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Biomedical subjects

P Carson

Publications and source records attributed to P Carson.

At least 19 recordsLinked to original sources
PubMed2003

Relative analgesia and general dental practitioners: attitudes and intentions to provide conscious sedation for paediatric dental extractions.

AIM: To examine the attitudes and intentions of general dental practitioners (GDPs) who work within the remit of the National Health Service (NHS) to provide relative analgesia (RA) for paediatric extractions. METHODS: All 45 GDPs working within the boundaries of one Trust were asked to complete a questionnaire to assess demography, etc., intention and attitudes to provide RA for paediatric extractions. RESULTS: Ninety-eight per cent of GDPs took part. All GDPs worked within the NHS. Twenty-nine per cent of GDPs stated that they had RA equipment available in their practices and 68% stated that they discussed RA as treatment alternative. Eighty-seven per cent referred their paediatric extraction cases for dental general anaesthesia. The behavioural intention was predicted by total attitude score and the availability of RA equipment in the practice (R2=0.97, F(37,5)=260.11, P<0.001). Total attitude was predicted by clinical competency, few financial worries or time concerns and the availability of RA equipment (R2=0.91, F(38,4)=106.21, P<0.001). CONCLUSIONS: This study suggests that GDPs' concerns of clinical competence and costs have an inhibiting effect upon their intention to provide RA for paediatric extractions. These concerns must be addressed by planners and policy makers if there is to be a shift from hospital-based DGA to surgery-based RA services for paediatric extractions.

Analgesia↗
PubMed2001

Angiotensin receptor blockers: evidence for preserving target organs.

Hypertension is a major problem throughout the developed world. Although current antihypertensive treatment regimens reduce morbidity and mortality, patients are often noncompliant, and medications may not completely normalize blood pressure. As a result, current therapy frequently does not prevent or reverse the cardiovascular remodeling that often occurs when blood pressure is chronically elevated. Blockade of the renin-angiotensin system (RAS) is effective in controlling hypertension and treating congestive heart failure. Both angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) inhibit the activity of the RAS, but these two classes of antihypertensive medications have different mechanisms of action and different pharmacologic profiles. Angiotensin-converting enzyme inhibitors block a single pathway in the production of angiotensin II (Ang II). In addition, angiotensin I is not the only substrate for ACE. The ACE inhibitors also block the degradation of bradykinin that may have potential benefits in cardiovascular disease. Bradykinin is, however, the presumed cause of cough associated with ACE inhibitor therapy. Data from clinical trials on ACE inhibitors serve to support the involvement of the RAS in the development of cardiovascular disease. Angiotensin receptor blockers act distally in the RAS to block the Ang II type 1 (AT1) receptor selectively. Thus, ARBs are more specific agents and avoid many side effects. Experimental and clinical trials have documented the efficacy of ARBs in preserving target-organ function and reversing cardiovascular remodeling. In some instances, maximal benefit may be obtained with Ang II blockade using both ARBs and ACE inhibitors. This review describes clinical trials that document the efficacy of ARBs in protecting the myocardium, blood vessels, and renal vasculature.

Angiotensin Receptor Antagonists↗
PubMed2001

Beta-blocker therapy in heart failure.

beta-blocker therapy in heart failure offers the possibility of arresting or reversing the progressive deterioration in this clinical syndrome. While the mechanism is unclear, improvement in cardiac function has been apparent in virtually every study. Clinical results have shown less consistent improvement. Decrease in hospitalization has been noted, but large-scale clinical trials are underway to assess the effect of beta-blockers on mortality.

Adrenergic beta-Antagonists↗
PubMed2001

Healing of venous ulcers of long duration with a bilayered living skin substitute: results from a general surgery and dermatology department.

BACKGROUND: A laboratory-grown bilayered living skin substitute (LSS) has been shown to accelerate the healing of venous ulcers. However, issues related to optimal wound bed preparation prior to the application of LSS have not been addressed. OBJECTIVE: When combined with standard compression therapy and near elimination of wound exudate, bioengineered skin can achieve complete closure of venous ulcers which have been present for more than a year and which are difficult to heal. METHODS: In the general surgery (center A) and dermatology (center B) departments at two separate medical centers, LSS was used to treat venous ulcers of more than 1 year's duration and which had been unresponsive to conventional therapy. Wound bed preparation at both centers had as common goals the removal of necrotic tissue, optimal formation of granulation tissue, and elimination of wound exudate. RESULTS: There was great comparability between the two centers in the patients being treated, wound size and duration, and number of LSS applications. Both centers achieved a frequency of complete wound closure of greater than 70% within 6 months. CONCLUSION: At two separate clinical and specialty sites having a common goal of optimal wound preparation, treatment with LSS was associated with a high rate of complete closure of hard to heal venous ulcers.

Aged↗
PubMed2001

Dental caries, age and anxiety: factors influencing sedation choice for children attending for emergency dental care.

OBJECTIVES: The aim of the study was to examine how physical (dental caries) and psychosocial (age, dental anxiety and dental health behaviour) factors, associated with child and parent, influenced dentists' sedation choice when a child presents in pain. METHODS: 600 parents whose children were aged between 5 and 11 years took part: 200 attended for routine dental care (RDC); the remaining 400 attended as emergency patients and were offered either dental general anaesthesia (DGA) or relative analgesia (RA). The subjects were approached and invited to take part. The researcher was blind as to the child's pattern of dental attendance and the type of sedation offered. All parents and children completed self-reported ratings of dental anxiety. The children's teeth were examined to determine past and present dental caries experience. RESULTS: The results showed that children who were offered DGA had greater experience of dentinal caries, were younger and dentally anxious. The children offered RA were older, had a higher frequency of brushing their teeth with fluoride toothpaste and were also dentally anxious. Discriminant analysis showed that 2 canonical functions provided clear categorisation of the three treatment groups. Function 1 was a physical (dental caries) factor, which was related to the child's experience of dentinal caries. Function 2 was a psychosocial factor, which was related to the child's age, dental anxiety and frequency of tooth brushing. A greater proportion of the variance in the treatment offered was explained by Function 1, suggesting that the most important factor in the decision to offer DGA was dentinal caries. Function 2 was of lesser importance. CONCLUSIONS: The findings have implications for the type of sedation offered to children presenting for emergency care. These children may not otherwise receive treatment and the need to provide less anxiety provoking forms of sedation must be promoted. By doing so, parents who have only brought their children when in pain may take advantage of RDC and the treatments offered to prevent and control dental caries and anxiety in their children.

Age Factors↗
PubMed2000

Characteristics of children attending for dental general anaesthesia in 1993 and 1997.

OBJECTIVES: To confirm clinical observations and to investigate the characteristics (demography, dental anxiety status, dental health status, treatment experiences and dental health behaviours) of children attending for dental general anaesthesia (DGA). DESIGN: A case series design was used in which each consecutive parent and child, referred for DGA, were invited to take part. METHOD: Identical protocols for the selection of the sample, administration of the questionnaire and clinical examination were used to ensure comparability. To account for seasonal variation the data were collected during and between the months of January and May in both 1993 and 1997. Two hundred children and their parents were selected in 1993 and 200 in 1997. The parent completed a questionnaire. It enquired of the parent and child demography, parental dental anxiety status, and the child's treatment experiences. Children were asked to complete the Children's Fear Survey Schedule (CFSS) to assess their dental anxiety. The child's caries experience was assessed using the guidelines to standardise the collection of epidemiological data throughout the UK. RESULTS: Children studied in 1997 compared with 1993 were younger, had more decayed but fewer filled teeth, were more dentally anxious, more likely to present in pain and came from families who were in receipt of Government benefits. A linear regression analysis showed that the children with previous experience of DGA had higher levels of dental caries, fewer filled teeth, were older and attended in 1997. An individual regression for 1993 showed that an additional predictor was child attendance pattern. CONCLUSIONS: These findings confirmed the clinical observations and suggested that children who attend in pain and present for repeated DGA represent a group of children with special dental healthcare needs. There is a need for an integrated dental healthcare service to identify such children and provide appropriate dental care facilities for them.

Anesthesia, Dental↗
PubMed1999

Racial differences in response to therapy for heart failure: analysis of the vasodilator-heart failure trials. Vasodilator-Heart Failure Trial Study Group.

BACKGROUND: Heart failure in blacks has been associated with a poorer prognosis than in whites. In such diseases as hypertension, blacks show pathophysiological differences and respond differently to some therapies than whites. The aim of this study is to evaluate the clinical characteristics and response to therapy of black compared with white patients with heart failure. METHODS AND RESULTS: In the first Vasodilator-Heart Failure Trial (V-HeFT I), 180 black male patients were compared with 450 white male patients for baseline characteristics, prognosis, and response to therapy. In V-HeFT II, the same comparisons were made for 215 black and 574 white male patients, including an analysis stratified by the presence or absence of a history of hypertension. In both trials, black patients had a lower incidence of coronary artery disease, greater incidence of previous hypertension, and a greater cardiothoracic ratio (P < .05) than white patients. In V-HeFT II, plasma norepinephrine levels were significantly less in blacks; plasma renin activity was less only in blacks with a history of hypertension. Overall mortality or hospitalization for congestive heart failure did not differ between blacks and whites in the placebo group in V-HeFT I. However, the mortality of black patients receiving hydralazine plus isosorbide dinitrate (H-I) was reduced (P = .04) in V-HeFT I, whereas white patients showed no difference from placebo. In V-HeFT II, only white patients showed a mortality reduction from enalapril therapy compared with H-I therapy (P = .02). Whites also showed evidence of greater blood pressure reduction and enhanced regression of cardiac size in response to enalapril. When stratified by history of hypertension in V-HeFT II, only whites with a history of hypertension, who had greater renin levels, showed significant mortality reduction with enalapril compared with H-I therapy. Hospitalization rates did not differ between treatment groups in either study. CONCLUSION: Whites and blacks showed differences in cause, neurohormonal stimulation, and pharmacological response in heart failure. This retrospective analysis suggests angiotensin-converting enzyme inhibitors are particularly effective in whites, and the H-I combination can be equally effective in blacks. Prospective trials involving large numbers of black patients are needed to further clarify their response to therapy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

Effect of inotrope withdrawal on morbidity and mortality in patients with chronic heart failure: results of the vesnarinone trial withdrawal substudy. Vest Withdrawal Substudy Group.

BACKGROUND: The use of inotropic agents in the therapy of patients with congestive heart failure (CHF) is controversial. One concern regarding inotropic therapy has been that drug withdrawal could be associated with a worsening of symptoms. METHODS AND RESULTS: We took advantage of the discontinuation of the recent trial of vesnarinone in the therapy of CHF to assess the effects of withdrawal of the inotropic agent, vesnarinone, in patients with chronic CHF who had been randomized to receive either placebo or 30 or 60 mg of vesnarinone. Contrary to our initial hypothesis, withdrawal of vesnarinone did not impact on either morbidity or mortality over a period of 6 months. CONCLUSION: Although these results suggest vesnarinone withdrawal is safe, the applicability of these results to other inotropic agents remains unclear.

Cardiotonic Agents↗
PubMed1999

Identification of clinical risk factors for nosocomial pneumococcal bacteremia.

Clinical risks for nosocomial pneumococcal bacteremia (NPB) have been analyzed previously in case series, a study design inadequate for this purpose. Therefore, we performed a case-control study of NPB, pairing each of 37 cases identified retrospectively at the Minneapolis Veterans Affairs Medical Center from the period of 1984-1994 with four or five hospitalized controls. Comorbidities identified at the time of admission that were significantly associated with NPB on univariate and multivariate analysis included respiratory or hematologic malignancy, anemia, chronic obstructive pulmonary disease, and coronary artery disease. All characteristic symptoms and signs of pneumococcal infection were significantly more common in cases than in controls. NPB was strongly associated with death within 7 days of the index blood culture date, and the mortality rate among cases was 40.5%, compared with 1.2% among nonbacteremic controls (P < .00001). We conclude that NPB is a highly lethal infection that is associated with distinct but identifiable clinical risks, symptoms, and signs.

Aged↗
PubMed1999

The performance of a fluoroscopic electronic portal imaging device modified for portability.

Advances in external beam therapy technology have made routine, efficient conformal therapy a reality. With it comes the increasing need for online treatment verification, which is only achievable at present through the use of electronic portal imaging devices (EPIDs). For a large radiotherapy centre, the provision of one EPID per treatment machine proves extremely expensive. This paper details modifications to the design of a commercial fluoroscopic EPID (the SRI-100) to produce a portable system, capable of providing quick, high quality imaging on more than one treatment machine. We describe the necessary hardware and software changes made to the system, as well as the variety of mechanical and quality control checks performed for testing the stability and quality of the imaging. The modified system has been found to be both electronically and mechanically robust, with associated image quality, scaling, distortion and movement similar to other EPIDs in the department. Although the modification was designed specifically to allow for the acquisition of images from multiple treatment machines, it may also enable the operation of the EPID for other uses such as total body irradiation (TBI) treatment verification and a further range of quality control procedures on the linear accelerator itself.

Ambulatory Care↗
PubMed1998

The safety and efficacy of a proteolytic ointment in the treatment of chronic ulcers of the lower extremity.

BACKGROUND: Elase is a widely used ointment consisting of a combination of 2 proteolytic enzymes, fibrinolysin and desoxyribonuclease (DNAse). It is said to promote debridement of necrotic and purulent debris from skin ulcers. OBJECTIVE: Our purpose was to assess the efficacy and safety of this ointment and its components in the treatment of chronic ulcers of the lower extremity. METHODS: This was a double-blind, randomized, prospective study of 84 patients with leg ulcers exhibiting necrotic and purulent debris, who were treated for 21 days with twice-daily applications of the ointment, fibrinolysin, DNAse, or who received the ointment vehicle (placebo). We assessed 6 efficacy features: ulcer size, purulent exudate, necrotic tissue, erythema, pain, and overall condition of the lesion at days 8, 15, and 21 after initiation of treatment. We also assessed the frequency of adverse effects. RESULTS: All treatments produced some improvement in the efficacy parameters and overall condition of the ulcers by week 3, but no statistically significant difference was found when compared with placebo. No serious adverse effects were noted. A later retrospective reanalysis of the data found a statistically significant reduction of purulent exudate only at days 3 and 7 of treatment in the group treated with the complete ointment, but not in the other features. CONCLUSION: The proteolytic ointment provides no long-term clinical benefit in reducing purulent exudate, pain, erythema, necrotic tissue, or overall condition of chronic leg ulcers when compared with either of its two components or placebo.

Adult↗
PubMed1997

Assessing child dental anxiety: the validity of clinical observations.

For children there are few validated psychometric measures of dental anxiety. The study reported here aims to examine the validity of using clinical observations as a measure of child dental fear. 100 children consecutively attending a community clinic were asked to complete the validated Child Fear Survey Schedule (CFSS). After the dental examination both dental nurse and dentist separately assessed the subject's dental fear using a checklist based on the CFSS schedule. High agreement was found between the child, the dentist and dental nurse respectively and principal components analysis suggested that a dual nature of anticipatory dental anxiety existed in children. The findings of this work suggest that clinical observations may be a valid means of assessing child dental anxiety status.

Child↗
PubMed1997

Open versus closed surgical treatment of abscesses: a controlled clinical trial.

BACKGROUND: Conventional drainage, curettage and packing of acute superficial abscesses has been challenged and in some centres replaced by curettage and primary closure under antibiotic cover. This technique has not been used widely in Australasia or North America, probably because of the lack of reassurance from local randomized trials. METHODS: A randomized trial was conducted to compare the primary closure of acute superficial abscesses to conventional packing. Abscesses requiring drainage under a general anaesthetic were considered for the study, excluding extensive, secondary and deep suppurations. In the 'open' group, the abscess was drained, curetted, irrigated, and then packed. Instead of packing, the cavity in the 'closed' group was obliterated using interrupted vertical mattress skin sutures with/without closed suction drainage. Other aspects of management were standardized. RESULTS: Of the 32 abscesses treated using the closed technique, 25 (78%) healed by primary intention after 1 week (SE(p) = 7.3%; 95% CI = 63.7-92.4%). One of the 29 abscesses (3%) treated using the open technique healed by secondary intention in a similar period of time. The difference was statistically significant (Chi-squared test with Yates' continuity correction = 31.70; P < 0.0001). There was no statistically significant difference in the overall incidence of healing, 1 month after surgery (chi 1(2) = 0.07; P > 0.9). In the closed group, healing was obtained by primary intention, leaving a linear surgical scar in 84% of the cases (SE(p) = 5.7%; 95% CI = 72.8-95.2%). Hospitalization and the need for analgesia and dressing changes were reduced by 40-60%. CONCLUSIONS: Primary closure of acute superficial abscesses was associated with an improved outcome in terms of duration and quality of healing, postoperative pain, length of hospitalization, nursing care and, by implication, cost, and may be recommended as an alternative treatment that is superior to the orthodox technique.

Abscess↗
PubMed1997

Initial rate of healing predicts complete healing of venous ulcers.

BACKGROUND: Venous ulcers represent a clinical problem with considerable morbidity, especially in the elderly population. Standard treatment is the use of leg compression bandages to improve the underlying venous hypertension, but not every ulcer heals in a timely fashion with this treatment modality. Methods are needed to predict the outcome of standard treatment as soon as possible to institute alternative therapy. OBJECTIVE: To prospectively study the rate of healing in a group of elderly patients with venous ulcers, based on a previously described equation that takes into account the size and perimeter of the ulcer. METHODS: We studied by computerized planimetry 15 elderly patients with venous ulcers treated with leg compression bandages for up to 24 weeks or until complete healing. We determined weekly healing rate by comparing ulcer size at each visit to initial baseline size (baseline-adjusted healing rate). Also, we used a novel way to calculate the healing rate at a given week by taking the mean of all previous healing rates between each visit (mean-adjusted healing rate). RESULTS: When using the baseline-adjusted healing rate, we noted what we describe as a healing rate instability from week to week, which decreases the ability to predict complete healing. However, the mean-adjusted healing rate allowed us to predict complete healing as early as 3 weeks from starting therapy (P<.001). CONCLUSION: In this prospective study of elderly patients with venous ulcers, we describe a novel and more powerful method for predicting complete healing of venous ulcers with compression therapy alone.

Administration, Cutaneous↗