Mechanical ventilation in patients in the intensive care unit of a general university hospital in southern Brazil: an epidemiological study

OBJECTIVES: To determine the characteristics, the frequency and the mortality rates of patients needing mechanical ventilation and to identify the risk factors associated with mortality in the intensive care unit (ICU) of a general university hospital in southern Brazil. METHOD: Prospective cohort study in patients admitted to the ICU who needed mechanical ventilation for at least 24 hours between March 2004 and April 2007. RESULTS: A total of 1,115 patients admitted to the ICU needed mechanical ventilation. The mortality rate was 51%. The mean age (± standard deviation) was 57±18 years, and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 22.6±8.3. The variables independently associated with mortality were (i) conditions present at the beginning of mechanical ventilation, age (hazard ratio: 1.01; p<0.001); the APACHE II score (hazard ratio: 1.01; p<0.005); acute lung injury/acute respiratory distress syndrome (hazard ratio: 1.38; p=0.009), sepsis (hazard ratio: 1.33; p=0.003), chronic obstructive pulmonary disease (hazard ratio: 0.58; p=0.042), and pneumonia (hazard ratio: 0.78; p=0.013) as causes of mechanical ventilation; and renal (hazard ratio: 1.29; p=0.011) and neurological (hazard ratio: 1.25; p=0.024) failure, and (ii) conditions occurring during the course of mechanical ventilation, acute lung injuri/acute respiratory distress syndrome (hazard ratio: 1.31; p<0.010); sepsis (hazard ratio: 1.53; p<0.001); and renal (hazard ratio: 1.75; p<0.001), cardiovascular (hazard ratio: 1.32; p≤0.009), and hepatic (hazard ratio: 1.67; p≤0.001) failure. CONCLUSIONS: This large cohort study provides a comprehensive profile of mechanical ventilation patients in South America. The mortality rate of patients who required mechanical ventilation was higher, which may have been related to the severity of illness of the patients admitted to our ICU. Risk factors for hospital mortality included conditions present at the start of mechanical ventilation conditions that occurred during mechanical support.

The role of serum lactate in post-cardiac arrest syndrome

Cardiopulmonary arrest is a medical emergency with significant mortality. The success of resuscitation led to the emergence of post-cardiac arrest syndrome (PCAS), which originates from ischemia-reperfusion injury and its consequent increase in serum lactate. Despite the robust evidence correlating hyperlactatemia as a prognostic marker in critically ill patients, there is insufficient evidence about the role of serum lactate in the outcome of PCAS. Thus, the purpose of this review is to check the current evidence on the role of lactate in predicting mortality in PCAS.

Diretrizes para o manejo do tétano acidental em pacientes adultos / Guidelines for the management of accidental tetanus in adult patients

O tétano acidental, a despeito de ser uma doença prevenível por imunização, ainda é frequente nos países subdesenvolvidos e em desenvolvimento. Sua letalidade ainda é elevada e os estudos sobre a melhor forma de tratamento são escassos. Tendo em vista esta escassez e a importância clínica dessa doença, um grupo de especialistas reunidos pela Associação de Medicina Intensiva Brasileira (AMIB), desenvolveu recomendações baseadas na melhor evidencia disponível para o manejo do tétano no paciente necessitando cuidados intensivos. As recomendações incluem aspectos relativos à admissão do paciente tetânico na unidade de terapia intensiva, tratamento com imunoglobulinas, tratamento antibiótico, manejo da analgossedação e bloqueio neuromuscular, manejo da disautonomia e especificidades na ventilação mecânica e fisioterapia nesta população especial.

Although tetanus can be prevented by appropriate immunization, accidental tetanus continues to occur frequently in underdeveloped and developing countries. Tetanus mortality rates remain high in these areas, and studies regarding the best therapy for tetanus are scarce. Because of the paucity of data on accidental tetanus and the clinical relevance of this condition, the Associação de Medicina Intensiva Brasileira (AMIB) organized a group of experts to develop these guidelines, which are based on the best available evidence for the management of tetanus in patients requiring admission to the intensive care unit. The guidelines discuss the management of tetanus patients in the intensive care unit, including the use of immunoglobulin therapy, antibiotic therapy, management of analgesics, sedation and neuromuscular blockade, management of dysautonomia and specific issues related to mechanical ventilation and physiotherapy in this population.

Echocardiographic evaluation during weaning from mechanical ventilation

INTRODUCTION: Echocardiographic, electrocardiographic and other cardiorespiratory variables can change during weaning from mechanical ventilation. OBJECTIVES: To analyze changes in cardiac function, using Doppler echocardiogram, in critical patients during weaning from mechanical ventilation, using two different weaning methods: pressure support ventilation and T-tube; and comparing patient subgroups: success vs. failure in weaning. METHODS: Randomized crossover clinical trial including patients under mechanical ventilation for more than 48 h and considered ready for weaning. Cardiorespiratory variables, oxygenation, electrocardiogram and Doppler echocardiogram findings were analyzed at baseline and after 30 min in pressure support ventilation and T-tube. Pressure support ventilation vs. T-tube and weaning success vs. failure were compared using ANOVA and Student's t-test. The level of significance was p<0.05. RESULTS: Twenty-four adult patients were evaluated. Seven patients failed at the first weaning attempt. No echocardiographic or electrocardiographic differences were observed between pressure support ventilation and T-tube. Weaning failure patients presented increases in left atrium, intraventricular septum thickness, posterior wall thickness and diameter of left ventricle and shorter isovolumetric relaxation time. Successfully weaned patients had higher levels of oxygenation. CONCLUSION: No differences were observed between Doppler echocardiographic variables and electrocardiographic and other cardiorespiratory variables during pressure support ventilation and T-tube. However cardiac structures were smaller, isovolumetric relaxation time was larger, and oxygenation level was greater in successfully weaned patients.

Valor da enolase específica do neurônio como indicador de prognóstico pós-parada cardiorrespiratória / Serum neuron-specific enolase as a prognostic marker after a cardiac arrest

JUSTIFICATIVA E OBJETIVOS: A parada cardíaca é um estado de grave hipoperfusão cerebral. Os pacientes que sobrevivem a uma reanimação cardiorrespiratória estão sob grande risco de vir a morrer ou desenvolver lesão cerebral incapacitante, inclusive estado vegetativo persistente. Uma definição precoce do prognóstico desses pacientes tem implicações éticas e econômicas. O objetivo desse estudo foi revisar o valor prognóstico da Enolase Específica do Neurônio (NSE) em predizer precocemente os desfechos de pacientes após uma parada cardíaca. CONTEÚDO: A lesão cerebral permanente é a complicação mais temida de uma reanimação cardíaca prolongada. Muitos estudos têm tentado isolar fatores prognósticos que possam estar associados com desfechos clínicos em pacientes sobreviventes de parada cardíaca. Indicadores bioquímicos de morte neuronal parecem promissores nesse cenário. Nesse contexto, a NSE vem sendo estudada em pacientes reanimados de paradas cardíacas e níveis elevados dessa enzima sugerem lesão encefálica mais extensa e estão associados a desfechos clínicos desfavoráveis. CONCLUSÕES: Os desfechos depois de uma parada cardíaca são determinados principalmente pelo grau de lesão cerebral isquêmica e medidas precoces de NSE sérica podem ser um método adjunto de grande valor na avaliação prognóstica desses pacientes.

BACKGROUND AND OBJECTIVES: Cardiac arrest is a state of severe cerebral perfusion deficit. Patients recovering from a cardiopulmonary resuscitation are at great risk of subsequent death or incapacitating neurologic injury, including persistent vegetative state. The early definition of prognosis for these patients has ethical and economic implications. The main purpose of this manuscript was to review the prognostic value of serum Neuron-Specific Enolase (NSE) in predicting outcomes in patients early after a cardiac arrest. CONTENTS: Severe neurologic disability is the most feared complication after a cardiac arrest. Many studies are trying to find prognostic markers that can be associated with outcomes in patients surviving a cardiac arrest. Biochemical markers of neuronal injury seem to be promising in this scenario. Therefore, NSE levels have been studied in patients after a cardiac arrest and high enzyme levels suggest more extensive brain damage and are associated with unfavorable clinical outcomes. CONCLUSIONS: Outcome after a cardiac arrest is mostly determined by the degree of hypoxic brain damage and early determinations of serum NSE level can be a valuable ancillary method for assessing outcome in these patients.

Ressuscitação cardiorrespiratória / Cardiorespiratory resuscitation

A ressuscitação cardiorrespiratória inclui todos os procedimentos que devem ser adotados para manejar uma situação de parada cardiorrespiratória, incluindo o suporte básico e avançado de vida. O suporte básico de vida inclui o ABCD primário (A - avaliar consciência, ativar sistema de emergência e avaliar respiração; B - realizar duas ventilações lentas; C - avaliar circulação e iniciar compressões torácicas; D - desfibrilação). O suporte avançado de vida inclui o ABCD secundário, que consta de: A - colocar dispositivo de via aérea; B - ventilar com pressão positiva e oxigenar adequadamente; C - garantir circulação: acesso venoso, drogas vasopressoras, considerar antiarrítmicos, tampões, marca-passo; D - diagnóstico do tipo de parada cardiorrespiratória e diagnóstico diferencial, procurando e tratando causas reversíveis de parada cardiorrespiratória. O acesso rápido ao sistema médico de emergências, a ressuscitação cardiorrespiratória e a desfibrilação rápidas (que integram o suporte básico de vida) e o suporte avançado de vida formam a “cadeia de sobrevida”, cujos quatro elos ilustram a interdependência entre os elementos de uma resposta de emergência para conseguir uma sobrevivência ótima das vítimas de parada cardíaca intra e extra-hospitalar

Doença de Still do adulto: uma causa pouco comum de febre de origem indeterminada / An uncommon cause of fever of unknown origin

Os autores ilustram a dificuldade para se estabelecer o diagnóstico em um paciente com febre de origem indeterminada. Relatam um caso de doença de Still do adulto, diagnosticada após intensa investigaçäo hospitalar. Concluem que a doença de Still do adulto, embora contribua com uma parcela relativamente baixa dentro das causas de febre de origem indeterminada, deve ser lembrada, pois o seu reconhecimento precoce permite poupar o paciente de uma investigaçäo invasiva e dispendiosa, da mesma forma que possibilita a oferta de um tratamento efetivo.