Search PubMed⌕ Search

Biomedical subjects

P Davey

Publications and source records attributed to P Davey.

At least 37 records · Page 2Linked to original sources
PubMed2001

The epic project: developing national evidence-based guidelines for preventing healthcare associated infections. Phase I: Guidelines for preventing hospital-acquired infections. Department of Health (England).

In 1998, the Department of Health (England) commissioned the first phase of national evidence-based guidelines for preventing healthcare associated infections. These focused on developing a set of standard principles for preventing infections in hospitals together with guidelines for preventing hospital-acquired infections (HAI) associated with the use of short-term indwelling ureteral catheters in acute care and with central venous catheters in acute care. These guidelines are systematically developed broad statements (principles) of good practice that all practitioners can use and which can be incorporated into local protocols. A nurse-led, multi-professional team composed of infection prevention practitioners, clinical microbiologists/retrovirologist, epidemiologists, and researchers developed the guidelines. A rigorous guideline development process was used to inform the systematic reviews, the clinical and critical appraisal of relevant evidence, and linking that evidence to evolving guidelines. Both general and specialist clinical practitioners were involved in all stages of developing these guidelines, as were representatives from relevant Royal Colleges, learned societies, other professional organisations and key stakeholders. The introduction to these guidelines describes a robust and validated guideline development model that can be used by others to develop future guidelines. This model is described in more detail in the associated technical reports that can be found on the project web site http://www.epic.tvu.ac.uk. Locating and appropriately using good quality evidence to inform guideline development in this field is challenging. Evidence from rigorously conducted experimental studies was frequently limited and consequently a range of other types of evidence were systematically retrieved and carefully appraised. The concluding discussion on implementation highlights potential issues for clinical governance and areas for future research and suggests issues that need to be addressed to allow practitioners to successfully incorporate these guidelines into routine clinical practice.

Acute Disease↗
PubMed2001

Self-efficacy and goal importance in the prediction of physical disability in people following hospitalization: a prospective study.

OBJECTIVES: This prospective study evaluates the role of self-efficacy and goal importance in predicting decreases in disability in activities of everyday living. METHOD: Disability, self-efficacy and goal importance were each assessed before and at 3 and 9 months after participants underwent joint replacement surgery. RESULTS: Disability had decreased at 3 and 9 months post-surgery assessments. Self-efficacy beliefs were higher at 3 and 9 months following surgery while goal importance was increased at 9 months but not at 3 months. Medical variables and prior disability predicted disability at 3 months. Social-cognitive variables did not contribute to the prediction of 3 months disability. Pre-surgery goal importance and self-efficacy at 3 months were independent predictors of disability at 9 months after controlling for pre-surgery and 3 months disability. Evidence also suggested that goal importance and self-efficacy interacted to predict levels of disability at 9 months following surgery. CONCLUSIONS: The findings demonstrate that recovery is governed not solely by medical phenomena but also by psychological variables and suggest that modification of these variables may have an impact on recovery outcomes. Moreover, attention should be paid to the timing of such intervention and to the length of follow-up.

Journal Article↗
PubMed2001

Is amiodarone an underrecognized cause of acute respiratory failure in the ICU?

Amiodarone is a commonly used anti-arrhythmic agent, with well-recognized chronic toxicity. Less well known is amiodarone's potential to cause acute lung damage, which can be severe or, occasionally, life-threatening. Lungs that have already been exposed to physical insults, such as the lungs of patients undergoing cardiac surgery, are particularly susceptible to acute pulmonary toxicity (APT). Unfortunately, cardiac surgery is one of the clinical scenarios in which amiodarone is most commonly used. After reviewing the data, and even in the context of difficulties and discrepancies in the existing literature, we contend that there is sufficient evidence of amiodarone's potentially serious side-effect profile in surgical ICU patients to advise continued caution in its use with this severely ill patient group. We suggest that amiodarone has a potentially important, though underrecognized, role in inducing an APT/ARDS in some patients, such as those undergoing cardiac surgery. We also provide a hypothesis to explain the mechanism by which amiodarone causes lung damage.

Acute Disease↗
PubMed2000

QT interval lengthening in cardiac disease relates more to left ventricular systolic dysfunction than to autonomic function.

BACKGROUND: There are multiple influences on the QTc interval, including the autonomic nervous system. Which influence is the principal determinant of the variation in QTc interval between different cardiac diseases is not yet clear, though some studies have suggested that the QTc interval primarily reflects sympatho-vagal balance. This study investigated this claim further. AIM: To determine if autonomic tone was the prime determinant of variation in the QTc interval between subjects with different cardiac diseases. METHODS: Subjects with different cardiac diseases were studied, QTc interval determined and correlated with three different measures of the autonomic nervous system, that of baroreflex sensitivity, catecholamine levels (epinephrine and norepinephrine) and sympatho-vagal balance as determined by power spectrum analysis. RESULTS: 47 subjects were studied, comprising 17 subjects with heart failure, 14 subjects with left ventricular hypertrophy and 16 control subjects. For the group as a whole there was no relationship between QTc interval and any measure of the autonomic nervous system function, but there was a reasonable relationship between fractional shortening and QTc interval (r=0.47, P<0.003). For subjects with an echocardiographic fractional shortenings less than 0.35 (which correlates with an ejection fraction of <50%), a strong relationship between fractional shortening and QTc interval remained (r=0.57, P<0.002), but in addition a relationship between QTc interval and catecholamine levels developed (for epinephrine: r=0.67, P<0.002; and for norepinephrine: r=0.62, P<0.005). Multiple regression analysis showed that fractional shortening and epinephrine levels were independently related to QTc interval. CONCLUSION: In subjects with a variety of cardiac diseases, the prime determinant of QTc interval is left ventricular systolic performance rather than the autonomic nervous system, though in subjects with low normal and less fractional shortenings catecholamine levels are independently related to QTc interval.

Autonomic Nervous System↗
PubMed2000

Drug induced chest pain-rare but important.

Pericarditis, usually viral in origin, is an infrequent cause of chest pain. Pericarditis due to drug allergy is even less frequent and is thus rarely considered in the differential diagnosis. A case is reported of a woman who presented with severe chest pain, caused by minocycline induced pericarditis. Such allergy may be more common than reported. It is suggested that drug induced pericarditis should be included in the differential diagnosis of acute chest pain.

Acute Disease↗
PubMed2000

Not so simple cystitis: how should prescribers be supported to make informed decisions about the increasing prevalence of infections caused by drug-resistant bacteria?

Trimethoprim is a safe, effective, and inexpensive treatment for cystitis. However, at least 25% of bacteria isolated from urine samples in general practice are now resistant to trimethoprim in the laboratory. The relationship between laboratory resistance and clinical outcome is complex. Cephalexin appears to be more active than trimethoprim in the laboratory but has been consistently less effective in clinical trials. There is little point in collecting data about the prevalence of drug resistance in urinary bacteria unless it is linked to evidence about the impact of resistance on clinical outcomes. Pragmatic clinical trials are required to provide practices with clear thresholds for managing their antibiotic policies; for example, 'Change from trimethoprim to drug X when the probability of trimethoprim resistance reaches Y%.' Prescribers should be aware that trimethoprim resistance is most likely to occur in patients who have been exposed to trimethoprim or other antibiotics in the previous six months, and that the risk increases with age. This information could be used to stratify women according to risk of infection by trimethoprim-resistant bacteria. Health education leaflets are an effective method for reducing the frequency of recurrent cystitis. Symptomatic treatment can control symptoms and allow time for microbiological investigation. Both of these strategies may help to reduce unnecessary prescribing of antibiotics in general and quinolones in particular.

Adult↗
PubMed1999

Heart rate and catecholamine contribution to QT interval shortening on exercise.

BACKGROUND: QT interval shortens with exercise. Some of this shortening is due to an increase in heart rate, and some is due to other effects of exercise, probably mostly neuroendocrine effects. Data from subjects with cardiac transplants have suggested that non-heart rate-related changes in QT interval on exercise are due to the effects of circulating catecholamines. HYPOTHESIS: We sought to determine whether changes in plasma catecholamine levels with exercise are an important contributor to non-heart rate-related QT interval shortening. METHODS: Subjects with DDD pacemakers were recruited. Subjects had QT intervals measured at rest, during a low fixed level exercise test designed to increase heart rate to about 110 beats/min, and, after resting, during pacing at a heart rate of 110 beats/min. Catecholamine levels were measured at each stage of the study. RESULTS: QT interval at rest was 420 +/- 12 ms, during pacing 366 +/- 16 ms, and on exercise 325 +/- 14 ms. This then gave the proportion of QT interval shortening due to heart rate as 68.6 +/- 9.3% of total QT shortening, with the range between 35 and 95.6%. There was no proportionality between the degree of QT interval shortening on exercise that was not due to increases in heart rate and changes in plasma catecholamine levels. CONCLUSION: Two-thirds of exercise-induced QT interval shortening are due to an increase in heart rate, and one-third to other effects. Changes in plasma catecholamine levels on exercise were not closely related to changes in the QT interval on exercise.

Aged↗
PubMed1999

Cost-effectiveness of prophylactic nasal mupirocin in patients undergoing peritoneal dialysis based on a randomized, placebo-controlled trial.

The study objective was to measure the benefits of elimination of nasal carriage of Staphylococcus aureus by calcium mupirocin ointment in patients undergoing continuous ambulatory peritoneal dialysis. The design was a prospective, placebo-controlled, randomized clinical trial. The subjects were 267 patients recruited from nine renal units in Belgium, France and the UK. The main outcome measures were the rate of catheter exit site infection (ESI), rates of other infections and healthcare costs from the perspective of a hospital budget-holder. The rate of ESI caused by S. aureus was significantly reduced from one in 28.1 patient months to one in 99.3 patient months (P = 0.006) and there were also non-significant trends towards lower rates of ESI caused by any organism and peritonitis caused by S. aureus. In comparison with the placebo group, patients in the mupirocin group with ESI had lower antibiotic (P = 0.02) and hospitalization costs (P = 0.065). However, overall costs of antibiotic treatment, for all infections combined, were not significantly different (P = 0.2) and total antibiotic costs (including mupirocin) were significantly higher in the mupirocin group (P = 0.001). Mupirocin prophylaxis would have been cost-neutral if the rate of ESI increased to >75% in the placebo group, or if all healthcare costs increased by 40%, or if the cost of screening was reduced from Pound Sterling 15 to Pound Sterling 3 per patient, or if the cost of mupirocin treatment was reduced from Pound Sterling 93 to Pound Sterling 40 per patient year. In conclusion, savings in healthcare costs are unlikely to be sufficiently great to offset the cost of mupirocin and screening for nasal carriage of S. aureus. The decision about whether or not to implement mupirocin should depend on a local analysis of the value of preventing ESIs caused by S. aureus.

Administration, Intranasal↗
PubMed1999

A new physiological method for heart rate correction of the QT interval.

AIM: To reassess QT interval rate correction. BACKGROUND: The QT interval is strongly and inversely related to heart rate. To compare QT intervals between different subjects with different heart rates requires the application of a QT interval rate correction formula. To date these formulae have inappropriately assumed a fixed relation between QT interval and heart rate. An alternative method of QT interval rate correction that makes no assumptions about the QT interval-heart rate relation is needed. PROPOSAL: A QT heart rate correction method should maintain or accentuate biological QT interval variability, should totally remove the dependence of the rate corrected QT interval on heart rate, and should be applicable over a wide range of conditions with a wide range of differing autonomic states. METHODS: QT intervals were obtained at rest and during exercise from subjects expected to have different QT intervals and different QT interval-heart rate relations. A linear regression line was obtained from the exercise test data, and the QT interval at a notional heart rate of 60 and 0 beats/min, termed the QT(60) interval, and the QT y intercept obtained by back calculation. RESULTS: QT(60) and QT y intercept values were prolonged in heart failure compared with either left ventricular hypertrophy or controls. There was no relation between heart rate and either QT(60) or QT y intercept CONCLUSIONS: This new physiologically based method of correcting QT interval for heart rate removes the dependence of the corrected QT interval on heart rate, and maintains biological differences.

Cardiac Output, Low↗
PubMed1999

A young man with a heavy heart.

A 34 year old man presented with acute chest pain. His ECG was very abnormal but stable and he was treated with opiate analgesia. When his condition did not improve, chest radiography and cardiac ultrasound were performed. Both revealed metal dense deposits in the heart. On questioning, the patient revealed that he had self injected with mercury 15 years before. Self injection of elemental mercury is rare but well described and normally used by those who are suicidally depressed or who seek to improve sexual or athletic performance. Intravenous mercury may be deposited in the right heart and can result in ECG abnormalities, which may later be mistaken for changes due to coronary or other cardiac disease and result in inappropriate medication and hospitalisation.

Adult↗
PubMed1999

Spontaneous rupture of a saphenous vein graft.

We present a case of spontaneous rupture of a right coronary bypass vein graft in a 57-year-old woman 10 years after coronary by-pass surgery. Although rare, this diagnosis should be considered in such patients presenting with appropriate symptoms.

Aneurysm, False↗
PubMed1999

Assessment of chronic heart failure using gas exchange: which variable and when to correct for body mass.

We investigated whether correction for body mass is appropriate when using variables derived from gas exchange measurements in the assessment of chronic heart failure. Patients with heart failure were studied either on a bicycle ergometer (22 subjects) or on a treadmill (28 subjects). For bicycle exercise testing either peak V(O2) or peak V(CO2) uncorrected for body mass reflected exercise capacity. However, for treadmill exercise, body mass correction was necessary to relate exercise capacity to peak V(O2) or peak V(CO2). Mass correction is therefore appropriate for treadmill but not for bicycle exercise.

Body Mass Index↗
PubMed1999

Cost effectiveness of quinolones in hospitals and the community.

In hospitals, oral quinolone therapy has lower daily associated costs (acquisition and administration) than most intravenous regimens. In addition, oral switch therapy shortens the duration of hospital stay for most patients. However, randomised trials are required to measure the economic impact of the switch to oral therapy in terms of hospital care costs and the burden imposed on community health services, on relatives or carers and on the patient. Evidence about the reliability of absorption of quinolones in hospitalised patients is more likely to be obtained from large population kinetic studies than randomised effectiveness trials. The existing literature on cost effectiveness of quinolones in the community is disappointing. The principal problems are poor definition of diagnostic criteria, inclusion of irrelevant comparator drugs and a failure to include infections caused by bacteria that are resistant to the comparator. Consequently, there is little evidence to support the use of economic models to determine the consequences of antibiotic resistance in the community.

4-Quinolones↗
PubMed1999

Diagnosis and management of osteomyelitis. Decision analytic and pharmacoeconomic considerations.

Osteomyelitis, or bone infection, is becoming more common, largely because of increases in the use of implanted prosthetic devices in the management of arthritis or fractures. The clinical management of osteomyelitis requires accurate microbiological diagnosis that will identify appropriate antibacterials to which the pathogenic organisms are sensitive. Therapy will largely depend on the type of bacteria, the route by which the bacteria reach the bone, the presence of any orthopaedic devices and the patient's ability to mount an immune response. Consequently, therapy often requires a combination of medical and surgical management. The aim of this review is primarily to assess the impact of different drug regimens on the total cost and to clarify the implications of various treatment options for patients with osteomyelitis. Thus, the review examines the link between the main categories of osteomyelitis and common pathogens, and provides additional comments on the aetiology and epidemiology of the condition. At present, there is a real shortage of high quality evidence to guide the decision-maker through the range of available options. One way to deal with the complexity and uncertainty surrounding the management of osteomyelitis is to develop treatment protocols leading to decision trees which will in turn systematically analyse the options available for treating patients with osteomyelitis. Consequently, we have developed a number of decision trees to show the range of options available and have applied these to the relatively simple problem of route of administration of antibacterials. However, even here the available data allow only relatively crude estimations of the costs and consequences of alternative regimens. Thus, the aim has been to provide structures that may help to set priorities for research based on the expected value of new information. In the absence of evidence, there are broadly 2 alternatives. One is based on selection of the least expensive regimen in the absence of evidence to prove that more expensive options are more effective; patients with multiply resistant staphylococci, for which no effective oral regimen is available, should be treated with intravenous therapy. This is consistent with the UK legal system, which is founded on the so-called Bolam test. The alternative is providing the maximum available treatment; in the US, it is more likely that a doctor will be held negligent for not providing the maximum available treatment, and most standard texts recommend routine use of intravenous therapy for osteomyelitis.

Anti-Bacterial Agents↗
PubMed1999

Influence of posture and handgrip on the QT interval in left ventricular hypertrophy and in chronic heart failure.

In certain disease states prolongation of the QT interval has been shown to be arrhythmogenic. Whether QTc interval changes with position and thus whether certain positions are more arrhythmogenic than others is not known for different diseases that predispose to arrhythmias, and was therefore studied. Patients with left ventricular hypertrophy and heart failure, and the appropriate matched controls, were recruited. Subjects were studied in the lying, sitting, standing and squatting positions and had QT intervals determined by computer algorithm 2 min after each position change. After resting, QT interval was determined while the subjects performed maximum handgrip exercise with their dominant hand. QT intervals were rate-corrected using Bazett's method. QTc interval is prolonged in heart failure patients compared with either left ventricular hypertrophy or control subjects in the lying and sitting position, but not in the standing or squatting position. The QTc intervals for heart failure and control subjects were, respectively, 443+/-7 ms versus 421+/-6 ms when lying (P<0.05), 451+/-10 ms versus 419+/-6 ms when sitting (P<0.05), 429+/-10 versus 414+/-7 ms when standing (P not significant) and 437+/-10 versus 419+/-8 ms when squatting (P not significant). The values for patients with hypertrophy did not differ from control values. Maximum handgrip does not affect the QTc interval in heart failure, but prolongs it in both the hypertrophy and control groups. Position and static exercise are important modifiers of QTc interval and their effect depends on the condition of the left ventricle.

Analysis of Variance↗
PubMed1999

Out-patient and home-parenteral antibiotic therapy (OHPAT): evaluation of the impact of one year's experience in Tayside.

OBJECTIVE: An out-patient and home parenteral antibiotic therapy programme for the treatment of suitable infections was developed over a four year period. This paper describes the impact of one year's experience of its implementation on various measures of outcome. DESIGN: Each patient treatment has a full integrated care pathway (ICP) and patient satisfaction questionnaire completed. The ICP documents the clinical progress of the patient and incorporates various measures of quality of care on the 101 number of patients treated from April 1998 to March 1999 are presented here. SETTING: Dundee Teaching Hospitals NHS Trust (now Tayside University Hospitals NHS Trust). SUBJECTS: Patients with a range of infections requiring intravenous antibiotics. MAIN MEASURES: Number of patients treated with various infections, clinical and microbiological outcome, drug and vascular access complication rates, impact on drug costs and in-patient bed days, and measurement of patient satisfaction/quality of life. RESULTS: Patients were treated over a 12 month period. 51.5 per cent had skin & soft tissue infections and 22.8 per cent bone & joint sepsis. 57 per cent of patients received out-patient and 34 per cent self or carer administered home therapy. Ninety-four per cent of patients were cured or improved following treatment. Only 7.5 per cent of patients required an unscheduled admission to hospital. Twelve per cent of patients had some type of vascular device related adverse event (partly due to a faulty batch of lines) and six per cent of patients had a drug related reaction. The additional daily cost of drugs was minimal (< 12 Pounds/day) and more than 1,461 bed days have been saved across the Directorates. The patient satisfaction level was high.

Ambulatory Care↗