Early diagnosis of deep vein thrombosis in female patients who undergo total knee arthroplasty with measurement of P-selectin activation

Efficacy of pulse oximetry for early diagnosis of pulmonary embolism after total knee arthroplasty

INTRODUCTION

Early diagnosis and aggressive treatment of pulmonary embolism (PE) are crucial for preventing severe complications after total knee arthroplasty (TKA). This study aimed to examine the efficacy of measuring oxygen saturation (SpO2) using a pulse oximeter for early diagnosis of PE after total knee arthroplasty (TKA).

MATERIALS AND METHODS

We consecutively examined 1645 patients who underwent TKA between January 2015 and November 2019. Postoperative SpO2 was measured with a pulse oximeter, which was stopped if SpO2 was maintained at ≥ 95% until postoperative day 2 (POD2). To diagnose PE, computed tomographic pulmonary angiography (CTPA) was performed for specific indications, including persistently low SpO2 < 95% (group 1), sudden decrease in SpO2 (group 2), and decrease in SpO2 after POD3 with presenting symptoms (group 3). Also, we divided the patients into unilateral, simultaneous and sequential TKA groups and compared the results with specific statistical techniques.

RESULTS

Of the 1645 patients who underwent TKA, there were 20 patients with PE (1.2%), and symptomatic PE was observed in only 4 patients (0.24%). CTPA was performed in 58 (3.5%) patients, of whom 20 were diagnosed with PE. In groups 1 (n = 34), 2 (n = 21), and 3 (n = 3), CTPA was performed 2.4, 2.6, and 8.3 days after TKA, respectively, and 12, 8, and 0 patients were diagnosed with PE, respectively. Of the 782, 416, and 447 unilateral, simultaneous, and sequential (done in same admission with interval 1 or 2 weeks) patients with TKA, 38, 18, and 2 received CTPA, and 13, 6, and 1 were diagnosed with PE, respectively. All patients diagnosed with PE have persistently low SpO2 < 95% (group 1), or sudden decrease in SpO2 (group 2) until POD2. Of the patients diagnosed with PE, SpO2 decreased without the presentation of symptoms in 16 patients (11 and 5 from groups 1 and 2, respectively) and with the presentation of symptoms, such as mild dyspnea and chest discomfort, in 4 patients (1 and 3 from groups 1 and 2, respectively).

CONCLUSIONS

Measuring SpO2 using a pulse oximeter until POD2 was an effective method for early diagnosis of PE after TKA. No case of morbidity or mortality was observed after early diagnosis with early stage CTPA and management of PE. We recommend measuring SpO2 with a pulse oximeter for early diagnosing of PE in TKA.

Cytokines, Adhesion Molecules, and Matrix Metalloproteases as Predisposing, Diagnostic, and Prognostic Factors in Venous Thrombosis

The inflammatory response is a well-established part of, and a prerequisite for, venous thrombosis. To better understand the pathophysiology of venous thrombosis and to identify improved diagnostic biomarkers, further studies of the relationship between inflammation and coagulation are needed. We review previous studies concerning inflammatory biomarkers in venous thromboembolism, in particular cytokines, soluble adhesion molecules and matrix metalloproteases as predisposing, diagnostic and prognostic factors in venous thrombosis. Elevated cytokines and genetic alterations coding for cytokines are found in several patient cohorts which indicate that cytokines are involved as predisposing factors in venous thrombosis development. Increased levels of pro-inflammatory cytokines are detected both in animal models and in patients with acute venous thrombosis and clinical trials, although currently without evident diagnostic value. Adhesion molecules are crucial in the development of venous thrombosis, especially P-selectin seems important in initiating leukocyte accumulation and adhesion to endothelium for subsequent platelet accumulation. Several studies have demonstrated increased soluble P-selectin levels in patients with venous thrombosis, emphasizing its potential role as diagnostic marker and also as a therapeutic target. Matrix metalloproteases are essential effectors during venous thrombosis resolution and may impact vessel wall fibrosis, and together with their natural occurring inhibitors are crucial in acute and chronic thrombosis pathophysiology. Furthermore, studies in animal models of venous thrombosis have demonstrated anti-inflammatory treatment to be effective in terms of thrombus resolution and reduction of vessel wall damage, without increase in bleeding risk during the course of treatment. Thus, soluble mediators should be further investigated both as possible biomarkers and therapeutic targets in venous thromboembolic disease.

Prediction of Venous Thromboembolism after Total Knee Arthroplasty Using Dielectric Blood Coagulometry

BACKGROUND

Venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) frequently occurs in patients undergoing total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of dielectric blood coagulometry (DBCM) as a new technique for predicting postoperative VTE.

METHODS

Thirty patients undergoing TKA were enrolled. DVT was diagnosed by ultrasonography preoperatively and on the fourth or fifth postoperative day. Enhanced computed tomography was performed to detect PE on the fourth postoperative day. The day after surgery, a blood sample was measured by DBCM. All patients received fondaparinux or low-molecular-weight heparin for postoperative thromboprophylaxis.

RESULTS

Eighteen of the 30 patients had DVT postoperatively, and 10 had asymptomatic PE. Seven patients had both DVT and PE. The patterns of permittivity as a function of time and frequency from the DBCM measurement were different between patients with and without VTE. The sensitivity and specificity of the parameter constructed from a set of permittivities at the frequencies of 2.5 kHz, 1 MHz, and 10 MHz were 90% and 78%, respectively.

CONCLUSIONS

DBCM was effective and efficient for predicting VTE after TKA.

The incidence of pulmonary embolism and deep vein thrombosis after knee arthroplasty in Asians remains low: a meta-analysis

BACKGROUND

While Western literature has mostly reported the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) after TKA with chemoprophylaxis, the Asian literature still has mostly reported the incidence without chemoprophylaxis. This may reflect a low incidence of DVT and PE in Asian patients, although some recent studies suggest the incidence after TKA in Asian patients is increasing. Moreover, it is unclear whether the incidence of DVT and PE after TKA is similarly low among different Asian countries.

QUESTIONS/PURPOSES

We therefore determined the overall incidence of symptomatic PE and DVT without chemoprophylaxis after TKA in the Asian population, determined whether the incidence had a tendency to increase over time in Asia, and compared the incidence of symptomatic PE and DVT among Asian countries through a meta-analysis.

METHODS

We searched the PubMed, Embase, Cochrane Library, Web of Science, and Google Scholar websites for prospective studies published between 1996 and 2011. A total of 1947 patients from 18 studies were reviewed for meta-analysis.

RESULTS

The incidence of symptomatic PE was 0.01%. The incidences of overall DVT, proximal DVT, and symptomatic DVT were 40.4%, 5.8% and 1.9%, respectively. We found no difference in incidence of symptomatic PE among Asian countries and no trends in changes of the incidence over time.

CONCLUSIONS

The incidence of symptomatic PE and DVT after TKA without prophylaxis is low in Asian countries and has not changed over time, despite Westernizing lifestyles and an aging populace. Further investigation with large randomized studies is necessary to confirm our findings and identify risk factors predisposing to DVT.

Evaluation of soluble P-selectin as a marker for the diagnosis of deep venous thrombosis

OBJECTIVE

The combination of D-dimer and Wells score can exclude, but not confirm, the diagnosis of deep venous thrombosis (DVT). Since thrombosis and inflammation are interrelated, we evaluated the combination of soluble P-selectin (sPsel) with other inflammatory biomarkers for the diagnosis of DVT.

METHODS

Sixty-two positive and one hundred and sixteen patients with negative DVT, by duplex scan, were prospectively evaluated for sPsel, D-dimer, C-reactive protein (CRP), microparticles (MPs; total, leukocyte, and platelet-derived and tissue factor positive microparticles), and clinical Wells score.

RESULTS

Biomarkers and clinical scores that differentiated DVT positives from negatives were sPsel (87.3 vs 53.4 ng/mL, P < .0001), D-dimer (5.8 vs 2.1 mg/ L, P < .0001), CRP (2.1 vs 0.8 μg/mL, P < .0005), and Wells score (3.2 vs 2.0, P < .0001). For MP analysis, platelet-derived MPs were found to differentiate DVT from negatives. Using multivariable logistic regression, a combination of sPsel and Wells score could establish the diagnosis of DVT (cut point ≥ 90 ng/mL + Wells ≥ 2), with a specificity of 96% and positive predictive value (PPV) of 100%, and could exclude DVT diagnosis (cut point ≤ 60 ng/mL and Wells <2) with a sensitivity of 99%, a specificity of 33%, and a negative predictive value (NPV) of 96%.

CONCLUSION

This study establishes a biomarker and clinical profile combination that can both confirm and exclude the diagnosis of DVT.

Platelet and leukocyte activation in salvaged blood and the effect of its reinfusion on the circulating blood

Postoperative wound drainage reinfusion reduces the frequency of homologous blood transfusion. The salvaged blood is depleted of coagulation factors but may contain platelets and leukocytes which are activated, and therefore potentially procoagulant. We ascertained the degree of activation of platelets and leukocytes in salvaged blood and asked whether their infusion produced any measurable effect on patients' coagulation system. We prospectively randomized 24 patients who had total knee arthroplasties to reinfusion of salvaged autologous blood (n = 12) or a standard drain with no reinfusion (n = 12). Analysis of the salvaged blood showed marked activation of platelets as shown by their expression of P-selectin, CD40 ligand, and Factor V/Va, and as increased numbers of platelet-derived microparticles. After reinfusion there was no measurable effect on activation markers of circulating platelets or leukocytes but there was a decrease in platelet count in the reinfused group compared with the control group. Levels of prothrombin fragment F1 + 2 (suggesting thrombin formation) increased in the reinfused group compared with control group, possibly indicating activation of coagulation systemically. The platelets and leukocytes in salvaged blood are markedly activated and their reinfusion causes a decrease in platelet count in the recipient and a possible increase in thrombin generation potentially favoring thrombosis.

[Platelet activation and hypercholesterolemia in the pathogenesis of deep vein thrombosis]

Currently it is accepted that deep vein thrombosis is a multifactorial event in which the presence of activated platelets and also plasmatic lipids seems to play a pivotal role that it is not well established in the scientific bibliography. Due to the non consensus state about these topics between the different groups working in these aspects, the topic involving deep vein thrombosis-platelets-lipids, and also their interactions, still is an interesting area of investigation, in which it is necessary to carry out studies with the aim of establishing risk factors, initial diagnostic methods and clinical assays to probe the efficacy of new therapies.

The role of inflammation in early and late venous thrombosis: Are there clinical implications?

Venous thrombosis is associated with a significant inflammatory response. Inflammatory cells, adhesion molecules (especially selectins), cytokines, and procoagulant microparticles appear to be associated with the thrombogenic process. Once thrombus forms, inflammatory cells are important to thrombus resolution along with fibrinolytic agents and proinflammatory mediators. Collagen and elastin breakdown by the DVT renders the vein wall stiff and non-compliant. Rapid and complete thrombus resolution should lessen vein wall damage and lessen or prevent the development of chronic venous insufficiency. Understanding the basic biology of thrombogenesis and thrombus resolution is important, as novel therapies to both prevent and treat venous thrombosis and hasten thrombus resolution should result from a better understanding of the basic biological mechanisms.

Aprotinin and epsilon aminocaproic acid are effective in reducing blood loss after primary total hip arthroplasty--a prospective randomized double-blind placebo-controlled study

A prospective randomized double-blind placebo-controlled study was undertaken to determine the efficacy and mechanism of action of two antifibrinolytic drugs aprotinin and epsilon aminocaproic acid (EACA) in reducing blood loss in primary unilateral total hip arthroplasty (THA). Aprotinin was administered as a bolus of 2 x 10(6) kallikrein inhibitor units (KIU) followed by 0.5 x 10(6) KIU h(-1) for 3 h, EACA was given as 10 g over 30 min followed by 5 g over 3 h. The median postoperative blood loss 24 h postoperatively was reduced from 450 mL in the placebo group to 180 mL for aprotinin (60% reduction, P < 0.001) and to 210 mL for EACA (53% reduction, P < 0.01). In this population, there was no reduction in the perioperative transfusion requirements. The mechanism of both drugs was independent of platelets as indicated by flow cytometric measurement of change of their expression of P-selectin, platelet-monocyte aggregates, V/Va and CD40 ligand. There were no thrombotic or infective complications and no adverse events were attributable to use of either drug. Infusion of either aprotinin or EACA at the doses described is a safe and effective means of reducing blood loss after THA. These therapies provide a means of reducing blood loss in THA patients.