bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of cuffed and uncuffed preformed oral pediatric tracheal tubes
Authors: WEISS MARKUS , BERNET VERA , STUTZ KATHARINA , DULLENKOPF ALEXANDER , MAINO PAOLO 
Published: February 2006

SummaryBackground : In preformed cuffed tracheal tubes the position of the cuff within the airway is given by its distance to the tube bend placed at the lower teeth. The aim of this study was to compare the design of cuffed and uncuffed preformed pediatric oral tracheal tubes with regard to anatomical landmarks.Methods : Complete series of cuffed and uncuffed preformed oral pediatric tracheal tubes sized from internal diameter 3.0–7.0 mm if available were ordered from five different manufacturers. The distance from the bend to the distal tube tip and to the upper border of the cuff were measured and compared with anatomical airway landmarks in the developing child.Results : Between cuffed and uncuffed tracheal preformed tubes up to 37 mm differences in the bend‐to‐tracheal tube tip distances were found for given age groups. Thus uncuffed preformed tracheal tubes were more at risk for inadvertent endobronchial intubation than cuffed preformed tracheal tubes. Comparison of bend‐to‐upper border of the cuff distances with teeth‐to‐vocal cord distances calculated from anatomical data revealed that several of the tracheal tube cuffs become positioned within the subglottic larynx or even within the vocal cords when inserted according to the bend.Conclusions : There is a need for improvement in cuffed preformed pediatric tracheal tubes, namely a standard bend‐to‐tracheal tube tip distance to allow a safe insertion depth, a short cuff placed on the tube shaft as distally as possible and an intubation depth mark to verify a proper position of the cuff in the trachea.
A comparative study of hemodynamic responses to orotracheal intubation with fiberoptic bronchoscope and laryngoscope in children
Authors: XUE F.S. , ZHANG G.H. , SUN H.T. , LI C.W. , LI P. , LIU K.P. , XU Y.C. , LIU Y. , LIU J. 
Published: February 2006

SummaryBackground : The purposes of this study were to further identify the hemodynamic responses to orotracheal intubation in children, using a fiberoptic bronchoscope (FOB) and a direct laryngoscope (DLS), and to validate whether the FOB can attenuate the hemodynamic response to orotracheal intubation compared with the DLS.Methods : Forty‐three children, ASA PS I–II scheduled for elective plastic surgery under general anesthesia requiring orotracheal intubation were randomly allocated to either the DLS group (n = 20) or the FOB group (n = 23). Noninvasive systolic blood pressure (SBP) and heart rate (HR) were recorded before (baseline values) and after anesthesia induction (postinduction values), at intubation and every minute for the first 5 min after intubation. The maximal values of SBP and HR during the observation were also recorded. The product of HR and SBP [rate pressure product (RPP)] at each time point was calculated.Results : In the DLS group, SBP, HR, and RPP at intubation and 1 min after intubation were significantly higher than postinduction values, but did not exceed baseline values. In the FOB group, SBP, HR, and RPP at intubation increased significantly compared with baseline and postinduction values. In the two groups, the maximal values of SBP, HR, and RPP during the observation were significantly higher than baseline values. Except for the HR at intubation, there were no significant differences in other hemodynamic parameters during the observation and the time required to reach maximal values of SBP, HR, and RPP between the two groups.Conclusions : Orotracheal intubation using FOB and DLS in children may cause similar increases in SBP and HR. Compared with the DLS, the FOB had no advantage in attenuating the hemodynamic responses to orotracheal intubation.
Impact of a nurse practitioner‐assisted preoperative assessment program on quality
Authors: VARUGHESE ANNA M. , BYCZKOWSKI TERRI L. , WITTKUGEL ERIC P. , KOTAGAL UMA , DEAN KURTH C. 
Published: February 2006

SummaryBackground : The anesthesia manpower shortage in the last few years in the US has limited many hospital pediatric surgical services. We sought to meet an increasing surgical caseload, while providing safe, timely and patient‐centered care by instituting a nurse practitioner‐assisted preoperative evaluation (NPAPE) program. The strategic goal of this program was to shift anesthesiologists from the preanesthesia clinic to the operating room (OR), while maintaining the quality of preoperative care. Our study sought to evaluate the quality of the NPAPE program.Methods : One thousand five hundred and nine children aged 1 month–18 years, 463 parents, 25 anesthesiologists and 20 preoperative clinic nurses were studied. Indicators of quality were incidence of respiratory complications (apnea/hypopnea, laryngospasm, bronchospasm, and supplemental oxygen use in postanesthesia care unit), patient preoperative preparation time and parent and staff (anesthesiologists and preoperative clinic nurse) satisfaction. These indicators were recorded for 1 week every 3 months for 1 year. The first week (baseline) was an anesthesiologist‐only preoperative assessment (three anesthesiologists performing approximately 120 evaluations per day). The subsequent four data collection weeks at 3, 6, 9, and 12 months were nurse practitioner (NP)‐aided preoperative assessments (one anesthesiologist with six NPs performing approximately 120 evaluations per day).Results : The incidence of respiratory complications, patient preoperative preparation time, and levels of parental satisfaction did not differ significantly between anesthesiologist‐only and NP‐aided assessments. However, anesthesiologist and preoperative clinic nurse satisfaction increased significantly postimplementation of the program.Conclusions : Our study revealed that within a year of its implementation, the NPAPE program maintained patient safety, timeliness, and a high level of parent satisfaction as well as increased staff satisfaction, while shifting two anesthesiologists to the OR. A NP‐assisted preoperative evaluation program can offer operational advantages without compromising care.
Monitored anesthesia care with a combination of ketamine and dexmedetomidine during magnetic resonance imaging in three children with trisomy 21 and obstructive sleep apnea
Authors: LUSCRI NATHAN , TOBIAS JOSEPH D. 
Published: February 2006

SummaryWe present a series of three children with trisomy 21 and obstructive sleep apnea who required sedation during magnetic resonance imaging of the upper airway. In an effort to provide effective sedation with limited effects on cardiovascular and ventilatory function, sedation was provided by a combination of ketamine and dexmedetomidine. Sedation was initiated with a bolus dose of ketamine (1 mg·kg−1) and dexmedetomidine (1 μg·kg−1) and maintained by a continuous infusion of dexmedetomidine (1 μg·kg−1·h−1). One patient required a repeat of the bolus doses of ketamine and dexmedetomidine and an increase of the dexmedetomidine infusion to 2 μg·kg−1· h−1. Effective sedation was provided for all three patients. We noted no clinically significant hemodynamic or respiratory effects. No central apnea was noted although there was a brief episode of upper airway obstruction in one patient which responded to repositioning of the airway. All three patients developed some degree of hypercarbia with maximum PEco2 values of 6.4, 6.9, and 6.8 kPa (49, 53, and 52 mmHg), respectively. To date, this is the first report regarding the use of this combination in pediatric patients. Given the preliminary success noted in our three patients, prospective trials evaluating the efficacy of a dexmedetomidine–ketamine combination appears warranted.
Airway management of three cases of congenital cervical teratoma
Authors: HULLETT BRUCE J. , SHINE NEVILLE P. , CHAMBERS NEIL A. 
Published: February 2006

SummaryCervical teratomas are rare congenital tumors derived from all three germ cell layers. The vast majority are histologically benign, but the significant size they may attain can potentiate life‐threatening upper airway obstruction. All cases require the specialist airway skills of the pediatric anesthetist. This may be planned, in the case of antenatally diagnosed lesions, when the pediatric anesthetist is part of a multidisciplinary team involved in an EX utero Intrapartum Treatment (EXIT) or Operation On Placental Support (OOPS) procedure, or when a neonate is undergoing elective excision in the early neonatal period as definitive treatment. Alternatively the anesthetist may be called upon urgently to secure a compromised airway immediately postpartum when no antenatal diagnosis has been made. Furthermore, after elective surgical excision, airway compromise is possible, which may again require anesthetic intervention. The aim of this study is to report the authors’ experience in managing the airway in three cases of congenital cervical teratoma in the study institution over the last 24 months. These cases highlight the possible airway scenarios that may confront the anesthetist in the immediate postpartum, elective surgery and postoperative stages and the variety of techniques that may be employed in order to overcome the potential difficulties encountered.
Association of oculocardiac reflex and postoperative nausea and vomiting in strabismus surgery in children anesthetized with halothane and nitrous oxide
Authors: KARANOVIC NENAD , CAREV MLADEN , UJEVIC ANTE , KARDUM GORAN , DOGAS ZORAN 
Published: February 2006

SummaryBackground: Postoperative nausea and vomiting (PONV) occurs frequently after strabismus surgery. The controversy still exists regarding the association of PONV and the oculocardiac reflex (OCR). A recent study has proven that rocuronium attenuates OCR. If these two occurrences are dependent, it is expected that with the diminution of OCR, occurrence of PONV will also be reduced. The goal of this randomized, controlled study was to prove an association between OCR and PONV by attenuating OCR with 0.4 mg·kg−1of rocuronium and subsequently diminishing PONV if these occurrences are associated.Methods: A total of 119 ASA 1 children, aged between 3 and 10, undergoing surgery of the medial rectus muscle, were randomly assigned to two groups. In group R (n = 59), 0.4 mg·kg−1of rocuronium was administered i.v. before intubation. Group C (controls,n = 60) received no muscle relaxant. The anesthesia was induced and maintained with halothane and N2O/O2(50/50%). Chi‐squared test, Fisher's exact test,t‐test, andanovawere used for statistical analysis;P‐value <0.05 was considered statistically significant.Results: There were no differences between groups regarding patients’ characteristics as well as endtidal halothane and duration of surgery and anesthesia. The occurrence of OCR was different between groups (R: 16/59, 27.1%, C: 28/60, 46.7%;P = 0.027), but not the occurrence of PONV (R: 27/59, 45.8%, C: 28/60, 46.7%;P = 0.921). There was an equal number of patients with PONV and bradycardias in both groups (R: 4/27 vs C: 4/28;P = 0.858), whereas there was different, but statistically insignificant distribution of patients (R: 3/27 vs C: 10/28;P = 0.086) with PONV and arrhythmias other than bradycardia. However, simultaneous occurrence of total OCR and PONV in the 24‐h period was not different between the two groups (P = 0.964).Conclusions: Rocuronium (0.4 mg·kg−1) attenuates the occurrence of OCR, but with the reduced occurrence of OCR we were not able to attenuate the occurrence of PONV, therefore the association of OCR and PONV in strabismus surgery in children anesthetized with halothane and nitrous oxide remains unclear, and if there is a link between the two, it could be related to arrhythmias and not bradycardia.
Minimum viable population sizes and global extinction risk are unrelated
Authors: Brook Barry W. , Traill Lochran W. , Bradshaw Corey J. A. 
Published: February 2006

AbstractTheoretical and empirical work has shown that once reduced in size and geographical range, species face a considerably elevated risk of extinction. We predict minimum viable population sizes (MVP) for 1198 species based on long‐term time‐series data and model‐averaged population dynamics simulations. The median MVP estimate was 1377 individuals (90% probability of persistence over 100 years) but the overall distribution was wide and strongly positively skewed. Factors commonly cited as correlating with extinction risk failed to predict MVP but were able to predict successfully the probability of World Conservation Union Listing. MVPs were most strongly related to local environmental variation rather than a species’ intrinsic ecological and life history attributes. Further, the large variation in MVP across species is unrelated to (or at least dwarfed by) the anthropogenic threats that drive the global biodiversity crisis by causing once‐abundant species to decline.
Ecosystem allometry: the scaling of nutrient stocks and primary productivity across plant communities
Authors: Kerkhoff Andrew J. , Enquist Brian J. 
Published: February 2006

AbstractA principal challenge in ecology is to integrate physiological function (e.g. photosynthesis) across a collection of individuals (e.g. plants of different species) to understand the functioning of the entire ensemble (e.g. primary productivity). The control that organism size exerts over physiological and ecological function suggests that allometry could be a powerful tool for scaling ecological processes across levels of organization. Here we use individual plant allometries to predict how nutrient content and productivity scale with total plant biomass (phytomass) in whole plant communities. As predicted by our model, net primary productivity as well as whole community nitrogen and phosphorus content all scale allometrically with phytomass across diverse plant communities, from tropical forest to arctic tundra. Importantly, productivity data deviate quantitatively from the theoretically derived prediction, and nutrient productivity (production per unit nutrient) of terrestrial plant communities decreases systematically with increasing total phytomass. These results are consistent with the existence of pronounced competitive size hierarchies. The previously undocumented generality of these ‘ecosystem allometries’ and their basis in the structure and function of individual plants will likely provide a useful quantitative framework for research linking plant traits to ecosystem processes.
Predator disease out‐break modulates top‐down, bottom‐up and climatic effects on herbivore population dynamics
Authors: Wilmers Christopher C. , Post Eric , Peterson Rolf O. , Vucetich John A. 
Published: February 2006

AbstractHuman‐introduced disease and climatic change are increasingly perturbing natural ecosystems worldwide, but scientists know very little about how they interact to affect ecological dynamics. An outbreak of canine parvovirus (CPV) in the wolf population on Isle Royale allowed us to test the transient effects of an introduced pathogen and global climatic variation on the dynamics of a three‐level food chain. Following the introduction of CPV, wolf numbers plummeted, precipitating a switch from top‐down to bottom‐up regulation of the moose population; consequently, the influence of climate on moose population growth rate doubled. This demonstrates that synergistic interactions between pathogens and climate can lead to shifts in trophic control, and suggests that predators in this system may play an important role in dampening the effects of climate change on the dynamics of their prey.
Parent birds assess nest predation risk and adjust their reproductive strategies
Authors: Fontaine J. J. , Martin T. E. 
Published: February 2006

AbstractAvian life history theory has long assumed that nest predation plays a minor role in shaping reproductive strategies. Yet, this assumption remains conspicuously untested by broad experiments that alter environmental risk of nest predation, despite the fact that nest predation is a major source of reproductive failure. Here, we examined whether parents can assess experimentally reduced nest predation risk and alter their reproductive strategies. We experimentally reduced nest predation risk and show that in safer environments parents increased investment in young through increased egg size, clutch mass, and the rate they fed nestlings. Parents also increased investment in female condition by increasing the rates that males fed incubating females at the nest, and decreasing the time that females spent incubating. These results demonstrate that birds can assess nest predation risk at large and that nest predation plays a key role in the expression of avian reproductive strategies.
Contamination routes of Clostridium botulinum in the honey production environment
Authors: Nevas Mari , Lindström Miia , Hörman Ari , Keto‐Timonen Riikka , Korkeala Hannu 
Published: February 2006

SummaryFactors influencing Clostridium botulinum contamination in the honey production environment were evaluated in a 3‐year survey. A number of 1168 samples from 100 apiaries and related facilities were analysed for the presence of C. botulinum types A, B, E and F, using multiplex polymerase chain reaction targeted to botA, botB, botE and botF genes. Production methods and environmental factors were registered using a questionnaire and by personal observation. Clostridium botulinum was shown to be a common finding throughout the whole honey production chain, and the type most frequently detected was group I type B. In a pulsed‐field gel electrophoresis (PFGE) analysis of 202 group I type B isolates, only six different PFGE profiles were observed, of which two clearly distinct profiles predominated. This may indicate the existence of at least two different genetic lineages. The high prevalence of C. botulinum in soil and in samples associated with beeswax suggests the accumulation of soil‐derived botulinal spores in wax. Additionally, according to Spearman’s rank order correlation and multivariate analysis, production hygiene‐dependent factors have a significant influence on the contamination, and thus the number and frequency of C. botulinum spores in honey could possibly be diminished by increasing hygienic level in honey production.
The galactophilic lectin, LecA, contributes to biofilm development in Pseudomonas aeruginosa
Authors: Diggle Stephen P. , Stacey Rachael E. , Dodd Christine , Cámara Miguel , Williams Paul , Winzer Klaus 
Published: February 2006

SummaryLecA (PA‐IL) is a cytotoxic lectin and adhesin produced by Pseudomonas aeruginosa which binds hydrophobic galactosides with high specificity and affinity. By using a lecA–egfp translation fusion and immunoblot analysis of the biofilm extracellular matrix, we show that lecA is expressed in biofilm‐grown cells. In static biofilm assays on both polystyrene and stainless steel, biofilm depth and surface coverage was reduced by mutation of lecA and enhanced in the LecA‐overproducing strain PAO‐P47. Biofilm surface coverage by the parent strain, PAO‐P47 but not the lecA mutant on steel coupons was also inhibited by growth in the presence of either isopropyl‐β‐D‐thiogalactoside (IPTG) or p‐nitrophenyl‐α‐D‐galactoside (NPG). Furthermore, mature wild‐type biofilms formed in the absence of these hydrophobic galactosides could be dispersed by the addition of IPTG. In contrast, addition of p‐nitrophenyl‐α‐L‐fucose (NPF) which has a high affinity for the P. aeruginosa LecB (PA‐IIL) lectin had no effect on biofilm formation or dispersal. Planktonic growth of P. aeruginosa PAO1 was unaffected by the presence of IPTG, NPG or NPF, nor was the strain able to utilize these sugars as carbon sources, suggesting that the observed effects on biofilm formation were due to the competitive inhibition of LecA–ligand binding. Similar results were also obtained for biofilms grown under dynamic flow conditions on steel coupons, suggesting that LecA contributes to P. aeruginosa biofilm architecture under different environmental conditions.
Amoebae promote persistence of epidemic strains of MRSA
Authors: Huws Sharon A. , Smith Anthony W. , Enright Mark C. , Wood Pauline J. , Brown Michael R. W. 
Published: February 2006

SummaryThe control of healthcare‐associated methicillin‐resistant Staphylococcus aureus (MRSA) infection is of concern worldwide. Given the evidence that several pathogenic species replicate within amoebae and emerge more virulent and more resistant and the abundance of amoebae in healthcare settings, we investigated interactions of Acanthamoeba polyphaga with epidemic MRSA isolates. MRSA proliferated in the presence of amoebae, attributable partly to intracellular replication. Following 24 h of co‐culture, confocal microscopy revealed that c. 50% amoebae had viable MRSA within phago‐lysosomes and 2% of amoebae were heavily infected with viable cocci throughout the cytoplasm. Infection control strategies should recognize the contribution of protozoa.
Bacterial diversity is determined by volume in membrane bioreactors
Authors: Van Der Gast Christopher J. , Jefferson Bruce , Reid Elizabeth , Robinson Tim , Bailey Mark J. , Judd Simon J. , Thompson Ian P. 
Published: February 2006

SummaryIt has been proposed that established models and theories developed in classical ecology could be employed to greatly improve the optimization of wastewater treatment plants (WWTP) by placing the microbiological component onto a model‐predictive basis. In particular, this could be achieved by better understanding bacterial community assembly and development. The species–area relationship is one of the oldest biological laws and has been used to describe spatial diversity patterns in contiguous habitats and on islands. In the current study, bacterial communities in seven membrane bioreactors (MBR), of increasing size, located across the UK were sampled. A significant linear relationship between bacterial taxa richness and reactor size was observed and was similar to classical species–area relationships of larger organisms colonizing oceanic islands. Rank‐abundance plots revealed a gradient of greater evenness in community structure as MBR volume increased. Application of the Raup and Crick probability‐based similarity index indicated a strong role for dispersal in MBR colonization and community structure. Our findings demonstrate that the MBR sampled behaved like islands with respect to bacterial colonization in accordance with the theory of island biogeography. In addition this study provides further evidence that biodiversity at the bacterial level is more similar to that of animals and plants than previously postulated.
Genetic variability in environmental isolates of Legionella pneumophila from Comunidad Valenciana (Spain)
Authors: Coscollá Mireia , Gosalbes María José , Catalán Vicente , González‐Candelas Fernando 
Published: February 2006

Summary Legionella pneumophila is associated to recurrent outbreaks in several Comunidad Valenciana (Spain) localities, especially in Alcoi, where social and climatic conditions seem to provide an excellent environment for bacterial growth. We have analysed the nucleotide sequences of three loci from 25 environmental isolates from Alcoi and nearby locations sampled over 3 years. The analysis of these isolates has revealed a substantial level of genetic variation, with consistent patterns of variability across loci, and comparable to that found in a large, European‐wide sampling of clinical isolates. Among the tree loci studied, fliC showed the highest level of nucleotide diversity. The analysis of isolates sampled in different years revealed a clear differentiation, with samples from 2001 being significantly distinct from those obtained in 2002 and 2003. Furthermore, although linkage disequilibrium measures indicate a clonal nature for population structure in this sample, the presence of some recombination events cannot be ruled out.