Autologous blood resuscitation for large animals in a research setting using the Hemafuse device: Preliminary data of device use for controlled and real-world hemorrhage

Abstract

Introduction: New low-cost technologies are needed to salvage lost blood in low-resource settings and large animal laboratories. The Hemafuse device is a simple mechanical device that can recover lost blood during surgery. The aim of this study is to assess the feasibility of this device for resuscitating large animals with controlled and unintended hemorrhage and to provide device considerations for use in this context.

Methods: This study had two experimental components: (1) the Hemafuse device was kept on-shelf and used as needed to assess real-world use for unintended hemorrhage during experiments, and (2) animals underwent a controlled hemorrhage protocol, where four anesthetized swine underwent aortic and external jugular vein catheterization for pressure monitoring. Animals were hemorrhaged into the pelvis, and the Hemafuse device was used to suction the blood through a filter and pushed into a heparinized bag for subsequent retransfusion. Blood samples were collected at baseline, hemorrhage, within the device, and post-retransfusion and laboratory tests were performed.

Results: Animals that underwent controlled hemorrhage had a baseline mean arterial pressure of 83.6 ± 7.8 mmHg, and central venous pressure of 12.8 ± 1.9 mmHg, with expected changes throughout hemorrhage and resuscitation. Following resuscitation, pH was similar to baseline (7.39 ± 0.05 vs. 7.31 ± 0.03, p = 0.24). Lactate increased throughout the experiment with no significant differences after autotransfusion compared to baseline (2.7 ± 0.7 vs. 4.1 ± 1.4 mmol/L, p = 0.37). There were no significant changes in metabolic physiology. Compared to baseline, the hemoglobin (7.8 ± 2.4 vs. 7.3 ± 1.8 g/dL, p = 0.74), hematocrit (23% ± 6.9 vs. 21.3% ± 5.6, p = 0.71), and activated clotting time (268.5 ± 44.5 vs. 193 ± 24.6 s, p = 0.35) were similar after retransfusion. When used for unintended hemorrhage, the animals were resuscitated using the device with a mean time to retransfusion time of 128.7 ± 13.3 s and 100% survival throughout the experiment.

Conclusion: The Hemafuse device is feasible and efficacious for supporting large animal resuscitation. This is preliminary evidence that the device is a low-risk and low-cost off-the-shelf option for resuscitation using autologous blood with no significant effect on physiology post-retransfusion. We recommend that research laboratories consider the Hemafuse device for emergency use, particularly for highly invasive surgical laboratories where banked blood is not readily available.

Keywords: Hemafuse; autologous blood; blood bank; hemorrhage; large animals; resuscitation; whole blood.

Figure 1

Illustration of the Hemafuse device and the individual parts courtesy of the Sisu Global (https://sisuglobal.health/brochures). Beneath the illustration is a step-by-step procedure on how to use the device: (1) Pull the handle to suction blood into the barrel, (2) ensure the outlet port up, and open the stopcock, (3) push the handle to release air out of the barrel, (4) rotate outlet port down, and close stopcock, and (5) push blood from the barrel into a heparinized blood bag.

Figure 2

Images of the device and pelvic exposure: (A) The Hemafuse device (barrel) and the suction cannula are connected to an empty blood bag (i.e., an empty crystalloid 1L bag), and (B) surgical exposure of the pelvic well created for the pelvic hemorrhage model.

Figure 3

Images of the pelvic hemorrhage model and device set-up: (A) The pelvic exposure with the femoral artery sheath actively hemorrhaging into the pelvic well and (B) the set-up of the Hemafuse device with the suction cannula in the pelvic well.

Figure 4

The hemodynamic variables across time: (A) Mean arterial pressure shown throughout baseline, hemorrhage, retransfusion of autologous blood, and a critical care period with intravenous fluid, if needed, and (B) central venous pressure shown throughout baseline, hemorrhage, and a similar resuscitation period.

Figure 5

The iliac artery blood flow of one animal over time, including baseline, hemorrhage, retransfusion of autologous blood, and a critical care period.

Figure 6

The metabolic laboratory tests were performed over time or between samples from the animal at baseline, within the device, and the animal at retransfusion: (A) Temperature of the animals across time. (B) pH at baseline, device, and retransfusion with significant differences between baseline vs. device and device vs. retransfusion but no difference between baseline vs retransfusion, and (C) lactate at baseline, device, and retransfusion without any significant differences. The central lines represent the means and the error bars represent the standard deviation. p < 0.05 is represented by *, a p < 0.001 is represented by **, and nonsignificant p values are presented by ns.

Figure 7

The hematologic laboratory tests were grouped into samples from the animal at baseline, within the device, and the animal at retransfusion: (A) Hemoglobin at baseline, device, and retransfusion without any significant differences. (B) hematocrit at baseline, device, and retransfusion without any significant differences, and (C) ACT at baseline, device, and retransfusion without any significant differences. The central lines represent the means and the error bars represent the standard deviation. Nonsignificant p-values are presented by ns.