The use of AEDs by police officers in the City of London. Automated external defibrillators

The Guidelines 2000 for cardiopulmonary resuscitation recommend shock delivery to victims in ventricular fibrillation within 5 min of call receipt by the Emergency Medical Services. In an effort to achieve this goal, in some parts of the United States, police officers have been trained to use automated external defibrillators (AEDs). We undertook a 3-year pilot evaluation of the use of AEDs by City of London police (CPOL) officers. Over a period of 3 years, 147 CPOL officers were trained in the use of an AED. Four AEDs were placed on rapid response vehicles covering the City of London. An overall call-response interval target was set at 8 min. The CPOL attended 1103 (90%) of the total of 1232 calls to which they were summoned. The mean interval between the first call received and arrival of the CPOL on scene was 8.9+/-4.0 min. The CPOL applied AEDs to 25 victims, 13 of whom were initially in ventricular fibrillation; at least one shock was delivered to all 13. The interval between call reception and delivery of the first shock was 5.5+/-2.5 min. The mean interval between switching on the AED and delivery of the first shock was 24+/-12 s. Two (15%) of these victims survived to hospital discharge. This study has confirmed the feasibility of training police officers in the UK to use AEDs as first responders. The call received to arrival on scene interval should be reduced by improvements in communication between LAS and CPOL.

Advanced life support skills undertaken by nurses--UK survey

Many nurses successfully complete the Resuscitation Council (UK), European Resuscitation Council, advanced life support (ALS) Provider Course. Acquiring ALS provider status is not necessarily a licence to practice and individual hospital policy determines which skills these nurses can then perform without direct medical supervision. This postal survey aimed to determine which ALS skills are utilised by nurse ALS providers working in a variety of clinical areas within acute hospitals in the UK. A questionnaire was sent to the Resuscitation Officer or Nursing Director of all acute hospital groups in the UK. Almost 261 (87%) of the questionnaires were completed and returned. Nurse ALS providers in 99% of coronary care units, 89% of intensive care units, and 88% of accident and emergency departments undertook manual defibrillation. The majority of hospitals ran compulsory in-house training sessions for intravenous cannulation. Laryngeal mask insertion by nurse ALS providers was permitted in 19% of coronary care units and in the wards of 16% of the responding hospitals. Tracheal intubation by nurse ALS providers working in coronary care units, intensive care units and emergency departments was permitted by 11% of the responding hospitals. This survey has demonstrated that many acute hospitals do not permit nurse ALS providers to use a number of the skills taught on the ALS provider course. General ward-based nurse ALS providers, in particular, are restricted in the ALS skills, they are permitted to use. It would be more efficient for nurses to be trained and assessed specifically in skills they are then permitted to use. Having been assessed in a given skill and achieved a nationally recognised standard, nurse ALS providers should be permitted to use it in clinical practice.

Improving the health of older people: what do we do?

This article, based on a paper given at the International Network for Studies Concerning Older Adults conference in Brazil, considers the health of older people. It argues that greater efforts must be made both to improve preventive healthcare interventions and enhance quality of life. It is suggested that nurses have a significant but, as yet, largely unrealized role to play and that action is needed if older people are to get maximum benefit from health care.

Detection of multivalent interactions through two-tiered energy transfer

A method based on two-tiered fluorescence resonant energy transfer (FRET) has been developed for selective and sensitive detection of species involved in a multivalent interaction. Pentavalent binding between cholera toxin and ganglioside GM1 is used as a model system to demonstrate the advantage of the two-tiered FRET over one-stage FRET in both conventional fluorimeter and flow cytometer. In the system, three fluorescent probes (namely, fluorescence donor, acceptor, and intermediate) are covalently tagged to receptors, and the intermediate is used to bridge the energy transfer between the donor and acceptor even though the donor's fluorescence spectrum does not overlap with absorption spectrum of the acceptor. One of the most significant improvements of the scheme over one-stage FRET is a dramatic decrease in the background fluorescence of the acceptor fluorescence, which, theoretically and practically, increases the detection sensitivity.

Developing the nurse's role in patient education: rehabilitation as a case example

Over the past decade considerable emphasis has been placed on the nurse's role in patient education. Despite this numerous studies have suggested that this aspect of nursing practice is under-developed. Using rehabilitation as a case example this paper explores the nursing contribution to patient education in five conditions: multiple sclerosis; arthritis; myocardial infarction; spinal injury and stroke. Although the literature identifies considerable potential for nurses to take a lead role in patient education this is rarely achieved in practice. Analyses of printed curricula from a range of courses indicate that nurses are not adequately prepared for patient education and that a reorientation of nurse education is required.

Review of management of purpura fulminans and two case reports

Purpura fulminans (PF) is a haemorrhagic condition usually associated with sepsis or previous infection. Features include tissue necrosis, small vessel thrombosis and disseminated intravascular coagulation. Gram-negative organisms are the commonest cause of the acute infectious type, which is often associated with multi-organ failure. An idiopathic variety, however, is often confined to the skin. The mortality rate has decreased with better treatment of secondary infections, supportive care and new treatments, but it remains a disabling condition often requiring major amputations. We describe two cases and review the various treatments for this condition.

European Resuscitation Council Guidelines 2000 for Adult Advanced Life Support. A statement from the Advanced Life Support Working Group(1) and approved by the Executive Committee of the European Resuscitation Council

The European Resuscitation Council (ERC) last issued guidelines for Basic Life Support (BLS) in 1998 [1]. These were based on the 1997 International Liaison Committee on Resuscitation (ILCOR) Advisory Statements [2]. In 1999 and 2000 representatives of ILCOR, at the invitation of the American Heart Association, met on a number of occasions in Dallas to agree a Consensus on Science upon which future guidelines would be based. Representatives from the ERC played a prominent role in the deliberations, which culminated in the publication of "Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care--A Consensus on Science" in August 2000 [3]. The consensus was evidence-based wherever possible. The ERC ALS Working Group has considered this document and has recommended some changes in the guidelines that will be suitable for European practice. These changes, together with a summary of the Sequence of Actions in ALS, are presented in this paper.

The Key Extended Entry Program (KEEP): a methadone treatment program for opiate-dependent inmates

The Key Extended Entry Program (KEEP) is the only known methadone treatment program for incarcerated opiate-dependent inmates in the United States. Initiated in 1987, KEEP performs approximately 18,000 detoxifications and 4,000 admissions for methadone treatment per year. Of those methadone treatment patients discharged to the community, mostly to outpatient KEEP programs, 74-80% report to their designated program. Recidivism rates reveal that 79% of KEEP patients were incarcerated again only once or twice during a recent 11-year period. Finally, KEEP data point to the importance of dedicating slots in the community for released inmates and maintaining them on sufficient blocking doses to eliminate the craving for heroin. About 6% of KEEP patients, some with mental illness have a high incidence of recidivism.

Fluid resuscitation for the trauma patient

Attempts at prehospital fluid replacement should not delay the patient's transfer to hospital. Before bleeding has been stopped, a strategy of controlled fluid resuscitation should be adopted. Thus, the risk of organ ischaemia is balanced against the possibility of provoking more bleeding with fluids. Once haemorrhage is controlled, normovolaemia should be restored and fluid resuscitation targeted against conventional endpoints, the base deficit, and plasma lactate. Initially, the precise fluid used is probably not important, as long as an appropriate volume is given; anaemia is much better tolerated than hypovolaemia. Colloids vary substantially in their pharmacology and pharmacokinetics and the experimental findings from one cannot be extrapolated reliably to another. We still lack reliable data to prove that any of the colloids reduce mortality in trauma patients. In the presence of SIRS, hydroxyethyl starch may reduce capillary leak. Hypertonic saline solutions may have some benefit in patients with head injuries although this has yet to be proven beyond doubt. It is likely that one or more of the haemoglobin-based oxygen carriers currently under development will prove to be valuable in the treatment of the trauma patient.

A multimedia approach to raising awareness of information and communications technology amongst healthcare professionals

This study is concerned with the application of advanced multimedia technology to the development of a programme aimed at raising awareness of information and communications technology (ICT) amongst health professionals in Ireland. The programme is delivered in the form of a symposium supplemented by a multimedia CD and associated web site. It examines how ICT can be used effectively in healthcare across all sectors - primary, secondary and tertiary - with a strong emphasis on supporting shared care. The aim is to empower users to make informed technological choices and to actively participate in the exploitation of ICT in the health sector. The programme was successfully completed and delivered to over 2300 health professionals across Ireland and follow-up activities include the active encouragement of leaders and champions within the sector. This will be supported by interactive web-based education and training material focused on specialised topics of particular interest within the broader context of continuing medical education (CME).

"Recommendations for uniform reporting of data following major trauma--the Utstein style" (as of July 17, 1999). An International Trauma Anaesthesia and Critical Care Society (ITACCS)

Basic and advanced care of trauma patients has always been an important aspect of prehospital and immediate in-hospital emergency medicine, involving a broad spectrum of disciplines, specialties and skills delivered through Emergency Medical Services Systems which, however, may differ significantly in structure, resources and operation. This complex background has, at least in part, hindered the development of a uniform pattern or set of criteria and definitions. This in turn has hitherto rendered data incompatible, with the consequence that such differing systems or protocols of care cannot be readily evaluated or compared with acceptable validity. Guided by previous consensus processes evolved by the ERC, the AHA and other International Organizations--represented in ILCOR--on 'Uniform reporting of data following out-of-hospital and in-hospital cardiac arrest--the Utstein style' an international working group of ITACCS has drafted a document, 'Recommendations for uniform reporting of data following major trauma--the Utstein style'. The reporting system is based on the following considerations: A structured reporting system based on an "Utstein style template" which would permit the compilation of data and statistics on major trauma care, facilitating and validating independent or comparative audit of performance and quality of care (and enable groups to challenge performance statistics which did not take account of all relevant information). The recommendations and template should encompass both out-of-hospital and in-hospital trauma care. The recommendations and template should further permit intra- and inter-system evaluation to improve the quality of delivered care and identification of the relative benefits of different systems and innovative initiatives. The template should facilitate studies setting out to improve epidemiological understanding of trauma; for example such studies might focus on the factors that determine survival. The document is structured along the lines of the original Utstein Style Guidelines publication on 'prehospital cardiac arrest'. It includes a glossary of terms used in the prehospital and early hospital phase and definitions, time points and intervals. The document uses an almost identical scheme for illustrating the different process time clocks--one for the patient, one for the dispatch centre, one for the ambulance and, finally, one for the hospital. For clarity, data should be reported as core data (i.e. always obtained) and optional data (obtained under specific circumstances). In contrast to the graphic approach used for the Utstein template for pre- or in-hospital cardiac arrest, respectively, the present template introduces, for the time being, at least, a number of terms and definitions and a semantic rather than a graphic report form. The document includes the following sections: The Section Introduction and background The Section on Trauma Data Structure Development: presents a general outline of the development of structured data using object-orientated modelling (which will be discussed in due course) and includes a set of explanatory illustrations. The Section on Terms and Definitions: outlines terms and definitions in trauma care, describing different types of trauma (blunt, penetrating, long bone, major/combined, multiple/polytrauma and predominant trauma). The Section on Factors relating to the circumstances of the injury describes the following items: cause of injury (e.g. type of injury (blunt or penetrating), burns, cold, crush, laceration, amputation, radiation, multiple, etc. Severity of Injury e.g. prehospital basic abbreviated injury score developed by the working group. The score contains anatomical and physiological disability data, with the anatomical scale ranging ordinally from 1. Head to 9. External; the physiological disability scale ranging ordinally from 0--unsurvivable. Mechanism of injury recording for transportation incidents etc. e.g. the type of impact, po

Reliability of ECG monitoring with a gel pad/paddle combination after defibrillation

Recent warnings have highlighted the possibility of unreliable monitoring through gel pads and paddles when using manual defibrillators. Occasionally, this causes an apparent asystole to be displayed when the true rhythm is ventricular fibrillation. We investigated this phenomenon in the laboratory using defibrillator-testing devices with two different impedances and with two defibrillators (Physio-Control LIFEPAK 9 and Hewlett Packard XL). After delivery of a 200 J shock, the time taken for the original ECG test signal to return to the defibrillator monitor was measured. Measurements were made after each of a series of ten shocks delivered with each defibrillator and gel pad/ testing device combination. Additional measurements were made using self-adhesive combination defibrillator electrodes. When using a low-impedance testing device with gel pads, on all occasions the initial rhythm reappeared immediately. When using the high-impedance testing device, the post shock rhythm was initially displayed as 'no signal' (Hewlett Packard XL) or 'asystole' (Physio-Control LIFEPAK 9). Over the series of ten shocks, the time to return of the original signal ranged between 24 and 154 s with the Hewlett Packard and 17-61 s with the Physio-Control LIFEPAK 9. The time for return of the signal increased with successive shocks. When using Fast-Patch electrodes, the original test signal always returned immediately. We conclude that after the delivery of a shock, monitoring through gel pads may result in the display of spurious asystole being displayed. This is more likely to occur in the presence of high chest impedance and with an increasing number of shocks delivered through the same gel pads. If defibrillator paddles and gel pads have been used for 'quick-look' monitoring, and 'asystole' is displayed after delivery of a shock, the rhythm should be confirmed immediately with monitoring leads.

The relative importance of NADPH: cytochrome c (P450) reductase for determining the sensitivity of human tumour cells to the indolequinone EO9 and related analogues lacking functionality at the C-2 and C-3 positions

Analogues of EO9 (3-hydroxymethyl-5-aziridinyl-1-methyl-2[1H-indole-4-7-dione]prop-2-e n-1-ol) which lack functionality at either the C-2 or C-3 position were synthesised. The aim was to establish the importance of each group towards toxicity and to give an indication as to whether substitution at either position altered activation and toxicity after metabolism by cellular NADPH: cytochrome c (P450) reductase (P450R). MDA231 breast cancer cells were transfected with the cDNA for human P450R and stable clones were isolated. These high P450R-expressing clones were used to determine the aerobic and hypoxic toxicity of EO9 and the two analogues that lacked functionality at either C-2 or C-3. The results showed that P450R was strongly implicated in the bioactivation of EO9 and its analogues under both of these conditions. This data also showed that the C-3 functionality was primarily implicated in hypoxic toxicity.

An IT awareness programme for the health sector in Ireland

This paper describes an Awareness Programme delivered throughout Ireland which aims to increase the level of understanding of healthcare professionals as to the benefits of Information and Communications Technology (ICT) and of emerging trends in Health Informatics in Europe. The programme examines the use of ICT across the whole health sector--primary, secondary and tertiary. It has been delivered at over 30 centres to more than 1500 health professionals.

Evidence for complement-dependent and -independent inhibition of insulin secretion from clonal beta-cells incubated in the presence of sera of newly diagnosed IDDM patients

There are conflicting reports on the effect of serum from patients with insulin-dependent diabetes mellitus (IDDM) or normal human serum on beta-cell function and insulin secretion. Here, we report that the sera of newly diagnosed IDDM patients potently suppresses insulin secretion from a clonal rat pancreatic beta-cell line (BRIN-BD11), but do not alter cell viability. Indeed, the viability of the beta-cells was not significantly different between cells cultured in 10% (v/v) IDDM sera, normal human sera, or fetal calf serum after 24, 48 and 72 h. Alanine-stimulated insulin secretion from cells cultured for 24 h in (10% v/v) IDDM patient sera was reduced to 48% of that secreted from cells cultured in (10% v/v) normal human sera. After depletion of the complement components C1q and C3, the inhibition of insulin secretion induced by IDDM patient sera was significantly reversed (no significant difference was observed between cells cultured in complement-depleted IDDM patient sera and cells cultured in normal human sera or complement-depleted normal human sera). The concentration of glutamic acid decarboxylase (GAD) autoantibodies was markedly increased in the sera of six out of nine newly diagnosed IDDM patients in this study, whereas insulin auto-antibodies (IAA) were detected in the sera of three of the nine patients and islet-cell antibodies (ICA) in the sera of five of them. In addition, the concentration of soluble terminal complement complexes (SC5-9) was greater in some of the beta-cell culture media samples after 24 h incubation when the incubation medium was supplemented with IDDM patient sera than when supplementation was with normal human sera. We propose that the mechanism of sera-induced inhibition of insulin secretion from clonal beta-cells may involve complement- and cytokine-stimulated intracellular events that attenuate the metabolite-induced secretory process.

Anaesthesia and pain management in cerebral palsy

Cerebral palsy is the result of an injury to the developing brain during the antenatal, perinatal or postnatal period. Clinical manifestations relate to the area affected. Some of the conditions associated with cerebral palsy require surgical intervention. Problems during the peri-operative period may include hypothermia, nausea and vomiting and muscle spasm. Peri-operative seizure control, respiratory function and gastro-oesophageal reflux also require consideration. Intellectual disability is common and, in those affected, may range from mild to severe. These children should be handled with sensitivity as communication disorders and sensory deficits may mask mild or normal intellect. They should be accompanied by their carers at induction and in the recovery room as they usually know how best to communicate with them. Postoperative pain management and the prevention of muscle spasm is important and some of the drugs used in the management of spasm such as baclofen and botulinum toxin are discussed. Epidural analgesia is particularly valuable when major orthopaedic procedures are performed.

A two-year, double-blind comparison of estrogen-androgen and conjugated estrogens in surgically menopausal women. Effects on bone mineral density, symptoms and lipid profiles

OBJECTIVE

To compare the effects of two doses of conjugated equine estrogen (CEE) and two of esterified estrogen plus methyltestosterone (E + A) in surgically menopausal women.

STUDY DESIGN

A two-year, parallel-group, double-blind study of 311 women who were randomly assigned to one of four regimens: (1) CEE, 0.625 mg/d; (2) CEE, 1.25 mg/d; (3) esterified estrogens, 0.625 mg, + methyltestosterone, 1.25 mg/d; or (4) esterified estrogens, 1.25, + methyltestosterone, 2.5 mg/d. Study parameters were symptoms, lipids, bone mineral density, side effects and safety.

RESULTS

All treatments prevented loss of bone in the spine and hip. The higher E + A dose increased spine and hip BMD more than other treatments (P < .002). All treatments improved menopausal symptoms, with non-significantly greater improvements in well-being and sexual interest in the E + A groups. Similar and significant decreases in low-density lipoprotein were observed in all groups, but high-density lipoprotein and triglycerides were increased only in the unopposed estrogen groups (P < .05). Hirsutism was uncommon and similar in all groups at two years. Discontinuation rates and reasons for withdrawal from the study were similar in both groups. No clinically significant side effects or laboratory test abnormalities were seen.

CONCLUSION

As compared to estrogen alone, E + A significantly improved BMD and was well tolerated in surgically menopausal women.

Digoxin and mortality in chronic heart failure. UK Heart Investigation

Data from recent clinical trials suggest digoxin is now widely used in patients with chronic heart failure in sinus rhythm. We present data from a heart failure registry that reiterates concerns about the safety of digoxin in this population.

The relationship between QT intervals and mortality in ambulant patients with chronic heart failure. The united kingdom heart failure evaluation and assessment of risk trial (UK-HEART)

AIMS

Mortality in patients with heart failure remains high and is difficult to predict. QT interval parameters on a 12-lead ECG have been shown to predict arrhythmic events in patients with a variety of myocardial diseases. There is some, but not consistent, evidence that QT interval parameters may act as predictors of mortality, in particular sudden death, in patients with heart failure. In an adequately powered prospective study we have studied QT interval parameters in patients with stable chronic heart failure in order to determine whether they are predictive of all-cause mortality or mode of death.

METHODS AND RESULTS

Five hundred and fifty-four ambulant outpatients with chronic heart failure were recruited. A 12-lead ECG, chest radiograph, echocardiogram, 24 h ambulatory electrocardiogram and serum for biochemical analysis were obtained at baseline. Patients were followed for 471+/-168 days. QT intervals were measured in all leads blinded to patient's characteristics and outcome, were corrected for heart rate, and the maximum QT intervals, and QT dispersion (range of QT intervals) were determined. The same parameters were determined for JT intervals. The primary end-point was all-cause mortality, secondary end-points were sudden cardiac death and death due to progressive heart failure. Multivariate analysis with the Cox's proportional hazards model was used to determine which variables were independently related to outcome. Four hundred and ninety-five patients had analysable ECGs at study entry and of these 71 died during follow-up. The heart rate corrected QT dispersion and maximum QT interval were significant univariate predictors of all-cause mortality (P=0.026 and <0.0001 respectively), and also of sudden death and progressive heart failure death, but were not related to outcome in the multivariate analysis. The independent predictors of all-cause mortality were cardiothoracic ratio (P=0.0003), creatinine (P=0.0009), heart rate (P=0.007), echocardiographically derived left ventricular end-diastolic dimension (P=0.007) and ventricular couplets on 24 h electrocardiographic monitoring (P=0.015).

CONCLUSION

In an adequately powered prospective study none of the QT or JT parameters were shown to be independent predictors of outcome in patients with mild to moderate congestive heart failure. These variables do not therefore add to the prognostic information which can be gained from simple radiographic, biochemical, echocardiographic and Holter data in this group of patients.

Effect of active compression-decompression resuscitation (ACD-CPR) on survival: a combined analysis using individual patient data

Active compression decompression resuscitation (ACD-CPR) has been developed as an alternative to standard cardiopulmonary resuscitation (S-CPR). To determine the effect of ACD-CPR on survival and neurologic outcome in patients with out-of-hospital cardiac arrest, this combined analysis involved individual patient data from 2866 patients from seven separate randomized prospective prehospital studies who had received ACD-CPR or S-CPR after out-of-hospital cardiac arrest in seven international sites. Significant improvement in 1-h survival (odds ratio (OR) = 0.83; confidence interval (CI): 0.695-0.99; P < 0.05) was found with ACD-CPR (n = 1410) versus S-CPR (n = 1456). The odds ratio for hospital discharge after ACD-CPR was similar (OR = 0.82; CI: 0.609-1.107, P = NS), but this finding was not statistically significant. Using the chi2-test for trend, there was a significant improvement in overall survival with ACD-CPR (P < 0.05) versus S-CPR. This improvement was largely due to the influence of results from one study site. Neurological outcome and complication rates were comparable between groups. Further study is needed to determine which emergency medical services systems may benefit from out-of-hospital use of ACD-CPR.

Autonomic dysfunction in patients with nocturnal hypoventilation in extrapulmonary restrictive disease

In chronic obstructive pulmonary disease, persistent hypoxia may be associated with autonomic dysfunction. The effect of nocturnal oxygen desaturation on autonomic function in patients with chest wall deformities and neuromuscular disease is unknown. This study examined the effect of nocturnal oxygen desaturation upon heart rate variability, a sensitive measure of autonomic function. Twenty-seven patients with chest wall deformity or neuromuscular disease underwent analysis of overnight oximetry, blood gases, and 24 h heart rate variability (HRV), specifically the standard deviation of normal-to-normal (SDNN) RR intervals, and the number of increases in successive NN intervals >50 ms (SNN50). Subjects were grouped according to nocturnal arterial oxygen saturation (Sa,O2): group 1 had episodes of Sa,O2 <90%, group 2 had Sa,O2 >90% throughout the night, and group 3 were 27 healthy age-matched controls who also underwent HRV analysis. The mean+/-SD SDNN for group 1 was 79.3+/-23.7 ms, less than group 2 (149.8+/-58.9 ms, p<0.02) and group 3 (155.1+/-37.1 ms, p<0.001). The geometric mean sNN50 was less in group 1 than group 2 (1,530 versus 5,843, p<0.01), but not significantly different from group 3 (2,712, p=0.053). There was no significant difference between groups 2 and 3. Within group 1, both SDNN and sNN50 were significantly lower in those patients with more severe nocturnal hypoxia. The minimum overnight Sa,O2 was the best predictor of abnormal HRV. In conclusion, patients with nocturnal hypoxia have evidence of autonomic dysfunction, even in cases with only transient episodes of nocturnal oxygen desaturation. The severity of autonomic dysfunction is related to the degree of nocturnal oxygen desaturation.

Rehabilitation, chronic illness and disability: the missing elements in nurse education

Chronic illnesses represent one of the most significant health challenges in all developed countries and currently there is considerable debate about how to meet the rehabilitative needs of chronically ill and disabled people. The literature suggests that nursing has a potentially significant, but largely unrealized, role to play in addressing areas of current deficit. However, to fulfil this potential it is vital that the educational preparation of nurses at both qualifying and post-qualifying levels equips them with the necessary knowledge and skills. This paper describes a study which analysed curriculum documents from an extensive range of courses in the United Kingdom (UK) in order to determine the emphasis placed on rehabilitation, chronic illness and disability. The results reveal the overall lack of attention given to these important areas and the superficial manner in which key concepts are addressed. The need to identify more clearly the nursing contribution to rehabilitation is highlighted and indicative areas of knowledge and skill required to develop an expanded role are presented.

Prodrugs for targeting hypoxic tissues: regiospecific elimination of aspirin from reduced indolequinones

A series of regioisomeric derivatives of a 1-methylindole-4,7-dione were synthesised, substituted with a 2-acetoxybenzoate leaving group linked through the (indol-2-yl)methyl or (indol-3-yl)methyl (or propenyl) positions. Reductive elimination of the leaving group occurred from the (indol-3-yl)methyl derivatives but not the 2-substituted regioisomers, indicating that only the C-3 position may be utilised in bioreductively-activated drug delivery, which was demonstrated with an aspirin prodrug.

Fluid replacement

Appropriate fluid replacement is an essential component of trauma patient resuscitation. Once haemorrhage is controlled, the restoration of normovolaemia is a priority. In the presence of uncontrolled haemorrhage, aggressive fluid resuscitation may be harmful. The crystalloid-colloid debate continues, but existing clinical practice is more likely to reflect local biases and dogma rather than evidence-based medicine. Colloids vary substantially in their pharmacology and pharmacokinetics and the experimental findings based on one colloid cannot be extrapolated reliably to another. In the initial stages of trauma patient resuscitation, the precise fluid used is probably not important, as long as an appropriate volume is given. Later, when the microcirculation is relatively leaky, there may be some advantages to colloids such as hydroxyethyl starch. Hypertonic saline solutions may have some benefit in patients with head injuries. A number of haemoglobin solutions are under development but one of the most promising of these has been withdrawn recently. It is highly likely that at least one of these solutions will eventually become routine therapy for trauma patient resuscitation. In the mean time, contrary to traditional teaching, recent data suggest that a restrictive strategy of red cell transfusion may improve outcome in some critically ill patients.

Prospective study of heart rate variability and mortality in chronic heart failure: results of the United Kingdom heart failure evaluation and assessment of risk trial (UK-heart)

BACKGROUND

Patients with chronic heart failure (CHF) have a continuing high mortality. Autonomic dysfunction may play an important role in the pathophysiology of cardiac death in CHF. UK-HEART examined the value of heart rate variability (HRV) measures as independent predictors of death in CHF.

METHODS AND RESULTS

In a prospective study powered for mortality, we recruited 433 outpatients 62+/-9.6 years old with CHF (NYHA functional class I to III; mean ejection fraction, 0.41+/-0.17). Time-domain HRV indices and conventional prognostic indicators were related to death by multivariate analysis. During 482+/-161 days of follow-up, cardiothoracic ratio, SDNN, left ventricular end-systolic diameter, and serum sodium were significant predictors of all-cause mortality. The risk ratio for a 41.2-ms decrease in SDNN was 1.62 (95% CI, 1.16 to 2.44). The annual mortality rate for the study population in SDNN subgroups was 5.5% for >100 ms, 12.7% for 50 to 100 ms, and 51.4% for <50 ms. SDNN, creatinine, and serum sodium were related to progressive heart failure death. Cardiothoracic ratio, left ventricular end-diastolic diameter, the presence of nonsustained ventricular tachycardia, and serum potassium were related to sudden cardiac death. A reduction in SDNN was the most powerful predictor of the risk of death due to progressive heart failure.

CONCLUSIONS

CHF is associated with autonomic dysfunction, which can be quantified by measuring HRV. A reduction in SDNN identifies patients at high risk of death and is a better predictor of death due to progressive heart failure than other conventional clinical measurements. High-risk subgroups identified by this measurement are candidates for additional therapy after prescription of an ACE inhibitor.

Developing nursing's future role. 2: Nurses' job satisfaction and morale

This, the second of two articles, presents the results of a recent survey of nurses' job satisfaction and morale undertaken at the Northern General Hospital NHS Trust, Sheffield. The survey was conducted in order to provide a benchmark against which to gauge progress towards creating a work environment in which nurses are able to exercise maximum autonomy within a supportive and enabling culture. The results mirror recent national reports which highlight the increasing tension between workload pressures and the desire to provide holistic patient care. A number of factors were identified which suggest the need for remedial action across a range of fronts. Such factors are briefly described, together with the action taken to date to address the issues raised.

Indolequinone bioreductive drugs: kinetic factors which influence selectivity for hypoxia

The factors influencing the kinetics of the oxygen-sensitive reduction of indolequinones, including those bearing leaving groups in the (indol-3-yl)methyl position, have been studied. The hydroquinones derived from some representative indolequinones were found to autoxidize slowly in oxygenated solution at rates (effective rate constant with O2 approximately 40-300 M-1 s-1) that cannot compete with the reductive elimination of leaving groups. The rates of reaction between hydroquinone and O2 were even slower in the presence of approximately 4 microM superoxide dismutase (effective rate constant approximately 2-7 M-1 s-1), indicating the role of superoxide radicals in hydroquinone autoxidation. Since the release of the leaving groups from the hydroquinones is not significantly oxygen-sensitive, tumour selectivity requires specific reduction by enzymes that are overexpressed in some tumours. Conversely, the release of leaving groups from semiquinone radicals is inhibited by oxygen too efficiently unless the semiquinone reacts with targets on a timescale of milliseconds. Modification of redox properties has been explored with the aim of changing this oxygen sensitivity. The new 2-phenylindolequinones are approximately 60-100 mV higher in reduction potential than 2-alkyl derivatives but this is insufficient to decrease the rate of electron transfer from semiquinone to oxygen to a degree which might confer hypoxia-selective cytotoxicity. These results are discussed in the context of toxicity of EO9 and related compounds towards hypoxic rather than anoxic cells.

Autonomic assessment of cardiovascular disease

Autonomic dysfunction plays a major role in the pathophysiology of many medical conditions, particularly cardiovascular disorders and diabetes mellitus. This article describes some of the methods used to assess cardiovascular autonomic function, and concentrates on the techniques that have a current or potential clinical application.

Indolequinone antitumor agents: reductive activation and elimination from (5-methoxy-1-methyl-4,7-dioxoindol-3-yl)methyl derivatives and hypoxia-selective cytotoxicity in vitro

A series of indolequinones bearing a variety of leaving groups at the (indol-3-yl)methyl position was synthesized by functionalization of the corresponding 3-(hydroxymethyl)indolequinone, and the resulting compounds were evaluated in vitro as bioreductively activated cytotoxins. The elimination of a range of functional groups-carboxylate, phenol, and thiol-was demonstrated upon reductive activation under both chemical and quantitative radiolytic conditions. Only those compounds which eliminated such groups under both sets of conditions exhibited significant hypoxia selectivity, with anoxic:oxic toxicity ratios in the range 10-200. With the exception of the 3-hydroxymethyl derivative, radiolytic generation of semiquinone radicals and HPLC analysis indicated that efficient elimination of the leaving group occurred following one-electron reduction of the parent compound. The active species in leaving group elimination was predominantly the hydroquinone rather than the semiquinone radical. The resulting iminium derivative acted as an alkylating agent and was efficiently trapped by added thiol following chemical reduction and by either water or 2-propanol following radiolytic reduction. A chain reaction in the radical-initiated reduction of these indolequinones (not seen in a simpler benzoquinone) in the presence of a hydrogen donor (2-propanol) was observed. Compounds that were unsubstituted at C-2 were found to be up to 300 times more potent as cytotoxins than their 2-alkyl-substituted analogues in V79-379A cells, but with lower hypoxic cytotoxicity ratios.

Rehabilitation: scope for improvement in current practice

This article concludes this part of the rehabilitation series by looking at the nursing contribution to rehabilitation. It brings together the common elements which have emerged in the previous seven articles, identifying areas in which there is considerable scope for improvement to current practice. Indicative areas of knowledge and skill required for nurses to play a more active role are considered and a number of potential models are briefly described.

The United Kingdom pre-hospital study of active compression-decompression resuscitation

This prospective, controlled trial with crossover group design compares the effectiveness of active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) and standard CPR on the outcomes of victims of prehospital cardiac arrest. In three UK cities, victims of non-traumatic, out of hospital cardiac arrest, over the age of 8 years received either standard or ACD-CPR on arrival of ambulance personnel. Main outcome measures were return of spontaneous circulation, survival to be admitted to the intensive care unit, survival to hospital discharge, and neurological outcome. A total of 576 patients (STD-CPR, n=309; ACD-CPR, n=267) were analysed. The treatment groups were similar with respect to age, gender, proportion of witnessed arrests, initial cardiac rhythm, and call to advanced life support interval. The proportion of patients receiving bystander CPR was higher in the ACD group (37.1% vs. 28.5%; P=0.028). The interval between collapse and defibrillation was longer in the ACD group (12.3 min vs. 10.4 min; P=0.028). There was no difference between the STD-CPR and ACD-CPR groups in survival to admission to the intensive care unit (13.6% vs. 13.8%; P=0.93) or hospital discharge (4.8% vs. 6.0%; P=0.67). There was no difference between the groups with respect to the neurological outcome of those patients surviving to hospital discharge. Analysis of important subgroups also showed no benefit for ACD-CPR. We conclude that there was no improvement in outcome with ACD-CPR when used by ambulance personnel in Cardiff and Portsmouth.

Stroke 2: expanding the nurse's role in stroke rehabilitation

This article, the second of two considering the nurse's role in stroke rehabilitation, focuses on potential nursing contributions in a number of areas. There is scope, particularly in the community, to develop a far greater nursing role in both the acute and the postacute phases of rehabilitation. However, nurses often have ambivalent attitudes towards rehabilitation--seeing acute care as more prestigious and important. Such attitudes are developed and reinforced in basic training which gives relatively little emphasis to chronic illness.