Role of extracorporeal membrane oxygenation.
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Extracorporeal Membrane Oxygenation↗
Biomedical subjects
S Richmond
Publications and source records attributed to S Richmond.
Digital imaging of cephalometric radiography, Part 1: Advantages and limitations of digital imaging.
Digital imaging has several potential advantages over traditional cephalometry. These include storage, transmission, and enhancement of images, reduced exposure to radiation for patients, and the possibility of automated cephalometric analysis. This paper outlines some of these advantages, discusses the limitations of digital imaging and suggests possible future developments.
Cephalometry↗
Digital imaging of cephalometric radiographs, Part 2: Image quality.
The aim of this study was to compare the diagnostic quality of conventional cephalometric radiographs with that of digital image counterparts. The random error associated with angular and linear measurements recorded on the digital images was greater than on the conventional radiographs. In addition, there was a systematic error producing statistically significant differences in the majority of angular and linear measurements between the digital images and the conventional radiographs. The errors that occurred with some measurements were of sufficient magnitude to be of clinical significance, particularly in a cephalometric situation where a high degree of accuracy is required. It is therefore suggested that, for digital imaging of cephalometric radiographs, a pixel matrix larger than 512 x 512 with more than 64 gray levels is required to maintain the diagnostic quality of the original radiograph.
Cephalometry↗
Serial measures of total body oxygen consumption in an awake canine model of septic shock.
We examined serial changes in total body oxygen consumption (Vo2) in a permanently tracheotomized canine sepsis model. On Day 0, beagles had an Escherichia coli-infected (septic) or sterile (control) clot surgically placed in the peritoneum. During the 21-d study, 10 of the 16 septic animals and none of the six control animals died (p = 0.02). After clot placement septic versus control animals had decreased mean arterial blood pressure (mm Hg; Day 1: 106 versus 128, p = 0.055; Day 2: 95 versus 125, p = 0.004, respectively) and left ventricular ejection fraction (Day 1: 0.44 versus 0.69, p = 0.0006; Day 2: 0.33 versus 0.57, p = 0.0001, respectively). Despite significant lethality and cardiovascular dysfunction, in the septic group on Days 1 and 2, septic versus control animals had no significant differences in mean metabolic cart measured (Vo2DIR, ml/kg/min; Day 1: 11.9 versus 12.4, p = 0.81; Day 2: 14.2 versus 13.5, p = 0.72, respectively) and intravascular catheter calculated (Vo2INDIR, ml/kg/min; Day 1: 11.2 versus 11.2, p = 0.99; Day 2: 12.8 versus 15.4, p = 0.49, respectively). On Day 1 in septic and control animals, volume infusion produced increases (p < 0.001) in oxygen delivery (Do2). In septic and control animals these changes in Do2 were similar and were associated with similar increases in Vo2DIR (p = 0.001), and Vo2INDIR (p = 0.001). In fact, at all time points studied (baseline, Day 1, 2, and 21), both before and after volume infusion, levels of Do2, Vo2DIR, and Vo2INDIR did not differ between septic and control animals, nor did they differ between septic survivors and nonsurvivors. Because levels of Vo2DIR and Vo2INDIR were similar in both groups, we pooled data from septic and control animals. Throughout the study, Vo2 showed a moderate association with Vo2INDIR (r = 0.55, p = 0.003), but mean Vo2DIR was lower at baseline (p = 0.001) and on Day 21 (p = 0.07) and greater on Day 2 (p < 0.01). In summary, our techniques, which detected small changes in both Vo2DIR and Vo2INDIR occurring with volume infusion, did not demonstrate differences in these parameters comparing control and septic animals. These results in euvolemic septic animals suggest that total body Vo2 may not reflect pathogenetic mechanisms during sepsis and septic shock. Furthermore, these results suggest that although the level of total body Vo2 may reflect the effects of therapeutic interventions such as volume loading, it should not itself serve as a therapeutic target.
Animals↗
Assessment of General Dental Services orthodontic standards: the Dental Practice Board's gradings compared to PAR and IOTN.
The subjective grading of cases at the Dental Practice Board of England and Wales was compared to the Peer Assessment Rating Index (PAR) and Index of Orthodontic Treatment Need (IOTN) in assessing 1505 cases sampled at the Board between late 1990 and mid-1991. Whilst some criteria are common to both systems, case by case there is only limited agreement; sources of disagreement are evaluated. The indices are essentially epidemiological tools; whilst they have short-comings in assessing individual cases, they are related to peer opinion, and show good reliability when used on samples of cases. They can be readily updated, as findings of research or future peer opinion may dictate. Use of PAR and IOTN at the Board, instead of subjective gradings, would require a departure from decisions on withholding payment on a case by case basis. If, however, they were used on samples of practitioners' caseloads to assess reduction of malocclusion, and residual malocclusion and need for treatment, practitioners fees could be up- or down-graded periodically according to their overall performance, to encourage more to adopt higher standards. Allowances could be made, however, for 'limited objective treatments' and cases where poor co-operation had impaired the result.
Dental Health Surveys↗
A critical assessment of orthodontic standards in England and Wales (1990-1991) in relation to changes in prior approval.
Targeting, use of appliances, and standards of outcome for General Dental Service orthodontic cases collected between 1990 and 1991 were compared with a sample of cases from an earlier study, collected between 1987 and 1988, using the PAR index and IOTN. Comparisons are made generally and in relation to the changes in prior approval regulations for cases started since October 1987. More lower-need cases were treated, but there were no more "unnecessary' treatments and there has been a limited improvement in outcomes, as assessed by the indices, associated with increased use of fixed appliances since 1987. Prior approval appeared to give no tangible benefits in terms of levels of unnecessary treatment or quality of outcome.
England↗
Health gain in orthodontics: a comparison of the general dental services and the hospital service in England and Wales.
The aim of this paper was to assess the health gain in orthodontics achieved by practitioners in the General Dental Service (GDS) and Hospital Dental Service (HDS) and the relative probabilities in achieving health gain in relation to the presenting occlusal trait. In a sample of 1225 patients in the GDS in England and Wales and 1365 cases in the HDS different levels of health gain were found. Occlusal traits are most likely to be treated more successfully in the HDS. Seven out of every ten patients in the HDS were likely to achieve health gain as opposed to four out of every ten patients in the GDS.
Dental Service, Hospital↗
The relationship between the index of orthodontic treatment need and consensus opinion of a panel of 74 dentists.
This study looked at the aesthetic and dental health components of the index of orthodontic treatment need in relation to peer assessment of dental health and aesthetic need (panel of 74 dentists). The dental health component had a Spearmans correlation coefficient of +0.64 and the aesthetic component +0.86 when compared with the mean subjective opinion of 74 dentists. It has been proposed to have three categories for both the dental health and aesthetic components in accordance with consensus opinion. The panel of 74 examiners were more likely to regard aesthetics as a greater need for treatment than dental health.
Attitude of Health Personnel↗
The use of occlusal indices: a European perspective.
Although occlusal indices are used in connection with public health orthodontic programs in some states, their adoption in everyday practice in the United States is extremely limited. On the other hand, indices are used extensively in Northern Europe, especially in determining access to public health orthodontics or the level of third party copayment. This article describes the development and validation of two new indices, IOTN (an index of treatment need) and PAR (an index of treatment outcome). Their application in a series of studies has led us to conclude that occlusal indices have a role in resource allocation and planning, promoting treatment standards, identifying prospective patients, and informed consent.
Europe↗
Calibration of dentists in the use of occlusal indices.
Dentists' opinions as to both need for and outcome of orthodontic treatment show wide variation. Within the profession there is an opportunity to reduce subjective bias and standardise criteria by the use of occlusal indices. The results of this study demonstrate that a group of dentists can easily be trained to record the Aesthetic and Dental Health Components of the Index of Orthodontic Treatment Need and the PAR index to a satisfactory level.
Bias↗
Antenatal diagnosis of congenital heart disease and Down's syndrome: the potential effect on the practice of paediatric cardiology.
OBJECTIVE: To predict the effect of antenatal ultrasound screening for congenital heart disease and maternal serum screening of Down's syndrome on the practice of paediatric cardiology and paediatric cardiac surgery. DESIGN: A retrospective and prospective ascertainment of all congenital heart disease diagnosed in infancy in 1985-1991. SETTING: One English health region. PATIENTS: All congenital heart disease diagnosed in infancy by echocardiography, cardiac catheterisation, surgery, or necropsy was classified as "complex", "significant", or "minor" and as "detectable" or "not detectable" on a routine antenatal ultrasound scan. RESULTS: 1347 infants had congenital heart disease which was "complex" in 13%, "significant" in 55%, and "minor" in 32%. 15% of cases were "detectable" on routine antenatal ultrasound. Assuming 20% detection and termination of 67% of affected pregnancies, liveborn congenital heart disease would be reduced by 2%, infant mortality from congenital heart disease by 5%, and paediatric cardiac surgical activity by 3%. Maternal screening for Down's syndrome, assuming 75% uptake, 60% detection, and termination of all affected pregnancies, would reduce liveborn cases of Down's syndrome by 45%, liveborn cases of congenital heart disease by 3.5%, and cardiac surgery by 2.6%. CONCLUSIONS: Screening for congenital heart disease using the four chamber view in routine obstetric examinations and maternal serum screening for Down's syndrome is likely to have only a small effect on the requirements for paediatric cardiology services and paediatric cardiac surgery.
Cardiac Surgical Procedures↗
Discontinued orthodontic treatment in the general dental services of England and Wales (1990-1991).
Relevant feature of a sample of discontinued treatments were investigated, including status at the start and at the time of discontinuation. In a comparison between two discontinued groups, those patients who simply failed to return tended to have lower pretreatment PAR scores, and were more likely to have received non-extraction treatments in which removable appliances were employed. However, when discontinued treatments were compared to completed treatments undertaken in 1987/8, the completed cases were only reduced by two further PAR points.
Adolescent↗
Emergency transport for neonates after home deliveries. Expectations of flying squads are too high.
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Emergency Medical Services↗
Training SHOs to resuscitate newborn infants.
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England↗
Enamel sealants: a clinical evaluation of their value during fixed appliance therapy.
A clinical trial was undertaken to evaluate the effectiveness of two new enamel sealing systems in the prevention of enamel decalcification following bracket bonding. Eighty patients undergoing fixed appliance therapy were included. Of these, 40 were treated with a viscous chemically-cured sealant and bonding system (Maximum Cure), while 40 patients were treated using a non-viscous visible light-cured sealant and bonding agent (Transbond resin). Alternate teeth were used as controls where no sealant was used. A total of 289 experimental and 282 control teeth were included in the chemically-cured sealant group, the figures for the light-cured sealant group being 306 and 305, respectively. Enamel decalcification incidence and distribution were recorded using a modified index by direct clinical observation. The results showed that 75 per cent of patients were affected by some decalcification. The viscous sealant reduced the extent of decalcification of tooth zones by 13 per cent. The non-viscous sealant produced no significant difference. Over 60 per cent of decalcification occurred in the gingival areas. Maxillary lateral incisors and canines, and mandibular canines and second premolars were the teeth most severely affected, and the most likely to benefit from sealing. Further research is needed to develop a material which provides greater enamel protection.
Bisphenol A-Glycidyl Methacrylate↗
Presentation of obstructive left heart malformations in infancy.
This study documents the presentation of acutely life threatening congenital heart disease in infancy in order to assess the performance of screening examinations soon after birth and at 6 weeks of age. All cases of obstructive left heart malformations presenting in infancy in one health region from 1987-91 were analysed retrospectively. Altogether, 120 infants presented with either hypoplastic left heart syndrome, interruption of the aortic arch, coarctation of the aorta, or aortic valve stenosis. Twelve became symptomatic or died within 24 hours. Thirty four had an abnormal neonatal examination, eight of whom were referred. Six more became symptomatic before discharge. Ninety four babies went home, 51 developed heart failure before 6 weeks, and another seven died without diagnosis. Twenty five of 36 (69%) reaching 6 weeks without diagnosis had a second examination which was abnormal in 17. Two babies died undiagnosed after 6 weeks and the other 18 presented at up to 11 months of age. The neonatal and 6 week examinations perform poorly as screening tests for congenital heart disease. A normal neonatal examination does not exclude life threatening congenital heart disease.
Aorta, Thoracic↗
Dentists variation in the determination of orthodontic treatment need.
The criteria that dentists use to judge the need for orthodontic treatment are not clear. This study investigates variation in dentists' perception of orthodontic treatment need. Seventy-four dentists were asked to assess 320 dental casts in relation to aesthetic and dental health need. The results of this investigation revealed that the panel was divided as what constituted a need for orthodontic treatment on dental health grounds. It is suggested that one method of achieving a more uniform evaluation of orthodontic treatment need is the use of an occlusal index. Until an occlusal index is accepted and used by the profession, the distortion of need and demand for orthodontic treatment by dentists' unequal perceptions will continue.
Attitude of Health Personnel↗
Use of the Index of Orthodontic Treatment Need (IOTN) in assessing the need for orthodontic treatment pre- and post-appliance therapy.
The Index of Orthodontic Treatment Need (IOTN) was used to assess the need for orthodontic treatment before and after treatment, on a systematic sample of 1225 cases. On the whole, full upper and lower fixed appliances brought about a greater improvement in Aesthetics and Dental Health Components compared to other appliance techniques, and were less likely to make the occlusion worse. It was found that certain occlusal traits were more likely to be successfully treated than others. A common problem resulting from treatment was the development of a cross-bite.
Dental Health Surveys↗