Qualitative Assessment of the Inferior Vena Cava: Useful Tool for the Evaluation of Fluid Status in Critically Ill Patients

Abstract

Inferior vena cava (IVC) diameter change on limited transthoracic echocardiogram (LTTE) can provide a useful guide of fluid status evaluation in critically ill patients. Institutional review board approval was obtained. Prospective evaluation of hemodynamic status was performed in hypotensive patients via LTTE. Images were obtained using an ultrasound machine without M-mode capability. Qualitative assessment of the IVC was obtained via subxyphoid window. FLAT IVC was defined as diameter less than 2 cm and FAT IVC when the vein was equal or larger than 2 cm. Collapsibility was assessed by observing respiratory variation of the vessel. Lactate was measured before and after therapy was initiated. A follow-up LTTE was obtained after fluid challenge. A total of 108 LTTE were performed. Patients’ age ranged from 18 to 89 years with an average of 53. Admission diagnosis was blunt trauma in 66 patients, penetrating trauma in 17, whereas 25 had nontraumatic intra-abdominal emergency. Sixty-nine patients were receiving mechanical ventilation at time of LTTE. Seventy-three patients had a FLAT IVC, and received fluid challenge as therapy. All patients had a change in IVC volume from “FLAT” to “FAT” after the fluid challenge. Seventy-one patients (97%) had resolution of hypotension after the first fluid challenge. Two patients had persistent hypotension and received a second fluid challenge. Follow-up LTTE demonstrated a FAT IVC and lack of collapsibility. Lactate decreased in all 73 patients after therapy guided by LTTE ( P < 0.00001) Evaluation of the IVC diameter via LTTE offers a rapid, non invasive way to evaluate fluid status in critically ill patients.

Changes in Sonographically Measured Inferior Vena Caval Diameter in Response to Fluid Loading in Term Pregnancy

“…For this reason, the collapsibility index (reflecting the degree of vessel collapse during intrathoracic pressure changes of the respiratory cycle) is a useful measure for estimating cardiac preload. A collapsibility index of greater than 50% in nonpregnant patients along with a decreased IVC diameter of less than 2.1 cm suggests hypovolemia 7 . In our study, the collapsibility index ranged from 14% to 18% and did not change significantly with volume infusion, suggesting that central venous pressure was maintained across the spectrum of volume changes we evaluated.…”

Index aus Diameter der Vena cava inferior und Aorta abdominalis bei Neugeborenen – eine praxisrelevante Methode zur Erfassung einer Hypovolämie

“…Ähnliche Ergebnisse werden von Chen et al und Modi dargestellt, die eine signifikante Korrelation von Index IVC/ Ao zum Grad des Wasserverlustes bei Säuglingen aufzeigen konnten [23,24]. Ebenso wird für Erwachsene das genannte sonografische Verfahren durch eine größere Anzahl von Arbeitsgruppen als relevante Methode zu Beurteilung der Volumensituation beschrieben [9,16,25,26,27]. Keine der zitierten Arbeiten bezieht jedoch Neugeborene in die Untersuchungen ein.…”

Diameter and collapse index of inferior vena cava as a clinical indicator of resuscitation for critically ill hypotensive patients

“…4,8,9,10 The qualitative assessment of DCIIVC has also been carried out in a prospective study and demonstrated that DCIIVC offers a rapid, non-invasive way to evaluate VS in critically ill patients. 11 Despite its accuracy and usefulness, DCIIVC is not widely used as a clinical indicator for FR.…”