Search

Complete blood count (CBC) values are monitored as crude indicators of the hemolytic and inflammatory processes that accompany an acute painful episode in children with sickle cell disease. As part of a larger study that examined the pain experience and pain management of hospitalized children during painful vaso-occlusive episodes, the authors examined trends in CBC values and determined whether there were relationships between these values and pain intensity scores. Children, 5 to 19 years of age, with sickle cell disease whose primary reason for admission was vasoocclusive pain were recruited for participation in the study. Once every evening from the day of admission until the day of discharge, they were asked to rate their worst and least pain using the numeric rating scale of the African American Oucher pain scale. Complete blood count values were obtained from the hospital information system on a daily basis. Parallel changes in CBC values and pain intensity scores were evident within the first 48 hours of hospitalization. However, although the inflammatory and hemolytic processes were resolving, pain persisted at moderate levels throughout the course of hospitalization. Copyright © 2005 by Association of Pediatric Oncology Nurses [ABSTRACT FROM AUTHOR]

Cyanobacteria are the most prevalent bloom-forming harmful algae in freshwater systems around the world. Adequate sampling of affected systems is limited spatially, temporally, and fiscally. Remote sensing using space- or ground-based systems in large water bodies at spatial and temporal scales that are cost-prohibitive to standard water quality monitoring has proven to be useful in detecting and quantifying cyanobacterial harmful algal blooms. This study aimed to identify a regional 'universal' multispectral reflectance model that could be used for rapid, remote detection and quantification of cyanoHABs in small- to medium-sized productive reservoirs, such as those typical of Oklahoma, USA. We aimed to include these small waterbodies in our study as they are typically overlooked in larger, continental wide studies, yet are widely distributed and used for recreation and drinking water supply. We used Landsat satellite reflectance and in-situ pigment data spanning 16 years from 38 reservoirs in Oklahoma to construct empirical linear models for predicting concentrations of chlorophyll-a and phycocyanin, two key algal pigments commonly used for assessing total and cyanobacterial algal abundances, respectively. We also used ground-based hyperspectral reflectance and in-situ pigment data from seven reservoirs across five years in Oklahoma to build multispectral models predicting algal pigments from newly defined reflectance bands. Our Oklahoma-derived Landsat- and ground-based models outperformed established reflectance-pigment models on Oklahoma reservoirs. Importantly, our results demonstrate that ground-based multispectral models were far superior to Landsat-based models and the Cyanobacteria Index (CI) for detecting cyanoHABs in highly productive, small- to mid-sized reservoirs in Oklahoma, providing a valuable tool for water management and public health. While satellite-based remote sensing approaches have proven effective for relatively large systems, our novel results indicate that ground-based remote sensing may offer better cyanoHAB monitoring for small or highly dendritic turbid lakes, such as those throughout the southern Great Plains, and thus prove beneficial to efforts aimed at minimizing public health risks associated with cyanoHABs in supply and recreational waters., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Microcystis , a common harmful algal bloom (HAB) taxon, threatens water supplies and human health, yet species delimitation is contentious in this taxon, leading to challenges in research and management of this threat. Historical and common morphology-based classifications recognize multiple morphospecies, most with variable and diverse ecologies, while DNA sequence-based classifications indicate a single species with multiple ecotypes. To better delimit Microcystis species, we conducted a pangenome analysis of 122 genomes. Core- and non-core gene phylogenetic analyses placed 113 genomes into 23 monophyletic clusters containing at least two genomes. Overall, genome-related indices revealed that Microcystis contains at least 16 putative genospecies. Fifteen genospecies included at least one Microcystis aeruginosa morphospecies, and 10 genospecies included two or more morphospecies. This classification system will enable consistent taxonomic identification of Microcystis and thereby aid in resolving some of the complexities and controversies that have long characterized eco-evolutionary research and management of this important HAB taxon.

Growing attention in aquatic ecology is focusing on biogeographic patterns in microorganisms and whether these potential patterns can be explained within the framework of general ecology. The long-standing microbiologist's credo 'Everything is everywhere, but, the environment selects' suggests that dispersal is not limiting for microbes, but that the environment is the primary determining factor in microbial community composition. Advances in molecular techniques have provided new evidence that biogeographic patterns exist in microbes and that dispersal limitation may actually have an important role, yet more recent study using extremely deep sequencing predicts that indeed everything is everywhere. Using a long-term field study of the 'invasive' marine haptophyte Prymnesium parvum, we characterize the environmental niche of P. parvum in a subtropical impoundment in the southern United States. Our analysis contributes to a growing body of evidence that indicates a primary role for environmental conditions, but not dispersal, in the lake-wide abundances and seasonal bloom patterns in this globally important microbe.

We synthesise traditional unstructured food webs, allometric body size scaling, trait-based modelling, and physiologically structured modelling to provide a novel and ecologically relevant tool for size-structured food webs. The framework allows food web models to include ontogenetic growth and life-history omnivory at the individual level by resolving the population structure of each species as a size-spectrum. Each species is characterised by the trait 'size at maturation', and all model parameters are made species independent through scaling with individual body size and size at maturation. Parameter values are determined from cross-species analysis of fish communities as life-history omnivory is widespread in aquatic systems, but may be reparameterised for other systems. An ensemble of food webs is generated and the resulting communities are analysed at four levels of organisation: community level, species level, trait level, and individual level. The model may be solved analytically by assuming that the community spectrum follows a power law. The analytical solution provides a baseline expectation of the results of complex food web simulations, and agrees well with the predictions of the full model on biomass distribution as a function of individual size, biomass distribution as a function of size at maturation, and relation between predator-prey mass ratio of preferred and eaten food. The full model additionally predicts the diversity distribution as a function of size at maturation., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Individual and trophic efficiencies of size-structured communities are derived from mechanistically based principles at the individual level. The derivations are relevant for communities with a size-based trophic structure, i.e. where trophic level is strongly correlated with individual size as in many aquatic systems. The derivations are used to link Lindeman's trophic theory and trophic theory based on average individuals with explicit individual-level size spectrum theory. The trophic efficiency based on the transfer of mass between trophic levels through predator-prey interactions is demonstrated to be valid only when somatic growth can be ignored. Taking somatic growth into account yields an average individual growth efficiency that is smaller than the trophic efficiency.

The reproductive strategy of most fishes is to produce a large number of tiny eggs, leading to a huge difference between egg size and asymptotic body size. The viability of this strategy is examined by calculating the life-time reproductive success R(0) as a function of the asymptotic body size. A simple criterion for the optimality of producing small eggs is found, depending on the rate of predation relative to the specific rate of consumption. Secondly it is shown that the success of the reproductive strategy is increasing with asymptotic body size. Finally the existence of both upper and lower limits on the allowed asymptotic sizes is demonstrated. A metabolic upper limit to asymptotic body size for all higher animals is derived.

The majority of higher organisms in the marine environment display indeterminate growth; that is, they continue to grow throughout their life, limited by an asymptotic size. We derive the abundance of species as a function of their asymptotic size. The derivation is based on size-spectrum theory, where population structure is derived from physiology and simple arguments regarding the predator-prey interaction. Using a hypothesis of constant satiation, which states that the average degree of satiation is independent of the size of an organism, the number of individuals with a given size is found to be proportional to the weight raised to the power -2.05, independent of the predator/prey size ratio. This is the first time the spectrum exponent has been derived solely on the basis of processes at the individual level. The theory furthermore predicts that the parameters in the von Bertalanffy growth function are related as K ∝ L⁻¹∞

As part of a larger study that examined pain experience, pain management, and pain outcomes among children with sickle cell disease, functional status (sleep, food intake, and activity levels) was examined during hospitalization for acute painful episodes. Children were asked to rate the amount of pain they experienced as well as the amount of time they slept, the amount of food they ate, and the amount of activity they had everyday. Children reported high levels of pain, which showed only a small decrease throughout hospitalization, and had disrupted sleep and wake patterns, decreased food intake, and decreased activity levels. Nurses need to routinely monitor functional status during acute painful episodes so that strategies to promote adequate sleep, food intake, and activity may be incorporated to minimize long-term negative outcomes in children with sickle cell disease.

This paper derives optimal life histories for fishes or other animals in relation to the size spectrum of the ecological community in which they are both predators and prey. Assuming log-linear size-spectra and well known scaling laws for feeding and mortality, we first construct the energetics of the individual. From these we find, using dynamic programming, the optimal allocation of energy between growth and reproduction as well as the trade-off between offspring size and numbers. Optimal strategies were found to be strongly dependent on size spectrum slope. For steep size spectra (numbers declining rapidly with size), determinate growth was optimal and allocation to somatic growth increased rapidly with increasing slope. However, restricting reproduction to a fixed mating season changed optimal allocations to give indeterminate growth approximating a von Bertalanffy trajectory. The optimal offspring size was as small as possible given other restrictions such as newborn starvation mortality. For shallow size spectra, finite optimal maturity size required a decline in fitness for large size or age. All the results are compared with observed size spectra of fish communities to show their consistency and relevance.

The purpose of this study was to describe the pain experience of children with sickle cell disease who were hospitalized for vaso-occlusive painful episodes. The pain experience, and signs and symptoms prior to admission and during hospitalization, are presented in the context of whether there is evidence to support the existence of phases to a vaso-occlusive painful episode. Children were interviewed about the onset of the painful episode and were asked to describe their pain from the day of admission to the day of discharge from the hospital. They were also observed for the absence or presence of signs and symptoms associated with the painful vaso-occlusive episode. Findings from this study provide some evidence to support previous observations related to changes during the evolution of painful episodes that may be occurring in phases (e.g., evolving, inflammatory, resolving), as previously described in adults and children. These phases had different names, although the concepts were similar.

The purpose of this study was to determine the adequacy of the alternate forms reliability of three versions of the Oucher pain scale. Because the original large-sized posters were unwieldy for use by nurses with children in clinical settings, it became necessary to reduce it in size. To determine whether the resulting tools were psychometrically equivalent to the original versions of the Oucher, this study was undertaken. In a group of 3- to 12-year-old children who underwent surgical or dental procedures ( n = 137), scores were obtained after the procedure on small and large versions of the Oucher. The order of presentation of the two different Ouchers was randomized. Findings revealed that correlation coefficients between the scores provided for the small and large versions of the Oucher were strong, positive, and significant for the Caucasian, African-American, and Hispanic versions in 3- to 12-year-old children. These results provided evidence of the adequacy of the alternate forms reliability of these scales.

This ethnographic study examined family caregivers' perceptions of the effectiveness of comfort measures used at home for children with vaso-occlusive episodes (VOE) of sickle cell disease. Interviews were conducted in the hospital while children experienced VOE. Oral analgesics and most nonpharmacologic pain relief methods were rated by caregivers as only partly effective. Major themes that emerged from interview information reflected caregivers' efforts on behalf of their children in avoiding pain episodes, keeping a normal routine, "catching" the pain, getting their minds off the pain, helping the child get through the episode, and staying out of the hospital. Understanding the role of the family caregiver in home settings may assist health care professionals to provide more empathetic care to children with VOE and to their families when children are admitted to the hospital. Findings may encourage professionals to design the most effective methods of home pain management for these families.

Purpose: A descriptive, longitudinal design was used to evaluate the pain management strategies used in children with sickle cell disease who were experiencing pain during a vaso-occlusive episode., Methods: A list of the medications (name, amount, mode of delivery, and frequency) prescribed and administered for pain management for each participant was recorded on the Medication Quantification Scale Worksheet, starting from day 1 of hospitalization to the day of discharge. Children were asked once each evening to provide three separate ratings of how much the pain medication helped them during the day, evening, and night using a 0-to-10 rating scale., Results: Using patient-controlled analgesia (PCA), children self-administered only 35% of the analgesic medications that were prescribed and reported little pain relief. No significant relationships were found between changes in pain relief scores and the amount of analgesics administered., Conclusions: Clinicians need to monitor the amount of analgesics delivered in relationship to pain relief and assist children to titrate PCA administration of analgesics to achieve optimal pain control, or to advocate for changes in the PCA regimen when children cannot assume control of pain management.

A descriptive, longitudinal design was used to examine changes in current, worst, and least pain intensity during hospitalization for a vaso-occlusive episode in children with sickle cell disease. Other dimensions of the pain experience including location and quality were also evaluated. Children reported severe pain on the day of admission with 50% of the episodes showing a current pain intensity score of >70 and a worst pain intensity score of >80. Although both pain intensity scores demonstrated statistically significant decreases by approximately 5% over the course of the hospitalization, these decreases were not clinically significant based on the recommendations made in the American Pain Society's Guideline for the management of acute and chronic pain in sickle cell disease. In contrast to the pain intensity ratings, which did not decrease in 25% of the episodes, pain location surface area decreased in 100% of the episodes. Children described the quality of vaso-occlusive pain using all categories of word descriptors from the adolescent pediatric pain tool. These findings suggest that pain associated with a vaso-occlusive episode is inadequately assessed and managed during hospitalization.

The effectiveness of analgesia during sickle cell crisis was examined in this descriptive, exploratory study. Pain scores (using the African-American Oucher and the Adolescent Pediatric Pain Tool) and analgesics administered were examined during a 2-hour observation/interview in the hospital while children/adolescents with sickle cell disease (SCD) experienced a vaso-occlusive episode (VOE). A convenience sample of twenty-one 6- to 16-year olds with SCD was included. Evidence indicated that 15 of the 21 children in the sample were in moderate to severe pain during their interviews, indicating that the analgesics did not effectively control their pain. Most participants (17) had received nalbuphine as the primary analgesic by intravenous infusion drip and/or patient-controlled analgesia pump. Many reasons were identified for the inadequate analgesia. The results suggested that the pain of SCD is very complex, requiring continuous adjustment of comfort measures, especially analgesics. More research is needed to examine pain control in children with SCD.

Objective: To examine the patterns of children's and caregivers' descriptions of pain and the comfort measures used to relieve the pain of sickle cell disease (SCD) at home and in the hospital., Design: Qualitative and quantitative techniques were used to obtain data. Participants were seen twice, first with and then without a vaso-occlusive episode. Multiple simultaneous methodological triangulation was used to integrate the findings from ethnographic interviews and observations as well as limited quantitative findings about pain and comfort measures used., Setting: A Midwestern children's hospital with a regional SCD service., Participants: Twenty-one African American children and adolescents with SCD, aged 6 to 15 years, and 21 family caregivers., Results: An 8-phase chronology of pain and comfort was revealed from the data about pain and comfort in children with SCD. Although this chronology was an unexpected finding, it was consistent with the original aim of the investigation. Phase 1 (baseline) represented the usual state of the child's condition, which for most was free of pain. Phase 2 or the "pre-pain" state involved no vasoocclusive pain but the child began to show prodromal signs and symptoms of painful episodes, such as yellowing of the eyes or fatigue. Phases 2 through 7 involved increasing then decreasing levels of pain, including the pain start point (phase 3), pain acceleration (phase 4), peak pain experience (phase 5), pain decrease start point (phase 6), and steady pain decline (phase 7). A trip to the emergency department usually occurred during phase 5. In phase 8 (pain resolution), the pain had decreased to a manageable level so that the child could be discharged from the hospital. As pain increased and decreased, so did the number and variety of comfort measures., Conclusions: A chronology of the pain and comfort experiences for children and adolescents during a vasoocclusive event of SCD emerged from the descriptive data of this study. Findings need to be examined further in larger, quantitative, longitudinal studies that examine more closely the duration, intensity, and character of pain at different times during vaso-occlusive episodes as well as the comfort measures used during specific phases of the pain event.

Issues and Purpose: Pain is the most frequent and important problem for children with sickle cell disease (SCD), but it has been undertreated and understudied. A multidisciplinary group of healthcare providers, academics, and people with SCD and their families met to (1) examine the pain of vaso-occlusive events (VOE) in children and adults with SCD and (2) reach consensus about necessary improvements in care., Conclusions: Accurate assessment of pain is at the crux of effective care for children with VOE. This requires a trusting interactive relationship among patient, family, and healthcare team. Comprehensive pain assessment is a lifelong process in need of continued updating., Practice Implications: Children with SCD seek treatment from nurses in many settings. Traditional care has been frustrating to both families and care providers. Children and adolescents with SCD pain would benefit from nursing care that considers patients' perspectives about pain and comfort as key determinants for treatment. A unified approach to pain assessment may be a significant factor in improving pain control.

This study examined the construct validity of the African-American and Hispanic versions of the Oucher Scale as measures of pain in 104 children ages 3 to 12 years old. Scores on the Oucher Scale, Analogue Chromatic Continuous Scale, and Child Medical Fear Scale were obtained after being administered concurrently on one occasion, either before or after surgery. Additionally, Oucher scores were obtained before and after analgesic administration. Significant correlations were found between the two pain intensity measures, while weak, nonsignificant relationships were revealed between the pain and fear measures. Preanalgesic scores were significantly higher than postanalgesic scores. These findings support the construct validity of the two new ethnic versions of the Oucher.

This is the first article written by this group of authors/researchers who are collaborating on the development of the Oucher, an assessment tool to assist 3- to 12-year-olds describe the intensity of pain. The background and conceptual framework for its development, the research supporting the validation of the original Oucher, the research to create new ethnic versions, and the basic instructions for clinical use are described. In addition, several issues regarding the continued development and use of the Oucher are identified, including those relative to poster size and the gender and ethnicity of the photographed child. This article illustrates the precision and care needed to create clinically useful tools for obtaining information directly from young children.

A randomized, double-blind, prospective study was performed to determine the effects of perioperative administration of morphine or methadone on postoperative analgesic requirements and pain scores in 35 children aged 3 to 7 years undergoing major surgery. After a standardized induction of anesthesia, methadone or morphine, 0.2 mg/kg, was blindly administered, and supplemental doses were titrated to achieve comfort in the recovery room. Pain was assessed during the next 36 hours with a combination of validated behavioral and self-report measures. Patients in the methadone group required fewer supplemental opioid analgesic drugs during the next 36 hours, and reported lower pain scores. No patient had prolonged emergence from anesthesia, and no patient required naloxone or postoperative ventilatory assistance. No major adverse events occurred. We conclude that perioperative intravenous administration of methadone is an effective, inexpensive, and technologically simple means for providing prolonged analgesia for children after surgery.

This study examined concurrent self-reports of pain intensity and behavioral responses in 25 children aged 3-7 yr. Behavioral (Children's Hospital of Eastern Ontario Pain Scale, CHEOPS) and self-report (the Oucher and Analogue Chromatic Continuous Scale) measures of pain were obtained following major surgery. The two self-report measures were strongly and significantly correlated, and the pattern of scores over the 36-hr observation period was as expected. There was little relationship between the scores for the self-report and the behavioral measures. Many children who reported severe pain manifested few of the behavioral indicators of distress used in the CHEOPS. This behavioral response pattern may occur commonly in children experiencing pain after surgery and may limit the applicability of current behavioral scales as sole measures of pain intensity in younger children.

Increased interest in the topic of pain has resulted in pharmacologic advances that provide new possibilities for pain relief in children. It has also resulted in new nonpharmacologic therapies that are now being used more frequently with children. It is hoped that these advances will continue so that health care providers will have a larger repertoire of pain control methods effective with children, and so that the traumatic aspects of hospitalization and health care can be reduced greatly. The pain experienced by children has heretofore been on the backroads of scientific and scholarly development. As a result, we actually know very little about pediatric pain, its measurement, and its treatment. The literature and research cited previously are strikingly limited for providing a base of knowledge to guide clinical practice. We avoided a "cookbook" approach to the discussion on pain control, because there are many of those available. Instead, we presented a summary of the research that is currently available in the attempt to help nurses better recognize the limitations in what we know with certainty about this important topic. We hope that this knowledge will spur readers to examine their own beliefs and knowledge, question former assumptions about pediatric pain, and promote a more inquiring approach to assessment and management of children's pain. Pain is a multidisciplinary problem. Although health care providers from the various disciplines each approach the pain problem from different angles, each approach has its place in the overall picture of solving the problems of pediatric pain control. Nurses have been and will continue to be a vital part of clinical and scientific advancements to move pediatric pain out of the realm of mystery and into the realm of the known.

Groups of 10 male New Zealand white rabbits were exposed by inhalation to 0, 0.1, 1.0 or 10 ppm of 1,2-dibromo-3-chloropropane (DBCP) vapor for 6 hours/day, 5 days/week for 14 weeks, except that the 10 ppm group was exposed for only 8 weeks due to mortality. The semen of rabbits was evaluated on a weekly basis during the exposure period and at periodic intervals during a recovery period (32 weeks for all groups except the 10 ppm groups which was for 38 weeks). In order to assess the fertility of the exposed rabbits, each male was allowed to mate with an unexposed female at the 14th and 41st week of the study. Exposure of rabbits to 1 and 10 ppm of DBCP by inhalation produced adverse reproductive effects as well as decreases in sperm count, motility and viability. Rabbits treated at 1 and 10 ppm had decreased sperm counts between the 8th and 14th weeks of the study. All of the 10 ppm rabbits were infertile when mated during the 14th week. The effects of DBCP on spermatogenesis were shown to be essentially reversible in rabbits exposed to 1 ppm; however, at 10 ppm, recovery was not complete under the conditions of the test. Rabbits exposed to 10 ppm had severe testicular alterations as early as 4 weeks into the study and these progressed to severe testicular atrophy by 8 weeks. Those exposed to 1 ppm for 14 weeks developed moderate testicular atrophy (approximately 50% reduction in size). Following the recovery period, the rabbits in the 10 ppm group had evidence of partial reversibility of the testicular atrophy. Electron microscopic evaluation of testicular tissue confirmed findings by light microscopy effects and also indicated increased numbers of abnormal sperm within the seminiferous tubules of rabbits at both the 10 and 1 ppm exposure levels. Those exposed to 0.1 ppm had an equivocal increase in abnormal sperm after the 14-week exposure period but not after the recovery period. Based on these results 0.1 ppm level of DBCP is considered as a no effect level for reproductive parameters.

A long-term study was conducted to determine the possible chronic toxicity and oncogenicity of methylene chloride. Rats and hamsters were exposed by inhalation to 0, 500, 1500, or 3500 ppm of methylene chloride for 6 hr per day, 5 days a week, for 2 years. No exposure-related cytogenetic effects were present in male or female rats exposed to 500, 1500, or 3500 ppm. Females rats exposed to 3500 ppm had an increased mortality rate while female hamsters exposed to 1500 or 3500 ppm had decreased mortality rates. Carboxyhemoglobin values were elevated in rats and hamsters exposed to 500, 1500, or 3500 ppm with the percentage increase in hamsters greater than in rats. Minimal histopathologic effects were present in the livers of rats exposed to 500, 1500, or 3500 ppm. Decreased amyloidosis was observed in the liver and other organs in hamsters exposed to 500, 1500 or 3500 ppm. While the number of female rats with a benign tumor was not increased, the total number of benign mammary tumors was increased in female rats in an exposure-related manner. This effect was also evident in male rats in the 1500- and 3500-ppm exposure groups. Finally, male rats exposed to 1500 or 3500 ppm had an increased number of sarcomas in the ventral neck region located in or around the salivary glands. Therefore, in this 2-year study, some effects were observed in male and female rats exposed to 500, 1500, or 3500 ppm of methylene chloride. In contrast, hamsters exposed to the same exposure concentrations had less extensive spontaneous geriatric changes, decreased mortality (females), and lacked evidence of definite target organ toxicity.

This article focuses on the methods of pain measurement and assessment in children. The concepts of reliability and validity and the available types of physiologic, self-report, and behavioral measures are addressed. Methods of pain assessment in infants and toddlers, preschoolers, school-aged children, and adolescents are detailed. Finally, some practical suggestions for pediatric pain assessment are provided.

The chronic toxicity and oncogenic potential of ingested vinylidene chloride (VDC) was evaluated in a 2-year study on Sprague-Dawley rats and the subchronic toxicity was evaluated in beagle dogs in a 97-day study. The vinylidene chloride was incorporated in the drinking water of the rats at nominal concentrations of 50, 100 or 200 ppm. The time weighted average mg/kg body weight/day dosages of vinylidene chloride administered to the male and female rats over the 2-year period at the various mean analyzed concentrations were 7, 10 or 20 for the males and 9, 14 or 30 for the females. Dogs were administered vinylidene chloride in peanut oil incorporated in a gelatin capsule at concentrations which provided 6.25, 12.5 or 25 mg vinylidene chloride/kg body weight/day. There were no significant differences between the groups of rats or dogs ingesting vinylidene chloride and their corresponding control groups in the following parameters: appearance and demeanor, mortality, body weight, food consumption, hematology, urinalysis, clinical chemistry determinations, organ weights and organ to body weight ratios. There were no significant differences in water consumption of the groups of rats ingesting vinylidene chloride and the controls. The sole treatment-related observation in the rats, evident only upon microscopic examination, was in the liver. The observation was characterized by a minimal amount of hepatocellular swelling with midzonal fatty change which occurred in the females at all dose levels and in the males only at the 200 ppm level. No exposure-related neoplastic changes occurred in the rats in any of the test groups. No exposure-related gross or histopathological changes were present in the tissues taken from the dogs at the termination of the 97-day study.

Groups of male and female Fischer 344 rats were administered acrylamide in their drinking water at 0, 0.05, 0.2, 1, 5, or 20 mg/kg/day for up to 93 days. Following the administration of acrylamide in the drinking water, male rats from each dose level were held for up to 144 days of recovery. The 20 mg/kg/day groups had definite treatment-related effects after 92 (males) and 93 (females) days. They were dragging the rear limbs, body weights were decreased, serum cholinesterase activity was decreased in top dose females, and packed cell volume, red blood cell, and hemoglobin values were slightly decreased in males and females. In the 20 mg/kg/day groups, the primary target tissue was the peripheral nerve with lesions consisting of severe degeneration characterized by demyelinization and axonal loss. Slight spinal cord degeneration was observed. Other effects included atrophy of skeletal muscle, testicular atrophy, and distended urinary bladders; these were probably secondary to the nerve degeneration. After 144 days of recovery, the lesions had partially or completely reversed. Parameters affected at the 5 mg/kg/day dose level after 92 (males) and 93 (females) days consisted of peripheral nerve degeneration which were of a lesser degree of severity than those seen in the 20 mg/kg/day groups and appeared to have completely reversed after 111 days of recovery. In rats given 1 mg/kg/day, a minimal treatment-related effect was observed in males after 92 days, and this was limited to very slight nerve degeneration using electron microscopy (females were not examined by electron microscopy). This observed effect appeared to have reversed after 25 days of recovery. No treatment-related effects were seen in any of the parameters monitored in the rats given 0.05 or 0.2 mg/kg/day of acrylamide.

This paper focuses on some of the major issues surrounding the measurement of children's pain, particularly as they relate to problems of definition, level of measurement, dimensionality, reliability, and validity. The authors briefly describe some of the tools used with children and point out some of the problems that have resulted from the lack of well-tested, thoroughly validated instruments for children. As a common experience of hospitalized children, pediatric pain is creating concern within the health care community. The authors recommend that more attention be paid to the measurement issues surrounding this clinical phenomenon.

The postoperative prescription and administration of analgesics following cardiac surgery for 50 children were compared with those of 50 adults. Six children were the only patients in the sample who were prescribed no postoperative analgesics. Overall, children were prescribed significantly fewer potent narcotics. The administration data revealed even more pronounced group differences. During the observation period, children received 30% of all analgesic administrations while adults received 70%. Some possible reasons for these age differences in analgesic usage are presented, and implications regarding the adequacy of postoperative pain control in children are discussed.

This paper focuses on the knowledge base about the assessment and management of postoperative pain in children. The first section deals with the nature and characteristics of postoperative pain. A description of current pain management practices with children, focusing on analgesic administration, is derived from available research literature. These reports suggest that postoperative pediatric pain relief may be inadequate. Recent advances in pain assessment and measurement in all age groups, particularly with verbal children and the new self-report measures, are discussed. The latest developments in pharmacological and nonpharmacological techniques for the relief of children's postoperative pain are also described. Finally, the paper concludes with a few suggestions for pediatricians relative to their role in assisting in the search for better assessment and management techniques in the care of postoperative children.