Pharmacologic Interventions for the Management of Critical Bleeding

Fixed-Dose Factor Eight Inhibitor Bypassing Activity (FEIBA) in the Management of Warfarin-Associated Coagulopathies

This retrospective review evaluated our institutions’ practice of administering low fixed-dose FEIBA (high (1000 units) or low dose (500 units) for an INR ≥ 5 or <5, respectively) for the management of warfarin-associated coagulopathies. The primary outcome was the percentage of patients who had a post-FEIBA INR ≤ 1.5. In the total population, 55.6% (10/18) of patients achieved a post-FEIBA INR ≤ 1.5. In the subgroup analysis, significantly more patients in the low dose FEIBA group achieved a post-FEIBA INR ≤ 1.5 compared to the high dose FEIBA group (71.4% vs. 45.5%, respectively, p < 0.001). In the post hoc analysis, there was a significant difference in the number of patients who achieved a post-FEIBA INR ≤ 1.5 when comparing those who received high dose FEIBA with a baseline INR 5−9.9 to those who received high dose FEIBA with a baseline INR ≥ 10 (60% vs. 33.3%, respectively, p < 0.001). The existing literature and our findings suggest that patients who present with lower baseline INR values and receive additional reversal agents are more likely to meet post-reversal INR goals. Current low fixed-dose protocols may be oversimplified and may need to be revised to provide larger fixed-doses.

Calculating and selecting fluid therapy and blood product replacements for horses with acute hemorrhage

BACKGROUND

Blood products, crystalloids, and colloid fluids are used in the medical treatment of severe hemorrhage in horses with a goal of providing sufficient blood flow and oxygen delivery to vital organs. The fluid treatments for hemorrhage will vary depending upon severity and duration and whether hemorrhage is controlled or uncontrolled.

DESCRIPTION

With acute and severe controlled hemorrhage, treatment is focused on rapidly increasing perfusion pressure and blood flow to vital organs. This can most easily be accomplished in field cases by the administration of hypertonic saline. If isotonic crystalloids are used for resuscitation, the volume administered should be at least as great as the estimated blood loss. Following crystalloid resuscitation, clinical signs, HCT, and laboratory evidence of tissue hypoxia may help determine the need for a whole blood transfusion. In uncontrolled hemorrhage, crystalloid resuscitation is often more conservative and is referred to as "permissive hypotension." The goal of "permissive hypotension" would be to provide enough perfusion pressure to vital organs such that function is maintained while keeping blood pressure below the normal range in the hope that clot formation will not be disrupted. Whole blood and fresh frozen plasma in addition to aminocaproic acid are indicated in most horses with severe uncontrolled hemorrhage.

SUMMARY

Blood transfusion is a life-saving treatment for severe hemorrhage in horses. No precise HCT serves as a transfusion trigger; however, an HCT < 15%, lack of appropriate clinical response, or significant improvement in plasma lactate following crystalloid resuscitation and loss of 25% or more of blood volume is suggestive of the need for whole blood transfusion. Mathematical formulas may be used to estimate the amount of blood required for transfusion following severe but controlled hemorrhage, but these are not very accurate and, in practice, transfusion volume should be approximately 40% of estimated blood loss.

KEY POINTS

Modest hemorrhage, <15% of blood volume (<12 mL/kg), can be fully compensated by physiological mechanisms and generally does not require fluid or blood product therapy. More severe hemorrhage, >25% of blood volume (> 20 mL/kg), often requires crystalloid or blood product replacement, while acute loss of greater than 30% (>24 mL/kg) of blood volume may result in hemorrhagic shock requiring resuscitation treatments Uncontrolled hemorrhage is a common occurrence in equine practice, and is most commonly associated with abdominal bleeding (eg, uterine artery rupture in mares). If the hemorrhage can be controlled such as by ligation of a bleeding vessel, then initial efforts to resuscitate the horse should focus on increasing perfusion pressure and blood flow to organs as quickly as possible with crystalloids or colloids while assessing need for whole blood transfusion. While fluid therapy is being administered every effort to physically control hemorrhage should be made using ligatures, application of compression, surgical methods, and local hemostatic agents like collagen-, gelatin-, and cellulose-based products, fibrin, yunnan baiyao (YB), and synthetic glues Although some synthetic colloids have been shown to be associated with acute kidney injury in people receiving resuscitation therapy,²⁰ this undesirable effect in horses has not been reported.

Health and economic outcomes associated with uncontrolled surgical bleeding: a retrospective analysis of the Premier Perspectives Database

Background

Bleeding remains a common occurrence in surgery. Data describing the burden of difficult-to-control bleeding and topical absorbable hemostat use are sparse. This study was conducted to estimate the clinical and economic impact that remains associated with uncontrolled surgical bleeding, even when hemostats are used during surgery.

Methods

This US retrospective analysis used the Premier Perspectives Database. Hospital discharges from 2012 were used to identify patients treated with hemostats during eight surgery types. Patients were included if they were ≥18 years, had an inpatient hospitalization with one of the eight surgeries, and received a hemostat on the day of surgery. Patients were stratified by procedure and presence or absence of major bleeding (uncontrolled) despite hemostat use. Outcomes were all-cause hospitalization costs, hemostat costs, length of stay, reoperation, and surgery-related complications (eg, mortality). Statistical significance was tested through chi-square or t-tests. Multivariate analyses were conducted for all-cause costs and length of stay using analysis of covariance.

Results

Among 25,048 procedures, major bleeding events occurred in 14,251 cases. Despite treatment with hemostats, major bleeding occurred in 32%–68% of cases. All-cause costs were significantly higher in patients with uncontrolled bleeding despite hemostat use versus controlled bleeding (US$24,203–$61,323 [uncontrolled], US$14,420–$45,593 [controlled]; P<0.001). Hemostat costs were significantly greater in the uncontrolled bleeding cohort for all surgery types except cystectomy and pancreatic surgery. Reoperation and mortality rates were significantly higher in the uncontrolled bleeding cohort in all surgical procedures except cystectomy and radical hysterectomy.

Conclusion

Uncontrolled intraoperative bleeding despite hemostat use is prevalent and associated with significantly higher hospital costs and worse clinical outcomes across several surgical procedures compared to controlled bleeding. There is an unmet need for newer hemostats that can more effectively control bleeding, improve outcomes, and reduce hospital resource use.

Confronting the chronically anticoagulated, acute care surgery patient as we evolve into the post-warfarin era

There are a growing number of new anticoagulants used as an alternative to warfarin. Surgeons will be confronted with an increasing number of patients who may be on these outpatient medications and must be familiar with their management strategies. The purpose of this review is to examine the mechanisms, monitoring and therapeutic reversal of the non-warfarin antithrombotic agents now so frequently confronting the acute care surgeon.

Adverse drug events associated with disorders of coagulation

Disorders of coagulation are common adverse drug events encountered in critically ill patients and present a serious concern for intensive care unit (ICU) clinicians. Dosing strategies for medications used in the ICU are typically developed for use in noncritically ill patients and, therefore, do not account for the altered pharmacokinetic and pharmacodynamic properties encountered in the critically ill as well as the increased potential for drug-drug interactions, given the far greater number of medications ordered. This substantially increases the risk for coagulation-related adverse reactions, such as a bleeding or prothrombotic events. Although many medications used in the ICU have the potential to cause coagulation disorders, the exact incidence will vary based on the specific medication, dose, concomitant drug therapy, ICU setting, and patient-specific comorbidities. Clinicians must strongly consider these factors when evaluating the risk/benefit ratio for a particular therapy. This review surveys recent literature documenting the risk for adverse drug reactions specific to bleeding and/or clotting with commonly used medications in the ICU.

The role of recombinant-activated factor VII in bleeding trauma patients

PURPOSE OF REVIEW

Exsanguinating hemorrhage and postshock organ failure account for 35-40% of deaths from trauma, and there is an increasing recognition of the importance of coagulopathy in the evolution of this disease.

RECENT FINDINGS

Since 1999, case reports, small series, retrospective studies and a few controlled trials have reported the use of recombinant-activated factor VII (rFVIIa) as an adjunct for reversal of coagulopathy in trauma patients, and numerous other publications have examined the use of rFVIIa in related conditions such as traumatic brain injury, hemorrhagic stroke and uncontrolled surgical bleeding.

SUMMARY

We present a brief discussion of the mechanism of action of rFVIIa and its role in facilitating hemostasis and a review of the recent medical literature on the use of rFVIIa in trauma patients, including current guidelines and controversies.

Blood conservation in practice: an overview

Allogeneic blood transfusions are associated with risks and unfavourable outcomes. Blood conservation provides an alternative, with potential to improve patient care with limited or no blood transfusion. Many approaches are available, but the most essential ones are simple and cost free.

Pediatric off-label use of recombinant factor VIIa

OBJECTIVE

Our goal was to report our institutional experience with recombinant factor VIIa for the treatment and/or prevention of bleeding in nonhemophiliac children.

METHODS

This was a retrospective case series in a tertiary pediatric referral hospital.

RESULTS

During 1999-2006, 135 patients received recombinant factor VIIa for off-label use. The median number of doses was 2; the median dose was 88 mug/kg. The most common diagnoses among patients receiving recombinant factor VIIa were disseminated intravascular coagulation/sepsis (28), surgical bleeding (19), procedural prophylaxis (16), and trauma (15). The median volume of blood products administered 24 hours before recombinant factor VIIa treatment was 29.7 vs 11.7 mL/kg 24 hours after treatment. Only 1 high-risk patient had significant bleeding after receiving prophylactic recombinant factor VIIa before an invasive procedure. Nonsurvivors had significantly increased incidence of multiple organ dysfunction syndrome (75%) compared with survivors (23%). The largest group of patients (n = 28) received recombinant factor VIIa for bleeding and/or coagulopathy because of disseminated intravascular coagulation; the mortality in this group was 26 (93%) of 28. Eleven patients received multiple doses of recombinant factor VIIa to treat bleeding complications after hematopoietic stem cell transplant, without improvement in blood use. Mortality in medical patients was 58% vs 16% in surgical patients. Three patients had significant thrombotic adverse events after receiving recombinant factor VIIa, resulting in 2 deaths and 1 leg amputation.

CONCLUSIONS

Off-label use of recombinant factor VIIa significantly decreases blood-product administration; surgical patients had control of life-threatening bleeding with low associated mortality. Prophylactic recombinant factor VIIa may be effective in preventing bleeding if given before invasive procedures in children at high risk. Prolonged use of recombinant factor VIIa for bleeding complications after hematopoietic stem cell transplant is not effective in preventing packed red blood cell transfusion. Presence of disseminated intravascular coagulation and mulitorgan dysfunction syndrome may help predict futility of recombinant factor VIIa treatment. Off-label use of recombinant factor VIIa is associated with thromboembolic events in children.

Goals of Therapy in Common Bleeding Emergencies

Acute hemorrhage is a medical emergency requiring immediate attention, regardless of whether it manifests as blood volume lost and inadequate oxygen delivery, or as a pathologic space-occupying lesion capable of exerting elevated organ-damaging pressures. The most commonly encountered and challenging hemorrhagic emergencies to manage include bleeding secondary to traumatic injury, intracranial hemorrhage, severe gastrointestinal bleeding, and diffuse intraoperative bleeding. The critical steps taken to locate, assess, and arrest bleeding in each of these circumstances can take various paths. For all of them, the basic principles of treatment are the same: identify and correct the anatomic source and restore normal hemostatic function. The agents used to accomplish these goals, however, may differ. Several typical clinical scenarios and the evidence-based approaches used to manage such cases are presented.