Bleeding complications with enoxaparin for deep venous thrombosis prophylaxis

Incidence of Venous Thromboembolism after Primary Total Hip Arthroplasty with Mechanical Prophylaxis in Hong Kong Chinese

Purpose

The incidence of deep vein thrombosis (DVT) following total hip arthroplasty (THA) without chemoprophylaxis could be as high as 50% in Caucasians. However, according to several subsequent studies, the incidence of venous thromboembolic events (VTE) in Asians was much lower. The routine use of chemoprophylaxis, which could potentially cause increased bleeding, infection, and wound complications, has been questioned in low-incidence populations. The objective of this study is to determine the incidence of VTE after primary THA without chemoprophylaxis in an Asian population using a fast-track rehabilitation protocol and to verify the safety profile for use of 'mechanical prophylaxis alone' in patients with standard risk of VTE.

Materials and Methods

This is a retrospective cohort study of 542 Hong Kong Chinese patients who underwent primary THA without chemoprophylaxis. All patients received intermittent pneumatic compression and graduated compression stockings as mechanical prophylaxis. Multimodal pain management was applied in order to facilitate early mobilisation. Routine duplex ultrasonography was performed between the fourth and seventh postoperative day for detection of proximal DVT.

Results

All patients were Chinese (mean age, 63.0±11.9 years). Six patients developed proximal DVT (incidence rate, 1.1%). None of the patients had symptomatic or fatal pulmonary embolism.

Conclusion

The incidence of VTE after primary THA without chemical prophylaxis can be low in Asian populations when following a fast-track rehabilitation protocol. Mechanical prophylaxis alone can be regarded as a reasonably safe practice in terms of a balanced benefit-to-risk ratio for Asian patients with standard risk of VTE.

Patients Undergoing Primary Total Joint Arthroplasty with Primary Hypercoagulable States

Objective

To analyze perioperative complications, resource consumption, and inpatient mortality of patients who receive total joint arthroplasty (TJA) with a concomitant diagnosis of a primary hypercoagulable state (PHS). The following questions were posed in the present paper. First, do patients undergoing TJA with PHS have increased risk of deep venous thrombosis (DVT), pulmonary embolism (PE), and periprosthetic joint infection (PJI)? Second, what other in‐hospital complications are more likely among PHS patients undergoing TJA? Third, do TJA patients with PHS usually consume greater in‐hospital resources? Fourth, do PHS patients suffer higher mortality rates compared to non‐PHS patients? Finally, have PHS patients received proper anticoagulant management in past arthroplasties?

Methods

The National Inpatient Sample (NIS) database for the years between 2003 and 2014 was searched to identify patients undergoing primary TJA. Patients with PHS were identified with the ICD‐9‐CM code 289.81. The χ²‐test, the Pearson test, and adjusted multivariate regression analysis were performed to evaluate the difference and odds ratios between the positive and negative diagnosis groups.

Results

From 2003 to 2014, a total of 2,044,356 patients were identified in the NIS as undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) in the United States. A total of 4664 patients (0.2%) were identified as having PHS. Compared with the non‐PHS group, TJA patients with PHS had a higher risk of DVT (THA: odds ratio [OR] = 8.343, 95% CI: 5.362–12.982, P < 0.001; TKA: OR = 4.712, 95% CI: 3.560–6.238, P < 0.001) but did not have increased risk of PE (THA: OR = 1.306, 95% CI: 0.48–3.555, P = 0.602; TKA: OR = 1.143, 95% CI: 0.687–1.903), and only PHS patients in the THA group had higher risks of inpatient mortality (OR = 3.184, 95% CI: 1.348–7.522, P = 0.008) and periprosthetic joint infection (OR = 3.343, 95% CI: 1.084–10.879, P = 0.036). In addition, PHS patients had extended length of stay, higher total costs, and increased risks of certain other complications, such as peripheral vascular disease, hemorrhage, and thrombophlebitis.

Conclusion

In the present study, PHS patients had higher risks of DVT, greater in‐hospital resource consumption, and certain other perioperative complications. However, PHS was not associated with increased risk of PE in TJA patients in the United States between 2003 and 2014. While potential hazards of PHS have already been recognized, the present study revealed additional concerns and demonstrated that further improvements in the perioperative management of patients with hereditary hypercoagulable disorders are essential.

Does the use of postoperative low-molecular-weight heparin in patients with lung cancer increase tube drainage?

BACKGROUND

The objectives of this study are to assess the chest drainage volumes of patients undergoing anatomic resection of non-small cell lung carcinoma and to determine the safety and effectiveness of administering enoxaparin for thromboprophylaxis.

METHODS

A total of 77 patients were included in the study. A study was conducted on the first group of 42 patients in which enoxaparin prophylaxis (enoxaparin, 40 mg) was subcutaneously injected once a day for a period of three days after the patients underwent anatomic pulmonary resection between March 2016 and March 2018. An enoxaparin-free group was identified and included 35 patients who received no enoxaparin prophylaxis after undergoing anatomic pulmonary resection between February 2013 and February 2016. We compared the changes in hemoglobin (Hb) levels, postoperative 3-day drainage volume, transfusion volume, pulmonary complications and length of stay between the two groups.

RESULTS

No differences in postoperative Hb levels, chest drainage volume, transfusion volume, postoperative complications, and length of stay were observed between the two groups. Deep-vein thrombosis was noted in a patient in the enoxaparin-free group. No major bleeding was noted in either group.

CONCLUSION

We found that for patients undergoing anatomic resection of primary lung cancer, the blood transfusion and chest drainage volumes did not differ, regardless of whether the patients were given enoxaparin. To the best of our knowledge, the impact of low-molecular-weight heparin on chest tube drainage volume for patients undergoing anatomic resection of non-small cell lung carcinoma has not been investigated before.

Postoperative Deep Vein Thrombosis, Pulmonary Embolism, and Myocardial Infarction: Complications After Therapeutic Anticoagulation in the Patient With Spine Trauma

STUDY DESIGN

A retrospective review (2001-2014) was conducted using prospectively collected data at a level I trauma center.

OBJECTIVE

We sought to determine the incidence and characteristics of complications occurring secondary to therapeutic anticoagulation in adult spine trauma patients.

SUMMARY OF BACKGROUND DATA

Numerous studies have assessed prophylactic anticoagulation after spine surgery, but none has investigated the risks of therapeutic doses of anticoagulation for treatment of postoperative thromboembolic events.

METHODS

Patients were included if they sustained a postoperative thromboembolic event (deep venous thrombosis, pulmonary embolism, or myocardial infarction). Patients were excluded if anticoagulation was subtherapeutic. Of 1712 patients, 62 who received therapeutic anticoagulation and 174 propensity-matched control patients who did not receive therapeutic anticoagulation were included in the study.

RESULTS

Initial anticoagulation was obtained by heparin infusion (51%), low-molecular-weight heparin (LMWH, 46%), and warfarin (3%). Complications requiring unplanned reoperation occurred in 18% of anticoagulated patients and 10% of nonanticoagulated patients (P = 0.17). The reoperation rate after heparin infusion was 31% and after LMWH was 6.5% (P = 0.02). Epidural hematoma occurred in 3% and 1% of anticoagulated and nonanticoagulated patients, respectively. Multivariate logistic regression analysis of the two groups showed a trend toward increased risk of reoperation in the anticoagulation group. Analysis of the heparin infusion subgroup separate from the LMWH subgroup compared with the control group showed an increased risk of reoperation for any complication (odds ratio, 3.57; P = 0.01) and for bleeding complications (odds ratio, 43.1; P = 0.01).

CONCLUSION

This is the first study to quantify complications secondary to postoperative therapeutic anticoagulation in spine patients. Postoperative spine trauma patients who underwent therapeutic anticoagulation experienced an unplanned reoperation rate of 18%, including a 3% incidence of spinal epidural hematoma. Therapeutic anticoagulation using heparin infusion seems to drive the overall rate of reoperation (31%) compared with LMWH.

LEVEL OF EVIDENCE

3.

Incidence of deep venous thrombosis following periacetabular and derotational femoral osteotomy: a case for mechanical prophylaxis

There are currently no established guidelines for appropriate antithrombotic prophylaxis following periacetabular osteotomy (PAO) or derotational femoral osteotomy (DFO). The purpose of this study was to determine the incidence of clinical deep venous thrombosis (DVT) following PAO and/or DFO wherein a portable, mechanical device and low-dose aspirin were used postoperatively for DVT prophylaxis. Patients who had undergone staged hip arthroscopy and primary PAO and/or DFO were prospectively reviewed. Following PAO/DFO, patients were prophylactically treated for thromboembolic disease with a portable, mechanical compression device for 3 weeks and low-dose aspirin for 4 weeks. Patients were followed in clinic until 24 months postoperatively. During the study period, 145 hips (124 patients) underwent surgery (PAO: 109, DFO: 24, PAO + DFO: 12). Overall, the incidence of clinically apparent DVT was 0% in the study cohort. Average estimated blood loss during surgery was 601 mL and five cases required blood transfusions of 1 or 2 units. Ten patients were seen in the emergency room 10–20 days after surgery presenting with calf tenderness and DVT was ruled out in all cases with ultrasound. There were no postoperative bleeding or wound complications. A portable, mechanical compression device and low-dose aspirin effectively lessens the risk of DVT following staged hip arthroscopy and PAO/DFO without an increased risk of bleeding complications.

Topical Tranexamic Acid Reduces Blood Loss in Minimally Invasive Total Knee Arthroplasty Receiving Rivaroxaban

Background

It is unclear whether topical (intra-articular) or intravenous TXA reduces blood loss in minimally invasive TKA patients receiving a direct oral anticoagulant for thromboprophylaxis. This study is to investigate whether TXA given intravenously or intra-articularly is effective in reducing blood loss in minimally invasive TKA patients using rivaroxaban for thromboprophylaxis.

Methods

Ninety-three patients who underwent primary minimally invasive TKA were divided into placebo group (30 patients) that received saline both intravenously and intra-articularly, intravenous (IV) group (31 patients) that received 1 g TXA intravenously, and topical group (32 patients) that received 3 g TXA in 100 ml saline intra-articularly. All patients received oral rivaroxaban of 10 mg daily for 14 days postoperatively.

Results

p < 0.001 and p = 0.041. The mean total blood loss was 1131 mL (567–1845) in placebo, which was higher than that in the IV group (921 mL; range, 465–1495; p = 0.014) and the topical group (795 mL; range, 336–1350; p < 0.001). The total blood loss did not differ between the IV and the topical group (p = 0.179).

Conclusion

This prospective, randomized, controlled trial demonstrated an equal efficacy of TXA in blood conservation when administered intravenously or topically in minimally invasive TKA patients receiving rivaroxaban for thromboprophylaxis.

Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis - A 12year study

BACKGROUND

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital.

METHODS

We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results.

RESULTS

The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE's occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%).

CONCLUSIONS

Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.

The Efficacy of Combined Use of Rivaroxaban and Tranexamic Acid on Blood Conservation in Minimally Invasive Total Knee Arthroplasty a Double-Blind Randomized, Controlled Trial

BACKGROUND

Tranexamic acid (TXA) was reportedly to decrease postoperative blood loss after standard total knee arthroplasty (TKA). However, the blood-conservation effect of TXA in minimally invasive TKA, in particular, receiving a direct oral anticoagulant was unclear. The aim of the study was to investigate the efficacy of combined use of TXA and rivaroxaban on postoperative blood loss in primary minimally invasive TKA.

METHODS

In a prospective, randomized, controlled trial, 198 patients were assigned to placebo (98 patients, normal saline injection) and study group (100 patients, 1g TXA intraoperative injection) during primary unilateral minimally invasive TKA. All patients received rivaroxaban 10 mg each day for 14 doses postoperatively. Total blood loss was calculated from the maximum hemoglobin drop after surgery plus amount of transfusion. The transfusion rate and wound complications were recorded in all patients. Deep-vein thrombosis was detected by ascending venography of the leg 15 days postoperatively.

RESULTS

The mean total blood loss was lower in the study group (1020 mL [95% confidence interval, 960-1080 mL]) compared with placebo (1202 mL [95% confidence interval, 1137-1268 mL]) (P < .001). The transfusion rate was lower in the study group compared with placebo (1% vs 8.2%, P = .018). Postoperative wound hematoma and ecchymosis were higher in placebo than the study group (P = .003). There was no symptomatic deep-vein thrombosis or pulmonary embolism in either group.

CONCLUSION

Systemic administration of TXA can effectively reduce the postoperative blood loss which results in lower rate of transfusion requirement and wound hematoma in minimally invasive TKA patients when rivaroxaban is used for thromboprophylaxis. Rivaroxaban has a high rate of bleeding complications when used alone in TKA patients.

Rate of Transfusions After Total Knee Arthroplasty in Patients Receiving Lovenox or High-Dose Aspirin

BACKGROUND

Controversy continues regarding the use of powerful anticoagulants for venous thromboembolism prophylaxis in patients undergoing total knee arthroplasty (TKA). To comply with institution-mandated guidelines and pressure from hospitalist intent on complying with conventionally recommended anticoagulation guidelines, we singularly changed our chemoprophylaxis practice from using aspirin to Lovenox and noted that transfusion rates increased substantially.

METHODS

A retrospective case review was performed to evaluate transfusion requirement differences in primary TKA patients receiving Lovenox (unilateral TKA: n = 135, bilateral TKA: n = 44) or aspirin (unilateral TKA: n = 153, bilateral TKA: n = 45) for venous thromboembolism prophylaxis. Pearson's chi-square tests were used to evaluate surgical complications and the rate of transfusions between aspirin and Lovenox groups. Independent t tests were used to evaluate the units of packed red blood cells transfused, hemoglobin drop, and hematocrit drop between aspirin and Lovenox groups.

RESULTS

Lovenox was found to significantly increase (P < .01) the rate of transfusion, units of packed red blood cells, hemoglobin drop, and hematocrit drop compared to aspirin in both unilateral and bilateral TKA patients, without significantly decreasing venous thromboembolism events (aspirin: 3 pulmonary embolisms and 4 deep venous thrombosis; Lovenox: 3 pulmonary embolisms and 2 deep venous thrombosis).

CONCLUSION

Our findings suggest that aspirin is as effective as Lovenox in preventing venous thromboembolism and that the use of Lovenox significantly increases the likelihood of requiring transfusions after surgery.

Efficacy of preoperative administration of single high dose intravenous tranexamic acid in reducing blood loss in total knee arthroplasty: A prospective clinical study

Objective

The aim of this study was to analyse the effectiveness of single dose of 20 mg/kg intravenous tranexamic acid (TXA), in reducing the blood loss in patients undergoing total knee arthroplasty (TKA).

Material and method

70 patients (65.5 ± 8.1 years old) that have undergone TKA were divided in two groups. The 20 mg/kg IV TXA was given before the skin incision to one group (study group). On the control group, TKA was performed without TXA. The demographic data, body mass index, amount of bleeding and erythrocyte infusion during the operation, hemoglobin and hematocrit values (preoperative and 48th hour), the amount of drainage after the operation were compared between the groups.

Results

The total amount of bleeding in the study group was 634.03 ± 182.88 ml and 1166.42 ± 295.92 ml in the control group (p < 0.001). Perioperative bleeding was 252.01 ± 144.13 ml in the study group and 431.33 ± 209.10 ml in the control group (p = 0.018). The drainage after the operation was 311.11 ± 141.64 ml at the 24th hour in the study group, 640.74 ± 279.43 ml at the 24th hour in the control group (p < 0.001). The drainage after 24th hour was 97.96 ± 115.86 ml in the study group and 112.96 ± 64.43 ml in the control group (p = 0.584).

Conclusion

A high, single dose of TXA intravenously given to the patient prior to the TKA significantly reduces the bleeding during the operation and within the postoperative 24 h. There is no significant change in the bleeding amount after the 24th hour following the operation.

Fatal pulmonary embolism following elective total hip arthroplasty

Aims

The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime.

Patients and Methods

A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death.

Results

During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction.

Conclusion

We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8.

Thromboembolic disease after knee arthroplasty is rare in Southern Iran

BACKGROUND

Thromboembolic disease (TED) after knee arthroplasty occurs infrequently in Iran. The aim of this study was to examine the incidence of TED in patients with osteoarthritis undergoing knee replacement in Southern Iran while on prophylaxis.

MATERIALS & METHODS

In a case series study from January to December 2012, 100 consecutive total knee arthroplasty (TKA) candidates were evaluated for TED by clinical evaluation and Doppler sonography preoperatively and 2 months postoperatively and by clinical evaluation one year after surgery. The patients in this study randomly received either warfarin or enoxaparin prophylactically.

RESULTS

A total of 77 women and 23 men with mean age of 67 years (52-82 years) entered the study. The average hemoglobin drop of 2.7 g with warfarin and 3.3 with enoxaparin was observed. No case of TED, pulmonary embolus (PE), major bleeding, post-thrombotic syndrome, or hemarthrosis was observed.

CONCLUSION

No clinically significant DVT was found using either enoxaparin or warfarin prophylaxis after TKA in Southern Iran. Relatively excessive postoperative bleeding was observed, particularly with enoxaparin.

Impact of thromboprophylaxis across the US acute care setting

Background

The risk of venous thromboembolism (VTE) can be reduced by appropriate use of anticoagulant prophylaxis. VTE prophylaxis does, however, remain substantially underused, particularly among acutely ill medical inpatients. We sought to evaluate the clinical and economic impact of increasing use of American College of Chest Physicians (ACCP)-recommended VTE prophylaxis among medical inpatients from a US healthcare system perspective.

Methods and Findings

In this retrospective database cost-effectiveness evaluation, a decision-tree model was developed to estimate deaths within 30 days of admission and outcomes attributable to VTE that might have been averted by use of low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH). Incremental cost-effectiveness ratio was calculated using “no prophylaxis” as the comparator. Data from the ENDORSE US medical inpatients and the US nationwide Inpatient Sample (NIS) were used to estimate the annual number of eligible inpatients who failed to receive ACCP-recommended VTE prophylaxis. The cost-effectiveness analysis indicated that VTE-prevention strategies would reduce deaths by 0.5% and 0.3%, comparing LMWH and UFH strategies with no prophylaxis, translating into savings of $50,637 and $25,714, respectively, per death averted. The ENDORSE findings indicated that 51.1% of US medical inpatients were at ACCP-defined VTE risk, 47.5% of whom received ACCP-recommended prophylaxis. By extrapolating these findings to the NIS and applying cost-effectives analysis results, the full implementation of ACCP guidelines would reduce number of deaths (by 15,875 if using LMWH or 10,201 if using UFH), and was extrapolated to calculate the cost reduction of $803M for LMWH and $262M for UFH.

Conclusions

Efforts to improve VTE prophylaxis use in acutely ill inpatients are warranted due to the potential for reducing VTE-attributable deaths, with net cost savings to healthcare systems.

DVT prophylaxis after TKA: routine anticoagulation vs risk screening approach - a randomized study

The American College of Chest Physicians (ACCP) recommended routine anticoagulation for thromboprophylaxis in patients undergoing lower limb arthroplasty. We compared results of routine anticoagulation Vs risk stratified approach for Deep Venous Thrombosis (DVT) prophylaxis after TKA in terms of symptomatic DVT and wound complications. Nine hundred TKAs done in 673 patients were randomized after DVT risk screening to routine anticoagulation (n = 450) or to risk stratification (n = 450) and selective anticoagulation. 194 patients in the risk screening group received only Aspirin. Primary outcome was symptomatic DVT and wound complication. This randomized study showed that the symptomatic DVT rates after TKA were similar whether patients were routinely anticoagulated or selectively anticoagulated after risk screening. However there was a significantly higher incidence of wound complications (P < 0.014) after routine anticoagulation.

Three-in-one nerve block with different concentrations of bupivacaine in total knee arthroplasty: randomized, placebo-controlled, double-blind trial

Pain after total knee arthroplasty may be severe and lead to adverse outcomes. Using 2 concentrations of bupivacaine, we investigated 3-in-1 nerve block's effect on pain control, narcotic use, sedation, and patient satisfaction. One hundred five patients undergoing unilateral total knee arthroplasty were randomized into 3 groups: low-dose or high-dose bupivacaine or placebo. Ninety-nine patients completed the study. Three-in-1 nerve block reduced patient-controlled opioid analgesia usage and improved pain relief in the early postoperative period but had little effect beyond postoperative day 1. There were no significant differences among groups with respect to nausea or sedation. Patients in each group exhibited high overall satisfaction. Low-dose bupivacaine was superior to high-dose bupivacaine for pain relief, narcotic consumption, and patient satisfaction in the early postoperative period.

Early postoperative hemorrhage after first rib resection for vascular thoracic outlet syndrome

BACKGROUND

Thrombosis and embolization are the most frequent complications associated with the vascular presentation of thoracic outlet syndrome (VTOS). Therefore, surgery for these conditions requires careful balancing of anticoagulation and hemostasis. Our goal is to identify the optimal postoperative anticoagulation management of these patients.

METHODS

A prospective database of consecutive patients who have presented to our institution with the diagnosis of thoracic outlet syndrome was reviewed from 1996 through 2010 for instances of postoperative hemorrhage. All venous cases were managed with transaxillary first rib resection followed by postoperative venography and percutaneous angioplasty when required. All arterial cases first underwent thrombolysis, then decompression with transaxillary first and cervical rib resection with concomitant arterial repair when indicated.

RESULTS

Over the study period, 423 patients diagnosed with thoracic outlet syndrome underwent 551 procedures. Of these, 108 presented with VTOS (12 arterial and 96 venous). Mean age of the patients in the cohort was 33.7 ± 11.5 years, with 53 women and 55 men. Postoperative hemorrhage occurred in four patients (4%): three venous cases and one arterial case. Three patients required tube thoracostomy (average blood return: 800 mL) and two required video-assisted thoracoscopic surgery for decortication. Age, gender, preoperative anticoagulation, interval from thrombolysis to surgery, operative duration, and operative blood loss had no effect on the risk of bleeding. No hemorrhage occurred in patients treated with postoperative coumadin alone (82 patients) or with no anticoagulant (24 patients). The four cases of hemorrhage occurred only in patients treated with postoperative low-molecular-weight heparin (LMWH; 14 patients; p < 0.01).

CONCLUSION

Postoperative hemorrhage was not a common complication of first rib resection for VTOS. In our experience, it occurred exclusively in patients receiving LMWH postoperatively. Postoperative LMWH should be used with caution in patients with VTOS.

Deep vein thrombosis after total knee arthroplasty in asian patients without prophylactic anticoagulation

Deep vein thrombosis (DVT) is an important complication following total knee arthroplasty (TKA). However, the incidence of DVT is generally underestimated due to subclinical or minor symptoms and signs. In Western countries, prophylactic agents against DVT are administered routinely after TKA. However, in Asia, no regular prophylaxis is generally given to patients undergoing TKA. This article presents a prospective study evaluating the incidence of DVT in 724 consecutive Taiwanese patients who underwent TKA without prophylactic anticoagulation therapy. Of these, 328 patients (45.3%) showed positive Homan's sign with calf swelling >3 cm. Ultrasonographic examination revealed the overall incidence of DVT to be 8.6% (62/724). The incidence of DVT was significantly higher in women (P=.035), in patients who underwent bilateral TKA (P=.002), and in patients with a body mass index ≥30 kg/m(2) (P=.026). The incidence of DVT appeared to be increased in patients with higher tourniquet time; however, the difference was not statistically significant. In all of the suspected cases of DVT, the symptoms subsided after the administration of enoxaparin with uneventful follow-up. No patient developed pulmonary embolism. Our results showed a relatively high incidence of DVT in an Asian population following TKA. We therefore consider that following TKA, prophylactic anticoagulation therapy should be administered to high-risk patients.

The monitoring of heparin induced thrombocytopenia following surgery: an audit and international survey

Heparin-induced thrombocytopenia (HIT) is a serious postoperative complication of low-molecular-weight heparin (LWMH) prescribed following surgery and recent evidence based guidelines recommend routine platelet count monitoring for all at-risk patients. With the implementation of these guidelines this clinical study demonstrated a significant improvement (2-56% p < 0.05) in HIT diagnosis in postoperative patients receiving LMWH. An international survey showed a lack of awareness of heparin-induced thrombocytopenia and its management.

Monitoring and management of heparin-induced thrombocytopenia

Low molecular weight heparins have been used to reduce thromboembolic risk for at least 20 years, but their use is not without risk. This article considers the incidence, monitoring, treatment and lack of insight about heparin-induced thrombocytopenia - a potentially fatal complication of low molecular weight heparin use.

High incidence of complications from enoxaparin treatment after arthroplasty

Pulmonary embolism (PE) complicates 1% to 10% of total joint arthroplasties and generally requires immediate anticoagulation. Low-molecular-weight heparins have supplanted unfractionated heparin as the treatment of choice for PE and hold a 1A recommendation from the American College of Chest Physicians for this indication. However, the complications of enoxaparin treatment begun in close proximity to arthroplasty surgery are not well described. We examined the records of 135 patients who underwent total joint arthroplasty, experienced an in-hospital PE, and received treatment with enoxaparin at therapeutic doses (1 mg/kg body weight). The type and frequency of complications were determined and classified as major or minor. Twenty-seven percent of patients experienced minor complications and 10% experienced major complications. The incidence of major bleeding was substantially higher than rates reported for nonsurgical patients. The overall complication rate of enoxaparin treatment is similar to the rate of complications reported for unfractionated heparin treatment in this setting, but the complications are less severe.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Evaluating the effectiveness of a deep-vein thrombosis prophylaxis protocol in orthopaedics and traumatology

RATIONALE, AIMS AND OBJECTIVES

To evaluate the effectiveness of the deep-vein thrombosis (DVT) prophylaxis protocol for adult patients in a general orthopaedics and traumatology clinic.

METHOD

We followed the DVT prophylaxis protocol in 1326 (776 female, 550 male) of 2114 adult patients admitted to the Department of Orthopaedics and Traumatology in Goztepe Research and Training Hospital. They were followed for symptomatic DVT and possible complications of low-molecular-weight heparin (LMWH) therapy. A Doppler ultrasonography (US) was performed when DVT was suspected. The medical information treatment protocols of DVT patients were recorded.

RESULTS

Doppler US was performed in 58 patients with suspected DVT. Six of these patients were diagnosed with DVT. The side effects of LMWH were upper gastrointestinal bleeding (0.5%), widespread ecchymosis of the extremities (1.9%) and heparin-induced thrombocytopenia (0.16%).

CONCLUSION

Symptomatic DVT occurrences were similar to those in medical literature; however, there were fewer side effects of LMWH than reported in literature.

Thromboembolic prophylaxis for total knee arthroplasty in Asian patients: a randomised controlled trial

PURPOSE

To compare the efficacy and safety of different modes of thromboembolic prophylaxis for elective total knee arthroplasty (TKA) in Asian patients.

METHODS

440 low-risk patients undergoing TKA were randomised into 4 equal groups: (1) no prophylaxis (control), (2) graduated compression stockings (GCS), (3) intermittent pneumatic compression (IPC), and (4) low-molecular-weight heparin (enoxaparin). Duplex ultrasonography was used as an assessment tool.

RESULTS

The deep vein thrombosis point prevalence was highest in the control group (22%), which was significantly higher than in patients receiving IPC (8%, p=0.032) or enoxaparin (6%, p=0.001). One patient each in the control and GCS groups developed a non-fatal pulmonary embolism. Patients on enoxaparin received more blood transfusions and 2 of them had major bleeding complications.

CONCLUSION

IPC is the preferred method of thromboprophylaxis for TKA in Asian patients.

Potent anticoagulants are associated with a higher all-cause mortality rate after hip and knee arthroplasty

Anticoagulation for thromboprophylaxis after THA and TKA has not been confirmed to diminish all-cause mortality. We determined whether the incidence of all-cause mortality and pulmonary embolism in patients undergoing total joint arthroplasty differs with currently used thromboprophylaxis protocols. We reviewed articles published from 1998 to 2007 that included 6-week or 3-month incidence of all-cause mortality and symptomatic, nonfatal pulmonary embolism. Twenty studies included reported 15,839 patients receiving low-molecular-weight heparin, ximelagatran, fondaparinux, or rivaroxaban (Group A); 7193 receiving regional anesthesia, pneumatic compression, and aspirin (Group B); and 5006 receiving warfarin (Group C). All-cause mortality was higher in Group A than in Group B (0.41% versus 0.19%) and the incidence of clinical nonfatal pulmonary embolus was higher in Group A than in Group B (0.60% versus 0.35%). The incidences of all-cause mortality and nonfatal pulmonary embolism in Group C were similar to those in Group A (0.4 and 0.52, respectively). Clinical pulmonary embolus occurs despite the use of anticoagulants. Group A anticoagulants were associated with the highest all-cause mortality of the three modalities studied.

The 2007 ABJS Nicolas Andry Award: three decades of clinical, basic, and applied research on thromboembolic disease after THA: rationale and clinical results of a multimodal prophylaxis protocol

Total hip arthroplasty is an operation with a high risk for venous thromboembolism. Three decades of research conducted at the Hospital for Special Surgery identified the exact timing of the thrombogenic stimulus during surgery, defined the role of magnetic resonance venography, and established the role of certain genetic and acquired predispositions. Based on these studies, we implemented a multimodal prophylaxis consisting of a series of safe preventive measures applied before, during, and immediately after surgery to reduce the risk of venous thromboembolism. If these safe preventive measures are strictly observed, postoperative pharmacologic prophylaxis does not need to be aggressive in the patient without predisposing factors who mobilizes promptly, thus diminishing the risk of bleeding associated with the use of anticoagulants and the overall cost of care. Our clinical experience with more than 5000 total hip arthroplasties performed during the last decade and closely followed prospectively for a minimum of 3 months clearly shows this multimodal prophylaxis is safe and effective resulting in a very low prevalence of thromboembolism.

Thromboembolic disease after total hip arthroplasty: who is at risk?

The strong activation of the clotting cascade that occurs during total hip arthroplasty places patients at increased risk for venous thromboembolism. The risk is higher in those patients with the following predisposing factors, listed in approximate order of importance: hip fracture; malignancy, particularly if associated with chemotherapy; antiphospholipid syndrome; immobility; history of venous thromboemholism; administration of tamoxifen; raloxifene; oral contraceptives or estrogen; morbid obesity; stroke; atherosclerosis; and an American Society of Anesthesiologists physical status classification of 3 or greater. The following risk factors are weak or controversial: advanced age; diabetes mellitus; congestive heart disease; atrial fibrillation; varicose veins; and smoking. However, 50% of patients who develop thromboembolism after total hip arthroplasty have no clinical predisposing factors. In a matched, controlled study, we defined the major genetic predispositions that increase the risk of venous thromboembolism after total hip arthroplasty: deficiency of antithrombin III (< 75%) and protein C (< 70%), and prothrombin gene mutation. Preoperative genetic screening in conjunction with the recognized clinical risk factors can help categorize postoperative venous thromboembolism risk and differentiate patients who can be protected with milder and safer prophylaxis (eg, aspirin, intermittent pneumatic compression) compared with those at higher risk who need to be anticoagulated.

The benefit of aspirin chemoprophylaxis for thromboembolism after total knee arthroplasty

The threat of thromboembolic events after total knee arthroplasty has been substantially reduced during the past decade. Currently, the risk of fatal pulmonary embolism is approximately 0.1%. This is due to a confluence of changes in our medical practices, including early mobilization, less traumatic surgery, increased use of regional anesthesia, pneumatic compression devices, and chemoprophylactic agents. Because many chemoprophylactic agents are associated with an increased risk of bleeding, we have chosen aspirin as our preferred method of chemoprophylaxis. This study seeks to determine if aspirin is as effective as newer chemoprophylactic agents as judged by the prevalence of fatal or nonfatal pulmonary embolus, readmission for deep venous thrombosis, and risk of bleeding. Aspirin was the principle chemoprophylactic agent for 3473 consecutive patients having total knee arthroplasty. All patients were followed for a minimum of 6 weeks. There were nine deaths: two from pulmonary embolism, five cardiac events, one stroke, and one fat embolism. Three cardiac-related deaths occurred in patients for whom pulmonary embolism could not definitively be ruled out. Therefore, the best case and worst case scenarios for fatal pulmonary embolism were 0.06% and 0.14%, respectively. Thirteen patients underwent reoperation for hematoma (0.4%). Therefore, we have demonstrated aspirin combined with early mobilization, regional anesthesia, foot pumps, and improved surgical techniques is safer than and equally efficacious as other chemoprophylaxis agents.

VenaFlow plus Lovenox vs VenaFlow plus aspirin for thromboembolic disease prophylaxis in total knee arthroplasty

Two hundred seventy-five patients undergoing unilateral total knee arthroplasty were prospectively randomized to receive spinal epidural anesthesia (SEA), a VenaFlow calf compression device, and enoxaparin (group A) or SEA, VenaFlow, and aspirin (group B). Aspirin was started on the day of surgery, whereas enoxaparin was started 48 hours after surgery. Anticoagulants were continued for 4 weeks after surgery. All patients had an in-hospital ultrasound screening test on postoperative days 3 to 5 and a second follow-up ultrasound 4 to 6 weeks after surgery. The overall deep venous thrombosis rates in groups A and B were 14.1% and 17.8% (P = not significant), respectively. When used in combination with pneumatic compression devices and SEA, enoxaparin was not superior to aspirin in preventing deep venous thrombosis after total knee arthroplasty.

Venous thromboembolism is rare with a multimodal prophylaxis protocol after total hip arthroplasty

We evaluated the safety and efficacy of a multimodal approach for prophylaxis of thromboembolism after total hip arthroplasty, which includes preoperative discontinuation of procoagulant medication; autologous blood donation; hypotensive epidural anesthesia; intravenous administration of heparin during surgery and before femoral preparation; aspiration of intramedullary contents; pneumatic compression; knee-high elastic stockings; and early mobilization and chemoprophylaxis for 4 to 6 weeks (aspirin 83%; warfarin 17%). One thousand nine hundred forty-seven consecutive, nonselected patients (2032 total hip arthroplasties) who received this multimodal prophylaxis were observed prospectively for 3 months. The incidence of asymptomatic deep vein thrombosis assessed by ultrasound in the first 171 patients was 6.4%. The incidence of clinical deep vein thrombosis in the subsequent 1776 patients was 2.5%. Symptomatic pulmonary embolism occurred in 0.6% (12 of 1947; nine in patients receiving aspirin and three in patients receiving Coumadin), none of them fatal. One patient died of a myocardial infarct. This multimodal approach is safe and efficacious and compares favorably with those reported in the literature and with our historic controls. If these preventive measures are strictly observed during the perioperative period, postoperative chemoprophylaxis does not need to be aggressive in the patient without predisposing factors. Our low rate of deep vein thrombosis and pulmonary embolism do not support routine anticoagulation prophylaxis with drugs that increase risk of bleeding.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Flexibility in administration of fondaparinux for prevention of symptomatic venous thromboembolism in orthopaedic surgery

Venous thromboembolism (VTE) is a common complication of total joint arthroplasty. Fondaparinux VTE prophylaxis is currently begun 6 to 8 hours after surgery. Flexible dosing may reduce bleeding risk and allow easier use by starting the morning after surgery instead of staggered hours on the surgery day. This study examined flexible timing of the first dose of fondaparinux. Whether the first dose was administered 8 +/- 2 hours after surgery or the morning after surgery, no significant difference was observed in incidence of symptomatic VTE (2.0% and 1.9%, respectively, P = .89). Major and minor bleeding events were similar between groups (1.2% and 0.7% [P = .19], and 1.4% and 2.0% [P = .31], respectively). Delaying initiation of fondaparinux prophylaxis provides an option after total joint arthroplasty with preserved efficacy and safety.

The John Charnley Award: heritable thrombophilia and development of thromboembolic disease after total hip arthroplasty

We retrospectively assessed whether heritable thrombophilia-hypofibrinolysis was more common in patients developing venous thromboembolism after total hip replacement than among control patients who did not develop venous thromboembolism, as an approach to better identify causes of venous thromboembolism after total hip arthroplasty. Twenty patients with proximal deep venous thrombosis after THA and 23 patients with symptomatic pulmonary embolism were compared with 43 control patients who did not have postoperative venous thromboembolism. Five of 42 patients with venous thromboembolism (12%) and 0 of 43 control patients (0%) had antithrombin III deficiency (< 75%). Nine of 42 patients with venous thromboembolism (21%) and 2 of 43 control patients (4.7%) had protein C deficiency (< 70%). Ten of 43 patients with venous thromboembolism (9 heterozygous, 1 homozygous; 23%) and 1 of 43 control patients (heterozygous; 2%) had the prothrombin gene mutation. Patients who had venous thromboembolism after total hip arthroplasty were more likely than matched control patients to have heritable thrombophilia with antithrombin III or protein C deficiency, or homo-heterozygosity for the prothrombin gene mutation. Screening for these three tests of heritable thrombophilia before total hip arthroplasty should improve the identification of patients with a reduced risk of venous thromboembolism who may need only mild thromboprophylaxis, and of those patients with heritable thrombophilia in whom prophylaxis should be more aggressive.

LEVEL OF EVIDENCE

Prognostic study, Level II-1 (lesser-quality RCT). See the Guidelines for Authors for a complete description of levels of evidence.

Spontaneous spinal subdural hematoma associated with low-molecular-weight heparin. Case report

Spinal subdural hematomas (SDHs) are a rare cause of cord compression and typically occur in the setting of spinal instrumentation or coagulopathy. The authors report the first case of a spontaneous spinal SDH occurring in conjunction with low-molecular-weight heparin use in a patient with a history of spinal radiotherapy.

Deep venous thrombosis prophylaxis: better living through chemistry--in opposition

The best prophylactic regimens for thromboembolic disease continue to be debated despite years of investigation. The surgeon must balance the clinical risks and benefits. A decision depends on accurate data and our ability to balance the risks of fatal pulmonary embolism (PE) to the risk of bleeding. The current risk for fatal PE is 0.1% with most current prophylactic regimes. The risk of perioperative bleeding increases 1.8% to 5.2% with low molecular weight heparins or warfarin and generally is dose dependent. Most of the current prophylactic recommendations are based on the presence or absence of deep venous thrombosis (DVT). However, the correlation between the presence of a DVT and the risk of PE is low and inconsistent. Therefore, DVT may not be an accurate surrogate marker for the patient at risk after total joint surgery. Our experience with 2800 consecutive total knee arthroplasty patients, using aspirin as our principle agent, shows a fatal PE risk of 0.1% and a low risk of bleeding. Therefore, our current recommendation is aspirin.

VENOUS THROMBOSIS PROPHYLAXIS FOR UROLOGICAL LAPAROSCOPY: FRACTIONATED HEPARIN VERSUS SEQUENTIAL COMPRESSION DEVICES

PURPOSE

Venous thromboembolism (VTE) is a significant postoperative complication. Common methods of VTE prophylaxis include subcutaneous fractionated heparin (FH) and lower extremity sequential compression devices (SCD). There is no conclusive evidence supporting 1 method compared to the other for urological laparoscopy. We examined the rates of postoperative hemorrhagic and thrombotic complications after laparoscopic urological procedures in patients treated with FH or SCD as VTE prophylaxis.

MATERIALS AND METHODS

A prospective database augmented by retrospective chart review included all patients who underwent urological laparoscopic surgery of the upper retroperitoneum at our institution from June 2000 to December 2002. Patients nonrandomly received FH or SCD as VTE prophylaxis beginning on the day of surgery.

RESULTS

A total of 344 patients were included in this study, 172 in the FH group and 172 in the SCD group. Thrombotic complications included VTE and/or pulmonary embolism. Hemorrhagic complications were minor or major, the latter requiring transfusion or other intervention. In both groups the rate of thrombotic complication was 2 of 172 (1.2%). The rate of hemorrhagic complication was 16 of 172 (9.3%) in the FH group, of which 12 of 172 (7.0%) were major. The hemorrhagic complication rate was 6 of 172 (3.5%), with 5 of 172 (2.9%) being major in the SCD group.

CONCLUSIONS

After urological laparoscopy of the upper retroperitoneum, subcutaneous fractionated heparin is associated with increased hemorrhagic complications (p = 0.045), without a reduction in thrombotic complications (p >0.999), compared with sequential compression devices.

Major bleeding rates after prophylaxis against venous thromboembolism: Systematic review, meta-analysis, and cost implications

Objectives: The frequency and consequences of major bleeding associated with anticoagulant prophylaxis for prevention of venous thromboembolism is examined.

Methods: We conducted a systematic review and meta-analysis of controlled trials that reported rates of major bleeding after pharmaceutical thromboprophylaxis in patients undergoing major orthopedic surgery. Thromboprophylactic agents were divided into four groups:warfarin/other coumarin derivatives (WARF), unfractionated heparin (UFH), low molecular weight heparin (LMWH), and pentasaccharide (PS). Meta-analysis was conducted comparing LMWH with each of WARF, UFH, and PS. The frequency of re-operation due to major bleeding was reviewed and combined with published costs to estimate the mean cost of managing major bleeding events in these patients.

Results: Twenty-one studies including 20,523 patients met inclusion criteria for the meta-analysis. No evidence of significant between-trial heterogeneity in risk ratios was found. Combined (fixed effects) relative risks (RR) of major bleeding compared with LMWH were WARF – RR 0.59 (95 percent confidence interval [CI], 0.44–0.80); UFH – RR 1.52 (95 percent CI, 1.04–2.23); PS – RR 1.52 (95 percent CI, 1.11–2.09). Seventy-one studies including 32,433 patients were included in the review of consequences of major bleeding. We estimated that the average cost of major bleeding is $113 per patient receiving thromboprophylaxis.

Conclusions: LMWH results in fewer major bleeding episodes than UFH and PS but more than WARF. These events are costly and clinically important.

Risk factors for pulmonary emboli after total hip or knee arthroplasty

Because it is difficult to predict which patients may sustain a pulmonary embolism after total hip or knee arthroplasty, we assessed multiple thrombophilic and hypofibrinolytic parameters to identify risk factors. Twenty-nine patients who survived a known pulmonary embolism after total knee or total hip arthroplasty were matched by age, gender, race, arthritic diagnosis, procedure, and surgery date with 29 patient-controls who had a total hip or knee arthroplasty but who did not have a symptomatic known pulmonary embolism or deep vein thrombosis. Twenty-one serologic measures and five genes associated with thrombophilia, hypofibrinolysis, or both were assessed without knowledge of group assignment. All patients with pulmonary embolism had at least one abnormality of plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, or total cholesterol versus 13 of 27 (48%) control patients. Forty-seven percent of patients who experienced pulmonary embolism had at least two abnormalities of plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, or total cholesterol, versus 7% of control patients. Preoperatively, to identify patients at high risk of pulmonary embolism, plasminogen activator inhibitor activity, dilute Russell's viper venom time, prothrombin time, and cholesterol levels were most predictive. Using at least one abnormality of these four measures as a screening test to detect risk of pulmonary embolism, the test is sensitive (100%), and the predictive value of a negative test is high (100%). After additional prospective study, this may allow identification of patients at low risk (the majority of patients) in whom anticoagulation may not be required and a small group of patients at high risk for pulmonary embolism in whom prophylactic anticoagulation should be provided.

The management of anticoagulants in the periendoscopic period for patients with atrial fibrillation: a decision analysis

PURPOSE

The management of patients who undergo endoscopy while being treated with warfarin is challenging. We used decision analysis to determine the preferred strategy to manage anticoagulants in the periendoscopic period.

METHODS

We designed a Markov model to estimate costs and quality-adjusted survival during a 10-year period in patients with nonvalvular atrial fibrillation undergoing screening colonoscopy. We compared six alternatives to the continue-warfarin strategy, which was to perform colonoscopy while the patient was taking full-dose warfarin. The hold-warfarin strategy was to stop warfarin 5 days before the colonoscopy. The repeat endoscopy strategy was to continue warfarin for a diagnostic colonoscopy, followed by a repeat procedure after cessation of warfarin if polypectomy was required. The dose-reduction strategy was to reduce the warfarin dose before colonoscopy. The low molecular weight heparin strategy was to administer subcutaneous low molecular weight heparin for 2 days before and 2 days after colonoscopy. The unfractionated heparin strategy was to administer intravenous unfractionated heparin for 2 days before and 2 days after the procedure. The vitamin K strategy was to hold warfarin for 4 days and to administer vitamin K if the international normalized ratio (INR) exceeded 2.0 the day before the procedure, or low molecular weight heparin if the INR was less than 1.5.

RESULTS

For screening colonoscopy, assuming that polyps would be removed in 35% of examinations, the hold-warfarin and dose-reduction arms were both cost-effective strategies. The hold-warfarin arm was most cost-effective if the likelihood of polypectomy exceeded 60%, or if there was a low risk of stroke despite atrial fibrillation. The continue-warfarin strategy was preferred if the probability of polypectomy was 1% or less.

CONCLUSION

Temporary warfarin cessation or halving the warfarin dose for several days before endoscopy was the preferred strategy for most patients. Periendoscopic heparin therapy was not cost-effective for patients with nonvalvular atrial fibrillation.

Risks associated with blood transfusion after total knee arthroplasty

A retrospective study of 1,402 patients who underwent primary total knee arthroplasty (TKA) (1,194 unilateral, 208 bilateral) was performed. The strongest predictors for allogenic transfusion after surgery were advancing age (P<.001), low preoperative hemoglobin (P<.001), and the use of low-molecular-weight heparin postoperatively (P<.01). Pre-donation of 1 unit of autologous blood before TKA decreased the allogenic transfusion rate from a baseline of 38% to 11%, whereas pre-donating 2 units lowered the rate of breakthrough transfusion of allogenic blood to 7%. A patient with a preoperative hemoglobin >150 g/L or who is younger than age 65 with a preoperative hemoglobin >130 g/L may not benefit from pre-donation, and a high rate of wastage may result.

The clinical spectrum of retroperitoneal hematoma in anticoagulated patients

Bleeding into the retroperitoneal space is a serious complication of anticoagulation. The incidence may be on the rise due to the increasing number of patients prescribed anticoagulants for atrial fibrillation and other disorders. The clinical manifestations vary from leg paresis to abdominal pain or a catastrophic shock. Thus, an adequate index of suspicion is needed to reverse anticoagulation rapidly and initiate other therapeutic measures. We reviewed the cases diagnosed at our institution and reported in the literature to delineate the clinical manifestations and course of this process.

The COX-2 specific inhibitor, valdecoxib, is an effective, opioid-sparing analgesic in patients undergoing total knee arthroplasty

This multicenter, randomized, double-blind, placebo-controlled study evaluated the analgesic efficacy and opioid-sparing effects of valdecoxib, a potent COX-2 specific inhibitor, in patients undergoing knee replacement. Patients received morphine by patient-controlled analgesia (PCA), and valdecoxib 40 mg or 80 mg daily, or placebo, for up to two days. Efficacy was assessed by the cumulative amount of morphine administered over 48 hours, pain intensity and patient's evaluation of medication. Morphine consumption over 48 hours by patients receiving valdecoxib 40 mg or 80 mg daily plus morphine was 83.7% and 75.8% (P < 0.05) of the total amount consumed by patients receiving morphine alone. Patients receiving valdecoxib 40 mg and 80 mg daily experienced significantly lower maximum pain intensity on Day 2 (P < 0.05), and rated their study medication significantly higher than patients receiving morphine alone. Valdecoxib plus morphine was well tolerated. Thus, valdecoxib in combination with morphine provides multi-modal analgesia that reduces pain and opioid use and increases patient satisfaction following knee replacement surgery.

The effect of anticoagulation on the restoration of range of motion after total knee arthroplasty: enoxaparin versus aspirin

Anticoagulation used for thromboembolic prophylaxis following total knee arthroplasty (TKA) could interfere with movement. This study compares the effect of 2 anticoagulants, enoxaparin and aspirin, on restoration of range of motion (ROM) after TKA. Two groups of 75 consecutive patients, matched for age, arthritic severity, and preoperative ROM, underwent TKA. Flexion and extension milestone measures were recorded daily. Results show a highly statistically significant difference (P<.001) between the 2 groups when comparing the days on which these milestones were achieved. Group 1 (enoxaparin) reached 90 degrees, 100 degrees and 110 degrees of flexion in 8.4, 10.4, and 12.4 days, respectively. Group 2 (aspirin) reached the same goals in 6.8, 8.5, and 10.6 days, respectively. At 15 months after surgery, no statistically significant difference in flexion was seen between the groups (122 degrees vs 121 degrees ). Enoxaparin delayed the return of early but not long-term flexion after TKA.