Modeling the effects of anesthesia on the electroencephalogram

Changes to the electroencephalogram (EEG) observed during general anesthesia are modeled with a physiological mean field theory of electrocortical activity. To this end a parametrization of the postsynaptic impulse response is introduced which takes into account pharmacological effects of anesthetic agents on neuronal ligand-gated ionic channels. Parameter sets for this improved theory are then identified which respect known anatomical constraints and predict mean firing rates and power spectra typically encountered in human subjects. Through parallelized simulations of the eight nonlinear, two-dimensional partial differential equations on a grid representing an entire human cortex, it is demonstrated that linear approximations are sufficient for the prediction of a range of quantitative EEG variables. More than 70 000 plausible parameter sets are finally selected and subjected to a simulated induction with the stereotypical inhaled general anesthetic isoflurane. Thereby 86 parameter sets are identified that exhibit a strong “biphasic” rise in total power, a feature often observed in experiments. A sensitivity study suggests that this “biphasic” behavior is distinguishable even at low agent concentrations. Finally, our results are briefly compared with previous work by other groups and an outlook on future fits to experimental data is provided.

Clinical predictors of response to cognitive-behavioural therapy in pediatric anxiety disorders: the Genes for Treatment (GXT) Study

Objective The Genes for Treatment study is an international, multisite collaboration exploring the role of genetic, demographic, and clinical predictors in response to cognitive-behavioral therapy (CBT) in pediatric anxiety disorders. The current article, the first from the study, examined demographic and clinical predictors of response to CBT. We hypothesized that the child’s gender, type of anxiety disorder, initial severity and comorbidity, and parents’ psychopathology would significantly predict outcome. Method A sample of 1,519 children 5 to 18 years of age with a primary anxiety diagnosis received CBT across 11 sites. Outcome was defined as response (change in diagnostic severity) and remission (absence of the primary diagnosis) at each time point (posttreatment, 3-, 6-, and/or 12-month follow-up) and analyzed using linear and logistic mixed models. Separate analyses were conducted using data from posttreatment and follow-up assessments to explore the relative importance of predictors at these time points. Results Individuals with social anxiety disorder (SoAD) had significantly poorer outcomes (poorer response and lower rates of remission) than those with generalized anxiety disorder (GAD). Although individuals with specific phobia (SP) also had poorer outcomes than those with GAD at posttreatment, these differences were not maintained at follow-up. Both comorbid mood and externalizing disorders significantly predicted poorer outcomes at posttreatment and follow-up, whereas self-reported parental psychopathology had little effect on posttreatment outcomes but significantly predicted response (although not remission) at follow-up. Conclusion SoAD, nonanxiety comorbidity, and parental psychopathology were associated with poorer outcomes after CBT. The results highlight the need for enhanced treatments for children at risk for poorer outcomes.

Emotion perception and talker discrimination in pediatric hearing aid users

The primary goal of this study is to examine the ability of pediatric hearing-aid listeners, with mild to moderately-severe hearing loss, to perceive emotion and to discriminate talkers. These listeners’ performance is compared to that of similarly-aged listeners with normal hearing and who use cochlear implants.

Speech perception and localization abilities in pediatric bilateral sequential cochlear implant recipients

The primary purpose of this study was to evaluate speech perception and localization abilities in children who have received sequential cochlear implants, with the first implant received before age 4 and the second implant received before age 12. Results indicate performance in the bilateral cochlear implant condition is significantly better than listening with each implant alone for the outcome measures used in this study.

Oral colonization by Candida species in AIDS pediatric patients

The aim of this study was to assess the prevalence of factors associated with oral colonization by Candida spp. in pediatric patients with AIDS. The sample comprised of 117 children. Clinical status, medicines in use, and laboratory findings were obtained from hospital records; sociodemographic data were given by relatives. A dental examination assessed the prevalence of dental caries. The prevalence of oral colonization by Candida was 62%. Only seven children presented clinical manifestation of oral candidosis despite their high viral load index and low-for-age CD4 count. Candida colonization was directly associated with frequent use of antibiotics (prevalence ratio [PR] = 1.44), sulfa drugs (PR = 1.23), alteration in the oral mucosa (PR = 1.55), and untreated dental caries (PR = 1.93). It was inversely associated with the use of antiretroviral therapies (PR = 0.65). Candida albicans was the most frequently detected species (80%); phenotypic tests did not detect C. dubliniensis strains. This study observed a low prevalence of Candida-related oral lesions in these patients, which is compatible with the hypothesis that antiretroviral medicines may have contributed to reducing oral manifestations from Candida infection. The high prevalence of Candida colonization in HIV+/AIDS children with untreated dental caries reinforces the importance of oral health care in interdisciplinary health units that assist these patients.

End-of-life practices in seven Brazilian pediatric intensive care units

Objective: To evaluate the incidence of life support limitation and medical practices in the last 48 hrs of life of children in seven Brazilian pediatric intensive care units (PICUs). Design. Cross-sectional multicenter retrospective study based on medical chart review. Setting: Seven PICUs belonging to university and tertiary hospitals located in three Brazilian regions: two in Porto Alegre (southern region), two in Sao Paulo (southeastern region), and three in Salvador (northeastern region). Patients. Medical records of all children who died in seven PICUs from January 2003 to December 2004. Deaths in the first 24 hrs of admission to the PICU and brain death were excluded. Interventions: Two pediatric intensive care residents from each PICU were trained to fill out a standard protocol (K = 0.9) to record demographic data and all medical management provided in the last 48 hrs of life (inotropes, sedatives, mechanical ventilation, full resuscitation maneuvers or not). Student`s t-test, analysis of variance, chi-square test, and relative risk were used for comparison of data. Measurements and Main Results. Five hundred and sixty-one deaths were identified; 97 records were excluded (61 because of brain death and 36 due to <24 hrs in the PICU). Thirty-six medical charts could not be found. Cardiopulmonary resuscitation was performed in 242 children (57%) with a significant difference between the southeastern and northeastern regions (p =.0003). Older age (p = .025) and longer PICU stay (p = .001) were associated with do-not-resuscitate orders. In just 52.5% of the patients with life support limitation, the decision was clearly recorded in the medical chart. No ventilatory support was provided in 14 cases. Inotropic drug infusions were maintained or increased in 66% of patients with do-not-resuscitate orders. Conclusions. The incidence of life support limitation has increased among Brazilian PICUs but with significant regional differences. Do-not-resuscitate orders are still the most common practice, with scarce initiatives for withdrawing or withholding life support measures.

Entrance surface dose measurements in pediatric radiological examinations

A survey of pediatric radiological examinations was carried out in a reference pediatric hospital of the city of Sao Paulo. in order to investigate the doses to children undergoing conventional X-ray examinations. The results showed that the majority of pediatric patients are below 4 years, and that about 80% of the examinations correspond to chest projections. Doses to typical radiological examinations were measured in vivo with thermoluminescent dosimeters (LiF: Mg, Ti and LiF: Mg, Cu, P) attached to the skin of the children to determine entrance surface dose (ESD). Also homogeneous phantoms were used to obtain ESD to younger children, because the technique uses a so small kVp that the dosimeters would produce an artifact image in the patient radiograph. Four kinds of pediatric examinations were investigated: three conventional examinations (chest, skull and abdomen) and a fluoroscopic procedure (barium swallow). Relevant information about kVp and mAs values used in the examinations was collected, and we discuss how these parameters can affect the ESD. The ESD values measured in this work are compared to reference levels published by the European Commission for pediatric patients. The results obtained (third-quartile of the ESD distribution) for chest AP examinations in three age groups were: 0.056 mGy (2-4 years old); 0,068 mGy (5-9 years old)-. 0.069 mGy (10-15 years old). All of them are below the European reference level (0.100mGy). ESD values measured to the older age group in skull and abdomen AP radiographs (mean values 3.44 and 1.20mGy, respectively) are above the European reference levels (1.5mGy to skull and 1.0 mGy to abdomen). ESD values measured in the barium swallow examination reached 10 mGy in skin regions corresponding to thyroid and esophagus. It was noticed during this survey that some technicians use, improperly, X-ray fluoroscopy in conventional examinations to help them in positioning the patient. The results presented here are a preliminary survey of doses in pediatric radiological examinations and they show that it is necessary to investigate the technical parameters to perform the radiographs. to introduce practices to control pediatric patient`s doses and to improve the personnel training to perform a pediatric examination. (c) 2007 Elsevier Ltd. All rights reserved.

The transition from pediatric to adult health care services for young adults with a disability : an ethical perspective

Young children with disabilities and their carers or parents tend to form a long-term dependent relationship with a paediatrician throughout childhood At some stage when the young person with a disability reaches early adulthood, the relationship is severed This paper draws upon recent research undertaken by the authors that describes the difficulties experienced by young people with disabilities as they go through the transition from paediatric care to adult mainstream health care services. The purpose of this article is to present the argument that the dependent, paternalistic relationship that tends to exist between young people with disabilities (and/or their carers) and paediatricians throughout childhood does not facilitate the successful negotiation of adult mainstream health care services, nor optimally promote the well-being of these young people with disabilities. It is proposed that the promotion of autonomy (or self-determination) via a well planned transition program will increase the likelihood that young adults with disabilities and/or their carers will be empowered to successfully negotiate the current mainstream health care system in Australia, and will enhance the well-being of young adults with disabilities.

Preliminary validation of the Chinese version of the pediatric quality of life inventory

The Pediatric Quality of Life Inventory (PedsQL) is a scale for assessing health-related quality of life of children and adolescents aged 2-18 years. Three reports of PedsQL for the age ranges 2-4 years and 5-7 years were translated into Chinese and their validities were examined. A total of 186 children and parents were involved in the study. Content validity, test-retest reliability, internal consistency reliability and construct validity were assessed. The correlation of parents' and children's reports was also examined. The results showed that the internal consistency is generally good, test-retest reliability ranged from moderate to good, differences between disabled and non-disabled individuals are significant in total scores and in all subscales except for the physical functioning subscale for the children's self-report for the age ranges of 2-4 years and 5-7 years and the correlation between the reports of the parents and children for the age range of 5-7 years is moderate to high. This suggests that the newly translated Chinese PedsQL for children aged 2-4 years and 5-7 years seems to be reliable and valid to be used as a measure of health-related quality of life in Chinese pediatric research and clinical applications.