Towards evidence-based guidelines for the prevention of venous thromboembolism: systematic reviews of mechanical methods, oral anticoagulation, dextran and regional anaesthesia as thromboprophylaxis.

OBJECTIVES: To assess the benefits in terms of reductions in the risks of deep vein thrombosis (DVT) and of pulmonary embolism (PE), and hazards in terms of major bleeding, of: (i) mechanical compression; (ii) oral anticoagulants; (iii) dextran; and (iv) regional anaesthesia (as an alternative to general anaesthesia) in surgical and medical patients. DATA SOURCES: Electronic databases, search of Antithrombotic Trialists' Collaboration database, contact with trialists and manufacturers. REVIEW METHODS: All trials identified as fitting the selection criteria were independently assessed. The primary outcomes were DVT, PE and major bleeding events, and proximal venous thrombosis (PVT) and fatal PE were secondary outcomes. Trials were subdivided into those that had assessed a method as the only means of thromboprophylaxis ('monotherapy') and those that had assessed the effects of adding a method to another form of thromboprophylaxis ('adjunctive therapy'). RESULTS: Mechanical compression methods reduced the risk of DVT by about two-thirds when used as monotherapy and by about half when added to a pharmacological method. These benefits were similar irrespective of the particular method used (graduated compression stockings, intermittent pneumatic compression or footpumps) and were similar in each of the surgical groups studied. Mechanical methods reduced the risk of PVT by about half and the risk of PE by two-fifths. Oral anticoagulants, when used as monotherapy, reduced the risk of DVT and of PVT by about half, and this protective effect appeared similar in each of the surgical groups studied. There was an apparently large four-fifths reduction in the role of PE, but not only was the magnitude of this reduction statistically uncertain, but also pulmonary embolism was reported by a minority of trials, so it may be subject to selection bias. Oral anticoagulant regimens approximately doubled the risk of major bleeding and appeared less effective at preventing DVT than heparin regimens, although were associated with less major bleeding. Dextran reduced the risk of DVT and of PVT by about half, again irrespective of the type of surgery, but too few studies had reported PE to provide reliable estimates of effect on this outcome. Dextran appeared to be less effective at preventing DVT than the heparin regimens studied. Dextran was associated with an increased risk of bleeding, but too few bleeds had occurred for the size of this excess risk to be estimated reliably. Compared with general anaesthesia, regional anaesthesia reduced the risk of DVT by about half, and this benefit appeared similar in each of the surgical settings studied. Regional anaesthesia was associated with less major bleeding than general anaesthesia. CONCLUSIONS: In the absence of a clear contraindication (such as severe peripheral arterial disease), patients undergoing a surgical procedure would be expected to derive net benefit from a mechanical compression method of thromboprophylaxis (such as graduated compression stockings), irrespective of their absolute risk of venous thromboembolism. Patients who are considered to be at particularly high risk of venous thromboembolism may also benefit from a pharmacological thromboprophylactic agent, but since oral anticoagulant and dextran regimens appear less effective at preventing DVT than standard low-dose unfractionated heparin or low molecular weight heparin regimens, they may be less suitable for patients at high risk of venous thromboembolism, even though they are associated with less bleeding. Whenever feasible, the use of regional anaesthesia as an alternative to general anaesthesia may also provide additional protection against venous thromboembolism. There is little information on the prevention of venous thromboembolism among high-risk medical patients (such as those with stroke), so further randomised trials in this area would be helpful.

[Risk factors of readmission in acute exacerbation of moderate-to-severe chronic obstructive pulmonary disease]. / Factores predictivos de reingreso hospitalario en la agudización de la EPOC moderada-grave.

OBJECTIVES: More effective management of chronic obstructive pulmonary disease (COPD) and improved survival of COPD patients requires a better understanding of the risk factors for exacerbation. The aim of this study was to identify factors related to readmission in patients with moderate-to-severe COPD. PATIENTS AND METHODS: Ninety patients with moderate-to-severe COPD hospitalized consecutively for acute exacerbation were studied prospectively. At discharge, the following potential predictors were assessed: clinical and spirometric variables, arterial blood gases, and respiratory muscle strength determined noninvasively. The patients were followed for a period of 3 months. Readmission for exacerbation and time intervals free of hospitalization were recorded. RESULTS: Univariate analysis showed that the presence of cor pulmonale (P<.05), long-term oxygen therapy (P<.05), hypercapnia (P<.05), and high inspiratory load--mean inspiratory airway pressure measured at the mouth exceeding 0.40 cm H2O and a pressure-time index greater than 0.25 (P<.05 for both variables)--increased the risk of hospitalization for exacerbation. Multivariate analysis showed that only cor pulmonale (P<.05) and a high pressure-time index (>0.25, P<.05) were independently related to risk of readmission. CONCLUSIONS: Cor pulmonale and a high pressure-time index are independent risk factors for hospitalization for exacerbation of moderate-to-severe COPD.

[Infrequent etiology of upper airway resistance syndrome]. / Una etiología infrecuente de síndrome de resistencia de las vías aéreas superiores.

We present the case of a thirty-eight years-old man bearing of frequent crisis of asphyxiating wakefulness and breathnessless whenever he was asleep. There also were excessive daytime sleepiness and a strong snore before every wakefulness, but not for the rest of sleep. A polysomnographic study revealed normal values in the oxygen desaturation index, minimum oxygen saturation, an sleep structure alteration with a decrease of III-IV stages, high arousals index and RDI < 5. Pharyngeal diameters measured by mean of TC were normal, but sleepiness degree detected in the Epworth scale was high. Nasal fiberoptic endoscopy study allowed to see a swinging epiglottis that closed totally the upper airway during forced inspiration. The lack of desaturation episodes with numerous wakefulness along the sleep and excessive daytime sleepiness drove to the diagnosis of upper airway resistance syndrome (UARS). Treatment whit C-PAP just provoked an impairment in symptoms, but a CO2-laser partial epiglottectomy improved them. Patophysiological aspects of UARS, as well as its follow-up and therapeutic alternatives are commented.

Interaction of social skill and general mental ability on job performance and salary.

Job and organizational changes have promoted the importance of social skill at work, yet research in this area has been limited. The authors investigated the interaction between social skill and general mental ability (GMA) in the explanation of job performance and salary, controlling for personality and demographic characteristics. The results indicated that the relationships between social skill and job performance were stronger among workers high than low in GMA. In a similar manner. the relationships between GMA and job performance were stronger among workers high than low in social skill. The interaction on salary indicated that increases in social skill (or GMA) for high-GMA (or social skill) individuals were associated with higher salary levels. It is interesting, however, that increases in social skill (or GMA) for those low in GMA (or social skill) contributed to lower salaries. Implications of these results and directions for future research are discussed.

Kyphoscoliosis ventilatory insufficiency: noninvasive management outcomes.

OBJECTIVE: To determine the effects on symptoms, pulmonary function, sleep, and other clinical variables of treating kyphoscoliosis-associated chronic alveolar hypoventilation with nocturnal nasal ventilation. DESIGN: Sixteen patients with kyphoscoliosis were treated with nocturnal nasal ventilation delivered by volume-cycled (seven patients) and pressure-cycled (nine patients) ventilators. Dyspnea, morning headaches, fatigue, hypersomnolence, and perceived sleep quality were assessed. RESULTS: All pretreatment symptoms improved significantly with nasal ventilation. Likewise, PaO2 (mm Hg), PaO2/FlO2, PaCO2 (mm Hg), pH, and forced vital capacity (in milliliters and as a percentage of predicted normal) significantly improved with treatment. Maximum inspiratory pressures and maximum expiratory pressures also significantly increased. Tidal volumes increased significantly and breathing frequency decreased (not significant). Although perceived sleep quality improved, as well as sleep oxyhemoglobin saturation, there was no significant change in sleep architecture. Hospitalization days for respiratory difficulties also decreased from 10.9 +/- 13.3 days in the 6 mo before intermittent positive-pressure ventilation to 0 days during the first 6 mo of treatment. CONCLUSIONS: Although not apparently affecting sleep architecture, nocturnal nasal ventilation can significantly improve nocturnal and daytime blood gases, pulmonary function, and symptoms of hypoventilation for patients with severe kyphoscoliosis.

An epidemiological needs assessment of carotid endarterectomy in an English health region. Is the need being met?

OBJECTIVE: To compare the level of provision of carotid endarterectomy (an intervention of proved efficacy for prevention of stroke in patients with symptomatic high grade carotid artery stenosis) with estimates of need. DESIGN: Comparison of regional, district, and age-sex specific operation rates derived from hospital episode statistics with estimates of need based on demographic and epidemiological data; interviews with regional vascular surgeons and a joint provider-purchaser workshop to discuss implications. SETTING: Former Wessex Regional Health Authority, 1991-2 to 1995-6. SUBJECTS: All residents covered by Wessex region treated for carotid artery reconstruction. MAIN OUTCOME MEASURES: Regional, district, and age-sex operation rates as three year average 1993-6 (use) compared with respective estimates of need for carotid endarterectomy among those who presented with symptomatic carotid disease-transient ischaemic attack or minor stroke. RESULTS: The operation rate more than doubled between 1991-2 and 1995-6, from 35 to 89 per million population, compared with an estimated level of need in the region's general population of 153 per million population (transient ischaemic attack 77, minor stroke 76). The ratio of use to need was 0.47 (95% confidence interval 0.4 to 0.54); district ratios were 0.28 (0.19-0.38) to 0.81 (0.62 to 1.06). The annual use:need ratio rose over the three years 1993-6 from 0.38 to 0.59. Use:need ratios were lower in elderly and female patients. Providers were keen to develop guidelines for referral and to increase access to diagnostic facilities; purchasers were more reluctant, given the limited impact of this intervention on the incidence of stroke and the relatively high cost of the operation. CONCLUSION: Although treatment rates increased in Wessex there is still unmet need. Further research is needed to determine the referral pathways of patients with symptomatic carotid disease for diagnosis and operation and to evaluate strategies to improve access to diagnostic facilities.

What do health authorities think of population based health outcome indicators?

OBJECTIVES: To determine the role of population based indicators of health outcome in local health outcome assessments; the constraints of using such indicators; how they could be made more useful; and whether health authorities had developed their own indicators of health outcome. DESIGN: A structured telephone interview with representatives of 91 of the 100 English health authorities. RESULTS: Interviewees, asked to give details on two clinical areas in which population health outcome assessments had been of most value, nominated 147 examples in over 30 clinical areas. They chose 50 (34%) of the examples because of an outlying national indicator, and 20 (14%) because of local variations in a national indicator. The main perceived constraints in the use of population based indicators of health outcome were: data validity and timeliness; the attributability of these health outcomes to the quality of health care; the difficulties of changing clinical behavior; and organisational change within health authorities. To make these indicators more useful interviewees wanted an increased use of process indicators as proxies for health outcome, indicator trend data, and indicator comparisons of districts with similar population structures. Some recent publications have started to consider some of these issues. 27 (30%) health authorities had developed their own indicators, mostly provider based process indicators. 10 of these used their own indicators to manage the performance of local provider units. CONCLUSIONS: Population based indicators of health outcome had an important role in prompting districts to undertake population health outcome assessments. Health authorities also used these indicators to examine local variations in health outcome. They helped to highlight areas for further investigation, initiated data validation, and enabled the monitoring of changes to services. Comparative population based indicators of health outcome may have an increasing part to play in assessing the performance of health authorities.

The provision of renal replacement therapy for adults in England and Wales: recent trends and future directions.

We assessed the level of provision of renal replacement therapy for adults in England and Wales. All autonomous main renal units in England (n = 52) and Wales (n = 5) were surveyed in 1996. Data for England were compared to the 1993 National Renal Review. The acceptance rate in England 1995 was 82 (80-85) per million population (p.m.p.) compared with 67 (65-70) p.m.p. in 1991-2. The rate in 1995 in Wales was 109 (98-122) p.m.p. The prevalence rate in England was 476 p.m.p. at end-1995 compared to 393 p.m.p. in 1993, in Wales it was 487 p.m.p. The number of main renal units in England did not rise between 1993 and 1995; capacity was increased by use of more treatment shifts and temporary haemodialysis stations, and by opening more satellite units. The main growth was in hospital haemodialysis. There was an uneven geographical distribution of services. Patients accepted were older with more comorbidity. The use of better-quality processes of dialysis increased. The steady-state position for RRT will not be reached for over a decade. Health authorities will face continued pressure to fund increases in quantity and quality improvements. A stronger evidence base of the effectiveness of therapies, and a national registry to monitor the equity and cost-effectiveness of services are needed.

[Exophytic renal angiolipoma versus retroperitoneal liposarcoma]. / Angiomiolipoma renal exofítico versus liposarcoma retroperitoneal.

OBJECTIVE: To report a case of exophytic renal angiomyolipoma mimicking a retroperitoneal liposarcoma on magnetic resonance imaging. METHODS: A large, palpable abdominal mass was incidentally discovered during routine physical examination in a 61-year-old, hypertensive woman. A CT scan disclosed a retroperitoneal mass, 17 cm in diameter, adjacent to the kidney. The MRI findings were diagnostic of liposarcoma. The tumor was resected en bloc. RESULTS: The histopathological findings demonstrated angiomyolipoma. CONCLUSIONS: Exophytic angiomyolipoma can mimic retroperitoneal liposarcoma on MRI.

[Recurrent acute pancreatitis caused by ampullar intestinal duplication filled with calculi]. / Pancreatitis aguda recurrente por duplicación intestinal ampular repleta de cálculos.

OBJECTIVES: Anatomical anomalies are recognised but rare causes of acute pancreatitis. We report a case or a 33-year-old woman with recurrent attacks of acute pancreatitis associated with a ampullar intestinal duplication. MATERIAL AND METHOD: This patient was clinically studied, and a barium contrast study of the duodenum showed a filling defect in the second part of the duodenum, that was thought to be a periampullary lipoma. Endoscopic retrograde cholangiopancreatography was scheduled, but cannulation of the papillary orifice failed. RESULTS: Laparotomy and surgical resection of the lesion were performed. Pathological study of the specimen revealed a duodenal duplication filled with multiple calculi. CONCLUSION: This entity should be considered among the lesions that can cause recurrent acute pancreatitis.

Alteration in female sex hormones: their effect on oral tissues and dental treatment.

This article will discuss and describe the various oral manifestations that occur during the life cycles of the female when there is an alteration in the sex hormones--puberty, menstruation, pregnancy, and menopause. The effect of oral contraceptives on the oral tissues and dental treatment will also be discussed.

The age context of performance-evaluation decisions.

Organizational demography contends that demographic characteristics of individuals, examined at individual, dyadic, group, and organizational levels of analysis, exert significant effects on organizational processes. The purpose of this article was to test the contextual effects created by the interaction of work-group age composition and supervisor age on supervisor evaluations of subordinate performance. Two competing models of age demography were tested. The similarity model predicts that supervisors similar in age to the work group they supervise will issue generally higher performance ratings. The dissimilarity model, developed in this article, predicts the opposite. Support was indicated for the dissimilarity model. Implications of the results are discussed.

Measurement of gingival crevicular fluid conductivity, in vivo.

It has been shown that the ionic concentration of gingival crevicular fluid (GCF) rises with increases in the inflammation of the surrounding tissue. Because measurement of this increase might be useful for clinical assessment of periodontal status and because the sampling of this fluid is difficult in the typical clinical environment, attempts were made to measure the conductivity of GCF in vivo using a fabricated conductivity probe. Preliminary results suggest that statistically significant correlations may exist between certain clinical indices and GCF conductivity. A correlation could be shown when comparing the Gingival Index and the measured conductivity of GCF, but the correlation may be too low to be of biologic relevance, possibly due to the use of pooled samples. The use of an ion-specific probe and the study of site-specific periodontal lesions are suggested to develop more definitive data than this pilot study provided.