Accuracy of different methods for blood glucose measurement in critically ill patients / Acurácia de diferentes métodos para mensuração de glicemia em pacientes graves

Context and objective: Although glucometers have not been validated for intensive care units, they are regularly used. The aim of this study was to compare and assess the accuracy and clinical agreement of arterial glucose concentration obtained using colorimetry (Agluc-lab), capillary (Cgluc-strip) and arterial (Agluc-strip) glucose concentration obtained using glucometry and central venous glucose concentration obtained using colorimetry (Vgluc-lab). Design and setting: Cross-sectional study in a university hospital. Method: Forty patients with septic shock and stable individuals without infection were included. The correlations between measurements were assessed both in the full sample and in subgroups using noradrenalin and presenting signs of tissue hypoperfusion. RESULTS: Cgluc-strip showed the poorest correlation (r = 0.8289) and agreement (-9.87 ± 31.76). It exceeded the limits of acceptable variation of the Clinical and Laboratory Standards Institute in 23.7 percent of the cases, and was higher than Agluc-lab in 90 percent of the measurements. Agluc-strip showed the best correlation (r = 0.9406), with agreement of -6.75 ± 19.07 and significant variation in 7.9 percent. For Vgluc-lab, r = 0.8549, with agreement of -4.20 ± 28.37 and significant variation in 15.7 percent. Significant variation was more frequent in patients on noradrenalin (36.4 percent versus 6.3 percent; P = 0.03) but not in the subgroup with hypoperfusion. There was discordance regarding clinical management in 25 percent, 22 percent and 15 percent of the cases for Cgluc-strip, Vgluc-lab and Agluc-strip, respectively. Conclusion: Cgluc-strip should be avoided, particularly if noradrenalin is being used. This method usually overestimates the true glucose levels and gives rise to management errors. CLINICAL TRIAL REGISTRATION: ACTRN12608000513314 (registered as an observational, cross-sectional study).

Contexto e objetivo: Apesar de glicosímetros não serem validados para unidades de terapia intensiva (UTI), seu uso é corriqueiro. O objetivo foi avaliar a acurácia e concordância clínica entre a glicemia arterial por colorimetria (glicA-lab), glicemias capilar (glicC-fita) e arterial (glicA-fita) por glicosimetria, e venosa central por colorimetria (glicV-lab). Tipo de estudo e local: Estudo transversal realizado em hospital universitário. Método: Foram incluídos 40 pacientes com choque séptico e indivíduos estáveis, sem infecção. A correlação entre medidas foi avaliada tanto na amostra global quanto nos subgrupos em uso de noradrenalina e com sinais de hipoperfusão tecidual. Resultados: A glicC-fita mostrou pior correlação (r = 0,8289) e concordância (-9,87 ± 31,76). Esta superou os limites aceitáveis de variação do Clinical and Laboratory Standards Institute em 23,7 por cento dos casos, sendo maior que a glicA-lab em 90 por cento das vezes. A glicA-fita teve a melhor correlação (r = 0,9406), com concordância de -6,75 ± 19,07 e variação significativa em 7,9 por cento. Para a glicV-lab, obteve-se r = 0,8549, concordância de -4,20 ± 28,37 e variação significativa em 15,7 por cento. Variação significativa foi mais frequente em pacientes com noradrenalina (36,4 por cento versus 6,3 por cento, P = 0,03), mas não nos com hipoperfusão. Houve discordância de conduta clínica em 25 por cento, 22,5 por cento e 15 por cento dos casos para glicC-fita, glicV-lab e glicA-fita, respectivamente. CONCLUSÃO: O uso de glicC-fita deveria ser evitado, principalmente se há uso de noradrenalina. Geralmente, este método superestima a glicemia real e acarreta erros de conduta. Registro de ensaio clínico: ACTRN12608000513314 (registrado como estudo observacional transversal).

The impact of duration of organ dysfunction on the outcome of patients with severe sepsis and septic shock

OBJECTIVES: This study aimed to assess the impact of the duration of organ dysfunction on the outcome of patients with severe sepsis or septic shock. METHODS: Clinical data were collected from hospital charts of patients with severe sepsis and septic shock admitted to a mixed intensive care unit from November 2003 to February 2004. The duration of organ dysfunction prior to diagnosis was correlated with mortality. Results were considered significant if p<0.05. RESULTS: Fifty-six patients were enrolled. Mean age was 55.6 ± 20.7 years, mean APACHE II score was 20.6 ± 6.9, and mean SOFA score was 7.9 ± 3.7. Thirty-six patients (64.3 percent) had septic shock. The mean duration of organ dysfunction was 1.9 ± 1.9 days. Within the univariate analysis, the variables correlated with hospital mortality were: age (p=0.015), APACHE II (p=0.008), onset outside the intensive care unit (p=0.05), blood glucose control (p=0.05) and duration of organ dysfunction (p=0.0004). In the multivariate analysis, only a duration of organ dysfunction persisting longer than 48 hours correlated with mortality (p=0.004, OR: 8.73 (2.37-32.14)), whereas the APACHE II score remained only a slightly significant factor (p=0.049, OR: 1.11 (1.00-1.23)). Patients who received therapeutic interventions within the first 48 hours after the onset of organ dysfunction exhibited lower mortality (32.1 percent vs. 82.1 percent, p=0.0001). CONCLUSIONS: These findings suggest that the diagnosis of organ dysfunction is not being made in a timely manner. The time elapsed between the onset of organ dysfunction and initiation of therapeutic intervention can be quite long, and this represents an important determinant of survival in cases of severe sepsis and septic shock.