Pharmacokinetics of Propofol after a Single Dose in Children Aged 1-3 Years with Minor Burns: Comparison of Three Data Analysis Approaches

Background: No complete pharmacokinetic profile of propofol is yet available in children younger than 3 yr, whereas clinical studies have demonstrated that both induction and maintenance doses of propofol are increased with respect to body weight in this age group compared to older children and adults. This study was therefore undertaken to determine the pharmacokinetics of propofol after administration of a single dose in aged children 1-3 yr requiring anesthesia for dressing change.

Methods: This study was performed in 12 children admitted to the burn unit and in whom burn surface area was less than or equal to 12% of total body surface area. Exclusion criteria were: unstable hemodynamic condition, inappropriate fluid loading, associated pulmonary injury, or burn injury older than 2 days. Propofol (4 mg *symbol* kg sup -1) plus fentanyl (2.5 micro gram *symbol* kg sup -1) was administered while the children were bathed and the burn area cleaned during which the children breathed spontaneously a mixture of oxygen and nitrous oxide (50:50). Venous blood samples of 300 micro liter were obtained at 5, 15, 30, 60, 90, and 120 min, and 3, 4, 8, and 12 h after injection; an earlier sample was obtained from 8 of 12 children. The blood concentration curves obtained for individual children were analyzed by three different methods: noncompartmental analysis, mixed-effects population model, and standard two-stage analysis.

Results: Using noncompartmental analysis, total clearance of propofol (+/-SD) was 0.053+/-0.013 l *symbol* kg sup -1 *symbol* min sup -1, volume of distribution at steady state 9.5+/-3.7 l *symbol* kg sup -1, and mean residence time 188+/-85 min. Propofol pharmacokinetics were best described by a weight-proportional three-compartmental model in both population and two-stage analysis. Estimated and derived pharmacokinetic parameters were similar using these two pharmacokinetic approaches. Results of population versus two-stage analysis are as follow: systemic clearance 0.049 versus 0.048 l *symbol* kg sup -1 *symbol* min sup -1, volume of central compartment 1.03 versus 0.95 l *symbol* kg sup -1, volume of distribution at steady state 8.09 versus 8.17 l *symbol* kg sup -1.     

The Importance of Hydration in Body Composition Assessment in Children Aged 6-16 Years

Body composition is associated with many noncommunicable diseases. The accuracy of many simple techniques used for the assessment of body composition is influenced by the fact that they do not take into account tissue hydration and this can be particularly problematic in paediatric populations. The aims of this study were: (1) to assess the agreement of two dual energy X-ray absorptiometry (DXA) systems for determining total and regional (arms, legs, trunk) fat, lean, and bone mass and (2) to compare lean soft tissue (LST) hydration correction methods in children. One hundred and twenty four healthy children aged between 6 and 16 years old underwent DXA scans using 2 GE healthcare Lunar systems (iDXA and Prodigy). Tissue hydration was either calculated by dividing total body water (TBW), by 4-component model derived fat free mass (HFFM_TBW) or by using the age and sex specific coefficients of Lohman, 1986 (HFFM_Lohman) and used to correct LST. Regression analysis was performed to develop cross-calibration equations between DXA systems and a paired samples t-test was conducted to assess the difference between LST hydration correction methods. iDXA resulted in significantly lower estimates of total and regional fat and lean mass, compared to Prodigy. HFFM_TBW showed a much larger age/sex related variability than HFFM_Lohman. A 2.0 % difference in LST was observed in the boys (34.5 kg vs 33.8 kg respectively, p < 0.05) and a 2.5% difference in the girls (28.2 kg vs 27.5 kg respectively, p < 0.05) when corrected using either HFFM_TBW or HFFM_Lohman. Care needs to be exercised when combining data from iDXA and Prodigy, as total and regional estimates of body composition can differ significantly. Furthermore, tissue hydration should be taken into account when assessing body composition as it can vary considerably within a healthy paediatric population even within specific age and/or sex groups.     

社区0~3岁幼儿口腔健康状况及干预策略分析

目的 分析0~3岁婴幼儿的口腔健康状况、相应的影响因素以及针对性干预策略。方法 选取 2018年5月-2020年4月于北京市丰台区新村社区卫生服务中心保健科进行体检的158名入托前婴幼儿为研究 对象,作为试验组,采用口腔健康优质管理。另选取辖区内幼儿园同年龄段幼儿158名为对照组,采用常 规口腔干预。比较两组婴幼儿的患龋率、口腔不良习惯发生率、家长口腔卫生知晓率及对口腔健康教育的 满意率。结果 试验组患龋率为6.96%,低于对照组20.25%,差异有统计学意义（P＜0.05）;试验组口腔不 良习惯发生率为9.49%,低于对照组的39.24%,差异有统计学意义（P＜0.05）;试验组家长口腔卫生知晓 率为90.51%,高于对照组的63.92%,差异有统计学意义（P＜0.05）;试验组家长对口腔健康教育的满意率 为81.65%,高于对照组的63.92%,差异有统计学意义（P＜0.05）。 结论 在本社区0~3岁幼儿中采用口腔建 档管理,同时对其家长进行有效的口腔卫生宣教等口腔健康优质管理可以有效降低婴幼儿口腔疾病的发生 率,改善儿童的口腔健康状况,提高家长对口腔卫生的知晓率,且家长对口腔健康教育的满意度较高,具 有一定的临床意义和社会价值。     

Bioavailability of Intramuscular Rocuronium in Infants and Children

Background: Intramuscular rocuronium, in doses of 1,000 micro gram/kg in infants and 1,800 micro gram/kg in children, produces complete twitch depression in 5-6 min. To determine the rate and extent of absorption of rocuronium after intramuscular administration, blood was sampled at various intervals after rocuronium administration by both intramuscular and intravenous routes to determine plasma concentrations (Cp) of rocuronium.

Methods: Twenty-nine pediatric patients ages 3 months to 5 yr were anesthetized with N2 O and halothane. The trachea was intubated, ventilation was controlled, and adductor pollicis twitch tension was measured. When anesthetic conditions were stable, rocuronium (1,000 micro gram/kg for infants and 1,800 micro gram/kg for children) was injected either intramuscularly (in the deltoid muscle) or intravenously. Four venous plasma samples were obtained from each child 2-240 min after rocuronium administration. A mixed-effects population pharmacokinetic analysis was applied to these values to determine bioavailability, absorption rate constant, and time to peak Cp with intramuscular administration.

Results: With intramuscular administration, rocuronium's bioavailability averaged 82.6% and its absorption rate constant was 0.105 min sup -1. Simulation indicated that Cp peaked 13 min after rocuronium was given intramuscularly, and that 30 min after intramuscular administration, less than 4% of the administered dose remained to be absorbed from the intramuscular depot.     

Pharmacokinetics of Rocuronium during the Three Stages of Liver Transplantation

Background: Little is known about the influence of liver transplantation on the pharmacokinetics of most anesthetic drugs. The authors determined the pharmacokinetics of rocuronium during liver transplantation and examined whether variability in pharmacokinetics could explain variability in recovery of neuromuscular function.

Methods: Twenty patients undergoing liver transplantation were given rocuronium, 600 micro gram/kg, after induction of anesthesia and again after perfusion of the transplanted liver. Plasma was sampled to determine rocuronium concentrations. Pharmacokinetic models were fit to rocuronium concentrations versus time data using a mixed-effects population approach. Various models permitted changes in clearance (Cl) or central compartment volume to account for changes in hepatic function and circulatory status during the paleohepatic, anhepatic, and neohepatic periods. Time to initial recovery of four twitches of the orbicularis oculi was determined.

Results: During the paleohepatic and anhepatic periods, the typical value of Cl was 2.47 ml [center dot] kg sup -1 [center dot] min sup -1 and was not influenced by the magnitude of preexisting liver disease (as evidenced by prothrombin time, bilirubin, serum albumin, alanine transaminase [ALT], and aspartate transaminase [AST]). During the neohepatic period, the typical value of Cl varied as a function of the duration of warm ischemia of the hepatic allograft and was 2.72 ml [center dot] kg sup -1 [center dot] min sup -1 for a patient with an average 60-min period of warm ischemia; time to neuromuscular recovery varied as a function of Cl.     

Comparison of Quantitative Ultrasound Measurements in Calcaneus with DXA and SXA at Other Skeletal Sites: A Population-Based Study on 280 Children Aged 11–16 Years

We performed ultrasound measurements (QUS) of the calcaneus in a population-based setting on 280 healthy children, aged 11–16 years, from a small urban area in southern Sweden. The results are compared with dual-energy X-ray absorptiometry (DXA) measurements in the total body, the lumbar spine and the hip, as well as single-energy X-ray absorptiometry (SXA) of the forearm. Normative data and correlations between the three different techniques were determined. We found significant correlations between QUS and age (r= 0.34–0.54), height (r= 0.13–0.56) and weight (r= 0.30–0.60), and between QUS and bone mineral density (BMD) measurements (r= 0.44–0.70). Boys increased all their bone mineral variables with age, whereas girls showed a decreasing trend from age 15 years. QUS had a significantly higher increase in standardized value with age than Ward's triangle BMD, but a significantly lower increase in standardized value with age than distal radius (cortical site) BMD. At other BMD sites we did not find any significant differences compared with QUS regarding changes with age. The measurements obtained by QUS, DXA and SXA, respectively, were divided into quartiles. Of all subjects in the lowest quartile for QUS measurements, only 34–50% were also in the lowest quartiles for DXA and SXA measurements. In conclusion, QUS measurements of the calcaneus in children show similar results as for adult regarding the correlation with DXA and SXA; they also have a significant correlation with anthropometric data. QUS did not identify the same individuals with low bone mass as the X-ray techniques. Received: 23 June 1997 / Accepted: 21 January 1998     

Fetal Growth and Blood Pressure in a Danish Population Aged 31-51 Years

During the past decade, studies have shown an inverse association between birth weight and blood pressure and risk of coronary heart disease in adult life. From old public archives we were able to trace the birth records of 545 out of 905 persons (60.2%) aged 31-51 years who participated in the Ebeltoft Health Promotion Project in Denmark. We examined the associations between birth weight, length at birth, Ponderal Index and systolic and diastolic blood pressure. No associations were found for women. For men, the mean systolic blood pressure fell from 131.1 mmHg with a birth weight of less than 3300 g to 129.6 mmHg with a birth weight of more than 4000 g, and for diastolic blood pressure 81.6 mmHg to 80.3 mmHg, respectively. For men, the mean systolic blood pressure fell from 135.7 mm Hg with a birth length of 30-51 cm to 131.6 with a birth length of 55-62 cm, and for diastolic blood pressure 83.0 mmHg to 78.8 mmHg, respectively. The associations may reflect organ programming in fetal life.     

Intramuscular Rocuronium in Infants and Children: Dose-ranging and Tracheal Intubating Conditions

Background: Rocuronium's rapid onset and intermediate duration of action with intravenous administration suggests that intramuscular administration might facilitate tracheal intubation without producing prolonged paralysis. Accordingly, in infants and children, the authors measured onset at the adductor pollicis and respiratory muscles to determine the optimal dose (phase I), then gave this optimal dose to determine the optimal time for tracheal intubation (phase II).

Methods: The authors studied 45 unpremedicated patients aged 3 months to 5 yr. In phase I, 25 patients were anesthetized with nitrous oxide and halothane and breathed spontaneously; twitch tension and minute ventilation were measured. Rocuronium (800-2,400 micro gram/kg) was injected into the quadriceps or deltoid muscle; doses varied, using an "up-down" technique, the goal being to bracket the dose depressing twitch 75-90% within 5 min. In phase II, deltoid injections of the optimal dose from phase I (infants: 1,000 micro gram/kg; children: 1,800 micro gram/kg) were given to 20 patients anesthetized with 0.82-1.0% halothane. Tracheal intubation was attempted 1.5-3.0 min later; time to tracheal intubation was varied, using an "up-down" technique.

Results: In phase I, 5 of 7 patients given quadriceps injections (1,200-2,200 micro gram/kg) had slow onset of twitch and ventilatory depression. With deltoid injections (800-2,400 micro gram/kg), all patients developed complete twitch depression; median time to 50% depression of minute ventilation was 3.2 min in infants and 2.8 min in children. In phase II, intubating conditions were consistently adequate or good-excellent at 2.5 min in infants and 3.0 min in children. Initial twitch recovery was at 57+/-13 min (mean+/-SD) in infants and 70+/-23 min in children.     

Normal Values for Tibial Quantitative Ultrasonometry in Caucasian Children and Adolescents (Aged 6 to 19 Years)

Bone densitometry in children is a relatively new topic of interest within the field of osteoporosis. Bone densitometry techniques using an X-ray source have the disadvantage of radiation exposure. Also on some systems, motion artifacts are caused by long scan times. Tibial quantitative ultrasonometry (QUS) is ideally suited for children as it is radiation free and the interactive measurement provides real-time quality control. In this prospective study, we present data from 596 healthy children—309 girls, mean age 12.9 years (range 6.1–19.9), and 287 boys, mean age 12.3 years (range 6.1–19.6) from Rotterdam, The Netherlands. For all subjects, a short questionnaire regarding overall health was completed. To assess skeletal age, an X-ray of the left hand was taken and tibial QUS of the right tibia was performed using the SoundScan™ Compact. A statistically significant correlation was found between age and speed of sound (SOS)—r² _boys= 0.52 and r² _girls= 0.63 (both P < 0.001) and between skeletal age and SOS—r² _boys= 0.56 and r² _girls= 0.63 (both P < 0.001). In boys, significant increase of mean SOS is seen between Tanner stages II and III and between IV and V. In girls there is a significant increase of mean SOS among all Tanner stages, except stages II and III. This is the first study to present normative tibial QUS data for Caucasian children and adolescents. In this study, normative data relative to skeletal age are also provided, facilitating the implementation of this technique in children with growth disorders showing dissociation between calendar and skeletal age. Received: 20 November 1998 / Accepted: 8 March 2000     

Dose-Response of Rocuronium Bromide in Children Anesthetized with Propofol: A Comparison with Succinylcholine

Background: The aim of this study was to determine the potency of rocuronium during propofol/fentanyl/N2 O anesthesia in children and to compare the time course of action of rocuronium at doses of two and three times the ED95 with that of succinylcholine.

Methods: Rocuronium (120, 160, 200, or 240 micro gram/kg) was administered to 48 children aged 2-10 yr. Neuromuscular block was assessed by monitoring the electromyographic response of the adductor digiti minimi to supramaximal stimulation of the ulnar nerve at 2 Hz for 2 s every 10 s. Potency was determined by log-probit transformation and least-squares linear regression analysis of dose and response. In a second group of 30 children, the onset and recovery profile of rocuronium at doses of two and three times the ED95 was compared with that of succinylcholine (2 mg/kg).

Results: Values for ED50 and ED95 were 210 +/- 24 and 404 +/- 135 micro gram/kg, respectively. The time to 90% neuromuscular block after 1.2 mg/kg rocuronium (three times the ED95), 33 +/- 5 s (mean +/- SD), did not differ significantly from that after succinylcholine, at 30 +/- 7 s; however, both were significantly less than that after 0.8 mg/kg rocuronium, 46 +/- 8 s (P < 0.05). The time to 25% recovery from 1.2 micro gram/kg rocuronium, 41 +/- 13 min, was approximately 50% greater than that after 0.8 mg/kg, at 27 +/- 6 min (P < 0.001), and eight times greater than that after succinylcholine, at 5.2 +/- 1.9 min (P < 0.001).     

Bronchial Hyperresponsiveness to Methacholine in Children Under 4 Years with Recurrent Bronchitis

ObjectiveTo evaluate bronchial hyperresponsiveness in children under 4 years old with recurrent wheezing bronchitis, and to determine if its presence or absence can predict subsequent progression to a transient or persistent wheezing bronchitis phenotype.Population and methodsA bronchial challenge test was performed with methacholine using a modified tidal volume method without sedation, in a group of patients from 8 to 47 months of age with recurrent wheezing bronchitis and a control group of healthy children. A decrease in oxygen saturation of ≥5% or an increase in respiration rate of >50% [PCwheeze (PCw)] was considered a positive response. The patients were subsequently clinically followed up to assess their progress.ResultsA total of 63 patients and 16 controls were studied (mean age 23.9 compared to 25.2 months). The PCw in 43 (68%) children from the bronchitis group was lower than the control group (≤4 mg/mL), (P<.001). No significant adverse effects were observed on performing the test. After a mean follow-up of 28.5 months, completed in 49 of the patients, no differences were seen between the presence of bronchial hyperresponsiveness at the beginning of the study and the subsequent progression to transient, infrequent or frequent wheezing (P=.63).ConclusionsA high percentage of children under 4 years old with wheezing bronchitis had a bronchial hyperresponse. Subsequent progression to transient or persistent wheezing bronchitis phenotype is not associated with bronchial hyperresponsiveness.     

Exhaled Nitric Oxide in Children Under 4 Years of Age With Recurrent Bronchitis

BackgroundThe objective of the study was to assess bronchial inflammation in preschool children with recurrent bronchitis by measuring exhaled nitric oxide.Patients and MethodsThe study included patients under 4 years of age with at least 3 episodes of wheezing in the past year (n=63) and a control group (n=30). Exhaled nitric oxide was measured in samples collected offline during spontaneous tidal breathing with a face mask and stored in Mylar balloons.ResultsThe fractional exhaled nitric oxide concentration (FE_NO) was higher in the group with bronchitis (mean [SD], 5.3 [1.3] parts per billion [ppb]) than in the control group (4.6 [1.1] ppb) (P=.02). There was a significant difference between the control group and children in the bronchitis group not treated with inhaled corticosteroids (P<.05), but not between controls and corticosteroid-treated patients. A relationship with eosinophil count was observed in that those with higher counts (>400 mL) had higher FE_NO levels (P<.01). No relationship was observed between FE_NO and a positive methacholine challenge test. Follow-up lasted at least 20 months. The initial FE_NO level did not differ significantly according to whether patients were subsequently transient, infrequent, or frequent wheezers (5.2 [0.98] ppb, 5.6 [1.5] ppb, and 4.8 [1.34] ppb, respectively; P=.36).ConclusionsIn children under 4 years of age with recurrent wheezing bronchitis who were asymptomatic at study entry, a small increase in FE_NO was observed although there was a good deal of overlap with the control group.     

Laparoscopic Cholecystectomy in Patients Aged 80 Years and Over

Introduction The aging population has led to a significant rise in the number of patients undergoing operations such as cholecystectomy. We have evaluated and compared the results of laparoscopic cholecystectomy (LC) in patients aged 80 years and over with those of patients aged between 65 and 79 years. Methods A total of 471 patients aged 65 to 79 years (group 1) and 45 patients aged ≥80 years (group 2) underwent LC. All patients underwent preoperative spiral computed tomography after intravenous infusion cholangiography and intraoperative cholangiography. Results There was a higher incidence of choledocholithiasis and gallbladder cancer in the patients ≥80 years of age. In addition, group 2 patients had a higher incidence of cardiopulmonary disease and higher American Association of Anesthesiology scores than did those in group 1. With respect to the conversion rate to open surgery, morbidity, mortality, and length of hospital stay, there were no significant differences between the two groups. There was a significantly higher incidence of positive bile cultures and gram-negative rods in group 2 patients than in those in group 1. Conclusions Octogenarians tolerated LC well. Therefore, early elective LC should be encouraged to minimize morbidity and mortality in these elderly patients who have symptomatic cholelithiasis.     

Skin Tumors in Patients Aged 90 Years and Older

BACKGROUND: The aging of the population in the developed world is an accepted fact. Consequently, the number of patients aged 90 years or over with cutaneous cancer will increase in coming years. OBJECTIVE: The objective was to determine the nature of skin lesions amenable to dermatologic surgery in patients aged 90 years or more. METHODS: We studied the clinical histories of 52 outpatients in their 90 s, who had had histopathologic studies made of their skin tumors when attended in the Hospital General de Alicante (Spain) between January 1999 and July 2002. We studied sex, age, type of tumor, site, associated disorders, regular medications, type of anesthesia, and type of treatment given. RESULTS: The average age of the patients was 92.4 years. Thirty-six patients were women and 16 were men. Altogether the 52 patients had a total of 72 lesions. The most frequent diagnosis was basal cell carcinoma with 36 lesions, followed by 20 squamous cell carcinomas. The overall ratio of basal cell carcinoma to squamous cell carcinoma was 1.8. Patients had an average of 1.5 comorbid medical conditions and were taking an average of 2.3 regular medications. CONCLUSION: Dermatologists often attend patients aged 90 years or over with nonmelanoma skin cancer. The most important decision is as to what is the best management of these patients.