Hemostatic drugs

The impact of aprotinin on renal function after liver transplantation: an analysis of 1,043 patients

Renal dysfunction is frequently seen after orthotopic liver transplantation (OLT). Aprotinin is an antifibrinolytic drug which reduces blood loss during OLT. Recent studies in cardiac surgery suggested a higher risk of postoperative renal complications when aprotinin is used. The impact of aprotinin on renal function after OLT, however, is unknown. In 1,043 adults undergoing OLT, we compared postoperative renal function in patients who received aprotinin (n = 653) or not (n = 390). Using propensity score stratification (C-index 0.82) and multivariate regression analysis, aprotinin was identified as a risk factor for severe renal dysfunction within the first week, defined as increase in serum creatinine by >or= 100% (OR = 1.97, 95% CI = 1.14-3.39; p = 0.02). No differences in renal function were noted at 30 and 365 days postoperatively. Moreover, no significant differences were found in the need for renal replacement therapy (OR = 1.52, 95% CI = 0.94-2.46; p = 0.11) or in 1-year patient survival rate (OR = 1.14, 95% CI = 0.73-1.77; p = 0.64) in patients who received aprotinin or not. In conclusion, aprotinin is associated with a higher risk of transient renal dysfunction in the first week after OLT, but not with a higher need for postoperative renal replacement therapy or an increased risk of mortality.

Tranexamic acid diminishes intraoperative blood loss and transfusion in spinal fusions for duchenne muscular dystrophy scoliosis

STUDY DESIGN

Retrospective review of intraoperative blood loss and blood replacement.

OBJECTIVE

We compared intraoperative blood loss and blood replacement during spinal fusion surgery for scoliosis in Duchenne muscular dystrophy (DMD) performed with and without the synthetic antifibrinolytic agent tranexamic acid (TXA).

SUMMARY OF BACKGROUND DATA

High levels of intraoperative blood loss are widely documented in DMD patients undergoing posterior spinal fusion for scoliosis. The effect of the antifibrinolytic agent tranexamic acid on decreasing the blood loss has not been studied in a large group of DMD patients.

METHODS

All 56 DMD patients underwent posterior spinal fusion with the same technique using 2 rods and multiple sublaminar wires. TXA was not used in 36 patients and was used in 20. In the respective groups, the age at surgery (14 vs. 13.9 years), the preoperative deformity (45 degrees vs. 51 degrees ), the mean number of levels fused (14.3 vs. 14.7), and the mean surgical times (446 minutes vs. 459 minutes) were similar. TXA dose was 100 mg/kg in solution over 15 minutes before incision followed by an infusion of 10 mg/kg per hour during surgery. Standardized measurements of intraoperative blood loss were used and calculated to compare total amount of blood loss in milliliters per patient and blood loss as a percentage in relation to estimated blood volume [estimated blood loss (EBL)/estimated blood volume (EBV) x 100]. The EBV was calculated to be 70 mL/kg (body weight).

RESULTS

Mean blood loss with TXA was 1944 +/- 789 mL (range, 760-4000 mL) and without TXA was 3382 +/- 1795 mL (range, 600-9580 mL) (P < 0.001). Blood loss with TXA decreased by 42% compared with those not treated with TXA. Accounting for patient weight and estimated blood volume, mean % blood loss with and without TXA was 47% +/- 28% versus 112% +/- 67% (P < 0.001). This physiologic indicator shows that blood loss with TXA decreased by 58% compared with those patients not treated with TXA. TXA was also found to reduce blood loss after accounting for surgical time. No hypercoagulation or other complications from TXA therapy were observed. The reduced blood loss in TXA-treated patients translated into decreased blood transfusions. Transfusion of homologous whole blood and packed red blood cells in the TXA group was decreased by 46% compared with the no TXA group (mean levels, 512 +/- 470 mL vs. 955 +/- 718 mL), and transfusion of autologous cell saver blood was decreased by 42% in the TXA group (mean levels, 419 +/- 235 mL vs. 728 +/- 416 mL).

CONCLUSION

TXA significantly reduces both intraoperative blood loss and the need for homologous transfusion of whole blood and packed red blood cells in DMD patients undergoing posterior spinal fusion for scoliosis.

Use of aprotinin in extrapleural pneumonectomy: effect on hemostasis and incidence of complications

BACKGROUND

The purpose of this study was to examine the effect of aprotinin on blood loss in extrapleural pneumonectomy and to identify potential treatment-related complications.

METHODS

Between March 1, 1999, and July 1, 2004, 27 (52%) of 52 patients who underwent extrapleural pneumonectomy received half-dose aprotinin (1 million kallikrein inhibition units load; 250,000 kallikrein inhibition units per hour infusion). A retrospective data review and analysis were performed.

RESULTS

The mean age was 59.8 +/- 11 years, and 45 of 52 patients (87%) were male. Indications for extrapleural pneumonectomy were malignant pleural mesothelioma (n = 50) and pleural-based sarcoma (n = 2). The administration of aprotinin had no significant effect on intraoperative blood loss (1,010 +/- 599 versus 1,182 +/- 688 mL; p = 0.34) or units of packed red blood cells transfused intraoperatively (2.0 +/- 1.7 versus 1.9 +/- 1.7 units; p = 0.86). None of the patients who received aprotinin required the use of non-packed red blood cells blood products, but 4 patients (16%) who did not receive aprotinin required such transfusion (p < 0.05). Postoperative chest tube output at 12 and 24 hours was lower in the aprotinin group (381 +/- 195 and 867 +/- 313 mL, respectively) compared with the control group (725 +/- 527 and 1,221 +/- 442 mL, respectively; p < 0.03). There was no significant difference in incidence of postoperative thromboembolic events between the aprotinin and the control group (5 versus 4 patients; p = 1.0), and 2 patients in each group experienced renal insufficiency (p = 1.0).

CONCLUSIONS

Half-dose aprotinin did not decrease intraoperative blood loss or packed red blood cells transfusion in extrapleural pneumonectomy. However, use of aprotinin was associated with decreased use of non-packed red blood cells blood products and lower postoperative chest tube output. Aprotinin administration was not associated with an increase in incidence of postoperative complications.

Pharmacologic Interventions for the Management of Critical Bleeding

Hospital pharmacists are often consulted for their knowledge about coagulation and therapeutic interventions for the management of critical bleeding. Many pharmacotherapies are available for this purpose, both systemic and topical, and others are in development. These agents and their mechanisms of action are reviewed, and perspectives are provided regarding their use in various clinical settings. Also provided are associated precautions to promote safe use. Current controversies surrounding pharmacotherapeutic agents used to control serious bleeding (e.g., in various types of surgery, trauma, obstetrics, and intracranial hemorrhage) are also discussed.

Hepatic veno-occlusive disease after tranexamic acid administration in patients undergoing allogeneic hematopoietic stem cell transplantation

Tranexamic acid is one of the widely used antifibrinolytic agents. In spite of its effective inhibitory activity against plasminogen, thromboembolic adverse events caused by tranexamic acid are rare. We encountered three recipients of allogeneic hematopoietic stem cell transplantation (HSCT) who developed hepatic veno-occlusive disease (VOD) shortly after the administration of tranexamic acid. Hepatic VOD was resolved completely in all patients with the discontinuation of the drug, and with supportive measures with or without intravenous tissue plasminogen activator administration. These findings suggest that administration of tranexamic acid could be one of the possible risk factors for developing hepatic VOD in HSCT recipients.

Pharmacokinetics and pharmacodynamics of ε-aminocaproic acid in horses

OBJECTIVE

To determine the pharmacokinetics and pharmacodynamics of epsilon-aminocaproic acid (EACA), including the effects of EACA on coagulation and fibrinolysis in healthy horses.

ANIMALS

6 adult horses.

PROCEDURES

Each horse received 3.5 mg of EACA/kg/min for 20 minutes, i.v. Plasma EACA concentration was measured before (time 0), during, and after infusion. Coagulation variables and plasma alpha(2)-antiplasmin activity were evaluated at time 0 and 4 hours after infusion; viscoelastic properties of clot formation were assessed at time 0 and 0.5, 1, and 4 hours after infusion. Plasma concentration versus time data were evaluated by use of a pharmacokinetic analysis computer program.

RESULTS

Drug disposition was best described by a 2-compartment model with a rapid distribution phase, an elimination half-life of 2.3 hours, and mean residence time of 2.5 +/- 0.5 hours. Peak plasma EACA concentration was 462.9 +/- 70.1 microg/mL; after the end of the infusion, EACA concentration remained greater than the proposed therapeutic concentration (130 microg/mL) for 1 hour. Compared with findings at 0 minutes, EACA administration resulted in no significant change in plasma alpha(2)-antiplasmin activity at 1 or 4 hours after infusion. Thirty minutes after infusion, platelet function was significantly different from that at time 0 and 1 and 4 hours after infusion. The continuous rate infusion that would maintain proposed therapeutic plasma concentrations of EACA was predicted (ie, 3.5 mg/kg/min for 15 minutes, then 0.25 mg/kg/min).

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that EACA has potential clinical use in horses for which improved clot maintenance is desired.

Influence of calcium chloride and aprotinin in the in vivo biological performance of a composite combining biphasic calcium phosphate granules and fibrin sealant

Highly bioactive biomaterials have been developed to replace bone grafts in orthopedic revision and maxillofacial surgery for bone augmentation. A mouldable, self-hardening material can be obtained by combining TricOs Biphasic Calcium Phosphate Granules and Tissucol Fibrin Sealant. Two components, calcium chloride and antifibrinolytic agents (aprotinin), are essential for the stability of the fibrin clot. The ingrowth of cells in composites combining sealants without calcium chloride or with a low concentration of aprotinin was evaluated in vivo in an experiment on rabbits. Bone colonization was compared using TricOs alone or with the composite made from TricOs and the standard fibrin sealant. Without the addition of calcium chloride, the calcium ions released by the ceramic component interacted with the components of the sealant too late to stabilize the clot. With a low concentration of aprotinin, the degradation of the clot occurred more quickly, leading to the absence of a scaffold on which the bone cells could colonize the composite. Our results indicate that a stable fibrin scaffold is crucial for bone colonization. The low calcium chloride and low aprotinin groups have shown lower bone growth. Further studies will be necessary to determine the minimal amount of antifibrinolytic agent (aprotinin) necessary to allow the same level of osteogenic activity as the TricOs-fibrin glue composite.

The use of desmopressin as a hemostatic agent: a concise review

Desmopressin, a synthetic derivative of the antidiuretic hormone vasopressin, is the treatment of choice for most patients with von Willebrand disease and mild hemophilia A. Moreover, the compound has been shown to be useful in a variety of inherited and acquired hemorrhagic conditions, including some congenital platelet function defects, chronic liver disease, uremia, and hemostatic defects induced by the therapeutic use of antithrombotic drugs such as aspirin and ticlopidine. Finally, desmopressin has been used as a blood saving agent in patients undergoing operations characterized by large blood loss and transfusion requirements, but studies suggest that this is not as effective as other methods. This review briefly summarizes the current clinical indications on the use of desmopressin as a hemostatic agent.

Reducing the risk of ICH enlargement

Intracerebral hemorrhage (ICH) comprises 15% of all strokes, and carries the highest risk of mortality and poor long-term outcome. ICH has long been recognized as the least treatable form of stroke, and hematoma volume as the strongest single predictor of mortality and outcome. CT-based studies have found that early substantial hematoma expansion occurs in 18-38% of patients initially scanned within 3 h of symptom onset. This finding is associated with early neurological deterioration and an increased risk of poor outcome. Ultra-early hemostatic therapy might be beneficial in preventing hematoma growth, resulting in improved mortality and neurological function. Recombinant activated factor VII (rFVIIa) promotes local hemostasis in the presence or absence of coagulopathy at sites of vascular injury, and is a promising treatment for arresting active bleeding in ICH. The safety and feasibility of this approach was confirmed in a phase IIb randomized, double-blind, placebo-controlled, dose-ranging trial of 399 patients with non-coagulopathic ICH. Administration of rFVIIa within 4 h of ICH onset resulted in a significant reduction of hematoma expansion at 24 h, and reduced mortality and improved functional outcome at 90 days. A confirmatory phase III trial (The FAST Trial) to confirm these results will complete enrollment in the end of 2006.

Simple, rapid, and sensitive liquid chromatography-fluorescence method for the quantification of tranexamic acid in blood

Tranexamic acid (TA) is a synthetic antifibrinolytic agent that is being considered as a candidate adjuvant drug for site-specific pharmaco-laser therapy of port wine stains. For drug utility studies, a high-performance liquid chromatography (HPLC)-fluorescence method was developed for the quantification of TA in blood. Platelet-poor plasma was prepared, size-separated using 3kDa cut-off centrifuge filters, and derivatized with naphthalene-2-3-dicarboxaldehyde (NDA) and cyanide. The excess of NDA was quenched after 2 min by adding tryptophan. The derivatives were separated on a 2.1mm C18 column using an acetate buffer/acetonitrile gradient. Excellent separation from plasma background was obtained at pH 5.5. Quantification was carried out at 440/520 nm. The limit of detection was 0.5 microM and the mean+/-SD recovery from whole blood was 81.7+/-10.9%. Derivatized TA samples were stable for at least 36 h at 4 degrees C. The method was successfully applied to a heat-induced TA release study from thermosensitive liposomes.

Use of blood and blood products in trauma

According to the global study of the burden of disease, violence and accidental injury account for 12% of deaths worldwide; 30-40% of trauma mortality is attributable to haemorrhage. The highly complex haemostatic system is severely impaired as a result of haemorrhagic shock, acidosis, hypothermia, haemodilution, hyperfibrinolysis, and consumption of clotting factors. Thus it is important to prioritize the prevention of the development of coagulopathy. Timely transfusion of red blood cells and plasma products becomes essential to restore tissue oxygenation, support perfusion, and maintain the pool of active haemostatic factors. The limits to this strategy to compensate for the loss of blood and coagulation factors are discussed. In the absence of international guidelines, there is an ongoing debate about a generally accepted treatment algorithm, mass transfusion protocols, and adverse events that have been observed as a result of transfusion. Thus many recommendations are based upon expert opinion rather than on evidence. In this chapter we address key issues of transfusions of red blood cells and plasma products in the acute control of bleeding in traumatized patients.

Dental health status of liver transplant candidates

A prerequisite dental evaluation is usually recommended for potential organ transplant candidates. This is based on the premise that untreated dental disease may pose a risk for infection and sepsis, although there is no evidence that this has occurred in organ transplant candidates or recipients. The purpose of this study was to assess the prevalence of dental disease and oral health behaviors in a sample of liver transplant candidates (LTCs). Oral examinations were conducted on 300 LTCs for the presence of gingivitis, dental plaque, dental caries, periodontal disease, edentulism, and xerostomia. The prevalence of these conditions was compared with oral health data from national health surveys and examined for possible associations with most recent dental visit, smoking, and type of liver disease. Significant risk factors for plaque-related gingivitis included intervals of more than 1 yr since the last dental visit (P = 0.004), smoking (P = 0.03), and diuretic therapy (P = 0.005). Dental caries and periodontal disease were also significantly associated with intervals of more than 1 yr since the last dental visit (P = 0.004). LTCs with viral hepatitis or alcoholic cirrhosis had the highest smoking rate (78.8%). Higher rates of edentulism occurred among older LTCs who were less likely to have had a recent dental evaluation (mean 88 months). In conclusion, intervals of more than 1 yr since the last dental visit, smoking, and diuretic therapy appear to be the most significant determinants of dental disease and the need for a pretransplantation dental screening evaluation in LTCs. Edentulous patients should have periodic examinations for oral cancer.

Recombinant Activated Factor VII for Acute Intracerebral Hemorrhage

Intracerebral hemorrhage is the least treatable form of stroke and is associated with 30% to 50% mortality rate. Early hematoma growth occurs in 18% to 38% of patients scanned within 3 hours of intracerebral hemorrhage onset, and hematoma volume is an important predictor of poor outcome. Recombinant activated factor VII, a potent initiator of hemostasis, is currently approved for the treatment of bleeding in hemophilia patients with inhibitors and has also been shown to promote hemostasis in patients with normal coagulation. A recent phase IIB randomized, double-blind, placebo-controlled, dose-ranging “proof-of-concept” trial enrolled 399 intracerebral hemorrhage patients to determine whether recombinant activated factor VII can limit ongoing bleeding and improve outcome. An approximate 50% relative reduction in hematoma growth was evident with all 3 doses that were tested (40, 80, and 160 μg/kg), which translated into an average reduction in absolute intracerebral hemorrhage volume growth of ≈5 milliliters. More importantly, recombinant activated factor VII was associated with a 38% relative reduction in mortality and significantly improved functional outcome among survivors, despite a 5% frequency of arterial thromboembolic events (primarily ischemic stroke and myocardial infarction). A large phase III trial (the FAST trial [ F actor Seven for A cute Hemorrhagic S troke T reatment]) is now in progress to confirm these findings.

Antifibrinolytic amino acids for acquired coagulation disorders in patients with liver disease

BACKGROUND

Upper gastrointestinal bleeding is one of the most frequent causes of morbidity and mortality in the course of liver cirrhosis. Patients with liver disease frequently have haemostatic abnormalities, which include accelerated fibrinolysis. Several primary treatments are used for upper gastrointestinal bleeding in patients with liver diseases. Supplementary interventions are often used as well. One of them could be antifibrinolytic amino acids administration.

OBJECTIVES

To assess the beneficial and harmful effects of antifibrinolytic amino acids for upper gastrointestinal bleeding in patients with acute or chronic liver disease plus acquired coagulation disorders.

SEARCH STRATEGY

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (Issue 1, 2006), MEDLINE (1950 to March 2006), EMBASE (1980 to March 2006), Science Citation Index EXPANDED (1945 to March 2006), LILACS (1982 to March 2006), ClinicalTrials.gov (at www.clinicaltrials.gov) (accessed August 2006), ISI Web of Science (April 2006), and the International Standard Randomised Controlled Trial Number Register (at http://controlled-trials.com/isrctn/search.asp) (accessed August 2006). We also checked the reference lists of all the trials identified by the above methods.

SELECTION CRITERIA

We searched for randomised clinical trials irrespective of blinding, language, or publication status.

DATA COLLECTION AND ANALYSIS

We intended to summarise data by standard Cochrane Collaboration methodologies.

MAIN RESULTS

We could not find any randomised clinical trials with antifibrinolytic amino acids for upper gastrointestinal bleeding in patients with acute or chronic liver disease plus acquired coagulation disorders.

AUTHORS' CONCLUSIONS

We were unable to identify randomised clinical trials on the safety and efficacy of antifibrinolytic amino acids for upper gastrointestinal bleeding in patients with liver disease (acute or chronic) plus acquired coagulation disorders. The effects of antifibrinolytic amino acids has to be tested in randomised clinical trials.

The Use of Hemostatic Agents and Sealants in Urology

PURPOSE

While hemostatic agents and sealants have long been used in the fields of surgery and urology, confusion persists about their indications for use and the optimal agent choice. We comprehensively defined and evaluated the scientific basis for hemostatic agent and sealant use in urology, and provide a conceptual framework for future research and discussion.

MATERIALS AND METHODS

A MEDLINE search of all available literature concerning hemostatic agents in urology was performed, including topical hemostats, anti-fibrinolytics, fibrin sealants and matrix hemostats. Select references were also chosen from the broader surgical literature. Animal studies, case reports, retrospective and prospective studies, and opinion articles were reviewed.

RESULTS

Hemostatic agents include a wide range of components. Recent literature has focused on fibrin sealants and matrix agents. Two main indications exist for hemostatic agents, including 1) hemostasis and 2) sealant. The best evidence for efficacy and safety exists for hemostasis, especially for nephrectomy and trauma. Newer data highlight urinary tract reconstruction, fistula and percutaneous tract closure, suture line strengthening and infertility as potential uses. Novel drug delivery and tissue engineering are areas with large clinical potential.

CONCLUSIONS

Hemostatic agent use is promising and yet unproven for most conditions currently treated in urology. Hemostasis continues to be the main indication, which is well established. Few trials have examined comparative efficacy among hemostatic agents and further prospective studies are needed to justify additional indications as well as determine the optimal mode of use. Minimally invasive surgery will further drive the use of hemostatic agents and sealants. Cost-effective, evidence based hemostatic agent use will continue to challenge all urologists.

Coagulation abnormalities in critically ill patients

Many critically ill patients develop hemostatic abnormalities, ranging from isolated thrombocytopenia or prolonged global clotting tests to complex defects, such as disseminated intravascular coagulation. There are many causes for a deranged coagulation in critically ill patients and each of these underlying disorders may require specific therapeutic or supportive management. In recent years, new insights into the pathogenesis and clinical management of many coagulation defects in critically ill patients have been accumulated and this knowledge is helpful in determining the optimal diagnostic and therapeutic strategy.

Efficacy of desmopressin in preventing hemorrhagic complications in a patient with Marfan syndrome undergoing cardiac surgery

In this case report, we describe the successful use of desmopressin as prophylaxis against hemorrhage in a patient with a bleeding tendency associated with Marfan syndrome and a platelet function defect undergoing cardiovascular surgery.

Rapid administration of antifibrinolytics and strict blood pressure control for intracerebral hemorrhage

OBJECTIVE

Hematoma growth is a major cause of poor outcome in patients with intracerebral hemorrhage. We evaluated the efficacy of a combination of rapid antifibrinolytic therapy and strict blood pressure control for prevention of hematoma growth in this retrospective study.

METHODS

Systolic blood pressure was strictly controlled below 150 mm Hg by use of intravenously administered nicardipine (BPC). Prolonged infusion of antifibrinolytic therapy was given by intravenous administration of 1 g tranexamic acid over a period of 6 hours (PAF). Rapid administration of antifibrinolytic therapy was given by intravenous administration of 2 g tranexamic acid over a period of 10 minutes (RAF). Immediately after diagnosis of intracerebral hemorrhage on computed tomographic scan, 156 patients who were admitted within 24 hours of onset were treated with either a combination of PAF and BPC (PAF group) or a combination of RAF and BPC (RAF group). The incidence of hematoma growth determined by a second computed tomographic scan the day after admission was compared between the PAF and the RAF groups.

RESULTS

Hematoma growth was observed in 11 (17.5%) of 63 patients in the PAF group and 4 (4.3%) of 93 patients in the RAF group using a 20% cutoff value for hematoma enlargement. The RAF group showed a significantly low incidence of hematoma growth compared with the PAF group (P < 0.05). Between the two groups, there was no significant difference in any of the other factors reported to affect hematoma growth.

CONCLUSION

The combination of rapid administration of antifibrinolytics and strict blood pressure control may prevent hematoma growth in patients with intracerebral hemorrhage.

A propensity score case-control comparison of aprotinin and tranexamic acid in high-transfusion-risk cardiac surgery

BACKGROUND

Cardiac surgery with cardiopulmonary bypass may result in excessive fibrinolysis and platelet (PLT) dysfunction, resulting in impaired hemostasis and excessive blood loss. Prophylactic use of the antifibrinolytic drugs aprotinin and tranexamic acid is thought to prevent these hemostatic defects. Their relative clinical utility and safety in high-transfusion-risk cardiac surgery, however, is not known.

STUDY DESIGN AND METHODS

Using propensity scores, 449 patients who received aprotinin for high-transfusion-risk cardiac surgery were matched to 449 patients who received tranexamic acid from a pool of 10,870 consecutive patients who underwent cardiac surgery at a single center, 586 of whom received aprotinin and the remainder of whom received tranexamic acid.

RESULTS

The two matched groups were well balanced in terms of measured perioperative variables. Blood product transfusion rates were similar in the aprotinin and tranexamic acid groups: red blood cells, 79 percent versus 76 percent (p = 0.3); PLTs, 56 percent versus 50 percent (p = 0.06); and plasma, 66 percent versus 61 percent (p = 0.1). Adverse events rates were comparable in the two groups, except for renal dysfunction (defined as a greater than 50% increase in creatinine concentration during the first postoperative week to >100 micromol/L in women and >110 micromol/L in men or a new requirement for dialysis support), which occurred in 24 percent (107/449) of aprotinin patients and 17 percent (75/449) of tranexamic acid patients (p = 0.01).

CONCLUSIONS

Aprotinin and tranexamic acid have similar hemostatic effectiveness in high-transfusion-risk cardiac surgery. Within the confines of propensity score matching, our results suggest that aprotinin may be associated with renal dysfunction.

Tranexamic acid for hemostasis in the surgical treatment of metastatic tumors of the spine

STUDY DESIGN

This is a retrospective study of sequential cohorts.

OBJECTIVE

To assess the efficacy of tranexamic acid in decreasing operative blood loss and the need for intraoperative transfusion in metastatic spine surgery.

SUMMARY OF BACKGROUND DATA

Significant published data have established the efficacy of antifibrinolytic drugs in limiting surgical bleeding during heart surgery and total joint replacement. One study in scoliosis suggested benefit in spine surgery as well.

METHODS

During a 6-month trial period, 14 patients with spine cancer undergoing palliative intralesional tumor excision and concomitant instrumentation to stabilize the spine in the hands of a single surgeon were administered tranexamic acid intraoperatively in the attempt to minimize operative blood loss. They were then compared to the immediately preceding 14 patients.

RESULTS

Estimated operative blood loss was 1385 mL in the study group treated with tranexamic acid and 1815 mL in controls not receiving the drug, and was not found to be significantly decreased in this study.

CONCLUSIONS

Control of operative bleeding in metastatic spine surgery can be problematical. Optimum protocol might include routine preoperative angiographic tumor embolization to decrease lesion vascularity in all cases, but angiography is not without risk. Noninvasive prophylaxis of tumor bleeding would have obvious desirable advantages but was, unfortunately, not achieved in this study.

The efficacy and safety of epsilon-aminocaproic acid treatment in patients with cirrhosis and hyperfibrinolysis

BACKGROUND

Patients with decompensated cirrhosis are at risk for hyperfibrinolysis; this is potentially fatal. epsilon-aminocaproic acid has been used to treat patients with hyperfibrinolysis; however, the data about its benefit in the setting of cirrhosis are minimal.

AIM

To analyse the efficacy of epsilon-aminocaproic acid and its safety in cirrhotic patients with hyperfibrinolysis.

METHODS

All patients with an abnormal euglobin lysis time who were admitted to Rancho Los Amigos Medical Center from 1 January 2001 to 31 December 2002 were included in the study. Their medical records were reviewed and analysed.

RESULTS

There were 60 cirrhotic patients with shortened euglobin lysis time. Fifty-two patients received epsilon-aminocaproic acid. Of the 52 patients, seven had one or more bleeding episodes with the subcutaneous or soft tissue bleeding as the most common indication for epsilon-aminocaproic acid use. Of the 37 patients, 34 (92%) had improvement or resolution of their bleeding. Only two (3%) patients had epsilon-aminocaproic acid treatment discontinued because of minor side effects, rash and lightheadedness. There were no thromboembolic complications of treatment.

CONCLUSIONS

epsilon-aminocaproic acid was found to be effective and safe for treatment of hyperfibrinolysis in patients with cirrhosis.

Epsilon aminocaproic acid reduces transfusion requirements in patients with thrombocytopenic hemorrhage

BACKGROUND

Epsilon aminocaproic acid (EACA) is an antifibrinolytic drug that has been used to control hemorrhage by stabilizing the thrombus. It has been used in thrombocytopenic patients largely on an empiric basis.

METHODS

Concerns regarding side effects have limited the use of this drug. The authors reviewed their experience with EACA at the Cleveland Clinic Foundation from 1997 to 2003.

RESULTS

Of 77 patients with thrombocytopenic hemorrhage, 51 (66%) patients achieved a complete response and 13 (17%) patients achieved a partial response, resulting in a decrease in platelet and red blood cell transfusions. Adverse effects were manageable in this set of patients with severe underlying disease.

CONCLUSIONS

Based on this experience, EACA may be a valuable adjunctive therapy in the treatment of patients with thrombocytopenic hemorrhage.

Ultra-early Hemostatic Therapy for Acute Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) is the least treatable form of stroke, and causes high mortality, severe disability, and a staggering economic burden. ICH accounts for 15% of stroke cases in the United States and Europe, and up to 30% in Asian populations. Computed tomography-based studies suggest that ICH growth within the first few hours of onset is common, and the principal cause of early neurological deterioration. Hematoma volume is also a well-established predictor of 30-day mortality. Intervention with ultra-early hemostatic therapy could minimize or prevent this early dynamic bleeding process, and might improve outcome. Recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark) is approved for the treatment of bleeding in patients with hemophilia and inhibitors, but it may also promote hemostasis in patients with normal coagulation by acting locally at the bleeding site without activation of systemic coagulation. In a randomized, double-blind, placebo-controlled trial of 399 ICH patients treated with a single dose of 40, 80, or 160 microg/kg of rFVIIa or placebo within 4 hours of onset, subsequent hematoma growth was reduced by approximately 50% with rFVIIa. This was associated with a significant reduction (38%) in mortality, and improved functional outcomes among survivors. A phase III trial comparing 20 and 80 microg/kg rFVIIa with placebo is now in progress to confirm these results.

Management of bleeding emergencies: when to use recombinant activated Factor VII

Recombinant activated Factor VII (rVIIa) was originally released as a clotting factor, with use limited to a select group of patients who had few other treatment options. Due to the apparent ability of rVIIa to stop bleeding, no matter what the underlying cause, there is great interest in use of rVIIa in a wide range of bleeding patients. This article discusses rVIIa and its uses in a variety of patients, especially liver disease and trauma patients, and makes suggestions for appropriate use. Although most of the reports on rVIIa are anecdotes and case series, there is increasing data for clinical trials to help guide usage.

Dental procedures in adult patients with hereditary bleeding disorders: 10 years experience in three Italian Hemophilia Centers

Excessive bleeding after dental procedures are one of the most frequent complications occurring in patients with hereditary bleeding disorders. In this retrospective study we collected data from 10 years of experience in the oral care of patients with congenital haemorrhagic disorders in three Italian Hemophilia Centers. Between 1993 and 2003, 247 patients with inherited bleeding disorders underwent 534 dental procedures including 133 periodontal treatments, 41 conservative dentistry procedures, 72 endodontic treatments and 288 oral surgery procedures. We recorded 10 bleeding complications (1.9%), most of which occurred in patients with severe/moderate haemophilia A undergoing multiple dental extractions. Thus, our protocol of management of patients with hereditary bleeding tendency undergoing oral treatment or surgery has been shown to be effective in preventing haemorrhagic complications.

Bleeding in Cardiac Surgery: Its Prevention and Treatment—an Evidence-Based Review

Expected and unexpected bleeding occur frequently in patients undergoing cardiac surgery. Bleeding after cardiac surgery can be broadly divided into two groups: surgical (unrecognized bleeding vessel, anastomosis, or other suture line) or nonsurgical bleeding (caused by coagulopathy). Factors influencing both surgical and nonsurgical bleeding can be further broken down into those occurring preoperatively and those that occur intraoperatively and postoperatively. A thorough understanding of these factors is necessary to reduce bleeding. This is a desirable clinical goal, because excessive bleeding is associated with adverse outcomes.

Effect of intravenous hydroxyethyl starch on the accuracy of measuring hemoglobin concentration

STUDY OBJECTIVE

To determine if intravenous hydroxyethylstarch (HES) affects the accuracy of hemoglobin (Hb) measurements, as artificial colloids are known to increase red blood cell sedimentation rates.

DESIGN

Prospective, randomized study.

SETTING

Tertiary-care academic medical institution.

PATIENTS AND INTERVENTIONS

We randomized 40 surgical American Society of Anesthesiologists (ASA) physical status I and II patients undergoing preoperative autologous blood donation before elective orthopedic surgery. Patients were randomized to receive volume replacement with 500 mL of 6% HES 200,000/0.5 or 500 mL of electrolyte solution. Measurements of Hb concentration and leukocyte count were performed using an analyzer with a suction needle sampling from the bottom of the test tube. Measurements were performed after mixing and repeated after a 10-minute period of upright positioning of the tube (at rest).

MAIN RESULTS

In the study group that received HES, Hb levels were increased above baseline after resting (mean increase to 151% of baseline values, P < .01), whereas the leukocyte count was decreased (mean decrease to 39% of baseline values, P < .01). No difference between baseline and resting measurements were observed in patients who received intravenous crystalloids. In addition, we repeatedly measured the Hb concentration in an unstirred tube with and without the addition of HES. In blood samples containing HES, the Hb concentration was increased above baseline after 2.5 minutes of resting, compared with 30 minutes without HES addition (P < .05).

CONCLUSIONS

Mixing of test tube contents before sampling is critical for accurate measurement of the Hb concentration in the blood of patients who received intravenous HES.

Rehabilitation of a Hemophiliac With Implants: A Medical Perspective and Case Report

A patient suffering from classical hemophilia had previous surgery for ankylosis of the right temporomandibular joint. This was replaced by a costochondral graft and an overlay of temporalis muscle. A bilateral sagittal split was performed for a micrognathic mandible and a sleep apnea problem. That procedure solved the sleep apnea; however, it resulted in a prognathic mandible and an anterior open bite. The lower anterior teeth were periodontally involved with impaired alveolar support. The restricted opening of the oral cavity of 18 mm between maxillary and mandibular centrals and the potential danger of bleeding complicated the surgical and restorative procedures. The patient was prepared medically on each of 4 occasions with factor VIII replacement concentrate, and oral antifibrinolytic therapy (tranexamic acid). The treatment of choice was the extraction of the remaining lower incisors and their replacement with an implant-supported temporarily cemented retrievable fixed prosthesis. Serial extractions and chairside temporization provided the surgeon with precise guides for implant placement, and enabled the patient to enjoy unimpaired function through periods of healing and osseointegration.

Effectiveness in controlling haemorrhage after dental scaling in people with haemophilia by using tranexamic acid mouthwash

AIMS

To compare the effectiveness of tranexamic acid mouthwash (TAMW) in controlling gingival haemorrhage after dental scaling with that of using factor replacement therapy (FRT) prior to dental scaling in people with haemophilia.

DESIGN

Double-blind cross-over randomised control trial.

SETTING

Dedicated hospital dental practice for patients with inherited bleeding disorders.

METHOD

Sixteen patients with haemophilia who required dental scaling participated in this pilot study. The experimental treatment regime (ETR) involved transfusing each patient with saline before scaling both quadrants on one side of the mouth followed by oral rinsing with TAMW four times daily for up to eight days. The control regime (CR) involved giving each patient FRT before scaling the opposite side of the mouth followed by use of a placebo TAMW. Each patient underwent both treatments in a random-ised sequence. Both the operator and the patients were unaware of which were the ETR and CR episodes. On both occasions the patient kept a log book of the rinsing regime and any post-operative bleeding. Additionally, a structured post-treatment telephone interview was conducted to assess the effectiveness and the patient acceptability of the ETR.

RESULTS

Thirteen patients completed the study. No statistically significant difference was found in gingival bleeding and mouthwashing frequencies between the ETR and the CR (p > 0.05). Five patients reported no gingival bleeding with either the ETR or the CR. No patient, using either regime, required extra FRT due to gingival haemorrhage. All subjects found the ETR acceptable and easy and reported feeling safe in using TAMW alone to control gingival bleeding after dental scaling.

CONCLUSION

TAMW use after dental scaling was as effective as using FRT beforehand in controlling gingival haemorrhage for people with haemophilia.

Cardiac surgery in patients on antiplatelet and antithrombotic agents

The widespread application of antithrombotic agents carries significant potential for inducing excessive peri-operative hemorrhage during cardiac surgery. Specific surgical and medical strategies can be employed to attenuate this bleeding. These antithrombotic agents and anti-hemorrhagic measures will be reviewed in depth.

Treatment of von Willebrand disease

The bleeding tendency in von Willebrand disease (VWD) is heterogeneous and some patients with the mildest form of the disease have no significant bleeding symptoms throughout their lives. In some cases, the most difficult task for a clinician is to decide whether any treatment is actually required. However, cases with moderate to severe factor VIII (FVIII) and von Willebrand factor (VWF) deficiency usually require treatment to stop or prevent bleeding. Increasing autologous FVIII/VWF by desmopressin administration or providing normal allogeneic VWF through the infusion of plasma-derived concentrates can correct FVIII and VWF deficiencies and normalize or shorten bleeding time (BT). FVIII levels are the best predictors of soft tissue or surgical bleeding, while BT normalization, reflecting the correction of platelet-dependent functions of VWF, is considered a reliable indicator of an effective treatment of mucosal bleeding. Recombinant concentrates of FVIII are not indicated (apart from cases with alloantibodies against exogenous VWF), since they are devoid of VWF and lack its stabilizing effect on circulating FVIII. A very-high-purity concentrate of VWF has recently been made available, but its advantages over conventional concentrates containing both FVIII and VWF moieties are not obvious. The best way to select the appropriate treatment is to perform a test infusion with desmopressin in any patient with clinically significant VWD, provided that he/she has no contraindication to the compound or belongs to subtype with an anticipated lack of response (for example, type 3 VWD with FVIII/VWF lower than 5%).

Perioperative systemic haemostatic agents

Skilful surgery combined with blood-saving methods and careful management of blood coagulation will all help reduce unnecessary blood loss and transfusion requirements. Excessive surgical bleeding causes hypovolaemia, haemodynamic instability, anaemia and reduced oxygen delivery to tissues, with a subsequent increase in postoperative morbidity and mortality. The role of anaesthetists in managing surgical blood loss has increased greatly in the last decade. Position of the patient during surgery and the provision of a hypotensive anaesthetic regimen were once considered the most important contributions of the anaesthetist to decreasing blood loss. Now, several pharmacological haemostatic agents are being used by anaesthetists as blood-saving agents. After a brief discussion of the physiology of haemostasis, this article will review the evidence for the role of such agents in reducing perioperative blood loss and transfusion requirements.

Tranexamic acid in control of primary hemorrhage during transurethral prostatectomy

OBJECTIVES

To determine whether short-term treatment of patients about to undergo transurethral resection of the prostate (TURP) with tranexamic acid (TXA) would be beneficial in reducing the associated blood loss.

METHODS

A prospective and randomized trial was conducted with 136 men requiring TURP for obstructive urinary symptoms. The treatment group received 2 g TXA three times daily on the day of, and first day after, the operation.

RESULTS

Short-term TXA treatment significantly reduced the operative blood loss associated with TURP (128 mL versus 250 mL, P = 0.018), and this difference was not a result of the amount of tissue resected between the two groups (16 g versus 16 g, P = 0.415). In addition, TXA treatment reduced the amount of blood loss per gram of resected tissue (8 mL/g versus 13 mL/g, P = 0.020). Furthermore, the volume of irrigating fluid required (15 L versus 18 L, P = 0.004) and operating time (36 minutes versus 48 minutes, P = 0.001) were also reduced. However, TXA treatment did not influence the number of patients requiring a blood transfusion. Six patients in the treatment group (7.2%) and five in the control group (6.8%) required a transfusion (P = 0.709). Moreover, TXA treatment did not affect the duration of catheterization (1 day versus 1 day, P = 0.342) or hospitalization (3 days versus 3 days, P = 0.218).

CONCLUSIONS

Short-term TXA treatment is effective in reducing the operative blood loss associated with TURP.

Autologous Stem-Cell Transplantation Can Be Performed Safely Without the Use of Blood-Product Support

Purpose

Autologous stem-cell transplantation has been shown to be a curative procedure for a variety of leukemias and lymphomas. Most transplants require RBC and platelet support. We report the ability to perform autologous transplantation without blood-product support.

Subjects and Methods

In this study, we treated 26 patients with religious objection to blood products with autologous stem-cell support without the use of any blood products. Patients received a combination of granulocyte colony-stimulating factor (G-CSF), erythropoietin, and interleukin-11 or G-CSF alone to mobilize stem cells. Post-transplant patients received intravenous iron, erythropoietin, G-CSF, and epsilon aminocaproic acid.

Results

There were two major bleeding complications (8%), with two treatment-related deaths (8%). There were three minor bleeding complications (12%). The median fall in hemoglobin level was 4.7 g/dL; the median hemoglobin level 30 days after transplantation was 9.2 g/dL. The median total number of days with platelet count less than 10 × 109/L was 4 days; the median days to platelet recovery greater than 20 × 109/L was 12 days.

Conclusion

Autologous stem-cell transplantation can be performed safely without the use of any blood products.

Aprotinin inhibits local platelet trapping and improves tissue destruction in hepatic cryosurgery

BACKGROUND

During the last decade, cryosurgery became an interesting alternative in the treatment of nonresectable liver neoplasms. The freeze-thaw procedure, however, may be associated with life-threatening thrombocytopenia due to local platelet trapping, and success of neoplasm ablation may be compromised by inadequate parenchymal cell destruction.

METHODS

Because aprotinin is capable of inhibiting the initiation of both coagulation and fibrinolysis, we studied-by whole body scintigraphy of Indium-111-labeled platelets and histomorphology in a porcine model of hepatic cryosurgery-whether this serine protease inhibitor is effective in attenuating platelet trapping and in improving tissue destruction.

RESULTS

Fifteen minutes of cryotherapy (-168 degrees C at the tip of the cryoprobe) induced a 30 +/- 4 cm(3) cryolesion, which presented with massive platelet trapping (14.0 +/- 1.7% cryolesion activity/whole body activity) and incomplete parenchymal cell destruction (0.9 +/- 0.3; score of hepatocyte nuclear destruction within the margin of the cryolesion). Aprotinin treatment with 500,000 IU initial bolus injection and additional 500,000 IU infusion over 3 hours did not affect the size of the cryolesion (29 +/- 3 cm(3)) but reduced local platelet activity (1.9 +/- 1.9%; P<.001) and induced hepatocyte nuclear destruction (3.0 +/- 0.0; P<.001).

CONCLUSIONS

Thus, our study indicates that aprotinin inhibits cryoablation-associated platelet trapping and improves tissue destruction. The serine protease inhibitor may represent a valuable adjunct in cryosurgery of hepatic neoplasms.