Factors affecting determination of the optimal ketamine dose for pediatric sedation

OBJECTIVE: Children are sedated before undergoing diagnostic imaging tests in emergency medicine or pediatric sedation anesthesia units. The aim of this study was to identify variables potentially affecting the dose of ketamine required for induction of sedation in pediatric patients undergoing diagnostic imaging.METHODS: This retrospective study included children aged 0 to 18 years who underwent sedation with ketamine for computed tomography or magnetic resonance imaging in the pediatric sedation anesthesia unit of a tertiary medical center between January 2011 and August 2016. The children’s hemodynamic status and depth of sedation were monitored during the examination. We recorded data on demographics, categories of imaging tests, ketamine doses administered, adverse events, respiratory interventions, and duration of sedation. Data for patients who experienced adverse events were excluded.RESULTS: Sixty-six patients were included in the final analysis. Univariate linear regression analysis revealed that patient age, height, and body surface area (BSA) affected the sedative dose of ketamine administered. These three variables showed multicollinearity in multivariate linear regression analysis and were analyzed in three separate models. The model with the highest adjusted R-squared value suggested the following equation for determination of the dose of ketamine required to induce sedation: ketamine dose (mg)=-1.62+0.7×age (months)+36.36×BSA (m²).CONCLUSION: Variables such as age and BSA should be considered when estimating the dose of ketamine required for induction of sedation in pediatric patients.

Safety and Efficacy of Off-label and Unlicensed Medicines in Children

BACKGROUND: The aim of this study was to explore the use of off-label/unlicensed drugs to confirm the safety and efficacy of their prescription in children in Korea. METHODS: In this retrospective study, we analyzed data of patients who received any of the 32 drugs between January–December 2014 in tertiary hospitals in Korea, including demographics, diagnoses, reasons for the medication, administration route, and details of adverse drug reactions. Additionally, the mortality in the cohort was assessed. The primary outcomes were efficacy and safety, including mortality, of these drugs in pediatric patients. The secondary outcomes were the current statuses of the use of off-label/unlicensed drugs in two centers. RESULTS: Totally, 5,130 prescriptions were found in 2,779 patients. Age (73.5%) and indication (11.7%) were the most frequent reasons for prescriptions being off-labeled/unlicensed. Approximately 88% of the prescriptions were effective, and 19% of the patients developed adverse drug reactions. The number of prescriptions was significantly higher in children with adverse drug reactions than it was in those without (2.8 vs. 1.5; P < 0.001). The number of prescribed off-label/unlicensed medicines and age at prescription were independently associated with adverse drug events (odds ratio, 1.55 and 1.1; P < 0.001 and 0.034, respectively). CONCLUSION: Children are still prescribed medicines that are not authorized in terms of age, weight, indications, or routes of administration. Therefore, many old products require re-assessment of authorization. More prospective clinical studies should be performed to confirm the efficacy and safety of drugs in the pediatric population.

A Simulation Study of Propofol Effect-Site Concentration for Appropriate Sedation in Pediatric Patients Undergoing Brain MRI: Pharmacodynamic Analysis

PURPOSE: We aimed to establish the propofol effect-site concentration (Ce) for appropriate sedation by pharmacodynamic analysis and to determine the propofol Ce during occurrence of sedation-related side effects in pediatric patients undergoing brain magnetic resonance imaging (MRI). MATERIALS AND METHODS: In 50 pediatric patients scheduled for brain MRI, sedation was induced with 2.0 mg/kg propofol; additional propofol doses were 0.5–1 mg/kg. Propofol Ce was simulated by inputting the propofol administration profiles of patients into a pediatric compartmental model (Choi model). The relationship between propofol Ce and probabilities of sedation and recovery were analyzed using a sigmoidal Emax model. The simulated propofol Ce for sedation-related side effects was investigated. Population model parameters were estimated using the Nonlinear Mixed-Effects Modelling software. RESULTS: The mean values of propofol Ce₅₀ for sedation during the preparation, scanning, and recovery phases were 1.23, 0.43, and 0.39 µg/mL. The simulated propofol Ce values during oxygen desaturation (SpO₂<90%) (3 patients; 6%), hypotension (16 patients; 32%), and bradycardia (12 patients; 24%) were 3.01±0.04, 2.05±0.63, and 2.41±0.89 µg/mL, respectively. CONCLUSION: The required propofol Ce₅₀ for applying monitors during the preparation phase before the start of MRI was higher than the propofol Ce₅₀ required during the scanning phase. During low-intensity stimulation phases, such as scanning, propofol bolus dose should be strictly titrated not to exceed the propofol Ce that can lead to oxygen desaturation because of the relatively low propofol Ce (Ce₉₅, 1.43 µg/mL) required for sedation in most patients.

The effect of electromagnetic guidance system on early learning curve of ultrasound for novices / 대한마취과학회지

BACKGROUND: Electromagnetic guidance reveals needle alignment and position relative to the image plane on an ultrasound view. This study compared the early learning curves of novices performing ultrasound-guided needle placement with (n = 10) or without electromagnetic guidance (n = 10). METHODS: Participants performed 30 ultrasound-guided needle placements using an echogenic stick (0.3-cm diameter) as a target inside a phantom model; this early learning period was divided into sequential periods (P1: 1-5, P2: 6-10, P3: 11-15, P4: 16-20, P5: 21-25, P6: 26-30 attempts). RESULTS: Using an in-plane approach, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in P1, P2, P4, and P6 and the number of needle advances of the EMG group was significantly smaller than that of the non-EMG group in P1 and P2. Using an out-of-plane approaches, the time required for needle placement in the EMG group was significantly shorter than that of the non-EMG group in all periods, but the number of needle advances was similar between both groups in P1-P5. CONCLUSIONS: The electromagnetic guidance system may be beneficial when performing ultrasound guided peripheral nerve blocks or vascular cannulation in the early learning period, especially by inexperienced operators with reducing patient risk.

Comparison between Glidescope and Lightwand for tracheal intubation in patients with a simulated difficult airway / 대한마취과학회지

BACKGROUND: Although Lightwand and Glidescope have both shown high success rates for intubation, there has been no confirmation as to which device is most effective for difficult endotracheal intubation. We compared the Glidescope and Lightwand devices in terms of duration of intubation and success rate at the first attempt in a simulated difficult airway situation. METHODS: Fifty-eight patients were randomized to undergo tracheal intubation with either the Glidescope (Glidescope group, n = 29) or the Lightwand (Lightwand group, n = 29). All patients were fitted with a semi-hard cervical collar in order to simulate a difficult airway, and intubation was attempted with the assigned airway device. The data collected included the rate of successful endotracheal intubation, the number of attempts required, the duration of the intubation, as well as the interincisor distance, hemodynamic variables, and adverse effects. RESULTS: There was no difference between Glidescope group (92.6%) and Lightwand group (96.4%) in terms of success rate for the first attempt at intubation. The duration of successful intubation for the first tracheal intubation attempt was significantly longer in Glidescope group than in Lightwand group (46.9 sec vs 29.5 sec, P = 0.001). All intubations were completed successfully within two intubation attempts. The incidence of hypertension was significantly higher in Glidescope group than in Lightwand group (51.9% vs 17.9%, P = 0.008). CONCLUSIONS: In a simulated difficult airway situation, endotracheal intubation using Lightwand yielded a shorter duration of intubation and lower incidence of hypertension than when using Glidescope.

Comparison of the preventive effects of pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine on propofol-LCT/MCT injection pain / 대한마취과학회지

BACKGROUND: Lidocaine has been used widely to prevent propofol injection pain. Various methods of administration exist, such as lidocaine premixed with propofol or lidocaine pretreatment using a tourniquet, but it is unclear which method of lidocaine administration is more effective for the prevention of injection pain of propofol LCT/MCT. The purpose of this study was to compare pretreatment of lidocaine with a tourniquet and a premixed injection of lidocaine to prevent injection pain of propofol-LCT/MCT. METHODS: Patients were randomly allocated into the pretreatment group (n = 117) or the premixed group (n = 117). The pretreatment group was pretreated with 2 ml of lidocaine 2%, held with a tourniquet, before propofol-LCT/MCT injection. The premixed group was injected with a premixed solution of propofol-LCT/MCT and 2 ml of lidocaine 2%. To evaluate the incidence and severity of pain, spontaneous verbal expressions of pain, movement of hand, frowning, and moaning were recorded, and the patients were asked to recall their pain with the visual analogue score (VAS) 30 minutes after awakening from anesthesia. RESULTS: Overall, injection pain occurred in 13.7% of the pretreatment group and 15.4% of the premixed group, without any statistical difference (P = 0.71). There was no difference in spontaneous verbal expressions of pain, movement of hand, frowning, and moaning between the two groups. The pain intensity (VAS) also showed no difference between the two groups (P = 0.49). CONCLUSIONS: Pretreatment of lidocaine with a tourniquet showed no more benefit to prevent injection pain of propofol LCT/MCT compared to a premixed injection with lidocaine.

Complete obstruction of an endotracheal tube due to an unexpected blood clot in a patient with a hemo-pneumothorax after repositioning of the patient for lumbar spine surgery / 대한마취과학회지

No abstract available.

Clinical experience of one lung ventilation using an endobronchial blocker in a patient with permanent tracheostomy after total laryngectomy / 대한마취과학회지

No abstract available.

The comparison of QTc interval change on the ECG during laparoscopic cholecystectomy under inhalation and total intravenous anesthesia

BACKGROUND: There can be changes in the cardiac function during laparoscopic cholecystectomy. In this study, QTc interval changes were compared between total intravenous anesthesia (TIVA) group and inhalation anesthesia group during laparoscopic cholecystectomy. METHODS: The study was conducted on adult patients, ages ranging from 20 to 65 years old, and classified as the American Society of Anesthesiologists physical status I or II. At random, the patients were divided into group 1 (TIVA, n = 20) and group 2 (inhalation anesthesia, n = 19). Group 1 patients were induced and maintained with continuous infusion of remifentanil and propofol using a target controlled infusion device. Patients in group 2 were induced with sevoflurane and N2O using mask ventilation, and then anesthesia was maintained with sevoflurane and N2O. The QTc interval, heart rate and mean arterial pressure were measured prior to induction, immediately following intubation, 10 minutes following intubation, following CO2 inflation, immediately following head-up position, 10 minutes following head-up position, following CO2 deflation-supine position respectively. RESULTS: In group 1, the ECG sampling showed no prolongation in the QTc intervals at all measured points. In group 2, QTc interval was significantly longer at all other measured points compared to prior to induction (P < 0.05). Except prior to induction, QTc intervals were significantly longer at all other measure points in group 2 compared to those in group 1 (P < 0.05). CONCLUSIONS: There was no QTc interval prolongation under the TIVA using propofol and remifentanil during laparoscopic cholecystectomy.

Pyomyositis of the iliacus muscle and pyogenic sacroiliitis after sacroiliac joint block: A case report / 대한마취과학회지

Sacroiliac joint block can be performed for the diagnosis and treatment of sacroiliac joint dysfunction. Although sacroiliac joint block is a common procedure, complications have not been reported in detail. We report a case of iliacus pyomyositis and sacroiliac joint infection following a sacroiliac joint block. A 70-year-old female patient received sacroiliac joint blocks to relieve pelvic pain. The patient was admitted to the emergency room two days after the final sacroiliac joint block (SIJB) with the chief complaints of left pelvic pain corresponding to a visual analogue scale (VAS) score of 9 and fever. A pelvic MRI indicated a diagnosis of myositis. After 1 month of continuous antibiotic therapy, the patient's erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level remained elevated. A 67Ga SPECT/CT was done. Abnormal uptake was seen at the left sacroiliac joint (SIJ), and septic sacroiliitis was suspected. The CRP normalized to 0.29 mg/dl and the ESR decreased to 60 mm/hr, and the patient had no fever after 57 days of antibiotic therapy. She was directed for follow up at an outpatient clinic.

The influence of DNA polymorphism of multidrug resistant 1 (MDR1) on the effect of midazolam pretreatment in children / 대한마취과학회지

BACKGROUND: Patients showed a different response following intravenous midazolam injection. Some children showed irritability or were not sedated by midazolam. We hypothesized that there may be genetic variations of the MDR1 gene, based on the response to midazolam. METHODS: One hundred and ninety-three pediatric patients were recruited in this study. Midazolam (0.1 mg/kg) was injected intravenously before surgery. Anxiety score (activity, vocalizations, emotional expressivity, state of apparent arousal) was checked before and 5 minutes after midazolam injection. In addition, other manifestations after midazolam injection were recorded. After anesthesia, 2 ml of blood was sampled. Children were genotyped MDR1. Haplotype was analyzed using the software package PHASE, version 2.0. RESULTS: The observed frequencies of MDR1 haplotype of TTT, TGC, CAC, CGC were 0.334, 0.205, 0.182 and 0.225, respectively. There was no significant correlation between the response of midazolam and the MDR1 haplotype of TTT, TGC, CAC or CGC (P = 0.98). CONCLUSIONS: Genotyping of MDR1 may not be related to the response of midazolam in children.

Application of the continuous autotransfusion system (CATS) to prevent transfusion-related hyperkalemia following hyperkalemic cardiac arrest in an infant: A case report / 대한마취과학회지

Transfusion-induced hyperkalemia can lead to cardiac arrest, especially when the patient rapidly receives a large amount of red blood cells (RBCs), previously stored for a long period of time, irradiated or both. We report on a case of application of the Continuous AutoTransfusion System (CATS) to wash RBCs, in order to lower the high potassium (K+) level in the packed RBCs unit, during massive transfusion following transfusion-induced hyperkalemic cardiac arrest. After the washing process using CATS, there was no more electrocardiographic abnormality or cardiac arrest due to hyperkalemia. This case emphasizes the potential risk to develop transfusion-related hyperkalemic cardiac arrest, during massive transfusion of irradiated, pre-stored RBCs. CATS can be effectively used to lower the K+ concentration in the packed RBCs unit, especially when the risk of transfusion-induced hyperkalemia is high.

Anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients: the issue of safety in infant and younger children / 대한마취과학회지

BACKGROUND: The purpose of this study was to assess the safety issues concerning anesthetic management of video-assisted thoracoscopic surgery (VATS) in pediatric patients. METHODS: The medical records of 52 pediatric patients undergoing VATS using general anesthesia and one-lung ventilation (OLV) were reviewed. OLV was achieved with a Fogarty catheter (n = 23) or endobronchial intubation (n = 7) in patients 50 mmHg) was observed more frequently in group Y (40%) than in group O (0%; P < 0.05). The difference between the ETCO2 and PaCO2 was 10.4 +/- 8.9 mmHg in group Y and 4.6 +/- 3.9 mmHg in group O (P < 0.05). Hypercarbia and acidosis occurred more frequently in patients with CO2 insufflation than those without insufflation in group Y. CONCLUSIONS: Although the anesthesia for VATS in pediatric patients was successfully accomplished, the infants and younger children presented with more intra-operative problems when compared with older children. The anesthetic management for VATS in infants and younger children requires careful and vigilant monitoring.

Transfusion-free anesthetic management for open heart surgery in a neonate: A case report / 대한마취과학회지

In small infants or neonates, open heart surgery without transfusion can have many risks regarding inadequate oxygen delivery and coagulopathy. However, if parents refuse blood transfusion, cardiac surgery without transfusion should be considered. We report a case of bloodless cardiac surgery in a 2.89 kg neonate with Jehovah's Witness parents. Blood conserving strategies were used. Preoperatively, erythropoietin and iron were supplemented to increase the hemoglobin level. Intraoperatively, techniques for minimizing blood loss were used, such as reducing priming volume for cardiopulmonary bypass, a blood salvage system, and modified ultrafiltration. Postoperatively, pharmacologic agents were administered and blood sampling was minimized.

Anesthetic management with scalp nerve block and propofol/remifentanil infusion during awake craniotomy in an adolescent patient: A case report / 대한마취과학회지

Despite of various neurophysiologic monitoring methods under general anesthesia, functional mapping at awake state during brain surgery is helpful for conservation of speech and motor function. But, awake craniotomy in children or adolescents is worrisome considering their emotional friabilities. We present our experience on anesthetic management for awake craniotomy in an adolescent patient. The patient was 16 years old male who would undergo awake craniotomy for removal of brain tumor. Scalp nerve block was done with local anesthetics and we infused propofol and remifentanil with target controlled infusion. The patient endured well and was cooperative before scalp suture, but when surgeon sutured scalp, he complained of pain and was suddenly agitated. We decided change to general anesthesia. Neurosurgeon did full neurologic examinations and there was no neurologic deficit except facial palsy of right side. Facial palsy had improved with time.

Cardiac arrest induced by tension pneumothorax during ventilating bronchoscopy: A case report / 대한마취과학회지

Tension pneumothorax during ventilating bronchoscopy for foreign body removal is a rare but life-threatening complication. The authors present a case of cardiac arrest caused by tension pneumothorax in a 9-month-old girl who underwent ventilating bronchoscopy for foreign body (peanut) removal. Tension pneumothorax was due to tracheobronchial lacerations caused by a bronchoscope. The patient was successfully resuscitated by cardiopulmonary resuscitation and chest tube insertion. The airway injury was effectively repaired by thoracotomy under extracorporeal membrane oxygenation.

Unilateral Atelectasis during Total Hip Replacement Surgery under Regional Anesthesia: A case report / 대한마취과학회지

Even though atelectasis develops rare during anesthesia and/or surgical operation, it may be very important complication because it can be fatal. Atelectasis may be due to airway or bronchus obstruction, compression of the lung by position, primary surfactant deficiency, increased pleural pressure due to fluid or air in the pleural space, chest wall restriction due to skeletal deformity and/or muscular weakness. We report a case of acute intraoperative unilateral lobar atelectasis in 87-years-old woman patient undergoing regional anesthetic for total hip replacement surgery.