Pediatric Patients Of Different Ages Research Articles

Efficacy and Safety of SPN-812 (Extended-Release Viloxazine) in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis.

SPN-812 has been approved for attention-deficit/hyperactivity disorder (ADHD) treatment in children and adolescents. We aimed to analyze the efficacy and safety of different doses of SPN-812 for ADHD pediatric patients of different ages, verify its clinical efficacy, and evaluate its safety. Up until 30 August 2023, randomized controlled trials (RCTs) were searched in EMBASE, MEDLINE, the Cochrane Library, and clinicaltrials.gov to evaluate different doses of SPN-812 and a placebo. We pooled 1619 patients from five RCTs with a duration of 6-8 weeks. Patients (6-17 years old) in SPN-812 (100, 200, and 400 mg/d) groups were superior to the control group in all efficacy outcomes with lower attention-deficit/hyperactivity disorder rating scale-5 (ADHD-RS-5), Conners 3-parent short form composite T score (Conners 3-PS), Weiss functional impairment rating scale-parent (WFIRS-P), and increased clinical global impression-improvement (CGI-I) score (both p < 0.05). At the same time, only SPN-812 300 mg/d did not show a significantly high risk of the adverse events (AEs) such as somnolence and decreased appetite (p = 0.09). There was no significant difference between placebo and SPN-812 groups (100, 200, and 400 mg/d) in serious adverse events (SAEs) such as syncope. The subgroup analyses showed that, both in children and adolescents subgroups, SPN-812 showed better efficacy than the placebo. The two age subgroups showed a significantly higher risk of AEs and an insignificant risk of SAEs than the placebo. At present, SPN-812 (100, 200, and 400 mg/d) is superior to the corresponding control in efficacy measures. However, the safety problem cannot be ignored.

Značaj farmakokinetike u doziranju lekova kod pedijatrijskih pacijenata

Optimizing the dosing of medicines for pediatric patients in routine clinical practice and determining the dose for clinical trials is still a challenging task. Children differ from adults in their response to drugs due to inherent differences in pharmacokinetics and/or pharmacodynamics, and responses may also vary among pediatric patients of different ages. However, the greatest disparities compared to adult pharmacokinetic profiles are observed in children below 2 years of age. The maturation of the liver and the kidneys, as well as the variation in body composition, are considered to be the main sources of pharmacokinetic variability. Hence, besides specific pharmacodynamic features, understanding age-related changes in drug absorption, distribution, and elimination is fundamental for optimizing drug efficacy and avoiding toxicity. This paper summarizes the pharmacokinetic changes throughout the childhood, along with the effect of developmental changes on drug dosage calculation. In clinical practice, age and body weight-based dosing regimens are usually used. In spite of dosing recommendations based on age and/or body weight, variabilities in pharmacokinetics and pharmacodynamic response remain, implying a need to monitor patients and optimize the dosing regimen according to physiological characteristics, disease characteristics and therapy.

301 Understanding Emergency Medical Services Provider Comfort and Education in Caring for Pediatric Patients

Protocols for the transfer and stabilization of pediatric patients with life-threatening emergencies vary across age groups and differ significantly from adults. The present survey study aims to assess emergency medical services (EMS) provider comfort in treating pediatric patients of different ages and presenting illnesses and better understand how continuing education affects comfort level. Results from the study are intended to advocate for strengthening pediatric education curricula within departments and continuing education guidelines at a state and national level.

Does Device Selection Impact Recanalization Rate and Neurological Outcome?: An Analysis of the Save ChildS Study.

Background and Purpose- The recent Save ChildS study provides multicenter evidence for the use of mechanical thrombectomy in children with large vessel occlusion arterial ischemic stroke. However, device selection for thrombectomy may influence rates of recanalization, complications, and neurological outcomes, especially in pediatric patients of different ages. We, therefore, performed additional analyses of the Save ChildS data to investigate a possible association of different thrombectomy techniques and devices with angiographic and clinical outcome parameters. Methods- The Save ChildS cohort study (January 2000-December 2018) analyzed data from 27 European and United States stroke centers and included all pediatric patients (<18 years), diagnosed with arterial ischemic stroke who underwent endovascular recanalization. Patients were grouped into first-line contact aspiration (A Direct Aspiration First Pass Technique [ADAPT]) and non-ADAPT groups as well as different stent retriever size groups. Associations with baseline characteristics, recanalization rates (modified Treatment in Cerebral Infarction), complication rates, and neurological outcome parameters (Pediatric National Institutes of Health Stroke Scale after 24 hours and 7 days; modified Rankin Scale and Pediatric Stroke Outcome Measure at discharge, after 6 and 24 months) were investigated. Results- Seventy-three patients with a median age of 11.3 years were included. Currently available stent retrievers were used in 59 patients (80.8%), of which 4×20 mm (width×length) was the most frequently chosen size (36 patients =61%). A first-line ADAPT approach was used in 7 patients (9.6%), and 7 patients (9.6%) were treated with first-generation thrombectomy devices. In this study, a first-line ADAPT approach was neither associated with the rate of successful recanalization (ADAPT 85.7% versus 87.5% No ADAPT) nor with the complication rate or the neurological outcome. Moreover, there were no associations of stent retriever sizes with rates of recanalization, complication rates, or outcome parameters. Conclusions- Our study suggests that neurological outcomes are generally good regardless of any specific device selection and suggests that it is important to offer thrombectomy in eligible children regardless of technique or device selection. Registration- URL: https://www.drks.de/; Unique identifier: DRKS00016528.

Current pediatric administered activity guidelines for 99m Tc-DMSA SPECT based on patient weight do not provide the same task-based image quality.

In the current clinical practice, administered activity (AA) for pediatric molecular imaging is often based on the North American expert consensus guidelines or the European Association of Nuclear Medicine dosage card, both of which were developed based on the best clinical practice. These guidelines were not formulated using a rigorous evaluation of diagnostic image quality (IQ) relative to AA. In the guidelines, AA is determined by a weight-based scaling of the adult AA, along with minimum and maximum AA constraints. In this study, we use task-based IQ assessment methods to rigorously evaluate the efficacy of weight-based scaling in equalizing IQ using a population of pediatric patients of different ages and body weights. A previously developed projection image database was used. We measured task-based IQ, with respect to the detection of a renal functional defect at six different AA levels (AA relative to the AA obtained from the guidelines). IQ was assessed using an anthropomorphic model observer. Receiver-operating characteristics (ROC) analysis was applied; the area under the ROC curve (AUC) served as a figure-of-merit for task performance. In addition, we investigated patient girth (circumference) as a potential improved predictor of the IQ. The data demonstrate a monotonic and modestly saturating increase in AUC with increasing AA, indicating that defect detectability was limited by quantum noise and the effects of object variability were modest over the range of AA levels studied. The AA for a given value of the AUC increased with increasing age. The AUC vs AA plots for all the patient ages indicate that, for the current guidelines, the newborn and 10- and 15-yr phantoms had similar IQ for the same AA suggested by the North American expert consensus guidelines, but the 5- and 1-yr phantoms had lower IQ. The results also showed that girth has a stronger correlation with the needed AA to provide a constant AUC for 99m Tc-DMSA renal SPECT. The results suggest that (a) weight-based scaling is not sufficient to equalize task-based IQ for patients of different weights in pediatric 99m Tc-DMSA renal SPECT; and (b) patient girth should be considered instead of weight in developing new administration guidelines for pediatric patients.

Children Are Not Small Adults, but Can We Treat Them AsSuch?

Although children cannot be considered small adults due to nonlinear processes underlying the pharmacokinetics of drugs, pediatric doses are typically still expressed per kilogram. We use a physiologically based pharmacokinetic (PBPK) workflow to assess the accuracy of linear scaling of plasma clearance (CLp) for hypothetical drugs with ranges of realistic parameter values in pediatric patients of different ages. The results are compared with 0.75 fixed allometric scaling (AS 0.75). Linear CLp scaling is accurate down to the age of 1 month for drugs undergoing glomerular filtration, except when these drugs are highly bound to alpha‐1‐acid glycoprotein (AGP). For hepatically cleared drugs, linear scaling is reasonably accurate down the age of 2 years, except for AGP‐bound drugs with a low extraction ratio and mature isoenzymes. In neonates, linear scaling outperforms AS 0.75 for human serum albumin (HSA) and AGP‐bound drugs excreted through glomerular filtration. These results suggest that pediatric patients can, in many cases, be treated as small adults.

Comparison of conservative treatment outcomes for proximal humeral epiphyseal fractures in patients of different ages.

Several studies have suggested that excellent therapeutic outcomes can be achieved with conservative treatment of proximal humeral epiphyseal fractures in patients younger than 11years old; however, the outcomes of conservative treatment for children older than 11years are controversial. To address this problem, this study compared outcomes of conservative treatment for proximal humeral epiphyseal fractures in pediatric patients of different ages. The patients were divided into two groups for comparative purposes based on age. GroupI consisted of 34patients who were less than 11years old (average age: 5years) and groupII included 21patients who were 11years of age or older (average age: 14years). Patients in both groups underwent conservative treatment and follow-up examination, where they first were examined with X‑radiography for assessment of deformity, fracture union and loss of reduction. At the final follow-up after 2years, patients were assessed by an interview and adetailed physical examination including the assessment of shoulder function using the Constant-Murley score. There were no significant differences in the grading scale of varus deformity between the two groups (P > 0.05) after immediate postreduction X‑radiography; however, there were significant differences in the grading scale of varus deformity between groupI and groupII at the 2‑year follow-up (P < 0.05). There were no significant differences between the two groups with respect to the Constant-Murley score and arm length discrepancy (P > 0.05) at final follow-up examinations. In general, the results suggested that the outcomes, as measured with radiographs, for both older and young children were comparable after immediate postreduction roentgenograms. For long-term follow-up there was adifference between the two groups and the degree of angulation and displacement might be associated with treatment outcomes for older children. Thus, these factors should be considered when treating and evaluating the outcomes for older children.

Epidemiological investigation on 1 946 hospitalized pediatric patients with burns

Objective: To investigate the epidemiological characteristics of hospitalized pediatric patients with burns and explore the prevention and treatment strategy of pediatric burns. Methods: Medical records of pediatric burn patients hospitalized in multiple departments of Children's Hospital of Chongqing Medical University from January 2012 to December 2016 were retrospectively analyzed. Data including gender, age, residence, ways of paying, total burn area, burn severity, cause, time, and place of burns, prehospital treatment ways, clinical outcome, length of hospital stay were collected and processed with chi-square test, Kruskal-Wallis H test, and Bonferroni correction. The factors which influence wound healing were processed with multivariate logistic regression analysis. Results: (1) A total of 1 946 pediatric burn patients with complete medical records were hospitalized in Children's Hospital of Chongqing Medical University during the 5 years, with 1 127 boys (57.91%), which were more than 819 girls (42.09%). Pediatric patients≤3 years old were with the highest incidence of burns of 87.15% (1 696/1 946). There was no significantly statistical difference in gender composition ratio among pediatric patients of different ages (χ2=2.294, P= 0.318). (2) The residence of 1 536 pediatric patients (78.93%) were in town, and most of them used urban resident essential medical insurance for medical cost. Most of the pediatric patients living in rural areas paid the medical cost at their own expense. There was significantly statistical difference in way of paying between pediatric patients living in urban and those in rural areas (χ2=658.324, P<0.05). (3) The pediatric patients with total burn surface area≥5% total body surface area (TBSA) and<15% TBSA were the most (1 200 cases, accounting for 61.66%). The pediatric patients with moderate burns were the most (1 225 cases, accounting for 62.95%), followed by mild burns (494 cases, accounting for 25.39%), severe burns (124 cases, accounting for 6.37%), and extremely severe burns (46 cases, accounting for 2.36%). (4) The pediatric patients with scald caused by hot water were the most (1 801 cases, accounting for 92.55%), followed by flame burns (69 cases, accounting for 3.55%), chemical burns (44 cases, accounting for 2.26%), and electrical burns (32 cases, accounting for 1.64%). There was significantly statistical difference in cause of injury among pediatric patients of different ages (χ2=85.471, P<0.05). (5) The incidence of burns of pediatric patients in Spring was 27.95% (544/1 946), which was slightly higher than those in other seasons. There was significantly statistical difference in the burn season among pediatric patients admitted to the hospital in different years (χ2= 23.172, P< 0.05). As to burn place, most of burns of pediatric patients happened at home (1 776 cases, accounting for 91.26%). (6) There was significantly statistical difference in clinical outcome among pediatric patients with different prehospital treatments (H=16.005, P<0.05). There was significantly statistical difference in clinical outcome between pediatric patients with reasonable prehospital treatments and those with unreasonable prehospital treatments (H=-64.990, P<0.05), and between pediatric patients with reasonable prehospital treatments and those without any treatment (H=-74.775, P<0.05). There was no significantly statistical difference in clinical outcome between pediatric patients with unreasonable prehospital treatments and those without any prehospital treatment (H=-9.785, P>0.05). (7) The median of length of hospital stay of pediatric patients was 8 days. The pediatric patients with length of hospital stay≤7 days were the most (834 cases, accounting for 42.86%), and the pediatric patients with length of hospital stay>30 days were the least (39 cases, accounting for 2.00%). (8) The way of prehospital treatment and cause of injury were independent risk factors influencing wound healing (χ2=7.946, 12.977, P<0.05). With no prehospital treatment as benchmark, reasonable prehospital treatments promoted wound healing (odds ratio=1.662, 95% confidence interval=1.129-2.447, P<0.05). With chemical burns as benchmark, electrical burn wounds were harder to heal (odds ratio=0.144, 95% confidence interval=0.028-0.734, P<0.05). Conclusions: Pediatric burn patients hospitalized in Children's Hospital of Chongqing Medical University were mainly boys≤3 years old with moderate scald caused by hot water at home in urban areas. Timely and reasonable prehospital treatments are beneficial to wound healing.

Comparison of efficacy of propofol given by closed-loop infusion for surgery in pediatric patients of different ages

Objective To compare the efficacy of closed-loop infusion of propofol for surgery in pediatric patients of different ages. Methods Forty-five pediatric patients of both sexes, weighing 10-63 kg, of American Society of Anesthesiologists physical statusⅠ or Ⅱ, scheduled for elective urologic surgery under general anesthesia, were divided into 3 groups (n=15 each) according to the age: infant group (1-3 yr), pre-school group (4-6 yr) and school-age group (7-12 yr). The bispectral index (BIS) monitor was connected to the closed-loop anesthesia delivery system, and the system automatically regulated the target plasma concentration of propofol to achieve a target BIS value of 45-55 during maintenance of anesthesia.Remifentanil was given by target-controlled infusion at a target plasma concentration and rocuronium was intravenously injected when necessary during surgery.BIS40-60 time percentage (percentage of time of BIS value maintaining at 40-60 in time of closed-loop infusion), median performance error (MDPE), median absolute performance error (MDAPE), wobble and global score were recorded.The consumption of propofol, mean target plasma concentration and regulating frequency and consumption of remifentanil and rocuronium were recorded during surgery.Extubation time or laryngeal mask airway removal time, time to eye-opening and time of regaining consciousness were recorded. Results The BIS40-60 time percentage was significantly higher, MDPE, MDAPE, wobble and global score were lower in pre-school and school-age groups than in infant group (P 0.05). There was no significant difference in the consumption of propofol, mean target plasma concentration, regulating frequency, consumption of rocuronium, extubation time or laryngeal mask airway removal time, time to eye-opening or time of regaining consciousness among the 3 groups (P>0.05). Conclusion Closed-loop infusion of propofol produces better stability for surgery in pre-school and school-age children than in infants. Key words: Propofol; Drug dilivery systems; Child

Neurotoxic manifestations of black widow spider envenomation in paediatric patients

IntroductionEnvenomation by black widow spiders manifests clinically with signs of neurotoxicity in paediatric patients. ObjectiveIdentify typical neurological signs and symptoms in paediatric patients of different ages, and describe treatment and outcomes in a paediatric hospital in northwest Mexico. Material and methodsWe reviewed 70 clinical records of patients hospitalised due to black widow spider bite between 1978 and 2014. We divided the total into 2 groups: Group 1, infants and preschool children; and Group 2, school-age children and adolescents. The demographic variables were age, sex, birthplace, place where envenomation occurred, body part(s) affected, degree of envenomation according to signs and symptoms, treatment, clinical outcome, and statistical differences. ResultsBoys accounted for 61.4% of all cases, and infants younger than one year made up 14.2%. Most patients (70%) were bitten by the spider at home; the anatomical areas most frequently affected were the legs, neck, thorax, and abdomen. The neurological signs and symptoms displayed by Group 1 were irritability, constant crying, sialorrhoea, nausea, tachycardia, arrhythmias, fatigue when walking, agitation, muscle spasms paraesthesia, tetany, seizures, and nystagmus. Signs in Group 2 included localised pain, headache, sialorrhoea, paraesthesia, profuse sweating, anxiety, muscle weakness, muscle spasms, and fine tremor. The predominant autonomic sign in Group 1 was sialorrhoea (P<.0001) and in Group 2, paraesthesia (P<.0001). Patients who received Fab antivenom treatment displayed better outcomes and shorter hospital stays than those who did not. No deaths were reported. ConclusionsThe neurological signs and symptoms caused by black widow spider bite are predominantly autonomic, and identifying them permits early diagnosis and more effective treatment.

Manifestaciones de neurotoxicidad en el envenenamiento por mordedura de araña «viuda negra» en edades pediátricas

IntroductionEnvenomation by black widow spiders manifests clinically with signs of neurotoxicity in paediatric patients. ObjectiveIdentify typical neurological signs and symptoms in paediatric patients of different ages, and describe treatment and outcomes in a paediatric hospital in northwest Mexico. Material and methodsWe reviewed 70 clinical records of patients hospitalised due to black widow spider bite between 1978 and 2014. We divided the total into 2 groups: Group 1, infants and preschool children; and Group 2, school-age children and adolescents. The demographic variables were age, sex, birthplace, place where envenomation occurred, body part(s) affected, degree of envenomation according to signs and symptoms, treatment, clinical outcome, and statistical differences. ResultsBoys accounted for 61.4% of all cases, and infants younger than one year old made up 14.2%. Most patients (70%) were bitten by the spider at home; the anatomical areas most frequently affected were the legs, neck, thorax, and abdomen. The neurological signs and symptoms displayed by Group 1 were irritability, constant crying, sialorrhoea, nausea, tachycardia, arrhythmias, fatigue when walking, agitation, muscle spasms paraesthesia, tetany, seizures, and nystagmus. Signs in Group 2 included localized pain, headache, sialorrhoea, paraesthesia, profuse sweating, anxiety, muscle weakness, muscle spasms, and fine tremor. The predominant autonomic sign in Group 1 was sialorrhoea (P<.0001) and in Group 2, paraesthesia (P<.0001). Patients who received Fab antivenom treatment displayed better outcomes and shorter hospital stays than those who did not. No deaths were reported. ConclusionsThe neurological signs and symptoms caused by black widow spider bite are predominantly autonomic, and identifying them permits early diagnosis and more effective treatment

Daptomycin in paediatrics: current knowledge and the need for future research.

To overcome the problems stemming from antimicrobial resistance, there have been several attempts to develop new antimicrobials in recent years. Of the highly potent drugs targeting resistant Gram-positive bacteria, daptomycin has a number of attractive characteristics that suggest its possible use in the treatment of serious infections due to these organisms. Although several pharmacokinetic and clinical studies in adults have provided data to determine how this drug should be prescribed to obtain the maximal clinical efficacy without significant risks of severe adverse events, we have not yet solved all of the problems related to the use of this antibiotic in paediatric patients. In this paper, the resolved and lingering problems of daptomycin treatment in newborns and children are reviewed and discussed. Studies have indicated that daptomycin is a promising therapeutic option for the treatment of paediatric diseases caused by MDR Gram-positive bacilli. However, before daptomycin can be licensed for use in newborns and children, further studies are needed to establish the appropriate dosages for paediatric patients of different ages. The data collected in adults can only be transferred to children older than 12 years, and the information available is not sufficient to determine the dosage that will assure the highest antimicrobial efficacy with only marginal risks of adverse events in younger patients. Thus, studies in neonates and younger infants are urgently needed to permit the use of daptomycin in the first months of life, a period in which infections due to MDR Gram-positive pathogens are increasing.

Predicting diurnal and sleep/wake seizure patterns in paediatric patients of different ages

To identify factors that influence diurnal and sleep/wake seizure timing in children undergoing tapered drug withdrawal in an epilepsy monitoring unit. Medical charts of patients that underwent video-EEG were reviewed. Seizures were evaluated based on their occurrence in three-hour time intervals (bins) and between wakefulness and sleep. Patients were classified according to EEG localisation and age: infants (≤3 years), children (3-12 years), and adolescents (>12-21 years). Analysis utilising generalised estimating equations with a negative binomial distribution was performed. A total of 390 patients (188 girls; mean age: 9.2 years; SD: 6.0) had 1,754 seizures. Generalised seizures (109 patients; 490 seizures) occurred more during wakefulness (p<0.001) and during the day (p<0.001). Modelling revealed a greater occurrence of seizures at night with increasing age (p=0.046). Temporal lobe seizures (62 patients; 271 seizures) occurred overall more frequently during wakefulness (p=0.03). Frontal lobe seizures (41 patients; 184 seizures) occurred more frequently during wakefulness in infants (p<0.05) and more frequently during sleep in adolescents (p<0.0001). Adolescents with frontal lobe seizures were 3.6 times more likely to have seizures during sleep compared to other children (95% CI: 1.8-7.2). These findings are suggestive of changes in circadian rhythmicity that may alter seizure susceptibility in different age groups. The results may assist in prediction of periods of greatest seizure propensity.

Conference Scene: Pediatric Pharmacogenomics and Personalized Medicine

A major challenge for clinicians, pharmaceutical companies and regulatory agencies is to better understand the relative contributions of ontogeny and genetic variation to observed variability in drug disposition and response across the pediatric age spectrum from preterm and term newborns, to infants, children and adolescents. Extrapolation of adult experience with pharmacogenomics and personalized medicine to pediatric patients of different ages and developmental stages, is fraught with many challenges. Compared with adults, pediatric pharmacogenetics and pharmacogenomics involves an added measure of complexity as variability owing to developmental processes, or ontogeny, is superimposed upon genetic variation. Furthermore, some pediatric diseases have no adult correlate or are more prevalent in children compared with adults, and several adverse drug reactions are unique to children, or occur at a higher frequency in children. The primary objective of this conference was to initiate an ongoing series of annual meetings on ‘Pediatric Pharmacogenomics and Personalized Medicine’ organized by the Center for Personalized Medicine and Therapeutic Innovation and Division of Clinical Pharmacology and Medical Therapeutics at Children’s Mercy Hospitals and Clinics in Kansas City, MO, USA. The primary goals of the inaugural meeting were: to bring together clinicians, basic and translational scientists and allied healthcare practitioners, and engage in a multi- and cross-disciplinary dialog aimed at implementing personalized medicine in pediatric settings; to provide a forum for the presentation and the dissemination of research related to the application of pharmacogenomic strategies to investigations of variability of drug disposition and response in children; to explore the ethical, legal and societal implications of pharmacogenomics and personalized medicine that are unique to children; and finally, to create networking opportunities for stimulating discussion, cooperation and collaboration to devise strategies to address the research needs identified.

Pharmacokinetics and effects of propofol 6% for short-term sedation in paediatric patients following cardiac surgery.

This paper describes the pharmacokinetics and effects of propofol in short-term sedated paediatric patients. Six mechanically ventilated children aged 1-5 years received a 6 h continuous infusion of propofol 6% at the rate of 2 or 3 mg kg-1 h-1 for sedation following cardiac surgery. A total of seven arterial blood samples was collected at various time points during and after the infusion in each patient. Pharmacokinetic modelling was performed using NONMEM. Effects were assessed on the basis of the Ramsay sedation score as well as a subjective sedation scale. The data were best described by a two-compartment pharmacokinetic model. In the model, body weight was a significant covariate for clearance. Pharmacokinetic parameters in the weight-proportional model were clearance (CL) = 35 ml kg-1 min-1, volume of central compartment (V1) = 12 l, intercompartmental clearance (Q) = 0.35 l min-1 and volume of peripheral compartment (V2) = 24 l. The interindividual variabilities for these parameters were 8%, < 1%, 11% and 35%, respectively. Compared with the population pharmacokinetics in adults following cardiac surgery and when normalized for body weight, statistically significant differences were observed the parameters CL and V1 (35 vs 29 ml kg-1 min-1 and 0.78 vs 0.26 l kg-1P < 0.05), whereas the values for Q and V2 were similar (23 vs 18 ml kg-1 min-1 and 1.6 vs 1.8 l kg-1, P > 0.05). In children, the percentage of adequately sedated patients was similar compared with adults (50% vs 67%) despite considerably higher propofol concentrations (1.3 +/- 0.10 vs 0.51 +/- 0.035 mg l-1, mean +/- s.e. mean), suggesting a lower pharmacodynamic sensitivity to propofol in children. In children aged 1-5 years, a pharmacokinetic model for propofol was described using sparse data. In contrast to adults, body weight was a significant covariate for clearance in children. The model may serve as a useful basis to study the role of covariates in the pharmacokinetics and pharmacodynamics of propofol in paediatric patients of different ages.

Dosimetry of swallowed non absorbed99mTc radiopharmaceuticals in pediatric patients

A calculation is presented which derives the absorbed dose experienced by pediatric patients of different ages who swallow a non absorbable 99mTc compound. All previous models assume sudden movement of radionuclide from one compartment of the gastrointestinal tract to another. The present model is novel in considering continuous distal motion through the gut and so more closely approximates the physiologic situation. Published S values are used to derive absorbed doses. The resulting calculated absorbed doses are comparable to, or lower than, those previously published and these differences are most marked in the large gut, which remains the critical organ.