Insertion of a nasogastric tube under direct vision.
Explore the source record for details and available documents.
Bronchoscopy↗
Biomedical subjects
A P Jones
Publications and source records attributed to A P Jones.
Nebulised hypertonic saline for cystic fibrosis.
BACKGROUND: Lung disease in cystic fibrosis is characterised by impaired mucociliary clearance. Hypertonic saline has been shown to enhance mucociliary clearance in vitro and this may act to lessen the destructive inflammatory process in the airways. OBJECTIVES: To investigate the effects of treatment with nebulised hypertonic saline on people with cystic fibrosis compared to placebo and or other treatments that enhance mucociliary clearance. SEARCH STRATEGY: 'We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register, comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. Most recent search of the Trials Register: September 2004. SELECTION CRITERIA: All controlled trials assessing the effect of hypertonic saline compared to placebo or other mucolytic therapy, for any duration or dose regimen in people with cystic fibrosis of any age or severity. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed all identified trials and all data collected. Trial quality was assessed along with allocation concealment. MAIN RESULTS: Fourteen controlled trials were identified. Nine trials met the inclusion criteria involving 235 participants with an age range of 6 years to 46 years. Two short-term trials of immediate effect on mucociliary clearance demonstrated that hypertonic saline increased isotope clearance compared to control. Lung function, measured by improvement in forced expiratory volume at one second (FEV1 litre per minute), was observed in four trials. When 3% to 7% saline was used in a volume of 10 ml twice-a-day, in comparison to placebo, hypertonic saline led to a significant increase in FEV1, weighted mean difference 12.20 (95%CI 4.28 to 20.10). Two further trials compared a similar concentration and volume of hypertonic saline to recombinant deoxyribonuclease. Over a three-week period one trial showed a non-significant difference, mean difference 1.60 (95% CI -7.96 to 11.16). However, in a further trial, after 12 weeks treatment in participants with moderate to severe lung disease, recombinant deoxyribonuclease led to a greater increase in FEV1 than hypertonic saline (5 ml twice-daily), mean difference 8.00 (95%CI 2.00 to 14.00). No serious adverse events were noted. AUTHORS' CONCLUSIONS: Nebulised hypertonic saline improves mucociliary clearance in short-term clinical trials and appears to increase lung function compared to control. In comparison to recombinant deoxyribonuclease it may be less effective at improving lung function after three months. Currently there is insufficient evidence to support the use of hypertonic saline as routine treatment for people with cystic fibrosis.
Administration, Inhalation↗
Manual therapy for asthma.
BACKGROUND: A variety of manual therapies with similar postulated biologic mechanisms of action are commonly used to treat patients with asthma. Manual therapy practitioners are also varied, including physiotherapists, respiratory therapists, chiropractic and osteopathic physicians. A systematic review across disciplines is warranted. OBJECTIVES: To evaluate the evidence for the effects of manual therapies for treatment of patients with bronchial asthma. SEARCH STRATEGY: We searched for trials in computerized general (EMBASE, CINAHL and MEDLINE) and specialized databases (Cochrane Complementary Medicine Field, Cochrane Rehabilitation Field, Index to Chiropractic Literature (ICL), and Manual, Alternative and Natural Therapy (MANTIS)). In addition, we assessed bibliographies from included studies, and contacted authors of known studies for additional information about published and unpublished trials. Date of most recent search: August 2004. SELECTION CRITERIA: Trials were included if they: (1) were randomised; (2) included asthmatic children or adults; (3) examined one or more types of manual therapy; and (4) included clinical outcomes with observation periods of at least two weeks. DATA COLLECTION AND ANALYSIS: All three reviewers independently extracted data and assessed trial quality using a standard form. MAIN RESULTS: From 473 unique citations, 68 full text articles were retrieved and evaluated, which resulted in nine citations to three RCTs (156 patients) suitable for inclusion. Trials could not be pooled statistically because studies that addressed similar interventions used disparate patient groups or outcomes. The methodological quality of one of two trials examining chiropractic manipulation was good and neither trial found significant differences between chiropractic spinal manipulation and a sham manoeuvre on any of the outcomes measured. One small trial compared massage therapy with a relaxation control group and found significant differences in many of the lung function measures obtained. However, this trial had poor reporting characteristics and the data have yet to be confirmed. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the use of manual therapies for patients with asthma. There is a need to conduct adequately-sized RCTs that examine the effects of manual therapies on clinically relevant outcomes. Future trials should maintain observer blinding for outcome assessments, and report on the costs of care and adverse events. Currently, there is insufficient evidence to support or refute the use of manual therapy for patients with asthma.
Adult↗
Drug therapies for reducing gastric acidity in people with cystic fibrosis.
BACKGROUND: Malabsorption of fat and protein contributes to the poor nutritional status in people with cystic fibrosis. Impaired pancreatic function may also result in increased gastric acidity leading in turn to heartburn, peptic ulcers and the impairment of oral pancreatic replacement therapy. The administration of gastric reducing agents has been used as an adjunct to pancreatic enzyme therapy to improve nutritional status, fat malabsorption and gastro-intestinal symptoms in people with cystic fibrosis. It is thus important to establish the current level of evidence regarding potential benefits of drug therapies that reduce gastric acidity in people with cystic fibrosis. OBJECTIVES: To assess the effect of drug therapies for reducing gastric acidity: in improving nutritional status; on symptoms associated with increased gastric acidity; fat absorption; lung function; quality of life and survival; and to determine if any adverse effects are associated with their use. SEARCH STRATEGY: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books and conference proceedings. Most recent search of the Group's register: April 2002. SELECTION CRITERIA: All randomised and quasi-randomised trials involving agents that reduce gastric acidity compared to placebo or a comparator treatment. DATA COLLECTION AND ANALYSIS: Both reviewers independently selected trials and assessed trial quality. MAIN RESULTS: Thirty-six trials were identified from the initial search. Eleven trials with 172 participants were suitable for inclusion. Five trials were limited to children and three trials enrolled only adults. One trial found that drug therapies which reduce gastric acidity improve gastro-intestinal symptoms such as abdominal pain. Five trials reported significant improvement in measures of fat malabsorption. Two trials reported no significant improvement in nutritional status. Only one trial reported measures of respiratory function and one trial reported an adverse effect with prostaglandin E2 analogue misoprostol. No trials have been identified which assess the effectiveness of agents that reduce gastric acidity in improving quality of life, the complications of increased gastric acidity, or survival. REVIEWER'S CONCLUSIONS: Trials have shown limited evidence that the agents which reduce gastric acidity in people with cystic fibrosis are associated with improvement in gastro-intestinal symptoms and fat absorption. Currently, there is insufficient evidence to indicate whether there is an improvement in nutritional status, lung function, quality of life, or survival. We therefore recommend large, multicentre, randomised controlled clinical trials are undertaken to evaluate these interventions.
Cystic Fibrosis↗
Intravenous beta2-agonists for acute asthma in the emergency department.
BACKGROUND: Inhaled beta-agonist therapy is central to the management of acute asthma. The use of intravenous beta-agonist agents may also be beneficial in this setting. OBJECTIVES: To determine the benefit of intravenous (IV) beta2-agonists for severe acute asthma treated in the emergency department. SEARCH STRATEGY: Randomised controlled trials (RCT) were identified using the Cochrane Airways Group Register which is a compilation of systematic searches of MEDLINE, EMBASE, CINAHL, and CENTRAL as well as hand searching of 20 respiratory journals. Bibliographies from included studies and known reviews were also searched. Primary authors and content experts were contacted to identify eligible studies. SELECTION CRITERIA: Only RCTs were considered for inclusion. Studies were included if patients presented to the emergency department with acute asthma and were treated with IV selective or nonselective beta2-agonists versus placebo, inhaled beta2-agonists, or other standard of care. Pulmonary function, vital signs, arterial gasses, adverse effects, and/or clinical success could be reported as outcome measures. Two reviewers independently selected potentially relevant articles and selected articles for inclusion. Methodological quality was independently assessed using two scoring systems and two reviewers. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two reviewers, and confirmed with corresponding authors. Missing data were obtained from authors or calculated from data present in the papers. Trials were combined using a random effects model for odds ratios (OR) or weighted mean differences (WMD) and reported with 95% confidence intervals (95% CI). MAIN RESULTS: From 746 identified references, 55 potentially relevant articles were identified and 15 were included. The trials included 584 patients. Overall, selective IV beta2-agonist use conferred no advantage over the comparator regimes. For example, it was associated with a lower PEFR after 60 mins compared to inhaled beta2-agonist, although the difference was not statistically significant (-24.7 l/min; 95%CI 2.9, -52.3). There was no difference in heart rate (4.5 bpm; 95% CI -4.9, 14.0). In the well performed blinded studies there was no difference in autonomic side effects between treatments (Odds Ratio 2.2 (95%CI 0.9, 5.7). REVIEWER'S CONCLUSIONS: There is no evidence to support the use of IV beta2-agonists in patients with severe acute asthma. These drugs should be given by inhalation. No subgroups were identified in which the IV route should be considered.
Acute Disease↗
1H MR spectroscopy evidence for the varied nature of asymptomatic focal brain lesions in neurofibromatosis type 1.
We present the MRI and 1H MR spectroscopy findings in six patients with neurofibromatosis type 1 (NF1) and asymptomatic focal brain lesions. Variations in imaging appearances were seen, including regression of a previously identified lesion. MR spectra for the lesions and corresponding areas of normal brain show significant differences. The lesions could be separated into two groups, one demonstrating only slight metabolite ratio changes relative to normal brain and the other group showing significant increase in choline and decrease in N-acetyl aspartate. The lesion which regressed fell into the second group. These findings are not in agreement with those previously reported and provide evidence for the varied and possibly transient nature of these asymptomatic lesions. The spectroscopy findings suggest that metabolite changes may be present without visible changes on MRI.
Adolescent↗
A foundation for the risk-based treatment of gasoline-contaminated soils using modified Fenton's reactions.
The relative oxidation of representative aromatic and aliphatic hydrocarbons found in gasoline was evaluated to provide the foundation for risk-based treatment of petroleum-contaminated soils and groundwater using modified Fenton's reagent (catalyzed hydrogen peroxide). Aromatic components of gasoline are considered more hazardous than the aliphatic fractions due to their higher mobility in the subsurface and their higher acute and chronic toxicities. Benzene, toluene, and mixed xylenes (BTX) were selected as aromatic compounds representative of unleaded gasoline, while nonane, decane, and dodecane (NDD) were used as model aliphatic compounds. The effects of hydrogen peroxide (H(2)O(2)) concentration, iron catalyst concentration, and pH on the degree of treatment of the model compounds were investigated using central composite rotatable experimental designs. Oxidation of the aromatic compounds required less iron and less H(2)O(2) than did oxidation of the aliphatic compounds, while proceeding more effectively at near-neutral pH. Greater than 95% of the BTX was treated at near-neutral pH using 2. 5% H(2)O(2) and 12.5 mM iron (III), while only 37% nonane, 7% decane, and 1% dodecane oxidation was achieved under the same conditions. The results show that the more toxic and mobile aromatic fraction was more effectively oxidized using less H(2)O(2) and more economical conditions, including near-neutral pH, compared to the aliphatic fraction. A process design based on treating only the aromatic fraction of petroleum may provide significantly lower costs when using modified Fenton's reagent for the treatment of contaminated soils and groundwater.
Gasoline↗
Bronchopulmonary hygiene physical therapy for chronic obstructive pulmonary disease and bronchiectasis.
BACKGROUND: Bronchopulmonary hygiene physical therapy is a form of chest physical therapy including chest percussion and postural drainage to remove lung secretions. These are applied commonly to patients with both acute and chronic airway diseases. Despite controversies in the literature regarding its efficacy, it remains in use in a variety of clinical settings. The various forms of this therapy are labour intensive and need to be evaluated. OBJECTIVES: The objective of this review was to assess the effects of bronchial hygiene physical therapy in people with chronic obstructive pulmonary disease and bronchiectasis. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register and reference lists of articles up to July 1997. We also wrote to study authors. SELECTION CRITERIA: Randomised trials in which postural drainage, chest percussion, vibration, chest shaking, directed coughing or forced exhalation technique was compared to other drainage or breathing techniques, placebo or no treatment. DATA COLLECTION AND ANALYSIS: Two reviewers applied the inclusion and exclusion criteria on masked publications independently. They assessed the trial quality independently. Only data from the first arm of crossover trials were included. MAIN RESULTS: The seven included trials involved six comparisons and a total of 126 people. The trials were small and not generally of high quality. The results could not be combined as trials addressed different patient groups and outcomes. In most comparisons, bronchial hygiene physical therapy produced no significant effects on pulmonary function, apart from clearing sputum in chronic obstructive pulmonary disease and in bronchiectasis. REVIEWER'S CONCLUSIONS: There is not enough evidence to support or refute the use of bronchial hygiene physical therapy in people with chronic obstructive pulmonary disease and bronchiectasis.
Bronchiectasis↗
Manual therapy for asthma.
BACKGROUND: A variety of manual therapies with similar postulated biologic mechanisms of action are commonly used to treat patients with asthma. Manual therapy practitioners are also varied, including physiotherapists, respiratory therapists, chiropractic and osteopathic physicians. A systematic review across disciplines is warranted. OBJECTIVES: To evaluate the evidence for the effects of manual therapies for treatment of patients with bronchial asthma. SEARCH STRATEGY: Trials were searched in computerized general (EMBASE, CINAHL and MEDLINE) and specialized databases (Cochrane Complementary Medicine Field, Cochrane Rehabilitation Field, ICL, and MANTIS). In addition, bibliographies from included studies were assessed, and authors of known studies were contacted for additional information about published and unpublished trials. Date of most recent search: December 1998. SELECTION CRITERIA: Trials were included if they: (1) were randomised; (2) included asthmatic children or adults; (3) examined one or more types of manual therapy; and (4) included clinical outcomes. DATA COLLECTION AND ANALYSIS: All three reviewers independently extracted data and assessed trial quality using a standard form. MAIN RESULTS: From an initial 316 unique citations, 48 full text articles were retrieved and evaluated, which resulted in nine citations to five RCTs (290 patients) suitable for inclusion. Trials could not be pooled statistically because studies that addressed similar interventions used disparate patient groups or outcomes. The methodological quality of one of two trials examining chiropractic manipulation was good and neither trial found significant differences between chiropractic spinal manipulation and a sham manoeuvre on any of the outcomes measured. Quality of the remaining three trials was poor. One small trial compared massage therapy with a relaxation control group and found significant differences in many of the lung function measures obtained. However, this trial had poor reporting characteristics and the data have yet to be confirmed. One small trial compared chest physiotherapy to placebo and one small trial compared footzone therapy to a no treatment control. Neither trial found differences in lung function between groups. REVIEWER'S CONCLUSIONS: There is insufficient evidence to support the use of manual therapies for patients with asthma. There is a need to conduct adequately-sized RCTs that examine the effects of manual therapies on clinically relevant outcomes. Future trials should maintain observer blinding for outcome assessments, and report on the costs of care and adverse events. Currently, there is insufficient evidence to support or refute the use of manual therapy for patients with asthma.
Adult↗
Deoxyribonuclease for cystic fibrosis.
BACKGROUND: Recombinant human deoxyribonuclease is currently used to treat pulmonary disease (the major cause of morbidity and mortality) in cystic fibrosis. OBJECTIVES: To determine whether the use of recombinant human deoxyribonuclease in cystic fibrosis is associated with improved mortality and morbidity as compared to placebo and to identify any adverse events associated with its use. To compare the efficacy of recombinant human deoxyribonuclease with other mucolytics. SEARCH STRATEGY: The Cochrane Cystic Fibrosis and Genetic Disorders Group specialist trials register which comprises references identified from comprehensive electronic database searches, hand searching relevant journals and abstracts from conferences. The company producing recombinant human deoxyribonuclease was also contacted. Date of the most recent search of the Group's specialised register: November 1999. SELECTION CRITERIA: All randomised and quasi-randomised trials where recombinant human deoxyribonuclease was compared to either placebo, standard therapy or another mucolytic for any duration, dose regimen and age of patient with cystic fibrosis of any disease severity. DATA COLLECTION AND ANALYSIS: Trials were independently assessed for inclusion criteria, methodological quality and data extraction by the two reviewers. Comparisons were between recombinant human deoxyribonuclease and placebo and recombinant human deoxyribonuclease and other mucolytics. The following outcomes were recorded: Mean % change from baseline in forced vital capacity (FVC), forced expiratory voloume at one second (FEV1) and weight, mean number of respiratory tract exacerbations, days intravenous and oral antibiotics used, mean number of days as inpatient, number of deaths, adverse events and the cost of therapy. MAIN RESULTS: Seven primary clinical trials were identified, totalling 1710 patients. Two further studies examined the health care cost of patients from one of the clinical trials. No eligible studies compared recombinant human deoxyribonuclease to another mucolytic. Five trials presented outcomes at up to one month, one at three months and one at six months. No reduction in mortality for treated patients was identified (Relative Risk (RR) at six month 1.01, 95%Confidence Interval (CI) 0.09, 11.11). Lung function improved to a greater extent in the treated groups (at six months Weighted Mean Difference (WMD) FEV1 5.7, 95%CI 4.18, 7.23, at three months 7.3, 95%CI 4.04, 10.65). Pooled data from the five trials of up to one month gave WMD 9.2 95%CI 0.93, 17. 6 although there was significant heterogeneity). Recombinant human deoxyribonuclease was well tolerated with no excess of serious adverse events (RR haemoptysis 0.89, 95%CI 0.54, 1.45, pneumothorax 0.97 95%CI 0.19, 4.96). Voice alteration was, however, reported more frequently in the treated groups (RR 2.33 95%CI 1.38, 3.93). No study analysed our pre-defined outcome measure for respiratory exacerbations and insufficient data was available to analyse differences in antibiotic treatment, inpatient stay and quality of life. REVIEWER'S CONCLUSIONS: Studies are of insufficient duration to identify a reduction in mortality or number of respiratory exacerbations. Further trials are required to answer these important questions. Recombinant human deoxyribonuclease therapy is associated with an improvement in lung function after six months treatment, but it is not possible to assess whether this effect on lung function is sustained in the long-term. No studies were identified that compared recombinant human deoxyribonuclease to another mucolytic.
Cystic Fibrosis↗
Tumour oxygenation levels correlate with dynamic contrast-enhanced magnetic resonance imaging parameters in carcinoma of the cervix.
BACKGROUND AND PURPOSE: The Eppendorf pO(2) histograph is the 'gold standard' method for measuring tumour oxygenation. The method is not suitable for widespread application because its use is limited to accessible tumours. A non-invasive imaging technique would be an attractive alternative. Therefore, the relationships between tumour oxygenation and dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters were investigated. MATERIALS AND METHODS: The study comprised 30 patients with carcinoma of the cervix. Tumour oxygenation was measured pre-treatment as median pO(2) and the proportion of values less than 5 mmHg (HP5) using a pO(2) histograph. Repeat measurements were obtained for nine patients following 40-45 Gy external beam radiotherapy giving a total of 39 measurements. Dynamic contrast-enhanced MRI using gadolinium was performed prior to obtaining the oxygenation data. Time/signal intensity curves were generated to obtain two standard parameters: maximum enhancement over baseline (SI-I) and the rate of enhancement (SI-I/s). RESULTS: Using the 39 measurements, there was a significant correlation between SI-I and both median pO(2) (r=0.59; P<0.001) and HP5 (r=-0. 49; P=0.002). There was a weak, borderline significant correlation between SI-I/s and both median pO(2) (r=0.29; P=0.071) and HP5 (r=-0. 34; P=0.037). There was a significant relationship between tumour size and SI-I (r=0.54; P<0.001), but not SI-I/s. In 29 tumours, where data were available, there was no relationship between histological assessment of tumour angiogenesis (intra-tumour microvessel density; IMD) and either MRI parameter. CONCLUSIONS: Tumour oxygenation levels measured using a pO(2) histograph correlate with dynamic contrast-enhanced MRI parameters. Therefore, non-invasive dynamic MRI may be a method for measuring hypoxia in human tumours.
Adult↗
Magnetic resonance imaging screening in women at genetic risk of breast cancer: imaging and analysis protocol for the UK multicentre study. UK MRI Breast Screening Study Advisory Group.
The imaging and analysis protocol of the UK multicentre study of magnetic resonance imaging (MRI) as a method of screening for breast cancer in women at genetic risk is described. The study will compare the sensitivity and specificity of contrast-enhanced MRI with two-view x-ray mammography. Approximately 500 women below the age of 50 at high genetic risk of breast cancer will be recruited per year for three years, with annual MRI and x-ray mammography continuing for up to 5 years. A symptomatic cohort will be measured in the first year to ensure consistent reporting between centres. The MRI examination comprises a high-sensitivity three-dimensional contrast-enhanced assessment, followed by a high-specificity contrast-enhanced study in equivocal cases. Multiparametric analysis will encompass morphological assessment, the kinetics of contrast agent uptake and determination of quantitative pharmacokinetic parameters. Retrospective analysis will identify the most specific indicators of malignancy. Sensitivity and specificity, together with diagnostic performance, diagnostic impact and therapeutic impact will be assessed with reference to pathology, follow-up and changes in diagnostic certainty and therapeutic decisions. Mammography, lesion localisation, pathology and cytology will be performed in accordance with the UK NHS Breast Screening Programme quality assurance standards. Similar standards of quality assurance will be applied for MR measurements and evaluation.
Adult↗
A randomized, placebo-controlled study to evaluate the role of salmeterol in the in-hospital management of asthma.
STUDY OBJECTIVES: To assess the safety and efficacy of salmeterol xinafoate as an adjunct to conventional therapy for the in-hospital management of acute asthma. DESIGN: A prospective, double-blind, randomized placebo-controlled trial. SETTING: Medical wards of a large university-based hospital. PATIENTS: Forty-three patients admitted for an acute exacerbation of asthma. INTERVENTIONS: Salmeterol (42 microg) or two puffs of placebo every 12 h in addition to standard therapy (short-acting beta-agonists, corticosteroids, and anticholinergic agents). RESULTS: No clinically adverse effects were seen with the addition of salmeterol to conventional therapy. After salmeterol, there was no difference in pulse, respiratory rate, oxygen saturation by pulse oximetry, severity of symptoms, or dyspnea score. Patients receiving salmeterol had greater FEV(1) percent improvements than the placebo group at 12, 24, 36, and 48 h. These findings were not statistically significant. By paired Student's t tests, there were significant improvements in FEV(1) (p = 0.03) and FVC (p = 0.03) in the salmeterol group after 48 h of treatment with no comparable improvement in the placebo group. In a subgroup analysis of patients with an initial FEV(1) < or = 1.5 L, the absolute FEV(1) percent improvement for salmeterol vs placebo was 51% vs 16% at 24 h and 54% vs 40% at 48 h. The relative FEV(1) percent improvement for salmeterol vs placebo was 17% vs 8% at 24 h and 18% vs 14% at 48 h. CONCLUSION: The addition of salmeterol to conventional therapy is safe and may benefit hospitalized patients with asthma. Further studies are needed to clarify its role in the treatment of acute exacerbation of asthma.
Acute Disease↗
Asthma and the home environment.
Recent years have seen a global increase in asthma prevalence. This has coincided with modifications to the home environment resulting in changes to the indoor air quality. This article considers the links between indoor pollution and asthma. Exposure to a range of substances is examined. Airborne allergens such as those from house dust mites may be important. Pollution from particulate materials associated with combustion and smoking is discussed, as is the role of chemical vapors and gases including nitrogen dioxide, sulfur dioxide, and volatile organic compounds. The efficacy of various environmental controls to limit the impact of these pollutants is explored.
Air Pollution, Indoor↗
Factors in the reproducibility of electromyographic power spectrum analysis of lumbar paraspinal muscle fatigue.
STUDY DESIGN: An investigation of the reliability of various factors used to analyze electromyograms of paraspinal muscles of the lumbar spine. OBJECTIVES: To determine the reproducibility of several electromyographic variables over time and to assess the influence of confounding factors. SUMMARY OF BACKGROUND DATA: Previous reliability studies have included small numbers of subjects and often have not explored the factors that can influence the reliability of this technique. METHODS: In the first study, 39 volunteers underwent electromyographic tests on three occasions at two loads. The time interval was 1 week between tests. Electromyographic variables measured included half-width (spectral width at half maximum amplitude), initial median frequency, median frequency slope, initial root mean square, root mean square, and root mean square slope. In the second study to determine the influence of posture, nine volunteers were tested on two occasions with a change in posture between tests. RESULTS: Reliability was better for tests at the higher loads. Initial median frequency, half-width, and root mean square all had acceptable reproducibility over time, with a coefficient of variation less than 10. Initial median frequency and half-width proved to be the most suitable variables; they yielded the largest between-subject variation and, of all variables, were affected the least by changes in load. The remaining variables were very load-dependent. A change in posture greatly influenced the reproducibility. CONCLUSION: These results demonstrate that only initial median frequency and half-width have acceptable reproducibility over time and at different loads, with the potential to be useful in discriminating between individuals. Changes in posture can greatly change an electromyographic result.
Adult↗
Health service accessibility and deaths from asthma.
BACKGROUND: Good access to health services may be important for effective asthma management amongst patients, thus preventing unnecessary deaths. In a previous study, we found elevated levels of asthma mortality in English local authority districts with poor access to acute hospitals. Here, the relationship between asthma mortality and access to primary and secondary services within the rural region of East Anglia is examined. METHODS: A geographically based descriptive study, within 536 electoral wards in the region of East Anglia, England. Regression analysis was used to examine the relationship between health service accessibility, and mortality from asthma during the period January 1985 to December 1995. RESULTS: After controlling for confounding factors, there was a significant tendency for asthma mortality to increase with travel time to hospital, with a relative risk of 1.07 for each 10-minute increase in journey time (P = 0.04). There was no consistent trend for mortality to increase with travel time to general practitioner surgeries. CONCLUSIONS: The results of this study support the conclusions of earlier work that inaccessibility of acute hospital services may increase the risk of asthma mortality. The provision of good access to these facilities may be one factor in reducing the burden of avoidable deaths from asthma.
Asthma↗
Assessment of spinal musculature using surface electromyographic spectral color mapping.
STUDY DESIGN: A technique is described for analyzing electromyogram data from lumbar spinal muscles, with special reference to discrimination of people with back pain. The ability to discriminate was evaluated in 99 people (61 healthy and 38 with chronic or acute back pain), and the influence of load was assessed. OBJECTIVES: To evaluate methods of analysis of complex electromyogram data and to assess correlation of electromyogram information with clinical condition in people with and without back pain. SUMMARY OF BACKGROUND INFORMATION: In previous analyses of electromyogram data, only a small part of the data have been used. Spinal muscular decompensation has been postulated in chronic low back pain, but there has been no direct demonstration of this phenomenon. Objective measures are still elusive. METHODS: Lumbar spinal surface electromyograms were recorded during an isometric lifting task. The data were represented graphically as color-coded plots of electromyogram frequency, time, and electromyogram amplitude. Spectral width at half-peak amplitude (spectral half width) was calculated from the digitized, summed data. Ninety-nine people were tested: 48 men (29 with no recent [in the past 2 years] history of back pain, 16 with chronic back pain, 3 with acute back pain) and 51 women (32 with no recent back pain and 19 with chronic back pain). RESULTS: Spectral color maps in people with chronic back pain were markedly different from those in healthy people. Spectral half width was greater in people with chronic back pain than in healthy people (P < 0.01). Blinded analysis of spectral color maps allowed discrimination of people with back pain from healthy people with a sensitivity of 76% and a specificity of 81%. People with a history of back pain had markedly variable half widths. CONCLUSIONS: A new method of analysis of electromyogram data from lumbar spinal muscles has allowed discrimination between people with back pain and healthy people. This provides direct evidence of a correlation between muscular electrical function, measured by electromyogram, and low back pain. This technique may have potential as an objective measurement tool.
Adolescent↗
Asthma and domestic air quality.
In recent years, there has been a global increase in the prevalence of asthma. This has coincided with many modifications to the home environment, resulting in changes to the quality of indoor air. This article considers the links between indoor air pollution and asthma. Exposure to a range of pollutants is examined. Airborne allergens such as those from house dust mites and cockroaches, domestic pets and moulds and fungal spores may be important. Pollution from particulate materials associated with bio-fuel combustion and smoking is discussed, as is the role of chemical vapours and gases including nitrogen dioxide, formaldehyde and volatile organic compounds. The efficacy of various environmental controls to limit the impact of these pollutants is explored. It is concluded that indoor air pollution may be an important risk for asthma and the health impacts of building design and management require greater recognition and further research.
Air Pollutants↗