Detection of adverse events in a Scottish hospital using a consensus-based methodology

OBJECTIVE

To determine, using a consensus based methodology, the rate and nature of adverse events (AEs) among patients admitted to acute medicine, acute surgery and obstetrics in a large teaching hospital in Scotland.

METHODS

Retrospective case-note review of 450 medical, nursing and medication records to identify and classify adverse events. For 354 patients whose length of stay was greater than 24 hours, the overall adverse event rate was 7.9% which ranged from 0% in obstetrics, 7.2% in acute medicine to 13% in acute surgery. Among all AEs, 43% were deemed preventable by a consensus group and 59% of the AEs contributed to a proportion of the patients' hospital stay or led to hospital readmission. Whilst nurse identification of adverse events was highly specific (94%), its sensitivity was poor (43%). Only 10% of the identified AEs were identified by the hospital's voluntary reporting system for adverse events. The estimated additional cost of adverse events in terms of bed days was ł69,189 which if extrapolated Scotland-wide could cost ł297 million per annum.

CONCLUSIONS

This study supports the need to continue the traditional retrospective record review to identify adverse events. The current hospital-based reporting of adverse events does not provide a complete measure of adverse events and needs to be complemented by other measures.

Statistical modeling of spatial distortion in hyperspectral calibration

This paper describes a statistically based efficient algorithm for the laboratory spectral calibration of a low-resolution terrestrial hyperspectral imaging camera operating in the visible range. Didymium oxide is used as a wavelength standard. The observed periodic spatial distortion in the wavelength abscissa of the hypercube is removed automatically through statistical modeling and the calibration of the wavelength abscissa is determined using a numerical method. The performance and cost of this algorithm in removing the spatial distortion are assessed quantitatively.

Ferritin: a novel mechanism for delivery of iron to the brain and other organs

Traditionally, transferrin has been considered the primary mechanism for cellular iron delivery, despite suggestive evidence for additional iron delivery mechanisms. In this study we examined ferritin, considered an iron storage protein, as a possible delivery protein. Ferritin consists of H- and L-subunits, and we demonstrated iron uptake by ferritin into multiple organs and that the uptake of iron is greater when the iron is delivered via H-ferritin compared with L-ferritin. The delivery of iron via H-ferritin but not L-ferritin was significantly decreased in mice with compromised iron storage compared with control, indicating that a feedback mechanism exists for H-ferritin iron delivery. To further evaluate the mechanism of ferritin iron delivery into the brain, we used a cell culture model of the blood-brain barrier to demonstrate that ferritin is transported across endothelial cells. There are receptors that prefer H-ferritin on the endothelial cells in culture and on rat brain microvasculature. These studies identify H-ferritin as an iron transport protein and suggest the presence of an H-ferritin receptor for mediating iron delivery. The relative amount of iron that could be delivered via H-ferritin could make this protein a predominant player in cellular iron delivery.

Tissue engineering of vascular conduits

BACKGROUND

Autologous conduits are not available in up to 40 per cent of patients with arteriopathy who require coronary or lower limb revascularization, and access sites for renal dialysis may eventually become exhausted. Synthetic prostheses achieve a poor patency rate in small-calibre anastomoses. This review examines how vascular tissue engineering may be used to address these issues.

METHODS

A Medline search was performed, using the keywords "vascular tissue engineering", "small diameter vascular conduit", "vascular cell biology", "biomechanics", "cell seeding" and "graft endothelialization". Key references were hand-searched for relevant papers.

RESULTS AND CONCLUSION

In vitro and in vivo approaches are currently being used for guided cell repopulation of both biological and synthetic scaffolds. The major clinical problem has been extended culture time (approximately 6 weeks), which precludes their use in the acute setting. However, recent advances have led not only to improved patency rates for prostheses, but also to a potential reduction in culture time. In addition, increased mobilization of endothelial progenitor cells in the presence of ischaemic tissue may increase the autologous cell yield for scaffold reseeding with further reduction in culture time.

Incremental shuttle walking is associated with activation of haemostatic and haemorheological markers in patients with coronary artery disease: the Birmingham rehabilitation uptake maximization study (BRUM)

OBJECTIVE

To test the hypothesis that an incremental shuttle walk test (ISWT) affects plasma indices of endothelial damage and dysfunction (von Willebrand factor (vWf)), platelet activation (soluble P-selectin), thrombogenesis (D-dimer), fibrinogen, and plasma viscosity more adversely in coronary artery disease (CAD) than in health. ISWT is a standardised walking test that provokes maximal performance and correlates strongly with maximum oxygen uptake.

METHODS

Research indices were measured before a practice ISWT and immediately after the second ISWT in 53 patients with CAD (48 men, mean (SD) age 59 (10) years) and in 19 matched healthy controls (16 men, 61 (10) years). Data were analysed before and after ISWT.

RESULTS

Despite no significant difference in total distance walked between patients and controls, vWf (162 (45) before v 170 (48) UI/dl after) and fibrinogen (2.9 (0.7) v 3.1 (0.7) g/l) concentrations, plasma viscosity (1.63 (0.12) v 1.71 (0.14) mPa.s), and D-dimer (0.20 (interquartile range 0.10-0.30) v 0.21 (0.12-0.31 mg/l; all p < 0.05), but not soluble P-selectin, were significantly increased after ISWT in patients with CAD, even after correction for plasma volume change. Only fibrinogen (2.5 (0.7) v 2.7 (0.7 g/l) and plasma viscosity (1.60 (0.08) v 1.64 (0.08) mPa.s; both p < 0.01) increased among controls. The increment of fibrinogen was significantly higher in patients than in controls (p = 0.035) and correlated with total walking distance (r = 0.46, p < 0.001) and peak heart rate (r = 0.28, p = 0.02). The increment of plasma viscosity rise also significantly correlated with total distance walked (r = 0.66, p < 0.001).

CONCLUSIONS

ISWT in patients with CAD appears to increase fibrinogen, vWf, and D-dimer compared with healthy controls.

Mutations in the gene for toll-like receptor 4 and multiple sclerosis

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system with heterogeneous pathological features, disease courses and genetical backgrounds. In this study we determined whether genetic variants of toll-like receptor (TLR) 4, which confer substantial differences in the inflammation elicited by bacterial lipopolysaccharide, are related to the development of MS. We found no differences in the frequencies of the cosegregating TLR4 Asp299Gly and Thr399Ile polymorphisms between Austrian MS patients (11.6%) and age-matched controls (13.7%). Furthermore, we could not detect any influence of these mutations on clinical parameters and serum levels of soluble adhesion molecules of MS patients. Our data indicate that these TLR4 polymorphisms have no influence on the incidence, progression and inflammatory parameters of MS.

An improved staining method for intervertebral disc tissue

The objective of this study was to design a new staining procedure for human disc tissue for visualizing both collagen and proteoglycan-matrix components on the same histology section. Weigert's hematoxylin, alcian blue and picrosirius red were combined to produce distinctive staining of collagen (red), proteoglycans (blue) and cellular elements of the intervertebral disc. This novel stain reveals sharp details of collagen composition in the perilacunar, territorial and intraterritorial extracellular matrix, and concomitantly demonstrates the presence of proteoglycan accumulations around cells in the lacunar spaces and in the extracellular matrix. These details reveal variations within the tissue that would not be apparent with routine stains.

Breastfeeding: it is worth trying with the second baby

Mothers who experience breastfeeding difficulties with their first babies and give up breastfeeding are less likely to breastfeed subsequent babies than mothers who do not experience such difficulties. We carried out a longitudinal study of 22 mothers in which milk output was measured at 1 week and 4 weeks after giving birth to their first and second babies. Significantly more breast milk was produced at 1 week for the second lactation (an increase of 31% [95% CI 11-51%]) and the net increase was greatest for those with the lowest milk output on the first occasion (90% [30-149%]). They spent less time feeding their second baby (a decrease of 20% [-34 to -5%]). This increased efficiency of milk transfer was also evident at 4 weeks. Health professionals should encourage women to breastfeed all their children, whatever their experience with their first child.

Morphologic and molecular evidence for gap junctions and connexin 43 and 45 expression in annulus fibrosus cells from the human intervertebral disc

Data are presented which provide evidence for gap junction formation and connexin (Cx) 43 and 45 gene expression in human intervertebral disc cells in vivo and in vitro. These findings in cells from the annulus are important in conjunction with the well-recognized loss of disc cells during aging and disc degeneration. As a result of this loss of cells, cell-cell communication, which we propose is an important, but as yet poorly understood, mechanism which links and coordinates cellular function throughout the entire population of disc cells, is also disrupted. These studies provide additional information on the fundamental cell biology of the disc cell and provide an additional framework for understanding aging, degeneration and potential repair of the human disc.

Cannulation of the distal ileum in ponies

A simple "T" cannula was placed in the distal ileum of nine mature pony geldings. With the animal under general anesthesia, the plastisol (polyvinyl chloride) cannula was placed in the distal ileum, and exteriorized caudal to the 16th rib. The cannula surgery was simple and recovery was rapid, resulting in ponies that could be used in nutritional studies within 1 mo of surgery. With regular maintenance cannulated ponies can remain viable for periods of time greater than 1 yr. Key words: Equine, distal ileum, small intestine, cannulation simple "T" cannula

Analysis of cDNA clones encoding sucrose-phosphate synthase in relation to sugar interconversions associated with dehydration in the resurrection plant Craterostigma plantagineum Hochst

Sucrose-phosphate synthase (SPS) is a key enzyme in the regulation of sucrose metabolism, being responsible for the synthesis of sucrose 6-phosphate from fructose 6-phosphate and uridine 5'-diphosphate-glucose. We report on the isolation and characterization of cDNA clones encoding SPS from Craterostigma plantagineum Hochst., a resurrection plant in which the accumulation of sucrose is considered to play an important role in tolerance to severe protoplastic dehydration. Two distinct classes of cDNAs encoding SPS were isolated from C. plantagineum, and are represented by the clones Cpsps1 and Cpsps2. The transcripts corresponding to both cDNAs decrease to very low levels in dehydrating leaves of C. plantagineum. Only the Cpsps1 transcript occurs in the roots, where it is present at a higher level than in leaves and increases upon dehydration of the plant. Higher enzymatic activities have been determined in protein extracts of dehydrated tissues compared with untreated tissues, which correlates with an increase in protein levels. It is suggested that the overall regulation of SPS is strongly influenced by the changing composition of the cytoplasm in C. plantagineum leaves during the dehydration-rehydration cycle.

Central venous access devices in children with hemophilia: an update

The most frequent indication for placement of a central venous access device in hemophiliacs is in very young boys (ages 1-2 years) with severe hemophilia who are started on a program of long-term factor prophylaxis designed to eliminate target joint bleeding and the development of chronic musculoskeletal disease. Although expensive, this strategy is extremely successful. It involves intravenous infusion of 25-40 factor units per kg on alternate days (minimum 3 times a week) for boys with severe hemophilia A, and twice a week for boys with severe hemophilia B. To facilitate this prophylaxis regimen some hemophilia clinics routinely recommend placement of a central venous access device; others, more concerned about associated complications such as sepsis, stress the importance of using peripheral veins wherever possible, with central access devices reserved for occasional, selected cases only. A decision to use such a device should only be made after discussion of the risks/benefits with parents (or guardians) and with patients if of an appropriate age. If such a system is to be used, we recommend that a totally implantable device (Port-A-Cath) be placed because of the lower risk of infection, and because totally implantable devices allow children to take part in activities such as swimming. Important complications include catheter-related sepsis, which may occur in 25% or more of devices over time and, much less frequently, catheter-related deep vein thrombosis.

Nested PCR protocol for the rapid detection of Escherichia coli in potable water

A rapid and sensitive method for the detection of low levels of bacteria in potable water was developed. The fecal indicator bacterium Escherichia coli was used as the test organism in a filtration concentration - nested polymerase chain reaction (PCR) protocol, combined with ethidium bromide visualization of PCR products. Two sets of primers were designed from the E. coli specific beta-glucuronidase gene (uidA), the primary pair producing a 486-bp fragment that was used as template for the nested primer pair delineating a 186-bp fragment. This protocol can detect 1-10 bacterial cells/50 mL water sample within 6-8 h, in contrast to traditional culturing or Southern hybridization methods which require 2-3 days for results.

THE MOLECULAR BASIS OF DEHYDRATION TOLERANCE IN PLANTS

Molecular studies of drought stress in plants use a variety of strategies and include different species subjected to a wide range of water deficits. Initial research has by necessity been largely descriptive, and relevant genes have been identified either by reference to physiological evidence or by differential screening. A large number of genes with a potential role in drought tolerance have been described, and major themes in the molecular response have been established. Particular areas of importance are sugar metabolism and late-embryogenesis-abundant (LEA) proteins. Studies have begun to examine mechanisms that control the gene expression, and putative regulatory pathways have been established. Recent attempts to understand gene function have utilized transgenic plants. These efforts are of clear agronomic importance.

Central venous access catheters in children with haemophilia

Twenty-five central venous lines (two external 23 subcutaneous ports) were placed in 19 boys with haemophilia A (n = 17) or B (n = 2). The mean age of the boys was 4.9 years (range 0.2-15.3 years). The haemophilia was severe (factor level < 1%) in 18 boys and moderate (factor level 3%) in one. Three boys had circulating inhibitors and three were positive for human immunodeficiency virus (HIV)-1 antibody. Central venous lines were placed to facilitate intermittent factor replacement therapy (n = 6), long-term factor prophylaxis (n = 9), induction of an immune tolerance protocol (n = 2) or therapy for acquired immunodeficiency syndrome (AIDS)-related complications (n = 2). The ports remained in place for 15795 days (mean 687 days, range 11-2059 days). The frequency of port-related sepsis was 48% (11/23 ports in eight boys) or 0.7 port infections per 1000 patient days. Ports were removed from five boys with an unresolved infection (four with Staphylococcus aureus sepsis and one with Pseudomonas sp. sepsis). Other complications requiring port removal included a catheter tip placed too high in the venous system (n = 1), severe persistent pain associated with needle access of the port (n = 1) and a subclavian vein thrombosis (n = 1). Both the benefits and risks of a subcutaneous port should be considered when deciding whether to place this device in a very young child with haemophilia.

Peripherally inserted central catheters in children

PURPOSE

To assess the feasibility and complications of peripherally inserted central catheters (PICCs) in pediatric patients.

MATERIALS AND METHODS

The authors attempted to place PICCs in 122 patients aged 9 days to 19 years (mean, 6.82 years; median, 5 years). Catheters were placed to allow prolonged administration of antibiotics or chemotherapeutic agents (n = 50), provide total parenteral nutrition (n = 41), and establish prolonged intravenous access for blood draws and fluid administration (n = 31). Silicone catheters measuring 3, 4, and 5 F were inserted in either basilic or cephalic veins and positioned at the junction of the superior vena cava and right atrium under fluoroscopic guidance. Patients were monitored for complications until devices were removed.

RESULTS

Fluoroscopically guided PICC placement was successful in 137 of 148 attempts. Postinsertion complications included mechanical defects of the catheter, PICC-related infection, occlusion of the PICC, and venous stasis. Complications occurred at a rate comparable to those seen with blind insertion.

CONCLUSION

Fluoroscopically guided PICC placement is feasible and safe in pediatric patients.