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171.
OBJECTIVE: To determine whether the investment in postgraduate education and training places patients at risk for worse outcomes and higher costs than if medical and surgical care was delivered in nonteaching settings. SUMMARY BACKGROUND DATA: The Veterans Health Administration (VA) plays a major role in the training of medical students, residents, and fellows. METHODS: The database of the VA National Surgical Quality Improvement Program was analyzed for all major noncardiac operations performed during fiscal years 1997, 1998, and 1999. Teaching status of a hospital was determined on the basis of a background and structure questionnaire that was independently verified by a research fellow. Stepwise logistic regression was used to construct separate models predictive of 30-day mortality and morbidity for each of seven surgical specialties and eight operations. Based on these models, a severity index for each patient was calculated. Hierarchical logistic regression models were then created to examine the relationship between teaching versus nonteaching hospitals and 30-day postoperative mortality and morbidity, after adjusting for patient severity. RESULTS: Teaching hospitals performed 81% of the total surgical workload and 90% of the major surgery workload. In most specialties in teaching hospitals, the residents were the primary surgeons in more than 90% of the operations. Compared with nonteaching hospitals, the patient populations in teaching hospitals had a higher prevalence of risk factors, underwent more complex operations, and had longer operation times. Risk-adjusted mortality rates were not different between the teaching and nonteaching hospitals in the specialties and operations studied. The unadjusted complication rate was higher in teaching hospitals in six of seven specialties and four of eight operations. Risk adjustment did not eliminate completely these differences, probably reflecting the relatively poor predictive validity of some of the risk adjustment models for morbidity. Length of stay after major operations was not consistently different between teaching and nonteaching hospitals. CONCLUSION: Compared with nonteaching hospitals, teaching hospitals in the VA perform the majority of complex and high-risk major procedures, with comparable risk-adjusted 30-day mortality rates. Risk-adjusted 30-day morbidity rates in teaching hospitals are higher in some specialties and operations than in nonteaching hospitals. Although this may reflect the weak predictive validity of some of the risk adjustment models for morbidity, it may also represent suboptimal processes and structures of care that are unique to teaching hospitals. Despite good quality of care in teaching hospitals, as evidenced by the 30-day mortality data, efforts should be made to examine further the structures and processes of surgical care prevailing in these hospitals.  相似文献   
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The pathophysiology of cyanotic/apnoeic episodes in preterm infants was investigated using overnight tape recordings of beat-to-beat arterial oxygen saturation (SaO2), plethysmographic waveforms from the oximeter, breathing movements and nasal airflow. Recordings were made in 16 preterm infants with recurrent cyanotic episodes of unknown cause that had received stimulation or resuscitation, and 15 preterm controls, matched for birth weight, post-conceptional and postnatal age. The recordings were analysed for baseline SaO2, the number of hypoxaemic episodes (SaO2 < or = 80% for > or = 4 s) and the breathing patterns associated with each episode. There was a significant difference in the total number of hypoxaemic episodes between patients and controls (520 versus 100; p < 0.01), but no difference was found for mean baseline SaO2 (98.6 versus 99.0%; p > 0.05). The mean duration of each hypoxaemic episode in the patients was 9.5 s compared with 5.8 s in the controls (p < 0.01). Although most hypoxaemic episodes (62 and 76%) were associated with pauses in breathing movements, a proportion (8 and 18%, respectively) occurred despite continuous airflow and breathing movements in both patients (6 of 16) and preterm controls (2 of 15). The rate of decrease in SaO2 was significantly more rapid during these latter hypoxaemic episodes than during episodes associated with isolated apnoeic pauses (8.5 versus 3.2% per second, p = 0.02). Preterm infants with cyanotic episodes have increased numbers of clinically unapparent hypoxaemic episodes, some of which have continued ventilation and rapid desaturation. The pathogenesis of these episodes warrants further investigation.  相似文献   
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A case of familial heart myxoma in 4 members of one family combined with myxomic (hamartomatous) syndrome is reported. The tumor in a proband was characterized with a multiple growth in various heart chambers. Five operations were made in the proband for 16 years and seven myxomas of different locations were removed. Myxomas originating from the endocardium of the interatrial septum oval hole were removed in 3 members of his family. The case confirms the conception of heart myxoma origin from endothelial hamartia of the endocardium.  相似文献   
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The patients suffering from hypertonic nephritis were examined for renal hemodynamics, the activity of the renin-angiotensin-aldosterone system (RAAS), excretion of PGE2 and PGF2 alpha, and for a number of the parameters of water-electrolyte homeostasis. In A series, the patients suffering from latent and hypertonic nephritis (n = 11 in each group) were compared. In B series, two groups of the patients (n = 13 in each group) suffering from hypertonic nephritis associated with moderate or grave arterial hypertension were compared. The patients under comparison belonging to A and B series did not differ as regards the sex, age, nephritis standing, serum creatinine or proteinuria. As compared with the patients suffering from latent nephritis (A series), the patients with hypertonic nephritis showed a lower effective renal plasma flow, a greater resistance of the renal vessels, lesser PGE2 secretion, and a higher serum sodium concentration. As compared with the patients suffering from moderate hypertension (B series), the patients with associated hypertonic nephritis and grave hypertension demonstrated a higher resistance of the renal vessels, a higher activity of plasma renin, a larger concentration of plasma aldosterone and its excretion with urine, as well as a greater volume of the circulating blood. It is assumed that the development of arterial hypertension associated with hypertonic nephritis may be caused by renal hemodynamics deterioration, by relative activation of the renin-angiotensin system, inhibition of the depressor prostaglandin system and sodium retention. The progression of hypertension may be related to further deterioration of renal hemodynamics attended by RAAS activation and hypervolemia.  相似文献   
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