Sonographic Caval/Aorta Diameter And Inferior Vena Cava Collapsibility Indices For Assessment Of Preoperative Intravascular Volume Status In Elective Surgery Patients

Abstract

Introduction: The assessment of preoperative intravascular volume status is crucial for optimizing fluid management in patients undergoing elective surgery. Inaccurate volume status estimation can lead to complications related to hypovolemia or fluid overload. Traditional methods like central venous pressure monitoring are invasive and may not be readily available or accurate. The advances in non-invasive sonographic techniques offer an alternative approach. Two indices, the Caval/aorta diameter index (IVC/Ao) and inferior venacava collapsibility index (IVCCI), have shown a promise in evaluating intravascular volume status.

Methods: This observational study included adult patients undergoing elective non-cardiac surgery. Ultrasonographic measurement of the IVC maximum and minimum diameter and aortic diameter were obtained before the  induction of anesthesia. The IVCCI and IVC/Ao index were then calculated. IVCCI of >50% and Caval/Ao index of <1.0 was considered as hypovoalemic state.

Results: Hundred and twenty-six patients were analyzed from whom the means of maximum IVC diameter, abdominal aorta diameter, IVC/Ao index, and IVCCI were 1.686 ± 0.44 cm, 1.41±0.32 cm, 1.2±0.33, and 42.98 ±7.2 respectively (mean±S.D.). Of the 126 patients, 27.77% of the patient had IVC/Ao index of <1.0, and 17.46% had IVCCI of >50%.

Conclusion: Using sonographic IVC/Ao and IVCCI indices appears to be easy, quick, reliable and non-invasive way to determine the fluid status of the patients who have fasted before surgery. These indices show a promising technique for identifying hypovolemia in early stages, which should be investigated further in the near future.