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The caval index: an adequate non-invasive ultrasound parameter to predict fluid responsiveness in the emergency department?

de Valk S, Olgers TJ, Holman M, Ismael F, Ligtenberg JJ, Ter Maaten JC - BMC Anesthesiol (2014)

Bottom Line: An adequate response was defined as an increase in systolic blood pressure of at least 10 mm Hg.After selection a total number of 45 patients was included.The positive predictive value of a high caval index was much lower (48%) despite the fact that responders had a significantly higher pre-infusion caval index than non-responders (48.7% vs 31.8%, p 0.014).

View Article: PubMed Central - PubMed

Affiliation: Emergency Department, Department of Internal Medicine, University Medical Center Groningen, UMCG, Hanzeplein 1, 9700 RB Groningen, The Netherlands.

ABSTRACT

Background: Fluid therapy is the first important step in patients with signs of shock but assessment of the volume status is difficult and invasive measurements are not readily available in the emergency department. We have investigated whether the respiratory variation in diameter of the inferior vena cava is a reliable parameter to predict fluid responsiveness in spontaneous breathing emergency department patients with signs of shock.

Methods: All patients admitted to the emergency department during a 15 week period were screened for signs of shock. If the attending physician planned to give a fluid challenge, the caval index was determined by transabdominal ultrasonography in supine position. Immediately afterwards 500 ml NaCl 0.9% was administered in 15 minutes and the clinical response was observed. An adequate response was defined as an increase in systolic blood pressure of at least 10 mm Hg. Based on this definition patients were divided into responders and non-responders.

Results: After selection a total number of 45 patients was included. A low caval index (< 36.5%) in patients with signs of shock reliably predicted the absence of an adequate response to fluid therapy (negative predictive value 92%). The positive predictive value of a high caval index was much lower (48%) despite the fact that responders had a significantly higher pre-infusion caval index than non-responders (48.7% vs 31.8%, p 0.014).

Conclusions: In spontaneously breathing patients with signs of shock in the emergency department, a high caval index (>36.5%) does not reliably predict fluid responsiveness in our study, while a low caval index (<36.5%) makes fluid responsiveness unlikely. An explanation for the absence of a blood pressure response in the group of patients with a low high caval index might be that these patients represent a group requiring more volume therapy than 500 ml.

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Receiver operating characteristic (ROC) curve analysis of the caval index as predictor of fluid responsiveness. Area under the curve 0.741. Optimal threshold value is 36.5% with 83% sensitivity and 67% specificity.
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Fig2: Receiver operating characteristic (ROC) curve analysis of the caval index as predictor of fluid responsiveness. Area under the curve 0.741. Optimal threshold value is 36.5% with 83% sensitivity and 67% specificity.

Mentions: Figure 1 shows there is only a weak relationship between the pre-infusion caval index and the change in systolic blood pressure after a fluid challenge (r = 0.259, p = 0.086). A Receiver Operating Characteristic (ROC) curve shows in this study population an optimal threshold value for the caval index to predict fluid responsiveness of 36.5% (Figure 2). With this threshold value fluid responsiveness (defined as an increase in systolic blood pressure) is predicted with a sensitivity of 83% and a specificity of 67%.Figure 1


The caval index: an adequate non-invasive ultrasound parameter to predict fluid responsiveness in the emergency department?

de Valk S, Olgers TJ, Holman M, Ismael F, Ligtenberg JJ, Ter Maaten JC - BMC Anesthesiol (2014)

Receiver operating characteristic (ROC) curve analysis of the caval index as predictor of fluid responsiveness. Area under the curve 0.741. Optimal threshold value is 36.5% with 83% sensitivity and 67% specificity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4384238&req=5

Fig2: Receiver operating characteristic (ROC) curve analysis of the caval index as predictor of fluid responsiveness. Area under the curve 0.741. Optimal threshold value is 36.5% with 83% sensitivity and 67% specificity.
Mentions: Figure 1 shows there is only a weak relationship between the pre-infusion caval index and the change in systolic blood pressure after a fluid challenge (r = 0.259, p = 0.086). A Receiver Operating Characteristic (ROC) curve shows in this study population an optimal threshold value for the caval index to predict fluid responsiveness of 36.5% (Figure 2). With this threshold value fluid responsiveness (defined as an increase in systolic blood pressure) is predicted with a sensitivity of 83% and a specificity of 67%.Figure 1

Bottom Line: An adequate response was defined as an increase in systolic blood pressure of at least 10 mm Hg.After selection a total number of 45 patients was included.The positive predictive value of a high caval index was much lower (48%) despite the fact that responders had a significantly higher pre-infusion caval index than non-responders (48.7% vs 31.8%, p 0.014).

View Article: PubMed Central - PubMed

Affiliation: Emergency Department, Department of Internal Medicine, University Medical Center Groningen, UMCG, Hanzeplein 1, 9700 RB Groningen, The Netherlands.

ABSTRACT

Background: Fluid therapy is the first important step in patients with signs of shock but assessment of the volume status is difficult and invasive measurements are not readily available in the emergency department. We have investigated whether the respiratory variation in diameter of the inferior vena cava is a reliable parameter to predict fluid responsiveness in spontaneous breathing emergency department patients with signs of shock.

Methods: All patients admitted to the emergency department during a 15 week period were screened for signs of shock. If the attending physician planned to give a fluid challenge, the caval index was determined by transabdominal ultrasonography in supine position. Immediately afterwards 500 ml NaCl 0.9% was administered in 15 minutes and the clinical response was observed. An adequate response was defined as an increase in systolic blood pressure of at least 10 mm Hg. Based on this definition patients were divided into responders and non-responders.

Results: After selection a total number of 45 patients was included. A low caval index (< 36.5%) in patients with signs of shock reliably predicted the absence of an adequate response to fluid therapy (negative predictive value 92%). The positive predictive value of a high caval index was much lower (48%) despite the fact that responders had a significantly higher pre-infusion caval index than non-responders (48.7% vs 31.8%, p 0.014).

Conclusions: In spontaneously breathing patients with signs of shock in the emergency department, a high caval index (>36.5%) does not reliably predict fluid responsiveness in our study, while a low caval index (<36.5%) makes fluid responsiveness unlikely. An explanation for the absence of a blood pressure response in the group of patients with a low high caval index might be that these patients represent a group requiring more volume therapy than 500 ml.

Show MeSH
Related in: MedlinePlus