Periprocedural thromboprophylaxis in patients receiving chronic anticoagulation therapy

Management of perioperative anticoagulation in patients with mechanical heart valve replacement undergoing laparoscopic cholecystectomy: a case report of postoperative cerebral embolism

Patients with mechanical heart valve replacement require lifelong anticoagulation therapy, and additional surgeries can pose a risk of bleeding and thromboembolic events due to the need for perioperative anticoagulation management. Here, we present a case report of a patient who underwent laparoscopic cholecystectomy (LC) and endoscopic retrograde cholangiopancreatography (ERCP) after mechanical heart valve replacement and experienced postoperative cerebral embolism. The management of perioperative anticoagulation in these patients is discussed, including strategies for minimizing the risks of bleeding and thromboembolic events during and after surgery.

Endodontics in Systemically Compromised Patients

A substantial number of people in today’s world are elderly and as the incidence of a number of pathologies increases with age, it is predicted to produce millions of individuals with systemic medical conditions that can affect oral health and subsequent dental treatment. The dental management of these medically compromised patients can be sometimes problematic in terms of oral complications, dental therapy, and emergency care. One of the challenges faced by dental specialists today is the assessment and management of these patients. As mentioned in detail in Chap. 12, geriatric patients are much more likely to be at least partially dentulous having a complex medical history and the use of multiple medications.

Outcomes of temporary interruption of rivaroxaban compared with warfarin in patients with nonvalvular atrial fibrillation: results from the rivaroxaban once daily, oral, direct factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and embolism trial in atrial fibrillation (ROCKET AF)

BACKGROUND

During long-term anticoagulation in atrial fibrillation, temporary interruptions (TIs) of therapy are common, but the relationship between patient outcomes and TIs has not been well studied. We sought to determine reasons for TI, the characteristics of patients undergoing TI, and the relationship between anticoagulant and outcomes among patients with TI.

METHODS AND RESULTS

In the Rivaroxaban Once Daily, Oral, Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF), a randomized, double-blind, double-dummy study of rivaroxaban and warfarin in nonvalvular atrial fibrillation, baseline characteristics, management, and outcomes, including stroke, non-central nervous system systemic embolism, death, myocardial infarction, and bleeding, were reported in participants who experienced TI (3-30 days) for any reason. The at-risk period for outcomes associated with TI was from TI start to 30 days after resumption of study drug. In 14 236 participants who received at least 1 dose of study drug, 4692 (33%) experienced TI. Participants with TI were similar to the overall ROCKET AF population in regard to baseline clinical characteristics. Only 6% (n=483) of TI incidences involved bridging therapy. Stroke/systemic embolism rates during the at-risk period were similar in rivaroxaban-treated and warfarin-treated participants (0.30% versus 0.41% per 30 days; hazard ratio [confidence interval]=0.74 [0.36-1.50]; P=0.40). Risk of major bleeding during the at-risk period was also similar in rivaroxaban-treated and warfarin-treated participants (0.99% versus 0.79% per 30 days; hazard ratio [confidence interval]=1.26 [0.80-2.00]; P=0.32).

CONCLUSIONS

TI of oral anticoagulation is common and is associated with substantial stroke risks and bleeding risks that were similar among patients treated with rivaroxaban or warfarin. Further investigation is needed to determine the optimal management strategy in patients with atrial fibrillation requiring TI of anticoagulation.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00403767.

Postoperative bleeding risk for cutaneous surgery in the head and neck region with continued phenprocoumon therapy

In a total of 171 surgical procedures for lesions in the head and neck region in patients in whom phenprocoumon therapy was not stopped, 16 (9%) postoperative bleeding events were observed over a follow-up period of two weeks. Local measures were sufficient in all cases except one severe case where blood transfusion was needed and anticoagulant treatment was stopped for 7 days. The bleeding risk was significantly higher for the surgical procedures of the nose than those in other areas (21% versus 6%, P = 0.014), but was not influenced by the international normalized ratio (INR) of blood coagulation, size, site and type of the lesion, surgical procedure, and sex and age of the patients. The bleeding rate in patients not on any anticoagulation therapy was significantly lower (6/211 = 3%). Across both groups, just over 80% of the bleeding episodes were within the first two days (55% on the same day and 32% on the next day) of the surgery. No bleeding was recorded after 5 days. Our data suggest that cutaneous surgery in the head and neck region can be safely performed with continued phenprocoumon therapy in most cases in an INR range of 1.3-3.4, but rarely severe bleeding does occur and can be managed with a close-contact follow-up and with 24-h on call services during the first two days postoperatively.

Risks related with withholding and resuming anticoagulation in patients with non-variceal upper gastrointestinal bleeding while on warfarin therapy

BACKGROUND

The use of warfarin is growing for the prevention or treatment of cardiovascular or cerebrovascular diseases. The risk of haemorrhagic side effects is increased in patients taking warfarin.

AIMS

To evaluate risks related with withholding and resuming anticoagulation in patients with upper gastrointestinal bleeding (UGIB) while on warfarin therapy and the role of the second-look endoscopic examination (SEE).

METHODS

Records of 58 patients with native valvular heart diseases who presented with non-variceal UGIB during chronic anticoagulation with warfarin were retrospectively reviewed. Age- and gender-matched patients with non-variceal UGIB during aspirin therapy because of ischaemic heart disease were recruited as the control group.

RESULTS

Development of both recurrent bleeding and thromboembolic events were more frequent in warfarin group than in control group (7.0% vs. 0% with p = 0.03 and 16.7% vs. 2.4% with p < 0.01, respectively). One of four cases of recurrent bleeding in warfarin group was found by SEE performed in an asymptomatic patient. There were six thromboembolic events which occurred on the 21st, 27th, 28th, 31st, 58th and 75th day from the presentation out of 36 patients who ceased anticoagulation. In contrast, only one from 41 in whom aspirin was discontinued experienced myocardial infarction. There was no difference in the failure of endoscopic haemostasis necessitating angiographic embolisation or surgery, hospital stay, the need of transfusion and overall mortality.

CONCLUSIONS

Anticoagulation is recommended to be resumed before the 20th day from the cessation to prevent thromboembolic events. A routine SEE before resuming anticoagulation might be helpful to detect asymptomatic recurrent bleeding.

Bleeding incidence after oral surgery with continued oral anticoagulation

OBJECTIVES

The aim of this retrospective study was to assess the incidence of postoperative hemorrhage in patients treated with coumarins without interruption of the anticoagulant treatment undergoing oral surgical procedures, mostly osteotomies for tooth removal, when compared with patients who had never been anticoagulated.

MATERIAL AND METHODS

Six hundred thirty-seven patients underwent 934 oral surgical procedures on an outpatient basis. The INR was measured preoperatively being 2.44 in the mean SD 0.61. Local hemostasis was carried out routinely (80%) with collagen fleece, local flap, and acrylic splint.

RESULTS

Of these 637 patients, 47 presented with a postoperative hemorrhage (7.4%), 15 of these 47 cases had to be treated in hospital (2.4%). All patients showed up finally with a good wound healing, no administration of blood was necessary, and local measures revealed to be sufficient in all cases except for two patients, where the preoperative anticoagulant treatment had to be changed for 6 days. The bleeding incidence in 285 patients with comparable oral surgical procedures, who had never been anticoagulated, was 0.7%.

CONCLUSIONS

The results suggest that oral surgical procedures can be performed safely without alteration of the oral anticoagulant treatment. CINICAL RELEVANCE: Local hemostasis with collagen fleece, local flap, and acrylic splint seems to be sufficient to prevent postoperative bleeding.

Thrombosis of A Prosthetic Mitral Valve After Withdrawal of Phenprocoumon Therapy

Patients with prosthetic heart valves require lifelong oral anticoagulant therapy based on vitamin K antagonists. These patients may need interruption of their anticoagulant therapy if they have to undergo surgery. The clinical challenge is to identify patients who can safely undergo surgery while continuing their vitamin K antagonist treatment and those who have to take short-acting heparin as part of a bridging therapy. Here we present a case of a patient with a prosthetic mitral valve whose oral anticoagulant therapy was unnecessarily discontinued by the GP prior to an upcoming cataract surgery. As a result, the patient developed thrombosis of the prosthetic mitral valve which needed to be surgically replaced.

Transversus abdominis plane block for an emergency laparotomy in a high-risk, elderly patient

A 72-year-old male patient with gall bladder perforation and small intestinal obstruction from impacted gall stone was posted for emergency laparotomy. He had congestive heart failure, severe hypertension at admission and history of multiple other coexisting diseases. On admission, he developed pulmonary oedema from systolic hypertension which was controlled by ventilatory support, nitroglycerine and furosemide. Preoperative international normalized ratio was 2.34 and left ventricular ejection fraction was only 20%. Because of risk of exaggerated fall in blood pressure during induction of anaesthesia (general or neuraxial), a transversus abdominis plane block via combined Petit triangle and subcostal technique was administered and supplemented with Propofol sedation.

Management of warfarin anticoagulation in patients with fractured neck of femur

Background. Most orthopaedic units do not have a policy for reversal of anticoagulation in patients with hip fractures. The aim of this study was to examine the current practice in a district general hospital and determine difference in the time to surgery, if any, with cessation of warfarin versus cessation and treatment with vitamin K. Methods. A retrospective review of the case notes between January 2005 and December 2008 identified 1797 patients with fracture neck of femur. Fifty seven (3.2%) patients were on warfarin at the time of admission. Patients were divided into 2 groups (A and B). Group A patients (16/57; 28%) were treated with cessation of warfarin only and group B patients (41; 72%) received pharmacological therapy in addition to stopping warfarin. Time to surgery between the two groups was compared. Results. The mean INR on admission was 2.9 (range 1.7–6.5) and prior to surgery 1.4 (range 1.0–2.1). Thirty eight patients received vitamin K only and 3 patients received fresh frozen plasma and vitamin K. The average time to surgery was 4.4 days in group A and 2.4 days in group B. The difference was statistically significant (P < .01). Conclusion. Reversal of high INR is important to avoid significant delay in surgery. There is a need for a national policy for reversing warfarin anticoagulation in patients with hip fractures requiring surgery. Vitamin K is safe and effective for anticoagulation reversal in hip fracture patients.

Thyroid nodule and thyroid cancer management pre- and post-cardiac transplantation

Thyroid nodules are common in the adult population. Widespread use of sensitive imaging studies often leads to their incidental discovery. Recent guidelines recommend thyroid-stimulating hormone determination and ultrasonography during initial nodule evaluation. Fine-needle aspiration is often performed to detect malignancy. However, the management of thyroid nodules in cardiac transplantation patients has not been directly addressed by recent guidelines. Confounding medications such as amiodarone and anti-coagulants present a management dilemma. The timing of fine-needle aspiration is crucial because (1) malignancy diagnosed pre-operatively usually precludes organ transplantation, and (2) patients undergoing solid-organ transplantation are at increased risk of developing de novo malignancies, including thyroid. With the rising incidence of thyroid cancer, donor-related malignancy will likely become a more prominent issue. This review addresses thyroid nodule management in the cardiac transplant population and provides recommendations for organ donation and transplantation in donors and recipients with thyroid cancer.

Periprocedural antithrombotic management: a review of the literature and practical approach for the hospitalist physician

Many patients who are on long-term antithrombotic therapy (e.g. warfarin and/or antiplatelet agents) must be assessed for temporary discontinuation for a procedure or surgery, making this a salient topic for the hospitalist physician. Discontinuation of antithromhotic therapy can place patients at increased risk of thromboembolic complications while continuing antithrombotic therapy can increase procedure-related bleeding risk. Bridging anticoagulation with heparin or low molecular weight heparins is often used in the periprocedural period, but a great deal of uncertainty exists about how and when to use bridging anticoagulation. Because there is very little Level 1 evidence to define optimal care, both clinical practice and expert consensus guideline opinions vary. For the hospitalist, it is of critical importance to understand the available data, controversies, and management options in order to approach patient care rationally. This review provides a step-wise literature-based discussion addressing the following four questions: (1) What is the optimal management of antiplatelet therapy in the periprocedural period? (2) Are there very low bleeding risk procedures that do not require interruption of oral anticoagulation? (3) Are there low thromboembolic risk populations who do not require periprocedural bridging? (4) How do you manage patients who must discontinue anti-coagulants but are at an increased thrombotic risk?

[Update in pulmonary thromboembolic disease]

Pulmonary embolism is part of venous thromboembolism, an important health problem which leads to significant mortality and morbidity with high economic and social burden. A prompt diagnosis and treatment as well as an appropriate prophylaxis are determinant factors in prognosis. This disease continues to demand particular attention namely in the investigation of risk factors, clinical probability algorithms development, diagnostic work-up evaluation, characterization of new therapeutic strategies and thromboprophylaxis recommendations. The present review looks into the current scientific knowledge regarding pulmonary embolism.

Craniotomy with prosthetic heart valves: a clinical dilemma

The authors report two cases of spontaneous intracranial haemorrhage after elective craniotomy for resection of cerebral tumour. Both patients had mechanical aortic valve prostheses and were on regular warfarin therapy. In both cases, warfarin therapy was discontinued 5 days prior to surgery and unfractionated heparin administered intravenously until 12 h before surgery. Both patients were re-anticoagulated with subcutaneous low molecular weight heparin within the first week postcraniotomy-both developed life-threatening intracranial haemorrhage requiring urgent evacuation. The authors emphasize the risk of re-anticoagulation without postoperative imaging and the disadvantages of therapeutic dose, low molecular weight heparin in the postoperative period.

Management of surgical patients receiving anticoagulation and antiplatelet agents

BACKGROUND

Temporary interruption of long-term anticoagulation and antiplatelet therapy during surgical procedures exposes patients to thrombotic risk. Continuation of these agents, however, is associated with an increased risk of bleeding. Managing anticoagulation can be a particular challenge in the emergency setting.

METHODS

A literature review of published articles sourced using the keywords heparin, warfarin, perioperative, antiplatelet, aspirin and surgery was undertaken. A management plan for all likely situations was developed.

RESULTS AND CONCLUSION

Based on an individual assessment of risk factors for arterial or venous thromboembolism and the risk of perioperative bleeding, it is possible to form an anticoagulant and antiplatelet management plan likely to achieve a low incidence of bleeding and thrombosis. A multidisciplinary approach is desirable.

Current evidence on anticoagulant management and outcomes for postpolypectomy: an integrative literature review to assist advanced practice nurses

Currently, there is a scarcity of research evaluating the safety of performing endoscopies, with or without biopsies, among anticoagulated patients. The purpose of this study was to perform an integrative literature review of current research from 1999 through 2005 on anticoagulant management options and outcomes for postpolypectomy patients. Imogene King's model of nursing was used as a guide for this study. Ten research studies were identified via computerized search of the Cumulative Index of Nursing and Allied Health Literature, MEDLINE, and PubMed databases and were limited to studies published in English and studies of rigorous design reporting evidence of direct management. This method of review was modeled after L. H. , who advised analyzing data in a systematic fashion. Comparison of management and outcomes of postpolypectomy patients was conducted, followed by a discussion of the findings. Findings indicated that an adjustment of warfarin doses for the purpose of endoscopy is not necessary, with the exception of clinically complex cases. Studies found no increase in incidence of thromboembolus events when warfarin was adjusted or held. While one study found a case of hemorrhagic complication due to continuation of warfarin, there was no evidence presented that indicated surgery or mortality as a result of this complication. Implications for advanced nursing practice, patient education, and further research are discussed.

Antithrombotic treatment for patients on oral anticoagulation undergoing coronary stenting

BACKGROUND

Dual antiplatelet treatment with aspirin and a thienopyridine is the antithrombotic treatment recommended after coronary stenting. Such strategy is generally not applicable in most patients with an indication for oral anticoagulation (OAC), for whom however, information about the optimal antithrombotic regimen is currently limited.

METHODS

In order to derive some practical indications for the clinicians who are requested to care for these patients, the available evidence on the use, safety and efficacy of the various antithrombotic strategies was reviewed.

RESULTS

A substantial variability in the choice of treatment was observed in current practice where, however, standardized management protocols are seldom used. Triple therapy with OAC, aspirin and a thienopyridine is the most frequently adopted regimen, although its safety appears suboptimal, due to an apparent increased incidence of major hemorrhagic complications. Conversely, the efficacy of the combination of OAC and aspirin is suboptimal, so that such regimen should be considered only for patients at very high hemorrhagic risk, and in association with the implantation of more "biocompatible" stents.

CONCLUSIONS

While waiting for further studies to generate more consistent evidence, the choice of the antithrombotic treatment for patients with an indication for OAC undergoing coronary stenting should be guided by careful stratification of both thrombotic/thromboembolic and hemorrhagic risks. In general, however, the implantation of drug-eluting stents should be avoided, due to the prolonged need for dual antiplatelet administration, and the radial approach preferred, due to the virtual elimination of bleeding complications at the arterial access site.

Post-sphincterotomy bleeding: who, what, when, and how

Endoscopic biliary sphincterotomy (ES) is the cornerstone of therapeutic endoscopic retrograde cholangiopancreatography (ERCP). Bleeding is one of the most frequent complications following ES. Rates of post-ES bleeding vary widely and its presentation may be immediate (intraprocedural) or several days later. Clinically, bleeding can range from insignificant to life threatening. Most bleeding episodes are managed successfully by conservative measures with or without endoscopic therapy. Endoscopic treatment options include injection, thermal, and mechanical methods-alone or in combination. For refractory cases, angiographic embolization, or surgery, is necessary. Both technical risk factors and patient risk factors contribute to the development of post-ES bleeding. When these risk factors are present, measures can be taken to reduce the risk of bleeding. In this manuscript the literature on post-ES bleeding is reviewed.

Bridging therapy in patients on long-term oral anticoagulants who require surgery: the Prospective Peri-operative Enoxaparin Cohort Trial (PROSPECT)

BACKGROUND

The peri-operative management of patients on oral anticoagulants (OACs) is a common clinical problem. Our aim was to determine the incidence of major bleeding during peri-operative administration of treatment-dose enoxaparin and the impact of the extensiveness of the procedure on the risk of bleeding.

METHODS

We performed a prospective cohort study of 260 patients at 24 North American sites on OACs for atrial fibrillation or a history of deep vein thrombosis (DVT) requiring invasive or surgical procedures whose treating physician felt that bridging therapy was required. Warfarin was withheld, and once-daily s.c. enoxaparin (1.5 mg kg(-1)) was given peri-operatively. Patients were followed for 28 days after OAC was therapeutic.

RESULTS

Major bleeding was observed in nine of 260 patients (3.5%, 95% CI: 1.6-6.5). The bleeding risk varied markedly by extensiveness of procedure: the incidence of major bleeding for invasive procedures, minor surgery and major surgery was 0.7% (95% CI: 0.02-3.7), 0% (95% CI: 0-5.0), and 20.0% (95% CI: 9.1-35.7), respectively. There were five thromboembolic events in total (1.9%, 95% CI: 0.6-4.4). There were four arterial events (2.3%, 95% CI: 0.6-5.7) in 176 patients with atrial fibrillation, and one venous event (1.0%, 95% ci: 0.03-5.7) in 96 patients with prior DVT/ CONCLUSIONS: Bridging therapy with once-daily therapeutic-dose enoxaparin administered primarily in an outpatient setting has a low incidence of major bleeding for patients undergoing invasive procedures and minor surgery. Further studies are needed to optimize the bridging strategy for patients undergoing major surgery.

Aortic Valve Replacement in a Patient With the Prothrombin 20210A Mutation

Patients presenting for cardiac surgery with hypercoagulable states pose a challenge. Although preoperative functional and genetic screening for hypercoagulable disorders may provide pathophysiologic information, it is difficult to make preoperative hematologic management plans in the absence of consensus guidelines, prospective studies, or case reports. We document the first case of prothrombin 20210A mutation in a patient undergoing elective aortic valve replacement. Peri-procedural bridging with heparin and avoidance of antifibrinolytic agents represent salient features of our successful perioperative management.

Dentoalveolar Procedures for the Anticoagulated Patient: Literature Recommendations Versus Current Practice

PURPOSE

To evaluate the current practice of oral and maxillofacial surgeons in Michigan regarding perioperative warfarin therapy and dentoalveolar surgery in defined procedure risk groups.

MATERIALS AND METHODS

Surveys were distributed to all surgeons (n = 188) registered with the Michigan Society of Oral and Maxillofacial Surgeons. Low/moderate/high surgery risk groups were defined based on retrospective data accumulated for procedures on pretransplant liver failure patients. We requested the surgeon's maximum tolerated International Normalized Ratio (INR) for each risk group. In addition, surgeons were asked if their routine practice for each group included continuation or discontinuation of therapeutic warfarin perioperatively.

RESULTS

A 72.6% response rate was achieved. The average maximum INR cutoff values for the various risk groups were: low, 2.68; moderate, 2.28; and high, 2.01. Routine discontinuation of warfarin occurred in these groups 23.6%, 48.8%, and 70.5%, respectively. Using a paired t test, these results showed statistically significant differences in patient management practices (P < .001) between the low, moderate, and high risk groupings.

CONCLUSION

Lack of uniformity exists regarding warfarin therapy and dentoalveolar surgery. No studies to date involve significant numbers of moderate/high risk procedures to provide evidence-based support of safety with maintenance of therapeutic INR. For moderate or high risk procedures, the majority of surgeons prefer warfarin discontinuation with minimally therapeutic or subtherapeutic levels, a practice that secondarily increases risk for thromboembolism. Based on these preliminary data, we believe a prospective trial to elucidate stronger management guidelines for both the moderate and high risk surgery population is indicated.

Periprocedural and medium-term antithrombotic strategies in patients with an indication for long-term anticoagulation undergoing coronary angiography and intervention

OBJECTIVES

The optimal antithrombotic treatment for patients on long-term anticoagulation undergoing invasive coronary procedures is currently undefined. The strategies adopted periprocedurally and medium-term after coronary stenting (percutaneous coronary intervention with stent implantation) at our Institution, were reviewed, and the safety and efficacy of the various regimens evaluated.

METHODS

All patients undergoing invasive coronary procedures between January 2002 and December 2004 were retrospectively identified.

RESULTS

Out of 3709 patients overall, 104 (2.8%; 95% confidence interval 2.3-3.4) were on warfarin (because of atrial fibrillation in >50% of cases), whereas this was the case for 49 (3.1%; 95% confidence interval 2.3-4.1) of 1584 undergoing percutaneous coronary intervention with stent implantation. The antithrombotic strategies were highly variable, both periprocedurally (i.e. warfarin withdrawal or substitution by heparin, followed by aspirin with or without a thienopyridine) and medium-term after percutaneous coronary intervention with stent implantation (i.e. combination of warfarin and single or dual antiplatelet agents or pure dual antiplatelet treatment). Overall, periprocedural hemorrhages occurred in five patients (4.8%; 95% confidence interval 1.56-11.22). No thromboembolic events were observed, whereas one subacute stent thrombosis occurred (2%; 95% confidence interval 0.05-11) during warfarin and aspirin treatment. Among patients undergoing percutaneous coronary intervention with stent implantation, 1-month hemorrhagic rate was 10% (95% confidence interval, 3.3-23.8); most hemorrhages (major bleeds in three-quarters of cases) occurred during triple therapy with warfarin (or low-molecular-weight heparin), aspirin and a thienopyridine.

CONCLUSIONS

At our Institution (where standardized protocols are currently not in use), periprocedural and medium-term antithrombotic treatment in patients on long-term anticoagulation undergoing percutaneous coronary intervention with stent implantation showed substantial variability. As a result of the relevant 1-month complication rate, further properly sized and designed studies are warranted to identify the optimal strategies for this patient subset, which is foreseen to progressively increase over the next years.

National survey of anticoagulation policy in endoscopy

BACKGROUND

Anticoagulated patients who need to undergo endoscopy present unique challenges to the gastroenterologist. The continuation of anticoagulant therapy increases the risk of haemorrhagic complications of gastrointestinal endoscopy. Reversing the anticoagulation increases the risk of thromboembolism. In our experience in various endoscopy units, there are variable policies on the management of anticoagulated patients undergoing gastrointestinal endoscopy.

METHODS

To study the current practice, survey questionnaires were sent to 2320 doctors, working in 231 hospitals across the United Kingdom.

RESULTS

Responses were obtained from 219 hospitals (94.8%), but only from 434 doctors (18.7%). The results show 40.8% endoscopists continued the patients on warfarin when performing a planned upper gastrointestinal endoscopy, whereas 26% stopped it; 33.2% gave varying reports, that is, they used their own judgement according to the disease for which the anticoagulant was being given. For planned lower gastrointestinal endoscopy, 48.7% doctors preferred to stop warfarin; 53.3% of the endoscopists stated that they have a policy in place at their hospital for both upper and lower gastrointestinal endoscopy in anticoagulated patients; 5.5% had a policy for upper gastrointestinal endoscopy only and 6.2% for lower gastrointestinal endoscopy only. Thirty-five per cent doctors reported that they did not have any standard policy. We compared the responses from within a hospital to see whether the doctors were uniformly aware of an existing policy in their hospital. For upper gastrointestinal endoscopy, the responses were the same (either yes or no) by 51% of the doctors, whereas they were different by 49%. For lower gastrointestinal endoscopies, the same response was given by 49% of the doctors, whereas 51% gave different answers. The poor response rate from the doctors, however, makes firm interpretation of the data difficult.

CONCLUSIONS

A wide variation in practice is seen across the country. A robust national guideline to streamline the endoscopy practice in anticoagulated patients is needed.

Transdermal delivery of heparin using pulsed current iontophoresis

PURPOSE

In clinical practice heparin has to be administered by injection with obvious disadvantages; thus, transdermal delivery by electrically assisted methods have been studied. In this study we evaluated the efficacy of a Food and Drug Administration-approved pulsed current iontophoresis system in delivering heparin through living rat skin.

METHODS

Fluorescent and radioactive heparin as well as a commercial heparin preparation were delivered through rat skin via a pulsed current iontophoresis system.

RESULTS

Pulsed current iontophoresis allowed fluorescent heparin to cross the stratum corneum localizing in epidermis and dermis. Unfractionated, high-, and low molecular weight fraction pools, obtained by fractionating [35S]-unfractionated heparin on a molecular weight sieve, were then separately tested. Pulsed current iontophoresis elicited the transdermal delivery of low molecular weight heparin, but not that of high molecular weight heparin. Finally, pulsed current iontophoresis of an unfractionated pharmaceutical heparin preparation significantly decreased plasmatic factor Xa activity.

CONCLUSIONS

We hypothesize that this technique could be used to administer low molecular weight heparin in a cost-efficient and safe manner without the need for syringes and needles.

The safety of open inguinal herniorraphy in patients on chronic warfarin therapy

BACKGROUND

The perioperative management of warfarin therapy increases the complexity of open inguinal herniorraphy.

METHODS

One thousand consecutive patients undergoing open inguinal herniorraphy were retrospectively reviewed. Patients on warfarin therapy were categorized into 3 groups: continued warfarin (CW), discontinued warfarin (DW), and discontinued warfarin with anticoagulation bridge (DWB).

RESULTS

Eighty-eight patients were on chronic warfarin therapy. Warfarin was continued in 19 patients, discontinued in 54, and discontinued with bridge in 15 patients. Operative times were similar between the 3 groups. Length of stay was longest in the discontinued warfarin with bridge group (CW 0.74, DW 0.54, and DWB 3.33 days; P < .0001). There was no significant difference in postoperative complications. The incidence of surgical site hematoma was higher in the continued warfarin and discontinued warfarin with bridge groups (CW 11%, DW 2%, and DWB 13%; P = .14).

CONCLUSIONS

Continuation of warfarin may be a safe alternative to discontinuation of warfarin therapy in select patients undergoing open inguinal herniorraphy.

Endoscopic dacryocystorhinostomy in warfarinized patients

PURPOSE

To report the results of endoscopic dacryocystorhinotomy (EDCR) in anticoagulated patients who did not interrupt their anticoagulant regimen for the procedure.

MATERIALS AND METHODS

A case note review was made of all 9 patients taking warfarin who had EDCR at Ipswich Hospital from May 1998 to October 2003. Age, gender, indications for surgery, complications, and outcome were analyzed, and the results were compared to EDCRs in nonwarfarinized patients.

RESULTS

Of the 9 patients, 7 had complete relief of epiphora. Two patients had a persistent watering eye. One of them had blockage of upper, lower, and common canaliculi, and the other was found to have adhesions between the lateral nasal wall and middle turbinate. A total of 6 patients had no postoperative complications; 2 had minor periorbital bruising that did not delay discharge, and only 1 patient had ooze through a Kaltostat nasal pack and was kept in the hospital for 2 days. None required readmission.

CONCLUSIONS

EDCR is a safe and efficacious treatment in patients with distal nasolacrimal obstruction in anticoagulated patients and does not require stopping the warfarin perioperatively.

Periprocedural bridging therapy in patients receiving chronic oral anticoagulation therapy

BACKGROUND

In patients receiving chronic oral anticoagulation with vitamin K antagonists (VKAs) it may be necessary to temporarily discontinue VKA therapy to allow surgery or other invasive procedures to be performed, as maintaining treatment may increase the risk of bleeding during the procedure. This, however, creates a clinical dilemma, since discontinuing VKAs may place the patient at risk of thromboembolism.

SCOPE

We undertook a systematic narrative review of patients on chronic oral anticoagulation, requiring a periprocedural bridging therapy with heparin during invasive procedures.

FINDINGS AND RECOMMENDATIONS

For patients requiring temporary discontinuation of VKA, current guidelines recommend the use of 'bridging' therapy with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) in patients considered to be at intermediate-to-high risk of thromboembolism, such as those with prosthetic heart valves or atrial fibrillation. Recent studies show that LMWHs are associated with low rates of thromboembolism and, when compared with UFH, are as effective and safe as UFH when used as periprocedural bridging therapy in such patients. LMWHs also offer advantages such as ease of administration and predictable anticoagulant effects. Moreover, outpatient-based periprocedural bridging therapy with LMWH has been shown to result in significant cost savings compared with in-hospital UFH.

CONCLUSIONS

The decision to provide bridging therapy requires careful consideration of the relative risks of thromboembolism and bleeding in each patient. Based upon the studies reviewed we recommend a therapeutic dose of UFH or LMWH for patients at intermediate-to-high thromboembolic risk requiring interruption of VKA, especially for low bleeding risk procedures. We would like to propose upgrading the American College of Chest Physicians (ACCP) guideline recommendations from 2C to 1C. However, there is still a need for a randomized controlled trial on the efficacy and safety of the available bridging strategies, including heparin and placebo comparators, in preventing thromboembolism for specific patients and procedures.

Optimal antithrombotic treatment in patients with an indication for long-term anticoagulation undergoing coronary artery stenting

Dual antiplatelet treatment with aspirin and either ticlopidine or clopidogrel is recommended after percutaneous coronary intervention with stent implantation (PCI-S). However, in patients with an indication for oral anticoagulation (OAC) undergoing PCI-S with an indication for long-term OAC – because of atrial fibrillation, mechanical heart valve or previous thromboembolism – the optimal antithrombotic treatment is unknown. The limited evidence available shows substantial variability in the management of these patients, for whom the adopted strategies include substitution of OAC for dual antiplatelet therapy, addition of a single antiplatelet agent to OAC and institution of triple therapy with OAC, aspirin and a thienopyridine. Both the efficacy and safety of the various regimens appear suboptimal, with a 30-day occurrence of thrombotic and major bleeding complications of 4 and 3–7%, respectively. Large-scale registries and clinical trials are warranted to determine the optimal antithrombotic treatment in these patients whose number is likely to progressively increase over the coming years. In the meantime, periprocedural, medium-

and long-term antithrombotic treatment should be based on accurate risk stratification of thrombo(embolic) complications.

Therapy Insight: approaching endoscopy in anticoagulated patients

Over the past decade, the application of anticoagulant and antiplatelet agents for various cardiovascular and hematologic conditions has become more widespread. Optimal management of these agents during the periendoscopic period requires consideration, but limited prospective data mean that guidelines have largely relied on expert opinion. Elective procedures should be delayed in patients on temporary anticoagulation therapy (e.g. those with deep vein thrombosis). For procedures considered to have a low risk of bleeding (e.g. diagnostic endoscopy and colonoscopy without polypectomy) there is no need to discontinue or adjust anticoagulation. For procedures with a higher risk of bleeding (e.g. polypectomy and biliary sphincterotomy) an individual approach is required. This approach might include stopping oral anticoagulant therapy with or without the administration of unfractionated heparin or low-molecular-weight heparin for the preprocedure and postprocedure periods, during which the patient's international normalized ratio is in the subtherapeutic range.

Anticoagulation management in hip fracture patients on warfarin

The management of patients admitted with a fracture requiring surgery who are taking warfarin anticoagulation is unclear. We examined the anticoagulation management for 33 hip fracture patients on warfarin at the time of admission. Hospital course and complications were recorded on all patients. The mean INR on admission was 3.2 and prior to surgery 2.2. Eight patients (24%) had percutaneous cancellous screws for an intracapsular fracture regardless of the admission INR. In 21 (64%) patients, surgery was delayed whilst the INR came down, with an average delay of 72 h from admission to surgery. No specific treatment to lower the INR, other than wait and watch policy adopted in 11 (33%) of these patients. Pharmacological methods used to reduce the INR were fresh frozen plasma in nine cases, and intravenous Vitamin K in four patients. One patient died from post-operative haematemesis and three died from medical complications unrelated to the warfarin therapy. There were no wound haematomas or other bleeding complications. Delaying surgery whilst waiting for the INR to fall to acceptable levels may result in significant delays to surgery and we would recommend a more aggressive policy to enable earlier surgery.

Vermeidung von Notfallsituationen bei gerinnungshemmender Therapie mit Vitamin-K-Antagonisten

Despite 50 years of clinical experience with vitamin K antagonists such as phenprocoumon or warfarin, many clinicians are uncertain how to start treatment, deal with overdose or bleeding complications, and how to bridge anticoagulation when treatment with vitamin K antagonists is interrupted. Patients with overdose of vitamin K antagonists or bleeding complications are treated with vitamin K, prothrombin complex concentrates (PCC), or recombinant factor VIIa. Rapid reversal of anticoagulation is only achieved by using PCC or recombinant factor VIIa. Both should be combined with vitamin K for a sustained effect. For elective surgery, treatment with vitamin K antagonists is paused and vitamin K given either orally or intravenously. Unfractionated or low molecular weight heparin is given when INR levels are below therapeutic range. Patients with contraindications to heparin may be treated with alternative anticoagulants such as danaparoid, lepirudin or fondaparinux.

Drug Insight: an overview of current anticoagulation therapy after heart valve replacement

Vitamin K antagonists, such as warfarin, are the gold standard approach for the long-term anticoagulant therapy of patients with mechanical heart valves. Management decisions are, however, based predominantly on expert consensus and on data from nonrandomized, follow-up studies, which have inherent limitations in their methods. Low-intensity anticoagulation therapy provides protection against thromboembolic complications in patients with most types of modern prosthetic heart valve. The addition of low-dose aspirin is safe if international normalized ratio values below 3.5 are maintained. A combined regimen should be considered in high-risk patients and those with coexistent coronary artery or cerebrovascular disease, and in patients who have suffered a thromboembolic event despite a therapeutic international normalized ratio. Thromboprophylaxis with unfractionated or low-molecular-weight heparins is restricted to specific situations, such as when a patient is intolerant to vitamin K antagonists, when surgical procedures require discontinuation of oral anticoagulation, or when the patient is pregnant. A lack of uniformity across practice guidelines make it difficult to reach treatment decisions. Each patient's preference, expressed after counseling about the risks and benefits of each treatment strategy, and an individual assessment of the patient's risk factors, should guide treatment decisions. At present, new anticoagulant agents such as factor Xa inhibitors do not represent a treatment option for heart valve recipients.

[Perioperative anticoagulation management for prosthetic heart valves]

OBJECTIVES

The practices and the guidelines over the perioperative management of the anticoagulation of patients with cardiac valves prothesis are the object of no consensual attitude. The thrombotic risk over the time is well known. It depends of the type or the location on the valve, of their associations and the age of the patient. In the perioperative period, the antithrombotic treatment must be interrupted according to the surgical haemorrhagic risk.

STUDY DESIGN

Short review.

RESULTS

Only patients, without associated risk factor, carriers of bioprosthesis from more than 3 months, can be maintained only under antiplatelets agents. In others situations, the caution imposes a bridge of anticoagulants from 48 to 72 hours with unfractionated heparin (subcutaneous at home, intravenous at the hospital). Low molecular weight heparin has no commercial authorization in this indication. The resumption of the anticoagulation by unfractionated heparin in postoperative period must be the most premature possible after the decrease of the surgical bleeding. The relay by vitamin K antagonists has to be made over 48 to 72 hours. Within the framework of the urgency, the surgical haemorrhagic risk is weak for an INR <1.5. According to the urgency of the surgery, a treatment by vitamin K (if the delay is over 12 hours) or by prothrombinic complex allows to correct this INR. The identification of thrombotic complications requires a particular attention. In the postoperative period, as soon as there is suspicion of thrombosis, clinical manifestations must be consolidated by the practice of a transoesophageal echography, which only confirm the diagnosis.

The Plastic Surgeon??s Guide to Drugs Affecting Hemostasis

The plastic surgeon is encountering an unprecedented population of aging individuals who both desire cosmetic or reconstructive surgery and may require the use of medications that alter hemostasis. The increasing use of anticoagulants and platelet inhibitors in particular can create challenges for the plastic surgeon. The purpose of this review is to familiarize the surgeon with the medications that can affect hemostasis and to suggest strategies for their use in the perioperative period. Specific case examples are presented.

Vitamin K antagonists and direct thrombin inhibitors: present and future

Warfarin and related compounds are efficacious and safe in a variety of clinical thrombotic disorders; however, these drugs have a narrow therapeutic window, whereby inadequate therapy is associated with an increased thrombotic risk and overanticoagulation is associated with bleeding. Therefore, attempts have been made to develop alternatives to warfarin. Ximelagatran, an oral direct thrombin inhibitor, has been shown to be as efficacious and safe as warfarin for the prevention and treatment of different thrombotic disorders. This article reviews the pharmacology of the coumarins, the most commonly used vitamin K antagonists, and the practical aspects regarding their use in the management of thrombotic disorders. The future role of the oral direct thrombin inhibitor ximelagatran also is reviewed.