Scielo RSS <![CDATA[Revista médica de Chile]]> https://scielo.conicyt.cl/rss.php?pid=0034-988720060011&lang=pt vol. 134 num. 11 lang. pt <![CDATA[SciELO Logo]]> https://scielo.conicyt.cl/img/en/fbpelogp.gif https://scielo.conicyt.cl <![CDATA[Carta Médica de Chile]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100001&lng=pt&nrm=iso&tlng=pt <![CDATA[<b>Prognostic factors and outcome of community-acquired pneumonia in hospitalized adult patients</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100002&lng=pt&nrm=iso&tlng=pt Background: Severity assessment of community-acquired pneumonia (CAP) patients allows the clinician to decide the place of management and guide empirical antimicrobial treatment. Aim: To assess admission prognostic factors and outcome of CAP in immunocompetent adult patients hospitalized in 21 medical centers in Chile. Material and methods: Prospective evaluation of non immunocompromised adults with CAP admitted to 21 Chilean hospitals between July and August, 1999. All patients were assessed on admission and followed until discharge or death. Results: During the study period, 1,194 patients (aged 68±17 years, 573 males) were evaluated. Seventy two percent had an underlying disease (especially chronic cardiovascular, neurological, respiratory diseases and diabetes mellitus), and 90% were treated with ß-lactamic agents (especially a third generation cephalosporin or penicillin). Mean hospital length of stay was 11±9 days, 10% were admitted to Intermediate Care or Intensive Care Units (ICU), 6% were mechanically ventilated and in-hospital mortality was 15.7%. Admission prognostic factors associated with hospital mortality were: advanced age, male gender, presence of comorbidity (chronic cardiovascular, renal, neurological and hepatic disease), undernutrition, suspicion of aspiration, altered mental status, low blood pressure, tachypnea, absence of fever, high blood urea nitrogen, multilobar radiographic pulmonary infiltrates, high risk categories from Chilean Respiratory Diseases Society Consensus, admission to Intermediate Care Units or ICU, and mechanical ventilation. In the multivariate analysis, prognostic factors associated with high hospital mortality were: mental confusion, high blood urea nitrogen, multilobar pneumonia, presence of comorbidity and absence of fever on admission. Conclusions: These results validate in Chile, findings from foreign studies <![CDATA[<b>Frequency of TEL/AML1 and BCR/ABL fusion genes in children with acute lymphoblastic leukemia</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100003&lng=pt&nrm=iso&tlng=pt Background: t(12;21) (p12;q22) and t(9;22) (q34;q11) translocations have prognostic significance in acute lymphoblastic leukemia (ALL). The fusion genes TEL/AML1 y BCR/ABL, generated by these translocations, can be easily detected using molecular biology technique. Aim: To study the frequency of TEL/AML1 y BCR/ABL fusion genes in children with ALL. Material and methods: Fifity six children with ALL (age range 1 month- 14 years) were studied, thirty eight from our Temuco Hospital and 18 from the Metropolitan Region. TEL/AML1 y BCR/ABL fusion genes were detected in bone marrow samples using a reverse transcriptase nested polymerase chain reaction (RT-PCR). Results: TEL/AML 1 and BCR/ABL fusion gene transcripts were detected in 13 (23%) and 2 (4%) children, respectively. No differences in survival were observed between children with positive or negative transcripts for TEL/AML1 fusion gene. However, those positive for BCR/ABL fusion gene, had a significantly lower survival. Conclusions: The frequency of TEL/AML1 and BCR/ABL fusion gene transcripts in these children with ALL is similar to that described by other authors <![CDATA[<b>Split night polysomnography to titrate continuous positive airway pressure therapy in adult patients with obstructive sleep apnea</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100004&lng=pt&nrm=iso&tlng=pt Background: Nasal continuous positive airway pressure therapy (CPAP) in the treatment of choice for adult obstructive sleep apnea (OSA). The diagnosis is established with polysomnography, but this study is expensive and must be repeated in those patients that require CPAP, to titrate the pressure of the therapy. Split polysomnography during one night to establish the diagnosis and titrate the pressure has been proposed to reduce costs. Aim: To assess if CPAP pressure can be adequately titrated in patients with OSA using a split-night polysomnography. Material and methods: One hundred fifty six patients with OSA were studied with split night polysomnography. CPAP pressure titration was considered adequate when there were less than five apnea/hypopnea episodes per hour, the registry time was more than 30 min, REM sleep occurred in more than 15% of the time and measurements were made in supine position. Results: An adequate titration was achieved in 80% of patients. The variables associated with an adequate titration were a higher registry time during the titration period, a higher percentage of stage III/IV or REM sleep during such period and the comfort experienced by the patient during the study. On the other hand, patients with an inadequate titration had a longer basal registry period. Conclusions: An adequate CPAP pressure can be prescribed to 80% of patients subjected to a split-night polysomnography. The basal registry period should not be longer than three hours, to allow an adequate titration lapse <![CDATA[<b>One year follow up of successful coronary angioplasty in non selected patients</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100005&lng=pt&nrm=iso&tlng=pt Background:Re-stenosis after percutaneous Coronary Angioplasty (PTCA) is related to clinical and angiographic features. Aim: To describe the clinical and angiographic characteristic of our patients with coronary cardiopathy subjected to PTCA and the predictor factors for re-stenosis. Material and methods: We gathered the clinical and angiographic characteristics of all patients who underwent a successful PTCA of a native coronary artery. All patients had a clinical assessment one year after the procedure. Patients were classified in Group 1, if they did not have angina or coronary events after the angioplasty or Group 2, if they had angina or a coronary event after the procedure. Only Group 2 patients were subjected to a coronary angiogram. Results: We collected 383 PTCA procedures. Follow up information was obtained in 92.2%. Three hundred forty two patients (89.3%) were assessed one year the procedure. Nine patients (2.3%) died of a cardiovascular cause. Ninety patients (26.3%) were classified in Group 2. In 65 patients, angiographic re-stenosis was demonstrated (19%). Re-stenosis occurred in 36 and 13% of patients with an without Diabetes Mellitus, respectively (p <0.01). The other clinical predictor variables were a history of myocardial infarction (p =0.007), obesity (p =0.041) and hypercholesterolemia (p =0.050). None of the angiographic characteristics predicted restenosis. Stents were protective factors against restenosis (15.6% in stented lesions vs 25.4% in nonstented; p =0.01). Conclusions: Re-stenosis after angioplasty occured in 19% of our patients with angina or coronary events. The clinical variables associated with a higher risk of re-stenosis were diabetes (the main risk factor), previous myocardial infarction, obesity and hypercholesterolemia. Angiographic variables were not associated with re-stenosis. The use of stents decreases the incidence of re-stenosis in all groups) <![CDATA[<b>Early steroid withdrawal in pediatric renal transplantation</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100006&lng=pt&nrm=iso&tlng=pt Background: Cardiovascular risk, growth failure and the new immunosuppressive drugs, have encouraged steroid withdrawal or total avoidance with promising results in renal transplant (Tx) immunosuppression. Aim: To evaluate a new immunosuppressor protocol with early withdrawal of steroids in pediatric kidney transplant. Patients and methods: Prospective study in pediatric patients older than 1 year and low immunological risk. Group A (n =28): steroids in decreasing doses until day 7 post Tx, tacrolimus (FK) and micophenolate mofetil (MMF). Group B (n =28) control: steroids, cyclosporine and azathioprine or steroids, FK and MMF. In both groups the induction therapy included basiliximab. Anthropometric and biochemical variables (renal function, lipid profile, hematological, blood glucose and acid-base equilibrium), acute rejection and CMV infection, were evaluated. Mean values and variations for continuous variables were calculated at months 1, 6, 12 and 18. Results: Two children were withdrawn before month 2, one had an untreatable diarrhea and the second died due to Aspergillus septicemia. Mean values at months 1, 6, 12 and 18 for groups A and B: Creatinine clearence (ml/min): 85.4 vs 89; 79.9 vs 83; 89 vs 80; 79.8 vs 80.6 (p: ns); hematocrit (%): 28.8 vs 30.4; 31.7 vs 34.4; 34.4; 32.4 vs 34.8; 34.4 vs 35.5 (p: ns). Total cholesterol (mg/dl): 151 vs 206; 139 vs 174; 138 vs 186; 140 vs 180 (p <0.05). Mean delta height/age Z score at the first year: 0.5 vs 0.15; 0.7 vs 0.22; 0.97 vs 0.25 (p <0.05). Mean systolic blood pressure Z score: 0.9 vs 1.5; 0.5 vs 0.9; -0.3 vs 0.8; 0.1 vs 1.0 (p <0.05). The height/age Z score was significantly superior in patients without steroids. A normalization of growth patterns at month 18 was observed (< 0.05). Both groups presented a negative variation of creatinine clearance during the follow-up, but it was minor in the study group (p <0.05). Two acute rejections were found in each group, and no difference in CMV infections was observed. Conclusions: Early steroid withdrawal in pediatric renal transplant recipients was effective and safe and did not increase the risk of rejection <![CDATA[<b>Evaluation of a stroke unit at a university hospital in Chile</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100007&lng=pt&nrm=iso&tlng=pt Background: Stroke is the second specific cause of death in Chile, with a mortality rate of 48.6 per 100.000 inhabitans. It accounts for 6% of all hospitalizations among adults. Aim: To study the type of patients hospitalized at a Stroke Unit in a general hospital and the costs and benefits of such unit. Material and methods: A descriptive and retrospective study using a patient registry, developed in Access® that included separate sections for ischemic and hemorrhagic stroke. Established diagnostic criteria were used. The mean costs per patient and complications were also calculated. Results: During 2003, 425 stroke patients were admitted to our hospital and 105 (age range 30-89 years, 58% female) were hospitalized at the Stroke Unit. Eighty three percent had ischemic and 16% had hemorrhagic stroke. The most common etiologies were thrombosis in 41%, embolism in 36%, lacunar in 13%, arterial dissection in 5% and transient ischemic attack in 3%. Fifty eight percent of patients had partial anterior ischemic stroke (PACI), 73% had hypertension and 29.5% diabetes. Only 18% arrived to the Stroke Unit with less of 6 hours of evolution, 7% of patients were admitted within the 3 hours after the onset of symptoms and 18%, from 3 to 6 hours. The mean lenght of stay in the Stroke Unit was 6.6 days and at the hospital 9.9 days (p <0.01). The mean costs per patient at the Stroke Unit and at the hospital were US$ 5.550 and US$ 4.815, respectively (p =ns). Conclusions: The Stroke Unit decreases hospital stay days without raising costs importantly. The inclusion criteria for stroke patients admitted to the Unit were adequate and the stroke registry allowed a good assessment of the Unit operation <![CDATA[<b>Long term results for intermediate and high grade localized non Hodgkin lymphoma, treated with chemotherapy and radiotherapy</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100008&lng=pt&nrm=iso&tlng=pt Background: Treatment of intermediate and high grade non-Hodgkin lymphoma (NHL) includes chemotherapy with or without radiotherapy, depending on the clinical stage. The standard treatment for advanced NHL is 8 cycles of combined chemotherapy, cyclophosphamide, adriamicin, vincristine and prednisone (CHOP). Patients presenting with localized disease are treated with fewer chemotherapy cycles and involved field radiotherapy, with good results. Aim: To evaluate the treatment results including overall survival (OS) and event-free survival (EFS) in localized aggressive NHL patients treated at the Pontificia Universidad Católica de Chile, Clinical Hospital. Patients and Methods: Retrospective analysis of all patients with Ann Arbor stages I and II referred to the hematology and radiotherapy clinic between 1998 and 2003. OS and EFS analysis was made according to the Kaplan and Meier method. Log-rank and Cox methods were used for univariate and multivariate analyses, respectively. Chemotherapy and radiotherapy toxicities were scored according to World Health Organization (WHO) and Radiation Therapy Oncology Group (RTOG) scales, respectively. Results: 39 patients (20 men), aged between 20 to 85 years, were the source for this study. The average follow-up was 51 months (range 6-115). The 5 years OS and EFS were 72,4% and 63,3%, respectively. On univariate analysis, age over 60 was the only variable that affected negatively OS and EFS. Acute toxicity caused by chemotherapy and radiotherapy was uncommon. Conclusions: Age over 60 was the only independent variable associated with poor prognosis. The number of chemotherapy cycles and the drug combination did not influence the results. These results support the usefullness of a shortened chemotherapy regimen plus involved field radiotherapy <![CDATA[<b>Insulin sensitivity in children aged 6 to 16 years</b>: <b>Association with nutritional status and pubertal development</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100009&lng=pt&nrm=iso&tlng=pt Backgrounds: There is a high prevalence of obesity and hyperinsulinism among Chilean prepuberal children. Aim: To evaluate insulin sensitivity (IS) using fasting insulin, the Homeostasis Model Assessment (HOMA) and quantitative insulin-sensitivity check index (QUICKI) in Chilean children. Material and Methods: Body mass index (BMI), total body fat percentage (%TBF) using the sum of 4 skin folds, abdominal obesity determined through waist circumference (WC), pubertal maturation using five Tanner stages, fasting glucose (Glu) and insulin (Ins), were measured in 354 children aged 6 to 15 years (173 males). IS was evaluated using HOMA and QUICKI. Results: IS was strongly associated with %TBF and WC. Ins, HOMA and QUICKI were significantly correlated with BMI (r =0.412; 0.405 y -0.442, respectively), %TBF (r =0.370; 0.367 y -0.394, respectively), and WC (r =0.452; 0.446 y -0.481, respectively). Ins and HOMA increased and QUICKI decreased significantly (p <0.0001) with age. Children in a similar Tanner stage did not have differences in Ins, HOMA and QUICKI. No differences in Ins, HOMA and QUICKI were observed between children in Tanner stages 1 and 2. However, children in Tanner stages 1 and 2, had significantly lower Ins and HOMA and higher QUICKI than those in Tanner 3 to 5 stages. The highest Ins quartile for Tanner stages 1 and 2 was 10.0 µUI/dl; for Tanner stages 3 to five, the figure was 15.6 µUI/dl. Conclusions: These results confirm the relationship of IS with BMI, %TBF, WC and pubertal maturation. IS decreases significantly and fasting Ins levels increase approximately 50% with puberty. This fact must be considered for the diagnosis of hyperinsulinism and insulin resistance in children <![CDATA[<b>Comparison of three brands of intracardiac pacemarker leads</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100010&lng=pt&nrm=iso&tlng=pt Background: Electrode lead design and materials influence their performance, stability and manipulation characteristics. In our laboratory, we use straight intracardiac, active fixation, steroid eluting leads. These features are shared by three brands of pacemarker distributors. Aim: To compare the short term results of three brands of leads used in our laboratory in patients requiring the implant of a pacemarker of cardioverter. Material and methods: One hundred and four patients (mean age 70 years, 59 males) subjected to a pacemarker or cardioverter implant were studied and followed during the first three months post implant. In these patients, 49 Guidant Flextend® 4087 or 4088, 27 Saint Jude Tendril® 1488T and 10 Medtronic Capsurefix® 5076 leads were implanted in the right atrium and 60 Guidant Flextend® 4087 or 4088, 29 Saint Jude Tendril® 1488T and 19 Medtronic Capsurefix® 5076 leads were implanted in the right ventricle. Results: Implant parameters were adequate for all leads. A sub-acute rise in ventricular stimulation threshold was detected in one Flextrend® lead. Three atrial leads (two Flextend® and one Capsurefix®) and one Capsurefix® ventricular lead experienced an acute displacement. One patient with a Flextend® lead, had a cardiac tamponade caused by an atrial perforation. Conclusions: The three brands of leads tested can be successfully implanted with comparable parameters and without differences in the evolution of patients during the first three months <![CDATA[<b>McLeod syndrome</b>: <b>Multisystem</b><b> involvement associated with neuroacanthocytosis linked to X chromosome. </b><b>Report</b><b> of two related cases</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100011&lng=pt&nrm=iso&tlng=pt Neurological abnormalities associated with spiculated, "acanthocytic" red cells in blood have been described as neuroacanthocytosis. This is a heterogeneous group of conditions that can be clearly subdivided on the basis of recent genetic findings. The McLeod Syndrome, one of the core neuroacanthocytosis syndromes, is a rare X-linked disorder caused by mutations of the XK gene, an X-chromosomal gene of unknown function characterized by haemopoietic abnormalities and late-onset neurological and muscular defects. We report two Chilean brothers with the McLeod phenotype who showed important psychiatric features. The diagnosis may be elusive if the presence of acanthocytosis is not properly studied. We describe a method which allowed the diagnosis that unmasked acanthocytosis. Otherwise the condition could have remained undiagnosed as it had been for decades in this family. This syndrome must be considered when assessing a familial movement disorder, specially affecting males with relevant psychiatric features. A reliable test for acanthocytosis assessment is available <![CDATA[<b>Cholesterol embolism</b>: <b>Report of one case</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100012&lng=pt&nrm=iso&tlng=pt We report a 72 year-old male, that after a coronary angiogram presented pain, reduced distal skin temperature of both limbs, cyanosis of toes with preserved peripheral pulses and a rapidly progressive renal failure. Afterwards, the patient suffered a sudden bilateral amblyopia and hematochezia. Cholesterol embolism was confirmed with a skin biopsy and fundoscopy. A colonoscopy showed a possible ischemic colitis. After six months of follow up, the patient lost the distal phalanges of three toes, and renal failure stabilized, with a serum creatinine of 2.5 mg/dl. The diagnosis of cholesterol embolism is often missed, but it has a one year mortality of 80% and the presence of renal failure is the main prognostic indicator. Other prognostic indicators are the presence of high blood pressure, previous renal failure and peripheral artery disease <![CDATA[<b>Counseling</b>: <b>A comprehensive method to support the terminally ill</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100013&lng=pt&nrm=iso&tlng=pt During the last decades we have witnessed a progressive aging of the general population and a higher prevalence of chronic disease. This fact along with the appearance of infectious diseases like AIDS, anticipates that more patients will benefit from comprehensive palliative care. The objective of this article is to propose a simple, integral and effective method of emotional support to the patient, family and health team in palliative care (PC). PC receives little attention in medical schools, despite the great impact it has on standard health practice and quality of life of patients and their families. Our proposed method, counselling, has been empirically studied and proven to be an effective therapeutic tool in promoting behavioural changes that favour the outcome of many conditions. We believe that it facilitates PC practice, promoting direct conversation and identifying issues that can potentially cause suffering to the patients. It is based on the patient's autonomy, considers his multiple dimensions, uses and stimulates patient's own resources and coping strategies, to improve quality of life <![CDATA[<b>Marfan Syndrome</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100014&lng=pt&nrm=iso&tlng=pt Marfan Syndrome is an autosomic dominant genetic disorder of the elastic fibers of connective tissue. Although neonatal and infant forms of the disease exist, the classic Marfan Syndrome is the most frequent form of presentation in childhood and adolescence, whith a hereditary background in 70 to 85% of cases. Due to the natural evolution of the disease, there is a progressive involvement of different organs or systems such as skeletal, cardiovascular, dura, ocular, skin-integument and lungs. However, the suspicion must arise on skeletal clinical aspects which are first evident signs. The cardiovascular involvement appears later but is the major life threatening complication. When suspecting Marfan phenotype, it is mandatory to apply Ghent criteria based on family history and clinical findings to establish the diagnosis. If diagnosis is confirmed, the severity of organ involvement must be assessed, to take preventive and/or therapeutic measures, including the search of new cases among relatives. When patients do not fulfill the diagnostic criteria, they must have a yearly evaluation considering the natural progressive evolution of the disease. The aim of this review is to spread and unify criteria on this disease whose diagnosis is eminently clinical, that requires early integral and updated management by a multidisciplinary group, to obtain the best quality of life and survival <![CDATA[<b>The possible temporal lobe syndrome of Ivan IV the Terrible</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100015&lng=pt&nrm=iso&tlng=pt Ivan IV "The Terrible" was the first Tsar of all Russias and was crowned in 1547. He extended Russian territories and opened the route to Siberia in successful campaigns against Tartars. He increased his personal power to the point of generating an autocracy that isolated him progressively from the council of Boyars. He had a complex personality and his acts were impregnated by a profound religiousness, episodes of rage, mood changes and a sense of "personal fate". All these traits configure the controversial "temporal lobe personality". The possible association between these personality traits and the eventual epilepsy that Ivan IV could suffer, is discussed. This association is called "temporal lobe syndrome". Considering the mood changes, with severe irritability and episodes of control loss alternated with feelings of guilt, sadness and isolation, another possibility is that the Tsar had an affective bipolar disorder or, less probably, a personality disorder <![CDATA[<b>Randomized trials stopped early for benefit</b>: <b>is it good or bad?</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100016&lng=pt&nrm=iso&tlng=pt Ivan IV "The Terrible" was the first Tsar of all Russias and was crowned in 1547. He extended Russian territories and opened the route to Siberia in successful campaigns against Tartars. He increased his personal power to the point of generating an autocracy that isolated him progressively from the council of Boyars. He had a complex personality and his acts were impregnated by a profound religiousness, episodes of rage, mood changes and a sense of "personal fate". All these traits configure the controversial "temporal lobe personality". The possible association between these personality traits and the eventual epilepsy that Ivan IV could suffer, is discussed. This association is called "temporal lobe syndrome". Considering the mood changes, with severe irritability and episodes of control loss alternated with feelings of guilt, sadness and isolation, another possibility is that the Tsar had an affective bipolar disorder or, less probably, a personality disorder <![CDATA[<b>Critically appraised article</b>: <b>Levofloxacin</b><b> to Prevent Bacterial Infection in Patients with Cancer and Neutropenia</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100017&lng=pt&nrm=iso&tlng=pt Background: The prophylactic use of fluoroquinolones in patients with cancer and neutropenia is controversial and is not a recommended intervention. Methods: We randomly assigned 760 consecutive adult patients with cancer in whom chemotherapy-induced neutropenia (<1000 neutrophils per cubic millimeter) was expected to occur for more than seven days to receive either oral levofloxacin (500 mg daily) or placebo from the start of chemotherapy until the resolution of neutropenia. Patients were stratified according to their underlying disease (acute leukemia vs solid tumor or lymphoma). Results: An intention-to-treat analysis showed that fever was present for the duration of neutropenia in 65 percent of patients who received levofloxacin prophylaxis, as compared with 85 percent of those receiving placebo (243 of 375 vs 308 of 363; relative risk, 0.76; absolute difference in risk, -20 percent; 95 percent confidence interval, -26 to -14 percent; P=0.001). The levofloxacin group had a lower rate of microbiologically documented infections (absolute difference in risk, -17 percent; 95 percent confidence interval, -24 to -10 percent; P <0.001), bacteremias (difference in risk, -16 percent; 95 percent confidence interval, -22 to -9 percent; P <0.001), and single-agent gram-negative bacteremias (difference in risk, -7 percent; 95 percent confidence interval, -10 to -2 percent; P <0.01) than did the placebo group. Mortality and tolerability were similar in the two groups. The effects of prophylaxis were also similar between patients with acute leukemia and those with solid tumors or lymphoma. Conclusions: Prophylactic treatment with levofloxacin is an effective and well-tolerated way of preventing febrile episodes and other relevant infection-related outcomes in patients with cancer and profound and protracted neutropenia. The long-term effect of this intervention on microbial resistance in the community is not known <![CDATA[<b>On medical professionalism</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100018&lng=pt&nrm=iso&tlng=pt Background: The prophylactic use of fluoroquinolones in patients with cancer and neutropenia is controversial and is not a recommended intervention. Methods: We randomly assigned 760 consecutive adult patients with cancer in whom chemotherapy-induced neutropenia (<1000 neutrophils per cubic millimeter) was expected to occur for more than seven days to receive either oral levofloxacin (500 mg daily) or placebo from the start of chemotherapy until the resolution of neutropenia. Patients were stratified according to their underlying disease (acute leukemia vs solid tumor or lymphoma). Results: An intention-to-treat analysis showed that fever was present for the duration of neutropenia in 65 percent of patients who received levofloxacin prophylaxis, as compared with 85 percent of those receiving placebo (243 of 375 vs 308 of 363; relative risk, 0.76; absolute difference in risk, -20 percent; 95 percent confidence interval, -26 to -14 percent; P=0.001). The levofloxacin group had a lower rate of microbiologically documented infections (absolute difference in risk, -17 percent; 95 percent confidence interval, -24 to -10 percent; P <0.001), bacteremias (difference in risk, -16 percent; 95 percent confidence interval, -22 to -9 percent; P <0.001), and single-agent gram-negative bacteremias (difference in risk, -7 percent; 95 percent confidence interval, -10 to -2 percent; P <0.01) than did the placebo group. Mortality and tolerability were similar in the two groups. The effects of prophylaxis were also similar between patients with acute leukemia and those with solid tumors or lymphoma. Conclusions: Prophylactic treatment with levofloxacin is an effective and well-tolerated way of preventing febrile episodes and other relevant infection-related outcomes in patients with cancer and profound and protracted neutropenia. The long-term effect of this intervention on microbial resistance in the community is not known <![CDATA[<b>Gastrointestinal stromal tumours (GIST)</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100019&lng=pt&nrm=iso&tlng=pt Background: The prophylactic use of fluoroquinolones in patients with cancer and neutropenia is controversial and is not a recommended intervention. Methods: We randomly assigned 760 consecutive adult patients with cancer in whom chemotherapy-induced neutropenia (<1000 neutrophils per cubic millimeter) was expected to occur for more than seven days to receive either oral levofloxacin (500 mg daily) or placebo from the start of chemotherapy until the resolution of neutropenia. Patients were stratified according to their underlying disease (acute leukemia vs solid tumor or lymphoma). Results: An intention-to-treat analysis showed that fever was present for the duration of neutropenia in 65 percent of patients who received levofloxacin prophylaxis, as compared with 85 percent of those receiving placebo (243 of 375 vs 308 of 363; relative risk, 0.76; absolute difference in risk, -20 percent; 95 percent confidence interval, -26 to -14 percent; P=0.001). The levofloxacin group had a lower rate of microbiologically documented infections (absolute difference in risk, -17 percent; 95 percent confidence interval, -24 to -10 percent; P <0.001), bacteremias (difference in risk, -16 percent; 95 percent confidence interval, -22 to -9 percent; P <0.001), and single-agent gram-negative bacteremias (difference in risk, -7 percent; 95 percent confidence interval, -10 to -2 percent; P <0.01) than did the placebo group. Mortality and tolerability were similar in the two groups. The effects of prophylaxis were also similar between patients with acute leukemia and those with solid tumors or lymphoma. Conclusions: Prophylactic treatment with levofloxacin is an effective and well-tolerated way of preventing febrile episodes and other relevant infection-related outcomes in patients with cancer and profound and protracted neutropenia. The long-term effect of this intervention on microbial resistance in the community is not known <![CDATA[<b>Crónica</b>]]> https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100020&lng=pt&nrm=iso&tlng=pt Background: The prophylactic use of fluoroquinolones in patients with cancer and neutropenia is controversial and is not a recommended intervention. Methods: We randomly assigned 760 consecutive adult patients with cancer in whom chemotherapy-induced neutropenia (<1000 neutrophils per cubic millimeter) was expected to occur for more than seven days to receive either oral levofloxacin (500 mg daily) or placebo from the start of chemotherapy until the resolution of neutropenia. Patients were stratified according to their underlying disease (acute leukemia vs solid tumor or lymphoma). Results: An intention-to-treat analysis showed that fever was present for the duration of neutropenia in 65 percent of patients who received levofloxacin prophylaxis, as compared with 85 percent of those receiving placebo (243 of 375 vs 308 of 363; relative risk, 0.76; absolute difference in risk, -20 percent; 95 percent confidence interval, -26 to -14 percent; P=0.001). The levofloxacin group had a lower rate of microbiologically documented infections (absolute difference in risk, -17 percent; 95 percent confidence interval, -24 to -10 percent; P <0.001), bacteremias (difference in risk, -16 percent; 95 percent confidence interval, -22 to -9 percent; P <0.001), and single-agent gram-negative bacteremias (difference in risk, -7 percent; 95 percent confidence interval, -10 to -2 percent; P <0.01) than did the placebo group. Mortality and tolerability were similar in the two groups. The effects of prophylaxis were also similar between patients with acute leukemia and those with solid tumors or lymphoma. Conclusions: Prophylactic treatment with levofloxacin is an effective and well-tolerated way of preventing febrile episodes and other relevant infection-related outcomes in patients with cancer and profound and protracted neutropenia. The long-term effect of this intervention on microbial resistance in the community is not known https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872006001100021&lng=pt&nrm=iso&tlng=pt