A prospective, observational study of non-invasive venous waveform analysis (NIVA) for the detection of acute low volume blood loss in humans

Abstract

Background

Accurate non-invasive monitoring for the diagnosis of hemorrhage is an unmet need in acute care settings. Non-Invasive Venous waveform Analysis (NIVA) has demonstrated significant sensitivity in detecting acute hemorrhage with 8–10 % blood volume loss. To determine whether NIVA can accurately and non-invasively detect lower volumes of blood loss, we performed a prospective observational study using a digital blood volume monitor at an American Red Cross (ARC) donation center to assess NIVA's performance at lower blood volume loss.

Methods

Venous waveforms were successfully captured in 33 ARC-approved patients. Waveforms were recorded for the duration of whole blood donation and then transformed from the time domain to the frequency domain. The ratiometric power contribution of the cardiac frequencies was used to calculate a representative volume status value, the IntraVAscular Number (IVAN).

Results

A significant decrease in the IVAN output was observed after just 200 mL (3–4 % blood volume) of whole blood donation (p < 0.05). The ROC curve demonstrated an Area Under the Curve (AUC) of 0.65 for the ability of delta IVAN to detect 200 mL of blood loss. The Receiver Operating Characteristic (ROC) curve demonstrated an AUC of 0.91 for the ability of delta IVAN to detect 500 mL of blood loss.

Conclusion

There remains a large unmet need for accurate and timely detection of acute hemorrhage. This study supports the potential application of NIVA in the detection of acute low-volume human blood loss. NIVA is a novel technology that uses previously undetectable low-amplitude venous signals of the cardiac pulse, which may prove useful for more accurate and early detection of acute hemorrhage.