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Plasma drug concentration is the variable linking dose to effect. The decrement time required for plasma concentration of anesthetic agents to decrease by 50% (context‐sensitive half‐time) correlates with the time taken to regain consciousness. However, the decrement time to consciousness may not be 50%. An effect compartment concentration is associated more closely with return of consciousness than plasma concentration. An alternative decrement time, the time required for propofol to decrease to a predetermined effect compartment concentration associated with movement (eg, 2 µg.ml−1), was used to simulate time for the concentration to decrease from steady state at a typical targeted effect compartment concentration 3.5 µg.ml−1 in children. These times were short and reflected a decrement time to consciousness (CSTAWAKE) increase that was small with longer infusion time. CSTAWAKE ranged from 7.5 min in 1‐year‐old infant given propofol for 15 min to 13.5 min in a 15‐year‐old adolescent given a 2‐hour infusion. Changes in decrement time with age reflect maturation of drug clearance. Neonates had prolonged increment times, 10 min after 15 min infusion and 18 min after 120 min infusion using a target concentration of 3.5 µg.ml−1. Decrement times to a targeted arousal concentration are context‐sensitive. Use of a higher target concentration of 6 µg.ml−1 doubled decrement times. Decrement times are associated with variability: delayed recovery beyond these simulated times is likely more attributable to the use of adjuvant drugs or the child's clinical status. An understanding of propofol decrement times can be used to guide recovery after anesthesia. [ABSTRACT FROM AUTHOR]

Background: Dexmedetomidine is a useful anesthetic adjunct, increasingly popular during pediatric surgery and procedural sedation. Its half‐life of 2–3 hours might prolong recovery and discharge times when compared with an un‐supplemented propofol anesthetic. This may create an additional burden in a busy post‐anesthetic care unit (PACU). Aim: To investigate whether intraoperative adjuvant dexmedetomidine delays PACU discharge in patients undergoing propofol anesthesia for day surgery or procedural investigations with minimal anticipated post‐procedural pain. Methods: We conducted a retrospective review of outpatient procedures performed during a six‐month period including pediatric patients, ASA physical status I‐III, who underwent intravenous anesthesia with propofol and remifentanil for magnetic resonance imaging (MRI), strabismus repair, upper gastrointestinal endoscopy, or combined upper/lower gastrointestinal endoscopy. Patients receiving a sedative premedication, long‐acting opioids, or volatile anesthetics for maintenance of anesthesia, were excluded. Duration of PACU stay was compared for patients who did or did not receive intraoperative dexmedetomidine in the four procedure groups. Results: Charts were reviewed for 359 patients; 130 (36%) received dexmedetomidine. Median differences in duration of PACU stay for dexmedetomidine versus non‐dexmedetomidine cases were: 5 minutes (95%CI 0 to 10, p=0.037) for MRI; 5 minutes (95%CI −3 to 15, p=0.258) for strabismus surgery; 7 minutes (95%CI 3 to 10, p<0.001) for upper endoscopy; and 5 minutes (95%CI 1 to 12, p=0.021) for combined upper/lower endoscopy. Linear regression (F=61.1, adjusted R2=0.40) indicated a significant relationship between dexmedetomidine dose (estimate 14.6 minutes per μg/kg, 95%CI 8.2 to 21.1, p<0.001) and duration of PACU stay. Conclusion: We found evidence for a small association of intraoperative dexmedetomidine with duration of recovery from propofol anesthesia for a set of common outpatient procedures, with a potential dose relationship equivalent to approximately 15 minutes delay per μg/kg dexmedetomidine administered. Future research into the benefits of dexmedetomidine in pediatric anesthesia should further evaluate this relationship. [ABSTRACT FROM AUTHOR]

Pharmacokinetic parameter estimates are used in mathematical equations (pharmacokinetic models) to describe concentration changes with time in a population and are specific to that population. Simulation using these models and their parameter estimates can enrich understanding of drug behavior and serve as a basis for study design. Pharmacokinetic concepts are presented pertaining to future designs of dexmedetomidine target‐controlled infusion pumps in children. This manuscript provides the pediatric anesthesiologist with an understanding of the nuances that should be considered when using target‐controlled infusion pumps; how the central volume may differ between populations, how clearance changes with age, and the impact of adverse effects on dose. In addition, the ideal loading dose and rate of delivery to achieve target concentration without adverse cardiovascular effects are reviewed, and finally, dose considerations for obese children, based on contact‐sensitive half‐time, are introduced. An understanding of context‐sensitive half‐time changes with age enables anesthetic practitioners to better estimate duration of effect after cessation of dexmedetomidine infusion. Use of these known pharmacokinetic parameters and covariate information for the pediatric patient could readily be incorporated into commercial target‐controlled infusion pumps to allow effective and safe open‐loop administration of dexmedetomidine in children. [ABSTRACT FROM AUTHOR]

Background: Approaches to pediatric induction of anesthesia vary widely. While oral sedative premedication and inhalational induction are common, total intravenous anesthesia is becoming increasingly popular. Total intravenous anesthesia without anxiolytic premedication, which is the most commonly used technique in our hospital, requires intravenous (IV) cannula placement in an awake child. Aims: To quantify the success rate of IV cannula placement in 1 or 2 attempts and to identify success factors and barriers. Methods: With ethical approval and written informed consent from participating anesthesiologists, a prospective audit of IV cannulation was undertaken over a 1‐month period. The attending anesthesiologist captured basic demographics, IV insertion characteristics, setting, distraction techniques, the behavior of the child, number of attempts, and success/failure. A logistic regression model for successful IV cannulation was created. Anesthesiologists and procedural suite nurses participated in semi‐structured interviews to identify success factors, barriers, and teaching approaches. Results: Data from 984 cases were analyzed. IV induction was planned in 562 cases, and IV cannulation was successful in 90% of these patients. Anxiolytic premedication was given in 6% of cases. Observations indicated that 64% of children were pain‐ and reaction‐free, and 90% experienced minimal or no reaction. Predictors for success included older child's age and child behavior at first encounter. Qualitative interview data from 13 participants suggested success factors included effective distraction, preparing the family for IV induction, parental presence, support of the operating room team, effective use of local analgesic cream, adapting the approach to the individual child, and the anesthesiologist's efficiency. Barriers included needle phobia, uncooperative child, anxious parents, ineffective use of analgesic cream, and unfavorable anatomy. Distraction techniques varied by age and developmental stage of the child. Conclusions: Cannulation for planned IV induction is feasible for most children, enabling increased use of total intravenous anesthesia as an institutional anesthetic strategy. [ABSTRACT FROM AUTHOR]

Aims: Manual propofol infusion regimens for neonates and infants have been determined from clinical observations in children under the age of 3 years undergoing anesthesia. We assessed the performance of these regimens using reported age‐specific pharmacokinetic parameters for propofol. Where performance was poor, we propose alternative dosing regimens. Methods: Simulations using a reported general purpose pharmacokinetic propofol model were used to predict propofol blood plasma concentrations during manual infusion regimens recommended for children 0‐3 years. Simulated steady state concentrations were 6‐8 µg.mL−1 in the first 30 minutes that were not sustained during 100 minutes infusions. Pooled clinical data (n = 161, 1902 plasma concentrations) were used to determine an alternative pharmacokinetic parameter set for propofol using nonlinear mixed effects models. A new manual infusion regimen for propofol that achieves a steady‐state concentration of 3 µg.mL−1 was determined using a heuristic approach. Results: A manual dosing regimen predicted to achieve steady‐state plasma concentration of 3 µg.mL−1 comprised a loading dose of 2 mg.kg−1 followed by an infusion rate of 9 mg.kg−1.h−1 for the first 15 minutes, 7 mg.kg−1.h−1 from 15 to 30 minutes, 6 mg.kg−1.h−1 from 30 to 60 minutes, 5 mg.kg−1.h−1 from 1 to 2 hours in neonates (38‐44 weeks postmenstrual age). Dose increased with age in those aged 1‐2 years with a loading dose of 2.5 mg.kg−1 followed by an infusion rate of 13 mg.kg−1.h−1 for the first 15 minutes, 12 mg.kg−1.h−1 from 15 to 30 minutes, 11 mg.kg−1.h−1 from 30 to 60 minutes, and 10 mg.kg−1.h−1 from 1 to 2 hours. Conclusion: Propofol clearance increases throughout infancy to reach 92% that reported in adults (1.93 L.min.70 kg−1) by 6 months postnatal age and infusion regimens should reflect clearance maturation and be cognizant of adverse effects from concentrations greater than the target plasma concentration. Predicted concentrations using a published general purpose pharmacokinetic propofol model were similar to those determined using a new parameter set using richer neonatal and infant data. [ABSTRACT FROM AUTHOR]

Summary: Background: Medication errors pose a significant risk perioperatively. In the perioperative environment, common medication administration processes are not typically performed. Given the common administration of potentially harmful medications and the potential for medication errors, patient risk is substantial. Specifically, intravenous acetaminophen has been used more frequently in the perioperative period which yielded an increase in medication administration errors reported. Aims: This project was initiated by Cincinnati Children's Hospital after an increase in perioperative acetaminophen dosing errors was reported. After mapping the administration process of perioperative acetaminophen, we sought to reduce medication errors by the use of a safety checklist. Acetaminophen was used as a surrogate for other perioperative medications in this quality improvement project. Methods: Use of a failure mode effects analysis assisted the team in understanding the failures of the process of safe medication administration. Subsequently, key drivers of this process were designed to include accurate understanding and documentation of medication history, consistent communication between perioperative caregivers, and an efficient checklist process. A multidisciplinary team conducted a series of tests to modify key drivers. Data were collected by utilizing data from a paper checklist, prior to the electronic medical record change that was prompted by this study. A total of 633 checklists and electronic medical records were analyzed during a 6‐month period; data were analyzed using control charts and statistical process control methods. Results/Analysis: The percentage of compliance with the safe administration checklist for acetaminophen in the preoperative period increased to 97%. Use of the paper checklist likely prompted the appropriate increase in compliance with safe administration. Additionally, provider‐specific feedback produced a significant increase in compliance with the use of the checklist. Conclusion: Application of quality improvement methods, specifically a safety checklist, were utilized to improve the safe administration of acetaminophen during the perioperative period. Increasing reliability of accurate delivery and administration of medication to patients are crucial in optimizing patient safety. Use of a medication safety checklist may be beneficial in reducing potential administration errors, specifically for high‐risk medications. [ABSTRACT FROM AUTHOR]

Background In children, only a few studies have compared different modes of propofol infusion during a total intravenous anesthesia ( TIVA) with propofol and remifentanil. The aim of this study was to compare Bispectral Index ( BIS) profiles (percentage of time spent at adequate BIS values) between four modes of propofol infusion: titration of the infusion rate on clinical signs ( TIVA0), titration of the infusion rate on the BIS (TIVABIS), target controlled infusion ( TCI) guided by the BIS either with the Kataria model ( TCI KBIS) or the Schnider model ( TCI SBIS). Methods Sixty-six children (aged from 4 to 14 years) were prospectively randomized into one of the four groups. In the TIVA0 group, the anesthesiologist was blinded to the BIS. In each group, the percentage of time with adequate BIS values (45-55), the bias, and imprecision were calculated. Results The propofol consumption was similar in the four groups. During the maintenance phase, the percentage of time spent in the targeted BIS range was significantly lower in the TIVA0 group compared to the three other groups ( TIVA0: 31% ± 22, TIVABIS: 59% ± 17, TCI KBIS: 53% ± 12, TCI SBIS: 56% ± 17). The bias was not statistically different between the four groups, but the imprecision was larger for the TIVA0 group. Compared to the Kataria model, the Schnider model was associated with shorter time delay to reach the desired BIS, to eyes opening, and to tracheal extubation. Conclusions Propofol administration using manual infusion guided by clinical signs was associated with higher risks of over- or underdosage when compared to BIS-guided administrations. When propofol infusion was guided by the BIS, no major difference was found between TIVA and TCI (either with the Kataria or the Schnider model). This study highlights the need of a pharmacodynamic feedback during propofol anesthesia in children. [ABSTRACT FROM AUTHOR]

Propofol is an intravenous anesthetic agent commonly used intraoperatively as well as in the intensive care unit. Known short‐term effects of propofol can include apnea, hypotension, and bradycardia. In children, the rarer adverse sequelae of intravenous anesthetics have received little attention. We present the case of a thirteen‐year‐old male who incidentally developed uric acid crystals in his urine following a short‐duration propofol infusion. [ABSTRACT FROM AUTHOR]

Background Esophagogastroduedenoscopy ( EGD) in children is usually performed under general anesthesia. Anesthetic goals include minimization of airway complications while maximizing operating room ( OR) efficiency. Currently, there is no consensus on which anesthetic technique best meets these goals. We performed a prospective randomized study comparing three different anesthetic techniques. Aims To evaluate the incidence of respiratory complications (primary aim) and institutional efficiency (secondary aim) among three different anesthetic techniques in children undergoing EGD. Methods Subjects received a standardized inhalation induction of anesthesia followed by randomization to one of the three groups: Group intubated, sevoflurane (IS), Group intubated, propofol (IP), and Group native airway, nonintubated, propofol (NA). Respiratory complications included minor desaturation (SpO2 between 94% and 85%), severe desaturation (SpO2 < 85%), apnea, airway obstruction/laryngospasm, aspiration, and/or inadequate anesthesia during the endoscopy. Evaluation of institutional efficiency was determined by examining the time spent during the different phases of care (anesthesia preparation, procedure, OR stay, recovery, and total perioperative care). Results One hundred and seventy-nine children aged 1-12 years (median 7 years; 4.0, 10.0) were enrolled (Group IS N = 60, Group IP N = 59, Group NA N = 61). The incidence of respiratory complications was higher in the Group NA (0.459) vs Group IS (0.033) or Group IP (0.086) ( P < 0.0001). The most commonly observed complications were desaturation, inadequate anesthesia, and apnea. There were no differences in institutional efficiency among the three groups. Conclusion Respiratory complications were more common in Group NA. The use of native airway with propofol maintenance during EGD does not offer advantages with respect to respiratory complications or institutional efficiency. [ABSTRACT FROM AUTHOR]

Introduction Laryngeal cleft is a rare congenital malformation that is being reported with increasing frequency. Diagnosis requires suspension microlaryngoscopy under general anesthesia during spontaneous respiration. Repair may be attempted by a minimally invasive endoscopic approach or open surgical repair. The authors report on their experience with total intravenous anesthesia ( TIVA) and spontaneous ventilation without an endotracheal tube during suspension laryngoscopy and CO2 laser application for this specific surgical procedure. Of particular interest were the rate at which this technique failed and rescue techniques were employed and the ability to predict patients in whom this might occur. Methods Between July 2004 and September 2012, 110 endoscopic laryngeal cleft repairs were completed under TIVA with spontaneous ventilation without an endotracheal tube. Anesthetic induction was achieved by inhalation of sevoflurane and oxygen by mask or infusion of propofol at 300 mcg kg−1 min−1 and remifentanil at 0.05-1.0 mcg kg−1 min. The vocal cords and surgical site were sprayed with up to 2 mg kg−1 of 4% lidocaine. If the oxygen saturation decreased during the procedure or the patient became apneic, a rescue process utilizing jet ventilation or intermittent intubation was instituted. Results Ten (9.1%) of the 110 cases required rescue (95% confidence interval [ CI]: 5.0-15.8%). The most prevalent comorbidities included reactive airway disease, chronic lung disease, failure to thrive, developmental delay, and an unrelated syndrome. Thirty-nine patients (36%) had reactive airway disease and twelve (11%) had chronic lung disease. Intraoperative complications included six cases requiring a brief, temporary period of intubation (5.5%) and four cases requiring a brief period of jet ventilation (3.6%). Conclusion The technique of TIVA with spontaneous respirations without an endotracheal tube is a safe and effective technique for laryngeal cleft repair. Although the potential for intraoperative adverse events may be high, the actual rate was very low. The need to convert to other techniques is not significant although the children who did require brief periods of jet ventilation or intubation tended to have reactive airway disease or chronic lung disease. [ABSTRACT FROM AUTHOR]

Background and Objectives Impairment of blood coagulation is one of the main side effects of volume replacement, particularly if artificial colloids such as hydroxyethyl starch ( HES) and gelatine preparations are used. This animal study aimed to evaluate the effect of a single fast intravenous crystalloid or colloid fluid bolus on blood coagulation as measured by rotation thromboelastometry ( ROTEM®). Methods Thirty-two anesthetized piglets were infused with a rapid 20 ml·kg−1 fluid bolus of either normal saline ( NS), 4% gelatine, 5% albumin or 6% HES 130/0.4 ( n = 8 per group) over a period of 2 min. Hemostasis was assessed by ROTEM® before and 1 min after fluid administration. Within-group differences were analyzed by Wilcoxon test, and additionally overall Kruskal-Wallis test followed by posthoc Mann-Whitney U-test were applied to detect differences between groups. Results All fluids caused a significant weakening of clot strength within groups. HES and gelatine showed a significantly stronger impairment of clot growth and maximum clot firmness as compared with albumin and normal saline. Impairment of fibrin polymerization was more pronounced following HES as compared with all other fluids. Conclusion After moderate but very fast volume loading, HES and gelatine impair blood coagulation to a larger extent as compared with albumin or normal saline, while no significant differences were observed between both artificial colloids. [ABSTRACT FROM AUTHOR]

Aim: We performed a retrospective audit of intravenous morphine infusion administered to children in an effort to characterize the relationship between dose and age. Methods: A retrospective audit of morphine infusions was reviewed for a 24-months period and included all children who received continuous intravenous nurse-controlled morphine infusions and patient-controlled analgesia; a population undergoing acute and elective surgical procedures, as well as medical and oncological treatments. The relationship between age and infusion rate was investigated using nonlinear mixed effects models. Results: There were 886 children whose data were acceptable for review. Morphine dose increased with age from 9.97 (CV 28%) μg·kg−1 per h in neonates. The Hill equation with an exponential of 1.5 best described these changes. Morphine rate reached 90% of its mean final rate of 22.5 (CV 167%) μg·kg−1 per h, observed in teenagers, at approximately 5 years of age. There was considerable uncertainty of this age-morphine rate profile, and the maturation half-life of this profile was 20 months of age (CV 632%). An increase in dosing variability was observed with increasing age. Conclusions: Morphine infusions at steady-state did not mirror clearance maturation in children nursed in our hospital. We suggest that initial infusion rates in children are started at 10 μg·kg−1 per h in neonates, 15 μg·kg−1 per h in toddlers and 25 μg·kg−1 per h in children above the age of 5 years. The large variability associated with infusion rates means that subsequent infusion rates will depend on feedback from pain scores, adjuvant medications and adverse effects. [ABSTRACT FROM AUTHOR]

Propofol is a popular agent for providing intraoperative sedation in pediatric population during lumbar puncture and spinal anesthesia. Adjuvant-like clonidine is used increasingly in pediatric anesthesia to provide postoperative analgesia with a local anesthetic agent. The aim of this study was to assess the effects of intrathecal and intravenous clonidine on postoperative analgesia/sedation and intraoperative requirements of propofol after intrathecal bupivacaine for orthopedic surgery in children. Fifty-nine ASA I and II children aged 6-8 year undergoing orthopedic surgery were randomized to receive intrathecal 0.5% bupivacaine 0.2-0.4 mg·kg and intravenous 2 ml saline (Group B), intrathecal 0.5% bupivacaine 0.2-0.4 mg·kg plus 1 μg·kg clonidine and intravenous 2 ml saline (Group BCit), and 0.5% bupivacaine 0.2-0.4 mg·kg and intravenous 1 μg·kg clonidine in 2 ml of saline (Group BCiv). Intraoperative sedation was maintained with 20-50 μg·kg·min of propofol infusion. The requirements of propofol, time to first rescue analgesia, and postoperative pain or sedation scores were assessed. The duration of motor and sensory blocks and perioperative adverse events were determined. Clonidine significantly prolonged the time to first rescue analgesia and reduced the requirements of propofol sedation whether administered intravenously or intrathecally. The mean Children and Infants Postoperative Pain Scale scores of children were significantly lower in groups BCit and BCiv than in group B. Postoperative sedation scores were higher in groups BCit and BCiv than in group B. Intrathecal clonidine significantly prolonged the time to regression of the sensory block and recovery of motor block. There were no significant differences among the three groups regarding the incidence of perioperative adverse events. Intrathecal or intravenous clonidine similarly provided better postoperative analgesia and sedation and reduced the requirements of propofol. Only intrathecal clonidine prolonged the duration of sensory and motor blocks. [ABSTRACT FROM AUTHOR]

Ketamine is a general anesthetic agent widely used for pediatric procedural sedation outside the operating theater by nonanesthesiologists. In a setting where efficacy and safety of the agent are paramount, there are conflicting recommendations in terms of optimal mode of parenteral administration, as well as optimal dosage and need for the coadministration of adjunctive agents to decrease side effects. We investigated existing evidence to determine whether ketamine should be best administered intravenously or intramuscularly. This analysis was made difficult by limited direct comparisons of both modes of parenteral administration and a lack of consistent definitions for key outcomes such as ‘effectiveness,’‘adverse events,’‘hypoxia,’‘ease of completion of the procedure,’ and ‘satisfaction’ across studies that have evaluated ketamine. Based on large data sets, the safety and efficacy of both modes of administration are broadly similar. Although data on head to head comparisons of intravenous and intramuscular ketamine is limited, based on our analysis, we conclude that the trends indicate ketamine is ideally administered intravenously. [ABSTRACT FROM AUTHOR]

Objectives: Mivacurium, rocuronium, and vecuronium are neuromuscular blocking agents (NMB) commonly used in pediatric day-case anesthesia. Mivacurium is the most appropriate NMB for short surgical procedures where NMB drugs were required but is not available in all countries. Aim: We evaluated the operating room time minimization after reduced-dose rocuronium (0.45 mg·kg−1) during elective day-case tonsillectomy in children. Methods/Materials: One hundred and five children (6–9 years, ASA I/II status) scheduled for day-case tonsillectomy were included in prospective, double blind clinical study. Children were randomly divided in three equal groups. All children were premedicated (midazolam 0.25 mg·kg−1 orally, EMLA). Anesthesia was induced (2.5 mg·kg−1) and maintained (0.1 mg·kg−1·min−2) by propofol and alfentanil (0.0015 mg·kg−1·min−1) and supplemented by inhalation mixture of 50% of O2/Air. Neuromuscular block was achieved by vecuronium (0.1 mg·kg−1) ( V) or rocuronium in standard (0.6 mg·kg−1) ( R) or reduced dose (0.45 mg·kg−1) (LD). Neuromuscular transmission was monitored by acceleromyography. Time analysis of NMB drugs action was performed. Results: Time difference from the end of tonsillectomy to T90 neuromuscular block recovery was significantly shorter in LD Group (7.3 ± 0.41 min), ( V = 15.9 ± 1.06, R = 16.0 ± 1.7 min) ( P = 0.0011). The onset time of neuromuscular block was prolonged in LD Group (LD=3.1 ± 0.4, R = 1.3 ± 0.4, V = 2.2 ± 0.2 min) ( P = 0.0039) without changing the intubating conditions. The maximum operation room time saving per each tonsillectomy was 37% in LD Group (Group V 21%, Group R 17%) ( P = 0.0001). Low incidence of postoperative nausea and vomiting (PONV) 3–6% (0.4577) and good visual analog scale (VAS) score (≤2) (0.5969) were found in all study groups 12 h after surgery. Conclusions: Reduced-dose rocuronium in addition with propofol and alfentanil in children where volatile anesthetics are not used effectively saves the operating room time during short elective surgical procedures, avoids delays in patient recovery, allows high level of acceptable intubating conditions, and improves the optimal surgical work. Low incidences of PONV as VAS score may achieved successfully. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to determine the age-specific bolus dose of remifentanil (ED50) to facilitate tracheal intubation without the use of neuromuscular blocking agents. Methods: ASA 1–2 subjects were recruited into three groups of 0–3 months (group I), 4–12 months (group II), and 1–3 years (group III) of age. A sequential up-and-down design determined the remifentanil bolus dose, which was initially started at 3 mcg·kg−1 and adjusted in 1 mcg·kg−1 increments (range 1–6 mcg·kg−1). Following pretreatment with glycopyrrolate 10 μg·kg−1 and an induction dose of propofol 5 mg·kg−1, remifentanil was administered with a blinded study investigator commencing tracheal intubation after 60 s. After tracheal intubation, the time to return of spontaneous ventilation was measured. Logistic regression was used to predict the ED50 and ED95 of remifentanil. Results: Sixty-four subjects were recruited. Tracheal intubation was successful at first attempt in over 90% of subjects in each age group. Satisfactory intubating conditions were achieved in 85%, 63%, and 75% of subjects in groups I, II, and III, respectively. The logistic regression results for ED50 (95% CI) were 3.1 (2.5–3.8), 3.7 (2.0–5.4), and 3.0 (2.1–3.9) mcg·kg−1, and ED95 (95% CI) were 5.0 (3.0–7.0), 9.4 (1.5–17.4), and 5.6 (2.9–8.4) mcg·kg−1 in groups I, II, and III, respectively. Infants aged 4–12 months (group II) showed a marked variability in dose response; however, the mean ED50 and ED95 were not different to groups I and III. Older children had a longer duration of apnea than infants, 331 vs 180 s ( P < 0.05). Discussion: The ED50 of remifentanil for tracheal intubation was higher in all age groups than previously reported. Ideal intubating conditions were achieved in 50% of subjects with remifentanil doses of 3.1–3.7 mcg·kg−1. Higher doses will be required for higher success rates and with anticholinergic pretreatment, doses of up to 6 mcg·kg−1 were tolerated, without adverse effects, in two patients. Further investigation of the variability in dose response in infants and assessment of the safety this technique is warranted. [ABSTRACT FROM AUTHOR]

Background: With an increase in the frequency of interventional radiology procedures in pediatrics, there has been a corresponding increase in demand for procedural sedation to facilitate them . The purpose of our study was to compare the frequency of adverse effects, sedation level, patient recovery characteristics in pediatric patients receiving intravenous propofol fentanyl combination with or without ketamine for interventional radiology procedures. Our main hypothesis was that the addition of ketamine would decrease propofol/fentanyl associated desaturation. Methods and materials: Sixty consenting American Society of Anesthesia physical status I–III pediatric patients undergoing interventional radiology procedures under sedation were studied according to a randomized, double-blinded, institutional review board approved protocol. Group 1 received propofol 0.5 mg·kg−1 + fentanyl 1 μg·kg−1 + ketamine 0.5 mg·kg−1, and group 2 received propofol 0.5 mg·kg−1 + fentanyl 1 μg·kg−1 + same volume of %0.9 NaCl intravenously. Results: While apnea was not observed in any of the groups, there were three cases (10%) in group 1, and nine cases (30%) in group 2 with oxygen desaturation ( P = 0.052). In group 1, 12 (40%) patients and, in group 2, 21 (70%) patients required supplemental propofol during the procedure ( P = 0.021). There was no evidence for difference between groups in terms of other side effects except nystagmus. Conclusions: In conclusion, addition of low dose ketamine to propofol-fentanyl combination decreased the risk of desaturation and it also decreased the need for supplemental propofol dosage in pediatric patients at interventional radiology procedures. [ABSTRACT FROM AUTHOR]

Background: The license for i.v. paracetamol has recently been extended to include term neonates and infants aged 1 year, at a uniform dose across this age range of 7.5 mg·kg−1, total daily dose 30 mg·kg−1·day−1. We were interested to survey current i.v. paracetamol prescribing practices of anesthetists in the UK, in neonates and infants under 1 year of age. Methods: We conducted an online survey of 94 linkmen of the Association of Pediatric Anesthetists of Great Britain and Ireland Linkmen representing both general and specialist hospitals and 90 members of the British Pediatric Pain Travelling Club representing the pediatric acute pain teams throughout the UK and Ireland. Results: A total of 105/184 (57%) responded to the survey on behalf of 78 regions and 27 pediatric acute pain teams. Over half (54%) of the respondents indicated i.v. paracetamol use in infants under 1 year of age. A wide range of loading and maintenance doses were used. Total daily doses exceeded the license for age 1–12 months in 70% of cases; for the 36 week postconceptional age (PCA)-1 month age range the proportion was 50%. Over 80% of total daily dosing from age 36 weeks PCA to 1 year fell within dosing suggested by pharmacokinetic studies. Close to 40% of respondents who used i.v. paracetamol in infants, also indicated use in preterm age groups. The total daily dose used in preterm neonates was within the range suggested by pharmacokinetic studies, in over 90% of cases in the age range 32–36 weeks PCA, and for 60% in the under 32 weeks PCA age group. Conclusions: This survey demonstrates i.v. paracetamol dosing in infants in the UK and Ireland is frequently above the licensed dose and outside the licensed age range but is in keeping with doses suggested by pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

Aim: We aimed to produce a racemic ketamine manual infusion regimen capable of maintaining a steady-state blood concentration associated with anesthesia in children aged 1.5–12 years. Method: The literature was searched for a ketamine blood concentration associated with anesthesia in humans. Pharmacokinetic parameter estimates were taken from published studies of infusion data in children and used in a pharmacokinetic simulation program to predict likely ketamine blood concentrations during infusions. A variability of 10% was allowed about the chosen target concentration. Results: A target concentration of 3 mg·l−1 was chosen for simulation modeling. This target is greater than that associated with anesthesia when supplemented by nitrous oxide or midazolam in adults. Arousal to light touch or voice appears to occur at a mean plasma concentration of 0.5 mg·l−1 in both children and adults. A loading dose of 2 mg·kg−1 followed by an infusion rate of 11 mg·kg−1·h−1 for the first 20 min, 7 mg·kg−1·h−1 from 20 to 40 min, 5 mg·kg−1·h−1 from 40 to 60 min and 4 mg·kg−1·h−1 from 1 to 2 h resulted in a steady-state target concentration of 3 mg·l−1 in children 1.5–12 years. Arousal, either spontaneous or to speech, is anticipated 3 h 47 min after a 2 h infusion in an average 6-year-old child. The context sensitive half-time in children was shorter than in adults after 1.5 h, rising from 30 min at 1 h to 55 min at 5 h after an infusion of 3 mg·kg−1·h−1 in a 10 kg child. Conclusion: Children require higher infusion rates than adults to maintain steady-state concentrations of 3 mg·l−1 and have shorter context sensitive half-times than adults after prolonged infusion. These differences can be attributed to age-related pharmacokinetics. We anticipate slow return to full consciousness after prolonged infusion, suggesting that a lower target concentration with supplementation from adjuvant short acting anesthetic drugs may be advantageous. [ABSTRACT FROM AUTHOR]

Background: Pediatric intestinal biopsy procedures including considerable transpharyngeal manipulation of a wire-guided metal capsule require adequate sedation or anesthesia. This retrospective cohort study was designed to evaluate intravenous sedation with ketamine and low-dose midazolam in young children undergoing these procedures before and also after discharge from the hospital. Methods: A total of 244 biopsy procedures in 217 children under the age of 16 years were evaluated. All anesthesia records were reviewed according to a defined study protocol and in 145 cases the parents were also interviewed by telephone to obtain further information on possible adverse effects before and after discharge. Results: Ketamine and low-dose midazolam were carefully titrated by an experienced anesthesia team at an approximate dose ratio of 40 : 1 (total doses 2.3 and 0.05 mg·kg−1) in continuously monitored spontaneously breathing children. Possibly associated problems before discharge were salivation (5.7%), vomiting (4.9%), oxygen desaturation (3.3%), laryngospasm (2.5%) and rash (1.2%) according to the patient records and blurred vision (27%), nausea and vomiting (19%), vertigo (13%) and hallucinations or nightmares (3.5%) according to telephone interviews. Few, mild and transient problems remained after discharge from the hospital. Conclusions: Careful titration of ketamine and low-dose midazolam provides adequate sedation for nonsurgical pediatric short-term procedures also requiring considerable pharyngeal manipulation, particularly considering the low number of serious airway problems such as laryngospasm. The high incidence of late postoperative problems suggests that prospective studies should be designed for long-term follow-up of young children subjected to sedation or anesthesia. [ABSTRACT FROM AUTHOR]

Background: We used a multidrug intravenous anesthesia regimen with midazolam, ketamine, and propofol to provide anesthesia for children during magnetic resonance imaging (MRI). This regimen was compared with general anesthesia in a randomized comparative study. Outcome measures were safety, side effects and recovery variables in addition to adverse events in relation to age strata. Methods: The children received either general anesthesia with propofol, vecuronium and isoflurane [general endotracheal anesthesia (GET) group; n = 313] or intravenous anesthesia with midazolam, ketamine, and propofol [intravenous anesthesia (MKP) group; n = 342]. Treatment assignment was randomized based on the date of the MRI. Physiological parameters were monitored during anesthesia and recovery. Desaturation (SpO2 < 93%), airway problems, and the need to repeat the scan were recorded. The discharge criteria were stable vital signs, return to baseline consciousness, absence of any side effects, and ability to ambulate. Results: With the exception of two children (0.6%) in the MKP group, all enrolled children completed the scan. A significantly greater number (2.3%) required a repeat scan in the MKP group ( P < 0.05) and were sedated with a bolus dose of propofol. The total incidence of side effects was comparable between the MKP (7.7%) and GET groups (7.0%). Infants below the age of 1 year showed a significantly higher incidence of adverse events compared with the other age strata within each group. Within the MKP group, risk ratio was 0.40 and 0.26 when comparing infants aged below 1 year with the two older age strata, respectively. Recovery characteristics were comparable between both groups. Conclusions: Intravenous midazolam, ketamine and propofol provides safe and adequate anesthesia, comparable with that obtained from general endotracheal anesthesia, for most children during MRI. [ABSTRACT FROM AUTHOR]

The anesthesia care of a 14-year-old female patient with an acute exacerbation of myasthenia gravis (MG) and a full stomach who required emergency surgery for placement of a hemodialysis catheter is described. A nonventilated rapid sequence induction was successful with the use of propofol, lidocaine, remifentanil, cricoid pressure and no neuromuscular blocking agent. Although the use of combinations of i.v. anesthetic agents have been suggested for tracheal intubation without the need for neuromuscular blocking agents, none of these techniques has been advocated for rapid sequence intubation. We review existing literature on the topic of tracheal intubation using remifentanil and propofol without a neuromuscular blocking agent and on the topic of tracheal intubation of patients with MG using i.v. anesthesia and no neuromuscular blocking agents. [ABSTRACT FROM AUTHOR]

: A prospective observational case series of children receiving light general anesthesia for magnetic resonance imaging (MRI) was performed. Our purpose was to examine the merit of anesthesia and recovery/discharge times of combined remifentanil and propofol total intravenous anesthesia (TIVA) in spontaneously breathing children.: After IRB approval and informed consent, 56 patients receiving Remi/Propofol TIVA (Remifentanil 10 μg·ml−1 Propofol 10 mg·ml−1) were observed. Blood pressure, respiratory rate, endtidal CO2 (PECO2), oxygen saturation and temperature were recorded at the start and finish of anesthesia. In addition, induction and recovery times were noted. Recovery time was from scan completion until discharge from the initial recovery area. Discharge time was from scan completion to discharge home.: Fifty-six patients received Remi/Propofol TIVA. The mean Remi/Propofol recovery and discharge times were 8.9 and 28.2 min, respectively. There was a statistically significant decrease in respiratory rate and increase in CO2 from the start to the end of the procedure. During the scan, seven patients moved. One patient experienced postprocedure nausea and or vomiting.: The combination of remifentanil and propofol for TIVA may be an effective method of light general anesthesia in pediatric patients undergoing MRI. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess clinical signs of airway patency, airway intervention requirements and adverse events in 100 children receiving propofol total intravenous anesthesia for magnetic resonance imaging, with spontaneous ventilation and oxygenation via nasal prongs.Airway patency was clinically assessed and stepwise interventions were performed until a satisfactory airway was achieved. Propofol requirements, vital signs, procedure times and adverse events were also recorded.Ninety-three per cent of children had no signs of airway obstruction when positioned with a shoulder roll only, two required a chin lift, four required an oral airway and one required lateral positioning. The mean propofol induction dose was 3.9 mg·kg−1 (range 1.8–6.4 mg·kg−1). The mean propofol infusion rate was 193 μg·kg−1·min−1 (range 150–250 μg·kg−1·min−1). The initial and final mean respiratory rates were 26 and 23 b·min−1 (P < 0.05). Movement was more likely at lower infusion rates (mean 175 μg·kg−1·min−1). There were no respiratory or cardiovascular complications (calculated risk: 95% CI = 0–3%). The mean time from end of scan to discharge home was 44 min.This study demonstrates good preservation of upper airway patency and rapid recovery using general anesthetic doses of propofol in children. [ABSTRACT FROM AUTHOR]

: It has been suggested that nasal administration of s-ketamine may be used to improve sedation or premedication in combination with nasal midazolam in pediatric patients. In this study we measured and compared plasma concentrations of s-ketamine and its main metabolite s-norketamine after nasal and i.v. administration in preschool children.: During sevoflurane anaesthesia, 20 children, aged 1–7 years, weight 11–25 kg, received s-ketamine 2 mg·kg−1 either intranasally (Group IN,n = 10), or i.v. (Group IV,n = 10). Six venous blood samples were obtained up to 60 min after drug administration for measurement of s-ketamine and s-norketamine plasma concentrations.: Plasma concentrations [mean ± sd] of s-ketamine in group IN peaked at 355 ± 172 ng·ml−1 within 18 ± 13 min. vs. 1860 ± 883 ng·ml−1 within 3 ± 1 min. in group IV (P < 0.01). Plasma concentrations of s-norketamine in group IN peaked at 90 ± 128 ng·ml−1 within 50 ± 11 min. vs. 429 ± 277 ng·ml−1 within 40 ± 16 min. in group IV (P < 0.01). One child in group IN experienced rapid and high level s-ketamine absorption with a peak plasma concentration of 732 ng·ml−1 after 2 min., which decreased to 274 ng·ml−1 after 60 min. Systolic blood pressure and heart rate remained unaltered in both study groups after s-ketamine administration.: Nasal administration of s-ketamine 2 mg·kg−1 results in a wide spread of plasma concentrations and absorption times. Rapid and high level drug absorption after nasal drug administration is possible. The use of a pulse oximeter and continuous observation after nasal administration of s-ketamine for pediatric premedication is recommended. [ABSTRACT FROM AUTHOR]

: In this study we compared caudal with intravenous (i.v.) tramadol given pre- or postoperatively for pain relief in boys having hypospadias repair. : The study was approved by the Ethics Committee and informed written consent was obtained from the parents of each patient. Patients ( n = 134), aged 1–3 years, American Society of Anesthesiologists (ASA) physical status I, scheduled for hypospadias surgery were recruited. The patients were randomly allocated to one of the four groups: group I ( n = 33), received 2 mg·kg−1 (0.5 ml·kg−1) of caudal tramadol after the surgical procedure was completed, group II ( n = 33) received 2 mg·kg−1 (0.5 ml·kg−1) of caudal tramadol before incision, group III ( n = 34) received 2 mg·kg−1 tramadol intravenously, after surgery and group IV ( n = 34) received 2 mg·kg−1 tramadol intravenously, after anaesthesia induction. When the patients were fully awake in the recovery area, heart rate, arterial pressure, peripheral oxygen saturation, respiratory rate, pain and sedation scores were recorded at 5, 10, 15, 30, 60 min, and 2, 3, 4, 6, 12 and 24 h postoperatively and side-effects were noted. Pain was assessed using an objective pain score (OPS). : The OPS were lower in caudal tramadol groups than in i.v. tramadol groups only at 3 h ( P < 0.05). The duration of postoperative analgesia was longer in the caudal groups than in the i.v. groups ( P = 0.001). However, the duration of postoperative analgesia was unaffected by the timing of administration. : Caudal tramadol provides better and longer lasting postoperative analgesia than i.v. tramadol. These results also suggest that preoperative caudal tramadol did not provide any clinically perceptible benefits compared with postoperative caudal tramadol. [ABSTRACT FROM AUTHOR]

There are only a few clinical reports on the use of intravenous (i.v.) paracetamol in term neonates. This case report illustrates that when routes for administration of analgesics are restricted to i.v. only and when opioids are not indicated then i.v. paracetamol may be used. In our 4-day-old term infant, despite i.v. paracetamol for 48 h, the trough level during therapy was almost undetectable indicating rapid clearance. Although i.v. paracetamol is not licensed in this age group, it can prove very helpful when the only route of administration is intravenous. [ABSTRACT FROM AUTHOR]