Anna Maria Buehler

Como avaliar criticamente revisões sistemáticas e metanálises

BACKGROUND AND OBJECTIVES: Systematic reviews are important knowledge generating tools to help the decision making process in the Critical Care Unit. This narrative aims to describe the important elements used to critically appraise intensive care-related systematic reviews. CONTENTS: When critically assessing systematic reviews, one should pay particular attention to the importance and appropriateness of the research question, the search strategy, the inclusion criteria and methodological quality of the studies included, and the methods of data extraction. In addition, a relevant systematic review must have consistent data (in case of a meta-analysis) or the cause of the heterogeneity must have been adequately explored, and results must be applicable in critical patients. CONCLUSIONS: To apply correctly the available scientific evidence, one should critically assess data quality of systematic reviews, selecting the relevant information to manage the critically ill patient.

Echocardiography for prognostication during the resuscitation of intensive care unit patients with non-shockable rhythm cardiac arrest

AIM Transthoracic echocardiography (TTE) during cardiopulmonary arrest (CPA) has been studied in victims of cardiac arrests. Our objective was to evaluate the feasibility and usefulness of TTE in victims of cardiac arrest with non-shockable rhythms hospitalized in intensive care units (ICUs). METHODS This prospective and observational cohort study evaluated ICU patients with CPA in asystole or pulseless electrical activity (PEA). Intensivists performed TTE during intervals of up to 10s as established in the treatment protocol. Myocardial contractility was defined as intrinsic movement of the myocardium coordinated with cardiac valve movement. PEA without contractility was classified as electromechanical dissociation (EMD), and with contractility as pseudo-EMD. The images, the rates of return of spontaneous circulation (ROSC) and the survival upon hospital discharge and after 180 days were evaluated. RESULTS A total of 49 patients were included. Image quality was considered adequate in all cases and contributed to the diagnosis of CPA in 51.0% of the patients. Of the 49 patients included, 17 (34.7%) were in asystole and 32 (65.3%) in PEA, among which 5 (10.2%) were in EMD and 27 (55.1%) in pseudo-EMD. The rates of ROSC were 70.4% for those in pseudo-EMD, 20.0% for those in EMD, and 23.5% for those in asystole. Survival upon hospital discharge and after 180 days occurred only in patients in pseudo-EMD (22.2% and 14.8%, respectively). CONCLUSIONS TTE conducted during cardiopulmonary resuscitation in ICU patients can be performed without interfering with care protocols and can contribute to the differential diagnosis of CPA and to the identification of a subgroup of patients with better prognosis.

Effect of Tight Blood Glucose Control Versus Conventional Control in Patients with Type 2 Diabetes Mellitus: A Systematic Review with Meta-Analysis of Randomized Controlled Trials.

Tight control of blood glucose reduces cardiovascular events and total mortality is conflicting. To summarize clinical effects of tight versus conventional glucose control in patients with type 2 diabetes. We systematically searched MEDLINE, EMBASE, Cochrane Library, and ISI Web of Knowledge with no limits of language and time. Further trials were searched from the reference lists of identified studies. We included randomized controlled comparing different levels of blood glucose control intensity in type 2 diabetic patients. Two independent reviewers extracted data of eligible studies using standard case report forms. We investigated total mortality, cardiovascular and microvascular events, and hypoglycemia in patients with type 2 diabetes. We used random-effects models to obtain relative risks (RR) with 95% confidence intervals (CI). We included 6 trials involving 27,654 patients. There was no significant effect of tight blood glucose control on all-cause mortality (RR 1.03; 95% CI 0.90-1.17) or cardiovascular mortality (RR 1.04; 95% CI 0.83-1.29). Tight glucose control reduced the risk for nonfatal MI (RR 0.85; 95% CI 0.76-0.95), although had no effect on the incidence of nonfatal stroke (RR 1.02; 95% CI 0.88-1.17). For microvascular events, tight glucose control reduced the risk progression of retinopathy (RR 0.80; 95% CI 0.71-0.91), incidence of peripheral neuropathy (RR 0.94; 95% CI 0.89-0.99), and progression of nephropathy (RR 0.55; 95% CI 0.37-0.80), but had not significant effect on the incidence of nephropathy (RR 0.69; 95% CI 0.42-1.14). The risk of severe hypoglycemia increased with tight glucose control (RR 2.39; 95% CI 1.79-3.18). Tight blood glucose control reduces the risk for some macrovascular and microvascular events, without effect on all-cause mortality and cardiovascular mortality. Tight glucose control increases the risk of severe hypoglycemia.

Acetylcysteine for the Prevention of Renal Outcomes in Patients With Diabetes Mellitus Undergoing Coronary and Peripheral Vascular Angiography A Substudy of the Acetylcysteine for Contrast-Induced Nephropathy Trial

Background—Diabetes mellitus represents an independent risk factor for contrast-induced acute kidney injury. We report the results of a prespecified substudy of patients with diabetes mellitus included in the Acetylcysteine for Contrast-Induced Nephropathy Trial (ACT), the largest randomized study evaluating the effects of acetylcysteine for the prevention of contrast-induced acute kidney injury conducted to date. Methods and Results—From the 2308 patients included in the ACT, 1395 had diabetes mellitus and were considered for the present analysis. The study drugs (acetylcysteine 1200 mg or matching placebo) were administered orally twice daily for 2 doses before and 2 doses after the procedure. The allocation was concealed (central Web-based randomization). Participants, healthcare staff, data collectors, and outcome assessors were blinded. All analysis followed the intention-to-treat principle. The incidence of contrast-induced acute kidney injury (primary end point) was 13.8% in the acetylcysteine group and 14.7% in the control group (relative risk 0.93; 95% confidence interval, 0.69–1.26; P=0.64). A combined end point of death or need for dialysis at 30 days was also similar in both the groups (2.2% and 2.1%, respectively; hazard ratio, 1.07; 95% confidence interval, 0.52–2.19; P=0.86). Conclusions—In this subanalysis, acetylcysteine did not reduce the risk of contrast-induced acute kidney injury or other clinically relevant outcomes in patients with diabetes mellitus undergoing coronary and peripheral vascular angiography. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00736866.

Angioplastia guiada por ultrassom intracoronariano: metanálise de ensaios clínicos randomizados

Background The impact of intravascular ultrasound (IVUS) use on stenting has shown inconclusive results. Objective Systematic review and meta-analysis of the impact of IVUS on stenting regarding the clinical and angiographic evolution. Methods A search was performed in Medline/Pubmed, CENTRAL, Embase, Lilacs, Scopus and Web of Science databases. It included randomized clinical trials (RCTs) that evaluated the implantation of stents guided by IVUS, compared with those using angiography alone (ANGIO). The minimum follow-up duration was six months and the following outcomes were assessed: thrombosis, mortality, myocardial infarction, percutaneous and surgical revascularization, major adverse cardiovascular events (MACE) and restenosis. The binary outcomes were presented considering the number of events in each group; the estimates were generated by a random effects model, considering Mantel-Haenszel statistics as weighting agent and magnitude of effect for the relative risk (RR) with its respective 95% confidence interval (95%CI). Higgins I2 test was used to quantify the consistency between the results of each study. Results A total of 2,689 articles were evaluated, including 8 RCTs. There was a 27% reduction in angiographic restenosis (RR: 0.73, 95% CI: 0.54-0.97, I2 = 51%) and statistically significant reduction in the rates of percutaneous revascularization and overall (RR: 0.88; 95% CI: 0.51 to 1.53, I2 = 61%, RR: 0.73, 95% CI: 0.54 to 0.99, I2 = 55%), with no statistical difference in surgical revascularization (RR: 0.95, 95% CI: 0.52-1.74, I2 = 0%) in favor of IVUS vs. ANGIO. There were no differences regarding the other outcomes in the comparison between the two strategies. Conclusion Angioplasty with stenting guided by IVUS decreases the rates of restenosis and revascularization, with no impact on MACE, acute myocardial infarction, mortality or thrombosis outcomes.

Effects of Brazilian Cardioprotective Diet Program on risk factors in patients with coronary heart disease: a Brazilian Cardioprotective Diet randomized pilot trial

OBJECTIVE: To evaluate the effectiveness of the Brazilian Cardioprotective Diet Program in reducing blood pressures, fasting glucose levels and body mass indices in patients with established atherothrombotic disease. METHOD: This randomized controlled pilot trial included outpatients who were over 45 years of age with atherothrombotic cardiovascular disease. Group A, who received the Brazilian Cardioprotective Diet Program, had weekly sessions with dietitians. Groups B and C received the usual dietary therapy that is given to patients with cardiovascular diseases as proposed by the Brazilian guidelines. This diet had the same nutrient profile as that given to Group A, but it was customized by the integration of typical Mediterranean foods. The difference between Groups B and C was the number of sessions with the dietitian. Group B received weekly sessions, while group C only had monthly sessions. ClinicalTrials.gov: NCT 01453166. RESULTS: There was a greater reduction in systolic (7.8%) and diastolic (10.8%) blood pressures in Group A compared with Group B (2.3% and 7.3%), and Group C (3.9% and 4.9%, respectively). Fasting glucose decreased by 5.3% and 2% in Groups A and B, respectively. Fasting glucose increased by 3.7% in Group C. The BMIs decreased by 3.5% and 3.3% in Groups A and B, respectively. Group C did not present with any changes in BMI. However, none of these data showed statistical differences between the groups, which is methodologically acceptable in pilot trials. CONCLUSIONS: The Brazilian Cardioprotective Diet Program seems to be more effective in reducing blood pressures, fasting glucose levels, weights and BMIs in patients with previous cardiovascular disease compared with the diet that has been proposed by the Brazilian guidelines.

Is there evidence for recommending specific intravenous immunoglobulin formulations? A systematic review of head-to-head randomized controlled trials

Intravenous immunoglobulins (IVIG) have been used for several licensed and off-label indications. Each IVIG product is a unique formulation of IgG and excipients, making them distinct products. How these differences impact on individual IVIG product efficacy and safety are not well established but can be investigated by head-to-head randomized controlled trials (RCT). A systematic review of head-to-head RCT comparing different formulations of IVIG, regardless of the target condition and outcomes investigated. Two reviewers screened 4084 citations retrieved from MEDLINE, Embase, Cochrane and LILACS, and 23 citations were fully-text evaluated. Eight trials were included. The clinical conditions, outcomes and risk of bias were assessed. Of the eight trials included only two investigated products that are currently on the market. One evaluated two Grifols brands used in patients with primary immunodeficiency and another evaluated two Baxter brands used in patients with chronic inflammatory demyelinating polyradiculoneuropathy. There were no differences between the formulations for the outcomes evaluated. In the other trials, either the manufacturers were acquired by other companies or the formulation was withdrawn from the market. As consequence, evidence concerning these products could not be considered. The quality of the studies was low, showing high risk of bias. Direct evidence about the different IVIGs is scarce and, at present, there is no scientific evidence that can be applied for a specific brand or formulation. Further comparative effectiveness studies are highly desirable for a better understanding of the differences in safety and efficacy of IVIGs.

Endovascular thrombectomy for the treatment of acute ischemic stroke

UNLABELLED Few patients benefit from the current standard treatment for acute ischemic stroke (AIS), encouraging the development of new treatments. OBJECTIVE To systematically review the literature on the efficacy and/or safety of endovascular thrombectomy in AIS compared to standard treatment and to identify ongoing randomized controlled trials (RCTs). METHOD Searches for RCTs were performed in Medline/Embase, and for ongoing trials: International Clinical Trial Registry Platform, Clinicaltrials.gov and ISRCTN registry (to June 15th, 2015). RESULTS From the eight published RCTs, five showed the superiority of treatment that includes thrombectomy compared to standard care alone. From the 13 ongoing RCTs, 3 have been halted, one has not started, one has unknown status and eight will end between 2016 - 2020. CONCLUSION Evidence favours a combination of the standard therapy with endovascular thrombectomy. The selection criteria however limit the number of people who can benefit. Further studies are needed to prove its cost-effectiveness.

Como avaliar criticamente estudos de coorte em terapia intensiva

BACKGROUND AND OBJECTIVES: Cohort studies are useful to identify risk and prognostic factors, assess disease natural history and verify the impact of diagnostic or therapeutic interventions. This article aims to guide readers on how to critically assess papers using a cohort research design. CONTENTS: For a critical appraisal of cohort studies, one must observe: the existence of selection and information bias, the continuity of the follow-up, the control of confounding variables, the significance of the results and its applicability in clinical practice. CONCLUSIONS: Knowledge of factors which affect the quality of cohort studies allows intensive care professionals to select the best available evidence to guide the decision making process.

Como avaliar criticamente um ensaio clínico de alocação aleatória em terapia intensiva

Ensaios clinicos aleatorizados sao investigacoes cientificas consideradas padrao-ouro para avaliar intervencoes terapeuticas. Ensaios clinicos aleatorizados podem examinar e avaliar a seguranca e eficacia de novas drogas ou procedimentos terapeuticos ou comparar os efeitos entre duas ou mais drogas ou qualquer outra intervencao. Nesse artigo apresentamos as caracteristicas essenciais e fatores que podem introduzir vies nesses estudos. Em seguida, apresentamos criterios para avaliacao critica de artigos reportando os resultados de ensaios clinicos aleatorizados e mostramos como interpretar e aplica-los a pratica clinica.