Oxidative status of the myocardium in response to different intensities of physical training.

The intensity of exercise determines the metabolic pathway and the energetic substrate that is spent. Our study sought to identify the effects of different intensities of swimming on myocardial oxidative status and the blood lipid profile. Eighty Wistar rats (male and female) submitted to different intensities of a swimming regimen (low, LS; moderate, MS; or high, HS) for 16 weeks. Samples of blood and myocardium from the left ventricle were collected to determine lipid profiles and oxidative status. Reactive oxygen species (ROS) and antioxidant capacity against peroxyl radicals (ACAP), lipid profiles and lipid peroxidation was analyzed. ROS levels and ACAP were higher in male rats than in female rats overall (p<0.05). However, ACAP in the myocardium was significantly elevated in LS female rats compared to the MS and HS female rats, which had a significantly lower ACAP compared to all other groups. LS and MS training in both sexes and HS training (in females) led to significant decreases in the heart's lipid peroxidation. Amelioration of the lipid profile and reduction in oxidative damage contributed to a physiological state that benefits cardiovascular function in exercised animals. The results show that low and moderate intensity exercise promotes beneficial adaptations.

Plant zonation in a tropical irregular estuary: can large occurrence zones be explained by a tradeoff model?

Estuaries present an environmental gradient that ranges from almost fresh water conditions to almost marine conditions. Salinity and flooding are the main abiotic drivers for plants. Therefore, plant zonation in estuaries is closely related to the tidal cycles. It is expected that the competitive abilities of plants would be inversely related to the tolerance toward environmental stress (tradeoff). Thus, in estuaries, plant zonation tends to be controlled by the environment near the sandbar and by competition away from it. This zonation pattern has been proposed for regular non-tropical estuaries. For tropical estuaries, the relative importance of rain is higher, and it is not clear to what extent this model can be extrapolated. We measured the tidal influence along the environmental gradient of a tropical irregular estuary and quantified the relative importance of the environment and the co-occurrence degree. Contrary to the narrow occurrence zone that would be expected for regular estuaries, plants presented large occurrence zones. However, the relative importance of the environment and competition followed the same patterns proposed for regular estuaries. The environmental conditions allow plants to occur in larger zones, but these zones arise from smaller and infrequent patches distributed across a larger area, and most species populations are concentrated in relatively narrow zones. Thus, we concluded that the zonation pattern in the Massaguaçu River estuary agrees with the tradeoff model.

Oral L-arginine modulates blood lactate and interleukin-6 after exercise in HIV-infected men.

The acute administration of L-arginine (L-arg), a nitric oxide (NO) precursor, reduces lactate (LAC) concentration after exercise in healthy individuals. Lower concentration of L-arg may enhance the action of some inflammatory cytokines in HIV-1 infected patients. We tested the hypothesis that acute L-arg administration may reduce post-exercise blood LAC and inflammatory cytokines levels in HIV-infected patients. 10 HIV-infected men performed 2 maximal incremental cardiopulmonary exercise tests, separated by one week. 30 min before each test, patients received oral placebo or 20 g of L-arg, in random order. Blood LAC, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and interleukin-10 (IL-10) were measured before and up to 60 min after exercise. L-arg administration had no significant effect on exercise performance. Compared to placebo, L-arg administration reduced maximal post-exercise blood LAC from 8.7±0.6 to 6.9±0.4 mmol.L-1 (p<0.05). L-arg administration had no significant effect on TNF-alpha or IL-10 concentrations, but increased post-exercise IL-6 (placebo=19±3pg.mL-1; L-arg=63±8 pg.mL-1; p<0.05). In HIV-1 infected men, acute administration of L-arg reduces post-exercise blood LAC and increases IL-6 levels, suggesting the activation of the L-arg-NO pathway, with possible anti-inflammatory consequences.

Volume of supervised exercise training impacts glycaemic control in patients with type 2 diabetes: a systematic review with meta-regression analysis.

AIMS/HYPOTHESIS: Supervised exercise programmes improve glycaemic control in type 2 diabetes, but training characteristics associated with reduction in HbA(1c) remain unclear. We conducted a systematic review with meta-regression analysis of randomised clinical trials (RCTs) assessing the association between intensity and volume of exercise training (aerobic, resistance or combined) and HbA(1c) changes in patients with type 2 diabetes. METHODS: Five electronic databases were searched (1980-2012) to retrieve RCTs of at least 12 weeks' duration, consisting of supervised exercise training vs no intervention, that reported HbA(1c) changes and exercise characteristics. Two independent reviewers conducted study selection and data extraction. RESULTS: Twenty-six RCTs (2,253 patients) met the inclusion criteria. In multivariate analysis, baseline HbA(1c) and exercise frequency explained nearly 58% of between-study variance. Baseline HbA(1c) was inversely correlated with HbA(1c) reductions after the three types of exercise training. In aerobic training, exercise volume (represented by frequency of sessions) was associated with changes in HbA(1c) (weighted r = -0.64), while no variables were correlated with glycaemic control induced by resistance training. In combined training, weekly volume of resistance exercise explained heterogeneity in multivariate analysis and was associated with changes in HbA(1c) levels (weighted r = -0.70). CONCLUSIONS/INTERPRETATION: Reduction in HbA(1c) is associated with exercise frequency in supervised aerobic training, and with weekly volume of resistance exercise in supervised combined training. Therefore, exercise volume is a major determinant of glycaemic control in patients with type 2 diabetes.

Non-steroidal anti-inflammatory use in the XV Pan-American Games (2007).

BACKGROUND: non-steroidal anti-inflammatory drugs (NSAIDs) are frequently used in sports medicine to reduce time of incapacity. OBJECTIVE: to describe the frequency of NSAIDs use by athletes in the XV Pan-American Games. METHODS: all athletes who were tested by the anti-doping control filled a form. The voluntarily declared medications were recorded and categorised according to sport modality, sex, region and control situation according to the World Anti-Doping Agency. RESULTS: among the 1261 athletes tested (231 out-competition (OC) and 1030 in-competition (IC); 733 men and 528 women), 63% reported use of drugs, NSAIDs being the most frequently (64% of users) used medications. The use of medications was not significantly different between sexes or among different regions of the world. The number of users of only one type of NSAID was higher than those who used more than one type of NSAIDs or a combination with analgesics (335 vs 168 cases). IC reports presented higher use of NSAIDs than OC. CONCLUSION: athletes tested by the anti-doping control of the XV Pan-American Games reported a high frequency of NSAIDs use. The frequent utilisation in competition suggests that these medications might be used as ergogenic aid.

Effects of altering pedal frequency on the slow component of pulmonary VO2 kinetics and EMG activity.

This study investigated the effects of pedal frequency on the slow component of pulmonary oxygen uptake ( V O(2)) kinetics during heavy exercise at the same relative intensity. We hypothesized that higher pedal frequency (expected to enhance fast-twitch muscle fiber recruitment) would be associated with greater slow component amplitude (A' (s)), surface electromyography (normalized root mean square; RMS) and blood lactate concentration ([lactate]). Eight subjects performed square-wave transitions to heavy exercise at 35 and 115 rpm. Furthermore, alternated cadences square-wave transitions (35-115 rpm) were performed to examine the potential effects of additional fast-twitch muscle fiber recruitment on the slow component. Significance was accepted when P<0.05. The A' (s) was greater at higher cadences (0.58+/-0.08 and 0.70+/-0.09 L.min (-1) at 115 and 35-115 rpm, respectively) than at 35 rpm (0.35+/-0.04 L.min (-1)). Greater EMG increase over time (DeltaRMS ((10-3 min))) and [lactate] were observed at 115 and 35-115 rpm compared with 35 rpm. There was a significant correlation between A' (s) and overall DeltaRMS ((10-3 min)) for all pedal frequencies combined (r=0.63; P=0.001). Pedal frequency had no effect on time constants or time delays. These findings are consistent with the concept that progressive recruitment of muscle fibers is associated with the V O(2) slow component.

Acute electrophysiologic consequences of pyridostigmine inhibition of cholinesterase in humans

The cardiovascular electrophysiologic basis for the action of pyridostigmine, an acetylcholinesterase inhibitor, has not been investigated. The objective of the present study was to determine the cardiac electrophysiologic effects of a single dose of pyridostigmine bromide in an open-label, quasi-experimental protocol. Fifteen patients who had been indicated for diagnostic cardiac electrophysiologic study underwent two studies just before and 90-120 min after the oral administration of pyridostigmine (45 mg). Pyridostigmine was well tolerated by all patients. Wenckebach nodal anterograde atrioventricular point and basic cycle were not altered by pyridostigmine. Sinus recovery time (ms) was shorter during a 500-ms cycle stimulation (pre: 326 ± 45 vs post: 235 ± 47; P = 0.003) but not during 400-ms (pre: 275 ± 28 vs post: 248 ± 32; P = 0.490) or 600-ms (pre: 252 ± 42 vs post: 179 ± 26; P = 0.080) cycle stimulation. Pyridostigmine increased the ventricular refractory period (ms) during the 400-ms cycle stimulation (pre: 238 ± 7 vs post: 245 ± 9; P = 0.028) but not during the 500-ms (pre: 248 ± 7 vs post: 253 ± 9; P = 0.150) or 600-ms (pre: 254 ± 8 vs post: 259 ± 8; P = 0.255) cycle stimulation. We conclude that pyridostigmine did not produce conduction disturbances and, indeed, increased the ventricular refractory period at higher heart rates. While the effect explains previous results showing the anti-arrhythmic action of pyridostigmine, the clinical impact on long-term outcomes requires further investigation.

Acute electrophysiologic consequences of pyridostigmine inhibition of cholinesterase in humans.

The cardiovascular electrophysiologic basis for the action of pyridostigmine, an acetylcholinesterase inhibitor, has not been investigated. The objective of the present study was to determine the cardiac electrophysiologic effects of a single dose of pyridostigmine bromide in an open-label, quasi-experimental protocol. Fifteen patients who had been indicated for diagnostic cardiac electrophysiologic study underwent two studies just before and 90-120 min after the oral administration of pyridostigmine (45 mg). Pyridostigmine was well tolerated by all patients. Wenckebach nodal anterograde atrioventricular point and basic cycle were not altered by pyridostigmine. Sinus recovery time (ms) was shorter during a 500-ms cycle stimulation (pre: 326 +/- 45 vs post: 235 +/- 47; P = 0.003) but not during 400-ms (pre: 275 +/- 28 vs post: 248 +/- 32; P = 0.490) or 600-ms (pre: 252 +/- 42 vs post: 179 +/- 26; P = 0.080) cycle stimulation. Pyridostigmine increased the ventricular refractory period (ms) during the 400-ms cycle stimulation (pre: 238 +/- 7 vs post: 245 +/- 9; P = 0.028) but not during the 500-ms (pre: 248 +/- 7 vs post: 253 +/- 9; P = 0.150) or 600-ms (pre: 254 +/- 8 vs post: 259 +/- 8; P = 0.255) cycle stimulation. We conclude that pyridostigmine did not produce conduction disturbances and, indeed, increased the ventricular refractory period at higher heart rates. While the effect explains previous results showing the anti-arrhythmic action of pyridostigmine, the clinical impact on long-term outcomes requires further investigation.

Coronary artery disease in Brazil: contemporary management and future perspectives.

Cardiovascular diseases are responsible for 32% of total mortality in Brazil, mostly due to cerebrovascular and coronary artery disease. Epidemiological and socio-economical factors play a pivotal role on the distribution, severity and management of coronary artery disease, and the burden is greater in the southeast and south regions of the country, with a higher mortality in low-income populations. The Brazilian healthcare structure is divided into two complementary systems-public and private-but 75% of the population is covered exclusively by the public system. Some Brazilian institutions offer state-of-the-art care to patients with acute and chronic coronary artery disease, but regional inequalities in medical care are still significant. National policies will have to be implemented to fight risk factors, to ensure primary prevention strategies, including assistance on drugs with known protective effects, areas to be tackled by both the private and the public health sectors. Finally, large investments will have to be made to improve tertiary care, to reorganise systems of care for acute patients and mainly to ensure prompt access and continuity of cardiac care and secondary prevention strategies for the whole population.

Circuit weight training and cardiac morphology: a trial with magnetic resonance imaging.

BACKGROUND: Aerobic training (AT) and circuit weight training (CWT) improve peak oxygen uptake (VO(2)peak). During CWT the circulatory system is exposed to higher pressure, which could induce left ventricle morphological adaptations, possibly distinct from those derived from aerobic training. OBJECTIVE: To compare the effects of aerobic training and CWT upon morphological and functional cardiac adaptations detected by magnetic resonance imaging. METHODS: Twenty healthy sedentary individuals were randomly assigned to participate in a 12-week programme of aerobic training (n = 6), CWR (n = 7) or no intervention (n = 7, controls). Training programmes consisted of 36 sessions, 35 min each, 3 times per week, at 70% of maximal heart rate, and CWT included series of resistance exercises performed at 60% of 1 maximal repetition. Cardiopulmonary exercise testing and cardiac magnetic resonance imaging were performed before and after the intervention. RESULTS: There was a similar improvement in VO(2)peak following aerobic training (mean (SD) increment: 12 (4)%) and CWT (12 (4)%), while there was no change in the control group. Aerobic training (12 (6)%) and CWT (16 (5)%) improved strength in the lower limbs, and only CWT resulted in improvement of 13 (4)% in the strength of the upper limbs. However, there were no detectable changes in left ventricular mass, end-diastolic volume, stroke volume or ejection fraction. CONCLUSION: In previously sedentary individuals, short-term CWT and aerobic training induce similar improvement in functional capacity without any adaptation in cardiac morphology detectable by cardiac magnetic resonance imaging.

Acute water ingestion increases arterial blood pressure in hypertensive and normotensive subjects.

In patients with severe autonomic dysfunction, water ingestion elicits an acute pressor response. Hypertension may be associated with changes in cardiovascular autonomic modulation, but there is no information on the acute effects of water ingestion in patients with hypertension. In this study, we compared the effect of acute water ingestion on haemodynamic and autonomic responses of hypertensive and normotensive individuals. Eight patients with mild hypertension were compared to 10 normotensive individuals. After 30 min resting in the supine position all subjects ingested 500 ml of water. At baseline and after water ingestion, venous blood samples for plasma volume determination were collected, and electrocardiographic tracings, finger blood pressure, forearm blood flow and muscle sympathetic nerve activity (MSNA) were obtained. Water ingestion resulted in similar and minor reduction in plasma volume. Systolic and diastolic blood pressure increased in both hypertensive (mean+/-s.d.: 19/14+/-6/3 mm Hg) and normotensive subjects (17/14+/-6/3 mm Hg). There was an increase in forearm vascular resistance and in MSNA. Heart rate was reduced (hypertensive: 5+/-1 beats/min, normotensive: 5+/-6 beats/min) and the high-frequency component of heart rate and systolic blood pressure variability was increased. In hypertensive and normotensive individuals, acute water ingestion elicits a pressor response, an effect that is most likely determined by an increased vasoconstrictor sympathetic activity, and is counterbalanced by an increase in blood pressure and heart rate vagal modulation.

Abnormal response of left ventricular systolic function to submaximal exercise in post-partial left ventriculotomy patients.

Patients with heart failure who have undergone partial left ventriculotomy improve resting left ventricular systolic function, but have limited functional capacity. We studied systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculotomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Nine patients with heart failure previously submitted to partial left ventriculotomy were compared with 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise test with measurement of peak oxygen uptake and anaerobic threshold. Radionuclide left ventriculography was performed to analyze ejection fraction and peak filling rate at rest and during exercise at the intensity corresponding to the anaerobic threshold. Groups presented similar exercise capacity evaluated by peak oxygen uptake and at anaerobic threshold. Maximal heart rate was lower in the partial ventriculotomy group compared to the heart failure group (119 +/- 20 vs 149 +/- 21 bpm; P < 0.05). Ejection fraction at rest was higher in the partial ventriculotomy group as compared to the heart failure group (41 +/- 12 vs 32 +/- 9%; P < 0.0125); however, ejection fraction increased from rest to anaerobic threshold only in the heart failure group (partial ventriculotomy = 44 +/- 17%; P = non-significant vs rest; heart failure = 39 +/- 11%; P < 0.0125 vs rest; P < 0.0125 vs change in the partial ventriculotomy group). Peak filling rate was similar at rest and increased similarly in both groups at the anaerobic threshold intensity (partial ventriculotomy = 2.28 +/- 0.55 EDV/s; heart failure = 2.52 +/- 1.07 EDV/s; P < 0.0125; P > 0.05 vs change in partial ventriculotomy group). The abnormal responses demonstrated here may contribute to the limited exercise capacity of patients with partial left ventriculotomy despite the improvement in resting left ventricular systolic function.

Abnormal response of left ventricular systolic function to submaximal exercise in post-partial left ventriculotomy patients

Patients with heart failure who have undergone partial left ventriculotomy improve resting left ventricular systolic function, but have limited functional capacity. We studied systolic and diastolic left ventricular function at rest and during submaximal exercise in patients with previous partial left ventriculotomy and in patients with heart failure who had not been operated, matched for maximal and submaximal exercise capacity. Nine patients with heart failure previously submitted to partial left ventriculotomy were compared with 9 patients with heart failure who had not been operated. All patients performed a cardiopulmonary exercise test with measurement of peak oxygen uptake and anaerobic threshold. Radionuclide left ventriculography was performed to analyze ejection fraction and peak filling rate at rest and during exercise at the intensity corresponding to the anaerobic threshold. Groups presented similar exercise capacity evaluated by peak oxygen uptake and at anaerobic threshold. Maximal heart rate was lower in the partial ventriculotomy group compared to the heart failure group (119 ± 20 vs 149 ± 21 bpm; P < 0.05). Ejection fraction at rest was higher in the partial ventriculotomy group as compared to the heart failure group (41 ± 12 vs 32 ± 9 percent; P < 0.0125); however, ejection fraction increased from rest to anaerobic threshold only in the heart failure group (partial ventriculotomy = 44 ± 17 percent; P = non-significant vs rest; heart failure = 39 ± 11 percent; P < 0.0125 vs rest; P < 0.0125 vs change in the partial ventriculotomy group). Peak filling rate was similar at rest and increased similarly in both groups at the anaerobic threshold intensity (partial ventriculotomy = 2.28 ± 0.55 EDV/s; heart failure = 2.52 ± 1.07 EDV/s; P < 0.0125; P > 0.05 vs change in partial ventriculotomy group). The abnormal responses demonstrated here may contribute to the limited exercise capacity of patients with partial left ventriculotomy despite...

Estimation of the lactate threshold from heart rate response to submaximal exercise: the pulse deficit.

In this study, we evaluated the validity of a sharp increase in pulse deficit (PD) as a noninvasive index for estimation of the first lactate threshold (LT (1)) in healthy individuals with various levels of aerobic fitness. Three groups of healthy male subjects participated in the study: 15 sedentary individuals, 14 students of physical education, and 13 competitive athletes. Each subject performed a maximal incremental exercise test on the cycle ergometer for the determination of the LT (1), the second lactate threshold, and peak power output. On different days, subjects performed several 8-min bouts of constant-load exercise on the cycle ergometer, corresponding to each of the power outputs of the maximal test, to evaluate PD, which was calculated as the total number of heart beats of the last 4 min minus the total number of heart beats in the first 4 min of exercise. The three groups presented similar blood lactate, heart rate and pulse deficit responses to exercise. For the first power output up to the LT (1), PD showed no significant changes. For the three groups, a sharp increase in PD was seen at the intensity immediately above LT (1). There was a significant correlation between PD and blood lactate changes from the rest to 4th min of submaximal exercise (r = 0.83, p < 0.05). The power output before a sharp increase in PD detected during constant-load exercise (112 +/- 38 W) and the power output corresponding to the LT (1) detected during the incremental test (111 +/- 37 W, p = 0.323) were similar and strongly correlated (r = 0.99, p = 0.0001). The absolute cut-point value of 25 beats for PD had a sensitivity of 100 %, a specificity of 95 %, and a positive predictive value of 90 % for the detection of LT (1). The determination of PD provides an accurate noninvasive estimate of the LT (1) in healthy young men with different levels of fitness. One 8-min submaximal exercise bout can establish if an individual is exercising above or below the LT (1).

[Disability and quality of life of stroke survivors: evaluation nine months after discharge]. / Incapacidad y calidad de vida del paciente afectado por un accidente vascular cerebral: evaluación nueve meses después del alta hospitalaria.

INTRODUCTION AND AIM: After acute episode, a great number of individuals who survive a stroke have impairments that impede them to carry out with autonomy a set of basic activities of daily life and instrumental activities of daily life. The clinical evaluation health self perception is a useful element on patient's recovering process. The purpose of this study was to evaluate post-stroke functional health status and quality of life. PATIENTS AND METHODS: After identification of a cohort of admitted patients at a general hospital, those were contacted by phone nine months after discharge. The collected tool sent by mail included the COOP WONCA charts, Frenchay Activities Index, Barthel Index, Rankin scale and a set of socio-demographic variables. RESULTS: Participants survival rate was of 81%. The physical functioning and the capacity to perform daily activities were the most affected ones, impairing the patients of making a set of basic and instrumental daily activities. The emotional state and health self-perception are also correlated to disability. CONCLUSIONS: The results suggest a significative percentage of stroke survivors maintaining a moderate or severe disability (47.8%) requiring the presence of caregiver helping self-care. Collected data enhances that stroke survivors have severe physical dysfunction associated to emotional and psychological disturbances.

Incapacidad y calidad de vida del paciente afectado por un accidente vascular cerebral: evaluación nueve meses después del alta hospitalaria / Disability and quality of life of stroke survivors: evaluation nine months after discharge

Introducción y objetivos. Tras el episodio agudo de accidentevascular cerebral (AVC), un gran número de supervivientesse ve afectado por secuelas que impiden llevar a cabo diversas actividadesbásicas o instrumentales de la vida diaria. Junto con laevaluación clínica, la percepción del paciente relativa a su estadode salud constituye una información útil en su proceso de recuperación.El objetivo de este estudio se centró en evaluar la capacidadfuncional y la calidad de vida tras el AVC. Pacientes y métodos.Tras la identificación de una cohorte de pacientes atendidos en unhospital general, se contactó con ellos nueve meses después del altahospitalaria. El instrumento de recogida de datos, enviado porcorreo, integraba la escala de COOP WONCA, el índice de actividadesde Frenchay, el índice de Barthel y la escala de Rankin, ademásde un conjunto de variables sociodemográficas. Resultados. Latasa de supervivencia de los participantes fue del 81%. La aptitudfísica y la capacidad para ejecutar actividades diarias son lasdimensiones físicas más afectadas, que impiden a los pacientes realizarun conjunto de actividades básicas e instrumentales diarias.El estado afectivo-emocional y la autopercepción del estado generalde salud se correlacionan igualmente con la incapacidad física.Conclusiones. Los resultados apuntan a un porcentaje significativode individuos que tras el AVC mantienen una incapacidad moderadao grave (47,8%), lo cual determina la presencia de una segundapersona para colaborar en las actividades de autocuidado. Los datosencontrados son decisivos en cuanto a que los individuos presentandisfunciones físicas graves asociadas a alteraciones emocionalesy psicológicas

Introduction and aim. After acute episode, a great number of individuals who survive a stroke have impairmentsthat impede them to carry out with autonomy a set of basic activities of daily life and instrumental activities of daily life. Theclinical evaluation health self perception is a useful element on patient’s recovering process. The purpose of this study was toevaluate post-stroke functional health status and quality of life. Patients and methods. After identification of a cohort ofadmitted patients at a general hospital, those were contacted by phone nine months after discharge. The collected tool sent bymail included the COOP WONCA charts, Frenchay Activities Index, Barthel Index, Rankin scale and a set of sociodemographicvariables. Results. Participants survival rate was of 81%. The physical functioning and the capacity to performdaily activities were the most affected ones, impairing the patients of making a set of basic and instrumental daily activities.The emotional state and health self-perception are also correlated to disability. Conclusions. The results suggest asignificative percentage of stroke survivors maintaining a moderate or severe disability (47.8%) requiring the presence ofcaregiver helping self-care. Collected data enhances that stroke survivors have severe physical dysfunction associated toemotional and psychological disturbances

[Hybrid or continuous renal replacement techniques for unstable haemodynamic patients in the intensive care unit]. / Técnicas dialíticas híbridas ou hemodiafiltração para doentes hemodinâmicamente instáveis em cuidados intensivos.

OBJECTIVE: Comparative study to evaluate the impact of a hybrid renal replacement technique (HRRT) vs a continuous renal replacement technique (haemodiafiltration) on hemodynamic tolerance, azotemic control, and mortality in critical care patients with acute renal failure. SETTING: a 14-bed Intensive Care Unit (ICU). MATERIAL AND METHODS: Two groups of patients were retrospectively compared: patients submitted to continuous renal replacement techniques (CRRT) in 2003 (n = 26) and patients who underwent HRRT in 2004 (n = 27). Both groups had similar severity scores and underlying diseases, and were haemodynamically unstable. Urea and creatinine reduction ratio (URR and CRR) in both groups were evaluated. RESULTS: Patients treated with HRRT presented a lower mortality (62% vs 84%), less heparin use, and a higher URR and CRR. Univariate logistic regression showed that an increase in APACHE II was related to an increase in mortality (CI 95%, 1.03-1.26). Odds for mortality for CRRT group were about 3 times higher (CI 95%, 0.86-12.11), but not statistically significant (p = 0.074). CONCLUSION: HRRT is a valid alternative to CRRT in haemodynamically unstable critically ill patients.