Pressure relieving support surfaces: a randomised evaluation

OBJECTIVES

To determine differences between alternating pressure overlays and alternating pressure replacement mattresses with respect to the development of new pressure ulcers, healing of existing pressure ulcers, patient acceptability and cost-effectiveness of the different pressure-relieving surfaces. Also to investigate the specific additional impact of pressure ulcers on patients' well-being.

DESIGN

A multicentre, randomised, controlled, open, fixed sample, parallel-group trial with equal randomisation was undertaken. The trial used remote, concealed allocation and intention-to-treat (ITT) analysis. The main trial design was supplemented with a qualitative study involving a purposive sample of 20-30 patients who developed pressure ulcers, to assess the impact of the pressure ulcers on their well-being. In addition, a focus group interview was carried out with clinical research nurses, who participated in the PRESSURE (Pressure RElieving Support SUrfaces: a Randomised Evaluation) Trial, to explore the experiences of their role and observations of pressure area care.

SETTING

The study took place in 11 hospital-based research centres within six NHS trusts in England.

PARTICIPANTS

Acute and elective patients aged 55 years or older and admitted to vascular, orthopaedic, medical or care of the elderly wards in the previous 24 hours were investigated.

INTERVENTIONS

Patients were randomised to either an alternating pressure overlay or an alternating pressure mattress replacement, with mattress specifications clearly defined to enable the inclusion of centres using products from different manufacturers, and to exclude hybrid mattress systems (which either combine foam or constant low pressure with alternating pressure in one mattress, or can be used as either an overlay or a replacement mattress).

MAIN OUTCOME MEASURES

Development of a new pressure ulcer (grade < or =2, i.e. partial-thickness wound involving epidermis/dermis only) on any skin site. Also healing of existing pressures ulcers, patient acceptability and cost-effectiveness.

RESULTS

In total, 6155 patients were assessed for eligibility to the trial and 1972 were randomised: 990 to the alternating pressure overlay (989 after one postrandomisation exclusion) and 982 to the alternating pressure mattress replacement. ITT analysis found no statistically significant difference in the proportions of patients developing a new pressure ulcer of grade 2 or above [10.7% overlay patients, 10.3% mattress replacement patients, a difference of 0.4%, 95% confidence interval (CI) -2.3 to 3.1%, p = 0.75]. When logistic regression analysis was used to adjust for minimisation factors and prespecified baseline covariates, there was no difference between the mattresses with respect to the odds of ulceration (odds ratio 0.94, 95% CI 0.68 to 1.29). There was no evidence of a difference between the mattress groups with respect to time to healing (p = 0.86). The Kaplan-Meier estimate of the median time to healing was 20 days for each intervention. More patients allocated overlays requested mattress changes due to dissatisfaction (23.3%) than mattress replacement patients (18.9%, p = 0.02) and more than one-third of patients reporting difficulties associated with movement in bed and getting into or out of bed. There is a higher probability (64%) that alternating mattress replacements are cost-saving; they were associated with lower overall costs (74.50 pounds sterling per patient on average, mainly due to reduced length of stay) and greater benefits (a delay in time to ulceration of 10.64 days on average). Patients' accounts highlighted that the development of a pressure ulcer could be pivotal in the trajectory from illness to recovery, by preventing full recovery or causing varied impacts on their quality of life.

CONCLUSIONS

There is no difference between alternating pressure mattress replacements and overlays in terms of the proportion of patients developing new pressure ulcers; however, alternating pressure mattress replacements are more likely to be cost-saving. The results suggest that when renewing alternating pressure surfaces or ordering equipment within a rental contract, mattress replacements should be specified; however, overlays are acceptable if no replacement mattress is available. Similarly, patient preferences can be supported, without any great increase in risk, if individual patients request an overlay rather than a replacement mattress. Further research could include a randomised controlled trial comparing alternating pressure mattress replacements and high-specification foam mattresses in patients at moderate to high risk; an accurate costing study to understand better how much pressure ulcers cost health and social services in the UK; and trials in higher risk groups of patients. Also future trials should measure time to ulceration as the primary end-point, since this is more informative economically and possibly also from a patient and clinical perspective.

A series of systematic reviews to inform a decision analysis for sampling and treating infected diabetic foot ulcers

OBJECTIVES

To review systematically the evidence on the performance of diagnostic tests used to identify infection in diabetic foot ulcers (DFUs) and of interventions to treat infected DFUs. To use estimates derived from the systematic reviews to create a decision analytic model in order to identify the most effective method of diagnosing and treating infection and to identify areas of research that would lead to large reductions in clinical uncertainty.

DATA SOURCES

Electronic databases covering period from inception of the database to November 2002.

REVIEW METHODS

Selected studies were assessed against validated criteria and described in a narrative review. The structure of a decision analytic model was derived for two groups of patients in whom diagnostic tests were likely to be used.

RESULTS

Three studies that investigated the performance of diagnostic tests for infection on populations including people with DFUs found that there was no evidence that single items on a clinical examination checklist were reliable in identifying infection in DFUs, that wound swabs perform poorly against wound biopsies, and that semi-quantitative analysis of wound swabs may be a useful alternative to quantitative analysis. However, few people with DFUs were included, so it was not possible to tell whether diagnostic performance differs for DFUs relative to wounds of other aetiologies. Twenty-three studies investigated the effectiveness (n = 23) or cost-effectiveness (n = 2) of antimicrobial agents for DFUs. Eight studied intravenous antibiotics, five oral antibiotics, four different topical agents such as dressings, four subcutaneous granulocyte colony stimulating factor (G-CSF), one evaluated oral and topical Ayurvedic preparations and one compared topical sugar versus antibiotics versus standard care. The majority of trials were underpowered and were too dissimilar to be pooled. There was no strong evidence for recommending any particular antimicrobial agent for the prevention of amputation, resolution of infection or ulcer healing. Topical pexiganan cream may be as effective as oral antibiotic treatment with ofloxacin for the resolution of local infection. Ampicillin and sulbactam were less costly than imipenem and cilastatin, a growth factor (G-CSF) was less costly than standard care and cadexomer iodine dressings may be less costly than daily dressings. A decision analytic model was derived for two groups of people, those for whom diagnostic testing would inform treatment--people with ulcers which do not appear infected but whose ulcer is not progressing despite optimal concurrent treatment--and those in whom a first course of antibiotics (prescribed empirically) have failed. There was insufficient information from the systematic reviews or interviews with experts to populate the model with transition probabilities for the sensitivity and specificity of diagnosis of infection in DFUs. Similarly, there was insufficient information on the probabilities of healing, amputation or death in the intervention studies for the two populations of interest. Therefore, we were unable to run the model to inform the most effective diagnostic and treatment strategy.

CONCLUSIONS

The available evidence is too weak to be able to draw reliable implications for practice. This means that, in terms of diagnosis, infection in DFUs cannot be reliably identified using clinical assessment. This has implications for determining which patients need formal diagnostic testing for infection, on whether empirical treatment with antibiotics (before the results of diagnostic tests are available) leads to better outcomes, and on identifying the optimal methods of diagnostic testing. With respect to treatment, it is not known whether treatment with systemic or local antibiotics leads to better outcomes or whether any particular agent is more effective. Limited evidence suggests that both G-CSF and cadexomer iodine dressings may be less expensive than 'standard' care, that ampicillin/sulbactam may be less costly than imipenem/cilastatin, and that an unlicensed cream (pexiganan) may be as effective as oral ofloxacin. Further research is needed to ascertain the characteristics of infection in people with DFUs that influence healing and amputation outcomes, to determine whether detecting infection prior to treatment offers any benefit over empirical therapy, and to establish the most effective and cost-effective methods for detecting infection, as well as the relative effectiveness and cost-effectiveness of antimicrobial interventions for DFU infection.

Systematic review of antimicrobial treatments for diabetic foot ulcers

BACKGROUND

Foot ulcers in diabetes are associated with increased mortality, illness and reduced quality of life. Ulcer infection impairs healing and antimicrobial interventions may cure infection, aid healing and reduce amputation rates.

OBJECTIVES

To systematically review the evidence for antimicrobial interventions for foot ulcers in diabetes.

METHODS

We searched 16 databases, 11 Internet sites, three books, conference proceedings, a journal and bibliographies in November 2002. We included randomized controlled trials (RCTs) or controlled clinical trials (CCTs).

RESULTS

Twenty-three studies investigated the effectiveness or cost-effectiveness of antimicrobial agents: intravenous antibiotics (n = 8); oral antibiotics (n = 5); topical antimicrobials (n = 4); subcutaneous granulocyte-colony stimulating factor (G-CSF) (n = 4); Ayurvedic preparations (n = 1): and sugar vs. antibiotics vs. standard care (n = 1). The trials were small and too dissimilar to be pooled. There is no strong evidence for any particular antimicrobial agent for the prevention of amputation, resolution of infection, or ulcer healing. Pexiganan cream may be as effective as oral ofloxacin for resolution of infection. Ampicillin and sulbactam cost less than imipenem/cilastatin, G-CSF cost less than standard care and cadexomer iodine dressings may cost less than daily dressings.

CONCLUSIONS

The evidence is too weak to recommend any particular antimicrobial agent. Large studies are needed of the effectiveness and cost-effectiveness of antimicrobial interventions.

Systematic review of methods to diagnose infection in foot ulcers in diabetes

AIM

To undertake a systematic review of the diagnostic performance of clinical examination, sample acquisition and sample analysis in infected foot ulcers in diabetes.

METHODS

Nineteen electronic databases plus other sources were searched. To be included, studies had to fulfil the following criteria: (i) compare a method of clinical assessment, sample collection or sample analysis with a reference standard; (ii) recruit diabetic individuals with foot ulcers; (ii) present 2 x 2 diagnostic data. Studies were critically appraised using a 12-item checklist.

RESULTS

Three eligible studies were identified, one each on clinical examination, sample collection and sample analysis. For all three, study groups were heterogeneous with respect to wound type and a small proportion of participants had foot ulcers due to diabetes. No studies identified an optimum reference standard. Other methodological problems included non-blind interpretation of tests and the time lag between index and reference tests. Individual signs or symptoms of infection did not prove to be useful tests when assessed against punch biopsy as the reference standard. The wound swab did not perform well when assessed against tissue biopsy. Semiquantitative analysis of wound swab might be a useful alternative to quantitative analysis. The limitations of these findings and their impact on recommendations from relevant clinical guidelines are discussed.

CONCLUSION

Given the importance of this topic, it is surprising that only three eligible studies were identified. It was not possible to describe the optimal methods of diagnosing infection in diabetic patients with foot ulceration from the evidence identified in this systematic review.

An exploration of the use of ultrasound in the treatment of chronic venous leg ulcers

A nurse-led multicentre randomised controlled trial will compare the clinical effectiveness of weekly ultrasound combined with standard care in the treatment of 'hard-to-heal' venous leg ulcers. Recruitment started last autumn.

Skin grafting for venous leg ulcers

BACKGROUND

Venous leg ulceration is a common and disabling condition which often recurs. It affects up to one in 100 adults at some time. The usual treatments are simple dressings and compression bandages or stockings. Unfortunately, in some cases this treatment is unsuccessful, with ulcers remaining open for months or years. Sometimes skin grafts are used to stimulate healing. These skin grafts may be taken from the patient's own uninjured skin, may be grown from the patient's skin cells into a dressing (autografts), or applied as a sheet of bioengineered skin grown from donor cells (allograft). Preserved skin from other animals, such as pigs, has also been used; these grafts are known as xerografts.

OBJECTIVES

To assess the effect of skin grafts for treating venous leg ulcers.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (June 2004) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2004).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of skin grafts in the treatment of venous leg ulcers.

DATA COLLECTION AND ANALYSIS

Two reviewers independently undertook data extraction and assessment of study quality.

MAIN RESULTS

Nine trials of skin grafts for venous leg ulcers were identified, involving 579 participants. The trials were generally of poor methodological quality. In eight trials participants also received compression bandaging. Two trials (98 participants) evaluated split thickness autografts (one against a dressing and one against a xerograft), four trials (119 participants) evaluated cultured keratinocyte grafts (3 allografts and 1 autograft) , two compared tissue engineered skin (bilayer artificial skin) with a dressing (345 participants), and one compared it with a split thickness skin graft (7 participants, 13 ulcers). The trials comparing bilayer artificial skin with a dressing reported a significantly higher proportion of ulcers healing with artificial skin. There was not enough evidence from the other trials to determine whether other types of skin grafting increased the healing of venous ulcers.

AUTHORS' CONCLUSIONS

There is evidence that a bilayer artificial skin, used in conjunction with compression bandaging, increases the chance of healing a venous ulcer compared with compression and a simple dressing. Further research is needed to assess whether other forms of skin grafts increase ulcer healing.

VenUS I: a randomised controlled trial of two types of bandage for treating venous leg ulcers

OBJECTIVES

To compare the clinical and cost-effectiveness of two different compression bandages for the healing of venous leg ulcers.

DESIGN

A pragmatic, randomised controlled trial with an economic evaluation.

SETTING

Community, district nurse-led services; community leg ulcer clinics; hospital leg ulcer clinics with community outreach. A range of urban and rural settings in England and Scotland.

PARTICIPANTS

Patients with a venous leg ulcer of at least 1-week's duration, at least 1 cm in length or width and an ankle:brachial pressure index of at least 0.8.

INTERVENTIONS

The four-layer bandage (4LB) (which is multilayer elastic compression) compared with the short-stretch bandage (SSB) (multilayer, inelastic compression).

MAIN OUTCOME MEASURES

The primary end-point was complete healing of all the ulcers on the trial leg. Secondary outcomes were the proportion of patients healed at 12 and 24 weeks, rate of recurrence, costs of leg ulcer treatment and quality of life.

RESULTS

Between April 1999 and December 2000 the trial recruited 387 people aged from 23 to 97 years at trial entry. The majority of patients in this trial (82%; 316/387) had a reference ulcer of area </=10 cm(2). To test the difference over time of Kaplan--Meier curves for the two bandage groups, the distribution of the cumulative times to healing of individuals in the two trial groups was compared using the log-rank test. The difference in the distribution of cumulative healing times between the individuals in the two groups was not statistically significant at the 5% level. Adjusting for the effects of variables which may influence healing (centre, baseline ulcer area, duration, episodes, ankle mobility, weight) in a Cox proportional hazards model, a statistically significant treatment effect in favour of the 4LB was identified. At any point in time, the probability of healing for individuals in the SSB treatment arm is significantly lower than that for people treated with the 4LB. Our base case economic analysis showed that the 4LB is the dominant strategy, that is, it is associated with a greater health benefit and lower costs than the SSB, although the differences are not statistically significant. This result is explained largely by the greater number of community nurse visits required by participants in the short-stretch arm.

CONCLUSIONS

The 4LB, which is currently the UK standard compression bandage for people with venous leg ulcers, was more clinically and cost-effective than the SSB. The bandage costs were less important than the costs of treatment visits, and patients in SSBs required more treatment overall. Generally, this trial supports the use of the 4LB in preference to the SSB. Recommendations for future research include: exploration of the relationship between bandager skill, application technique and ulcer healing; the relative cost-effectiveness of community leg ulcer clinics; and the study of nurse decision-making in venous ulcer management.

Economic analysis of VenUS I, a randomized trial of two bandages for treating venous leg ulcers

BACKGROUND

The study investigated the cost-effectiveness of four-layer and short-stretch compression bandages for treating venous leg ulcers.

METHODS

Cost-effectiveness and cost-utility analyses were performed using patient-level data collected alongside the VenUS I leg ulcer study. The perspective for the economic analysis was that of the UK National Health Service (NHS) and Personal Social Service. The time horizon for the analysis was 1 year after recruitment. Health benefit was measured as differences in ulcer-free days and quality-adjusted life years (QALYs).

RESULTS

The mean healing time for ulcers treated with four-layer bandages was 10.9 (95 per cent confidence interval (c.i.) -6.8 to 29.1) days less than that for ulcers treated with short-stretch bandages. Mean average difference in QALYs between compression systems was -0.02 (95 per cent c.i. -0.08 to 0.04). The four-layer bandage cost a mean of pound 227.32 (95 per cent c.i. pound 16.53 to pound 448 .30) less per patient per year than the short-stretch bandage.

CONCLUSION

On average, four-layer bandaging was associated with greater health benefits and lower costs than short-stretch bandaging.

Randomized clinical trial of four-layer and short-stretch compression bandages for venous leg ulcers (VenUS I)

BACKGROUND

A randomized clinical trial was undertaken to determine the relative effectiveness of four-layer and short-stretch bandaging for venous ulceration.

METHODS

A total of 387 adults with a venous ulcer, who were receiving leg ulcer treatment either in primary care or as a hospital outpatient, were recruited to this parallel-group open study and randomized to either four-layer or short-stretch bandages. Follow-up continued until the patient's reference leg was ulcer free or for a minimum of 12 months. The primary endpoint was time to complete healing of all ulcers on the reference leg. Secondary outcomes included proportion of ulcers healed, health-related quality of life, withdrawals and adverse events. Analysis was by intention to treat.

RESULTS

Unadjusted analysis identified no statistically significant difference in median time to healing: 92 days for four-layer and 126 days for short-stretch bandages. However, when prognostic factors were included in a Cox proportional hazards regression model, ulcers treated with the short-stretch bandage had a lower probability of healing than those treated with the four-layer bandage: hazard ratio 0.72 (95 per cent confidence interval 0.57 to 0.91). More adverse events and withdrawals were reported with the short-stretch bandage.

CONCLUSION

Venous leg ulcers treated using a four-layer bandage healed more quickly than those treated with a short-stretch bandage.

Dressings and topical agents for arterial leg ulcers

BACKGROUND

It is estimated that people in industrialised countries have a 1% chance of suffering from a leg ulcer at some time in their life. The majority of leg ulcers are associated with circulation problems; poor blood return in the veins causes venous ulcers (around 70% of ulcers) and poor blood supply to the legs causes arterial ulcers (around 25% of ulcers). Treatment of arterial leg ulcers is directed towards correcting the poor arterial blood supply, for example, by surgically correcting arterial blockages, and by supporting ulcer healing using topical agents (medicines in cream/ointment) and wound dressings. There are a large number of topical agents and wound dressings available and it is unclear what impact these have on ulcer healing.

OBJECTIVES

To determine whether topical agents and wound dressings affect the rate of healing in arterial ulcers. To compare healing rates, costs and patient-centred outcomes between wound dressings and topical agents.

SEARCH STRATEGY

Publications describing (or potentially describing) randomised controlled trials (RCTs), or controlled clinical trials (CCTs) of dressings and topical agents for arterial leg ulcers were sought through the Specialised Trials Registers of the Cochrane Wounds Group (last searched January 2002) and the Cochrane Peripheral Vascular Diseases Group (last searched April 2002).

SELECTION CRITERIA

RCTs or CCTs (trials with non-randomised concurrent comparison groups) were eligible for inclusion. The participants had to have ulcers that were described as arterial, and the time to healing, proportion completely healed, or rate of reduction in ulcer area had to be reported. All wound dressings and topical agents were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

Information on the participants' characteristics, the interventions, and outcomes, as well as data on the trial methods, such as blinding of patients and clinicians, and allocation concealment were extracted using a standardised data extraction form.

MAIN RESULTS

One trial met the inclusion criteria. This small trial compared ketanserin ointment with vehicle alone, changed twice a day. The trial was too small and for too short a follow-up period to be able to determine whether there was any difference in healing rates.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to determine whether the choice of topical agent or dressing affects the healing of arterial leg ulcers. Inadequate description of the people in the one included trial means that the results cannot be easily applied to other clinical populations.

Topical agents or dressings for pain in venous leg ulcers

BACKGROUND

Venous leg ulcers affect up to 1 per cent of people at some time in their life. These ulcers are often painful and some clinicians choose dressings and topical treatments (analgesia/ local anaesthetic) to reduce the pain both during and between dressing changes.

OBJECTIVES

To assess the effectiveness of dressings, local anaesthetics or topical analgesia for pain relief in venous leg ulceration.

SEARCH STRATEGY

Cochrane Wounds Group Register and the Cochrane Collaboration Field in Complementary Medicine were searched in June 2002. Cochrane Pain Palliative and Supportive Care Group and Cochrane Wounds Group strategy were combined and used.

SELECTION CRITERIA

All randomised controlled trials which evaluated local interventions used to relieve venous leg ulcer pain were considered. Pain was defined as either persistent pain or pain at dressing changes or debridement.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion was confirmed by two reviewers who independently assessed the potential trials. Details of eligible studies were summarised using a data extraction sheet which was checked by the second reviewer.

MAIN RESULTS

No trials evaluating interventions for persistent pain were identified for the initial review in 1999 nor the update in 2002. Three trials were included in the 1999 review comparing a eutectic mixture of local anaesthetic (EMLA) versus placebo for pain at debridement. In 2002 a further 3 trials were available (6 trials in total with 317 patients). The studies were considered sufficiently similar to pool and meta analysis found a statistically significant reduction in debridement pain scores with EMLA 5% cream. EMLA was associated with a reduction in pain scores (measured on a 100 mm scale) of 20.6 mm (95% Confidence Interval 29.11-12.19). One small trial measured healing as an outcome and found no difference in numbers of ulcers healed at the end of the study.

REVIEWER'S CONCLUSIONS

EMLA provides effective pain relief for venous leg ulcer debridement however, the effect of the product on ulcer healing is unknown. Research is required to determine the impact of debridement and of EMLA on ulcer healing. There were no trials addressing the treatment of persistent pain (between and at dressing changes) and further research is warranted.

Use of compression hosiery in venous leg ulceration

Venous leg ulceration is a common problem in older people that adversely affects their quality of life. It is also a major cause of morbidity for many patients in hospital and community settings. Patients experience considerable pain and distress as a result of this condition and annual costs to the NHS are high. However, good nursing management and the correct use of compression therapy can lead to faster healing rates (Effective Health Care 1997), and reduced nursing time. This article discusses the use of compression hosiery in the prevention and treatment of venous leg ulcers.

Measurement of body fat using leg to leg bioimpedance

AIMS

(1) To validate a leg to leg bioimpedance analysis (BIA) device in the measurement of body composition in children by assessment of its agreement with dual energy x ray absorptiometry (DXA) and its repeatability. (2) To establish a reference range of percentage body fat in Hong Kong Chinese children.

METHODS

Sequential BIA and DXA methods were used to determine body composition in 49 children aged 7-18 years; agreement between the two methods was calculated. Repeatability for the BIA method was established from duplicate measurements. Body composition was then determined by BIA in 1139 girls and 1243 boys aged 7-16 years, who were randomly sampled in eight local primary and secondary schools to establish reference ranges.

RESULTS

The 95% limits of agreement between BIA and DXA methods were considered acceptable (-3.3 kg to -0.5 kg fat mass and -3.9 to 0.6% body fat). The percentage body fat increased with increasing age. Compared to the 1993 Hong Kong growth survey, these children had higher body mass index. Mean (SD) percentage body fat at 7 years of age was 17.2% (4.4%) and 14.0% (3.4%) respectively for boys and girls, which increased to 19.3% (4.8%) and 27.8% (6.3%) at age 16.

CONCLUSION

Leg to leg BIA is a valid alternative method to DXA for the measurement of body fat. Provisional reference ranges for percentage body fat for Hong Kong Chinese children aged 7-16 years are provided.

A 10-kDa structural protein of porcine reproductive and respiratory syndrome virus encoded by ORF2b

The major structural proteins of porcine reproductive and respiratory syndrome virus (PRRSV) are derived from ORFs 5, 6, and 7. Western blots of sucrose gradient-purified virions and PRRSV-infected MARC-145 cells, probed with immune pig serum, showed the presence of an additional 10-kDa protein. Nucleotide sequence analysis of North American PRRSV isolate SDSU-23983 revealed a small ORF within ORF2, named ORF2b, which, when translated, produced a 73-amino-acid nonglycosylated protein. Recombinant 2b protein expressed by a baculovirus clone, AcVR2, comigrated with the 10-kDa virus-associated protein. The loss of 10-kDa protein immunoreactivity after absorption of immune sera with lysates from AcVR2-infected insect cells demonstrated that the 2b and 10-kDa proteins are immunologically similar. Immunoblots were also used for the detection of anti-2b activity in serum samples from experimentally infected adult pigs. Antibodies against PRRSV were apparent by 14 days postinfection, followed by anti-2b activity and serum neutralizing activity. The putative ORF2b start codon is only 6 nucleotides downstream of the adenine of the ORF2a start codon. The expression of ORF2a and 2b as enhanced green fluorescent fusion proteins showed that both proteins were translated; however, the ORF2b was preferentially expressed. These results suggest that the 2b protein is virion associated and the principal product of ORF2.

International Child Care Practices Study: infant sleep position and parental smoking

The International Child Care Practices Study (ICCPS) collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the key sudden infant death syndrome (SIDS) risk factors of infant sleep position and parental smoking.

METHODS

Using a standardised protocol, parents of infants were surveyed at birth by interview, and at 3 months of age mainly by postal questionnaire. Data entry and descriptive analysis were undertaken with Epi Info. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey.

RESULTS

Birth interview data were available for 5488 individual families, and 4656 (85%) returned questionnaires at 3 months. Overall, 52.5% (95% CI, 43.5-61.3) of infants were placed in the supine or back sleep position, 37.8% (95% CI, 30.6-45.7) in the side position and 13% (95% CI, 9.3-17.9) in the prone or front position. The prevalence of supine sleeping ranged from 14% (Santiago, Chile) to 89% (Tokyo/Yokohama, Japan). The prevalence of reported smoking was between 0% and 34% for mothers and 10% and 64% for fathers. In samples from Western countries, there was a trend for rates of maternal smoking to be similar to paternal smoking, whereas in other samples, low rates of maternal smoking contrasted with high rates of paternal smoking.

CONCLUSIONS

These data highlight considerable variations and interesting patterns in the prevalence of these two important SIDS risk factors in these diverse samples. Impressive differences in rates of smoking within and between these communities may reflect different stages of the inevitable progression of the smoking epidemic, but may also provide some encouragement that reduction in smoking rates, in both mothers and fathers, is possible.

Systematic reviews of wound care management: (5) beds; (6) compression; (7) laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy

BACKGROUND

Chronic wounds such as leg ulcers, diabetic foot ulcers and pressure sores are common in both acute and community healthcare settings. The prevention and treatment of these wounds involves many strategies: pressure-relieving beds, mattresses and cushions are universally used as measures for the prevention and treatment of pressure sores; compression therapy in a variety of forms is widely used for venous leg ulcer prevention and treatment; and a whole range of therapies involving laser, ultrasound and electricity is also applied to chronic wounds. This report covers the final three reviews from a series of seven.

AIMS

To assess the clinical effectiveness and cost- effectiveness of: (1) pressure-relieving beds, mattresses and cushions for pressure sore prevention and treatment; (2) compression therapy for the prevention and treatment of leg ulcers; (3) low-level laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy for the treatment of chronic wounds. METHODS - DATA SOURCES: Nineteen electronic databases, including MEDLINE, CINAHL, EMBASE and the Cochrane Controlled Trials Register (CENTRAL), were searched. Relevant journals, conference proceedings and bibliographies of retrieved papers were handsearched. An expert panel was also consulted.

METHODS - STUDY SELECTION

Randomised controlled trials (RCTs) which evaluated these interventions were eligible for inclusion in this review if they used objective measures of outcome such as wound incidence or healing rates. RESULTS - BEDS, MATTRESSES AND CUSHIONS FOR PRESSURE SORE PREVENTION AND TREATMENT: A total of 45 RCTs were identified, of which 40 compared different mattresses, mattress overlays and beds. Only two trials evaluated cushions, one evaluated the use of sheepskins, and two looked at turning beds/kinetic therapy. RESULTS - COMPRESSION FOR LEG ULCERS: A total of 24 trials reporting 26 comparisons were included (two of prevention and 24 of treatment strategies). RESULTS - LOW-LEVEL LASER THERAPY, THERAPEUTIC ULTRASOUND, ELECTROTHERAPY AND ELECTROMAGNETIC THERAPY: Four RCTs of laser (for venous leg ulcers), 10 of therapeutic ultrasound (for pressure sores and venous leg ulcers), 12 of electrotherapy (for ischaemic and diabetic ulcers, and chronic wounds generally) and five of electromagnetic therapy (for venous leg ulcers and pressure sores) were included. Studies were generally small, and of poor methodological quality. CONCLUSIONS (1) Foam alternatives to the standard hospital foam mattress can reduce the incidence of pressure sores in people at risk, as can pressure-relieving overlays on the operating table. One study suggests that air-fluidised therapy may increase pressure sore healing rates. (2) Compression is more effective in healing venous leg ulcers than is no compression, and multi-layered high compression is more effective than single-layer compression. High-compression hosiery was more effective than moderate compression in preventing ulcer recurrence. (3) There is generally insufficient reliable evidence to draw conclusions about the contribution of laser therapy, therapeutic ultrasound, electrotherapy and electromagnetic therapy to chronic wound healing.

Postnatal iron status of Hong Kong Chinese women in a longitudinal study of maternal nutrition

OBJECTIVE

To report postnatal iron nutritional status of Hong Kong Chinese women during the first 6 months postpartum.

DESIGN AND SUBJECTS

A longitudinal study examining postnatal calcium and iron status of Hong Kong Chinese breastfeeding and formula-feeding women was conducted during 1998. Postpartum women aged 20-40 y, with no bone or blood disorders were recruited and interviewed at 0 (baseline), 2, 6 weeks, 3 and 6 months postpartum. Dietary intake was assessed by a 3 day dietary record and cross checked by a 24 h recall. Complete blood count and serum ferritin level were measured to assess anaemia and iron status. In this report, subjects were divided into an anaemic group (haemoglobin level < 10 g/dl) and a non-anaemic group (haemoglobin level > or = 10 g/dl) according to baseline haemoglobin levels.

RESULTS

At baseline, 13/47 (27.7%) subjects were anaemic. Two of these 13 anaemic subjects were still anaemic at 3 and 6 months postpartum. Anaemic subjects showed significantly (P < 0.01) greater amounts of blood loss and a higher rate of primary postpartum haemorrhage than the non-anaemic subjects. Daily food intake and dietary nutrient intake did not differ significantly between the two groups. During the first 6 weeks postpartum, subjects in both groups consumed more poultry and egg, and comparable amounts of meat, compared with women in the Hong Kong general population. Iron and vitamin C intakes for the majority of subjects reached 60% of the US Recommended Daily Allowances. Regression analysis suggested that the rate of change in haemoglobin level in the first 6 weeks postpartum was positively correlated with baseline MCV level and serum ferritin level, but negatively correlated with baseline haemoglobin level.

CONCLUSIONS

Blood loss at delivery is an important factor for postpartum anaemia. Postnatal recovery of iron status of this group of women appeared to be more related to physiological factors than to dietary factors. The role of diet as well as other physiological changes in postpartum women requires further investigation. Finding ways to minimise blood loss at delivery could be the most practical strategy to reduce the rate of postpartum anaemia.

SPONSORSHIP

CSM was supported by a research studentship from the Research Grants Council, Hong Kong.

International Child Care Practices Study: infant sleeping environment

BACKGROUND

The International Child Care Practices Study (ICCPS) has collected descriptive data from 21 centres in 17 countries. In this report, data are presented on the infant sleeping environment with the main focus being sudden infant death syndrome (SIDS) risk factors (bedsharing and infant using a pillow) and protective factors (infant sharing a room with adult) that are not yet well established in the literature.

METHODS

Using a standardised protocol, parents of infants were surveyed at birth by interview and at 3 months of age mainly by postal questionnaire. Centres were grouped according to geographic location. Also indicated was the level of SIDS awareness in the community, i.e. whether any campaigns or messages to "reduce the risks of SIDS" were available at the time of the survey.

RESULTS

Birth interview data were available for 5488 individual families and 4656 (85%) returned questionnaires at 3 months. Rates of bedsharing varied considerably (2-88%) and it appeared to be more common in the samples with a lower awareness of SIDS, but not necessarily a high SIDS rate. Countries with higher rates of bedsharing appeared to have a greater proportion of infants bedsharing for a longer duration (>5 h). Rates of room sharing varied (58-100%) with some of the lowest rates noted in centres with a higher awareness of SIDS. Rates of pillow use ranged from 4% to 95%.

CONCLUSIONS

It is likely that methods of bedsharing differ cross-culturally, and although further details were sought on different bedsharing practices, it was not possible to build up a composite picture of "typical" bedsharing practices in these different communities. These data highlight interesting patterns in child care in these diverse populations. Although these results should not be used to imply that any particular child care practice either increases or decreases the risk of SIDS, these findings should help to inject caution into the process of developing SIDS prevention campaigns for non-Western cultures.

Detection and duration of porcine reproductive and respiratory syndrome virus in semen, serum, peripheral blood mononuclear cells, and tissues from Yorkshire, Hampshire, and Landrace boars

Because transmission of porcine reproductive and respiratory syndrome virus (PRRSV) can occur through boar semen, it is important to identify persistently infected boars. However, even for boars given the same PRRSV strain and dose, variability in the duration of viral shedding in semen has been observed, suggesting that host factors are involved in PRRSV persistence. To determine whether there are host genetic factors, particularly litter and breed differences related to the persistence of PRRSV, 3 litters from 3 purebred swine breeds were used for this study. It was also determined whether PRRSV could be detected for a longer period of time in serum, semen, or peripheral blood mononuclear cells (PBMC) and if PRRSV could still be detected in tissues after these antemortem specimens were PRRSV negative for a minimum of 2-3 weeks. Three Hampshire, 3 Yorkshire, and 2 Landrace PRRSV-naive boars were obtained and inoculated intranasally with a wild-type PRRSV isolate (SD-23983). All boars within each breed were from the same litter, and litters were within 9 days of age. Serum and PBMC were collected twice weekly from each boar and analyzed for the presence of PRRSV by virus isolation and the polymerase chain reaction (PCR). Serum was also used to obtain virus neutralization titers and enzyme-linked immunosorbent assay S/P values. Semen was collected twice weekly from 7 of 8 boars and analyzed by PCR. After all specimens were PRRSV negative for a minimum of 2-3 weeks, each boar was euthanized, and 21 tissues plus saliva, serum, feces, and urine were collected. All postmortem specimens were evaluated by virus isolation. Specimens that were PRRSV negative by virus isolation were then evaluated by PCR. The mean number of days (+/-SD) for the duration of PRRSV shedding in semen was 51+/-26.9 days, 7.5+/-4.9 days, and 28.3+/-17.5 days for Landrace, Yorkshire, and Hampshire boars, respectively. Because of small sample sizes and large SDs, the differences in duration of PRRSV shedding in semen between breeds were not considered significant. However, the trend suggested that Yorkshire boars were more resistant to PRRSV shedding in semen than were Landrace boars, requiring further investigation using a larger numbers of boars. PRRSV was detected for a longer period in semen than in serum or PBMC in 4 of 7 boars. Viremia could be detected for a longer period in serum than in PBMC in 6 of 8 boars. After a minimum of 2-3 weeks of PRRSV-negative serum, semen, and PBMC, PRRSV could still be detected in the tonsil of 3 of 8 boars by virus isolation, indicating that boars still harbor PRRSV within the tonsil even though antemortem specimens are PRRSV negative.

Preliminary results of a pilot program on depression in patients with congestive heart failure

While the sample size is too small to warrant conclusions, these preliminary results suggest that assessment of depression would be worthwhile for patients diagnosed with congestive heart failure. 32 out of 54 patients with congestive heart failure scored positive for depression. When psychiatric treatment was given, there was a decrease in depressive symptoms for four of the six patients at the 6-mo, retest. A decrease in depressive symptoms was found for two of the six untreated patients, and the remaining four patients had worse scores on the Zung Depression Inventory. Primary care physicians, who typically meet with such patients regularly, are encouraged to screen for depression, as their clinical assessments in this study were associated with scores on the Zung Depression Inventory. These observations support a full scale investigation with a much larger sample size and a requisite medical cost comparison.

Intermittent pneumatic compression for treating venous leg ulcers

BACKGROUND

Intermittent pneumatic compression (IPC) is a mechanical method of delivering compression to swollen limbs. This technique has been used to treat venous leg ulcers and limb swelling due to lymphoedema. The effectiveness of IPC, and the appropriate duration and frequency of IPC therapy are unknown as are the differences between various types of IPC. This review analyses the evidence for the effectiveness of IPC as a treatment for venous leg ulcers.

OBJECTIVES

To determine whether IPC increases the healing of venous leg ulcers. To determine the effects of IPC on health related quality of life of venous leg ulcer patients.

SEARCH STRATEGY

The Cochrane Wound Group Trials Register was searched for RCTs of intermittent pneumatic compression in February 2001. Journals and relevant conference proceedings were searched by hand. Companies were also contacted for relevant unpublished data or ongoing studies.

SELECTION CRITERIA

Randomised controlled studies either comparing IPC with control (sham IPC or no IPC) or comparisons between IPC treatment regimens, in venous ulcer management were included.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of study quality were undertaken by two reviewers independently.

MAIN RESULTS

Four randomised controlled trials were identified. One small trial (45 people) found increased ulcer healing with IPC plus compression than with compression alone (relative risk for healing 11.4, 95% Confidence Interval 1.6 to 82). Two small trials with a total of 75 people found no evidence of a benefit for IPC plus compression compared with compression alone. One small trial (16 people) found no difference between IPC (without additional compression) and compression bandages alone.

REVIEWER'S CONCLUSIONS

Further trials are required to determine whether IPC increases the healing of venous leg ulcers.

Physician attitudes toward and prevalence of the hospitalist model of care: results of a national survey

PURPOSE

We sought to determine the availability and utilization of, as well as physician attitudes toward, the hospitalist model in the United States.

SUBJECTS AND METHODS

Using a telephone survey, we asked physicians who were board certified in internal medicine about their inpatient practice arrangements, the availability of hospitalist services, and their attitudes toward the hospitalist model. All physicians were generalists in active clinical practice. Using multivariable methods, we determined factors associated with attitudes toward the hospitalist model.

RESULTS

We were able to contact 787 of 2,829 physicians who were randomly selected from a national list of board-certified internists, of whom 400 agreed to participate. Most respondents were familiar with the term "hospitalist" and had hospitalist services available in their community, and 28% used hospitalists for their inpatients. Few (2%) reported the presence of the "mandatory" hospitalist model. Physicians reported that the model was more commonly available in Western states (84% vs. 55% to 63% in other regions, P<0.0001). Seventy-three percent thought hospitalist systems would reduce continuity of care. Only 28% thought that patients would prefer care from an inpatient specialist, but 51% thought patients might get better care, and 47% thought patients might get more cost-effective care in a hospitalist system. In multivariable models, physicians who were in solo practice, those in specialties with more inpatient practice, and those who had more patients hospitalized each month responded more negatively about the model, whereas those with hospitalists in their community were more positive.

CONCLUSIONS

Although agreeing that quality of care and efficiency might be improved, physicians were concerned about patient-doctor relationships and patient satisfaction in a hospitalist model. Future studies should determine the effect of the hospitalist model on these outcomes.

Increased density of gutta-percha using a controlled heat instrument with lateral condensation

The purpose of this study was to compare quantitatively the density of standard cold lateral gutta-percha condensation and warm lateral gutta-percha condensation using the System B heating instrument in a low-heat warm lateral condensation technique in an artificial root canal in vitro. Thirty-degree simulated root canals in 30 transparent acrylic blocks were instrumented using Gates-Glidden burs and Quantec (NT Company, Chattanooga, TN) rotary files. The canals were then obturated with gutta-percha using standard cold lateral condensation without sealer. Warm lateral condensation without sealer using the System B instrument at 101 degrees C was then performed on the same 30 canals. A second treatment of warm lateral condensation was then applied to these same canals. The blocks were weighed after the initial canal preparation and after each obturation treatment. Results showed warm lateral condensation of gutta-percha using the System B resulted in a significant increase in density by weight when compared with standard cold lateral condensation. A 23.97% increase in weight was realized after the first heat application, compared with standard lateral condensation. A second heat application produced an additional 2.59% increase in weight over that produced by the first heat application. Data were analyzed using a t test for repeated measures. Both increases were statistically significant (p < 0.001). Warm lateral condensation using the System B instrument results in denser gutta-percha fills by weight when compared with standard cold lateral condensation.

Measurement of immunoglobulin G, A and M concentrations in boar seminal plasma

How the immune system relates to the boar reproductive tract is not well defined. This is an important area of study because disease-causing agents may be transmitted through boar semen. We have previously identified porcine reproductive and respiratory syndrome virus (PRRSV) in boar semen and wanted to identify PRRSV-specific antibodies within seminal plasma. However, literature documenting total immunoglobulin concentration or the predominant immunoglobulin isotype in boar semen was not available. Therefore, we developed a sandwich enzyme-linked immunoassay (ELISA) to quantitate total IgG, IgA and IgM in seminal plasma from 16 healthy, nonvaccinated, adult boars (n = 102 semen samples). In seminal plasma, IgG was the predominant isotype followed by IgA and IgM. Mean levels +/- the standard deviation followed by the 95% confidence interval of IgG, IgA and IgM were 23.2 +/- 14 microg/mL (15.5 to 31.0), 4.8 +/- 2.5 microg/mL (3.5 to 6.2) and 3.7 +/- 1.7 microg/mL (2.7 to 4.7), respectively. These concentrations of immunoglobulins in seminal plasma were considerably lower than in other swine secretions, which might allow for the survival of infectious agents in boar semen.

The synthesis and SAR of rhodanines as novel class C beta-lactamase inhibitors

Beta-lactam antibiotics such as the cephalosporins and penicillins have diminished clinical effectiveness due to the hydrolytic activity of diverse beta-lactamases, especially those in molecular classes A and C. A structure activity relationship (SAR) study of a high-throughput screening lead resulted in the discovery of a potent and selective non-beta-lactam inhibitor of class C beta-lactamases.