Vascular content, tone, integrity, and haemodynamics for guiding fluid therapy: a conceptual approach

Despite many clinical trials and investigative efforts to determine appropriate therapeutic intervention(s) for shock, this topic remains controversial. The use of i.v. fluid has represented the cornerstone for the treatment of hypoperfusion for two centuries.

As a part of International Acute Dialysis Quality Initiative XII Fluids Workgroup meeting, we sought to incorporate recent advances in our understanding of vascular biology into a more comprehensive yet accessible approach to the patient with hypoperfusion. In this workgroup, we attempted to develop a framework that incorporates key aspects of the vasculature into a diagnostic approach.

The four main components of our proposal involve the assessment of the blood flow (BF), vascular content (vC), the vascular barrier (vB), and vascular tone (vT). Any significant perturbation in any of these domains can lead to hypoperfusion at both the macro- and micro-circulatory level. We have termed the BF, vC, vB, and vT diagnostic approach the vascular component (VC) approach.

The VC approach to hypoperfusion has potential advantages to the current diagnostic system. This approach also has the distinct advantage that it can be used to assess the systemic, regional, and micro-vasculature, thereby harmonizing the approach to clinical vascular diagnostics across these levels. The VC approach will need to be tested prospectively to determine if this system can in fact improve outcomes in patients who suffer from hypoperfusion.