Scielo RSS <![CDATA[Revista médica de Chile]]> https://scielo.conicyt.cl/rss.php?pid=0034-988720040009&lang= vol. 132 num. 9 lang. <![CDATA[SciELO Logo]]> https://scielo.conicyt.cl/img/en/fbpelogp.gif https://scielo.conicyt.cl <![CDATA[<B>Prediction rules in community acquired pneumonia </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900001&lng=&nrm=iso&tlng= The determination of site of care is an essential decision in the management of patients with community-acquired pneumonia (CAP). Patients with mild to moderate CAP may be safely treated at home. Instead, those patients with severe pneumonia must be hospitalized to assure an effective treatment. Severity of CAP is associated with mortality that depends both on the patient's frailty and the intensity of lung inflammation. Because there is no single predictor factor to assess prognosis, diverse prediction rules have been developed to establish severity of CAP and guide the decision of site of care. In our country a new prediction rule, derived from hospitalized patients that incorporate simple clinical variables has been developed. However, this rule requires to be validated in the ambulatory setting before its wide spread use is suggested. Prediction rules are objective and relatively accurate models to assess prognosis that may aid clinicians to evaluate patient's risks and to improve hospitalization decisions. Nevertheless, although the prediction rules may guide the initial management of patients with CAP, they are not intended to replace the clinical judgment, which remains as the «art of medicine» (Rev Méd Chile 2004; 132: 1027-30) <![CDATA[<B>Prognostic value of hyperuricemia in chronic heart failure</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900002&lng=&nrm=iso&tlng= Background: Hyperuricemia has been proposed as a risk marker in chronic heart failure, but its value as an independent prognostic is not well established. Aim: To determine the prognostic value of hyperuricemia, in patients with chronic stable heart failure. Patients and methods: Forty six male patients with chronic heart failure, aged 62±13 years, were studied. Their ejection fraction was less than 40% and their serum creatinine was less than 2 mg/dl. Serum uric acid and catecholamines, maximal oxygen consumption (VO2 max) and left ventricular ejection fraction were measured. Mortality and the need for cardiac transplant were recorded as endpoints during a mean follow up of 39±18 months. The relationship between basal measures and the occurrence of events was analyzed using univariate and multivariate methods. Results: Basal VO2 max and left ventricular ejection fraction were 16±4.6 ml/kg/min and 22±7% respectively. Eighteen patients died and three required transplantation during the follow up. Patients reaching these endpoints had a lower VO2 max and left ventricular ejection fraction and higher uric acid levels. Multivariate analysis accepted left ventricular ejection fraction (relative risk 0.89, 95% CI 0.82-0.97) and serum uric acid (relative risk 1.335 95% CI 1.02-1.74) as significant predictors of events. The relative risk for cardiac transplantation was 7.07 times higher among those with a serum uric acid over 7 mg/dl. Conclusions: A high serum uric acid is an independent predictor of bad prognosis in patients with stable chronic heart failure (Rev Méd Chile 2004; 132: 1031-6 <![CDATA[<B>Development of an instrument to assess the severity of community acquired pneumonia among hospitalized patients</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900003&lng=&nrm=iso&tlng= Background: Community acquired pneumonia (CAP) severity assessment is crucial. Aim: To develop a practical clinical severity assessment model for stratifying immunocompetent adult patients hospitalized with CAP into different management groups. Patients and methods: During a 24 months period, 455 adult patients (250 male, mean age 69±19 years old) were evaluated. All the relevant clinical information recorded and they were followed during hospital stay until discharge or death. Mortality until 30 days after admission was determined. Results: The mean hospital length of stay was 9.9±9.4 days and 76% had an underlying disease. In hospital mortality was 7.6% and 10.1% at 30 days follow up. Admission prognostic factors associated with high mortality at 30 days follow up were: advanced age, presence of comorbidity, suspicion of aspiration, duration of symptoms ­2 days, altered mental status, absence of cough, fever and chills; low blood pressure, tachypnea, hypoxemia and multilobar radiographic pulmonary infiltrates. A clinical prognostic index derived from a logistic regression analysis including five independent variables associated with mortality (confusion, comorbidity, low systolic blood pressure, temperature <37.5°C and respiratory rate >20/min), enabled patients to be stratified according to increasing risk of mortality: class 1: 0.9%, class 2: 4.9%, class 3: 14.2%, and class 4: 35.6%. Conclusion: A simple clinical severity assessment tool based on confusion, comorbidity, blood pressure, temperature and respiratory rate could be used to stratify patients with CAP into different risk class categories and management groups (Rev Méd Chile 2004; 132: 1037-46) <![CDATA[<B>Presence of DRD4/7R and DAT1/10R allele in Chilean family members with attention deficit hyperactivity disorder</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900004&lng=&nrm=iso&tlng= Background: Genes for dopamine receptor DRD4 and dopamine transporter DAT1 have been implicated in attention deficit with hyperactivity disorder (ADHD). However, the findings are not conclusive. More studies in populations with different genetic brackgrounds may contribute to solve the discrepancies observed. Aim: To test the hypothesis that affected members of Chilean families exhibit higher frequencies of the DRD4/7R and DAT1/10R alleles then their healthy sibs. Material and Methods: The parents of 51 children belonging to families of the Metropolitan Region of Chile, were approached to obtain clinical histories and blood samples, after the signature of a written informed consent. ADHD was diagnosed according to DSM-IV criteria, and intellectual coefficient was tested using the WISC-R test. Genomic DNA was extracted from lymphocytes and amplified by PCR. Results: The 7R allele was identified in 13 out of 26 subjects diagnosed as ADHD and in 6 of 25 healthy sibs (p <0.05). Parents with a history of ADHD, were compared with their healthy counterparts, exhibiting an identical tendency, that did not reach statistical significance. No significant differences in the frequencies of DAT1/10R alleles, were observed between cases and controls or their parents. Conclusions: Our results showed that ADHD in Chilean families is associated with the presence of DRD4/7R allele (Rev Méd Chile 2004; 132: 1047-52) <![CDATA[<B>Free urinary cortisol is elevated in patients with low-renin essential hypertension </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900005&lng=&nrm=iso&tlng= Background: Glucocorticoids play a key role in blood pressure (BP) control and are associated with hypertension in patients with Cushing's syndrome. A number of reports indicate that cortisol (F) may be involved in etiology of essential hypertension (EH). F can bind to the mineralocorticoid receptor, triggering both sodium and water reabsorption in kidney, increase BP and cause renin suppression. Aim: To evaluate urinary free cortisol (UFF) excretion as a potential intermediate phenotype of essential hypertension and correlate F level with plasma renin activity (PRA) and serum aldosterone (SA). Patients and Methods: We recruited 132 EH patients and 16 normotensive healthy controls. Blood samples and 24 hours urine were collected for PRA, SA and UFF analysis. Differences in UFF excretion between sexes were normalized by urinary creatinine (Creat) excretion. The upper limit of UFF/Creat was determined in normotensives considering the mean value plus 2 standard deviations. According to this value, subjects were classified as having high or normal UFF. Results: In EH patients and in normotensives, the UFF/Creat was 36.9±17.0 µg/gr and 30.9±8.8 µg/gr, respectively. The upper limit was set at 48.5 µg/gr. A high UFF/Creat was found in 20/132 EH (15%) patients and 0/16 normotensive subjects. EH patients with high UFF showed lower PRA levels than patients with normal cortisol levels (0.78±0.47 vs. 1.13±0.66 ng/ml*h, respectively, p=0.027) and lower SA values (4.52±1.65 vs 6.34±3.37 ng/dl, respectively, p=0.018). There was a negative correlation between UFF and PRA (r=-0.176, p=0.044) and between UFF and SA (r=-0.183, p=0.036). Conclusions: We have identified a subgroup of EH patients with increased UFF excretion. Patients with the highest UFF showed lower renin and aldosterone levels. These data suggest a potential influence of cortisol in the genesis of hypertension (Rev Méd Chile 2004; 132: 1053-9) <![CDATA[<B>Polymorphisms of the multiple drug resistance gene (MDR1) in Mapuche, Mestizo and Maori populations in Chile </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900006&lng=&nrm=iso&tlng= Background: There are significant differences in drug responses among different ethnic groups. The multidrug transporter P-gp, encoded by the MDR1 gene, plays a key role in determining drug bioavailability, and an association between a polymorphism in exon 26 (C3435T) and lower P-gp expression has been found. The co-segregation of this polymorphism with the polymorphism in exon 12 (C1236T) and in exon 21 (G2677T/A) determines several MDR1 haplotypes in humans. Aim: To characterize the polymorphisms of exons 26, 21 and 12 of the MDR1 gene in different Chilean populations. Material and methods: Using a polymerase chain reaction and restriction fragment length polymorphism technique, we studied the allelic frequencies and the distribution of MDR1 haplotypes in 3 Chilean populations: Mestizo (n=104), Mapuche (n=96, living in the National Reservation of the Huapi Island, Ranco Lake) and Maori (n=52, living in Eastern Island). Results: The frequency of the normal MDR1*1 haplotype, without mutations, was lower in Mapuches than in Mestizos or Maoris (p <0.005) but similar to that reported in Asian population (p=0.739), probably due to the Asian origin of the Amerindian populations. In addition, the MDR1*l haplotype frequency in Mestizos was similar to the frequency reported in Caucasians (p=0.49), in agreement with the origin of our population, with a strong influence of Caucasian genes from the Spanish conquerors. The MDR1*2 haplotype distribution, with the three polymorphisms and probably lower multidrug transporter expression, was similar in the three Chilean populations studied (p >0.05), but lower than the frequencies reported in Caucasians or Asians (p <0.05). Conclusions: We found significant differences in the frequencies of genetic polymorphisms of the MDR1 gene in Chilean populations, related to the ethnic origins of our ancestors (Rev Méd Chile 2004; 132: 1061-8 <![CDATA[<B>Promoter methylation profile in breast cancer </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900007&lng=&nrm=iso&tlng= Background: Genomic DNA methylation, mutations and allelic deletions explain the inactivation of genes involved in cell proliferation and cell cycle control mechanisms. Aim: To analyze the methylation pattern of important genes related to different carcinogenic mechanisms in patients with breast cancer and the relationship with its biological behavior. Material and methods: Seventy fresh-frozen breast cancer samples were selected. The methylation specific PCR (MSP) test was used to analyze promoter methylation status for genes CDKN2A (p16), hMLH1, APC, CDH1 (Cadherin E) and FHIT. Results: We found methylation in at least one of the genes studied in 88% of cases and in 3 or more genes in 40.5% of cases. The frequencies of promoter hypermethylation of CDKN2A, hMLH1, APC, CDH1 and FHIT were 41.4%, 11.4%, 52.9%, 70% y 42.9%, respectively. We found a relationship between CDKN2A methylation and better survival (p=0.002). CDH1 methylation and poor histological differentiation (p=0.007), hMLH1 methylation and non-Mapuche ethnicity (p=0.03), APC methylation and larger tumor size (p <0.05), FHIT methylation and lack of estrogen receptor IHC expression (p <0.05). Conclusions: The high frequency of promoter methylation in patients with breast cancer confirms its role in breast carcinogenesis. The finding of alterations in the methylation pattern of genes studied and its association with prognostic factors is a helpful tool in the search of new criteria for clinical and therapeutic decision making (Rev Méd Chile 2004; 132: 1069-77) <![CDATA[<B>Laboratory diagnosis of patients with exanthematic or febrile syndromes occurring in the Zulia state, Venezuela, during 1998 </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900008&lng=&nrm=iso&tlng= Background: Exanthematic diseases are a group of syndromes mainly caused by acute viral infections. Aim: To obtain information about the viruses that cause exanthematic diseases in our region. Patients and methods: During 1998, 267 serum samples from patients with an acute rash or patients presenting a febrile syndrome accompanied by enlarged lymph nodes, headache and other symptoms, were collected. Specific antibody of the IgM class (anti-IgM) against Rubella, Measles, Dengue types 1-4 and Cytomegalovirus (CMV) were measured by immunoenzymatic assay (EIA). Epstein-Barr virus (EBV) antibodies were measured by immunofluorescence. Results: An etiologic agent was detected in 208 cases (77.9%). Cases due to Dengue (40,6%) and Rubella (21%) viruses predominated, but the frequency of other agents was also high in specific age groups. The agreement between the clinical suspicion and the laboratory findings varied broadly, from a 100% for suspected Dengue to just a 14,8% for cases of suspected CMV infection. Conclusions: Dengue was the most common viral exanthematic disease in the Zulia State during 1998 (Rev Méd Chile 2004; 132: 1078-84 <![CDATA[<B>Non-urgent patients in an Emergency Medical Service</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900009&lng=&nrm=iso&tlng= Background: Emergency Medical Services (ES) are medical-surgical facilities where extremely ill patients, victims of accidents, intoxications and other urgent clinical situations should be rapidly and efficiently attended. However, a worldwide experience is that a large proportion of patients who require attention in an ES do not qualify as emergencies and they obstruct the possibilities of other patients that should be attended immediately. Aim: To evaluate the medical records in our ES and to assess whether patients understand what is a true emergency and which is the role of an ES. Methods: Patients attended in the ES of Haydarpasa Military Teaching Hospital in 2001-2002 were classified according to their diagnosis. A random sample of patients and relatives were surveyed about why they required medical attention in the ES. Results: 77,134 patients (39,327 female, 51%) were attended. The most common illness diagnosed was upper respiratory tract infection (18,423 patients, 23.9%). The true emergency condition rate in patients presenting to our ES was lower (44%) than the non-emergency condition rate. Conclusions: Improvements in public education are needed to solve this problem. Also, Primary Care facilities should be improved in order to reduce the demand for medical attention in ES by non-urgent patients (Rev Méd Chile 2004; 132: 1085-9)<hr/>Antecedentes: Los Servicios de Urgencia son unidades médico-quirúrgicas donde deberían atenderse rápida y eficientemente pacientes graves, víctimas de accidentes, intoxicaciones y otras situaciones clínicas urgentes. Sin embargo, es una experiencia mundial que una proporción importante de los consultantes en Servicios de Urgencia no califican como emergencias, pero dificultan las posibilidades de atención para otros pacientes que deberían ser atendidos de inmediato. Propósito: Evaluar las fichas clínicas en nuestro Servicio de Urgencia y averiguar si los pacientes comprenden cuál es una verdadera emergencia y cuál es la función de un Servicio de Urgencia. Métodos: Los pacientes atendidos en el Servicio de Urgencia del Hospital Clínico Militar Haydarpasa (Estambul, Turquía) en 2001-2002 fueron calificados retrospectivamente según sus diagnósticos. Una muestra al azar de pacientes y sus parientes acompañantes fueron encuestados sobre sus razones para solicitar atención en el Servicio de Urgencia. Resultados: Se atendieron 77.134 pacientes (39.327 del sexo femenino, 51%). El diagnóstico más frecuente correspondió a infección del tracto respiratorio (18.423 pacientes, 23,9%). La proporción de pacientes que calificaron como reales urgencias (44%) fue menor que los calificados como no-urgentes. Conclusiones: Para disminuir la demanda de atención en Servicios de Urgencia por pacientes no-urgentes se requiere mejorar la educación del público y aumentar la disponibilidad de policlínicas de atención primaria, ampliando su horario de atención <![CDATA[<B>Hepatic veno-occlusive disease, idiopathic ulcerative colitis and portal thrombosis</B>: <B>Report of one case</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900010&lng=&nrm=iso&tlng= We report a previously healthy 29 years old man, presenting with a sudden episode of abdominal pain, mild jaundice, hepatomegaly and ascites. Magnetic resonance imaging study and liver biopsy were compatible with veno-occlusive disease. Incidentally, an ulcerative colitis and portal vein thrombosis were diagnosed. Anticoagulant treatment was started, with good clinical and radiological response. Veno-occlusive disease of the liver must be suspected in cases of liver failure and ascites associated to procoagulant conditions (Rev Méd Chile 2004; 132: 1091-5) <![CDATA[<B>Familial generalized thyroid hormone resistance. Report of one case </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900011&lng=&nrm=iso&tlng= hyroid hormone resistance is a rare autosomal dominant disease associated, in more than 90% of cases, to mutations in the beta thyroid hormone receptor. We report a 23 years old male that consulted for a psychiatric condition. Clinically, the patient was euthyroid in spite of high total and free T4 and T3 concentrations, while TSH remained normal. Also, TSH showed a five fold increase under TRH stimulation. The mother and one of his brothers had the same pattern of abnormal serum thyroid hormones. We discuss the diagnostic considerations and the protocol to study this rare pathology (Rev Méd Chile 2004; 132: 1096-9) <![CDATA[<B>Work absenteeism in Chile according to the type of work place </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900012&lng=&nrm=iso&tlng= Background: The issue of medically justified work absenteeism has a great relevance in Chile at the present moment. Aim: To analyze sick leaves among people working in hospitals, mines, automotive industry and universities. Material and methods: Analysis of 14 thesis and research papers about absenteeism in Chile. The incapacity rate (number of days with sick leave per worker per yea), the frequency rate (number of sick leaves per year per worker) and the severity rate (mean duration of sick leaves) were calculated. The diseases causing the highest rates of absenteeism were also recorded. Results: The mean age of the studied populations was 36 years old and the most common diseases causing absenteeism were respiratory, rheumatologic and trauma. Hospital workers had the highest incapacity rate with 14.3 days of sick leave per worker per year, followed by mining industry with 12 days, automotive industry with 7.1 days and universities with 6 days. Conclusions: In Chile, respiratory diseases are the main cause of sick leaves and hospital workers have the highest incapacity rate (Rev Méd Chile 2004; 132: 1100-8) <![CDATA[<B>Intercultural health care policy from the perspective of health care providers and mapuche clients </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900013&lng=&nrm=iso&tlng= Background: Intercultural health is becoming an emergent topic in the design of health care programs for Mapuche people of Chile. This process faces important challenges such as the scarce theoretical support about the meaning of intercultural health and their practical consequences for providers and clients. Aim: To explore the perception in providers and Mapuche clients about intercultural health. Material and methods: A survey performed in 11 counties with the highest concentration of Mapuche people, of the IX region of Chile. The perception about the development of a new health policy specially designed for Mapuche patients was surveyed in 399 Mapuche patients and 64 providers of primary health care centers. Results: Mapuche clients considered, as the main regional challenges, the indifference and discrimination of health care teams towards Mapuche patients, aggravated by the indifference of authorities. Providers considered that the main problem was a lack of knowledge about Mapuche culture and skills to deal with this ethnic group. Patients and providers agreed on the need to use Mapuche dialect in health care attentions, to coordinate actions with traditional healers and to accept ethnical therapeutic practices. Conclusions: There is scarce agreement between providers and Mapuche clients about the need for an special intercultural health policy, its contents, and the regional conditions for its implementation and development (Rev Méd Chile 2004; 132: 1109-14) <![CDATA[<B>Advances in cellular immunotherapy for malignant melanoma</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900014&lng=&nrm=iso&tlng= An alternative strategy for cancer treatment is the manipulation of the immune system, denominated cancer immunotherapy. The immunotherapeutical use of cells of the immune system, like dendritic cells (DC), is being explored in different clinical protocols. Recently, we finalized a clinical phase I protocol, for the treatment of malignant melanoma, using DCs loaded with tumor lysates. Our results indicate that the subcutaneous application of DCs do not produce adverse effects. We also observed an increase of tumor spe-cific T lymphocytes precursors in the blood, associated to hypersensitivity reactions (DTH) in 60% of the treated patients. In most cases, an stability in the disease was observed, although without a significant association between vaccination and survival. Additionally, therapies based on Interleukin-2 (IL-2) have been used with relative success in the treatment of some kind of tumors since 1985. However, problems associated to the toxicity of IL-2 still restrict its massive use. Our direct experience with the use of IL-2, indicates that low doses and its subcutaneous application, maintains the beneficial effects for patients, eliminating the adverse effects. Based on the accumulated evidence during last the five years, we decided to implement an optimized clinical protocol, which alternatively combines dendritic cells vaccines with the use of low doses of IL-2 for the reinforcement of the immunological system (Rev Méd Chile 2004; 132: 1115-26) <![CDATA[<B>The influence of phychological features and learning styles on the academic performance of medical students</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900015&lng=&nrm=iso&tlng= Background: The degree of difficulty we experience while learning different concepts and skills depends, among other things, on our psychological features and learning style. This may be particularly true for medical students, whose formation involves the acquisition of multiple cognitive, affective and psychomotor skills. Aim: To assess whether the psychological features and learning styles of medical students are associated with their academic performance. Subjects and Methods: The psychological preferences and learning styles of 66 students of the 2001-graduating cohort were determined with the Myers Briggs Type Inventory (MBTI) and the Kolb Learning Style Inventory (LSI), respectively. The academic performance was assessed by the Calificación Médica Nacional (CMN), Chile and by the marks obtained during the Basic (1st to 3th), Preclinical (4th y 5th) and Clinical (6th y 7th) years of undergraduate training. Results: The psychological features, together with the sex of students were found to be associated with the performance in the Preclinical and Clinical years, and to the CMN. In men, the interest and ability to communicate with people and the concern for harmony, and in women the tendency to function in a systematic and orderly way are the features associated to high academic performance. No associations were found between learning styles and academic performance. Conclusions: The finding that the psychological preferences of medical students are relevant to their academic performance opens a new perspective to analyze the medical education and to design programs aimed at improving learning (Rev Méd Chile 2004; 132: 1127-36) <![CDATA[<B>Blinding for clinical trials. Does it matter</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900016&lng=&nrm=iso&tlng= Background: The degree of difficulty we experience while learning different concepts and skills depends, among other things, on our psychological features and learning style. This may be particularly true for medical students, whose formation involves the acquisition of multiple cognitive, affective and psychomotor skills. Aim: To assess whether the psychological features and learning styles of medical students are associated with their academic performance. Subjects and Methods: The psychological preferences and learning styles of 66 students of the 2001-graduating cohort were determined with the Myers Briggs Type Inventory (MBTI) and the Kolb Learning Style Inventory (LSI), respectively. The academic performance was assessed by the Calificación Médica Nacional (CMN), Chile and by the marks obtained during the Basic (1st to 3th), Preclinical (4th y 5th) and Clinical (6th y 7th) years of undergraduate training. Results: The psychological features, together with the sex of students were found to be associated with the performance in the Preclinical and Clinical years, and to the CMN. In men, the interest and ability to communicate with people and the concern for harmony, and in women the tendency to function in a systematic and orderly way are the features associated to high academic performance. No associations were found between learning styles and academic performance. Conclusions: The finding that the psychological preferences of medical students are relevant to their academic performance opens a new perspective to analyze the medical education and to design programs aimed at improving learning (Rev Méd Chile 2004; 132: 1127-36) <![CDATA[<B>Análisis crítico de un artículo</B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900017&lng=&nrm=iso&tlng= Background: Few reports have addressed the value of unfractionated heparin (UFH) or low-molecular-weight heparin in treating the full spectrum of patients with venous thromboembolism (VTE), including recurrent VTE and pulmonary embolism. Methods: In an open, multicenter clinical trial, 720 consecutive patients with acute symptomatic VTE, including 119 noncritically ill patients (16.5%) with pulmonary embolism and 102 (14.2%) with recurrent VTE, were randomly assigned to treatment with subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm (preceded by an intravenous loading dose), or fixed-dose (adjusted only to body weight) subcutaneous nadroparin calcium. Oral anticoagulant therapy was started concomitantly and continued for at least 3 months. We recorded the incidence of major bleeding during the initial heparin treatment and that of recurrent VTE and death during 3 months of follow-up. Results: Fifteen (4.2%) of the 360 patients assigned to UFH had recurrent thromboembolic events, as compared with 14 (3.9%) of the 360 patients assigned to nadroparin (absolute difference between rates, 0.3%; 95% confidence interval, -2.5% to 3.1%). Four patients assigned to UFH (1.1%) and 3 patients assigned to nadroparin (0.8%) had episodes of major bleeding (absolute difference between rates, 0.3%; 95% confidence interval, -1.2% to 1.7%). Overall mortality was 3.3% in each group. Conclusions: Subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm is as effective and safe as fixed-dose nadroparin for the initial treatment of patients with VTE, including those with pulmonary embolism and recurrent VTE <![CDATA[<B>Training in Hematology, in Chile </B>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900018&lng=&nrm=iso&tlng= Background: Few reports have addressed the value of unfractionated heparin (UFH) or low-molecular-weight heparin in treating the full spectrum of patients with venous thromboembolism (VTE), including recurrent VTE and pulmonary embolism. Methods: In an open, multicenter clinical trial, 720 consecutive patients with acute symptomatic VTE, including 119 noncritically ill patients (16.5%) with pulmonary embolism and 102 (14.2%) with recurrent VTE, were randomly assigned to treatment with subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm (preceded by an intravenous loading dose), or fixed-dose (adjusted only to body weight) subcutaneous nadroparin calcium. Oral anticoagulant therapy was started concomitantly and continued for at least 3 months. We recorded the incidence of major bleeding during the initial heparin treatment and that of recurrent VTE and death during 3 months of follow-up. Results: Fifteen (4.2%) of the 360 patients assigned to UFH had recurrent thromboembolic events, as compared with 14 (3.9%) of the 360 patients assigned to nadroparin (absolute difference between rates, 0.3%; 95% confidence interval, -2.5% to 3.1%). Four patients assigned to UFH (1.1%) and 3 patients assigned to nadroparin (0.8%) had episodes of major bleeding (absolute difference between rates, 0.3%; 95% confidence interval, -1.2% to 1.7%). Overall mortality was 3.3% in each group. Conclusions: Subcutaneous UFH with dose adjusted by activated partial thromboplastin time by means of a weight-based algorithm is as effective and safe as fixed-dose nadroparin for the initial treatment of patients with VTE, including those with pulmonary embolism and recurrent VTE https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872004000900019&lng=&nrm=iso&tlng=