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Objective To synthesize the evidence about diagnostic accuracy of inferior vena cava collapsibility (IVCc) in prediction of fluid responsiveness among spontaneously breathing patients. Design Systematic review of diagnostic accuracy studies. Setting Intensive care units or emergency departments. Patients and participants spontaneously breathing patients with indication for fluid bolus administration. Interventions A search was conducted in MEDLINE and EMBASE. We included studies assessing IVCc accuracy for fluid responsiveness assessment with a standard method for cardiac output measure as index test. Main variables of interest General information (year, setting, cutoffs, standard method), sensitivity, specificity, and area under the receiving operator characteristics curve (AUROC). Risk of bias was assessed with QUADAS 2 tool. We obtained the pooled sensitivity, specificity and summary ROC curve, with estimated confidence intervals from a bivariate model. We also calculated positive and negative likelihood ratios and developed a Fagon nomogram. Result Eight studies were included with 497 patients. Overall, the studies presented a high risk of bias. IVCc sensitivity was 63% (95% CI – 46–78%) and specificity 83% (95% CI – 76–87%). Despite moderate accuracy of IVCc (SROC 0.83, 95% CI – 0.80–0.86), post-test probability of being fluid responsive based on a 50% pre-test probability led to considerable misclassification. Conclusions IVCc had moderate accuracy for fluid responsiveness assessment in spontaneously breathing patients and should not be used in isolation for this purpose (AU)

Objetivo Sintetizar la evidencia sobre la precisión diagnóstica de la colapsabilidad de la vena cava inferior (cVCI) en la predicción de la respuesta a los líquidos en pacientes que respiran espontáneamente. Diseño Revisión sistemática de estudios de precisión diagnóstica. Ámbito Unidades de cuidados intensivos o servicios de urgencias. Pacientes o participantes Pacientes con respiración espontánea con indicación de administración de bolos de líquidos. Intervenciones Se realizó una búsqueda en MEDLINE y EMBASE. Se incluyeron los estudios que evaluaban la precisión de la cVCI con un método estándar para medir el gasto cardíaco como prueba índice. Variables de interés principales Información general (año, entorno, puntos de corte, método estándar), sensibilidad, especificidad y área bajo curva. El riesgo de sesgo se evaluó con la herramienta QUADAS2. Obtuvimos la sensibilidad combinada, la especificidad y la curva ROC resumida, con intervalos de confianza (IC) estimados a partir de un modelo bivariado. Resultados Se incluyeron 8 estudios con 497 pacientes. La sensibilidad de la cVCI fue del 63% (IC95%: 46-78%) y la especificidad del 83% (IC95%: 76-87%). A pesar de la precisión moderada de cVCI (SROC: 0,83; IC95%: 0,80-0,86), la probabilidad posterior a la prueba de responder a los fluidos basada en una probabilidad anterior al 50% dio lugar a una clasificación errónea considerable. Conclusiones La cVCI tuvo una exactitud moderada para la evaluación de la respuesta a los líquidos en pacientes que respiran espontáneamente y no debe usarse de forma aislada para este propósito (AU)

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RESUMEN

OBJECTIVE: To synthesize the evidence about diagnostic accuracy of inferior vena cava collapsibility (IVCc) in prediction of fluid responsiveness among spontaneously breathing patients. DESIGN: Systematic review of diagnostic accuracy studies. SETTING: Intensive care units or emergency departments. PATIENTS AND PARTICIPANTS: spontaneously breathing patients with indication for fluid bolus administration. INTERVENTIONS: A search was conducted in MEDLINE and EMBASE. We included studies assessing IVCc accuracy for fluid responsiveness assessment with a standard method for cardiac output measure as index test. MAIN VARIABLES OF INTEREST: General information (year, setting, cutoffs, standard method), sensitivity, specificity, and area under the receiving operator characteristics curve (AUROC). Risk of bias was assessed with QUADAS 2 tool. We obtained the pooled sensitivity, specificity and summary ROC curve, with estimated confidence intervals from a bivariate model. We also calculated positive and negative likelihood ratios and developed a Fagon nomogram. RESULTS: Eight studies were included with 497 patients. Overall, the studies presented a high risk of bias. IVCc sensitivity was 63% (95% CI - 46-78%) and specificity 83% (95% CI - 76-87%). Despite moderate accuracy of IVCc (SROC 0.83, 95% CI - 0.80-0.86), post-test probability of being fluid responsive based on a 50% pre-test probability led to considerable misclassification. CONCLUSIONS: IVCc had moderate accuracy for fluid responsiveness assessment in spontaneously breathing patients and should not be used in isolation for this purpose.

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Este estudo teve como objetivo avaliar o efeito de diferentes intervalos entre pastejos sobre as características produtivas de trevo-persa e azevém, consorciados e manejados sob lotação rotacionada, nos anos de 2009 e 2010. Os tratamentos consistiram em quatro intervalos entre pastejos (tempo para o surgimento de 2,5; 3,5; 4,5 e 5,5 folhas em plantas de trevo-persa), em delineamento de blocos completos ao acaso, com seis repetições. As variáveis analisadas foram: índice de área foliar, área foliar, altura do pasto e de plantas, comprimento de perfilhos/ramificações, taxa de acúmulo de matéria seca e produção de matéria seca. O índice de área foliar do dossel e do trevo-persa foi maior no intervalo de 5,5 folhas nos anos de 2009 e 2010. No ano de 2009, maiores valores de área foliar foram obtidos nos intervalos de 3,5 e 4,5 folhas e não se observou efeito dos intervalos entre pastejos sobre essa variável em 2010. Maiores intervalos entre pastejos proporcionaram maior altura do pasto e de plantas e também maior comprimento de perfilhos e ramificações. A produção de matéria seca do trevo-persa foi maior em 2010, ao passo que, para azevém, maior produção foi encontrada em 2009. A produção de matéria seca total foi maior no intervalo de 5,5 folhas. A taxa de acúmulo de matéria seca foi maior no intervalo de 5,5 folhas em 2009 e no intervalo de 2,5 folhas em 2010. As características produtivas da consorciação trevo-persa e azevém anual são modificadas pelos intervalos entre pastejos. Recomendam-se intervalos de até 3,5 folhas surgidas, em consorciação de trevo-persa e azevém anual, os quais proporcionam menor alongamento de caules associado à menor presença de material morto, o que, provavelmente, melhora a qualidade da forragem colhida.

The aim of this trial was to study the effect of different grazing intervals on productive characteristics of persian clover and ryegrass, in consortium and managed under rotational stocking during the years 2009 and 2010. Treatments were composed of four grazing intervals (time to onset of 2.5; 3.5; 4.5 and 5.5 leaves in persian clover plants) allocated in completely randomized blocks, with six replications. Leaf area index (LAI), leaf area, pasture and plants height, length of tillers/branches, rate of dry matter accumulation and dry matter yield were evaluated. The leaf area index of the canopy and the persian clover was higher in the interval of 5.5 leaves in years 2009 and 2010. In 2009, higher values of leaf area were obtained in intervals of 3.5 and 4.5 leaves and there no was effect of grazing intervals on this variable in 2010. Higher grazing intervals provided greater pasture height and plant height and also greater tiller and branch length. The dry matter production of persian clover was higher in 2010, while for ryegrass highest yields were found in 2009. Total dry matter yield was higher in the interval of 5.5 leaves. The rate of dry matter accumulation was higher in the interval of 5.5 leaves in 2009 and in the interval of 2.5 leaves in 2010. The productive characteristics of a of mixture persian clover and ryegrass are modified by the grazing intervals. It is recommended intervals up to 3.5 of appeared leaves with a mixture of persian clover and ryegrass, which provides lower elongation of stems associated with a lower presence of dead material, which probably improves the quality of the harvested forage.

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