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Biomedical subjects

R Bell

Publications and source records attributed to R Bell.

At least 55 records · Page 3Linked to original sources
PubMed2000

Estimation of fetal weight by ultrasound prior to 33 weeks gestation.

The aim of this study was to develop an accurate formula for the ultrasonic prediction of fetal weight for infants < 33 weeks gestational age and < or = 1500 g birthweight. The subjects comprised live births free of lethal malformations or chromosomal anomalies, < 33 weeks gestational age and with birthweights +/- 1500 g born in the Royal Women's Hospital between January 1990 and March 1996. All subjects had accurate gestational age confirmed by ultrasound prior to 20 weeks gestation and ultrasound measurements within 72 hours of birth of biparietal diameter (BPD), femur length (FL) and abdominal circumference (AC). A formula with the highest explained variance was computed by linear regression analysis using the three fetal variables in various combinations from 54 infants born between January 1990 and December 1993. The optimal formula was: Log(10)birthweight = 0.714627 + 0.077362.AC + 0.058758.BPD + 0.287037.FL - 0.011274.AC.FL. The new formula was more accurate compared with existing formulae when tested in a separate cohort of 39 infants born between January 1994 and March 1996.

Cohort Studies↗
PubMed2000

Antenatal exercise and birthweight.

Does strenuous antenatal exercise reduce birthweight? Does reducing maternal exercise increase birthweight? What to advise about exercise during pregnancy? We recruited 117 women who intended to exercise 5 or more times weekly during pregnancy to a study of whether reducing the amount of maternal exercise during pregnancy is associated with an increase in birthweight. Only 61/117 (52%) of women agreed to be randomised to either continue or to reduce (to 3 or fewer sessions of exercise weekly) their intended pregnancy exercise program. Most women who refused randomisation did not want to risk being asked to reduce their exercise during pregnancy. Within the randomised trial, there was no statistically significant difference between the mean birthweight of babies born to women who continued and those who reduced their intended exercise program. The high rate of refusal of randomisation limits the power of the study to find a difference in birthweight, limits the generalisability of the results and shows that many women intending to exercise at this level during pregnancy have an uncompromising attitude to exercise.

Birth Weight↗
PubMed2000

Appropriateness of the decision to transfer nursing facility residents to the hospital.

OBJECTIVES: To develop and test a standardized instrument, the purpose of which is to assess (1) whether skilled nursing facilities (SNFs) transfer residents to emergency departments (ED) inappropriately, (2) whether residents are admitted to hospitals inappropriately, (3) and factors associated with inappropriate transfers. DESIGN: A structured implicit review (SIR) of medical records. SETTING AND PARTICIPANTS: Using nested random sampling in eight community SNFs, we identified SNF and hospital records of 100 unscheduled transfers to one of 10 hospitals. MEASUREMENTS: Seven trained physician reviewers assessed appropriateness using a SIR form designed for this study (2 independent reviews per record, 200 total reviews). We measured interrater reliability with kappa statistics and used bivariate analysis to identify factors associated with assessment that transfer was inappropriate. RESULTS: In 36% of ED transfers and 40% of hospital admissions, both reviewers agreed that transfer/admit was inappropriate, meaning the resident could have been cared for safely at a lower level of care. Agreement was high for both ED (percent agreement 84%, kappa .678) and hospital (percent agreement 89%, kappa .779). When advance directives were considered, both reviewers rated 44% of ED transfers and 45% of admissions inappropriate. Factors associated with inappropriateness included the perceptions that: (1) poor quality of care contributed to transfer need, (2) needed services would typically be available in outpatient settings, and (3) the chief complaint did not warrant hospitalization. CONCLUSIONS: Inappropriate transfers are a potentially large problem. Some inappropriate transfers may be associated with poor quality of care in SNFs. This study demonstrates that structured implicit review meets criteria for reliable assessment of inappropriate transfer rates. Structured implicit review may be a valuable tool for identifying inappropriate transfers from SNFs to EDs and hospitals.

Advance Directives↗
PubMed2000

Relative cost of autologous red cell salvage versus allogeneic red cell transfusion during abdominal aortic aneurysm repair.

The costs of washed autologous red cell concentrate obtained by intraoperative red cell salvage were compared to the costs of allogeneic packed red cell transfusion during 110 consecutive abdominal aortic aneurysm repairs. The mean volume of scavenged blood during elective procedures was 1350 ml (range 350 to 6675 ml, n = 90) and emergency procedures 2750 ml (range 750 to 9400 ml, n = 20). The mean volume of processed (washed) blood returned during elective repairs was 759 ml (range 150 to 2900 ml, n = 51) and emergency repairs 1117 ml (range 0 to 4100 ml, n = 20). During elective repairs, the cost of routine autologous red cell salvage ($151 per 285 ml unit) was only slightly greater than the estimated cost of cross-matched, leucocyte-reduced, allogeneic blood ($143 per 285 ml unit). During emergency repairs, washed autologous red cells ($83 per 285 ml unit) were less expensive than allogeneic packed red cells. These findings indicate that, compared with the use of allogeneic packed red cells, red cell salvage during emergency abdominal aortic aneurysm repair can be justified on an economic basis alone, and that routine red cell salvage during elective repair can achieve the benefits of autologous blood at little extra cost to the community.

Aged↗
PubMed1999

Underuse of cardiac procedures: do women, ethnic minorities, and the uninsured fail to receive needed revascularization?

BACKGROUND: Women, ethnic minorities, and uninsured persons receive fewer cardiac procedures than affluent white male patients do, but rates of use are crude indicators of quality. The important question is, Do women, minorities, and the uninsured fail to receive cardiac procedures when they need them? OBJECTIVE: To measure receipt of necessary coronary artery bypass graft (CABG) surgery and percutaneous transluminal coronary angioplasty (PTCA) overall; by patient sex, ethnicity, and payer status; and by availability of on-site revascularization. DESIGN: Retrospective, randomized medical record review. SETTING: 13 of the 24 hospitals in New York City that provide coronary angiography. PATIENTS: 631 patients who had coronary angiography in 1992 and met the RAND expert panel criteria for necessary revascularization. MEASUREMENTS: The percentage of patients who had CABG surgery or PTCA was measured, as were variations in use rates by sex, ethnic group, insurance status, and availability of on-site revascularization. Clinical and laboratory data were retrieved from medical records to identify patients who met the panel criteria for necessary revascularization. Receipt of revascularization was determined from state reports, medical records, and information provided by cardiologists. RESULTS: Overall, 74% (95% CI, 71% to 77%) of patients who met the panel criteria for necessary revascularization had CABG surgery or PTCA (underuse rate, 26%). No differences were found in use rates by patient sex, ethnic group, or payer status, but hospitals that provided on-site revascularization had higher use rates (76% [CI, 74% to 79%]) than hospitals that did not provide it (59% [CI, 56% to 65%]) (P < 0.01). In hospitals that did not provide on-site revascularization, uninsured patients were less likely to have revascularization recommended to them (52% [CI, 32% to 78%]); rates of recommendation for patients with private insurance, Medicare, and Medicaid were 82%, 91%, and 75%, respectively (P = 0.026). CONCLUSIONS: Although revascularization procedures are substantially underused, no variations in rate of use by sex, ethnic group, or payer status were seen among patients treated in hospitals that provide CABG surgery and PTCA. However, underuse was significantly greater in hospitals that do not provide these procedures, particularly among uninsured persons.

Angioplasty, Balloon, Coronary↗
PubMed1999

A multi-institutional study of factors associated with fetal death in injured pregnant patients.

HYPOTHESIS: Factors associated with fetal death in injured pregnant patients are related to increasing injury severity and abnormal maternal physiologic profile. DESIGN: A multi-institutional retrospective study of 13 level I and level II trauma centers from 1992 to 1996. MAIN OUTCOME MEASURE: Fetal survival. RESULTS: Of 27,715 female admissions, there were 372 injured pregnant patients (1.3%); 84% had blunt injuries and 16% had penetrating injuries. There were 14 maternal deaths (3.8%) and 35 fetal deaths (9.4%). The population suffering fetal death had higher injury severity scores (P<.001), lower Glascow Coma Scale scores (P<.001), and lower admitting maternal pH (P = .002). Most women who lost their fetus arrived in shock (P = .005) or had a fetal heart rate of less than 110 beats/min at some time during their hospitalization (P<.001). An Injury Severity Score greater than 25 was associated with a 50% incidence of fetal death. Placental abruption was the most frequent complication, occurring in 3.5% of patients and associated with 54% mortality. Cardiotrophic monitoring to detect potentially threatening fetal heart rates was performed on only 61% of pregnant women in their third trimester. Of these patients, 7 had abnormalities on cardiotrophic monitoring and underwent successful cesarean delivery. CONCLUSIONS: Fetal death was more likely with greater severity of injury. Cardiotrophic monitoring is underused in injured pregnant patients in their third trimester even after admission to major trauma centers. Increased use of cardiotrophic monitoring may decrease the mortality caused by placental abruption.

Female↗
PubMed1999

Banff schema for grading liver allograft rejection: utility in clinical practice.

An accurate and functional system for grading acute liver allograft rejection is important for patient management, research, and communication. The Banff schema is a consensus document designed to provide an internationally accepted standard for this purpose. The aim of this study is to determine if application of the Banff schema would significantly alter the grading of acute liver allograft rejection compared with the Birmingham system. One hundred twenty-four post-liver transplantation biopsies performed by the Western Australian Liver Transplantation Service between 1992 and 1997 were retrospectively analyzed by a pathologist and a hepatologist. Each was supplied with a brief clinical history before applying the Banff and Birmingham criteria. Results were compared with each other and to the diagnosis made at the time of the biopsy, which was based on the European grading system. Rejection was diagnosed by the reviewers in 61 of 124 biopsy specimens according to the criteria of Snover. The Banff schema and Birmingham system agreed on the grade of rejection in 22 of the 61 biopsy specimens. The Banff schema elevated the grade of rejection in 39 specimens by an increment of one. In no instance did the Banff schema reduce the grade. Comparison between the Banff schema and diagnosis made at the time of biopsy showed agreement in 39 specimens, whereas the Banff schema elevated the grade in 15 specimens and reduced the grade in 23 specimens. In comparison to the Birmingham system, the Banff schema elevated the grade of liver allograft rejection in the majority of biopsy specimens, and this has the potential to alter clinical management with the adoption of the Banff schema or if the systems are used interchangeably.

Adolescent↗
PubMed1999

Continuities and changes: teenage smoking and occupational transition.

Rates of cigarette smoking among young people in the U.K. remain high and may be increasing. However, few studies have explored smoking behaviour during the mid- to late teens. This paper reports the third wave of a longitudinal study that followed 106 15-year-olds from their last compulsory year at school for 22 months. Using a mixture of qualitative and quantitative methods, the study shows that this is a period of considerable flux in smoking behaviour. Becoming a regular smoker is not a straightforward progressive process. The role of friendship groups and social context is highlighted. Smoking prevention programmes should be developed to meet the needs of young people in this transitional period.

Adolescent↗
PubMed1999

Early carotid endarterectomy in selected stroke patients.

Although there are several reports suggesting the safety of performing carotid endarterectomy (CE) within 4 weeks (early) of a nondisabling stroke, at many institutions it is not standard practice. Benefits of early surgery may include reduction in the number of strokes or carotid occlusions during the time between stroke and surgery, as well as a reduction in the cost of medical care due to the elimination of interval anticoagulation and close follow-up. This review examines the outcomes of early CE in selected patients after a nondisabling stroke. A total of 1065 CEs were performed between November 1991 and April 1998. Seventy-five patients were identified by computerized hospital record and office chart review as having CE after a nondisabling stroke. Criteria for early surgery included 1) nondisabling stroke ipsilateral to a carotid stenosis >50%, 2) neurological stability, and 3) no evidence of hemorrhagic stroke or significant cerebral edema by CT/MRI evaluation. This review suggests that early CE can be performed in selected patients with an acceptable perioperative morbidity and mortality.

Aged↗
PubMed1999

Underuse and overuse of diagnostic testing for coronary artery disease in patients presenting with new-onset chest pain.

PURPOSE: To determine the extent of overuse and underuse of diagnostic testing for coronary artery disease and whether the socioeconomic status, health insurance, gender, and race/ethnicity of a patient influences the use of diagnostic tests. SUBJECTS AND METHODS: We identified patients who presented with new-onset chest pain not due to myocardial infarction at one of five Los Angeles-area hospital emergency departments between October 1994 and April 1996. Explicit criteria for diagnostic testing were developed using the RAND/University of California, Los Angeles, expert panel method. They were applied to data collected by medical record review and patient questionnaire. RESULTS: Of the 356 patients, 181 met necessity criteria for diagnostic cardiac testing. Of these, 40 (22%) failed to receive necessary tests. Only 7 (3%) of the 215 patients who received some form of cardiac testing had tests that were judged to be inappropriate. Underuse was significantly more common in patients with only a high school education (30% vs 15% for those with some college, P = 0.02) and those without health insurance (34% vs 15% of insured patients, P = 0.01). In a multivariate logistic regression model, only the lack of a post-high school education was a significant predictor of underuse (odds ratio 2.2, 95% confidence interval 1.0 to 4.4). CONCLUSION: Among patients with new-onset chest pain, underuse of diagnostic testing for coronary artery disease was much more common than overuse. Underuse was primarily associated with lower levels of patient education.

Adult↗
PubMed1999

An imbalance of dietary essential fatty acids retards behavioral development in mice.

This study investigated the effects of an imbalance of dietary essential fatty acids on behavioral development. Pregnant and lactating mice were fed a diet with a very low (n-6):(n-3) ratio, in which the (n-6) and (n-3) fatty acids were provided solely as linoleic acid [LA, 18:2 (n-6)] and very high levels of docosahexaenoic acid [DHA, 22:6 (n-3)], respectively. The development of the pups was compared with that of pups of similar age and body weight that had been undernourished by rearing in large litters. On the day of conception (Day 0), pregnant B6D2F1 mice were assigned randomly to one of four dietary groups. Two of these groups were fed lab chow, and after birth varied in terms of the number of pups per litter, large (LgLIT) = 12, and normal (NmLIT) = 6. The remaining two groups both had six pups per litter, but varied in dietary (n-6):(n-3) ratio, low (LoRAT = 0.32) and normal (NmRAT = 4.0). On Day 32 postconception both the LgLIT and the LoRAT groups had lower body weights and were behaviorally retarded relative to their respective NmLIT and NmRAT controls. Nonetheless, there was some sparing of function in both these groups, as they were behaviorally advanced relative to younger animals of a similar body weight. These findings show that the growth retardation seen in the offspring of dams fed a diet with a low (n-6):(n-3) ratio and very high levels of DHA is accompanied by behavioral retardation of a similar degree to that seen in malnourished pups.

Animals↗
PubMed1999

Lack of effect of the 5-HT(1A) receptor antagonist WAY-100635 on murine agonistic behaviour.

The present study examined the influences of the selective 5-HT1A receptor antagonist, WAY-100635, on the social and agonistic behavior exhibited by male resident mice during encounters with unfamiliar intruder conspecifics. Acute administration of WAY-100635 (0.01-1.0 mg/kg sc) dose dependently enhanced the duration of resident maintenance behavior, reaching statistical significance at 1.0 mg/kg. The duration of resident attend/approach behavior was reduced at 0.01 mg/kg. Drug-free intruder animals showed a reduction in the frequency and duration of attend/approach behavior when the resident mice were treated with 0.01 mg/kg WAY-100635. No other significant effects on behavior were detected for WAY-100635. A previous investigation reported that WAY-100635 induced anxiolytic-like effects in the mouse light/dark box test. In the present study, however, the level of defensive behavior of the saline-treated resident mice was too low for any further anxiolytic-like attenuation of this behavior to be observed. Therefore, no conclusions regarding the potential anxiolytic activity of WAY-100635 may be drawn from the data presented here. Current results are consistent with data for the lack of effect of WAY-100635 on rat agonistic behavior but contrast with findings for the effects of the 5-HT1A receptor antagonists (+)-WAY-100135 and SDZ 216-525 on mouse agonistic behavior.

Agonistic Behavior↗
PubMed1999

Asymptomatic carotid artery stenosis associated with peripheral vascular disease: a prospective study.

This study aimed to determine the prevalence of symptomless internal carotid artery stenosis in consecutive patients presenting with peripheral vascular disease. Duplex ultrasound screening of the carotid arteries was used to determine the degree of stenosis. Co-morbidities were recorded together with age, sex and tobacco use. Internal carotid artery stenosis of > 50% was found in 35% of patients. Among these there was > or = 70% stenosis in 18% of patients and of this group 5% had an occluded carotid vessel at first presentation. Males presented with peripheral vascular disease and associated carotid stenoses at a younger age than females. Male smokers had a higher prevalence of stenosis (P = 0.036) but all smokers had developed stenoses 3-5 years before non-smokers. Females with abdominal aortic aneurysms had a greater prevalence of carotid stenosis (P = 0.037), and male aneurysmal disease diminished stenosis prevalence (P = 0.023). Men with an elevated serum creatinine were more likely to have a stenosis (P = 0.019), but not women. The other co-morbidities were not specifically associated with carotid artery stenosis.

Adult↗
PubMed1999

The local management of soft tissue sarcoma.

Soft tissue sarcomas (STS) are rare tumors arising from the connective tissues. STS can arise at any anatomic site, can demonstrate varied behavior and prognosis, and therefore present a formidable challenge in management. The local treatment of STS demands technical complexity in the application of diagnostic tools, including pathology and imaging, as well as treatment approaches, including surgical ablation and reconstruction, radiotherapy, and, in defined cases, chemotherapy. The understanding of the management of these lesions is profoundly dependent on the multidisciplinary setting, where experience has been gained and skills are available to increase the likelihood of a successful result. Several proven options are available for optimal local management, and the choice of approach depends on the prevailing practice and resource profile of the treating center. With modern approaches, the local control rate can be expected to be at least 90% for extremity lesions, which constitute the most common STS. The experience in other anatomic sites is less favorable as a result of a combination of late diagnosis, technically difficult access sites, and possibly less familiarity with these less common presentations. The disappointing results make it all the more important for patients to be referred to a multidisciplinary setting with experience in sarcoma management to maximize the chance of successful local outcome.

Amputation, Surgical↗
PubMed1999

The theory of planned behavior and smoking cessation.

A sample of 84 smokers attending health promotion clinics in a primary care setting completed questionnaires that assessed the main constructs of the theory of planned behavior, perceived susceptibility, and past cessation attempts. Regression analyses revealed that intention to quit smoking was primarily predicted by perceived behavioral control and perceived susceptibility. At 6-month follow-up, the making of a quit attempt was predicted by intention and the number of previous quit attempts, whereas the length of the quit attempt was predicted solely by the length of the longest recent quit attempt. The results suggest that interventions should focus on perceptions of susceptibility and control to increase smokers' motivation to quit. However, further work is required to identify the social cognitive variables that ensure that initial quit attempts are translated into longer term abstinence.

Adult↗
PubMed1999

Endoscopic thoracic sympathectomy for primary palmar hyperhidrosis: intermediate term results.

BACKGROUND: The authors' experience of the efficacy and safety of endoscopic thoracic sympathectomy in the treatment of primary palmer hyperhidrosis was examined. METHODS: A retrospective study of 71 patients (126 sympathectomies) was undertaken. Data were retrieved by hospital records and telephone interview. RESULTS: Follow-up was possible for 92 sympathectomies in 53 patients. Overall, satisfactory results were achieved in 93% of patients and complications were uncommon. Compensatory hyperhidrosis was the most common complication, which occurred in 64% of patients; the trunk and feet were the most common sites. Horner's syndrome occurred in five patients, although in two it was a permanent complication. No patient expressed dissatisfaction with the procedure as a consequence of this complication. Pneumothorax occurred in 17.5% of cases, although the vast majority were incidental findings on a postoperative chest X-ray, and none required drainage. With the newer techniques of access, patient dissatisfaction with the cosmetic appearance has fallen from 27.3 to 6.4%. Overall 90% of patients said they would have the operation again, which represents a high level of patient satisfaction. CONCLUSIONS: Endoscopic thoracic sympathectomy is a safe and effective technique for primary palmer hyperhidrosis. Evolution of the technique has resulted in improvement in patient satisfaction.

Adolescent↗