Anticoagulation practices associated with bleeding and thrombosis in pediatric extracorporeal membrane oxygenation; a multi-center secondary analysis

To determine associations between anticoagulation practices and bleeding and thrombosis during pediatric extracorporeal membrane oxygenation (ECMO), we performed a secondary analysis of prospectively collected data which included 481 children (<19 years), between January 2012 and September 2014. The primary outcome was bleeding or thrombotic events. Bleeding events included a blood product transfusion >80 ml/kg on any day, pulmonary hemorrhage, or intracranial bleeding, Thrombotic events included pulmonary emboli, intracranial clot, limb ischemia, cardiac clot, and arterial cannula or entire circuit change. Bleeding occurred in 42% of patients. Five percent of subjects thrombosed, of which 89% also bled. Daily bleeding odds were independently associated with day prior activated clotting time (ACT) (OR 1.03, 95% CI= 1.00, 1.05, p=0.047) and fibrinogen levels (OR 0.90, 95% CI 0.84, 0.96, p <0.001). Thrombosis odds decreased with increased day prior heparin dose (OR 0.88, 95% CI 0.81, 0.97, p=0.006). Lower ACT values and increased fibrinogen levels may be considered to decrease the odds of bleeding. Use of this single measure, however, may not be sufficient alone to guide optimal anticoagulation practice during ECMO.

Peroxisomes as cellular adaptors to metabolic and environmental stress

Peroxisomes are involved in multiple metabolic processes, including fatty acid oxidation, ether lipid synthesis, and reactive oxygen species (ROS) metabolism. Recent studies suggest that peroxisomes are critical mediators of cellular responses to various forms of stress, including oxidative stress, hypoxia, starvation, cold exposure, and noise. As dynamic organelles, peroxisomes can modulate their proliferation, morphology, and movement within cells, and engage in crosstalk with other organelles in response to external cues. Although peroxisome-derived hydrogen peroxide has a key role in cellular signaling related to stress, emerging studies suggest that other products of peroxisomal metabolism, such as acetyl-CoA and ether lipids, are also important for metabolic adaptation to stress. Here, we review molecular mechanisms through which peroxisomes regulate metabolic and environmental stress.

MED19 Regulates Adipogenesis and Maintenance of White Adipose Tissue Mass by Mediating PPARγ-Dependent Gene Expression

The Mediator complex relays regulatory signals from gene-specific transcription factors to the basal transcriptional machinery. However, the role of individual Mediator subunits in different tissues remains unclear. Here, we demonstrate that MED19 is essential for adipogenesis and maintenance of white adipose tissue (WAT) by mediating peroxisome proliferator-activated receptor gamma (PPARγ) transcriptional activity. MED19 knockdown blocks white adipogenesis, but not brown adipogenesis or C2C12 myoblast differentiation. Adipose-specific MED19 knockout (KO) in mice results in a striking loss of WAT, whitening of brown fat, hepatic steatosis, and insulin resistance. Inducible adipose-specific MED19 KO in adult animals also results in lipodystrophy, demonstrating its requirement for WAT maintenance. Global gene expression analysis reveals induction of genes involved in apoptosis and inflammation and impaired expression of adipose-specific genes, resulting from decreased PPARγ residency on adipocyte gene promoters and reduced association of PPARγ with RNA polymerase II. These results identify MED19 as a crucial facilitator of PPARγ-mediated gene expression in adipose tissue.

Hepatic peroxisomal β-oxidation suppresses lipophagy via RPTOR acetylation and MTOR activation

Hepatic lipid homeostasis is controlled by a coordinated regulation of various metabolic pathways involved in de novo synthesis, uptake, storage, and catabolism of lipids. Disruption of this balance could lead to hepatic steatosis. Peroxisomes play an essential role in lipid metabolism, yet their importance is often overlooked. In a recent study, we demonstrated a role for hepatic peroxisomal β-oxidation in autophagic degradation of lipid droplets. ACOX1 (acyl-Coenzyme A oxidase 1, palmitoyl), the rate-limiting enzyme of peroxisomal β-oxidation, increases with fasting or high-fat diet (HFD). Liver-specific acox1 knockout (acox1-LKO) protects mice from hepatic steatosis induced by starvation or HFD via induction of lipophagy. Mechanistically, we showed that hepatic ACOX1 deficiency decreases the total cytosolic acetyl-CoA levels, which leads to reduced acetylation of RPTOR/RAPTOR, a component of MTORC1, which is a key regulator of macroautophagy/autophagy. These results identify peroxisome-derived acetyl-CoA as a critical metabolic regulator of autophagy that controls hepatic lipid homeostasis.

Peroxisome-derived lipids regulate adipose thermogenesis by mediating cold-induced mitochondrial fission

Peroxisomes perform essential functions in lipid metabolism, including fatty acid oxidation and plasmalogen synthesis. Here, we describe a role for peroxisomal lipid metabolism in mitochondrial dynamics in brown and beige adipocytes. Adipose tissue peroxisomal biogenesis was induced in response to cold exposure through activation of the thermogenic coregulator PRDM16. Adipose-specific knockout of the peroxisomal biogenesis factor Pex16 (Pex16-AKO) in mice impaired cold tolerance, decreased energy expenditure, and increased diet-induced obesity. Pex16 deficiency blocked cold-induced mitochondrial fission, decreased mitochondrial copy number, and caused mitochondrial dysfunction. Adipose-specific knockout of the peroxisomal β-oxidation enzyme acyl-CoA oxidase 1 (Acox1-AKO) was not sufficient to affect adiposity, thermogenesis, or mitochondrial copy number, but knockdown of the plasmalogen synthetic enzyme glyceronephosphate O-acyltransferase (GNPAT) recapitulated the effects of Pex16 inactivation on mitochondrial morphology and function. Plasmalogens are present in mitochondria and decreased with Pex16 inactivation. Dietary supplementation with plasmalogens increased mitochondrial copy number, improved mitochondrial function, and rescued thermogenesis in Pex16-AKO mice. These findings support a surprising interaction between peroxisomes and mitochondria regulating mitochondrial dynamics and thermogenesis.

PexRAP Inhibits PRDM16-Mediated Thermogenic Gene Expression

How the nuclear receptor PPARγ regulates the development of two functionally distinct types of adipose tissue, brown and white fat, as well as the browning of white fat, remains unclear. Our previous studies suggest that PexRAP, a peroxisomal lipid synthetic enzyme, regulates PPARγ signaling and white adipogenesis. Here, we show that PexRAP is an inhibitor of brown adipocyte gene expression. PexRAP inactivation promoted adipocyte browning, increased energy expenditure, and decreased adiposity. Identification of PexRAP-interacting proteins suggests that PexRAP function extends beyond its role as a lipid synthetic enzyme. Notably, PexRAP interacts with importin-β1, a nuclear import factor, and knockdown of PexRAP in adipocytes reduced the levels of nuclear phospholipids. PexRAP also interacts with PPARγ, as well as PRDM16, a critical transcriptional regulator of thermogenesis, and disrupts the PRDM16-PPARγ complex, providing a potential mechanism for PexRAP-mediated inhibition of adipocyte browning. These results identify PexRAP as an important regulator of adipose tissue remodeling.

Structural and functional roles of ether lipids

Ether lipids, such as plasmalogens, are peroxisome-derived glycerophospholipids in which the hydrocarbon chain at the sn-1 position of the glycerol backbone is attached by an ether bond, as opposed to an ester bond in the more common diacyl phospholipids. This seemingly simple biochemical change has profound structural and functional implications. Notably, the tendency of ether lipids to form non-lamellar inverted hexagonal structures in model membranes suggests that they have a role in facilitating membrane fusion processes. Ether lipids are also important for the organization and stability of lipid raft microdomains, cholesterol-rich membrane regions involved in cellular signaling. In addition to their structural roles, a subset of ether lipids are thought to function as endogenous antioxidants, and emerging studies suggest that they are involved in cell differentiation and signaling pathways. Here, we review the biology of ether lipids and their potential significance in human disorders, including neurological diseases, cancer, and metabolic disorders.

Technology in Parkinson's disease: Challenges and opportunities

The miniaturization, sophistication, proliferation, and accessibility of technologies are enabling the capture of more and previously inaccessible phenomena in Parkinson's disease (PD). However, more information has not translated into a greater understanding of disease complexity to satisfy diagnostic and therapeutic needs. Challenges include noncompatible technology platforms, the need for wide-scale and long-term deployment of sensor technology (among vulnerable elderly patients in particular), and the gap between the "big data" acquired with sensitive measurement technologies and their limited clinical application. Major opportunities could be realized if new technologies are developed as part of open-source and/or open-hardware platforms that enable multichannel data capture sensitive to the broad range of motor and nonmotor problems that characterize PD and are adaptable into self-adjusting, individualized treatment delivery systems. The International Parkinson and Movement Disorders Society Task Force on Technology is entrusted to convene engineers, clinicians, researchers, and patients to promote the development of integrated measurement and closed-loop therapeutic systems with high patient adherence that also serve to (1) encourage the adoption of clinico-pathophysiologic phenotyping and early detection of critical disease milestones, (2) enhance the tailoring of symptomatic therapy, (3) improve subgroup targeting of patients for future testing of disease-modifying treatments, and (4) identify objective biomarkers to improve the longitudinal tracking of impairments in clinical care and research. This article summarizes the work carried out by the task force toward identifying challenges and opportunities in the development of technologies with potential for improving the clinical management and the quality of life of individuals with PD. © 2016 International Parkinson and Movement Disorder Society.

Fish functional traits are affected by hydrodynamics at small spatial scale

The Mediterranean damselfish Chromis chromis is a species with a broad distribution found both in the Mediterranean Sea and Eastern Atlantic as far south as the coast of Angola. We hypothesized that the species may have significant functional morphological plasticity to adapt along a gradient of environmental conditions. It is a non-migratory zooplanktivorous species and spends the daytime searching for food in the middle of the water column. Therefore, local hydrodynamics could be one of the environmental factors affecting traits of C. chromis with repercussions at the population level. We compared the body condition, individual growth and body shapes of damselfish collected under two different hydrodynamic conditions (low ∼10 cm s(-1) vs. high ∼20 cm s(-1)). Specimens showed higher body condition under high-hydrodynamics, where conditions offered greater amounts of food, which were able to support larger individuals. Individuals smaller than 60-mm were more abundant under low-hydrodynamics. Morphometric analysis revealed that high-hydrodynamics were favored by fish with a more fusiform body shape and body traits developed for propellant swimming.

Linked Records of Children with Traumatic Brain Injury. Probabilistic Linkage without Use of Protected Health Information

OBJECTIVE

Record linkage may create powerful datasets with which investigators can conduct comparative effectiveness studies evaluating the impact of tests or interventions on health. All linkages of health care data files to date have used protected health information (PHI) in their linkage variables. A technique to link datasets without using PHI would be advantageous both to preserve privacy and to increase the number of potential linkages.

METHODS

We applied probabilistic linkage to records of injured children in the National Trauma Data Bank (NTDB, N = 156,357) and the Pediatric Health Information Systems (PHIS, N = 104,049) databases from 2007 to 2010. 49 match variables without PHI were used, many of them administrative variables and indicators for procedures recorded as International Classification of Diseases, 9th revision, Clinical Modification codes. We validated the accuracy of the linkage using identified data from a single center that submits to both databases.

RESULTS

We accurately linked the PHIS and NTDB records for 69% of children with any injury, and 88% of those with severe traumatic brain injury eligible for a study of intervention effectiveness (positive predictive value of 98%, specificity of 99.99%). Accurate linkage was associated with longer lengths of stay, more severe injuries, and multiple injuries.

CONCLUSION

In populations with substantial illness or injury severity, accurate record linkage may be possible in the absence of PHI. This methodology may enable linkages and, in turn, comparative effectiveness studies that would be unlikely or impossible otherwise.

The utility of imputed matched sets. Analyzing probabilistically linked databases in a low information setting

OBJECTIVE

To compare results from high probability matched sets versus imputed matched sets across differing levels of linkage information.

METHODS

A series of linkages with varying amounts of available information were performed on two simulated datasets derived from multiyear motor vehicle crash (MVC) and hospital databases, where true matches were known. Distributions of high probability and imputed matched sets were compared against the true match population for occupant age, MVC county, and MVC hour. Regression models were fit to simulated log hospital charges and hospitalization status.

RESULTS

High probability and imputed matched sets were not significantly different from occupant age, MVC county, and MVC hour in high information settings (p > 0.999). In low information settings, high probability matched sets were significantly different from occupant age and MVC county (p < 0.002), but imputed matched sets were not (p > 0.493). High information settings saw no significant differences in inference of simulated log hospital charges and hospitalization status between the two methods. High probability and imputed matched sets were significantly different from the outcomes in low information settings; however, imputed matched sets were more robust.

CONCLUSIONS

The level of information available to a linkage is an important consideration. High probability matched sets are suitable for high to moderate information settings and for situations involving case-specific analysis. Conversely, imputed matched sets are preferable for low information settings when conducting population-based analyses.

mPEG-PAMAM-G4 nucleic acid nanocomplexes: enhanced stability, RNase protection, and activity of splice switching oligomer and poly I:C RNA

Dendrimer chemistries have virtually exploded in recent years with increasing interest in this class of polymers as gene delivery vehicles. An effective nucleic acid delivery vehicle must efficiently bind its cargo and form physically stable complexes. Most importantly, the nucleic acid must be protected in biological fluids and tissues, as RNA is extremely susceptible to nuclease degradation. Here, we characterized the association of nucleic acids with generation 4 PEGylated poly(amidoamine) dendrimer (mPEG-PAMAM-G4). We investigated the formation, size, and stability over time of the nanoplexes at various N/P ratios by gel shift and dynamic light scatter spectroscopy (DLS). Further characterization of the mPEG-PAMAM-G4/nucleic acid association was provided by atomic force microscopy (AFM) and by circular dichroism (CD). Importantly, mPEG-PAMAM-G4 complexation protected RNA from treatment with RNase A, degradation in serum, and various tissue homogenates. mPEG-PAMAM-G4 complexation also significantly enhanced the functional delivery of RNA in a novel engineered human melanoma cell line with splice-switching oligonucleotides (SSOs) targeting a recombinant luciferase transcript. mPEG-PAMAM-G4 triconjugates formed between gold nanoparticle (GNP) and particularly manganese oxide (MnO) nanorods, poly IC, an anticancer RNA, showed enhanced cancer-killing activity by an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay.

Induced cerebral hypothermia reduces post-hypoxic loss of phenotypic striatal neurons in preterm fetal sheep

Perinatal hypoxic-ischemic injury of the basal ganglia is a significant cause of disability in premature infants. Prolonged, moderate cerebral hypothermia has been shown to be neuroprotective after experimental hypoxia-ischemia; however, it has not been tested in the preterm brain. We therefore examined the effects of severe hypoxia and the potential neuroprotective effects of delayed hypothermia on phenotypic striatal neurons. Preterm (0.7 gestation) fetal sheep received complete umbilical cord occlusion for 25 min followed by cerebral hypothermia (fetal extradural temperature reduced from 39.4+/-0.3 degrees C to 29.5+/-2.6 degrees C) from 90 min to 70 h after the end of occlusion. Hypothermia was associated with a significant overall reduction in striatal neuronal loss compared with normothermia-occlusion fetuses (mean+/-SEM, 5.5+/-1.2% vs. 38.1+/-6.5%, P<0.01). Immunohistochemical studies showed that occlusion resulted in a significant loss of calbindin-28 kd, glutamic acid decarboxylase isoform 67 and neuronal nitric oxide synthase-immunopositive neurons (n=7, P<0.05), but not choline acetyltransferase-positive neurons, compared with sham controls (n=7). Hypothermia (n=7) significantly reduced the loss of calbindin-28 kd and neuronal nitric oxide synthase, but not glutamic acid decarboxylase-immunopositive neurons. In conclusion, delayed, prolonged moderate head cooling was associated with selective protection of particular phenotypic striatal projection neurons after severe hypoxia in the preterm fetus. These findings suggest that head cooling may help reduce basal ganglia injury in some premature babies.

The effect of cerebral hypothermia on white and grey matter injury induced by severe hypoxia in preterm fetal sheep

Prolonged, moderate cerebral hypothermia is consistently neuroprotective after experimental hypoxia-ischaemia; however, it has not been tested in the preterm brain. Preterm (0.7 gestation) fetal sheep received complete umbilical cord occlusion for 25 min followed by cerebral hypothermia (fetal extradural temperature reduced from 39.4 +/- 0.3 to 29.5 +/- 2.6 degrees C) from 90 min to 70 h after the end of occlusion or sham cooling. Occlusion led to severe acidosis and profound hypotension, which recovered rapidly after release of occlusion. After 3 days recovery the EEG spectral frequency, but not total intensity, was increased in the hypothermia-occlusion group compared with normothermia-occlusion. Hypothermia was associated with a significant overall reduction in loss of immature oligodendrocytes in the periventricular white matter (P < 0.001), and neuronal loss in the hippocampus and basal ganglia (P < 0.001), with suppression of activated caspase-3 and microglia (isolectin-B4 positive). Proliferation was significantly reduced in periventricular white matter after occlusion (P < 0.05), but not improved after hypothermia. In conclusion, delayed, prolonged head cooling after a profound hypoxic insult in the preterm fetus was associated with a significant reduction in loss of neurons and immature oligodendroglia, with evidence of EEG and haemodynamic improvement after 3 days recovery, but also with a persisting reduction in proliferation of cells in the periventricular region. Further studies are required to evaluate the long-term impact of cooling on brain growth and maturation.

Differential effects of hypothermia on early and late epileptiform events after severe hypoxia in preterm fetal sheep

Moderate cerebral hypothermia is consistently neuroprotective after experimental hypoxia-ischemia; however, its mechanisms remain poorly defined. Using a model of complete umbilical cord occlusion for 25 min in 0.7 gestation fetal sheep, we examined the effects of cerebral hypothermia (fetal extradural temperature reduced from 39.5 +/- 0.2 degrees C to <34 degrees C; mean +/- SD), from 90 min to 70 h after the end of the insult, on postocclusion epileptiform activity. In the first 6 h after the end of occlusion, fetal electroencephalographic (EEG) activity was abnormal with a mixture of fast and slow epileptiform transients superimposed on a suppressed background; seizures started a mean of 8 h after occlusion. There was a close correlation between numbers of these EEG transients and subsequent neuronal loss in the striatum after 3 days recovery (r(2) = 0.65, P = 0.008). Hypothermia was associated with a marked reduction in numbers of epileptiform transients in the first 6 h, reduced amplitude of seizures, and reduced striatal neuronal loss. In conclusion, neuroprotection with delayed, prolonged head cooling after a severe asphyxial insult in the preterm fetus was associated with potent, specific suppression of epileptiform transients in the early recovery phase but not of numbers of delayed seizures.

Endogenous alpha2-adrenergic receptor-mediated neuroprotection after severe hypoxia in preterm fetal sheep

Central alpha-adrenergic receptor activity is important for fetal adaptation to hypoxia before birth. It is unclear whether it is also important during recovery. We therefore tested the hypothesis that an infusion of the specific alpha(2)-adrenergic receptor antagonist idazoxan (1 mg/kg/h i.v.) from 15 min to 4 h after profound hypoxia induced by 25 min umbilical cord occlusion in fetal sheep at 70% of gestation (equivalent to the 28-32 weeks in humans) would increase neural injury. After 3 days' recovery, idazoxan infusion was associated with a significant increase in neuronal loss in the hippocampus (P<0.05), expression of cleaved caspase-3 (P<0.05), and numbers of activated microglia (P<0.05). There was no significant effect on other neuronal regions or on loss of O4-positive premyelinating oligodendrocytes in the subcortical white matter. Idazoxan was associated with an increase in evolving epileptiform electroencephalographic (EEG) transient activity after occlusion (difference at peak 2.5+/-1.0 vs. 11.7+/-4.7 counts/min, P<0.05) and significantly reduced average spectral edge frequency, but not EEG intensity, from 54 until 72 h after occlusion (P<0.05). Hippocampal neuronal loss was correlated with total numbers of epileptiform transients during idazoxan infusion (P<0.01; r(2)=0.7). In conclusion, endogenous inhibitory alpha(2)-adrenergic receptor activation after severe hypoxia appears to significantly limit evolving hippocampal damage in the immature brain.

Analyses of nuclear ldhA gene and mtDNA control region sequences of Atlantic northern bluefin tuna populations

There has been considerable debate about whether the Atlantic northern bluefin tuna exist as a single panmictic unit. We have addressed this issue by examining both mitochondrial DNA control region nucleotide sequences and nuclear gene ldhA allele frequencies in replicate size or year class samples of northern bluefin tuna from the Mediterranean Sea and the northwestern Atlantic Ocean. Pairwise comparisons of multiple year class samples from the 2 regions provided no evidence for population subdivision. Similarly, analyses of molecular variance of both mitochondrial and ldhA data revealed no significant differences among or between samples from the 2 regions. These results demonstrate the importance of analyzing multiple year classes and large sample sizes to obtain accurate estimates when using allele frequencies to characterize a population. It is important to note that the absence of genetic evidence for population substructure does not unilaterally constitute evidence of a single panmictic population, as genetic differentiation can be prevented by large population sizes and by migration.

Development and impact of a computerized pediatric antiinfective decision support program

OBJECTIVE

Computerized medical decision support tools have been shown to improve the quality of care and have been cited by the Institute of Medicine as one method to reduce pharmaceutical errors. We evaluated the impact of an antiinfective decision support tool in a pediatric intensive care unit (PICU).

METHODS

We enhanced an existing adult antiinfective management tool by adding and changing medical logic to make it appropriate for pediatric patients. Process and outcomes measures were monitored prospectively during a 6-month control and a 6-month intervention period. Mandatory use of the decision support tool was initiated for all antiinfective orders in a 26-bed PICU during the intervention period. Clinician opinions of the decision support tool were surveyed via questionnaire.

RESULTS

The rate of pharmacy interventions for erroneous drug doses declined by 59%. The rate of anti-infective subtherapeutic patient days decreased by 36%, and the rate of excessive-dose days declined by 28%. The number of orders placed per antiinfective course decreased 11.5%, and the robust estimate of the antiinfective costs per patient decreased 9%. The type of anti-infectives ordered and the number of antiinfective doses per patient remained similar, as did the rates of adverse drug events and antibiotic-bacterial susceptibility mismatches. The surveyed clinicians reported that use of the program improved their antiinfective agent choices as well as their awareness of impairments in renal function and reduced the likelihood of adverse drug events.

CONCLUSIONS

Use of the pediatric antiinfective decision support tool in a PICU was considered beneficial to patient care by the clinicians and reduced the rates of erroneous drug orders, improved therapeutic dosage targets, and was associated with a decreased robust estimate of antiinfective costs per patient. antiinfective agents, decision support systems, drug therapy, medication errors, child, infant.

A population-based assessment of pediatric all-terrain vehicle injuries

OBJECTIVE

To describe the types of injuries sustained by children who ride all-terrain vehicles (ATVs), to estimate the hospital charges associated with these injuries, and to determine adherence to existing rules and regulations governing ATV use.

METHODS

Analysis of statewide hospital admissions (1992-1996) and emergency department (ED) visits (1996) in Utah. All patients who were younger than 16 years and had an external cause of injury code for ATV use were included.

RESULTS

In 1996, 268 ED visits by children involved an ATV. Boys were twice as commonly injured as girls (male:female ratio: 2.1:1), and skin and orthopedic injuries were most frequent. The median ED charge was $368, and ED charges for these patients totaled $138 000. From 1992 to 1996, 130 children were hospitalized as a result of injuries sustained during ATV use, with median charges of $4240 per admission. Male to female ratio was 2.7:1, and the average age was 11.2 +/- 3.6 years. Mean injury severity score was 8.0 +/- 6.0, and median length of stay was 2 days (range: 0-43 days). Orthopedic injuries were most frequent, but 25% (n = 32) of children sustained head or spinal cord injury. Most children (94%) were discharged from the hospital, but 8 children died as a result of their injuries. Utah regulations prohibit children who are younger than 8 years from driving an ATV and advise against carrying passengers on ATVs. However, 25% (n = 15) of all injured children who were younger than 8 were driving the ATV when injured, and 15% (n = 60) of injured children were passengers on ATVs. Four of the 8 fatally injured children were younger than 8, and all were driving the ATV at the time of the crash. Finally, the estimated injury rate per 100 registered ATVs is significantly higher for children than for adults (3.41 vs 1.71).

CONCLUSIONS

ATV use results in significant injuries to children. Efforts to educate parents regarding the risks of ATV use, proper supervision, and use of safety equipment are warranted. Manufacturers of ATVs should continue to improve the safety profile of these inherently unstable vehicles.

Probabilistic record linkage: relationships between file sizes, identifiers and match weights

This study investigates relationships between file sizes, amounts of information contained in commonly used record linkage variables, and the amount of information needed for a successful probabilistic linkage project. We present an equation predicting the amount of information needed for a successful linkage project. Match weights for variables commonly used in record linkage are measured using artificially created databases. Linkage algorithms were successful when the sum of minimum weights for variables used in a linkage exceeded the predicted cutoff. Linkage results were acceptable when this sum was near the predicted cutoff. This technique enables researchers to determine if enough information exists to perform a successful probabilistic linkage.

Ability of hospitals to care for pediatric emergency patients

CONTEXT

The needs of children in emergency situations differ from those of adults and require special attention, yet there has been no study of the ability of U.S. hospitals to care for emergently or critically ill children.

OBJECTIVE

To estimate the distribution of pediatric services available at U.S. hospitals with emergency departments (EDs).

DESIGN

Self-report survey of 101 hospital EDs.

PARTICIPANTS

Stratified probability sample of all U.S. hospitals operating EDs.

RESULTS

The majority of hospitals that usually admit pediatric patients do not have separate pediatric facilities. Hospitals without a pediatric department, ward, or trauma service usually transfer critically injured pediatric trauma patients; however, nearly 10% of hospitals without pediatric intensive care facilities admit critically injured children to their own facilities. Likewise, 7% of hospitals routinely admit pediatric patients known to require intensive care to their adult intensive care units rather than transferring the patient to a facility with pediatric intensive care facilities. Few hospitals have protocols for obtaining pediatric consultation on pediatric emergencies. Appropriately sized equipment for successful care of infants and children in an emergency situation was more likely to be missing than adult-sized equipment, and significant numbers of hospitals did not have adequate equipment to care for newborn emergencies.

CONCLUSION

Emergent and critical care of infants and children may not be well integrated and regionalized within our health care system, suggesting that there is room for improvement in the quality of care for children encountering emergent illness and trauma.

Probabilistic linkage of computerized ambulance and inpatient hospital discharge records: a potential tool for evaluation of emergency medical services

STUDY OBJECTIVES

Emergency medical services (EMS) is an important part of the health care system. The effect of EMS on morbidity, mortality, and costs of illness is difficult to evaluate because hospital information is not available in out-of-hospital databases. We used probabilistic linkage to create such a database from ambulance and inpatient data and demonstrate the potential for linkage to facilitate evaluation of EMS responses resulting in hospital admission.

METHODS

Statewide ambulance and inpatient hospital discharge records were available for 1994 through 1996. Ambulance records indicating admission to the emergency department or hospital (165,649 records) were linked to inpatient hospital records indicating emergency admission (146,292 records) by using probabilistic linkage. Out-of-hospital data (dispatch code, treatments rendered, and ages), linkage rates, and inpatient data (discharge status, charges, length of stay, and payer category) were analyzed.

RESULTS

We linked 24,299 (14.7%) ambulance events to inpatient hospital discharges. If we had used exact linkage methods, we would have only linked 14,621 record pairs, a loss of nearly 40%. Linkage rates were relatively constant between years (approximately 15%) but differed by ambulance dispatch codes. Out-of-hospital dispatch codes with high linkage rates included breathing problems (22.6%), chest pain (21.5%), diabetic problems (16.9%), drowning incidents (14.9%), falls (19.2%), strokes (32.8%), and unconsciousness or fainting episodes (16.1%). Linkage to the hospital record provided access to hospital outcome data. Inpatient mortality was 6.8%. Survivors were discharged home (60.7%), transferred to other acute-care facilities (3.6%) or intermediate-care facilities (23.3%), or discharged with home health care provision (4.9%). The median length of stay was 3 days, and median charges were $6,620; total inpatient charges were $286,737,067.

CONCLUSION

Probabilistic linkage enables ambulance and hospital discharge records to be linked together and potentially increases our ability to critically evaluate EMS by providing access to hospital-based outcomes. Such evaluation will be further improved by linking to ED, other outpatient, and other public health data sources.

A population-based study of crashes involving 16- and 17-year-old drivers: the potential benefit of graduated driver licensing restrictions

OBJECTIVE

To evaluate the potential effectiveness of graduated driver licensing programs using population-based linked data for motor vehicle crashes (MVCs) that involved teenaged drivers (TDs).

METHODS

Utah crash, inpatient hospital discharge, and emergency department databases were analyzed and probabilistically linked. We computed hospital charges and compared violations, contributing factors, seatbelt use, and passengers for TDs (16-17 years old) relative to adult drivers (18-59 years old).

RESULTS

TDs comprised 5.8% of the study population, but were involved in 19.0% of MVCs. TD crashes resulted in $11 million in inpatient hospital charges and 158 fatalities. TD crashes were 1.70 times (95% confidence interval [CI]: 1.34, 2.04) less likely to result in fatal injury to drivers than were crashes that involved adult drivers, but TDs were 2.20 times (95% CI: 1.96, 2.47) more likely to receive citations. The following were findings of the study: 1) 11% of all TD crashes but 19% of fatal TD crashes occurred between 2200 and 0600 hours; 2) TDs used seatbelts less often than did adult drivers (79.1% vs 84.4%) and less often with passengers present (81.9% vs 75.0%; 3) TDs were 1.72 times (95% CI: 1.38, 2.14) more likely to be involved in crashes that resulted in seriously or fatally injured occupants when driving with passengers than when driving alone.

CONCLUSIONS

TDs are overrepresented in MVCs. TD crashes have a higher fatality rate at night, and TDs wear seatbelts less often than do adult drivers. Passengers affect TD crash characteristics. Graduated driver licensing programs that target state-specific characteristics of TDs may decrease morbidity and mortality.

Shoulder belts in motor vehicle crashes: a statewide analysis of restraint efficacy

The purpose of our study was to evaluate the impact of shoulder belt use on motor vehicle crash ejection, morbidity and mortality. We analyzed motor vehicle crash records linked to hospital inpatient data for front seat occupants of passenger cars in Utah between 1994 and 1996 (n = 103,035). Stochastic simulations were used to adjust for possible seatbelt misclassification. There were 276 (0.3%) occupants coded as using only a shoulder belt. The adjusted odds of ejection for shoulder only belted occupants was higher compared to lap-shoulder belted (odds ratio (OR) = 18.9; 95% confidence interval (CI) = 15.1, 25.1) and lap only belted occupants (OR = 4.3; 95% Cl = 2.9, 7.7). There was no difference in the odds of ejection for an occupant using a shoulder belt only and an occupant using no seatbelt (OR = 1.1; 95% CI = 1.0, 1.3). Occupants using a shoulder belt only were more likely to sustain a fatal or hospitalizing injury than lap-shoulder belted (OR = 2.3; 95% Cl = 1.9, 3.0), and lap only belted occupants (OR = 1.8; 95% CI = 1.3, 2.7), while controlling for other covariates. Occupants using only a shoulder belt had the same odds of a fatal or hospitalizing injury as unbelted occupants (OR = 1.1; 95% Cl = 0.9, 1.4). Average hospital inpatient length of stay, charges and injury severity scores were similar for all restraint types. These results stress the need for the use of a lap belt in conjunction with the shoulder belt.

Somatic growth and otolith growth in juveniles of a small subtropical flatfish, the fringed flounder, Etropus crossotus

A growth experiment was conducted with juvenile fringed flounder (Etropus crossotus) from North Inlet (South Carolina, USA) to provide information on the growth of a small, shortlived flatfish with a subtropical and tropical distribution. The fringed flounder has a maximum life span of 1.5 y and its long spawning period from March through October complicates the determination of growth rates based on length frequency data. Otoliths of juveniles with a standard length (SL) 23.1-53.0 mm were marked with Alizarin complexone and the fish were held in the laboratory for 66 days at 14, 20, 24 and 29 degrees C while being fed ad libitum. The mean somatic growth increased with temperature from 0.1 mm SL day(-1) at 14 degrees C to 0.4 mm SL day(-1) at both 24 and 29 degrees C. The maximum observed somatic growth rate was 0.7 mm SL day(1) at 29 degrees C. The number of micro-increments formed in otoliths was not significantly different from the expected value, validating formation of one increment per day. The significant relationship between increment width and somatic growth rate can be used to estimate somatic growth rates of individual wild fish based on daily increment information in their otoliths.

Adults and children in severe motor vehicle crashes: a matched-pairs study

STUDY OBJECTIVE

Many articles report seat belt injuries to children. This study examines the effect of child versus adult age and seat belt use on outcome in severe motor vehicle crashes.

METHODS

A population-based data set of all motor vehicle crashes statewide was analyzed by using matched-pairs logistic regression. Subjects were participants in motor vehicle crashes in which at least one occupant was killed or hospitalized and at least one was a child (age <15 years). Only passengers in cars, vans, and the front of light trucks were considered. Unique matched pairs were formed of one adult and one child from the same vehicle. The main outcome measure was death or hospitalization. Covariates were seat belt use and front or back seat position.

RESULTS

Overall, 413 pairs were analyzed. Seat belt use in these severe crashes was low for children and adults (40% versus 45%). Children more often sat in the back seat (74% versus 31% for adults). Risk of death was similar (7% for children and 8% for adults), but the percentage killed or hospitalized differed (13% for children and 28% for adults; odds ratio [OR] 2.5; 95% confidence interval [CI] 1.8 to 3.7). After controlling for seat belt use and seat position, adults remained at a similarly increased risk compared with children (OR 2.6; 95% CI 1.6 to 4.2). The back seat was much safer than the front seat (OR 5.5; 95% CI 3.7 to 8.1). An adult's nonuse of restraints was strongly predictive of a child's nonuse.

CONCLUSION

Seat belts were at least as protective for children as for adults, but only 40% of the children in these severe crashes were restrained.

Motor vehicle crash characteristics and medical outcomes among older drivers in Utah, 1992-1995

STUDY OBJECTIVE

We sought to compare the characteristics and medical outcomes of motor vehicle crashes for drivers 70 years and older with those of drivers between the ages of 30 and 39 years.

METHODS

We probabilistically linked statewide motor vehicle crash and hospital discharge data between the years of 1992 and 1995 for the state of Utah. We calculated the odds of older drivers exhibiting certain motor vehicle crash characteristics compared with younger drivers. Adjusting for nighttime crash, high-speed crash, and seatbelt use, we calculated the odds of an older driver being killed or hospitalized compared with those of a younger driver.

RESULTS

During the study years, there were 14,466 drivers older than 69 years and 68,706 drivers between the ages of 30 and 39 years involved in motor vehicle crashes in Utah. Older drivers were less likely to have crashes involving drug or alcohol use (odds ratio [OR] 0.1; 95% confidence interval [CI] 0.1 to 0.2) and less likely to have crashes at high speed (OR 0.6; 95% CI 0.6 to 0.7). Although older drivers were no more likely to have a crash involving a right-hand turn (OR 1.0; 95% CI 0.9 to 1.1) than younger drivers, they were over twice as likely to have a crash involving a left-hand turn (OR 2.3; 95% CI 2.2 to 2.5). Also, older drivers were more likely to be killed or hospitalized than younger drivers (OR, 3.5; P <.001). Among belted drivers, an older driver was nearly 7 times more likely to be killed or hospitalized than a younger driver (OR 6. 9; 95% CI 5.4 to 8.9).

CONCLUSION

Older drivers do have distinctive motor vehicle crash patterns. Interventions must be taken to reduce the number of left-hand turn crashes involving older drivers. In addition, further research is needed to design, implement, and evaluate countermeasures that may enable older drivers to continue driving while keeping public safety in the forefront.

Usage of emergency medical services by children with special health care needs

OBJECTIVE

To describe the usage of emergency medical services (EMS) by children with special health care needs (CSHCN).

METHODS

All EMS runs and related hospital records for children aged 0-17 years in Utah in 1991-92 were linked. The CSHCN status was determined from ICD-9 diagnoses using three available definitions. The amounts of EMS usage were compared between CSHCN and other children. A pediatric intensive care practitioner determined CSHCN status by chart review for 915 children transported by EMS to a pediatric tertiary care hospital, and his classification was compared with the CSHCN status assigned by the three ICD-9-based definitions.

RESULTS

The three definitions assigned CSHCN status for 2% to 24% of children using EMS. When compared with other children, CSHCN were more likely to be admitted to the hospital, more likely to use EMS for transfer between health care facilities, and more likely to receive prehospital procedures such as intravenous therapy. In the group of children whose charts were reviewed individually, one ICD-9-based definition most closely agreed to determination of CSHCN status by a pediatric intensive care practitioner.

CONCLUSIONS

Children with special health care needs who use EMS are more likely to receive advanced life support service, to receive prehospital procedures, and to be transferred from one health care facility to another. There is need for a specific and measurable definition of CSHCN that can be applied to existing health data.

Effect of seating position and restraint use on injuries to children in motor vehicle crashes

OBJECTIVE

To determine the effect of restraint use and seating position on injuries to children in motor vehicle crashes, with stratification by area of impact.

METHODS

Children <15 years old involved in serious automobile crashes in Utah from 1992 through 1996 were identified from statewide motor vehicle crash records. Serious crashes are defined as those resulting in occupant injuries with broken bones or significant bleeding or property damage exceeding $750. Probabilistic methods were used to link these records with hospital records. Analysis used logistic regression controlling for age, restraint use, occupant seating position, and type of crash.

RESULTS

We studied 5751 children and found 53% were rear seat passengers. More than 40% were unrestrained. Sitting in the rear seat offered a significant protective effect (adjusted odds ratio: 1.7; 95% confidence interval: 1.6-2.0), and restraint use enhanced this effect (adjusted odds ratio: 2.7; 95% confidence interval: 2.4-3.1). Mean hospital charges were significantly greater for front seat passengers.

CONCLUSIONS

Rear seat position during a motor vehicle crash provides a significant protective effect, restraint use furthers this effect, and usage rates of restraint devices are low. The rear seat protective effect is in addition to and independent of the protection offered from restraints.

Pre-hospital emergency medical services: a population based study of pediatric utilization

OBJECTIVES

To examine emergency medical services (EMS) usage by children in one state.

METHODS

Dispatch of an EMS vehicle in response to a call in the US is referred to as a "run". Runs for Utah for 1991-92 were linked to corresponding hospital records. Abbreviated injury severity scores (AISs) were assigned using ICDMAP-90 software.

RESULTS

For the two year period there were at least 15 EMS runs per 100 children per year, with incomplete reporting from rural areas. EMS response and scene times were similar for all age groups, but interventions were less frequent for children under 5 years of age. When the principal AIS region of injury was the head, neck, or face, cervical immobilization was less frequent for children less than 5 years of age (54%) than for older children (76%) and immobilization was associated with improved outcome, using the crude measure of lower hospital charges. There was a similar association between splinting of upper extremity fractures and reduced hospital charges. Both associations did not appear to be due to differences in injury severity.

CONCLUSIONS

The majority of EMS use by children is for trauma. Children less than 5 years of age are less likely to have an EMS intervention than older children. Whether the lower frequency of interventions is due to the lack of properly sized equipment on the vehicle, or to other factors, is undetermined.

Distinctive emergency department usage for injury for workers' compensation cases in Utah in 1996

To compare emergency department services paid by worker's compensation (WC) with services paid by other payers, a state database of 72,747 emergency department visits for injured adults (ages 21 to 54) in 1996 in Utah was analyzed. WC visits accounted for 21.6% (15,704) of all adult injury visits. The mean emergency department charge for WC visits was $282, and the admission rate was 17 per 1000 visits. The mean charge for other payers was $334, and the admission rate was 43 per 1000 visits. Differences were also found between these groups for Injury Severity Scores and diagnoses. In summary, WC emergency department usage was associated with less severe injuries than was emergency department usage for other payers in Utah in 1996.

Analysis of preventable pediatric trauma deaths and inappropriate trauma care in Montana

OBJECTIVE

To determine the rates of preventable mortality and inappropriate care, as well as the nature of treatment errors associated with pediatric traumatic deaths occurring in a rural state.

METHODS

Retrospective multidisciplinary consensus panel review of deaths attributed to mechanical trauma in children aged 18 years or less, occurring in Montana between October 1, 1989, and September 30, 1992. The care rendered in both preventable and nonpreventable cases was evaluated for appropriateness according to nationally accepted guidelines. Rates of pediatric preventable death and inappropriate care, as well as the nature of inappropriate care, were compared with that of the adult population.

RESULTS

One hundred thirty-eight cases were reviewed. One death (less than 1%) was judged frankly preventable, 11 deaths (8%) were judged possibly preventable, giving a total preventability rate of 9% for all cases reviewed. Considering only in-hospital deaths (n = 77), the total preventability rate was 16%. The rate of inappropriate care rendered for all deaths, regardless of preventability, was 36%. The rate of inappropriate care in the prehospital phase was 16%; for in-hospital deaths, it was 47%. In the emergency department (ED), the rate was 36%, and in post-ED care, 22%. In comparison to the adult population, the rates of preventable death (9% vs. 14%) and inappropriate care in the hospital phase (64% vs. 66%) were lower. Inappropriate care for the pediatric group was more prevalent in patients less than or equal to 14 years old. The nature of inappropriate care was most frequently associated with the management of respiratory problems, including airway control and management of chest trauma.

CONCLUSION

Preventable mortality from traumatic injuries in children in a rural state appears to be low, and lower than that reported for adult trauma victims in the same state. A preponderance of these preventable deaths occur in the subgroup of children less than or equal to 14 years if age. Inappropriate trauma care in children occurs frequently, particularly in the ED phase of care, and is primarily associated with the management of the airway and chest injuries. Education of ED primary care providers in basic principles of stabilization and initial treatment of the injured child 14 years old or younger may be the most effective method of reducing preventable trauma deaths in the rural setting.

The epidemiology of pediatric air medical transports in Utah

OBJECTIVE

To describe the air-transported patients treated at Primary Children's Medical Center (PCMC), the sole pediatric tertiary care center in Utah and a referral center in the intermountain region. This study describes the patients who utilized the air medical transport system, the medical services provided in the prehospital setting, and the corresponding charges for transport and treatment.

METHODS

Participants were air-transported patients aged 17 years and less who were treated at PCMC during the calendar years 1991-1992. The study population excluded patients who were transported to other medical facilities, and newborns. Data were abstracted retrospectively from the patients' medical and transport records. Data collected included demographic information, patient diagnoses, and treatments performed during transport. Financial data were supplied by the hospital.

RESULTS

During the study period, 874 pediatric patients met the participant criteria. Helicopter and fixed-wing transports comprised 561 and 313, respectively, from nine states in the mountain and western regions. The majority (313, 56%) of the patients transported by helicopter were trauma patients, while the majority (195, 62%) of fixed-wing transports were for illness-related conditions. Scene transports accounted for 120 (21%) of helicopter transports. Children with special health care needs accounted for 171 (20%) of all transports.

CONCLUSIONS

Injury severity scores indicate that, overall, air-transported patients were more severely injured than comparable ground-transported patients. However, it is apparent that some patients who were air-transported could have been transported by ground ambulance without detriment. medical services.

Priorities for research in Emergency Medical Services for Children: results of a consensus conference. EMSC Research Agenda Consensus Committee, National EMSC Resource Alliance

STUDY OBJECTIVE

The study objective was to arrive at a consensus on the priorities for future research in Emergency Medical Services for Children (EMSC).

METHODS

A consensus group was convened using the Rand'-UCLA Consensus Process. The group took part in a 3-phase process. Phase I involved reviewing a compendium of relevant research articles and answering a mailed questionnaire. Panel members were asked to prioritize topics based on the 1993 Institute of Medicine Report on Emergency Medical Services for Children. Participants were asked to rate each topic based on the significance of the research and whether the topic would (1) improve general knowledge, (2) change behavior, (3) improve health, (4) decrease the cost of care, or (5) change public policy. A 4-point Likert scale was used. They were also asked in the research would require a multicenter study and if the research were feasible. Round II of the study involved a meeting of the panel, where the results of Round I were discussed and the topics reprioritized. The topics were given a rank order and a final ranking was done in Round III.

RESULTS

The panel considered a list of 32 topics and these were combined and reworded to give them more precise meaning. Several new topics were also added. Fifteen topics were given a rank order and placed within the 7 broad categories of the Institute of Medicine report. Clinical aspects of emergency care systems organization, configuration and operation and injury prevention were given high priority rankings. The first 5 topics were very close in point-rank order.

CONCLUSION

The panel was able to develop a list of important topics for future research in EMSC that can be used by foundations, governmental agencies, and others in setting a research agenda for EMSC.

Critical pathways for postoperative care after simple congenital heart surgery

OBJECTIVE

To evaluate the clinical, financial, and parent/patient satisfaction impact of critical pathways on the postoperative care of pediatric cardiothoracic patients with simple congenital heart lesions.

STUDY DESIGN

Critical pathways were developed by pediatric intensive care nurses and implemented under the direction of pediatric cardiothoracic surgeons.

PATIENTS AND METHODS

Critical pathways were used during a 12-month study on 46 postoperative patients with simple repair of atrial septal defect (ASD), coarctation of the aorta (CoA), and patent ductus arteriosus (PDA). Using the study criteria, a control group of 58 patients was chosen from 1993. Prospective and control group data collected included postoperative intubation time, total laboratory tests, arterial blood gas utilization, morphine utilization, time in the pediatric intensive care unit, total hospital stay, total hospital charges, total hospital cost, and complications. Variances from the critical pathway and satisfaction data were also recorded for study patients.

RESULTS

Resource utilization was reduced after implementation of critical pathways. Significant reductions were seen in total hours in the pediatric intensive care unit, total number of laboratory tests, postoperative intubation times, arterial blood gas utilization, morphine utilization, length of hospitalization (ASD, 4.9 to 3.1 days; CoA, 5.2 to 3.2 days; and PDA, 4.1 to 1.4 days; all P < 0.05), total hospital charges (ASD, $16,633 to $13,627; CoA, $14,292 to $8319; and PDA, $8249 to $4216; all P < 0.05), and total hospital costs. There was no increase in respiratory complications or other complications. Patients and families were generally satisfied with their hospital experience, including analgesia and length of hospitalization.

CONCLUSIONS

Implementation of critical pathways reduced resource utilization and costs after repair of three simple congenital heart lesions, without obvious complications or patient dissatisfaction.

Priorities for research in emergency medical services for children: results of a consensus conference

STUDY OBJECTIVE

To arrive at a consensus on the priorities for future research in emergency medical services for children.

METHODS

A consensus group was convened using the Rand-UCLA Consensus Process. The group took part in a 3-phase process. Round 1 involved reviewing a compendium of relevant research articles and answering a mailed questionnaire. Panel members were asked to prioritize topics on the basis of the 1993 Institute of Medicine Report on Emergency Medical Services for Children. Participants were asked to rate each topic based on the significance of the research, and whether the topic would (1) improve general knowledge, (2) change behavior, (3) improve health, (4) decrease the cost of care, or (5) change public policy. A 4-point Likert scale was used. Participants were also asked if the research would require a multicenter study and if the research were feasible. Round 2 of the study involved a meeting of the panel, where the results of Round 1 were discussed and the topics were reprioritized. The topics were given a rank order and a final ranking was done in Round 3.

RESULTS

The panel considered a list of 32 topics; these were combined and reworded to give them more precise meaning. Several new topics were also added. Fifteen topics were given a rank order and placed within the 7 broad categories of the Institute of Medicine report. Clinical aspects of emergency care, systems organization, configuration, and operation and injury prevention were given high priority rankings. The first 5 topics were very close in point-rank order.

CONCLUSION

The panel was able to develop a list of important topics for future research in emergency medical services for children that can be used by foundations, governmental agencies, and others in setting a research agenda for such services.

Priorities for research in emergency medical services for children: results of a consensus conference

OBJECTIVE

To arrive at a consensus on the priorities for future research in emergency medical services for children.

METHODS

A consensus group was convened using the Rand-UCLA Consensus Process. The group took part in a 3-phase process. Round I involved reviewing a compendium of relevant research articles and answering a mailed questionnaire. Panel members were asked to prioritize topics on the basis of the 1993 Institute of Medicine Report on Emergency Medical Services for Children. Participants were asked to rate each topic based on the significance of the research, and whether the topic would (1) improve general knowledge (2), change behavior (3), improve health (4), decrease the cost of care, or (5) change public policy. A 4-point Likert scale was used. Participants were also asked if the research would require a multicenter study and if the research were feasible. Round II of the study involved a meeting of the panel, where the results of Round I were discussed and the topics were reprioritized. The topics were given a rank order and a final ranking was done in Round III.

RESULTS

The panel considered a list of 32 topics; these were combined and reworded to give them more precise meaning. Several new topics were also added. Fifteen topics were given a rank order and placed within the 7 broad categories of the Institute of Medicine report. Clinical aspects of emergency care, systems organization, configuration, and operation and injury prevention were given high priority rankings. The first 5 topics were very close in point-rank order.

CONCLUSION

The panel was able to develop a list of important topics for future research in emergency medical services for children that can be used by foundations, governmental agencies, and others in setting research agenda for such services.

Effect of a pediatric trauma response team on emergency department treatment time and mortality of pediatric trauma victims

OBJECTIVE

Delay in the provision of definitive care for critically injured children may adversely effect outcome. We sought to speed care in the emergency department (ED) for trauma victims by organizing a formal trauma response system.

DESIGN

A case-control study of severely injured children, comparing those who received treatment before and after the creation of a formal trauma response team.

SETTING

A tertiary pediatric referral hospital that is a locally designated pediatric trauma center, and also receives trauma victims from a geographically large area of the Western United States.

SUBJECTS

Pediatric trauma victims identified as critically injured (designated as "trauma one") and treated by a hospital trauma response team during the first year of its existence. Control patients were matched with subjects by probability of survival scores, and were chosen from pediatric trauma victims treated at the same hospital during the year preceding the creation of the trauma team.

INTERVENTIONS

A trauma response team was organized to respond to pediatric trauma victims seen in the ED. The decision to activate the trauma team (designation of patient as "trauma one") is made by the pediatric emergency medicine (PEM) physician before patient arrival in the ED, based on data received from prehospital care providers. Activation results in the notification and immediate travel to the ED of a pediatric surgeon, neurosurgeon, emergency physician, intensivist, pharmacist, radiology technician, phlebotomist, and intensive care unit nurse, and mobilization of an operating room team. Most trauma one patients arrived by helicopter directly from accident scenes.

OUTCOME MEASURES

Data recorded included identifying information, diagnosis, time to head computerized tomography, time required for ED treatment, admission Revised Trauma Score, discharge Injury Severity Score, surgical procedures performed, and mortality outcome. Trauma Injury Severity Score methodology was used to calculate the probability of survival and mortality compared with the reference patients of the Major Trauma Outcome Study, by calculation of z score.

RESULTS

Patients treated in the ED after trauma team initiation had statistically shorter times from arrival to computerized tomography scanning (27 +/- 2 vs 21 +/- 4 minutes), operating room (63 +/- 16 vs 623 +/- 27 minutes) and total time in the ED (85 +/- 8 vs 821 +/- 9 minutes). Calculation of z score showed that survival for the control group was not different from the reference population (z = -0.8068), although survival for trauma-one patients was significantly better than the reference population (z = 2.102).

CONCLUSION

Before creation of the trauma team, relevant specialists were individually called to the ED for patient evaluation. When a formal trauma response team was organized, time required for ED treatment of severe trauma was decreased, and survival was better than predicted compared with the reference Major Trauma Outcome Study population.

Innovation in the assessment of nursing theory and its evaluation: a team approach

In response to recent national changes in United Kingdom (UK) nurse education (e.g. devolution of assessment, moves to higher education, revision of the aims) and to local concerns (e.g. fairness to students, validity and reliability of written assessments, helping staff with less experience of assessment, student learning) an initiative has been developed at Southampton based on a team approach to marking and moderating. A five-stage evaluation was designed to accompany implementation of the initiative. The evaluation, carried out by a lecturer and an independent educational evaluator, involved both tutors/lecturers and students. Interviews, questionnaires and observation methods were used. Benefits of the initiative and of the particular model of evaluation included: increased knowledge and confidence in the validity and reliability of the marking and moderating process undertaken by tutor-teams; increased fairness to students; in-service tutor training related to student assessment; knowledge that assessment-promoted learning was taking place. A review of the total assessment programme was an unexpected outcome, including a review of the frequency and timing of assessments and of the written guidelines. The five-stage evaluation developed a feeling of involvement and heightened self-knowledge. Curricular understanding also increased; this helped to achieve the initiative as designed and intended. We recommend this model of evaluation; it promotes involvement of all concerned, students as well as staff, and generates valuable process-knowledge. It can be used in pre- and post-registration nurse education.

Albuterol in acute bronchiolitis--continued therapy despite poor response?

To determine whether clinicians continue to treat acute bronchiolitis with nebulized albuterol despite lack of clinical improvement after such treatment, we reviewed the medical records of 90 randomly selected infants and children with the primary diagnosis of that disorder who were treated in this 232-bed tertiary care children's hospital. Clinical improvement and no clinical improvement were defined as improvement and lack of improvement, respectively, in air movement, wheezing, retractions, oxygen saturation, work of breathing, and respiratory rate after administration of nebulized albuterol. Response to nebulized albuterol was determined from explicit written documentation in the medical records. Of 68 children who received nebulized albuterol in the emergency department, 52% had written documentation indicating no clinical improvement; however, 94% had admission orders to continue the therapy. Within 12 hours after admission, 61% were again noted to have no clinical improvement with nebulized albuterol. Eighty-seven percent of nonresponders continued to receive albuterol throughout hospitalization, and 54% continued to receive it after discharge. Continuing therapy despite lack of response resulted in unnecessary medical expenses.

Nonradiographic assessment of enteral feeding tube position

OBJECTIVE

To determine whether a clinical, nonradiographic criterion can be used to predict when the tip of a blindly placed feeding tube is in the small intestine.

DESIGN

Prospective sample.

SETTING

Pediatric intensive care unit at a tertiary care children's hospital.

PATIENTS

Critically ill children requiring transpyloric feeding.

INTERVENTIONS

The small bowel was intubated, using a blind, bedside transpyloric feeding tube placement protocol. The feeding tube was considered to be in the small bowel when <2 mL of a 10- mL aliquot of insufflated air could be aspirated from the feeding tube. This clinical criterion was confirmed with an abdominal radiograph.

MEASUREMENTS AND MAIN RESULTS

Patient age ranged from 1 month to 19 yrs (median 6 months). Weight ranged from 2.2 to 60 kg (median 4.9). Median time to feeding tube placement was 10 mins (range 5 to 60). Eighty-nine percent of the patients were mechanically ventilated, while 28% of these patients were pharmacologically paralyzed. Seventy-five feeding tubes were inserted. There were no known complications. Ninety-nine (74/75) percent of the feeding tubes were positioned in the small bowel. The inability to aspirate insufflated air correctly predicted small bowel intubation with 99% certainty (Sequential Probability Ratio Test, p = .05 and power = .80). This test incorrectly predicted the position of only one feeding tube, the 26th, which was in the stomach. Of the 74 feeding tubes positioned in the small bowel, 13 feeding tubes were in the duodenum and 61 were in the jejunum.

CONCLUSIONS

The inability to aspirate insufflated air confirms the transpyloric position of a feeding tube. Other clinical criteria did not successfully predict small bowel intubation. Use of this single test may obviate confirmatory abdominal radiographs in carefully selected patients and may lead to more cost-effective and timely initiation of enteral feedings.

Comparison of simultaneously obtained arterial and capillary blood gases in pediatric intensive care unit patients

OBJECTIVE

To determine whether capillary blood gas measurements provide a clinically acceptable estimate of arterial pH, PCO2, and PO2.

DESIGN

Prospective convenience sample.

SETTING

Pediatric intensive care unit at a referral children's hospital.

PATIENTS

Fifty children > 1 month of age with indwelling arterial catheters.

INTERVENTIONS

A local anesthetic was applied to the third finger of the hand contralateral to a radial artery catheter. After 90 mins, simultaneous arterial and capillary blood gases were drawn.

MEASUREMENTS AND MAIN RESULTS

Arterial and capillary pH, PcO2, and PO2 were measured. Heart rate and Wong/Baker faces score were noted before and during capillary blood gas collection to assess discomfort associated with blood collection. There was a strong correlation between capillary and arterial pH (r2 = .903, p < .0001). The relative average bias of the capillary pH was 0.009, with capillary lower than arterial and 95% limits of agreement of +/- 0.032. In all patients, the absolute value of the difference between arterial and capillary pH was < or = 0.05. There was a strong correlation between arterial and capillary PCO2 (r2 = .955, p < .0001). The relative average bias of the capillary PCO2 was 1.6 torr (0.21 kPa), with capillary higher than arterial and 95% limits of agreement of +/- 4.5 torr (+/- 0.6 kPa). In two of 50 patients, the absolute value of the difference between arterial and capillary PCO2 was > 6.5 torr (> 0.87 kPa). Despite a statistically significant correlation between capillary and arterial PO2 (r2 = .358, p < .0001), the absolute value of the difference between arterial and capillary PO2 was > 6.5 torr (> 0.87 kPa) in 42 of 50 patients. Pain, endotracheal intubation, vasoactive drips, or pharmacologic paralysis did not affect accuracy of the capillary pH or PCO2.

CONCLUSIONS

Capillary blood gases accurately reflect arterial pH and PCO2 in most pediatric intensive care unit patients. Capillary samples did not significantly underestimate arterial hypercarbia or acidosis. This conservative reflection of metabolic status may be particularly useful in hemodynamically stable patients with mild-to-moderate lung disease.

Characterization of recombinant soybean leghemoglobin a and apolar distal histidine mutants

The cDNA for soybean leghemoglobin a (Lba) was cloned from a root nodule cDNA library and expressed in Escherichia coli. The crystal structure of the ferric acetate complex of recombinant wild-type Lba was determined at a resolution of 2.2 A. Rate constants for O2, CO and NO binding to recombinant Lba are identical with those of native soybean Lba. Rate constants for hemin dissociation and auto-oxidation of wild-type Lba were compared with those of sperm whale myoglobin. At 37 degrees C and pH 7, soybean Lba is much less stable than sperm whale myoglobin due both to a fourfold higher rate of auto-oxidation and to a approximately 600-fold lower affinity for hemin. The role of His61(E7) in regulating oxygen binding was examined by site-directed mutagenesis. Replacement of His(E7) with Ala, Val or Leu causes little change in the equilibrium constant for O2 binding to soybean Lba, whereas the same mutations in sperm whale myoglobin cause 50 to 100-fold decreases in K(O2). These results show that, at neutral pH, hydrogen bonding with His(E7) is much less important in regulating O2 binding to the soybean protein. The His(E7) to Phe mutation does cause a significant decrease in K(O2) for Lba, apparently due to steric hindrance of the bound ligand. The rate constants for O2 dissociation from wild-type and native Lba decrease significantly with decreasing pH. In contrast, the O2 dissociation rate constants for mutants with apolar E7 residues are independent of pH, suggesting that hydrogen bonding to the distal histidine residue in the native protein is enhanced under acid conditions. All of these results support the hypothesis that the high affinity of Lba for oxygen and other ligands is determined primarily by enhanced accessibility and reactivity of the heme group.