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31.
OBJECTIVE: This study was undertaken to assess the safety of trial of labor after previous cesarean delivery. STUDY DESIGN: Retrospective cohort study of 308,755 Canadian women with previous cesarean delivery between 1988 and 2000. Occurrences of in-hospital maternal death, uterine rupture, and other severe maternal morbidity were compared between women with a trial of labor and those with an elective cesarean section. RESULTS: Rates of uterine rupture (0.65%), transfusion (0.19%), and hysterectomy (0.10%) were significantly higher in the trial-of-labor group. Maternal in-hospital death rate, however, was lower in the trial-of-labor group (1.6 per 100,000) than in the elective cesarean section group (5.6 per 100,000). The association between trial of labor and uterine rupture was stronger in low volume (<500) than in high volume (> or =500 births per year) obstetric units. CONCLUSION: Trial of labor is associated with increased risk of uterine rupture, but elective cesarean section may increase the risk of maternal death.  相似文献   
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OBJECTIVE: This study examines the incidence and factors associated with the failure of homograft valves and identifies those factors that are modifiable. METHODS: From 1990 to 2001, 96 homograft valves were implanted in the right ventricular outflow tract of 83 children (mean age 5.1 +/- 5.6 years). Clinical and blinded serial echocardiographic follow-up was performed on all 90 valves in the 77 survivors. RESULTS: Eighteen homograft valves were replaced as the result of pulmonary insufficiency (3), stenosis (9), or both (6). Freedom from reoperation was 71% at 9 years (95% confidence interval, 58%-84%). Forty-eight valves developed progressive pulmonary insufficiency of at least 2 grades, 26 valves developed transvalvular gradients of 50 mm Hg or greater, and 14 of these valves were also insufficient. The freedom from echocardiographic failure (progressive pulmonary insufficiency >or=2 grades or >or=50 mm Hg gradient) was only 27% at 5 years (95% confidence interval, 17%-37%). In a multivariate analysis (Cox regression), use of an aortic homograft (P =.001) and short antibiotic preservation time (P =.04) were associated with reoperation. Younger age (P =.01), ABO mismatch (P =.04), and diagnosis (P =.005) were associated with echocardiographic failure. In the subanalysis of patients with human leukocyte antigen typing, age (P =.002), aortic homograft (P =.04), and human leukocyte antigen-DR mismatch (P =.03) were associated with echocardiographic valve failure. CONCLUSION: Many homografts rapidly become insufficient and require replacement. In our analysis of both reoperation and echocardiographic failure, several immunologic factors are consistently associated with homograft failure. Matching for human leukocyte antigen-DR, blood group, and avoiding short preservation times (thus minimizing antigenicity) offers the potential to extend the life of these valves.  相似文献   
34.

OBJECTIVE:

To ascertain the variation in asthma management practices among paediatricians and family physicians to determine how to improve care.

DESIGN:

Questionnaire study of paediatricians and family physicians that focused on the use of beta2-agonists, inhaled corticosteroids, patient asthma education, quantitative measurements of airflow and diagnostic investigations for asthma. Case scenarios were used in the questionnaire.

RESULTS:

The response rate was 66% (415 of 632) among paediatricians and 42% (1156 of 2750) among family physicians. In general, both groups followed consensus guidelines. There were some differences in management practices among paediatricians and family physicians. Paediatricians were more likely to develop an action plan and less likely to use xanthines or inhaled anticholinergic agents. However, family physicians were more likely to use spirometry or home peak expiratory flow rates to make a diagnosis of asthma.

CONCLUSION:

Family physicians and paediatricians require a different focus on educational interventions to improve the care of children with asthma.  相似文献   
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Four cases of a rare atypical fetal heart pattern obtained during the oxytocin challenge test are described. In all cases, there were marked oligohydramnios and fetal growth retardation with a severely compromised fetus, and in 3 cases the fetuses died.  相似文献   
38.
Objectives: To examine the utility of clinical findings, laboratory markers and X‐ray radiographs (X‐ray) in the assessment of children presenting with an acute non‐traumatic limp. Methods: A retrospective review of all children who received hip X‐rays over a 2 year period in the Children's Emergency Department, Starship Children's Hospital, Auckland, New Zealand. Children were identified from the radiology database and clinical notes reviewed. Children aged 0–12 years old were included if the limp was acute (less than 2 weeks of duration) with no history of trauma. X‐rays were reported by a consultant paediatric radiologist. Univariate and multivariate analysis was performed to determine predictors of osteomyelitis and septic arthritis. Receiver operator curves were used to assess the optimum cut‐off points for C reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white cell count (WCC). Results: A total of 350 patients were enrolled. There were 21 (6%) abnormal X‐rays . Fever, non‐weight bearing, raised white cell count, raised erythrocyte sedimentation rate and raised CRP were all associated with increased risk of septic hip or osteomyelitis. The optimum inflammatory marker cut‐off was a CRP of 12 with a sensitivity of 87% and specificity of 91%. Conclusion: In acute non‐traumatic limp, X‐rays of the hips diagnose slipped upper femoral epiphysis, as such they should be routinely used from the age of 9 years upwards. Below this age they are of little value. Inflammatory markers have utility in risk‐stratifying children and selecting a group in whom to proceed with definitive tests to exclude osteomyelitis or septic hip. Children with a short history and minimal symptoms can be managed with appropriate follow up and no investigations.  相似文献   
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Motor racing is perceived as a dangerous sport but few data are available on the incidence and nature of injuries sustained. The medical service requirement at one regional motor racing circuit was assessed by determining the incidence of injuries, the medical interventions required and the need for hospital referral and admission over a 5-year period. Five hundred and twenty-one patients, including support staff and spectators, attended the medical centre, of whom 14% were referred to hospital and 4% required admission. Each competitor had a 4% chance of requiring on-circuit medical attention, 0.6% chance of hospital referral and 0.17% chance of admission per race. Most major accidents involved more than two drivers. Twenty sustained major trauma including five pelvic fractures and two intraabdominal haemorrhages. Emergency intervention included intubation and ventilation in five. There were three deaths from a total of 9000 competitors (mortality rate 0.033%). This study shows that despite the nature of the sport, the mortality rate remains low with prompt skilled medical intervention. Medical personnel should include those competent in dealing with minor medical complaints as well as those with advanced airway management and resuscitation skills. Although national motor sport guidelines recommend a minimum of two attending doctors this would have been insufficient for multivehicle accidents.  相似文献   
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