[Perioperative infusion therapy in children : Are infusion sets with precision flow regulators suitable for pediatric anesthesia?] / Perioperative Infusionstherapie im Kindesalter : Eignen sich Infusionssysteme mit Laufratenbeschränkung für die Kinderanästhesie?

BACKGROUND: Infusion sets with precision flow regulators are frequently used in children undergoing surgery in order to control the perioperative administration of fluids. There are no data about the safety and accuracy of these infusion sets. A study was therefore conducted to compare adjusted and actual flow rates of three different infusion sets with precision flow regulators under standardized conditions. METHODS: The study evaluated three different infusion sets with precision flow regulators each at two different static levels. The actual flow rates of 5 infusions were recorded each time for adjusted flow rates of 50 ml/h, 100 ml/h, 150 ml/h, 200 ml/h and 250 ml/h over 1 h. Statistical analysis was performed with Excel (Excel, Microsoft Corporation, Redmond, WA, USA) and SOFA (Paton-Simpson and Associates Ltd., USA). The results are presented as means (standard deviation). RESULTS: For the adjusted flow rates of 50, 100, 150, 200 and 250 ml/h, actual flow rates were 107 (5.3), 174.8 (6.5), 255.8 (10.2), 312.4 (15.7) and 362.6 (20.2) ml/h for the Frekadrop® infusion set at a static level of 128 cm and 83.8 (4.4), 147.8 (5.5), 197 (12.4), 257.2 (4.97) and 311.6 (17.9) ml/h at a static level of 100 cm, respectively. For the Exadrop® infusion set actual flow rates were 88.6 (6.9), 131.2 (14.1), 224.4 (14.1), 296.6 (27.6) and 330.4 (22.4) ml/h at a static level of 128 cm and 54 (4), 82.4 (10.2), 138.8 (15.7), 209.4 (36.8) and 249 (12) ml/h at a static level of 76 cm, respectively. For the D-Flo infusion set actual flow rates were 95.6 (2.8), 167.6 (29), 217.8 (9.9), 281.6 (10.6) and 396.8 (37.5) ml/h at a static level of 128 cm and 69.2 (4.4), 110.2 (12.6), 169.2 (6), 205.2 (14) and 243 (15.9) ml/h at a static level of 80 cm, respectively. CONCLUSION: The actual flow rates differed considerably from the adjusted flow rates in the evaluated infusion sets. The flow rates substantially depended on the static level of the infusion. First and foremost, regulation of the administered infusion volume does not seem to be reliable when using an infusion set with a precision flow regulator.

Liquid-crystal order during synthesis affects main-chain liquid-crystal elastomer behavior.

This study presents the first direct comparison of the influence of liquid-crystal order during synthesis on the thermo-mechanical behaviors of main-chain liquid-crystal elastomers (LCEs) in thiol-acrylate networks. Six polydomain nematic elastomer (PNE) chemistries were compared directly by synthesizing with the mesogens in either an isotropic state (i-PNE) or a nematic state (n-PNE). The i-PNE networks were created in the presence of solvent, which disrupted any liquid-crystal order during network formation. Conversely, the n-PNE networks were created without the presence of solvent below the isotropic transition (TNI). Differential scanning calorimetry (DSC) was first performed, and it showed that i-PNE networks experienced a clearly defined nematic-to-isotropic transition upon heating, whereas the transition in n-PNE networks was unable to be identified, which may be the result of a nematic-to-paranematic phase transition. Dynamic mechanical analysis (DMA) tests revealed that while both networks maintained elevated loss tangent in the nematic region, only i-PNE networks prominently displayed dynamic soft elasticity behavior. The two-way shape switching behaviors of LCE networks were examined using actuation tests under a 100 kPa bias stress. It showed that the strain amplitude strongly depends on synthesis history; it ranges from 66% to 126% in i-PNE samples and 3% to 61% in n-PNE samples. To help interpret the different actuation strain behaviors between i-PNEs and n-PNEs, wide-angle X-ray scattering (WAXS) was then performed where the LCE samples were strained to 40%. The results showed that order parameter (S) in n-PNE samples (ranging from 0.37 to 0.50) is lower than that in i-PNE samples (0.54 for all cases), and the parameter decreased as the cross-linking density increased. The stress-strain behaviors of the LCE networks measured from uniaxial tension tests revealed that all i-PNE samples had a lower soft-elasticity plateau during loading compared to the n-PNE samples. Finally, free-standing strain recovery of LCE samples after being strained to 100% was investigated. Immediately after removing stress on the samples, i-PNE and n-PNE samples recovered 14% to 38% and 27% to 73% of strain, respectively. We discuss the advantages and disadvantages of the different synthetic histories on LCE design.

Preparation of Mealybugs (Hemiptera: Pseudococcidae) for Genetic Characterization and Morphological Examination.

Mealybugs (Hemiptera: Pseudococcidae) are economically significant agricultural pests on many different crops. Because of their small size and lack of easily visible characters for identification, determination of their taxonomic status is difficult and requires technical competency to prepare a slide-mounted specimen. The standard mounting technique does not allow for analysis of the genome of the specimen. Conversely, preparatory techniques for genetic analysis of mealybugs cause either loss of the entire individual or physical damage that can make morphology-based identification difficult. This study describes a simple protocol that does not impact physical integrity of the specimen for fixation and microscopic examination yet enables simultaneous DNA extraction for DNA-based identification of four mealybug species. All species prepared yielded high quality slide mounts, identified as Planococcus citri Risso, Pseudococcus viburni Signoret, Rhizoecus kondonis Kuwana, or Rhizoecus californicus Ferris. DNA extracted in this manner had higher purity and yield in the final eluate than in samples extracted using standard methods. DNA extracted was successfully amplified by polymerase chain reaction using primers for the cytochrome oxidase I gene and subsequently sequenced for all specimens. This protocol is likely to be applicable to other Hemiptera taxa that are preserved by slide mounting, allowing for both the preparation of a high-quality voucher specimen for morphological identification and simultaneous analysis of DNA for the same specimen. The methods used are technically less challenging than current standard procedures.

Transfer of airway skills from manikin training to patient: success of ventilation with facemask or LMA-Supreme(TM) by medical students.

During emergency care, the ability to ventilate the patient's lungs is a crucial skill. Supraglottic airway devices have an established role in emergency care, and manikin trials have shown that placement is easy even for inexperienced users. However, there is current discussion as to what extent these results can be transferred to patients. We studied the transfer of skills learnt on a manikin to the clinical situation in novice medical students during their anaesthesia rotation. They were required to ventilate the lungs of a manikin using a facemask and then position a supraglottic airway device (LMA-Supreme™) and ventilate the lungs. This process was then repeated on anaesthetised patients, with standard ventilator settings to assess adequacy of ventilation. Sixty-three students participated in the manikin study. The success rate for ventilating the lungs was 100% for both devices, but the mean (SD) time to achieve successful ventilation was 27.8 (24.4) s with the facemask compared with 38.6 (22.0) s with the LMA-Supreme (p = 0.008). Fifty-one of the students progressed to the second part of the study. In anaesthetised patients, the success rate for ventilating the lungs was lower for the facemask, 27/41 (66%) compared with the LMA-Supreme 37/41 (90%, p = 0.006). For 26 students who succeeded with both devices, the tidal volume was lower using the facemask, 431 (192) ml compared with the LMA-Supreme 751 (221) ml (p = 0.001), but the time to successful ventilation did not differ, 60.0 (26.2) s vs 57.3 (26.6) s (p = 0.71). We conclude that the results obtained in manikin studies cannot be transferred directly to the clinical situation and that guidelines should take this into account. Based on our findings, a supraglottic airway device may be preferable to a facemask as the first choice for inexperienced emergency caregivers.

What constitutes high quality of care for adults with epilepsy?

BACKGROUND: Providers are increasingly being held accountable for the quality of care provided. While quality indicators have been used to benchmark the quality of care for a number of other disease states, no such measures are available for evaluating the quality of care provided to adults with epilepsy. In order to assess and improve quality of care, it is critical to develop valid quality indicators. Our objective is to describe the development of quality indicators for evaluating care of adults with epilepsy. As most care is provided in primary and general neurology care, we focused our assessment of quality on care within primary care and general neurology clinics. METHODS: We reviewed existing national clinical guidelines and systematic reviews of the literature to develop an initial list of quality indicators; supplemented the list with indicators derived from patient focus groups; and convened a 10-member expert panel to rate the appropriateness, reliability, and necessity of each quality indicator. RESULTS: From the original 37 evidence-based and 10 patient-based quality indicators, the panel identified 24 evidence-based and 5 patient-based indicators as appropriate indicators of quality. Of these, the panel identified 9 that were not necessary for high quality care. CONCLUSION: There is, at best, a poor understanding of the quality of care provided for adults with epilepsy. These indicators, developed based on published evidence, expert opinion, and patient perceptions, provide a basis to assess and improve the quality of care for this population.

[Diagnosis and outcome of neurotropic enterovirus infections in childhood]. / Diagnostik und klinischer Verlauf neurotroper Enterovirusinfektionen im Kindesalter.

BACKGROUND: Enterovirus infections are among the most common causes of aseptic meningitis. Worldwide there are reports about recurring outbreaks, especially during the summer. They are favoured by conditions of bad hygiene and contaminated water, transmission is predominantly through the faeco-oral route or by droplet infection. The most common species are Coxsackie B and ECHO (Enteric Cytopathogenic Human Orphan) virus. ECHO viruses have a worldwide distribution and usually occur as "summer flu" or aseptic meningitis and meningoencephalitis in toddlers and infants. Type 30 caused an outbreak of aseptic meningitis in the Rhein-Main region in summer 1997. During five months 63 children younger than 16 years were reported. PATIENTS AND METHODS: During this outbreak 18 children with prooved enterovirus infections were treated at the Frankfurt/Main University Children's Hospital. Standardized infectiological diagnostic procedures were performed and risc factors, clinical symptoms, inflammatory marker, neurophysiological findings (electroencephalography, evoked potentials) and outcome were assessed. RESULTS: The affected children were between 3 and 11 years old. Clinical symptoms were cephalgia, nausea, vomiting, meningism and seizures with fever. Virus isolation from faecal and cerebrospinal fluid (CSF) samples and the use of polymerase chain reaction (PCR) was superior to serological methods. Erythrocyte sedimentation rates showed more significant increase than C-reactive protein (CRP) and blood leukocytes. CSF pleocytosis showed high variation. Clinical course as well as prognosis and outcome were favourable. CONCLUSION: Virusisolation in stool and CSF is most promising in the diagnostic of cerebral enterovirus infections. Usually the outcome is favourable, encephalitis can occur as serious complication.

One-dimensional metallic edge states in MoS2.

By the use of density functional calculations it is shown that the edges of a two-dimensional slab of insulating MoS2 exhibit several metallic states. These edge states can be viewed as one-dimensional conducting wires, and we show that they can be observed directly using scanning tunneling microscopy for single-layer MoS2 nanoparticles grown on a support.

Midline developmental anomalies with lipomas in the corpus callosum region.

Three children with complete or partial callosal aplasia and intracranial lipoma in the corpus callosum region were investigated. Two lipomas were tubulonodular; one replaced the entire corpus callosum structure. Accompanying anomalies affected the cingulate gyrus, septum pellucidum, and choroid plexus. In one case, diagnosis was made in utero in the 25th gestational week by ultrasonography; in the second case it was made on the first day of life, also by screening ultrasonography. Two children had mild spastic distal diparesis; one complained of chronic headache. Electroencephalography showed no abnormalities; epilepsy anamnesis was negative. Somatosensory and visual evoked potentials showed prolonged conduction in two cases. Surgery was not indicated. Because of the risk of developing epileptic seizures, regular electroencephalographic follow-up investigations are essential.

Luminol/H2O2 chemiluminescence detector for the analysis of nitric oxide in exhaled breath.

A new instrument for the detection of nitric oxide has been developed and applied to the analysis of exhaled breath. The instrument is based on conversion of NO to NO2, using the oxidant chromium trioxide, followed by detection of chemiluminescence in the reaction of NO2 with an alkaline luminol/H2O2 solution. The presence of H2O2 is found to enhance the sensitivity of NO2 detection by a factor of approximately 20. A bundle of porous polypropylene hollow fiber membranes is used to bring the gaseous sample into contact with the luminol solution. Chemiluminescence occurring within the translucent hollow fibers is detected using a miniature photomultiplier tube. The limit of detection for NO is 0.3 ppbv for S/N = 3, and the 1/e response time is 2 s. A large interference resulting from the 4-6% CO2 concentration in exhaled breath is removed by use of an ascarite scrubber in the air stream. Breath measurements of NO were made using a sampling technique developed by Sensor Medics (Yorba Linda, CA) with simultaneous detection using the luminol/H2O2 and NO + O3 chemiluminescence techniques. The two instruments were found to be in excellent agreement. Nitric oxide levels were in the range 6.0-22.0 ppbv for healthy individuals and 40.0-80.0 ppbv for individuals with asthma or a respiratory infection. This new detector offers the advantages of compact size, low cost, and a simple configuration compared to NO detectors based on NO + O3 chemiluminescence.

Protamine allergy as a complication of insulin hypersensitivity: A case report.

BACKGROUND: Although most patients receiving insulin produce insulin-specific IgE, significant allergic symptoms develop in very few of them. Patients receiving neutral protamine Hagedorn (NPH) insulin are at increased risk for the development of protamine hypersensitivity. The case of a 19-year-old woman with insulin-dependent diabetes and regular and NPH insulin hypersensitivity is presented. OBJECTIVE: The purpose of this study was to determine whether desensitization to NPH insulin, as well as standard insulin desensitization, could control allergic symptoms in a patient allergic to both NPH and regular insulin. METHODS: The patient required insulin desensitization for severe urticaria, angioedema, and occasional wheezing resulting from her insulin dose. She underwent a standard protocol for insulin desensitization twice in a 2-month period, with persistence in her symptoms. She was found to have high protamine-specific, as well as insulin-specific, IgE levels, and because of her poor response to regular insulin desensitization, she was desensitized to both regular and NPH insulin. RESULTS: Dual desensitization resulted in marked improvement in her symptoms. The patient had recurrence of urticaria and angioedema a year and a half later, at which point the NPH was stopped and she was desensitized to regular insulin. She continued to receive regular insulin 4 times per day over the following 3 years with only occasional hives. CONCLUSION: Patients with insulin allergy may not have complete resolution of their symptoms after standard desensitization, particularly those patients with concomitant protamine allergy. These patients may require protamine/NPH desensitization, an alternative insulin preparation, or both.

[Nervous system manifestations in HIV infected children]. / Affektionen des Nervensystems bei perinatal HIV-infizierten Kindern.

In 34 perinatally HIV infected children time of manifestation, type and treatability of neurologic disorders were investigated for a period of 7 years (1987-1994). Neurological investigations were done every 6 months; EEG and MRI/CT were examined initially in the asymptomatic stage and were repeated when neurologic Symptoms occurred. Zidovudine therapy was started after onset of symptoms, dosage was raised, when treatment with Zidovudine had already begun (600-720 mg/m2/day). Various neurological manifestations were seen in 4 of 12 patients in stage B (33%) and in 11 of 14 children in AIDS (80%). 7 of the 14 AIDS-patients (50%) developed a subacute progressive course or progressive plateau course and 4 of 14 (30%) a static course of encephalopathy. Pathological changes in EEG were seen in 54% of investigated patients with neurological deficits. Neuroimaging revealed pathological findings in all symptomatic subjects, 6 of 11 patients in AIDS (55%) has a severe general cerebral atrophy and multifocal white matter lesions. Zidovudine had a positive temporary effect from 6 to 12 months in 5 of 11 treated patients (45%). At present a thorough neurological examination is the most sensitive method to detect neurological impairment in HIV infected children. In most cases CT/MRI scan provides information about the course of the encephalopathy. Antiretroviral therapy has a limited benefit, if neurologic symptoms start after the second year of life.

Cat antigen in homes with and without cats may induce allergic symptoms.

Although Fel d 1, the major cat allergen, has been found in settled dust samples from homes both with and without cats, the clinical relevance of this allergen has never been studied. In this study we measured airborne concentrations of Fel d 1 in homes both with and without cats and then attempted to relate these levels to those obtained in our experimental cat challenge model to assess their clinical significance. In baseline samples we found measurable levels of airborne Fel d 1 in all 37 homes with cats (range, 1.8 to 578 ng/m3; median, 45.9 ng/m3) and in 10 of the 40 homes without cats (for detectable samples: range, 2.8 to 88.5 ng/m3; median, 17 ng/m3). Fel d 1 was present in the settled dust of 38 of 40 homes without cats (range, 39 to 3750 ng/gm; median, 258 ng/gm), although these levels were only weakly predictive of airborne levels. Repeat samples obtained weekly from 12 homes without cats yielded measurable airborne levels. Fel d 1 in at least one of the four samples from all homes. When compared with challenges performed in our cat room facility at low levels of airborne Fel d 1 (<500 ng/m3), these home levels are within the range capable of causing upper and lower respiratory symptoms in subjects allergic to cats. We therefore conclude that the low level cat exposure that occurs in many homes without cats is capable of inducing symptoms in some patients who are sensitive to cats. The assessment of cat exposure should not be based solely on the presence or absence of a cat in the home.

[Congenital candida infections]. / Kongenitale Candidainfektionen.

Congenital candida infection is a rare disease, although the incidence of candida vaginitis during pregnancy is high. We report on five cases each showing patterns considered typical for candida infection. The infective agent can cause chorioamnionitis even in the presence of intact fetal membranes. An intrauterine device (IUD) has been proved to be a risk factor for a congenital candida infection. The pathogenetic significance of contamination with candida for the fetus appears to depend largely on gestational age. A premature infant with a birth-weight less than 1500 g presented with bilateral candida endophthalmitis which was cured by intravenous Fluconazole therapy. Another premature infant weighing 800 g at birth developed a systemic candida infection. The other three more mature infants had milder symptoms, two of them presented with cutaneous candidiasis.

Serious assaults by inpatients.

Forty-nine hospital wards in the United States and Canada were surveyed during specified periods for one year to document assaults by inpatients on staff or other patients. Nine (5.7%) of the 158 assaults by adult psychiatric inpatients were sufficiently severe to require medical treatment. Four others occurred on the only children's service studied. Only one (2.6%) of 39 assaults on adult nonpsychiatric units required medical care. Injuries were rarely serious, with only four assaults in any setting leading to bedrest or missed workdays. The overall rate of assault (assaults per bed per year) on 27 adult psychiatric units was 1.36; for assaults requiring treatment, the rate was 0.08. The rate of assault of any kind on 22 adult nonpsychiatric units was 0.28 assaults per bed per year.

Randomized trial of ciprofloxacin compared with other antimicrobial therapy in the treatment of osteomyelitis.

Thirty adults (mean age, 52 years) were enrolled in a randomized, comparative trial of oral ciprofloxacin (750 mg twice daily) and other antimicrobial therapies. Etiologic agents included Enterobacteriaceae (18 isolates), Pseudomonas aeruginosa (16 isolates), and Staphylococcus aureus (four isolates). Seven of 14 (50 percent) ciprofloxacin-treated infections are cured at up to 13 months follow-up and three infections appear improved. Treatment failure or relapse has occurred in four patients. Sixteen patients received other antimicrobial therapy and 11 patients (65 percent) remain without infection and have healed wounds, with follow-up from one to 13 months. One patient has had a relapse, while improvement is apparent in four patients. Complications that occurred in this group included drug-related neutropenia (two patients), diarrhea (two patients), drug allergy (one patient), and catheter-related staphylococcal cellulitis (one patient). Oral ciprofloxacin therapy for chronic osteomyelitis caused by susceptible organisms appears to be as effective as other antimicrobial therapies.

Dexamethasone inhibits the antigen-induced contractile activity and release of inflammatory mediators in isolated guinea pig lung tissue.

Treatment for 24 h in vitro with dexamethasone inhibited the antigen-induced contractile response in guinea pig tracheal rings and parenchymal strips without inhibiting the contractile response of the tissues to either methacholine or histamine, respectively. Antigen-induced histamine release was inhibited by approximately 50% in both tissues by prior treatment with dexamethasone. Dexamethasone treatment also inhibited the release of immunoreactive sulfidopeptide leukotriene from parenchymal strips. In tracheal rings, dexamethasone treatment reduced spontaneous release of all cyclooxygenase metabolites (PGE2, PGF2 alpha, TXB2, PGD2, and 6-k-PGF1 alpha were tested), with the exception of PGD2, and also inhibited the antigen-induced release of all cyclooxygenase metabolites studied. Dexamethasone-treatment did not inhibit the spontaneous release of cyclooxygenase metabolites in the guinea pig lung strips, and only modestly inhibited the antigen-induced release of PGE2, PGF2 alpha, and PGD2. The results suggest that the inhibition of contractile response of guinea pig lung strips and airway tissue to antigen by dexamethasone is the result of a reduced release of inflammatory mediators. The inhibition by dexamethasone of antigen-induced release of mast cell mediators from guinea pig lung parenchyma contrasts with results previously obtained with human parenchymal lung tissue.