Blood management: a primer for clinicians

Review of Evidence Supporting the Arista™ Absorbable Powder Hemostat

Background

Uncontrolled and diffuse bleeding is a dreaded event during open and laparoscopic surgery that may lead to postoperative complications, obstruction of the surgical field that reduces visualization, and prolonged operating times. Powder hemostats can be used to control bleeding and are easy to use, have a safe profile, and can achieve broad coverage area at a low cost.

Methods

A strategic literature search of peer-reviewed, English language studies was conducted to capture evidence on the clinical efficacy and safety of a Microporous Polysaccharide Hemosphere (MPH) based Hemostat (Arista™ Absorbable Hemostat (Arista™ AH)).

Results

Six preclinical studies were found which supported the use of MPH in various animal models of laparoscopic and open surgery, all of which demonstrated its safety and efficacy. Five single-arm and 11 comparative clinical studies similarly supported the efficacy and safety of MPH in various surgery types, including cardiac, renal, and dermatologic surgery.

Conclusion

Published evidence supports the safe and effective use of MPH across a variety of surgical settings.

Liver protection and hemostatic effects of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst. (AE) is a Chinese medicinal herb that is traditionally used to treat various circulatory diseases. It exhibits certain effects, such as the promotion of blood circulation and cooling, rash clearance, and detoxification.

AIM OF THE STUDY

This study was designed to explore the hepatoprotective and hemostatic effects of the ethyl acetate extract of AE in rats with carbon tetrachloride (CCl4)-induced liver injury.

MATERIALS AND METHODS

Wistar rats were treated via oral gavage with different doses of the ethyl acetate extract of AE (3.5, 7, or 14 g kg^-1·day^-1) for 14 consecutive days, following which hemostatic and liver function tests were conducted. For the hemostatic tests, the platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretion from blood platelets, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen levels were measured at the end of the treatment period. For the liver function tests, 0.25 mL/200 g (1.25 mL kg^-1·day^-1) of olive oil was injected into the abdominal cavity of the control rats, whereas 15% CCl₄ plus olive oil (prescription: 7.5 mL CCl₄ + 42.5 olive oil) was injected into that of the treated rats at 1 h after extract administration on day 6, 13, and 20. Additionally, food and water were withheld from all the animals. On the following day, the rats were anesthetized and their albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), gamma-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), reactive oxygen species (ROS), methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were measured. Glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) levels among the groups were determined using a one-way analysis of variance.

RESULTS

The platelet count and blood platelet aggregation, blood platelet adhesion to fibrinogen and PF-4 secretion levels were significantly increased in the (3.5 g kg^-1 day^-1) AE group as compared to those in the control group (all p < 0.001; for the 7 and 14 g kg^-1 day^-1 AE groups, all p > 0.05, respectively). Although the PT and aPTT were not affected by the AE extract (all p > 0.05), the TT was reduced and the FIB levels were significantly increased in all AE groups (p < 0.05). Liver function tests showed that CCl₄ caused significant liver damage, thereby decreasing the albumin, SOD, CAT, GSH, GST, GR, and GPx levels, while increasing the AST, ALT, ALP, SGOT, SGPT, GGT, LDH, ROS, and MDA levels (all p < 0.001). By contrast, treatment with the different doses of AE extract reversed the CCl₄ effects on all these parameters. Compared with the levels in the CCl₄ group, the GSH and GR levels in the three AE groups (3.5, 7, and 14 g kg^-1·day^-1) were significantly higher (p < 0.05, p < 0.01, and p < 0.001, respectively), whereas the differences in the other parameters for these three groups were all at the significance levels of p < 0.05, p < 0.05, and p < 0.01, respectively.

CONCLUSIONS

AE extracts administered orally exhibited hepatoprotective activity by affecting platelet production and blood coagulation and ameliorating liver function-damaging modifications. Specifically, a dosage of 3.5 g kg^-1·day^-1 resulted in the most optimal effects.

Isolation, Characterization and Evaluation of Collagen from Jellyfish Rhopilema esculentum Kishinouye for Use in Hemostatic Applications

Hemostat has been a crucial focus since human body is unable to control massive blood loss, and collagen proves to be an effective hemostat in previous studies. In this study, collagen was isolated from the mesoglea of jellyfish Rhopilema esculentum Kishinouye and its hemostatic property was studied. The yields of acid-soluble collagen (ASC) and pepsin-soluble (PSC) were 0.12% and 0.28% respectively. The SDS-PAGE patterns indicated that the collagen extracted from jellyfish mesoglea was type I collagen. The lyophilized jellyfish collagen sponges were cross-linked with EDC and interconnected networks in the sponges were revealed by scanning electron microscope (SEM). Collagen sponges exhibited higher water absorption rates than medical gauze and EDC/NHS cross-linking method could improve the stability of the collagen sponges. Compared with medical gauze groups, the blood clotting indexes (BCIs) of collagen sponges were significantly decreased (P < 0.05) and the concentration of collagen also had an influence on the hemostatic property (P < 0.05). Collagen sponges had an improved hemostatic ability compared to the gauze control in tail amputation rat models. Hemostatic mechanism studies showed that hemocytes and platelets could adhere and aggregate on the surface of collagen sponge. All properties make jellyfish collagen sponge to be a suitable candidate used as hemostatic material and for wound healing applications.

S2'-subsite variations between human and mouse enzymes (plasmin, factor XIa, kallikrein) elucidate inhibition differences by tissue factor pathway inhibitor -2 domain1-wild-type, Leu17Arg-mutant and aprotinin

Essentials Current antifibrinolytics - aminocaproic acid and tranexamic acid-can cause seizures or renal injury. KD1L17R -KT , aprotinin and tranexamic acid were tested in a modified mouse tail-amputation model. S2'-subsite variations between human and mouse factor XIa result in vastly different inhibition profiles. KD1L17R -KT reduces blood loss and D-dimer levels in mouse with unobserved seizures or renal injury.

SUMMARY

Background Using tissue factor pathway inhibitor (TFPI)-2 Kunitz domain1 (KD1), we obtained a bifunctional antifibrinolytic molecule (KD1L17R -KT ) with C-terminal lysine (kringle domain binding) and P2'-residue arginine (improved specificity towards plasmin). KD1L17R -KT strongly inhibited human plasmin (hPm), with no inhibition of human kallikrein (hKLK) or factor XIa (hXIa). Furthermore, KD1L17R -KT reduced blood loss comparable to aprotinin in a mouse liver-laceration model of organ hemorrhage. However, effectiveness of these antifibrinolytic agents in a model of hemorrhage mimicking extremity trauma and their inhibition efficiencies for mouse enzymes (mPm, mKLK or mXIa) remain to be determined. Objective To determine potential differences in inhibition constants of various antifibrinolytic agents against mouse and human enzymes and test their effectiveness in a modified mouse tail-amputation hemorrhage model. Methods/Results Unexpectedly, mXIa was inhibited with ~ 17-fold increased affinity by aprotinin (Ki ~ 20 nm) and with measurable affinity for KD1L17R -KT (Ki ~ 3 μm); in contrast, KD1WT -VT inhibited hXIa or mXIa with similar affinity. Compared with hPm, mPm had ~ 3-fold reduced affinity, whereas species specificity for hKLK and mKLK was comparable for each inhibitor. S2'-subsite variations largely accounted for the observed differences. KD1L17R -KT and aprotinin were more effective than KD1WT -VT or tranexamic acid in inhibiting tPA-induced mouse plasma clot lysis. Further, KD1L17R -KT was more effective than KD1WT -VT and was comparable to aprotinin and tranexamic acid in reducing blood loss and D-dimer levels in the mouse tail-amputation model. Conclusions Inhibitor potencies differ between antifibrinolytic agents against human and mouse enzymes. KD1L17R -KT is effective in reducing blood loss in a tail-amputation model that mimics extremity injury.

Transfusion monitoring: care practice analysis in a public teaching hospital

Objective

To analyze the process of recording transfusion monitoring at a public teaching hospital.

Methods

A descriptive and retrospective study with a quantitative approach, analyzing the instruments to record transfusion monitoring at a public hospital in a city in the State of Minas Gerais (MG). Data were collected on the correct completion of the instrument, time elapsed from transfusions, records of vital signs, type of blood component more frequently transfused, and hospital unit where transfusion was performed.

Results

A total of 1,012 records were analyzed, and 53.4% of them had errors in filling in the instruments, 6% of transfusions started after the recommended time, and 9.3% of patients had no vital signs registered.

Conclusion

Failures were identified in the process of recording transfusion monitoring, and they could result in more adverse events related to the administration of blood components. Planning and implementing strategies to enhance recording and to improve care delivered are challenging.

Similar patient outcomes yet different hospital costs between flowable hemostatic agents

INTRODUCTION

SURGIFLO and FLOSEAL are absorbable gelatin-based products that form hemostatic matrices. These products are indicated as adjuncts to hemostasis when control of bleeding by conventional surgical techniques (such as suture, ligature or cautery) is ineffective or impractical. This study analyzed the effect of surgery time and the choice of product on cost to the hospital and patient outcomes.

METHODS

The data source was the Premier Hospital database from January 1, 2010-June 30, 2012. Eligible patients were ≥18 years of age with a spinal fusion or refusion surgery with either SURGIFLO (Ethicon Inc.) or FLOSEAL (Baxter International Inc.). The hospital Charge Master was used to identify the amount of flowable product, whether it included Thrombin, and the cost. Multivariable models were performed on overall cost and likelihood of surgical complications. All models were adjusted for patient demographics and severity as well as hospital, and surgical characteristics.

RESULTS

A total of 24,882 patient records from 121 hospitals were analysed, which included 15,088 FLOSEAL records and 9794 SURGIFLO records, with 1498 SURGIFLO with Thrombin patients. Little or no differences in surgical complications were found between surgeries with SURGIFLO vs. surgery with FLOSEAL. Regression models showed a reduction in cost of $65 associated with use of SURGIFLO with Thrombin and an additional $21 reduction in hospital cost for each additional hour of surgery. Modeling which accounts for hospital fixed effects suggest that, in addition to a gap of ∼$300 favoring SURGIFLO with Thrombin, every additional hour of surgery was associated with an additional reduction in hospital costs of ∼$26.

CONCLUSIONS

While the choice of flowable product had no effect on clinical outcomes, use of SURGIFLO was associated with hospital cost savings for flowable product. These savings increased with the length of surgery, even when controlling for the amount of flowable product (mL) used.

Hospital economic impact from hemostatic matrix usage in cardiac surgery

OBJECTIVE

Improved health outcomes can result in economic savings for hospitals and payers. While effectiveness of topical hemostatic agents in cardiac surgery has been demonstrated, evaluations of their economic benefit are limited. This study quantifies the cost consequences to hospitals, based on clinical outcomes, from using a flowable hemostatic matrix vs non-flowable topical hemostatic agents in cardiac surgery.

RESEARCH DESIGN AND METHODS

Applying clinical outcomes from a prospective randomized clinical trial, a cost consequence framework was utilized to model the economic impact of comparator groups. From that study, clinical outcomes were obtained and analyzed for a flowable hemostatic matrix (FLOSEAL, Baxter Healthcare Corporation) vs non-flowable topical hemostats (SURGICEL Nu-Knit, Ethicon-Johnson & Johnson; GELFOAM, Pfizer). Costing analyses focused on the following outcomes: complications, blood transfusions, surgical revisions, and operating room (OR) time. Cardiac surgery costs were analyzed and expressed in 2012 US dollars based on available literature searches and US data. Comparator group variability in cost consequences (i.e., cost savings) was calculated based on annualized impact and scenario testing.

RESULTS

RESULTS suggest that if a flowable hemostatic matrix (rather than a non-flowable hemostat) was utilized exclusively in 600 mixed cardiac surgeries annually, a hospital could improve patient outcomes by a reduction of 33 major complications, 76 minor complications, 54 surgical revisions, 194 transfusions, and 242 h of OR time. These outcomes correspond to a net annualized cost consequence savings of $5.38 million, with complication avoidance as the largest contributor.

CONCLUSIONS

This cost consequence framework and supportive modeling was used to evaluate the hospital economic impact of outcomes resulting from the usage of various hemostatic agents. These analyses support that cost savings can be achieved from routine use of a flowable hemostatic matrix, rather than a non-flowable topical hemostat, in cardiac surgery.

Patient-centered blood management

BACKGROUND

Transfusions are common in hospitalized patients but carry significant risk, with associated morbidity and mortality that increases with each unit of blood received. Clinical trials consistently support a conservative over a liberal approach to transfusion. Yet there remains wide variation in practice, and more than half of red cell transfusions may be inappropriate. Adopting a more comprehensive approach to the bleeding, coagulopathic, or anemic patient has the potential to improve patient care.

METHODS

We present a patient-centered blood management (PBM) paradigm. The 4 guiding principles of effective PBM that we present include anemia management, coagulation optimization, blood conservation, and patient-centered decision making.

RESULTS

PBM has the potential to decrease transfusion rates, decrease practice variation, and improve patient outcomes.

CONCLUSION

PBM's value proposition is highly aligned with that of hospital medicine. Hospitalists' dual role as front-line care providers and quality improvement leaders make them the ideal candidates to develop, implement, and practice PBM.

Patient-centered approach to ensuring appropriateness of care through blood management

BACKGROUND

Concerns have been raised about the safety and efficacy of blood transfusions. Blood products are in demand and a decreasing supply is projected, with resource conservation a global concern. A consultant group determined that the transfusion rate at Mease Countryside Hospital was higher than an average baseline.

METHODS

A process-improvement project was initiated using a multidisciplinary team approach to improve blood utilization and ensure appropriateness in transfusion practice. The foundation of this project was to create new guidelines for transfusion; provide detailed education, communication, reporting, and feedback; and develop criteria to ensure compliance.

RESULTS

The mean monthly usage of red blood cell units per 1000 inpatient discharges between April 2010 and October 2011 was 321.4 compared with 212.0 for the 5 months after implementation. The mean monthly number of patients transfused per 1000 inpatient discharges from April 2010 to October 2011 was 135.2 compared with 90.2 after implementation. In both cases, this reduction was found to be statistically significant at a 95% confidence level (P = 0.000 in both respects).

CONCLUSIONS

The success of this project was the result of careful planning and execution, administrative support, physician leadership, and teamwork. Blood management includes strategies to avoid inappropriate transfusions and proactively treat anemia. Anemia management should be based on the patient's symptoms, laboratory values, and clinical assessment. Treatment of anemia should encompass a patient-centered approach, with the aim of promoting patient safety and minimizing the risk from exposure to blood products.

Incidence and costs of bleeding-related complications in French hospitals following surgery for various diagnoses

Background

Limited information is available on the epidemiology and economics of bleeding during surgery in France.

Method

The objective of this study was to examine the incidence, costs and length of stay (LOS) of bleeding-related complications during various surgical procedures.

A retrospective DRG (diagnosis-related group) analysis was conducted using the French National database PMSI (Programme Médicalisé des Systèmes d’Informations). Patients undergoing surgery during 2008 were identified according to their DRG classifications and those with at least one episode of secondary haemostasis and blood transfusion (according to French procedure codes) were designated as ‘with bleeding’ (WB). The analysis focussed on DRGs where ≥10% of patients presenting with bleeding and compared them to patients who did not require blood transfusions (i.e. without bleeding: WoB).

Hospital LOS and costs (age and gender adjusted) were compared between WB and WoB patients within each DRG. Hospitalisation periods exceeding the LOS average (derived from the PMSI database) were compared using multivariate logistic regression adjusted for patient characteristics.

Results

Amongst all 88 different surgical DRGs recognised by the French database 24 (totalling 321,657 hospitalisations) yielded WB rates ≥10% (range 10.3–25.3%). The highest DRG rates were for transplantations, cardiac and major orthopaedic surgery, vascular and solid organ surgery.

The average LOS for the WB population (adjusted for age, gender, number of procedures and secondary diagnoses) were 3.38 days (26.5%) longer than for the WoB population (p < 0.001). The average adjusted LOS costs for a WB patient were estimated at €12,087, and for a WoB patient €10,086 i.e. 19.9% higher than for WB patients (p < 0.001). The overall mean LOS was exceeded by 42.3% of WB patients compared to 37.0% of WoB patients (p < 0.001). Also, WB patients were more likely to exceed the average LOS than were WoB patients (Odds Ratio (OR) = 1.09, p < 0.001), after adjusting for patient characteristics.

Conclusions

The present study for France demonstrates a significant increase of hospital LOS and associated costs following post-surgical bleeding, supporting the need for blood conservation strategies.

Optimizing hemostatic practices: matching the appropriate hemostat to the clinical situation

Achieving hemostasis is a critical focus of clinicians working in the surgical setting, given that uncontrolled surgical bleeding is associated with increased mortality rates and higher costs of care. As principal members of the surgical team, perioperative nurses are in an optimal position to plan and direct care during a bleeding event and throughout a patient's surgical stay. This supplement includes an assessment of the clinical and economic effects of surgical bleeding, a thorough review of available therapies, and a detailed comparison of these products to demonstrate which agents are best suited for a given clinical situation. By understanding the basic science of coagulation and hemostasis and current advances in topical hemostatic agents, including their safety, efficacy, and judicious use, perioperative nurses will be empowered to better assist the surgeon in optimizing patient outcomes.

Applying principles of formulary management to blood banking

The pharmacy and therapeutics (P&T) committee or its equivalent has been a long-standing committee of the medical staff in almost every institution. The P&T committee is typically defined as the body that recommends policy to the medical staff and the administration of the organization on matters related to the safe and therapeutic use of medications as well as other matters relating to medication use. The Food and Drug Administration definition of a drug includes blood and blood components, and the American Society of Health-System Pharmacists guidelines suggest including blood derivatives in their definition of a drug. Clinicians and other health care providers have needed to become more familiar with blood and blood component therapy as more prescription blood products have become available. As such, the P&T committee could work collaboratively with blood bank personnel, who are experts in this area, to help ensure that blood derivative products undergo the same evidence-based formulary review process as other medications.

Achieving hemostasis with topical hemostats: making clinically and economically appropriate decisions in the surgical and trauma settings

Achieving hemostasis is a crucial focus of clinicians working in surgical and trauma settings. Topical hemostatic agents-including mechanical hemostats, active hemostats, flowable hemostats, and fibrin sealants-are frequently used in efforts to control bleeding, and new options such as hemostatic dressings, initially used in combat situations, are increasingly being used in civilian settings. To achieve successful hemostasis, a number of vital factors must be considered by surgeons and perioperative nurses, such as the size of the wound; bleeding severity; and the efficacy, possible adverse effects, and method of application of potential hemostatic agents. Understanding how and when to use each of the available hemostatic agents can greatly affect clinical outcomes and help to limit the overall cost of treatment.

Is resternotomy in cardiac surgery still a problem?

Multiple factors contribute to the growing number of reoperations for congenital and acquired cardiovascular diseases in the United States. Although the hazards are well-recognized, the health economic burden of resternotomy (RS) remains unclear and may be difficult to quantify. Contrary to published studies citing low frequencies of catastrophic hemorrhage and mortality, survey responses from practicing surgeons disclose higher rates of complications. Safety strategies in cardiac reoperation have generally involved efforts to maximize visualization during dissection, specialized surgical maneuvers and instrumentation, customized methods for establishing extracorporeal circulation, and techniques to prevent or avoid retrosternal adhesions. Yet, the relative cost-effectiveness of these strategies is largely unexplored. With the ongoing constraints in healthcare budgets, differentiating the value of existing and future approaches in terms of relative clinical benefits, costs, and impact on resource utilization will become increasingly important. We reviewed the relevant published literature in order to survey the morbidity and resource utilization associated with RS in cardiac reoperation and to identify key issues relevant for future studies.

Hemostatic effectiveness of Fibrin pad after partial nephrectomy in swine

BACKGROUND

Current management of severe surgical or traumatic bleeding is often achieved by manual tamponade or occlusion using devices such as tourniquets or ligatures. There are some clinical scenarios where these options are either marginally effective or impractical. The present study evaluates a new combination device (Fibrin pad) consisting of biologically active components (human thrombin and fibrinogen) delivered to the targeted site by an absorbable synthetic matrix (oxidized regenerated cellulose and polyglactin 910) in a swine severe bleeding model. In this model, severe bleeding can be managed by concurrent use of several currently available treatments, or a more convenient option that offers performance and safety advantages.

MATERIALS AND METHODS

Partial nephrectomies were performed on swine and treated with either Fibrin pad (FP) or conventional therapy (CTR)-temporary occlusion of renal artery, electrocautery, SURGIFLO, EVITHROM, SURGICEL NU-KNIT, and PDS II suture). After intraoperative hemostasis was confirmed, the animals were closed and recovered, then survived for 2, 14, or 56 d.

RESULTS

Hemostasis was achieved at surgery and maintained in all FP and CTR treated animals. FP was as effective as CTR at establishing durable hemostasis. Treatment with FP did not require temporary occlusion of the renal artery and decreased the total treatment time by half. No animals in either group had complications related to postoperative bleeding at any time during the study. There was no evidence of pulmonary thrombi or evidence of thrombotic complications. No biologically significant adverse local tissue response was present in association with the Fibrin pad at any study interval, and no biologically relevant or consistent changes in blood parameters were identified.

CONCLUSIONS

Fibrin pad was as effective as CTR for the primary management of severe bleeding without occlusion of the renal artery and a shorter surgical time. No evidence of a systemic or local adverse response was identified due to exposure to the Fibrin pad.

Achieving hemostasis in the surgical field

Hemostatic mechanisms are an integral part of the human physiology. Traditionally divided into intrinsic and extrinsic arms, the coagulation cascade converges, through the interactions of many different factors, at a common element-thrombin. As a consequence, a number of different agents have been developed to supplement this common, critical step to aid surgical hemostasis. Intraoperative interventions most commonly include sutures and heat-generating cautery devices; however, these methods are sometimes insufficient or inappropriate for a specific procedure or anatomic location, leading to the development of other adjunctive therapies, including topical hemostats. Topical hemostatic agents generally act as active, passive, and combinations therapies, depending on their individual composition and mode of action. We provide a brief review of the normal coagulation cascade, including critical points, followed by a discussion of surgical strategies and adjuctive therapies used to achieve surgical hemostasis and concluding with a discussion of topical thrombins.

Risk assessment and cost-effectiveness/utility analysis

Decision-makers at all levels of public health and transfusion medicine have always assessed the risks and benefits of their decisions. Decisions are usually guided by immediately available information and a significant amount of experience and judgment. For decisions concerning familiar situations and common problems, judgment and experience may work quite well, but this type of decision process can lack clarity and accountability. Public health challenges are changing as emerging diseases and expensive technologies complicate the decision-makers' task, confronting the decision-maker with new problems that include multiple potential solutions. Decisions regarding policies and adoption of technologies are particularly complex in transfusion medicine due to the scope of the field, implications for public health, and legal, regulatory and public expectations regarding blood safety. To assist decision-makers, quantitative risk assessment and cost-effectiveness analysis are now being more widely applied. This set of articles will introduce risk assessment and cost-effectiveness methodologies and discuss recent applications of these methods in transfusion medicine.