Observational study of the relationship between nurse staffing levels and compliance with mandatory nutritional assessments in hospital.

BACKGROUND: In the UK, it is recommended that hospital patients have their nutritional status assessed within 24 h of admission using the Malnutrition Universal Screening Tool (MUST). The present study aimed to examine the association between nurse staffing levels and missed nutritional status assessments. METHODS: A single-centre, retrospective, observational study was employed using routinely collected MUST assessments from 32 general adult hospital wards over 2 years, matched to ward nurse staffing levels. We used mixed-effects logistic regression to control for ward characteristics and patient factors. RESULTS: Of 43 451 instances where staffing levels could be linked to a patient for whom an assessment was due, 21.4% had no MUST score recorded within 24 h of admission. Missed assessments varied between wards (8-100%). There was no overall association between registered nurse staffing levels and missed assessments; although higher admissions per registered nurse were associated with more missed assessments [odds ratio (OR) = 1.09, P = 0.005]. Higher healthcare assistant staffing was associated with lower rates of missed assessments (OR = 0.80, P < 0.001). There was a significant interaction between registered nurses and healthcare assistants staffing levels (OR = 0.97, P = 0.011). CONCLUSIONS: Despite a written hospital policy requiring a nutritional assessment within 24 h of admission, missed assessments were common. The observed results show that compliance with the policy for routine MUST assessments within 24 h of hospital admission is sensitive to staffing levels and workload. This has implications for planning nurse staffing.

Heap leach cyanide irrigation and risk to wildlife: Ramifications for the international cyanide management code.

Exposed cyanide-bearing solutions associated with gold and silver recovery processes in the mining industry pose a risk to wildlife that interact with these solutions. This has been documented with cyanide-bearing tailings storage facilities, however risks associated with heap leach facilities are poorly documented, monitored and audited. Gold and silver leaching heap leach facilities use cyanide, pH-stabilised, at concentrations deemed toxic to wildlife. Their design and management are known to result in exposed cyanide-bearing solutions that are accessible to and present a risk to wildlife. Monitoring of the presence of exposed solutions, wildlife interaction, interpretation of risks and associated wildlife deaths are poorly documented. This paper provides a list of critical monitoring criteria and attempts to predict wildlife guilds most at risk. Understanding the significance of risks to wildlife from exposed cyanide solutions is complex, involving seasonality, relative position of ponding, temporal nature of ponding, solution palatability, environmental conditions, in situ wildlife species inventory and provision of alternative drinking sources for wildlife. Although a number of heap leach operations are certified as complaint with the International Cyanide Management Code (Cyanide Code), these criteria are not considered by auditors nor has systematic monitoring regime data been published. Without systematic monitoring and further knowledge, wildlife deaths on heap leach facilities are likely to remain largely unrecorded. This has ramifications for those operations certified as compliance with the Cyanide Code.

Comparison of the National Early Warning Score in non-elective medical and surgical patients.

BACKGROUND: The National Early Warning Score (NEWS) is used to identify deteriorating patients in hospital. NEWS is a better discriminator of outcomes than other early warning scores in acute medical admissions, but it has not been evaluated in a surgical population. The study aims were to evaluate the ability of NEWS to discriminate cardiac arrest, death and unanticipated ICU admission in patients admitted to surgical specialties, and to compare the performance of NEWS in admissions to medical and surgical specialties. METHODS: Hospitalwide data over 31 months, from adult inpatients who stayed at least one night or died on the day of admission, were analysed. The data were categorized as elective or non-elective surgical or medical admissions. The ability of NEWS to discriminate the outcomes above in these different groups was assessed using the area under the receiver operating characteristic curve (AUROC). RESULTS: There were too few outcomes to permit meaningful comparison of elective admissions, so the analysis was constrained to comparison of non-elective admissions. NEWS performed equally well, or better, for surgical as for medical patients. For death within 24 h the AUROC for surgical admissions was 0·914 (95 per cent c.i. 0·907 to 0·922), compared with 0·902 (0·898 to 0·905) for medical admissions. For the combined outcome of any of death, cardiac arrest or unanticipated ICU admission, the AUROC was 0·874 (0·868 to 0·880) for surgical admissions and 0·874 (0·871 to 0·877) for medical admissions. CONCLUSION: NEWS discriminated deterioration in non-elective surgical patients at least as well as in non-elective medical patients.

Procedure for measuring simultaneously the solar and visible properties of glazing with complex internal or external structures.

Accurate solar and visual transmittances of materials in which surfaces or internal structures are complex are often not easily amenable to standard procedures with laboratory-based spectrophotometers and integrating spheres. Localized "hot spots" of intensity are common in such materials, so data on small samples is unreliable. A novel device and simple protocols have been developed and undergone validation testing. Simultaneous solar and visible transmittance and reflectance data have been acquired for skylight components and multilayer polycarbonate roof panels. The pyranometer and lux sensor setups also directly yield "light coolness" in lumens/watt. Sample areas must be large, and, although mainly in sheet form, some testing has been done on curved panels. The instrument, its operation, and the simple calculations used are described. Results on a subset of diffuse and partially diffuse materials with no hot spots have been cross checked using 150 mm integrating spheres with a spectrophotometer and the Air Mass 1.5 spectrum. Indications are that results are as good or better than with such spheres for transmittance, but reflectance techniques need refinement for some sample types.

A national survey of obstetric early warning systems in the United Kingdom: five years on.

The Confidential Enquiries into Maternal Deaths in the UK have recommended obstetric early warning systems for early identification of clinical deterioration to reduce maternal morbidity and mortality. This survey explored early warning systems currently used by maternity units in the UK. An electronic questionnaire was sent to all 205 lead obstetric anaesthetists under the auspices of the Obstetric Anaesthetists' Association, generating 130 (63%) responses. All respondents reported use of an obstetric early warning system, compared with 19% in a similar survey in 2007. Respondents agreed that the six most important physiological parameters to record were respiratory rate, heart rate, temperature, systolic and diastolic blood pressure and oxygen saturation. One hundred and eighteen (91%) lead anaesthetists agreed that early warning systems helped to prevent obstetric morbidity. Staffing pressures were perceived as the greatest barrier to their use, and improved audit, education and training for healthcare professionals were identified as priority areas.

Radiative heat pumping from the Earth using surface phonon resonant nanoparticles.

Nanoparticles that have narrow absorption bands that lie entirely within the atmosphere's transparent window from 7.9 to 13 mum can be used to radiatively cool to temperatures that are well below ambient. Heating from incoming atmospheric radiation in the remainder of the Planck radiation spectrum, where the atmosphere is nearly "black", is reduced if the particles are dopants in infrared transmitting polymers, or in transmitting coatings on low emittance substrates. Crystalline SiC nanoparticles stand out with a surface phonon resonance from 10.5 to 13 mum clear of the atmospheric ozone band. Resonant SiO(2) nanoparticles are complementary, absorbing from 8 to 10 mum, which includes atmospheric ozone emissions. Their spectral location has made SiC nanoparticles in space dust a feature in ground-based IR astronomy. Optical properties are presented and subambient cooling performance analyzed for doped polyethylene on aluminum. A mixture of SiC and SiO(2) nanoparticles yields high performance cooling at low cost within a practical cooling rig.

Metal-in-metal localized surface plasmon resonance.

Anomalous strong resonances in silver and gold nanoporous thin films which conduct are found to arise from isolated metal nano-islands separated from the surrounding percolating metal network by a thin loop of insulator. This observed resonant optical response is modelled. The observed peak position is in agreement with the observed average dimensions of the silver core and insulator shell. As the insulating ring thickness shrinks, the resonance moves to longer wavelengths and strengthens. This structure is the Babinet's principle counterpart of dielectric core-metal shell nanoparticles embedded in dielectric. Like for the latter, tuning of resonant absorption is possible, but here the matrix reflects rather than transmits, and tuning to longer wavelengths is more practical. A new class of metal mirror occurring as a single thin layer is identified using the same resonances in dense metal mirrors. Narrow band deep localized dips in reflectance result.

Vital signs and other observations used to detect deterioration in pregnant women: an analysis of vital sign charts in consultant-led UK maternity units.

BACKGROUND: Obstetric early warning systems are recommended for monitoring hospitalised pregnant and postnatal women. We decided to compare: (i) vital sign values used to define physiological normality; (ii) symptoms and signs used to escalate care; (iii) type of chart used; and (iv) presence of explicit instructions for escalating care. METHODS: One-hundred-and-twenty obstetric early warning charts and escalation protocols were obtained from consultant-led maternity units in the UK and Channel Islands. These data were extracted: values used to determine normality for each maternal vital sign; chart colour-coding; instructions following early warning system triggering; other criteria used as triggers. RESULTS: There was considerable variation in the charts, warning systems and escalation protocols. Of 120 charts, 89.2% used colour; 69.2% used colour-coded escalation systems. Forty-one (34.2%) systems required the calculation of weighted scores. Seventy-five discrete combinations of 'normal' vital sign ranges were found, the most common being: heart rate=50-99beats/min; respiratory rate=11-20breaths/min; blood pressure, systolic=100-149mmHg, diastolic ≤89mmHg; SpO2=95-100%; temperature=36.0-37.9°C; and Alert-Voice-Pain-Unresponsive assessment=Alert. Most charts (90.8%) provided instructions about who to contact following triggering, but only 41.7% gave instructions about subsequent observation frequency. CONCLUSION: The wide range of 'normal' vital sign values in different systems suggests a lack of equity in the processes for detecting deterioration and escalating care in hospitalised pregnant and postnatal women. Agreement regarding 'normal' vital sign ranges is urgently required and would assist the development of a standardised obstetric early warning system and chart.

Functional domains of GABAA receptors.

The transmitter-gated ion channels mediate rapid synaptic transmission, for example, at the neuromuscular junction using acetylcholine and in the CNS using primarily the amino acids glutamate and GABA. GABAA-receptor Cl- channels share sequence homology with a superfamily of these channels including nicotinic acetylcholine receptor and inhibitory glycine receptor. In this article, Geoffrey Smith and Richard Olsen discuss recent affinity labelling and site-directed mutagenesis studies on GABAA receptors that have identified amino acid residues essential for binding of agonists and allosteric modulators as well as the ion channel wall formation. The structural domains identified are consistent with results obtained with other members of the transmitter-gated ion channel superfamily and suggest that structural models for one member of the family may apply to the others as well.

The use of routine laboratory data to predict in-hospital death in medical admissions.

The ability to predict clinical outcomes in the early phase of a patient's hospital admission could facilitate the optimal use of resources, might allow focused surveillance of high-risk patients and might permit early therapy. We investigated the hypothesis that the risk of in-hospital death of general medical patients can be modelled using a small number of commonly used laboratory and administrative items available within the first few hours of hospital admission. Matched administrative and laboratory data from 9497 adult hospital discharges, with a hospital discharge specialty of general medicine, were divided into two subsets. The dataset was split into a single development set, Q(1) (n=2257), and three validation sets, Q(2), Q(3) and Q(4) (n(1)=2335, n(2)=2361, n(3)=2544). Hospital outcome (survival/non-survival) was obtained for all discharges. An outcome model was constructed from binary logistic regression of the development set data. The goodness-of-fit of the model for the validation sets was tested using receiver-operating characteristics curves (c-index) and Hosmer-Lemeshow statistics. Application of the model to the validation sets produced c-indices of 0.779 (Q(2)), 0.764 (Q(3)) and 0.757 (Q(4)), respectively, indicating good discrimination. Hosmer-Lemeshow analysis gave chi(2)=9.43 (Q(2)), chi(2)=7.39 (Q(3)) and chi(2)=8.00 (Q(4)) (p-values of 0.307, 0.495 and 0.433) for 8 degrees of freedom, indicating good calibration. The finding that the risk of hospital death can be predicted with routinely available data very early on after hospital admission has several potential uses. It raises the possibility that the surveillance and treatment of patients might be categorised by risk assessment means. Such a system might also be used to assess clinical performance, to evaluate the benefits of introducing acute care interventions or to investigate differences between acute care systems.

'Errors' and omissions in paper-based early warning scores: the association with changes in vital signs--a database analysis.

OBJECTIVES: To understand factors associated with errors using an established paper-based early warning score (EWS) system. We investigated the types of error, where they are most likely to occur, and whether 'errors' can predict subsequent changes in patient vital signs. METHODS: Retrospective analysis of prospectively collected early warning system database from a single large UK teaching hospital. RESULTS: 16,795 observation sets, from 200 postsurgical patients, were collected. Incomplete observation sets were more likely to contain observations which should have led to an alert than complete observation sets (15.1% vs 7.6%, p<0.001), but less likely to have an alerting score correctly calculated (38.8% vs 30.0%, p<0.001). Mis-scoring was much more common when leaving a sequence of three or more consecutive observation sets with aggregate scores of 0 (55.3%) than within the sequence (3.0%, p<0.001). Observation sets that 'incorrectly' alerted were more frequently followed by a correctly alerting observation set than error-free non-alerting observation sets (14.7% vs 4.2%, p<0.001). Observation sets that 'incorrectly' did not alert were more frequently followed by an observation set that did not alert than error-free alerting observation sets (73.2% vs 45.8%, p<0.001). CONCLUSIONS: Missed alerts are particularly common in incomplete observation sets and when a patient first becomes unstable. Observation sets that 'incorrectly' alert or 'incorrectly' do not alert are highly predictive of the next observation set, suggesting that clinical staff detect both deterioration and improvement in advance of the EWS system by using information not currently encoded within it. Work is urgently needed to understand how best to capture this information.

Studies on the transfer of steroid hormones across the blood-cerebrospinal fluid barrier in the rhesus monkey. II.

The movement of progesterone (P), cortisol (F) and 17-hydroxyprogesterone (17-OHP) across the blood-cerebrospinal fluid (CSF) barrier was determined using six adult male rhesus monkeys with indwelling canulae in the lateral ventricles of their brains. Tritiated steroids were given iv as a bolus followed by a constant 6 h infusion with continuous collection of CSF and periodic sampling of blood before and during the infusion. The amounts of authentic steroid in the plasma and CSF were determined by recrystallization to constant isotopic ratio and the amount of free plasma steroid was determined by equilibrium dialysis against Ringer's solution. Tritiated progesterone was undetectable in the pooled samples of CSF. The average concentration of tritiated 17-OHP in the CSF was 10.3% of the concurrent plasma level while the concentration of tritiated F was 22.5% of the concurrent plasma level. Plasma free steroid was found to be 2.2% for P, 6.3% for 17-OHP and 22.3% for F, showing a rough correlation between steroid entry into the CSF and free steroid concentration in plasma.

Human lung microsomal cytochrome P4501A1 (CYP1A1) activities: impact of smoking status and CYP1A1, aryl hydrocarbon receptor, and glutathione S-transferase M1 genetic polymorphisms.

There are numerous conflicting epidemiological studies addressing correlations between cytochrome P450 1A1 (CYP1A1) genetic polymorphisms and lung cancer susceptibility, with associations plausibly linked to alterations in carcinogen bioactivation. Similarly, correlations between aryl hydrocarbon receptor gene (AHR) codon 554 genotype and CYP1A1 inducibility are controversial. The objective of this study was to determine whether smoking status, and CYP1A1, AHR, and glutathione S-transferase M1 gene (GSTM1) polymorphisms correlate with altered CYP1A1 activities. Lung microsomal CYP1A1-catalyzed 7-ethoxyresorufin O-dealkylation (EROD) activities were much higher in tissues from current smokers (n = 46) than in those from non-/former smokers (n = 24; 12.11 +/- 13.46 and 0.77 +/- 1.74 pmol/min/mg protein, respectively, mean +/- SD; P < 0.05). However, EROD activities in lung microsomes from current smokers CYP1A1*1/1 (n = 33) and heterozygous MspI variant CYP1A1*1/2A (n = 10) were not significantly different (12.23 +/- 13.48 and 8.23 +/- 9.76 pmol/min/mg protein, respectively, P > 0.05). Three current smokers were heterozygous variant CYP1A1*1/2B (possessing both *2A and *2C alleles), and exhibited activities similar to individuals CYP1A*1/1. One current smoker was heterozygous variant CYP1A1*4 and exhibited activities comparable with individuals CYP1A1*1/1 at that locus. EROD activities in microsomes from current smokers AHR(554)Arg/Arg (n = 41) and heterozygous variant AHR(554)Arg/Lys (n = 5) were not significantly different (12.13 +/- 13.56 and 12.01 +/- 14.23 pmol/min/mg protein, respectively; P > 0.05). Furthermore, microsomal EROD activities from current smokers with the GSTM1-null genotype (n = 28) were not significantly different from those (n = 18) carrying at least one copy of GSTM1 (12.61 +/- 14.24 and 11.34 +/- 12.53 pmol/min/mg protein, respectively; P > 0.05). Additionally, when genotypic combinations of CYP1A1, AHR, and GSTM1 were assessed, there were no significant effects on EROD activity. On the basis of microsomal enzyme activities from heterozygotes, CYP1A1*1/2A, CYP1A1*1/2B, CYP1A1*1/4, and AHR(554) Arg/Lys variants do not appear to significantly affect CYP1A1 activities in human lung, and we observed no association between CYP1A1 activity and the GSTM1-null polymorphism.

Deduction of amino acid residues in the GABA(A) receptor alpha subunits photoaffinity labeled with the benzodiazepine flunitrazepam.

Peptide mapping and microsequencing were used to infer the site of photoaffinity labeling by the gamma-aminobutyric acidA receptor modulator [3H]flunitrazepam. Peptide mapping with and without N-deglycosylation was used to restrict the domain for photoaffinity labeling to residues 74-123 of the bovine alpha1 subunit, in agreement with a previously predicted labeling domain between residues 59-148 based on cyanogen bromide fragmentation. Edman degradation of partially purified photolabeled peptides gave release of 3H counts in the ninth cycle of a tryptic peptide sequence. A second V8/chymotryptic peptide produced an impure sequence with release of 3H counts in the seventh through ninth cycle of sequence. The combined data support those previously reported, i.e., that the primary site for photoaffinity labeling by [3H]flunitrazepam is His102 of the bovine alpha1 subunit. In addition we also detected possible secondary labeling of Pro97.

Factors associated with surfactant treatment response in infants with severe respiratory distress syndrome.

In a prospective, randomized study of 18 infants treated with bovine surfactant (surfactant TA, Tokyo Tanabe Co, Tokyo) for severe respiratory distress syndrome, a lasting response was found in 12 infants (66%), a transient response was found in two (11%), and no response was found in four (22%) when arterial to alveolar PO2 ratios were used to define responses during the first 48 hours after treatment. In contrast, three of 23 control infants (13%) had a transient or lasting "response" to sham treatment (Pediatrics 1987;79:31-37). To determine whether maldistribution of surfactant could explain lack of response or a transient response, surfactant TA was mixed with technetium-99m sulfur colloid (approximately 300 mu Ci per infant), and eight infants with severe respiratory distress syndrome were treated six to 58 hours after birth. Scintigraphy of the lungs was performed three to 15 hours after treatment. Although a lasting response was observed in three infants, a transient one in three, and no response in two, no gross maldistribution of the radioactive label was found. Either lung received from 37% to 62% of the total radioactivity. During the past 3 years, in all infants with severe respiratory distress syndrome who were treated with surfactant (n = 29), poor or transient responses were associated with early patent ductus arteriosus and air leaks (pulmonary interstitial emphysema and pneumothoraces). Pathophysiologic conditions associated with respiratory distress syndrome are more likely to explain suboptimal responses after surfactant treatment than gross maldistribution of surfactant in the lungs.

Comparison of outcome from intensive care admission after adjustment for case mix by the APACHE III prognostic system.

STUDY OBJECTIVES: To evaluate the acute physiology, age, chronic health evaluation III (APACHE III) scoring system in the context of general adult ICUs in the United Kingdom. DESIGN: Prospective, noninterventional, cohort study. SETTING: Seventeen general adult ICUs in a discrete area of southwest England. PATIENTS: 12,793 patients admitted between April 1, 1993 and December 31, 1995. MEASUREMENTS: Sociodemographic and severity-of-illness data were collected for all patients admitted to the study units. Formal goodness-of-fit tests were applied and observed mortality was compared with that predicted by using the APACHE III system. RESULTS: For the group of ICUs as a whole, the risk-adjusted standardized mortality ratio (SMR) was 1.23 (95% confidence intervals, 1.12-1.25). For 11 out of 17 ICUs, the SMR was significantly greater than unity (p < 0.05). Calibration, as tested by Hosmer-Lemeshow statistics, was poor (H2 = 312.54; C2 = 332.85; df = 8; p < 0.01); however, model discrimination was good with a total correct classification rate of 82.9% and an area under the receiver operating characteristic curve of 0.89. CONCLUSIONS: The excess mortality observed after case-mix adjustment using the APACHE III system in this study may be the result of either poor intensive care performance as compared with the United States or a failure of the APACHE III equation to fit the UK data.