Anesthetic management of a pediatric patient with Loeys-Dietz syndrome: A case report.

Loeys-Dietz syndrome, a rare autosomal dominant disease, is characterized by arterial tortuosity and skeletal manifestations. We report anesthetic management of scoliosis surgery for a pediatric Loeys-Dietz syndrome patient. During surgery, severe hypotension occurred when a rotation-correction was performed; blood pressure returned to the baseline level after the maneuver was abandoned. We decided to not conduct rotation correction after discussing risks and benefits of the maneuver with surgeons. Since severe hemodynamic instability is expected in scoliosis surgery for Loeys-Dietz syndrome patients, we should be prepare for hemodynamic collapse and risks and benefits of the operative procedure should be discussed before undertaking the procedure.

Comparison of the clinical performance of i-gel and Ambu AuraGain in children: A randomised noninferiority clinical trial.

BACKGROUND: Supraglottic airway devices are commonly used in general anaesthesia in children. The AuraGain is a newly developed disposable second-generation supraglottic airway device with an inflatable cuff and a gastric port. OBJECTIVE: To confirm our hypothesis that the oropharyngeal leak pressure (OLP) of the AuraGain would be noninferior to that of the i-gel in paediatric patients. DESIGN: A single-blinded, randomised, noninferiority, clinical trial. SETTING: Single-centre trial from January to March 2017. PATIENTS: One hundred paediatric patients (American Society of Anesthesiologists' physical status 1 to 3), aged up to 12 years old, and body weight of 5 to 30 kg requiring a supraglottic airway for elective surgery with an expected surgery time of less than 2 h under general anaesthesia. INTERVENTION: The patients were randomised to allocation to the AuraGain group or the i-gel group. The device size (1.5 to 2.5) used in each group was based on the manufacturer's recommendation. MAIN OUTCOME MEASURES: The primary outcome measure was OLP immediately after insertion, with a predefined noninferiority margin of 3 cmH2O. RESULTS: The OLP immediately after insertion was lower for the AuraGain than for the i-gel (17.1 vs. 23.0 cmH2O; mean difference: -5.9 cmH2O; 95% confidence interval: -8.5 to -3.3 cmH2O; P = 0.98 and <0.001 for noninferiority and superiority, respectively). The first-attempt success rate (AuraGain, 96% vs. i-gel, 90%; P = 0.44) was comparable between the devices. The incidence of blood staining was lower (AuraGain, 6% vs. i-gel, 0%; P = 0.012) and time to insertion was shorter (AuraGain 21.3 vs. i-gel, 17.1 s; P < 0.001) for the i-gel compared with the AuraGain. CONCLUSION: Our noninferiority hypothesis was not adopted. The OLP of the i-gel may be higher than that of the AuraGain, but this superiority hypothesis should be investigated in future trials. The i-gel demonstrated a shorter time to successful placement and lower incidence of blood staining than the AuraGain. TRIAL REGISTRATION: University Hospital Medical Information Network identifier, UMIN000024222.

Predictors for incidence of increased time spent in hospital after ambulatory surgery in children: a retrospective cohort study.

PURPOSE: Recently, pediatric ambulatory surgery has become common. However, for some of these patients, unplanned admission or prolonged hospital stay is also necessary, which can increase the mental burden on these patients. The aim of this study was to identify the predictors of the incidence of increased time spent in hospitals associated with pediatric ambulatory surgery. METHODS: Data were obtained from the medical and anesthetic records of 1087 consecutive patients aged < 18 years who underwent ambulatory surgery under general anesthesia. We defined the incidence of increased time spent in a hospital as a composite outcome of unplanned admission and prolonged hospital stay. Multivariate logistic regression analysis was used to examine the associations between the incidence of increased time spent in a hospital and 14 parameters including patient characteristics, anesthesia, and operative factors. RESULTS: Multivariate analysis identified American Society of Anesthesiologist Physical Status (ASA-PS), type of regional block, intraoperative fluid volume, and type of surgery as predictors for the incidence of increased time spent in a hospital. Specifically, caudal block compared to no regional block [odds ratio (OR) (95% confidence interval (CI)) = 0.44 (0.22-0.90)]; increasing intraoperative fluid volume [OR (95% CI) = 0.71 (0.55-0.92) in every increment of 5 ml/kg/h); and ear, nose, and throat (ENT) and urology surgery compared to other types of surgery [OR (95% CI) = 0.13 (0.03-0.64), and 3.93 (1.99-7.77), respectively] were identified as strong predictors. CONCLUSIONS: This study found that the incidence of increased time spent in a hospital in pediatric ambulatory surgery was affected by the type of regional block, intraoperative fluid volume, type of surgery. Potentially modifiable factors, such as intraoperative fluid volume or type of regional block, should be further investigated in future prospective studies.

Effect of an Intravenous Dexamethasone Added to Caudal Local Anesthetics to Improve Postoperative Pain: A Systematic Review and Meta-analysis With Trial Sequential Analysis.

BACKGROUND: Caudal anesthesia has been used for postoperative pain control in pediatric surgical patients, but the duration of the analgesic effect is occasionally unsatisfactory. Intravenous steroids have been shown to be effective for postsurgical pain management after certain surgeries. The aim of this meta-analysis with trial sequential analysis (TSA) was to evaluate the analgesic effect of steroids in patients administered with caudal anesthesia. METHODS: This study was a systematic review and meta-analysis. A search of published literature was conducted in the MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled Trials databases and in trial registration sites. Randomized controlled trials that compared intravenous steroids with a placebo in pediatric patients who had received caudal anesthesia for surgery were included in the study. The primary outcomes from the present meta-analysis were the analgesic duration and the number of patients who required rescue analgesics. The analgesic duration and incidence of rescue use were summarized using mean difference or risk ratio with a 97.5% confidence interval (CI), respectively. If the 97.5% CI of the mean difference or risk ratio included a value of 0 or 1, respectively, we considered the difference not to be significant. We used the random effects model to combine the results. Heterogeneity was quantified with the I statistic. The quality of the trials was evaluated using the Cochrane methodology. Moreover, a TSA with a risk of type 1 error of 2.5% and power of 90% was performed. We established the minimum clinically meaningful difference of analgesic duration as 3 hours. The target sample size for meta-analysis was also calculated in the TSA. We also assessed adverse events. RESULTS: Six trials with 424 patients were included; 211 patients received intravenous steroids. All trials compared dexamethasone of at least 0.5 mg/kg dose with a placebo. Dexamethasone prolonged the duration of caudal analgesia (mean difference, 244 minutes; 97.5% CI, 188-300). Heterogeneity was considerable with an I value of 94.8%. Quality of evidence was very low. The TSA suggested that only 17.0% of the target sample size had been reached, but the cumulative Z score crossed the trial sequential monitoring boundary to indicate a benefit. Rescue use was reported in 4 studies with 260 patients. Rescue use was not significantly reduced in the dexamethasone group (risk ratio, 0.53; 97.5% CI, 0.09-3.30; I, 98.7%). No increase in adverse events was reported. CONCLUSIONS: Intravenous dexamethasone prolongs the analgesic duration of caudal anesthesia. Trials to investigate the effectiveness of a lower dose of the dexamethasone in prolonging analgesic effects would be of interest. Further trials with a low risk of bias are necessary.

Development and Validation of a Risk Scale for Emergence Agitation After General Anesthesia in Children: A Prospective Observational Study.

BACKGROUND: Emergence agitation (EA) is a common complication in children after general anesthesia. The goal of this 2-phase study was (1) to develop a predictive model (EA risk scale) for the incidence of EA in children receiving sevoflurane anesthesia by performing a retrospective analysis of data from our previous study (phase 1) and (2) to determine the validity of the EA risk scale in a prospective observational cohort study (phase 2). METHODS: Using data collected from 120 patients in our previous study, logistic regression analysis was used to predict the incidence of EA in phase 1. The optimal combination of the predictors was determined by a stepwise selection procedure using Akaike information criterion. The ß-coefficient for the selected predictors was calculated, and scores for predictors determined. The predictive ability of the EA risk scale was assessed by a receiver operating characteristic (ROC) curve, and the area under the ROC curve (c-index) was calculated with a 95% confidence interval (CI). In phase 2, the validity of the EA risk scale was confirmed using another data set of 100 patients (who underwent minor surgery under general anesthesia). The ROC curve, the c-index, the best cutoff point, and the sensitivity and specificity at the point were calculated. In addition, we calculated the gray zone, which ranges between the two points where sensitivity and specificity, respectively, become 90%. RESULTS: In phase 1, the final model of the multivariable logistic regression analysis included the following 4 predictors: age (logarithm odds ratios [OR], -0.38; 95% CI, -0.81 to 0.00), Pediatric Anesthesia Behavior score (logarithm OR, 0.65; 95% CI, -0.09 to 1.40), anesthesia time (logarithm OR, 0.60; 95% CI, -0.18 to 1.19), and operative procedure (logarithm OR, 2.53; 95% CI, 1.30-3.75 for strabismus surgery and logarithm OR, 2.71; 95% CI, 0.99-4.45 for tonsillectomy). The EA risk scale included these 4 predictors and ranged from 1 to 23 points. In phase 2, the incidence of EA was 39%. The c-index of phase 1 was 0.84 (95% CI, 0.74-0.94), and the c-index of phase 2 was 0.81 (95% CI, 0.72-0.89). The best cutoff point for the EA risk scale was 11 (sensitivity = 87% and specificity = 61%). The gray zone ranged from 10 to 13 points, and included 38% of patients. CONCLUSIONS: We developed and validated an EA risk scale for children receiving sevoflurane anesthesia. In our validation cohort, this scale has excellent predictive performance (c-index > 0.8). The EA risk scale could be used to predict EA in children and adopt a preventive strategy for those at high risk. This score-based preventive approach should be studied prospectively to assess the safety and efficacy of such a strategy.

Electrical stimulation of the heart 7 acupuncture site for preventing emergence agitation in children: A randomised controlled trial.

BACKGROUND: Emergence agitation is common in children recovering from general anaesthesia. The prevention of emergence agitation remains an important challenge in the field of paediatric anaesthesia. OBJECTIVE: We aimed to examine the effectiveness of electrically stimulating the heart 7 (HT7) acupuncture site with a peripheral nerve stimulator (PNS) during surgery, for preventing emergence agitation in paediatric patients recovering from general anaesthesia. DESIGN: A double-blind, randomised, controlled, parallel-group trial. SETTING: Kanagawa Children's Medical Centre, Yokohama, Japan. PATIENTS: One hundred and twenty patients aged 18 to 96 months (American Society of Anesthesiologists physical status I or II) undergoing minor elective surgery under general anaesthesia with sevoflurane. INTERVENTION: Patients were randomly assigned to either undergo bilateral stimulation of HT7 with two PNS devices (1 Hz, 50 mA) during surgery (Group HT7) or a control group that did not undergo electrical stimulation of HT7 during surgery. MAIN OUTCOME MEASURES: The primary outcome was the incidence of emergence agitation evaluated in the postanaesthesia care unit (PACU) using the Paediatric Anaesthesia Emergence Delirium scale. The secondary outcomes were the time from operation completion to tracheal extubation, PACU stay duration and postoperative pain scores. RESULTS: The incidence of emergence agitation was significantly lower in the HT7 group compared with the control group (31.7 vs. 56.7%, respectively; P = 0.010). The risk ratio was 0.56 (95% confidence interval 0.36 to 0.86) and the number needed to treat was 4 (95% confidence interval 3 to 13). There were no statistically significant differences between groups in time from operation completion to tracheal extubation, PACU stay duration or postoperative pain. CONCLUSION: Bilateral electrical stimulation of HT7 using two PNS devices significantly decreases the incidence of emergence agitation. TRIAL REGISTRATION: UMIN Clinical Trial Registry (registry number: UMIN000011704).

The association of hypotension with the insertion of an abdominal retractor during lower abdominal surgery in pediatric patients: a retrospective observational study.

BACKGROUND: The Alexis(®) wound retractor is composed of an inner- and outer-ring, with the inner-ring placed inside the abdominal cavity. This placement can constrict the internal organs and large vessels, especially in children, which can lead to hypotension. Our study aimed to investigate the relation between the incidence of hypotension and insertion of the wound retractor during lower abdominal surgery in pediatric patients. METHODS: We retrospectively examined 161 pediatric patients (<4 years old), who underwent lower abdominal surgery, regardless of abdominal retractor type. Hypotension was defined as a decrease in systolic blood pressure of >15% from baseline. We used logistic regression to predict hypotension using the following nine parameters: age, height, weight, American Society of Anesthesiologists physical status (ASA-PS), sex, laterality of the operation (unilateral or bilateral), presence or absence of caudal block, wound length, and type of retractor (retractors with or without an inner-ring). RESULTS: Logistic multivariate regression analysis revealed that a retractor with an inner-ring use (odds ratio 3.28, 95% CI 1.41-7.63, P = 0.006) and younger age (odds ratio 1.07 per month, 95% CI 1.02-1.12, P = 0.010) were independent risk factors associated with hypotension following lower abdominal surgery in this age group. CONCLUSIONS: Patient age and use of a wound retractor with an inner-ring are independent risk factors associated with hypotension during insertion of the abdominal retractor in lower abdominal surgery.

Effects of melatonin premedication to prevent emergence agitation after general anaesthesia in children: A systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: Emergence agitation is a common phenomenon in children recovering from general anaesthesia. An emergence agitation reaction increases the risk of injuring the surgical repair, the patient and the caregivers. OBJECTIVE: The objective of this study is to examine the efficacy of melatonin premedication in emergence agitation prevention. DESIGN: A systematic review and meta-analysis of randomised controlled trials (RCTs) with trial sequential analysis (TSA) and meta-regression analysis. DATA SOURCES: We searched MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, Web of Science, clinicaltrials.gov and UMIN Clinical Trials Registry up to 4 April 2014. ELIGIBILITY CRITERIA: RCTs reporting effects of melatonin on the incidence of emergence agitation in children who underwent general anaesthesia were included. RESULTS: Four studies (358 participants) were analysed. A conventional random-effects meta-analysis showed that compared with placebo, melatonin premedication may be effective in emergence agitation prevention [risk ratio 0.31, 95% confidence interval (CI) 0.16 to 0.60; I2 = 0%]. However, TSA corrected the 95% CI to 0.07 to 1.47 and showed that 22.5% of the required information size (RIS) was achieved. The effect of melatonin compared with that of midazolam was not statistically significant (risk ratio 0.48, 95% CI 0.15 to 1.52) with significant heterogeneity (I2 = 36.8%). TSA-adjusted 95% CI could not be calculated because of the small information size (4% of RIS). Meta-regression showed that, compared with midazolam, melatonin dose was significantly correlated with the effect (P = 0.024). The risk ratios (95% CI) of low and high-dose melatonin were 1.02 (0.39 to 2.65) and 0.22 (0.08 to 0.58), respectively. There was no effect of melatonin compared with dexmedetomidine (risk ratio 1.0, 95% CI 0.15 to 6.55). TSA-adjusted 95% CI could not be calculated (0.9% of RIS). CONCLUSION: Compared with placebo, melatonin premedication may be effective in preventing emergence agitation in children (GRADE: low). This TSA suggests that further studies are required to confirm the results. Compared with midazolam, high-dose melatonin might have a significant effect in preventing emergence agitation (GRADE: very low). The study protocol was registered in the UMIN Clinical Trials Registry (registration number: UMIN000011841).

Anesthetic management of pediatric patients with Emanuel syndrome.

Emanuel syndrome is a rare anomaly associated with multiple systemic malformations. We present two cases involving pediatric patients with Emanuel syndrome. The first patient presented with micrognathia and had patent ductus arteriosus and a single kidney. The patient was difficult to intubate with McGRATH(®) but was successfully intubated with an Airtraq(®) device. The second patient did not present with micrognathia and was not difficult to intubate. A thorough examination of the heart, kidney, and spinal cord is important when planning the anesthetic management of patients with Emanuel syndrome. Moreover, adequate preparation for a difficult airway is essential, and the Airtraq(®) device may be useful for intubating patients with Emanuel syndrome with micrognathia.

[Airway management in children with vallecular cyst: review of 25 cases--can we predict difficult intubation?].

BACKGROUND: Vallecular cysts frequently cause difficult intubation due to poor glottic visualization during direct laryngoscopy. The appropriate way of airway management and predictive factors of difficult intubation are unknown. METHODS: We reviewed anesthetic induction and airway management in 25 cases of vallecular cysts for the past 11 years. We collected the following data of 24 cases in 20 children who were intubated under direct laryngoscopy: age (month), height (cm), weight (kg), cyst-diameter (mm), cyst-diameter to patient-height ratio, and clinical symptoms. These data were compared between difficult intubation group (group A) and easy or slightly difficult intubation group (group B). RESULTS: In the majority of cases, anesthesia was induced with spontaneous ventilation maintained. Group A and B consisted of 6 and 18 cases, respectively. All cases of group A required assistive devices such as stylets or tube introducers. Cyst-diameter to patient-height ratios were significantly higher in group A than in group B (0.26 vs. 0.18, P = 0.03). CONCLUSIONS: Because children with vallecular cysts have a risk of difficult airway, we need to prepare for difficult airway management. The cyst-diameter to patient-height ratio could be useful as a predictor of difficult intubation.

[Preoperative assessment of children with fever and common cold: to proceed, or not to proceed, that is the question].

Fever and upper respiratory tract infections (URI) are frequently-encountered preoperative comorbidities. Whether or not to proceed with anesthesia for a child with common cold is still a continuing dilemma for anesthesiologists. We, anesthesiologists often feel uncomfortable in making a decision whether or not to proceed because URI is associated with perioperative respiratory adverse events (PRAEs) and there are no definite rules to proceed with or postpone a case. Most of PRAEs are easily managed by experienced hands; however, laryngospasm or bronchospasm without early detection and immediate treatment would probably result in serious sequelae. Although several factors (e. g., asthma, infancy, endotracheal intubation, airway surgery, parental smoking, and parental confirmation of a URI, etc.) related to PRAEs have been elucidated to date, no one can guess correctly which child will suffer from adverse events. Moreover, because children per se are vulnerable to PRAEs, we cannot reduce the risk to zero even without a URI. Therefore, we should be familiarized with how to cope with PRAEs. In making a decision to proceed with or postpone the case, it is important to take various factors together into account, and the decision ultimately depends on whether or not we feel "Yes, we can".

Anesthetic management of a child with Aicardi syndrome undergoing laparoscopic Nissen's fundoplication: a case report.

Aicardi syndrome (AS) is a rare congenital syndrome and is characterized by the triad of infantile spasm, agenesis of the corpus callosum, and anomaly of chorioretinal lacunae. We here report a case of a patient with AS under general anesthesia. Although there is no report in which muscle relaxants were used in AS patients, vecuronium bromide was used for artificial pneumoperitoneum in this case. Careful management is important for AS patients during an operation that significantly affects respiratory function. In addition, it is possible that muscle relaxants be administered safely in AS patients. Careful monitoring such as epileptiform electroencephalogram and bispectral index monitors may be needed for the early detection of epileptic activities.

[Anesthetic management in a patient with trifunctional protein deficiency].

A 4-year-old girl with trifunctional protein deficiency was scheduled for gastrostomy. She had recurrent episodes of rhabdomyolysis triggered by fasting, infection, stress and uncertain causes. In the management of anesthesia, we avoided both propofol and inhalational anesthetics and anesthetized her with benzodiazepine and opioid combined with regional anesthesia to minimize the stress response. Her metabolism was kept stable throughout the intraoperative period. However, on the second postoperative day, she developed rhabdomyolysis and was treated with glucose containing infusion. This case provides instructive information that strict management is needed for patients with trifunctional protein deficiency in the perioperative period.

Preventive effect of ramelteon on emergence agitation after general anaesthesia in paediatric patients undergoing tonsillectomy: a randomised, placebo-controlled clinical trial.

Purpose of this prospective, double-blind, parallel-group, placebo-controlled, randomised clinical trial was to confirm our hypothesis that ramelteon has a preventive effect on emergence agitation after general anaesthesia in children. Patients aged 18 to 119 months (ASA physical status 1 or 2), scheduled to undergo tonsillectomy under general anaesthesia, were randomly allocated to the ramelteon or placebo group. Before general anaesthesia induction, patients in the ramelteon group received 0.1 mg kg-1 of ramelteon dissolved in 5 mL of lactose-containing syrup. The patients in the placebo group received the same amount of syrup alone. The Paediatric Anaesthesia Emergence Delirium score was calculated every 5 min after awakening. The primary outcome was the incidence of emergence agitation (Paediatric Anaesthesia Emergence Delirium score ≥ 10). Paediatric Anaesthesia Emergence Delirium scores, post-operative vomiting incidence, pain scores, and adverse events were secondary outcomes. Fifty patients were enrolled. Forty-eight patients were analysed. There was no significant between-group difference in the incidence of emergence agitation (67% in both groups; risk ratio, 1.0; 95% CI 0.67-1.49; P > 0.99) or any of the secondary outcomes. Our results suggest that 0.1 mg kg-1 of ramelteon does not have a preventive effect on emergence agitation after general anaesthesia in children undergoing tonsillectomy.

[Anesthetic management for laryngoscopic evaluation of upper airway stenosis using our modified endoscopic mask].

Young children are at increased risk for hypoxaemia and hypercapnea during flexible laryngoscopy due to the small size and increased collapsibility of their airways. To evaluate upper airway stenosis of a 5-year-old girl presenting with retractive inspiratory breathing, we developed a modified endoscopy mask consisting of a regular face mask where the original port for endoscope was replaced by a disposable rubber dam. This setting allows a leak-free passage of both nasal and oral endoscopy and enables emergent endoscopic intubation through a small hole of a rubber dam. Using this airtightly sealed modified mask, we successfully managed diagnostic endoscopy of laryngomalacia and evaluated infolding of arytenoids under spontaneous ventilation with 100% oxygen.

Effect of magnesium added to local anesthetics for caudal anesthesia on postoperative pain in pediatric surgical patients: A systematic review and meta-analysis with Trial Sequential Analysis.

BACKGROUND: Magnesium has been investigated as an adjuvant for neuraxial anesthesia, but the effect of caudal magnesium on postoperative pain is inconsistent. The aim of this systematic review and meta-analysis was to evaluate the analgesic effect of caudal magnesium. METHODS: We searched six databases, including trial registration sites. Randomized clinical trials reporting the effect of caudal magnesium on postoperative pain after general anesthesia were eligible. The risk ratio for use of rescue analgesics after surgery was combined using a random-effects model. We also assessed adverse events. The I2 statistic was used to assess heterogeneity. We assessed risk of bias with Cochrane domains. We controlled type I and II errors due to sparse data and repetitive testing with Trial Sequential Analysis. We assessed the quality of evidence with GRADE. RESULTS: Four randomized controlled trials (247 patients) evaluated the need for rescue analgesics. In all four trials, 50 mg of magnesium was administered with caudal ropivacaine. The results suggested that the need for rescue analgesia was reduced significantly by caudal magnesium administration (risk ratio 0.45; 95% confidence interval 0.24-0.86). There was considerable heterogeneity as indicated by an I2 value of 62.5%. The Trial Sequential Analysis-adjusted confidence interval was 0.04-5.55, indicating that further trials are required. The quality of evidence was very low. The rate of adverse events was comparable between treatment groups. CONCLUSION: Caudal magnesium may reduce the need for rescue analgesia after surgery, but further randomized clinical trials with a low risk of bias and a low risk of random errors are necessary to assess the effect of caudal magnesium on postoperative pain and adverse events. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry UMIN000025344.

Unilateral electrical stimulation of the heart 7 acupuncture point to prevent emergence agitation in children: A prospective, double-blinded, randomized clinical trial.

BACKGROUND: Emergence agitation (EA) is a frequent phenomenon in children recovering from general anaesthesia and increases the risk of self-injury. Previously, our group reported that stimulating the heart 7 (HT7) acupuncture point bilaterally using two neuromuscular transmission monitoring devices (NTMs) decreased the incidence of EA. However, bilateral stimulation is a barrier to clinical use because two NTMs are needed for one patient. OBJECTIVE: The objective of this study was to examine the efficacy of unilateral electrical stimulation of HT7 using an NTM to prevent EA in children. DESIGN: Prospective, double-blinded, randomized clinical trial. SETTING: Kanagawa Children's Medical Centre, Yokohama, Japan. PATIENTS: One hundred children (ages 18-96 months) with ASA-PS I or II, who were scheduled to undergo inguinal hernia repair or orchiopexy under sevoflurane anaesthesia. INTERVENTION: Patients were randomly assigned to one of the following two groups: (1) HT7 group: unilateral (right side) stimulation of the HT7 acupuncture point using a single-twitch electrical stimulus (1 Hz, 50 mA) throughout the surgery, and (2) control group: electrodes alone were attached to the HT7 point on the right side; an electrical stimulus was not applied. MAIN OUTCOME MEASURES: The primary outcome was the incidence of EA evaluated using the pediatric anaesthesia emergence delirium (PAED) scale. The secondary outcomes were the incidence of EA evaluated using Aono's scale, the severity of EA, PACU stay duration, and postoperative pain. RESULTS: There was no statistical difference between the incidence of EA in the HT7 and the control group (28.0% and 24.0%, respectively; P > 0.99). The risk ratio was 1.17 (95% confidence interval: 0.60-2.27). CONCLUSIONS: We observed that there was no effect of unilateral single-twitch electrical stimulation to the HT7 on the incidence of EA, contrary to the findings with bilateral HT7 stimulation.