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.

Prevalência de infecção nosocomial em Unidades de Terapia Intensiva do Rio Grande do Sul / The prevalence of nosocomial infection in Intensive Care Units in the State of Rio Grande do Sul

JUSTIFICATIVA E OBJETIVOS: Determinar a prevalência de infecções adquiridas em UTI e os fatores de risco para estas infecções, identificar os organismos infectantes mais prevalentes, avaliar a relação entre infecção adquirida na UTI e mortalidade. MÉTODO: Estudo de prevalência de um dia. Participaram do estudo 16 UTI do estado do Rio Grande do Sul, excluindo unidades coronarianas ou pediátricas. Todos os pacientes com idade maior que 12 anos, ocupando um leito de UTI por um período de 24h, foram incluídos. As 16 UTI coletaram dados de 174 pacientes. Principais desfechos: taxas de infecção adquirida na UTI, padrões de resistência dos patógenos isolados e fatores potenciais de risco para infecção adquirida na UTI e mortalidade. RESULTADOS: Um total de 122 pacientes (71 por cento) estava infectado, e 51 (29 por cento) adquiriram infecção na UTI. Pneumonia (58,2 por cento), infecção do trato respiratório inferior (22,9 por cento), infecção do trato urinário (18 por cento) foram os tipos mais freqüentes de infecção. Os microorganismos mais relatados foram stafilococos aureus (42 por cento [64 por cento resistentes a oxacilina]) e pseudomonas aeruginosa (31 por cento). Seis fatores de risco foram identificados para infecção adquirida na UTI: cateter urinário, acesso vascular central, intubação traqueal por tempo prolongado (> 4 dias), doença crônica, trauma e internação prolongada na UTI (> 30 dias). Os fatores de risco associados à morte foram idade, APACHE II, falência orgânica e prótese em via aérea com ou sem ventilação mecânica. CONCLUSÕES: A infecção adquirida na UTI é comum e freqüentemente associada a isolados de microorganismos resistentes. Este estudo, apesar de sua abrangência regional, serve de referência epidemiológica para ajudar a programar políticas de controle de infecção.

BACKGROUND AND OBJECTIVES: To determine the prevalence of intensive care unit (ICU)-acquired infections and the risk factors for these infections, identify the predominant infecting organisms, and evaluate the relationship between ICU-acquired infection and mortality. METHODS: A 1-day point prevalence study. Sixteen ICU of the State of Rio Grande do Sul-Brazil, excluding coronary care and pediatric units. All patients < 12 yrs occupying an ICU bed over a 24-hour period. The 16 ICU provided 174 case reports. Main outcomes: rates of ICU-acquired infection, resistance patterns of microbiological isolates, and potential risks factors for ICU-acquired infection and death. RESULTS: A total of 122 patients (71 percent) was infected and 51 (29 percent) had ICU-acquired infection. Pneumonia (58.2 percent), lower tract respiratory infection (22.9 percent), urinary tract infection (18 percent) were the most frequents types of ICU infection. Most frequently microorganisms reported were staphylococcus aureus (42 percent [64 percent resistant to oxacilin]) and pseudomonas aeruginosa (31 percent). Six risk factors for ICU acquired infection were identified: urinary catheterization, central vascular line, tracheal intubation for prolonged time (> 4 days), chronic disease and increased length of ICU stay (> 30 days). The risks factors associated with death were age, APACHE II, organ dysfunction, and tracheal intubation with or without mechanical ventilation. CONCLUSIONS: ICU-acquired infection is common and often associated with microbiological isolates of resistant organisms. This study may serve as an epidemiological reference to help the discussion of regional infection control policies.