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“I have operated The Belmont® through hundreds of bags of blood. Many injuries here in Afghanistan are very traumatic, because of the enemies’ use of the IED (improvised explosive device), injuries such as multiple amputations of extremities, blast injuries, gunshot wounds, and others. Your pump has given me witness to bringing multiple GI’s back to life, because of the rapid administration of blood products your pump provides.” -United States Navy Reserve LCDR NC

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Gopinath, Anupama MBChB, MRes; Nelson, Chaim MD; Gupta, Anupriya MD; Bonney, Iwona PhD; Schumann, Roman MD

doi: 10.1213/ANE.0000000000001183

Cardiovascular Anesthesiology: Research Report

Electromagnetic coil overheating, deformation, occlusion, and rupture during rapid infuser use have been previously reported. Although the etiology is unclear, prolonged machine use and reconstitution of citrated blood components with crystalloid solutions in the reservoir have been implicated. Lactated Ringer's (LR) solution is of particular concern as a diluent because of its calcium content. We sought to reproduce this failure mode using different infusion rates and different combinations of fluids for blood product reconstitution in the reservoir. We also introduced calcium chloride (CaCl ₂) to the mix to determine its role in macroscopic clot formation.

In this in vitro study, we conducted 2 series of experiments using the Belmont FMS 2000 rapid infuser and a reservoir. In series I, we submitted a mix of 1 U fresh thawed plasma (FTP) and 1 U red blood cells (RBC) with 500 mL of LR solution, normal saline, Plasma-Lyte A, or albumin 5% to a specific pump flow sequence. If neither a pump failure mode or self-shutoff (primary outcome) nor macroscopic clot (secondary outcome) was observed during a pump flow sequence, the sequences were repeated after first adding an additional 500 mL of the initially used crystalloid or albumin and then CaCl ₂ beginning with 200 mg and up to 1 g to the reservoir. In series II, 7 different crystalloid-blood product combinations were tested by using a variety of pump flow sequences with the same end points. Descriptive statistics and analysis of variance were used, and data were reported as means ± SD.

We did not observe a Belmont pump failure mode (coil deformation, occlusion, or rupture) as previously described. In series I, the addition of CaCl ₂ 200 mg resulted in macroscopic clots in 9 of 10 experiments (95% confidence interval, 0.55-0.99). The time to clot formation was 9.1 ± 2.3 minutes (99% confidence interval, 6.74-11.46) and did not differ between solutions used for component reconstitution. In series II, adding variable amounts of CaCl ₂ to 4 different combinations of FTP/RBC with Plasma-Lyte A or LR solution led to clot formation. The use of only FTP in 2 experiments with either LR solution or normal saline resulted in formation of a fibrin clot. In 1 experiment of LR solution mixed with RBCs alone, no clot was observed even after addition of 1 g CaCl ₂. After the observation of clot in the reservoir, the fluid empty alarm occurred once in series I, the overheating alarm occurred once in series II, and the high-pressure alarms occurred 3 times in each series, all accompanied by self-shutoff.

In this in vitro study, we were unable to reproduce the failure mode characterized by coil overheating, deformation, and rupture previously reported with use of the FMS 2000. Addition of CaCl ₂ in the range of 200 mg caused macroscopic coagulation in the reservoir when added to crystalloids or albumin mixed with different combinations of blood products containing FTP.

Supplemental Digital Content is available in the text.

From the Department of Anesthesiology, Tufts Medical Center, Boston, Massachusetts.

Accepted for publication December 18, 2015.

Funding: Department of Anesthesiology, Tufts Medical Center. Disposables for the study were provided by the Belmont Instrument Corporation, Billerica, MA. Blood products were provided by the Blood Bank of Tufts Medical Center.

The authors declare no conflicts of interest.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website.

Drs. Gopinath and Nelson have contributed equally to this work and should be considered co-first authors.

Reprints will not be available from the authors.

Address correspondence to Roman Schumann, MD, Department of Anesthesiology, Tufts Medical Center, 800 Washington St., Box# 298, Boston, MA 02111. Address e-mail to RSchumann@tuftsmedicalcenter.org.

A variety of rapid volume infusers are available to assist in the resuscitation of trauma patients or in cases with the potential for sudden, life-threatening hemorrhage. Massive transfusion often relies on the use of such infusers, which are designed to safely deliver warmed fluids and blood products across a wide range of flow rates. These devices use different mechanisms for pumping and warming fluid, including pressure chambers or roller pumps, and countercurrent heating systems or electromagnetic induction heating coils. The Belmont FMS 2000 rapid infuser (Belmont Instrument Corporation, Billerica, MA) uses a roller pump and heating coil arrangement and offers the use of a reservoir for high-volume infusion. Because these infusion devices have a pumping function, blood products need not be diluted with crystalloid to facilitate flow. However, in clinical practice, the reservoir and pump may be loaded and primed with a combination of crystalloid and blood products.

After a case report of coil overheating and deformation by Husser et al.,1 a more recent case series by Xia et al.2 described the use of the Belmont FMS 2000 system during liver transplantation where overheating to >42°C and blood clot occlusion of the electromagnetic heating coil with subsequent inability to administer fluids were observed. The authors hypothesized that blood clot formation led to heating coil occlusion, stasis, and subsequent overheating. Among 12 overheated units used by Xia et al.,2 calcium was found in the 2 that were sent off-site for analysis. However, the authors reported no use of calcium or calcium-containing solutions and, in a separate account, described 23 additional cases of overheating.3 In 1 instance, calcium was detected exclusively downstream from the heating coil and none in the reservoir or upstream.3 The role of calcium in pump failure events is thus unclear.

We hypothesized that 1 potential mechanism for coil occlusion, overheating, and damage may be the interaction of calcium-containing crystalloids with reconstituted citrated blood products in the reservoir. We further hypothesized that variability in pump speeds during prolonged periods of use could also contribute to or trigger pump occlusion.

Therefore, the purposes of this study were as follows:

1. To reproduce the Belmont FMS 2000 pump failure mode previously reported using different combinations of crystalloids and blood products in the reservoir and applying escalating pump flow rates in a closed-loop model.

2. To evaluate the effect of different crystalloid types, albumin, and calcium chloride (CaCl₂) addition on the incidence of macroscopic clot formation and pump failure.

METHODS

Blood Products and Fluids

We used fresh thawed plasma (FTP) and red blood cells (RBC) that either recently expired or had experienced a storage violation prohibiting further clinical use. These blood products were donated to the study by the institutional blood bank, and donated FTP and RBC were kept at 4°C until start of the study. Both FTP and RBC were derived from donated whole-blood units anticoagulated with calcium-phosphate-dextrose. RBC anticoagulation also included calcium-phosphate-dextrose adenine-1 for cell preservation.

The specific crystalloids tested (Baxter Healthcare Corporation, Deerfield, IL) were lactated Ringer's (LR) solution, 0.9% normal saline (NS) solution, and Plasma-Lyte A (PL) solution. In addition, we also tested 5% human albumin solution (Alb; Grifols Biologicals Inc., Los Angeles, CA). All crystalloids and albumin used were stored at room temperature until use.

Study Protocol

We conducted an IRB-approved, observational in vitro study using the Belmont FMS 2000 with a reservoir. During the experiments, a closed circuit was created by connecting the pump output line to the reservoir input inside the filtration chamber ( Fig. 1). We conducted 2 separate series of experiments, series I and series II. Except for 1 experiment in series II where 4 units of blood product were used, all other experiments were performed with a maximum of only 2 units of blood product because of the limited and sporadic supply of compatible components.

In series I, a combination of 1 unit FTP and 1 unit RBC with 500 mL of 1 of 3 different crystalloid solutions or albumin were mixed into the reservoir and then cycled through the infusion device and back into the reservoir (Fig. 1). This closed-loop system allowed the mix in the reservoir to be constantly agitated as it would be in clinical practice during high-volume replacement, yet it provided for a constant, controlled crystalloid/blood component composition during each pump flow sequence. Each mixture was then submitted to a flow sequence (A-D) and a stepwise addition of CaCl ₂ to the reservoir as shown in Figure 2. The experiment was performed twice for each fluid and blood product combination. LR solution was tested for an additional 2 times for a total of 10 series I experiments.

We hypothesized that the addition of calcium to blood products containing clotting factors such as FTP may contribute to inadvertent coagulation. Because 1 L LR solution contains approximately 200 mg CaCl ₂, in series I (Fig. 2), we added CaCl ₂ at an initial dose of 200 mg to the reservoir if no pump failure or coagulation occurred after sequences A and B.

In series II, we conducted 7 additional experiments with different fluid and blood component combinations based on product availability ( Table 1). In each experiment, a specific combination of diluent (crystalloid or albumin), packed RBC, and FTP was subjected either to the flow sequence as in Figure 2 or a different flow sequence and the addition of variable amounts of CaCl ₂ (Supplemental Digital Content, http://links.lww.com/AA/B363).

All experiments ended when either an end point was reached or a maximal amount of 1 g CaCl ₂ was added.

A dedicated observer checked the pump for the previously described failure mode or any pump alarm and self-shutoff (primary outcome) and the reservoir for the development of macroscopic clot (secondary outcome). We defined pump failure as coil occlusion, deformation, and rupture or any instance during which the pump would stop operating because of its safety mechanisms and alarm, including overheating and high line pressure. When a clot was observed in the reservoir without first triggering a pump stop, the pump flow and machine behavior were assessed for up to an additional 5 minutes of operation. The flow rate, stage of the experiment at the time of reaching a study end point, and any subsequent pump stop and alarm message were recorded. The heating coil of the pump insert was visually inspected and digitally photographed.

We used Stata/IC 13.1 (StataCorp, College Station, TX) for the 1-way analysis of variance method to compare the time to clot observation among the different fluid and blood product combinations, and the Clopper-Pearson test to determine the 95% confidence interval (CI) for the point estimate of clot observation in series I. We assumed a non-normal distribution to calculate the 99% CI for the time to clot formation in series I. Because of the lack of homogeneity with respect to variables that might influence the presence of an alarm in each of the 2 series, 99% CIs were calculated for these point estimates to be more conservative.

A P value <0.05 was considered statistically significant. Data were reported as means ± SD.

RESULTS

A failure mode characterized by overheating, deformation, and rupture of the electromagnetic heating coil in the Belmont FMS 2000 rapid infuser could not be reproduced in our study.

In series I, no clot was observed in any experiment in sequences A and B. The addition of 200 mg CaCl ₂ to 1 L of PL solution, NS, LR solution, or albumin in sequence C produced the secondary study end point of macroscopic clot in the reservoir in 9 of the 10 experiments (95% CI, 0.55-0.99) ( Figs. 2 and 3). The mean time to clot formation after the most recent addition of CaCl ₂ in series I experiments was 9.1 ± 2.3 minutes (99% CI, 6.74-11.46). The time to clot formation did not differ with fluid type ( P = 0.56).

Of the 7 experiments in series II, we performed 5 experiments with LR solution, 1 experiment with NS, and 1 with PL solution by using different blood product combinations ( Table 1; Supplemental Digital Content, http://links.lww.com/AA/B363). We observed no evidence of coagulation in the single experiment of LR solution mixed with RBC alone, even when we added an additional 1 g CaCl ₂. However, when we mixed LR solution or NS with FTP only and added 200 mg CaCl ₂, we detected a fibrin clot that subsequently passed into the patient delivery line beyond the heating coil ( Fig. 4). In both instances, either the high-pressure or the overheating alarm triggered. In 1 series II experiment after adding calcium to PL solution, RBC, and FTP, a clot was also found in the patient delivery line.

Pump alarms and self-shutoff were noted only after a clot was observed in the reservoir when the infuser was allowed to keep running as follows: the pump safety stop engaged in 3 of 10 in series I and 3 of 7 in series II experiments because of a high-pressure alarm (99% CI, 0.037-0.735 and 99% CI, 0.055-0.882, respectively). The fluid empty alarm and the overheating alarm occurred once in series I and II, respectively (99% CI, 0.0005-0.544 and 99% CI, 0.007-0.684, respectively; Table 2). We did not observe any differences in appearance or clotting between the left and the right side of the heating coil as previously reported.2 Instead, we noted irregular, island-shaped markings on the metallic surface inside the heating coil at the end of the experiments that differed little between each test ( Fig.5).

We did not observe clot formation when combining LR solution, FTP, and RBC in any series I or II study without adding CaCl ₂.

The postexpiration ages in days for RBC and FTP were 8.5 ± 13.3 and 13.9 ± 14.2 (mean ± SD) in series I and 14.3 ± 19.7 and 7.4 ± 5.8 in series II.

DISCUSSION

Rapid infusion devices are commonly used in clinical practice, and device failure can adversely affect patient care. Assuming that a properly functioning device is appropriately handled by the clinician, the true incidence of device failure is unknown. The Food and Drug Administration provides the Manufacturer and User Facility Device Experience database that contains mandated and voluntary device reports including from manufacturers, device user facilities, health care professionals, and consumers.a We performed a simple search with the terms Belmont Instrument Corporation, FMS 2000, and Belmont rapid infuser. Examination of the results revealed 44 distinct reports between 2004 and the last update of the database at the time of this writing, August 2015. The reports involved 18 instances of the overheating alarm, 4 instances of heating element deformation, and 2 high-pressure alarms during this 11-year period. Information regarding reservoir use or content was insufficient to gain any insights into patterns of causation, and the number of unreported events remains uncertain. According to the manufacturer, almost 4000 Belmont FMS 2000 rapid infuser devices have been purchased worldwide and 60,000 of its disposables have been sold in 2014 (data supplied by Belmont Instrument Corporation).

In clinical practice, RBCs and other blood components may be reconstituted with crystalloids to improve flow and to prime rapid infuser reservoirs. Although studies have examined the coagulation potential of crystalloids with RBCs and FTP separately, there is very little information about crystalloid with RBC/FTP combinations regarding potential clot formation. In this in vitro study, combining FTP and RBCs with different types of crystalloid or albumin in the Belmont FMS 2000 rapid infuser with a reservoir, we were unable to re-create the warming unit overheating with coil deformation and rupture event reported by others.1,2 However, 1 overheating, 1 fluid empty, and several high-pressure alarms were triggered when we allowed continuing pump operation for 5 minutes after the observation of a macroscopic clot in the reservoir (a study end point).

Despite the dilution of 1 unit each of FTP and RBC with 1 L of NS, PL solution, LR solution, and albumin 5%, respectively, we consistently observed macroscopic clot formation in the reservoir after the addition of 200 mg CaCl ₂. Spontaneous clotting did not occur during our trial. Xia et al.2 also observed immediate clot formation in the reservoir and safety stop of the pump when they added 300 mg CaCl ₂ to 500 mL LR solution mixed with 2 units each of RBCs and FTP in 1 experiment.

Series II experiments demonstrated clot formation when 200 mg CaCl ₂ was added to 1 L LR solution or NS mixed with 2 U FTP. No coagulation occurred in the experiment where 1 L LR solution was combined with 2 U RBCs despite the addition of up to CaCl ₂ 1 g. The latter observation suggests that only a very small amount of clotting factors remain in currently available RBC units. Our results indicate that in the presence of coagulation factors (i.e., FTP), ≤200 mg CaCl ₂ may trigger macroscopic clot formation even when blood products are diluted to a 0.7:1 ratio.

The deliberate addition of CaCl ₂ to a blood component mix in a reservoir is unlikely to occur in clinical practice. It is conceivable that calcium may be added downstream from the reservoir into the patient line. However, this clinical use is unlikely to trigger a clot because the combination is rapidly flushed into the bloodstream.

At no time did coagulation occur immediately or with CaCl ₂ addition, but with a delay during the pump flow sequence. In our series I experiments, the time to coagulation when the fluid mixture was warmed and agitated by transit through the closed-loop system was 9.1 ± 2.3 minutes, suggesting that CaCl ₂-induced coagulation is a time-dependent process. With a clotting time of 9 minutes, it is possible that low pump flow rates used in clinical practice may provide adequate time for clotting to occur. Although the postexpiration age of the blood components had a range from 0 to 48 days, we found no effect of the type of fluid on the time to coagulation. After clot appearance in the reservoir, the high-pressure alarm was observed in 3 series I and 3 series II experiments, and the fluid empty alarm and the overheating alarm occurred once in series I and II, respectively. Although we allowed continued rapid infuser operation for up to 5 minutes after clot observation (secondary end point), it is conceivable that allowing the pump to continue running beyond this limited time of observation might have produced additional alarms and self-shutoff events.

Crystalloids and compatibility with blood pertaining to clot formation have been investigated in several in vitro studies with different designs, and current guidelines recommend not mixing LR solution with blood products during IV infusion because of its CaCl ₂ content. Two studies described clotting with the mixing of LR solution and whole blood.4,5 In one of these studies, clotting with LR solution and whole blood became visible after a 5-minute incubation period at room temperature.

LR solution and RBC combination clotting potential has been investigated separately. In 1 in vitro study, LR solution was mixed with RBCs in a 1:1 volume ratio (200 mL total), and macroscopic red cell aggregation was found with LR solution containing CaCl ₂ 5 g/L but not 2 g/L.6 Cull et al.7 examined different RBC/LR solution dilutions and noted clotting at dilutions of 1:1 but not 5:1, 3:1, and 2:1. They concluded that reconstitution of RBC with LR solution was safe when RBC were present in greater volume than with LR solution.7 A more recent in vitro study did not find any macroscopic or microscopic clot when NS or LR solution was added to RBC over a range of dilution ratios from 10:1 to 1:2 (crystalloid to RBC).8 In our experiment of mixing LR solution with RBC only, the crystalloid to RBC ratio was closer to 1:0.7, and we did not observe macroscopic coagulation or coil occlusion even with the addition of 1 g calcium.

When choosing crystalloids to combine with coagulation factor containing blood components, clinicians should also be mindful of the risk of hyperchloremic metabolic acidosis associated with administration of large amounts of NS.9

The systematic investigation of blood component and fluid combinations in rapid infusion devices in a simulated clinical practice setting is hampered by ethical limitations in the use of blood products eligible for use in humans. In our study, 1 important limitation is that we used blood products beyond their recommended storage date. The postexpiration ages of RBC and FTP were highly variable, which may have affected some of our results. With increasing age of RBC, structural changes take place, including increased osmotic fragility, hemolysis, and loss of deformability that may decrease effective clot formation.10,11 Aucar and Sheth12 demonstrated in vitro that RBC cold storage beyond 3 weeks after donation results in decreased coagulation with FTP.

The use of FTP after 5 days of cold storage at 1 to 6°C is not recommended for clinical use, and clotting factor activity decline may have affected our results. However, the decline of hemostatic factor activity in FTP is gradual and most significant for factors V and VIII within the first 24 hours after thawing.13 Furthermore, it has been demonstrated that coagulation factor activity in refrigerated FTP at 4°C for 2 weeks and up to 28 days was still sufficient for adequate hemostasis.14,15 Some of the differences in our findings may also be explained by the variable volume of each unit of blood product. Although RBC and FTP contain typically between 300 to 350 mL and 275 to 350 mL per unit, respectively, the amount in each experiment is never exactly the same, reflecting clinical practice. We also did not investigate microscopic clot formation because this would not be available during clinical care. In future trials, continuing pump operation beyond our observation in the presence of macroscopic clot formation may further clarify the effects of clot on pump operation.

In conclusion, we were unable to replicate the coil occlusion, overheating, and damage previously reported with use of the Belmont FMS 2000 by combining LR solution, NS, PL solution, or albumin with FTP and RBC and additional CaCl ₂. Our results suggest a role for calcium as an initiator of coagulation in blood products containing hemostatic factors. Although we used 200 mg CaCl ₂, there is the possibility that less CaCl ₂ may suffice to induce clotting in our model.

Although current accepted guidelines recommend avoiding LR solution for reconstitution of citrated blood components containing clotting factors and coadministration of calcium-containing medications,16 our results indicate that reconstituting blood products with LR solution may be possible in some circumstances. Additional studies are needed to explore this possibility.

DISCLOSURES

Name: Anupama Gopinath, MBChB, MRes.

Contribution: This author helped conduct the study, collect the data, analyze the data, and prepare the manuscript.

Attestation: Anupama Gopinath approved the final manuscript and attests to the integrity of the original data and the analysis reported in this manuscript.

Name: Chaim Nelson, MD.

Contribution: This author helped design the study, conduct the study, collect the data, and prepare the manuscript.

Attestation: Chaim Nelson approved the final manuscript and attests to the integrity of the original data and the analysis reported in this manuscript.

Name: Anupriya Gupta, MD.

Contribution: This author helped conduct the study, collect the data, and data entry.

Attestation: Anupriya Gupta approved the final manuscript and attests to the integrity of the original data and the analysis reported in this manuscript.

Name: Iwona Bonney, PhD.

Contribution: This author helped collect the data and prepare the manuscript.

Attestation: Iwona Bonney approved the final manuscript.

Name: Roman Schumann, MD.

Contribution: This author helped design the study, conduct the study, collect the data, analyze the data, and prepare the manuscript.

Attestation: Roman Schumann approved the final manuscript and attests to the integrity of the original data and the analysis reported in this manuscript and is the archival author.

This manuscript was handled by: Avery Tung, MD.

FOOTNOTE
a MAUDE-Manufacturer and User Facility Device Experience. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/TextSearch.cfm. Accessed July 31, 2015.
Cited Here...

REFERENCES

Supplemental Digital Content

© 2016 International Anesthesia Research Society

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Blood Products, Crystalloids, and Rapid Infusion: An... : Anesthesia & Analgesia

# data[].attributes.attachment_link.description
implicated. Lactated Ringer's (LR) solution is of particular concern as a diluent because of its calcium content. We sought to reproduce this failure mode using different infusion rates and different combinations of fluids for blood product reconstitution in the reservoir. We also introduced calcium chloride (CaCl2) to the mix to determine its role in macroscopic clot formation.

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Boyer, Richard B. PhD; Hocking, Kyle M. PhD; Booth, Garrett S. MD; Berry, James M. MD; Spain, Travis W. Cer ATT; Michaels, Damon R. CCRP; Sandberg, Warren S. MD, PhD; Pilla, Michael A. MD

doi: 10.1213/ANE.0000000000001110

Technology, Computing, and Simulation: Research Report

Rapid infusers are vital tools during massive hemorrhage and resuscitation. Sporadic reports of overheating and shutdown of the Belmont® Rapid Infuser, a commonly used system, have been attributed to 1-sided clot blockage of the fluid path. We investigated multiple causes of failure of this device.

Packed red blood cells and thawed fresh frozen plasma with normal saline solution were used as base fluids for serial 10-minute trials using standard disposable sets in 2 Belmont devices. Possible contributors to device failure, including calcium-containing solutions and external leakage currents, were evaluated. Thermographic images of the heater and disposable cartridges were recorded. The effects of complete unilateral clotting were modeled by sealing half of the disposable cartridge with epoxy.

Clotting on the surface of the heat exchanger coil increased with calcium concentration and was only observed at calcium concentrations >12.0 mmol/L ( P < 0.0001) in a 1:1 plasma:red blood cell mixture, resulting in high-pressure downstream occlusion alarms and interruption of flow.

Clot-based occlusion can be induced in the Belmont Rapid Infuser under unrealistic conditions. In the absence of complete unilateral flow blockage, we did not observe any significant overheating of the infuser under extreme operating conditions.

Supplemental Digital Content is available in the text.Published ahead of print December 23, 2015

From the *Vanderbilt University School of Medicine, Nashville, Tennessee; †Vanderbilt University, Nashville, Tennessee; ‡Vanderbilt University Medical Center, Nashville, Tennessee; and Departments of §Anesthesiology, ‖ Surgery, and ¶ Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee.

Accepted for publication October 28, 2015.

Published ahead of print December 23, 2015

Funding: This study was funded in part by an unrestricted grant from Belmont Corporation, Billerica, MA. Engineers from Belmont corporation participated in initial discussions to educate the authors about the design of the device. Belmont had no input into the design or conduct of the study nor did they participate in the analysis of the data or the drafting of the manuscript.

The authors declare no conflicts of interest.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's website.

Reprints will not be available from the authors.

Address correspondence to Michael A. Pilla, MD, Vanderbilt University Medical Center, Multi-Specialty Anesthesiology, 1301 Medical Center Dr., 4648 The Vanderbilt Clinic, Nashville, TN 37232. Address e-mail to michael.a.pilla@Vanderbilt.Edu.

Medical infusion pumps must deliver consistent performance across a wide range of environments, fluids, and operators. However, clinicians can at times push these devices beyond their performance specifications. Rapid infusers are a specialized subset of medical infusion pumps that deliver high flow rates of up to 1 L/min while heating the fluid to equal that of core body temperature, required for high-volume resuscitation.1-4 Because of the technical difficulty of heating fluid at high flow rates while maintaining fluid path isolation and sterility, there are few systems available currently in the United States. The Belmont® Rapid Infuser (FMS2000 "Fluid Management System," Belmont Instrument Corporation, Billerica, MA) is one of the most widely used rapid infusers.

There have been published reports of overheating and shutdown of unknown cause of Belmont Rapid Infusers during liver transplantation.5-7 Failures at 1 reporting center continued after the manufacturer replaced the involved devices and administration sets. Melting and deformation of the administration set have also been described. In the 2013 Food and Drug Administration (FDA) Manufacturer and User Facility Device Experience (MAUDE) data set, there are 4 adverse event reports involving the Belmont Rapid Infuser, including 2 describing intraoperative failures.8 Intraoperative failure may have serious and possibly life-threatening consequences, making thorough investigation and determination of the root cause of utmost importance.4,6

Previous reports hypothesized that calcium administered with blood products may lead to extracorporeal clot formation and resultant overheating of the administration set. As mentioned in the report by Xia et al.,7 another possible cause of rapid infuser malfunction is overheating of the heater coil causing clot formation, possibly initiating a self-perpetuating cycle of localized overheating and clot buildup. Blood cauterization may be initiated by heating elements that exceed 70°C, which could be produced by nonuniform thermal gradients of an inductive heater coil.9,10 Neither theory has been prospectively investigated.

There are anecdotal reports of overheating of the Belmont Rapid Infuser when the patient is also receiving intraoperative dialysis. Considering what is unique about dialysis that might affect interconnected systems, it is important to include electromagnetic energy in the form of leakage current. External electromagnetic sources are particularly abundant in the operating room, and dialysis machines are potential sources that have been found to produce leakage currents up to 1.2 mA in patient blood lines.11,12 A current of this magnitude would surpass the maximum allowable patient leakage current (100 and 500 μA in normal and single fault conditions, respectively), which is defined as the current flowing through a person to Earth by touching the device during either normal operation or when there is an interrupted Earth connection. However, the current is below the maximum allowable "mains voltage on applied parts" leakage (5 mA in type "Body Floating" devices), which is defined as the current that would flow if a main potential was applied to a lead in contact with the patient.13 Regardless of regulatory requirements, it is important to ensure that other medical devices in contact with the patient are not affecting the performance or safety of the Belmont Rapid Infuser.

In this study, we performed bench test analyses to investigate and identify or exclude potential contributors to overheating or failure of the Belmont Rapid Infuser in 1-to-1 frozen fresh plasma (FFP) to packed red blood cell (PRBC) transfusion. Specifically, we investigated whether calcium or external leakage currents can produce overheating and failure of the Belmont Rapid Infuser, and we investigated the performance of the device under normal conditions and the specific failure mode (clot occluding 1 limb of the fluid path) identified after the fact in case reports of device overheating.

METHODS

Vanderbilt University Medical Center Blood Bank provided PRBC and FFP. The study proposal was approved by the IRB of Vanderbilt University Medical Center.

Pilot Tests

Initial pilot testing was conducted before the design of experiments. Five scenarios were evaluated for inclusion in this study by conducting single-trial failure point analysis of the Belmont Rapid Infuser. These pilot experiments were performed with presumed high-impact variables with the intention of identifying pump failure points, and they were not intended to result in statistical findings. Thermographic imaging, clotting observations, and pump alarms were used to evaluate the following scenarios and operating conditions. One Belmont Rapid Infuser was used for all pilot testing. Belmont 3-Spike disposable tubing sets (903-00006P, Belmont Instrument Corporation) and 3.0-L reservoirs (903-00018P, Belmont Instrument Corporation) were configured to recycle the fluids through the pump by connecting the distal end of the tubing set to the inlet port on the reservoir. Disposables and fluids were discarded and replaced after each of the following scenarios.

1. Extended periods of low-flow or no-flow operation

2. Solution: 3 units PRBC and 3 units FFP

3. Operation: 1 hour at 100 mL/min, then 4 hours at 10 mL/min, then 4 hours at 2.5 mL/min, then 1 hour at 500 mL/min

4. Extended periods of no-flow operation with calcium admixture (10% CaCl₂ solution)

5. Solution: 3 units PRBC, 3 units FFP, and 800 mg calcium chloride (final concentration 4.8 mM)

6. Operation: 24 hours at 0 mL/min, then 10 minutes at 100 mL/min, then 10 minutes at 10 mL/min, then 10 minutes at 500 mL/min

7. High-dose calcium admixture (10% CaCl₂ solution)

8. Solution: 3 units PRBC, 3 units FFP, and 2000 mg calcium chloride (final concentration 12.0 mM)

9. Operation: 10 minutes at 10 mL/min, then 10 minutes at 100 mL/min, then 10 minutes at 500 mL/min

10. Heater coil occlusion (epoxy occlusion of the left limb of the Belmont heater coil)

11. Solution: 3 units PRBC and 3 units FFP

12. Operation: 10 minutes at 10 mL/min, 10 minutes at 100 mL/min, 10 minutes at 500 mL/min

13. Electromagnetic interference (distal tubing connected to constant 10-mA current source, simulating applied-part leakage current during a single fault "Earth interrupt" condition)

14. Solution: 3 units PRBC and 3 units FFP

15. Operation: 10 minutes at 10 mL/min, then 10 minutes at 100 mL/min, then 10 minutes at 500 mL/min

The following methods pertain to the continued evaluation of the pump after completion of initial pilot testing. Methods used in this evaluation are similar to those used in pilot testing but optimized for study feasibility and statistical power.

Equipment and Infusion Fluids

Two Belmont Rapid Infuser (FMS2000, Belmont Instrument Corporation) units were used in this study interchangeably. The pumps were certified by the manufacturer to be within manufacturer's specifications, and standard Belmont 3-Spike disposable tubing sets (REF 903-00006P, Belmont Instrument Corporation) and 3-L reservoirs (903-00018P, Belmont Instrument Corporation) were used for all experiments. Tubing sets were replaced after each series of experiments. The Belmont Rapid Infuser administration set contains 16 chemically passivated stainless steel rings that heat the passing fluid through electromagnetic induction.14 Briefly, a primary transformer coil located in the pump creates an alternating electromagnetic field that induces current in the secondary disposable coils, leading to heating of the resistive metal elements and passing fluid.15 Fluid flow enters the bottom of the ring, splits left and right to flow over the heater coils, and rejoins at the top of the heater (Supplemental Digital Content 1, Supplemental Figure 1, http://links.lww.com/AA/B323). Flow is assumed to be symmetric.

Pump alarm and error log data were recorded using a serial port connection to a workstation running HyperTerminal (Microsoft HyperTerminal, Microsoft Corporation, Redmond, WA). The outlet of the disposable tubing set was connected to an inlet at the top of the pump reservoir at 1 m above the ground for fluid collection and recirculation ( Fig. 1). One unit of PRBC and 1 ABO-compatible unit of FFP were combined as the base fluids for each trial. The infuser was primed with normal saline before each trial.

For all the trials below, we tested flow rates of 10, 100, and 500 mL/min. Each trial was run for 10 minutes with minimal interruption between the end of each run and the measurement of coil temperature and evaluation of clotting in the heater coil. All trials were run in triplicate for a total of 3 × 10 minutes in each flow condition. There was a 5-minute cool-down period between flow conditions for a full test sequence of 10 mL/min, 5-minute cool down, 100 mL/min, 5-minute cool down, and 500 mL/min, 5-minute cool down.

Calcium Additives

Calcium effects were evaluated with the addition of calcium chloride admixture (1000 mg of 10% CaCl ₂) to the base fluids in 100-mg increments up to 1000 mg in serial trials in triplicate as described earlier. This is equivalent to an experimental CaCl ₂ concentration range of 1.5 to 15.0 mmol/L. This range was chosen based on the concentration of calcium in lactated Ringer's solution (1.5 mmol/L) and up to 10-fold this value. The tubing set was discarded and replaced after each complete set of incremental calcium trials or after observed clotting for a full test sequence of:

100 mg: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool-down, ...

200 mg: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down, ...

1000 mg: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down

Discard and replace tubing set and repeat 2 times

External Leakage Currents

Needle electrodes inserted into the disposable tubing set ( Fig. 2) were connected to a constant current source (Programmable Power Supply 9130, BK Precision, Yorba Linda, CA) to simulate a leakage current on the applied part with a single fault (Earth interrupt) condition. After priming of the disposable tubing set, the power supply was set to apply a constant current of 2, 4, 6, 8, and 10 mA in serial trials with the base fluids in triplicate as described earlier. Applied current was verified with a digital multimeter (Fluke 113, Fluke Corporation, Everett, WA) in series with the electrodes. The tubing set was discarded and replaced after each complete set of incremental current trials or after observed clotting for a full test sequence of:

1 mA: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down

2 mA: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down, ...

10 mA: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down

Discard and replace tubing set and repeat 2 times

Thermographic Imaging

An infrared camera (FLIR i7, FLIR Systems, Wilsonville, OR) was used to record thermographic images of the Belmont pump and disposable cartridges. The infrared camera was initially calibrated to ±2°C with a sensitivity of <0.1°C at room temperature. Images of the cartridge heater coils were captured immediately after each pump trial with the pump door fixed open. Images were collected within 15 seconds of shutting off the pump to minimize the cooling effects. The coils were imaged in entirety, and regions of interest were digitally segmented during analysis. Commercial software (FLIR QuickReport version 1.2, FLIR Systems) was used for analysis of thermal images and detection of absolute and relative temperature in 6 equally spaced regions of interest around the heater coil surface.

Unilateral Flow Blockage

The Belmont disposable heater coil is a sealed cartridge containing parallel flow channels separated by 16 chemically passivated stainless steel rings. Unilateral occlusion of the heater coil, as was reported in overheating failure events, was evaluated in this study by occluding a number of the parallel flow channels on the left side of the coil with epoxy. Three Belmont disposable sets were occluded with epoxy in the lower left quadrant of the heater coil (the location of previously reported occlusions discovered after overheating failures reported in the literature) using epoxy sealant (Epoxy Instant Mix, Loctite, Westlake, OH) injected between 4, 8, or 16 of the 16 heater coil rings, generating 25%, 50%, or 100% unilateral occlusion, respectively. Modified sets were reinforced with epoxy putty (EP-200, RectorSeal, Houston, TX) and allowed to harden for 24 hours before usage. Each of the unilaterally blocked disposable sets was evaluated in 5-fold trials at 10, 100, and 500 mL/min for 10 minutes at each flow rate without interruption. The tubing set was discarded and replaced after completion of each occlusion condition for a full test sequence of:

25%: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down for 5 times

Discard and replace tubing set

50%: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down for 5 times

Discard and replace tubing set

100%: 10 mL/min, cool down, 100 mL/min, cool down, 500 mL/min, cool down for 5 times

Statistical Methods

Repeated measures thermographic images were evaluated with mixed-effects Standard Least Squares fit models using restricted maximum likelihood fitting and unrestricted parameterization for variance components. Parts (disposable sets) and trial order were evaluated as random effects in the constructed model. Fixed effects (calcium, flow rates, and leakage current) were evaluated with F-ratio, and significance was determined as P < 0.01. Clotting events were evaluated with a 3-level mixed effects logistic regression with binomial distribution and random effect intercepts for parts and trial order (Supplemental Digital Content 2, Supplemental Figure 2, http://links.lww.com/AA/B324). Fisher exact test was used for evaluating the calcium concentration threshold of clotting. Tests were 2 tailed with a significance level of 0.05. Because of factors that are difficult to reliably control (i.e., manufacturing of epoxy-occluded units), unilateral flow blockage trials are reported as secondary observational findings and not subjected to statistical analysis.

RESULTS

In pilot testing, we observed no clotting or alarms with up to 4 hours of low-flow operation (2.5 and 10 mL/min) in calcium-free FFP/PRBC solution. In addition, we completed 24 hours of pump no-flow with FFP/PRBC solution containing 4.8 mM calcium chloride without observing clotting or alarms when the pump resumed operation. Because extended periods of low-flow appeared to have minimal effects on pump performance, we continued pilot testing using a shorter protocol with 10 minutes at 10 mL/min, 10 minutes at 100 mL/min, and 10 minutes at 500 mL/min. Three initial scenarios at intentionally high values were found to produce clotting in our pilot testing: high-dose calcium chloride additive, heater coil occlusion, and electromagnetic interference (12.0 mM CaCl ₂, 100% occlusion, and 10 mA, respectively). We then designed the proceeding study to further evaluate the dose response of CaCl ₂, epoxy occlusion, and external leakage currents around these maximum conditions.

Addition of calcium chloride (CaCl ₂) to the FFP/PRBC mix induced clotting at supranormal CaCl ₂ concentrations. Dose-response curves were generated for CaCl ₂-induced clotting at flow rates of 10, 100, and 500 mL/min ( Figs. 3-6). Clot observations, thermal images, and pump alarms were recorded for each trial. The first trial for each run, e.g., 100 mg CaCl ₂ trial, is not included in this analysis owing to the presence of pump warm-up artifact. Clots were not observed on the disposable coil <800 mg (12.0 mmol/L) of added CaCl ₂, but only observed at calcium concentrations >12.0 mmol/L ( P < 0.0001; Supplemental Digital Content 3, Supplemental Figure 3, http://links.lww.com/AA/B325). Above this threshold calcium level, dichotomous clot presence increased with the concentration of CaCl ₂, and this effect was found to be significant in a mixed-effects logistic regression model (Supplemental Digital Content 2, Supplemental Figure 2, http://links.lww.com/AA/B324). An exponential model of clot accumulation was chosen based on prior in vitro studies that have shown this relationship.16 At least 1 clot was observed in the disposable heater coil at 10, 100, and 500 mL/min after the addition of 800 mg (12.0 mmol/L), 900 mg (13.5 mmol/L), and 1000 mg (15.0 mmol/L) of CaCl ₂, respectively. In addition, all the observed clots produced a high-pressure alarm and pump cessation.

Average and maximum coil temperatures were found to be independent of the concentration of CaCl ₂. However, left-right temperature difference showed a decreasing trend with the addition of calcium. This trend was more pronounced at a high flow rate (500 mL/min) in which the temperature difference was negative, representing a higher temperature on the right side of the coil. However, the absolute left-right temperature difference remained <0.6°C at all flow rates and CaCl ₂ concentrations tested. Average coil temperatures were significantly increased with high pump flow rate compared with low pump flow rate ( P < 0.0001, 2-tailed paired Student t test; Fig. 7). Temperature variation with flow rate is expected because the heater coils have less contact time with fluid as flow rate is increased, necessitating an increase in heater power. However, this does not explain the presence of a left-right temperature difference in the coil or how this temperature gradient changes with the addition of calcium.

Since previous reports of overheating clustered in a single hospital, we conjectured that there was some unique aspect of that environment, such as another grossly malfunctioning device, that might have contributed to the failures. We then attempted to reproduce plausible scenarios involving other malfunctioning equipment. The effects of high external leakage currents between 2 and 10 mA were assessed using a constant current source ( Fig. 2). There was no significant effect of applied leakage currents on coil temperature. Clotting of the disposable set and 1 alarm (downstream occlusion) were observed in 2 of the maximum current (10 mA) trials at 10 mL/min flow rate. Hot spots were not observed in the coil during these trials.

Secondary Observations

To explain the formation of temperature gradients with the addition of calcium, we evaluated left-right temperature differences in the heater coil during unilateral flow blockage, thereby mimicking the flow blockage because of clotting. Unilateral flow blockage was created by injecting epoxy into the left side of the heater coil. We evaluated the effects of 25%, 50%, and 100% unilateral flow blockage ( Fig. 8). Moderate increases in left-right temperature difference from baseline were observed at 25% unilateral blockage, whereas absolute left and right temperatures remained near baseline. This trend continued with 50% unilateral blockage, resulting in the left-right temperature differences over 10-fold the baseline values. Clotting and an alarm (fluid out) occurred during the last 500 mL/min run with the 50% occluded set. The 100% unilateral blockage produced high temperatures up to 78°C in the left side of the coil; however, the right side of the coil and the distal tubing remained in the normal range. The pump alarmed (heating fault) at the first 500 mL/min run with the 100% occluded set, but the pump remained operational after reboot and repriming of the set. A burnt plastic odor was observed in the final run of this trial, and the disposable was found to have melted near the epoxy over the lower left quadrant of the coil ( Fig. 9). Although the maximum temperature found with thermographic imaging was 78°C, deformation of the heat exchanger suggests that the plastic housing reached higher temperatures during operation, possibly approaching the melting point of polycarbonate at 155°C.

DISCUSSION

We set out to induce failure of the Belmont Rapid Infuser using triggers hypothesized post hoc in case reports of overheating failures during use. We discovered in bench testing that extraneous calcium administration or leakage current could induce clot formation in the disposables. Moreover, very high calcium concentrations (equivalent to rapid administration of 1000 mg CaCl ₂ into approximately 1500-mL reservoir volume) or supranormal leakage currents were required to induce clotting. Replication of the end state discovered in field-use failures (hemi-occlusion of the heater coil) produces high local overheating but no overheating in the patient-connected flow path.

In the United States, infusion pump manufacturing is regulated by the FDA.17 The FDA requires compliance with International Electrotechnical Commission (IEC) 60601 standards on infusion pump safety and performance to protect against medication delivery errors and hardware malfunctions.18 Despite recent tightening of these regulatory controls, mechanical failures leading to adverse events continue to occur. Battery discharge, erroneous alarms, improper shutoff, and overheating are only a few of numerous documented cases of infusion pump malfunction.6 In 2013, there were >11,000 infusion pump-related adverse events reported to the MAUDE database by mandatory and voluntary reporters.8 Overheating of the Belmont Rapid Infuser has been described in the literature, but only 4 of the 2013 MAUDE reports involved this device, indicating that overheating of the Belmont is a rare event.5,7,8,19

Previous reports have suggested the possibility that calcium administered with blood products may lead to extracorporeal clot formation and resultant overheating of the administration set. However, it is well known to health care providers that calcium-containing solutions should not be combined with blood products because of increased clotting risk.20 This risk has prompted rapid infuser manufacturers to add warnings against the addition of calcium-containing solutions to their product labeling. However, the effectiveness of these warnings is limited by situational necessity during urgent transfusions and anecdotal policies on the acceptable calcium range. Based on the physician, nurse, and technician interviews, there are variations in the adherence to these warnings, including the use of lactated Ringer's solution or autologous recovered blood.a

As mentioned in a previous report by Xia et al.,7 another possible, although unproved, cause of rapid infuser malfunction is overheating of the heater coil causing clot formation and possibly initiating a self-perpetuating cycle of localized overheating and clot buildup. This situation may also be initiated by nonuniform thermal gradients produced by the heater element.9,10 The rate of energy transformed to heat in the model induction heater can be calculated with Ohm law and Maxwell equations.21,22 However, an important source of variation from the theoretical calculation is the environment in which the system is operating. Specifically, the presence of additional sources of electromagnetic charge and current will produce deviations from the model system.21 Although this can be controlled with system sensors and feedback, transient fluctuations in the thermal gradient are unavoidable.22

Based on the findings in our study, it is possible that there are rare incidents of calcium-containing solutions being injected directly into either the reservoir or the traveling retrograde into the heater of the Belmont Rapid Infuser, increasing the rate of clot formation and possibly initiating a cycle of unilateral blockage and overheating. This is supported by previous studies of overheated and clotted Belmont disposables in which calcium has been detected in the tubing set. (Although calcium could be released also through hemolysis of erythrocytes in occluded disposables stored in uncontrolled conditions before assay.) Calcium acts as a cofactor that catalyzes several reactions in the clotting cascade and accelerates the formation of fibrin clots.20 Trisodium citrate is used to chelate calcium in blood products and thereby to prevent clotting.23 FFP and PRBC citrate concentrations are approximately 20 and 6.7 mmol/L respectively, which should be capable of chelating at least an equivalent concentration of calcium. This supports our finding that clotting was observed only at calcium concentrations of ≥12.0 mmol/L, far beyond the calcium concentration of lactated Ringer's solution.

Although not statistically verified in this study, Belmont Instrument Corporation has verified a slight right-sided flow preference in the heater coil; the difference in flow rate may affect the temperature of the coil and may create different shear stresses in parts of the coil. The low velocity side of the coil would have decreased shear stresses, which allow for coagulation to occur more easily. It has been shown that clot formation is greatly affected between 30 and 150 dynes/cm ², associated with decreased clot formation as shear stress is increased.24 Although temperature in the coil did not change significantly until blockage occurred, the only feedback mechanism for temperature in the Belmont Rapid Infuser is the outflowing blood temperature, allowing the coil to continuously heat the clotted blood on the occluded section of the coil. To test this principle, epoxy was used to block flow in the area most often found clotted in our testing, the lower left quadrant. When flow was completely obstructed, blood continued to flow through the nonobstructed portion of the coil, and, as heat was added over time, the obstructed portion became hot enough to melt the plastic ( Fig. 9). To prevent this overheating, we recommend that disposable sets be discarded immediately after the first alarm and replaced with a new set. We have also recommended to the manufacturer the addition of a direct coil temperature sensor for detection of coil overheating.

External electromagnetic sources are particularly abundant in the operating room, and there are anecdotal reports of overheating of the Belmont Rapid Infuser during intraoperative dialysis. Dialysis machines are one potential source that has been found to produce leakage currents up to 1.2 mA in patient blood lines.11,12 It is important to note that this current far surpasses the maximum allowable patient leakage current described in IEC 60601-1 for type cardiac floating devices, which is 10 μA in normal condition and 50 μA in single fault condition. As such, any type cardiac floating medical device that reaches the current levels tested in this study would be severely outside of the acceptable range for leakage currents.13 However, because of the rarity of Belmont Rapid Infuser failure events and clustering at a single medical center, we considered it necessary to test pump performance against a higher level of electromagnetic interference. External leakage currents within the IEC 60601-1 allowable limits did not affect pump performance during this study. Clots were observed in the coil in 50% of the trials at 10 mA applied current, but no overheating or cessation of pumping was observed. It is important to note that line isolation monitors typically alarm at ≤5 mA and should, therefore, prevent this scenario.

Our study is subject to important limitations. As a bench study in a controlled setting, it is difficult to replicate several key features found in the clinical use of the Belmont Rapid Infuser. Specifically, the device is commonly clinically used to deliver dozens of units of PRBC ± FFP, frequently with alternating high/low flow rates during actual cases. Often, a thick layer of "goop," likely clotted blood, is observed on the large surface area filter between the filling ports and the fluid uptake inlet inside the high-capacity reservoir. There is no reason to expect that similar gel formation does not continue downstream of this filter. It is also possible for small clots to form in the reservoir distal to the filter and lodge in the heater coil at low flow rates, but this proposal remains purely speculative. In addition, the number of trials in this study and safety concerns regarding unobserved pump operation necessitated short (3 × 10 minutes) pump intervals. Although not tested in this study, it may be possible that increased hemolysis and stasis during extended periods of low-flow could increase the rate of clotting events. Conversely, in our experiments, we recycled warmed PRBC/FFP mix back into the reservoir, which should, if anything, increase the potential for clot formation. Belmont Instrument Corporation reported observations of clots in the heater coil after 4 hours of low flow (0-10 mL/min) using citrated porcine blood containing 5.4 mM calcium, 55% lower than the observed calcium-clotting threshold in this study (Herzlinger G, President, Belmont Instrument Corp., personal communication, 2013).

In summary, we did not observe any significant overheating of the Belmont Rapid Infuser under extreme operating conditions. In addition, we were only able to cause pump failure with complete blockage of the heat exchanger with epoxy. We redemonstrated that the addition of large amounts of CaCl ₂ to the reservoir will result in clotting of blood products, reinforcing the recommendation that to minimize the risk of coagulation and pump shutdown, calcium-containing products should never be administered in the same line as citrated blood products. Finally, intraoperative dialysis during use of the Belmont Rapid Infuser would be unlikely to cause the failures observed, because leakage currents would have to greatly exceed allowable earth leakage current thresholds in normal operation or single fault conditions.

DISCLOSURES

Name: Richard B. Boyer, PhD.

Contribution: This author helped design the study, conduct the study, analyze the data, and write the manuscript.

Attestation: Richard B. Boyer has seen the original study data, reviewed the analysis of the data, approved the final manuscript, and is the author responsible for archiving the study files.

Name: Kyle M. Hocking, PhD.

Contribution: This author helped design the study, conduct the study, analyze the data, and write the manuscript.

Attestation: Kyle M. Hocking has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Garrett S. Booth, MD.

Contribution: This author helped design the study, conduct the study, and write the manuscript.

Attestation: Garrett S. Booth has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: James M. Berry, MD.

Contribution: This author helped design the study, conduct the study, and write the manuscript.

Attestation: James M. Berry has seen the original study data, reviewed the analysis of the data, approved the final manuscript, and is the author responsible for archiving the study files.

Name: Travis W. Spain, Cer ATT.

Contribution: This author helped conduct the study and analyze the data.

Attestation: Travis W. Spain has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Damon R. Michaels, CCRP.

Contribution: This author helped design the study and conduct the study.

Attestation: Damon R. Michaels has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Warren S. Sandberg, MD, PhD.

Contribution: This author helped design the study, conduct the study, analyze the data, and write the manuscript.

Attestation: Warren S. Sandberg has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

Name: Michael A. Pilla, MD.

Contribution: This author helped design the study, conduct the study, analyze the data, and write the manuscript.

Attestation: Michael A. Pilla has seen the original study data, reviewed the analysis of the data, and approved the final manuscript.

This manuscript was handled by: Maxime Cannesson, MD, PhD.

ACKNOWLEDGMENTS

The authors thank Martha W. Tanner, BA, Department of Anesthesiology, Office of the Chair, for her assistance in the preparation of this manuscript.

FOOTNOTE
a Among the authors' >20 years experience with the Belmont Rapid Infuser, our only overheat/occlusion failure occurred during an extremis exsanguination event in which whole blood collected from the field by autotransfusion suction was routed directly into the reservoir without washing and inffused through the heater. Unilateral clotting of the heater rings was observed after the device shutoff because of overheat warnings (WSS, unpublished observations).
Cited Here...

REFERENCES

15. Hurley W, Kassakian JG. Induction heating of circular ferromagnetic plates. IEEE Trans Magn. 1979;15:1174-81

20. Brass EP, Forman WB, Edwards RV, Lindan O. Fibrin formation: effect of calcium ions. Blood. 1978;52:654-8

21. Vaughan JT, Williamson JW. Design of induction-heating coils for cylindrical nonmagnetic loads. Electr Eng. 1945;64:587-92

© 2016 International Anesthesia Research Society

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An Evaluation of Induced Failure Modes in the Belmont®... : Anesthesia & Analgesia

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of this device. METHODS: Packed red blood cells and thawed fresh frozen plasma with normal saline solution were used as base fluids for serial 10-minute trials using standard disposable sets in 2 Belmont devices. Possible contributors to device failure, including calcium-containing solutions and external leakage currents, were evaluated.

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The Belmont® Rapid Infuser RI-2 Instructional Video - Full (Updated)

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Updated full version of The Belmont® Rapid Infuser RI-2 instructional video. Video Guide (Timestamp): 01. Introduction (00:05) 02. Setup (00:45) 03. Priming (03:11) 04. Operation (04:35) 05. Alarms & Alerts (08:01) 06. Optional 3.0L Reservoir (11:15) 07. Consumables (12:15)

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How long does the Belmont take to infuse 1Liter of blood?

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How long does the Belmont take to infuse 1Liter of blood?

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The Belmont Rapid Infuser is a proven lifesaver, tested in high stress conditions in the war zone in the Middle East, and in operating rooms around the world.