/mL), regardless of the effect of midazolam. Percentages of ineffective sedation by age (0 to 7 years) were 66.6%, 60%, 33.3%, 11.1%, 0%, 0%, 12.5%, and 0%, respectively. On multivariate logistic regression analysis, siblings (OR = 3.9, CI: 1.1-14.0, p = .03) and age (OR = 3.2, CI:1.2-8.5, p = .02) were related to an insufficient sedative effect. CONCLUSION: The serum concentration of oral midazolam reached effective levels even in patients in whom the sedative effect was inadequate. It is important to manage the perioperative period with appropriate concurrent premedication taking into account patient age and social background characteristics. CLINICAL TRIAL REGISTRATION: Clinical trial registry: UMIN R000052504.

Clonidine Versus Midazolam Premedication and Postoperative Negative Behavioral Changes in Younger Children: A Randomized Controlled Trial.

BACKGROUND: Postoperative negative behavioral changes (NBCs) are common among children, but risk for this is thought to be reduced with premedication. Midazolam has for many years been a standard premedication for children. More recently, the alpha-2 adrenergic agonist clonidine has also become popular as a preanesthetic sedative. We hypothesized that clonidine was superior to midazolam for limiting new NBCs in children as assessed using the Post Hospital Behavior Questionnaire (PHBQ). METHODS: This was a prospective, randomized, controlled, blinded study, including 115 participants aged 24 to 95 months and their parents. The participants underwent ear, nose, or throat outpatient surgery and were randomly allocated to premedication with oral midazolam 0.5 mg/kg or oral clonidine 4 µg/kg. Participants were anesthetized by protocol. At home, later, parents were asked to complete the PHBQ assessment instrument for postoperative NBCs for the participants 1 week, 1 month, and 6 months after the surgery. A secondary outcome, preinduction anxiety, was assessed using modified Yale Preoperative Anxiety Scale (mYPAS). RESULTS: The primary outcome, more than 3 NBCs in an individual case at 1 week, showed no difference in proportions between treatment in the clonidine group compared to the midazolam group, (12/59 or 20% vs 7/56 or 13%, respectively, odds ratio 1.39, 95% confidence interval [CI], 0.75-2.58; P = .32). A secondary result showed a higher preinduction anxiety level in the clonidine compared to the midazolam group (mYPAS >30, 43/59 or 71% vs 12/56 or 21%, respectively; P < .001). CONCLUSIONS: These results did not show a clinical or statistically significant difference, with respect to the primary outcome of behavior changes at 1 week, between the cohorts that received midazolam versus clonidine as a premedication.

Anestesia total intravenosa para tratamento endodôntico em Panthera leo ­ relato de caso / Total intravenous anesthesia for endodontic treatment in Panthera leo ­ case report

Animais presentes em zoológicos frequentemente necessitam de captura e anestesia para a realização de procedimentos clínicos e cirúrgicos. A anestesia total intravenosa apresenta vantagens como redução do estresse cirúrgico e menor depressão cardiovascular e respiratória. Entretanto, ainda são escassas as pesquisas dedicadas dentro deste contexto. Nesse sentido, o objetivo deste relato foi avaliar o protocolo anestésico empregado, visando um procedimento seguro e passível de reversão para a espécie silvestre selecionada. Acompanhou-se a anestesia de um leão (Panthera leo), macho, adulto, proveniente do Zoológico Municipal de Curitiba, submetido a procedimento endodôntico. A medicação pré-anestésica constituiu-se de dexmedetomidina (6 µg/kg), metadona (0,2 mg/kg), midazolam (0,1 mg/kg) e tiletamina-zolazepam (1,2 mg/kg). A indução foi realizada com propofol (1,5 mg/kg) e o animal foi intubado. Visando promover analgesia local, foi realizado bloqueio infraorbitário esquerdo com 5 mL de lidocaína a 2%. A manutenção foi realizada por meio do fornecimento de propofol (0,02-0,1 mg/kg/h), dexmedetomidina (0,5 µg/kg/h) e remifentanil (5 µg/kg/h). O paciente apresentou sedação profunda e foi mantido em plano anestésico cirúrgico; todos os parâmetros fisiológicos monitorados permaneceram estáveis durante todo o procedimento. Após 55 minutos de anestesia o paciente apresentava sustentação espontânea da cabeça, quando foi novamente transportado ao zoológico para soltura no recinto. A ambulação foi considerada normal pelos observadores no zoológico seis horas após a anestesia. Pôde-se concluir que o protocolo realizado se mostrou tanto eficaz quanto seguro para a referida espécie encaminhada ao procedimento em questão.

Zoo animals often require capture and anesthesia in order to undergo clinical and surgical procedures. Total intravenous anesthesia has advantages such as reduced surgical stress and less cardiovascular and respiratory depression. However, specific research on this matter is still scarce. Therefore, the present report aims to evaluate the anesthetic protocol employed, seeking a safe and reversible procedure for the selected wild species. A male adult lion (Panthera leo), from the Zoológico Municipal de Curitiba, was subjected to an endodontic anesthesia, under close monitoring. The pre-anesthetic medication consisted of dexmedetomidine (6 µg/kg), methadone (0.2 mg/kg), midazolam (0.1 mg/kg) and tiletamine-zolazepam (12 mg/kg). Induction was performed with propofol (1 mg/kg) and the animal was intubated. In order to promote local analgesia, a left infraorbital block was implemented with 5 mL of 2% lidocaine. Maintenance was undertaken by supplying propofol (0.02-0.1 mg/kg/min), dexmedetomidine (0.5 µg/kg/h) and remifentanil (5 µg/kg/h). The patient exhibited deep sedation and followed the surgical anesthetic plan; all the monitored physiological parameters remained stable throughout the procedure. After 55 minutes of anesthesia the patient showed spontaneous head support, when it was transported back to the zoo. The ambulation was considered normal by the zoo observers 6 hours after the anesthesia. It was concluded that the protocol was both effective and safe for the referred species undergone the procedure reported.

Preoperative anxiety in preschool children: A randomized clinical trial comparing midazolam, clonidine, and dexmedetomidine.

INTRODUCTION: Anxiety in pediatric patients may challenge perioperative anesthesiology management and worsen postoperative outcomes. Sedative drugs aimed to reducing anxiety are available with different pharmacologic profiles, and there is no consensus on their effect or the best option for preschool children. In this study, we aimed to compare the effect of three different premedications on anxiety before anesthesia induction in preschool children aged 2-6 years scheduled for elective surgery. The secondary outcomes comprised distress during peripheral catheter (PVC) insertion, compliance at anesthesia induction, and level of sedation. PATIENTS AND METHODS: In this double-blinded randomized clinical trial, we enrolled 90 participants aged 2-6 years, who were scheduled for elective ear-, nose-and-throat surgery. The participants were randomly assigned to three groups: those who were administered 0.5 mg/kg oral midazolam, 4 µg/kg oral clonidine, or 2 µg/kg intranasal dexmedetomidine. Anxiety, distress during PVC insertion, compliance with mask during preoxygenation, and sedation were measured using the modified Yale Preoperative Anxiety Scale, Behavioral Distress Scale, Induction Compliance Checklist, and Ramsay Sedation Scale, respectively. RESULTS: Six children who refused premedication were excluded, leaving 84 enrolled patients. At baseline, all groups had similar levels of preoperative anxiety and distress. During anesthesia preparation, anxiety was increased in the children who received clonidine and dexmedetomidine; however, it remained unaltered in the midazolam group. There were no differences in distress during PVC insertion or compliance at induction between the groups. The children in the clonidine and dexmedetomidine groups developed higher levels of sedation than those in the midazolam group. CONCLUSIONS: In preschool children, midazolam resulted in a more effective anxiolysis and less sedation compared to clonidine and dexmedetomidine.

Midazolam Premedication Immediately Before Surgery Is Not Associated With Early Postoperative Delirium.

BACKGROUND: Postoperative delirium is common among older surgical patients and may be associated with anesthetic management during the perioperative period. The aim of this study is to assess whether intravenous midazolam, a short-acting benzodiazepine used frequently as premedication, increased the incidence of postoperative delirium. METHODS: Analyses of existing data were conducted using a database created from 3 prospective studies in patients aged 65 years or older who underwent elective major noncardiac surgery. Postoperative delirium occurring on the first postoperative day was measured using the confusion assessment method. We assessed the association between the use or nonuse of premedication with midazolam and postoperative delirium using a χ2 test, using propensity scores to match up with 3 midazolam patients for each control patient who did not receive midazolam. RESULTS: A total of 1266 patients were included in this study. Intravenous midazolam was administered as premedication in 909 patients (72%), and 357 patients did not receive midazolam. Those who did and did not receive midazolam significantly differed in age, Charlson comorbidity scores, preoperative cognitive status, preoperative use of benzodiazepines, type of surgery, and year of surgery. Propensity score matching for these variables and American Society of Anesthesiology physical status scores resulted in propensity score-matched samples with 1-3 patients who used midazolam (N = 749) for each patient who did not receive midazolam (N = 357). After propensity score matching, all standardized differences in preoperative patient characteristics ranged from -0.07 to 0.06, indicating good balance on baseline variables between the 2 exposure groups. No association was found between premedication with midazolam and incident delirium on the morning of the first postoperative day in the matched dataset, with odds ratio (95% confidence interval) of 0.91 (0.65-1.29), P = .67. CONCLUSIONS: Premedication using midazolam was not associated with higher incidence of delirium on the first postoperative day in older patients undergoing major noncardiac surgery.

Preanesthetic nebulized ketamine vs preanesthetic oral ketamine for sedation and postoperative pain management in children for elective surgery: A retrospective analysis for effectiveness and safety.

ABSTRACT: Preoperative anxiety is a major problem in children leading to a poor outcome. Preanesthetic oral ketamine is generally used in children but has less bioavailability due to the first-pass effect. Even ketamine has an unpleasant taste. Preanesthetic inhaled ketamine is also reported effective and safe in children. The objectives of the study were to compare the effectiveness and safety of preanesthetic nebulized ketamine against preanesthetic oral ketamine for sedation and postoperative pain management in children.Children received 10 mg/kg oral ketamine (children received preanesthetic oral ketamine [OK cohort], n = 142), or nebulized with 3 mg/kg ketamine (children were preanesthetic nebulized with ketamine [NK cohort], n = 115), or received apple juice (children suspectable to preoperative ketamine and received apple juice only [OA cohort], n = 126) before anesthesia for elective surgery. Data regarding preoperative hemodynamic parameters, sedation score measurements, postoperative pain management, postoperative nausea and vomiting management, and postoperative complications were collected and analyzed.Preoperative hemodynamic parameters for oral and nebulized ketamine administration were stable. Nebulized ketamine was provided higher sedation than apple juice (P = .002, q = 4.859) and oral ketamine (P = .002, q = 3.526). Children of NK cohort had required fewer fentanyl consumption until discharge than those of OA (55.45 ±â€Š7.19 µG/ child vs 65.15 ±â€Š15.24 µG/ child, P < .0001, q = 9.859) and OK (55.45 ±â€Š7.19 µG/child vs 60.19 ±â€Š8.12 µG/child, P < .0001, q = 4.953) cohorts. Children of the NK cohort had consumed higher ondansetron syrup than those of the OA cohort but fewer than those of the OK cohort until discharge. Gastrointestinal side effects were reported in the OK cohort, and nose irritation and drowsiness were reported in the NK cohort.Like preanesthetic oral ketamine, preanesthetic inhaled ketamine also has safety for children. Preanesthetic inhaled ketamine can provide effective sedation in low doses during operation than preanesthetic oral ketamine.Level of evidence: III.

Modeling the Effect of Excitation on Depth of Anesthesia Monitoring in γ-Aminobutyric Acid Type A Receptor Agonist ABP-700.

BACKGROUND: γ-Aminobutyric acid type A (GABAA) receptor agonists are known to cause involuntary muscle movements. The mechanism of these movements is not known, and its relationship to depth of anesthesia monitoring is unclear. We have explored the effect of involuntary muscle movement on the pharmacokinetic-pharmacodynamic model for the GABAA receptor agonist ABP-700 and its effects on the Bispectral Index (BIS) as well as the Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scores. METHODS: Observations from 350 individuals (220 men, 130 women) were analyzed, comprising 6,312 ABP-700 concentrations, 5,658 ABP-700 metabolite (CPM-acid) concentrations, 25,745 filtered BIS values, and 6,249 MOAA/S scores, and a recirculatory model developed. Various subject covariates and pretreatment with an opioid or a benzodiazepine were explored as covariates. Relationships between BIS and MOAA/S models and involuntary muscle movements were examined. RESULTS: The final model shows that the pharmacokinetics of ABP-700 are characterized by small compartmental volumes and rapid clearance. The BIS model incorporates an effect-site for BIS suppression and a secondary excitatory/disinhibitory effect-site associated with a risk of involuntary muscle movements. The secondary effect-site has a threshold that decreases with age. The MOAA/S model did not show excitatory effects. CONCLUSIONS: The GABAA receptor agonist ABP-700 shows the expected suppressive effects for BIS and MOAA/S, but also disinhibitory effects for BIS associated with involuntary muscle movements and reduced by pretreatment. Our model provides information about involuntary muscle movements that may be useful to improve depth of anesthesia monitoring for GABAA receptor agonists.

Ketamine Enhances Intranasal Dexmedetomidine-Induced Sedation in Children: A Randomized, Double-Blind Trial.

PURPOSE: To compare the efficacy of intranasal dexmedetomidine and dexmedetomidine-ketamine premedication in preschool children undergoing tonsillectomy. PATIENTS AND METHODS: We enrolled 66 children with American Society of Anesthesiologists physical status I or II, aged 3-7 years undergoing tonsillectomy. Patients were randomly allocated to receive intranasal premedication with either dexmedetomidine 2 µg kg-1 (Group D) or dexmedetomidine 2 µg kg-1 and ketamine 2 mg kg-1 (Group DK). The primary outcome was the sedation level assessed by the Modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) 30 min after intervention. The minimal clinically relevant difference in the MOAA/S score was 0.5. Secondary outcomes included sedation onset time, parental separation anxiety, acceptance of mask induction, emergence time, emergence delirium, postoperative pain intensity, length of stay in the post-anesthesia care unit (PACU), and adverse effects. RESULTS: At 30 min after premedication, the MOAA/S score was lower in Group DK than in Group D patients (median: 1.0, interquartile range [IQR]: 1.0-2.0 vs median: 3.0, IQR: 2.0-3.0; P<0.001), with a median difference of 1.0 (95% confidence interval [CI]: 1.0-2.0, P<0.001). Patients in Group DK showed considerably faster onset of sedation (15 min, 95% CI: 14.2-15.8 min) than Group D (24 min, 95% CI: 23.2-24.8 min), with a median difference of 8.0 min (95% CI: 7.0-9.0 min, P<0.001). Both parental separation and facemask acceptance scores were lower in Group DK than in Group D patients (P=0.012 and P=0.001, respectively). There was no significant difference in emergence time, incidence of emergence delirium, postoperative pain scores, and length of stay in the PACU between the two groups. CONCLUSION: Intranasal premedication with a combination of dexmedetomidine and ketamine produced better sedation for pediatric tonsillectomy than dexmedetomidine alone.