Reactive thrombocytosis and risk of subsequent venous thromboembolism: a cohort study

Role of platelet count in a murine stasis model of deep vein thrombosis

Platelets are core components of thrombi but their effect on thrombus burden during deep vein thrombosis (DVT) has not been fully characterized. We examined the role of thrombopoietin-altered platelet count on thrombus burden in a murine stasis model of DVT. To modulate platelet count compared to baseline, CD1 mice were pretreated with thrombopoietin antisense oligonucleotide (THPO-ASO, 56% decrease), thrombopoietin mimetic (TPO-mimetic, 36% increase), or saline (within 1%). Thrombi and vein walls were examined on postoperative days (POD) 3 and 7. Thrombus weights on POD 3 were not different between treatment groups (p = .84). The mean thrombus weights on POD 7 were significantly increased in the TPO-mimetic cohort compared to the THPO-ASO (p = .005) and the saline (p = .012) cohorts. Histological grading at POD 3 revealed a significantly increased smooth muscle cell presence in the thrombi and CD31 positive channeling in the vein wall of the TPO-mimetic cohort compared to the saline and THPO-ASO cohorts (p < .05). No differences were observed in histology on POD 7. Thrombopoietin-induced increased platelet count increased thrombus weight on POD 7 indicating platelet count may regulate thrombus burden during early resolution of venous thrombi in this murine stasis model of DVT.

Risk assessment models for PICC-related venous thrombosis in adult patients with cancer: A network meta-analysis

OBJECTIVES

This review aims to compare the performance of available risk assessment models (RAMs) for predicting peripherally inserted central catheter-related venous thrombosis (PICC-RVT) in adult patients with cancer.

METHODS

A systematic search was conducted across ten databases from inception to October 20, 2023. Studies were eligible if they compared the accuracy of a RAM to that of another RAM for predicting the risk of PICC-RVT in adult patients with cancer. Two reviewers independently performed the study selection, data extraction and risk of bias assessments. A Bayesian network meta-analysis (NMA) was used to evaluate the performance of the RAMs.

RESULTS

A total of 1931 studies were screened, and 7 studies with 10 RAMs were included in the review. The most widely used RAMs were the Caprini (4 studies), Padua prediction score (3 studies), Autar (3 studies), Michigan risk score (2 studies) and Seeley score (2 studies). The sensitivity, specificity and accuracy varied markedly between the models. Notably, the Caprini score achieved higher sensitivity than 4 RAMs (Wells, Revised Geneva, modified MRS, MRS). The Michigan risk score had greater specificity than did the other 6 RAMs (Caprini, Autar, Padua, Seeley, the novel RAM, Wells). The predictive accuracy of the MRS is significantly greater than that of the Caprini and Autar RAM.

CONCLUSION

The MRS could be the most accurate RAM for identifying patients at high risk of PICC-RVT. However, as limited studies are available, more rigorous studies should be conducted to examine the accuracy of the Michigan risk score for PICC-RVT in different contexts.

Outcomes of Patients with Preoperative Thrombocytosis After Hip Fracture Surgery

INTRODUCTION

Low platelet counts have clinically relevant effects on patient outcomes after hip fracture surgery; however, the relationship between abnormally high platelet counts and postoperative outcomes in this population is unknown.

METHODS

The ACS-NSQIP database was queried for patients who underwent hip fracture surgery between 2015 and 2019. Outcomes were compared between patients with normal platelet counts (150,000 to 450,000/μL) and thrombocytosis (>450,000/μL).

RESULTS

Eighty-six thousand three hundred eleven hip fracture patients were identified, of which 1067 (1.2%) had preoperative thrombocytosis. Compared with patients with normal platelet counts, patients with preoperative thrombocytosis had increased rates of 30-day mortality (6.4% vs 4.5%, P = 0.004; OR 1.15 [95% CI 0.88 to 1.50], P = 0.322) as well as increased rates and odds of readmission (11.4% vs 7.8%, P < 0.001; OR 1.35 [95% CI 1.10 to 1.65], P = 0.004) and venous thromboembolic events (3.2% vs 1.7%, P < 0.001; OR 1.88 [95% CI 1.31 to 2.71], P < 0.001).

CONCLUSIONS

Hip fracture patients with preoperative thrombocytosis had increased rates of early mortality as well as increased odds of venous thromboembolic events and readmission. A patient with thrombocytosis may benefit from close postoperative surveillance and careful follow-up. Future prospective studies are needed to verify causation and investigate how to mitigate adverse outcomes in hip fracture patients with preoperative thrombocytosis.

Reevaluating Thrombocytosis as a Risk Factor in Free Flap Surgery: Does Timing Matter?

INTRODUCTION

Thrombocytosis, defined as a platelet count >400,000, has been implicated as a risk factor in free flap failure. Despite proposed mechanisms of pedicle thrombosis, recent studies have suggested that thrombocytosis has no effect on free tissue transfer viability. Risk factors that may compromise successful free tissue transfer should be understood and elucidated, with particular attention to thrombocytosis and its conflicting evidence in the literature. We hypothesize that thrombocytosis has no bearing on free flap success or the rates of pedicle thrombosis.

METHODS

Our institution performed a retrospective chart review on all patients who underwent free flap reconstruction over the past 6 years. Patient demographics, medical history, type and location of free tissue transfer, preoperative platelets, postoperative platelets, and flap outcomes and complications (wound dehiscence, infection, hematoma, seroma, and need for blood transfusion) were recorded. Independent t test, Mann-Whitney U tests, χ2 test, and Fisher exact tests were used to determine P values to compare flap outcomes in patients with thrombocytosis (platelet count >400,000) and those with platelet counts less than 400,000.

RESULTS

In our 502-patient cohort, 71 were found to have a platelet count >400,000 (35 preoperatively and 36 postoperatively) and 431 patients had platelet counts <400,000. There were 42 reconstructive failures (flap success rate of 91.6%) and 111 returns to the operating room (OR). For patients with postoperative thrombocytosis, 24 flaps returned to the OR (44.4%), whereas in patients without thrombocytosis, 87 flaps returned to the OR (19.4%; P < 0.001). In patients with postoperative thrombocytosis, 10 OR returns were due to pedicle venous thrombosis (18.5%), in comparison to 10 returns for venous thrombosis in those with normal platelets (2.2%; P < 0.001). There was a small difference in free flap success rates between those with postoperative thrombocytosis and normal platelets, 88.7% versus 92.11%; however, this was not statistically significant ( P = 0.71). The thrombocytosis group had a higher incidence of overall postoperative complications ( P = 0.002).

CONCLUSIONS

Thrombocytosis has historically been cited as a risk factor for free flap reconstruction failure with recent conflicting evidence in the literature. In patients with postoperative thrombocytosis, we found an increased risk of venous thrombosis; however, this did not result in increased flap failure. There was an increase in postoperative complications, which corresponds with National Surgical Quality Improvement Program data reported in the literature. We suspect that thrombocytosis is not a harbinger of free flap failure but rather a marker for overall inflammation, which may confer a higher rate of venous thrombosis requiring reoperation and postoperative complications.

Coagulation profiles in patients with sepsis/septic shock identify mixed hypo-hypercoagulation patterns based on rotational thromboelastometry: A prospective observational study

INTRODUCTION

Sepsis-induced hemostatic disturbances are common and are associated with poor outcomes. Additionally, conventional coagulation tests (CCTs) overdiagnose hypocoagulation and cannot detect hypercoagulation and hyperfibrinolysis. The aim of this study was to describe the coagulation profiles of patients with sepsis/septic shock using rotational thromboelastometry (ROTEM) and to compare coagulation states between sepsis and septic shock groups and between surviving and non-surviving groups.

MATERIALS AND METHODS

This prospective, observational, single-center study was conducted in the intensive care unit (ICU) of the University Medical Center Ho Chi Minh City, from 6/2020-12/2021. Patients aged ≥18 years with sepsis or septic shock according to the Sepsis-3 criteria were included. ROTEM and CCTs were concurrently performed within the first 24 h of ICU admission.

RESULTS

In total, 161 patients were enrolled. Based on ROTEM, 72.7 % of patients with sepsis/septic shock had coagulation disorders, including 25.5 % hypercoagulation, 54.7 % hypocoagulation, 13.6 % mixed hypo-hypercoagulation patterns, and 18.6 % hyperfibrinolysis. A common mixed disorder subtype was characterized by prolonged initial clotting time (CT) with subsequently increased clot firmness. Fibrinogen levels and maximum clot formation (MCF)-fibtem were strongly correlated (rho = 0.73, p < 0.05). Hypocoagulation was observed more in the septic shock group than in the sepsis group. Compared to survivors, non-survivors had more prolonged CT-extem.

CONCLUSIONS

ROTEM could identify hypocoagulability, hypercoagulability, mixed hypo-hypercoagulability patterns, and hyperfibrinolysis in patients with sepsis/septic shock. Elevated MCF-fibtem and elevated fibrinogen levels were notably common and strongly correlated. The septic shock group had more hypocoagulation than the sepsis group. Lastly, non-survivors had more prolonged CT-extem than survivors.

Role of reactive thrombocytosis after primary cytoreductive surgery in advanced ovarian cancer

We investigated the incidence of reactive thrombocytosis after maximal cytoreductive surgery in advanced epithelial ovarian cancer (EOC) and its role in patient survival. We retrospectively reviewed the electronic medical records of patients who underwent primary cytoreductive surgery for advanced EOC from 1 January 2012 to 31 December 2017. We analyzed the serum platelet counts at various time points from before surgery, during the peri-operative period, and after each cycle of adjuvant chemotherapy. A total of 474 patients were eligible for the analysis. Among them, 401 patients (84.6%) had FIGO stage III disease status. The most common histology type was serous adenocarcinoma (405 patients, 85.4%). Seventy-nine patients (22.6%) received splenectomy, and optimal cytoreduction was achieved in 326 patients (68.8%). A week after surgery, thrombocytosis was observed in 165 patients (34.8%) in the entire cohort. Higher platelet counts were observed in patients with splenectomy compared with patients without splenectomy. In particular, thrombocytosis on the fifth cycle of adjuvant chemotherapy showed the most significant effects on overall survival in multivariate analysis. In a logistic regression model, splenectomy was significantly attributed to thrombocytosis on the fifth cycle of chemotherapy. Reactive thrombocytosis after primary cytoreductive surgery is associated with poor survival in advanced EOC, particularly when thrombocytosis is observed during adjuvant chemotherapy.

Abnormal Preoperative Platelet Count May Predict Postoperative Complications Following Shoulder Arthroplasty

Background

The purpose of this study is to investigate the association between preoperative platelet counts and postoperative complication rates within 30 days of total shoulder arthroplasty (TSA).

Methods

The American College of Surgeons National Surgical Quality Improvement database was queried for all patients who underwent TSA between 2015 and 2019. The study population was then divided into 5 groups based on their preoperative platelet count: <100k (moderate-to-severe thrombocytopenia), 100-150k (mild thrombocytopenia), 150-200k (low-normal preoperative platelet count), 200-450k (normal, reference cohort), and >450k (thrombocytosis). Postoperative complications within 30 days of the TSA were collected. Multivariate logistic regression analysis was conducted to investigate the relationship between preoperative platelet counts and postoperative complications.

Results

A total of 19,721 patients undergoing TSA between 2015 and 2019 were included in this study. One hundred fifty-five patients (0.8%) had moderate-to-severe thrombocytopenia, 982 (5.0%) had mild thrombocytopenia, 3945 (20.0%) had a low-normal preoperative platelet count, 14,386 (72.9%) had a normal preoperative platelet count, and 253 (1.3%) had thrombocytosis. An increasing rate of overall complications was observed as the severity of thrombocytopenia progressed from low-normal (6.4%) to mild thrombocytopenia (10.2%) and to moderate-to-severe thrombocytopenia (18.7%). The overall complication rate of the thrombocytosis cohort was 14.6%. In comparison to normal platelet count, low-normal thrombocytopenia, mild thrombocytopenia, moderate-to-severe thrombocytopenia, and thrombocytosis were identified by multivariate analysis as significant predictors of overall complications (odds ratios [ORs] of 1.12, 2.15, 2.43, 2.71, respectively), postoperative anemia requiring transfusion (ORs of 1.63, 3.45, 5.97, 4.21, respectively), and minor complications (ORs of 1.39, 2.64, 3.40, 3.34, respectively). Minor complications include progressive renal insufficiency, urinary tract infection, transfusions within 72 hours after surgery, pneumonia, and superficial incisional surgical site infection.

Conclusion

Increasing severity of thrombocytopenia correlated with higher overall postoperative complication rates following TSA. Interestingly, patients with thrombocytosis had the highest overall postoperative complication rates among all cohorts included in this study. Platelet counts are often the reflection of other comorbidities and a good indicator of patient's general health status. Long-term optimization of abnormal platelet counts may potentially reduce surgical complications.

Reactive Thrombocytosis Leading to Recurrent Arterial Thrombosis Reversed by Management of a Prosthetic Joint Infection of the Hip

Prosthetic joint infections (PJIs) still pose a severe challenge for patients and the overall health care system. Infection, and PJI in particular, is a known cause of reactive thrombocytosis. Thromboembolic complications secondary to reactive thrombocytosis are infrequent and arterial thromboses are rarely described. We present the case of a 64-year-old female with reactive thrombosis and recurrent arterial thrombosis due to bilateral streptococcal PJI of the hip. Multiple episodes of acute ischemia of the right lower limb ultimately led to transfemoral amputation. Only after bilateral irrigation and debridement for infection control did the thrombocytosis resolve without any further thromboembolic complications. Early recognition of thrombocytosis, use of anti-platelet agents and early surgical treatment of the underlying infection (even when a conservative treatment may otherwise be considered) could have avoided this potentially life-threatening complication.

Predictable Risk Factors of Upper-Extremity Deep Venous Thrombosis in a Level I Trauma Center

Background

Venous thromboembolism is a common cause of morbidity and mortality in hospital patients, especially that of the lower extremities. Risk factors and diagnostic elements of upper-extremity deep-vein thrombosis (UEDVT) are poorly understood compared to those of the lower extremities. The primary objectives of this study were to identify predictive risk factors of secondary UEDVT.

Methods

This retrospective study included all nonpregnant patients aged >18 years who had undergone upper-extremity duplex scans to check for the presence of secondary UEDVT at Richmond University Medical Center from January 2014 to March 2020. Patients were stratified by presence or absence of UEDVT. Collected data points included patient demographics, comorbidities, central-line use, platelet count at time of scan, length of stay, and overall mortality. IBM 27.0 was used for all statistical analysis, with p<0.05 considered significant.

Results

A total of 1,009 upper extremity venous duplex studies were included. There were no significant differences in age, sex, race, or mean platelet levels between patients diagnosed with DVT and those without (p<0.05). After multinomial regression analysis, central venous catheter (CVC; 26.8% versus 78.5%, aOR 1.770, 95% CI 1.150–2.725; p<0.002), peripherally inserted central catheter (PICC) line (17.5% versus 82.5%, aOR3.254, 95% CI 1.997–5.304; p<0.001), hypertension (67.8% versus 28.8%, aOR 1.641, 95% CI 1.136–2.369; p<0.001), chronic kidney disease (CKD; 34.5% versus 65.5%, aOR 1.743, 95% CI 1.201–2.531; p<0.001), and malignancy (27.1% versus 74.6%, aOR 1.475, 95% CI 0.994–2.190; p<0.053) were found to be independent predictors of UEDVT.

Conclusion

Use of CVC or PICC line, preexisting diagnosis of hypertension, malignancy, and CKD were independent risk factors of UEDVT, while there was no significant correlation between increased platelet levels and UEDVT.

Alterations of coagulation and fibrinolysis in patients with blunt splenic injury after splenic artery embolization

Background

Thrombotic complications following splenectomy have been documented. However, there has been sparse literature regarding thrombotic complications following splenic artery embolization (SAE).The objective of this study was to determine changes in coagulation and fibrinolysis and assess the thrombotic risk after SAE in patients with blunt splenic injury (BSI).

Methods

This study included 38 BSI patients who were hemodynamically stable on admission. SAE was performed if the splenic injury was classed as grade III or greater and had no requirement of immediate surgery. Platelet (PLT), fibrinogen (FIB), D‐dimers (D‐D), fibrinogen/fibrin degradation products (FDP), antithrombin III (AT III), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), hemoglobin (Hb), and hematocrit (Hct) were measured before SAE procedures and then 1d, 3d, and 7d after SAE.

Results

The technical success rate of SAE and the splenic salvage rate were 100%. There was no mortality. Compared with pre‐SAE values, the levels of PLT, FIB, D‐D, and FDP increased significantly at 3 days and 7 days after SAE (p < 0.05). However, AT III, PT, APTT, TT, Hb, and Hct showed no statistically significant difference at 1d, 3d, and 7d after SAE (p > 0.05).

Conclusion

Alterations in PLT and hemostatic parameters might contribute to the increased risk of thrombotic complications in BSI patients undergoing SAE. Thromboembolism following SAE should be considered and thrombotic prophylaxis should be recommended.

Incidence and Risk Factors for Venous Thromboembolism Following 2462 Major Abdomino-Pelvic Surgeries in Tertiary Hospital

Purpose

To determine the incidence and risk factor of postoperative venous thromboembolism (VTE) in Thai populations and to evaluate morbidity, mortality, bleeding complications and the benefit of thromboprophylaxis in real-world practice.

Patients and Methods

We performed a retrospective, single-center, cohort study of patients from all age groups who underwent elective open or laparoscopic major abdomino-pelvic surgery between January 2008 and December 2018 at Chulabhorn Hospital, Bangkok, Thailand. We collected general medical information and specific data based on items from the Caprini risk scoring system.

Results

A total of 2462 major abdomino-pelvic surgeries were included. The study population consisted of 742 males (30.1%) and 1720 females (69.9%) aged 54.59 ± 13.27 years. The incidence of VTE in Thai patients that underwent major abdominal surgery was 0.48%. The most frequent influencing factor for VTE was a history of pulmonary embolism, which increased the risk of VTE 98.28-fold, whereas a history of deep vein thrombosis increased the risk of VTE by 12.34-fold. Other factors influencing VTE development were obesity, anticoagulant use, postoperative chemotherapy, preoperative chemotherapy, endometrium cancer, tumor-node-metastasis (TNM) stage 4 and American College of Chest Physicians (ACCP) class 4. Protective factors included no history of VTE, laparoscopic surgery, TNM stage 0 and benign disease and BMI<30. VTE significantly increased mortality whereas following ACCP guideline reduced mortality.

Conclusion

Post-operative VTE incidence in Thai patients undergoing major abdomino-pelvic surgery was lower compared with Western patients. Factors influencing for VTE were history of VTE, anticoagulant use, postoperative chemotherapy, preoperative chemotherapy, endometrium cancer, TNM stage 4 and ACCP class 4. Following ACCP guideline reduced the incidence of mortality.

Stroke in SARS-CoV-2 Infection: A Pictorial Overview of the Pathoetiology

Since the early days of the pandemic, there have been several reports of cerebrovascular complications during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Numerous studies proposed a role for SARS-CoV-2 in igniting stroke. In this review, we focused on the pathoetiology of stroke among the infected patients. We pictured the results of the SARS-CoV-2 invasion to the central nervous system (CNS) via neuronal and hematogenous routes, in addition to viral infection in peripheral tissues with extensive crosstalk with the CNS. SARS-CoV-2 infection results in pro-inflammatory cytokine and chemokine release and activation of the immune system, COVID-19-associated coagulopathy, endotheliitis and vasculitis, hypoxia, imbalance in the renin-angiotensin system, and cardiovascular complications that all may lead to the incidence of stroke. Critically ill patients, those with pre-existing comorbidities and patients taking certain medications, such as drugs with elevated risk for arrhythmia or thrombophilia, are more susceptible to a stroke after SARS-CoV-2 infection. By providing a pictorial narrative review, we illustrated these associations in detail to broaden the scope of our understanding of stroke in SARS-CoV-2-infected patients. We also discussed the role of antiplatelets and anticoagulants for stroke prevention and the need for a personalized approach among patients with SARS-CoV-2 infection.

Cerebral venous thrombosis, neutropenia and iron-deficiency anemia in Huntington disease

Neurologic and nonneurologic manifestations have been shown for Huntington disease (HD) as a genetic neurodegenerative disorder. However, cerebral venous thrombosis (CVT), iron-deficiency anemia and neutropenia have not been reported as its presentations to date. We introduce the first case of a HD patient with CVT, iron-deficiency anemia and neutropenia. All transient and chronic risk factors for development of these manifestations were ruled out. According to the experimental evidences reviewed in this article, we suggest that HD itself could promote formation of CVT, iron-deficiency anemia and neutropenia through vascular and blood cell abnormalities.

Characterization of the rate, predictors, and thrombotic complications of thrombocytosis in iron deficiency anemia

The association of thrombocytosis with iron deficiency anemia (IDA) is well-recognized, but data describing the rate, predictors, and risk of thrombotic complications associated with IDA-related thrombocytosis are limited. We queried an institutional patient data repository containing comprehensive chart data for over 6 million patients to identify IDA patients with and without thrombocytosis and thrombotic events over a 40-year time period (1979 to 2019). Demographics, hematological parameters, thrombosis history, and other medical history were collected. Fidelity of query data was assessed via detailed manual chart review of 700 patients, including confirmation of ferritin and hematologic parameters in addition to temporal and clinical association of thrombocytosis. Our queries identified 36 327 cases of IDA of which 15 022 had thrombocytosis. Following assessment for data integrity, we observed a thrombocytosis rate of 32.6% in patients with IDA. The rate of thrombosis was calculated to be 7.8% in patients with IDA and 15.8% in patients with IDA and thrombocytosis. Platelet mass index at time of peak thrombocytosis was significantly higher than at baseline and was strongly negatively correlated with hemoglobin at peak thrombocytosis. A multivariable model demonstrated a significant predictive relationship between decreasing hemoglobin and increasing platelet count at peak thrombocytosis. In conclusion, we observed reactive thrombocytosis in one-third of IDA patients, and a 2-fold thrombosis risk in patients with IDA and thrombocytosis compared with patients with IDA alone. Given the global burden of untreated and undertreated IDA, adequate IDA treatment may reduce thrombotic complications and associated morbidity and mortality.

Postoperative Pressure Ulcers After Geriatric Hip Fracture Surgery Are Predicted by Defined Preoperative Comorbidities and Postoperative Complications

INTRODUCTION

The current study sought to determine the factors predictive of postoperative pressure ulcer development by analyzing extensive multicenter outcomes data from the 2016 American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database.

METHODS

The 2016 NSQIP Participant Use File and Hip Fracture Procedure Targeted file were used to identify the risk factors for the development of postoperative pressure ulcers after hip fracture surgery in a geriatric cohort. Multivariate regressions were performed to identify preoperative comorbidities and postoperative complications that are risk factors for developing postoperative pressure ulcers.

RESULTS

Of 8,871 geriatric hip fracture patients included in the study cohort, 457 (5.15%) developed pressure ulcers. Multivariate regressions identified the following preoperative risk factors for developing a postoperative pressure ulcer (in order of decreasing relative risk): preoperative sepsis, elevated platelet count, insulin-dependent diabetes, and preexisting pressure ulcer. Multivariate regressions also identified the following postoperative complications as risk factors for developing a postoperative pressure ulcer: postoperative sepsis, postoperative pneumonia, urinary tract infection, and postoperative delirium.

DISCUSSION

The identified preoperative factors and postoperative complications should help guide quality improvement programs.

Platelets in Kawasaki disease: Is this only a numbers game or something beyond?

Kawasaki disease (KD) is a medium vessel vasculitis with predilection to cause coronary artery abnormalities. KD is now the most common cause of acquired heart disease in developed countries. Thrombocytosis is consistently found in patients with KD, usually in 2nd to 3rd week of illness. Thrombocytopenia has occasionally been reported in the acute phase of KD. An increase or decrease in platelet number in patients with KD was initially considered to be a benign phenomenon. However, recent literature on platelet biology in KD has suggested that platelets are not only increasing but are rather activated. This phenomenon has been found to increase the risk of thrombosis in these patients. Similarly a fall in platelet counts during acute stage of KD has also been found to be associated with increased severity of disease. In this review, we update on the current best understanding about pathogenic role of platelets in patients with KD.

Anaemia at admission is associated with poor clinical outcome in cerebral venous thrombosis

Background and purpose

Anaemia is associated with poor clinical outcome after ischaemic and haemorrhagic stroke. The association between anaemia and outcome in patients with cerebral venous thrombosis (CVT) was examined.

Methods

Consecutive adult patients with CVT were included from seven centres. Anaemia at admission was scored according to World Health Organization definitions. Poor clinical outcome was defined as a modified Rankin Scale score 3–6 at last follow‐up. A multiple imputation procedure was applied for handling missing data in the multivariable analysis. Using binary logistic regression analysis, adjustments were made for age, sex, cancer and centre of recruitment (model 1). In a secondary analysis, adjustments were additionally made for coma, intracerebral haemorrhage, non‐haemorrhagic lesion and deep venous system thrombosis (model 2). In a sensitivity analysis, patients with cancer were excluded.

Results

Data for 952 patients with CVT were included, 22% of whom had anaemia at admission. Patients with anaemia more often had a history of cancer (17% vs. 7%, P < 0.001) than patients without anaemia. Poor clinical outcome (21% vs. 11%, P < 0.001) and mortality (11% vs. 6%, P = 0.07) were more common amongst patients with anaemia. After adjustment, anaemia at admission increased the risk of poor outcome [adjusted odds ratio (aOR) 2.4, 95% confidence interval (CI) 1.5–3.7, model 1]. Model 2 revealed comparable results (aOR 1.9, 95% CI 1.2–3.2), as did the sensitivity analysis excluding patients with cancer (aOR 2.3, 95% CI 1.3–3.8, model 1).

Conclusion

The risk of poor clinical outcome is doubled in CVT patients presenting with anaemia at admission.

Clinical and laboratory assessment of a patient with thrombocytosis

Elevated platelet counts are frequently encountered in hospital medicine and arise from both physiological and pathological mechanisms. Thrombocytosis may be secondary, reflecting an inflammatory state, iron deficiency, recent surgery or point towards an underlying neoplasm. Thrombocytosis may be the presenting sign of solid tumours and haematological conditions. The discovery of the activating mutations affecting thrombopoiesis led to greater understanding of the pathobiology of essential thrombocythaemia and other myeloproliferative neoplasms. The investigation of suspected primary thrombocytosis has evolved to include testing for these disease-associated mutations. Therapy for patients with essential thrombocythaemia aims to reduce their risk of thrombotic complications by addressing cardiovascular risk factors, and using antiplatelet agents and, in selected patients, cytoreductive therapy. This article provides a logical approach to distinguishing reactive or secondary thrombocytosis from thrombocytosis associated with an underlying myeloproliferative neoplasm and gives an overview of the management of essential thrombocythaemia.

Response patterns of routinely measured inflammatory and coagulatory parameters in sepsis

Background

Sepsis is characterized by a pro-inflammatory and pro-coagulatory shift which can induce life-threatening complications. Close monitoring and risk stratification of sepsis patients is crucial for proper treatment and consequently patient outcome. Therefore, this study focuses on the response patterns of inflammatory and coagulatory parameters used in clinical routines to estimate the course of sepsis.

Methods

A total of 1,110 patients diagnosed with sepsis were retrospectively analyzed to identify response patterns for risk stratification of routine parameters measured at the peak level of C-reactive protein. Cluster analysis was used and the differences in the patient characteristics and 28-day survival were assessed. Cox proportional hazards regression model for survival stratified by the clusters was performed.

Results

The analyses revealed the parameters to have five distinct response patterns. These clusters reflect the etiology as well as the course of sepsis associated with different mortalities. Here, impairment of the liver plays a crucial role in the ability to appropriately respond to sepsis. Of the routinely measured parameters, C-reactive protein and antithrombin seem to be unspecific for stratification of septic patients. Adjusted for the individual clusters, survival was associated with an increase in fibrinogen (p = 0.0042), platelets (p = 0.0003) and PT (p = 0.001) as well as a decrease in leukocytes (p = 0.034).

Conclusions

This study reveals that patients have distinct response patterns of inflammatory and coagulatory parameters depending on disease etiology. These patterns are associated with different mortalities although the patients have similar levels of C-reactive protein. Independently of the type of response, good coagulatory capacity seems to be crucial for patient survival.

Early venous thromboembolism at the beginning of palliative chemotherapy is a poor prognostic factor in patients with metastatic pancreatic cancer: a retrospective study

Background

This study investigated the prognostic effects of venous thromboembolism (VTE)-related factors in patients with metastatic pancreatic cancer receiving palliative chemotherapy. Predictive factors for VTE were also investigated.

Methods

A total of 216 patients diagnosed with metastatic pancreatic cancer who received gemcitabine-based palliative chemotherapy at our institution were retrospectively evaluated.

Results

VTE occurred in 51 (23.6%) patients during treatment and did not affect survival. However, patients who were diagnosed with VTE at the beginning of chemotherapy showed poor prognosis compared with patients diagnosed with VTE during chemotherapy: all patients (hazard ratio [HR] 1.897, p = 0.008); patients diagnosed with VTE (HR = 3.768, p = 0.001). Low serum sodium (Na) (< 135 mmol/L) and high Khorana score (≥3) were strong predictive factors of early VTE (odds ratio [OR] 5.109; 95% confidence interval [95% CI] = 1.010–25.845; p = 0.049 for Khorana score, OR 10.304; 95% CI = 1.036–102.466; p = 0.047) for hyponatremia).

Conclusions

Our study demonstrated that occurrence and detection of VTE in the early period of chemotherapy was the most significant VTE-related prognostic factor in patients with metastatic pancreatic cancer receiving chemotherapy. Prediction using the Khorana score and serum Na levels would be helpful in early diagnosis of VTE.

High energy injury is a risk factor for preoperative venous thromboembolism in the patients with hip fractures: A prospective observational study

BACKGROUND

The purpose of this study was to identify the incidence of preoperative venous thromboembolism (VTE), and determine if high energy hip fracture affects preoperative VTE occurrence.

METHODS

Three-hundred nine patients (244 low and 61 high energy injuries) treated between March 2015 and March 2017 were included in this study. Indirect multidetector computed tomographic venography for the detection of preoperative VTE was performed at admission. The incidence of preoperative VTE was compared between high and low energy injury hip fractures. Logistic regression analysis was used to identify independent risk factors for preoperative VTE.

RESULTS

The overall incidence of preoperative VTE was 18.4% (56 of 305 patients). Preoperative VTE was identified in 17 (27.9%) and 39 (16.0%) patients in the high and low energy injury groups, respectively (p = 0.034). Multivariate logistic regression analysis showed that high energy injury, history of VTE, and myeloproliferative disease were significant predictive factors of preoperative VTE (OR = 2.451; 95% CI = 1.227-4.896, OR = 11.174; 95% CI = 3.500-35.673, OR = 6.936; 95% CI = 1.641-29.321, respectively) CONCLUSION: Because high energy hip fracture is significantly associated with preoperative VTE occurrence, preoperative evaluation and proper thromboprophylaxis should be performed for patients with a high-energy hip fracture.

Bilateral visual loss and cerebral infarction after spleen embolization in a trauma patient with idiopathic thrombocytopenic purpura: A case report

RATIONALE

Splenic artery embolization (SAE) is a common procedure in trauma patients with blunt splenic injuries. We report a case of acute ischemic stroke following orthopedic surgery in a patient with post-SAE reactive thrombocytosis.

PATIENT CONCERNS

A 37-year-old woman with idiopathic thrombocytopenic purpura (ITP) suffered from multiple trauma scheduled for open reduction and internal fixation for right tibial and left radius fracture five days after SAE. The patient did not have any thromboembolic complications, although the platelet counts increased from 43 × 10/L to 568 × 10/L within two days after SAE. Surgery was completed under general anesthesia with tracheal intubation without complications. The patient complained of visual loss followed by limb weakness on the fourth and eighth hour postoperatively.

DIAGNOSES

Magnetic resonance imaging (MRI) of head demonstrated ischemic change over bilateral basal ganglia, and occipital areas, suggesting the diagnosis of cortical blindness.

INTERVENTIONS

To suppress platelet count and avoid platelet hyper-aggregation, anti-platelet drug (i.e., oral aspirin 100 mg daily), hydration, and hydroxyurea (i.e., 20 mg/kg daily) were used for the treatment of reactive thrombocytosis.

OUTCOMES

Although right-sided hemiparesis persisted, the patient reported mild visual recovery. She was discharged four months after SAE with active rehabilitation.

LESSONS

Our report highlights an increased risk of acute arterial thromboembolic events in patients with reactive thrombocytosis, especially those undergoing surgery.

Assessment of procoagulant potential in patients with reactive thrombocytosis and its association with platelet count

OBJECTIVE

We aimed to determine hemostatic changes and characterize the procoagulant potential among patients with reactive thrombocytosis (RT).

METHODS

Sixty patients with RT (median platelet count 718 × 10⁹ /L) and 20 healthy persons were tested for complete blood count, C-reactive protein, von Willebrand factor (VWF), factor VIII and fibrinogen, and thrombin generation. Platelet studies, including light transmission aggregometry and Cone and Plate(let) Analyzer, were also conducted. Reticulated platelets and platelet P-selectin expression were measured using flow cytometry.

RESULTS

Compared to patients with mild thrombocytosis (platelet count 500-700 × 10⁹ /L; n = 27), those with moderate-to-severe thrombocytosis (platelet count >700 × 10⁹ /L; n = 33) had significantly higher fibrinogen, factor VIII, and VWF antigen and activity levels; higher endogenous thrombin potential, peak thrombin generation and velocity index levels, and shorter time-to-peak thrombin level. VWF antigen and activity, fibrinogen, and factor VIII were positively associated with platelet count, whereas VWF activity/antigen ratio was inversely correlated. In a multivariate analysis of RT and control participants, only platelet count predicted endogenous thrombin potential with a positive-linear correlation. No patients developed acquired von Willebrand syndrome.

CONCLUSIONS

As determined by thrombin generation, RT was associated with in vitro prothrombotic tendency, which correlated with platelet count. This may explain the increased thromboembolic risk previously reported in patients with RT.

Platelet count and outcome in patients with acute venous thromboembolism

The relationship between platelet count and outcome in patients with acute venous thromboembolism (VTE) has not been consistently explored. RIETE is an ongoing registry of consecutive patients with acute VTE. We categorised patients as having very low- (<80,000/μl), low- (80,000/μl to 150,000/μl), normal- (150,000/μl to 300,000/μl), high- (300,000/μl to 450,000/μl), or very high (>450,000/μl) platelet count at baseline, and compared their three-month outcome. As of October 2012, 43,078 patients had been enrolled in RIETE: 21,319 presenting with pulmonary embolism and 21,759 with deep-vein thrombosis. In all, 502 patients (1.2%) had very low-; 5,472 (13%) low-; 28,386 (66%) normal-; 7,157 (17%) high-; and 1,561 (3.6%) very high platelet count. During the three-month study period, the recurrence rate was: 2.8%, 2.2%, 1.8%, 2.1% and 2.2%, respectively; the rate of major bleeding: 5.8%, 2.6%, 1.7%, 2.3% and 4.6%, respectively; the rate of fatal bleeding: 2.0%, 0.9%, 0.3%, 0.5% and 1.2%, respectively; and the mortality rate: 29%, 11%, 6.5%, 8.8% and 14%, respectively. On multivariate analysis, patients with very low-, low-, high- or very high platelet count had an increased risk for major bleeding (odds ratio [OR]: 2.70, 95% confidence interval [CI]: 1.85–3.95; 1.43 [1.18–1.72]; 1.23 [1.03–1.47]; and 2.13 [1.65–2.75]) and fatal bleeding (OR: 3.70 [1.92–7.16], 2.10 [1.48–2.97], 1.29 [0.88–1.90] and 2.49 [1.49–4.15]) compared with those with normal count. In conclusion, we found a U-shaped relationship between platelet count and the three-month rate of major bleeding and fatal bleeding in patients with VTE.

Etiology and clinical relevance of elevated platelet count in ICU patients : A retrospective analysis

BACKGROUND

Thrombocytosis is a common phenomenon in critically ill patients. Although thrombocytosis is an independent risk factor for complications, it does not seem to influence mortality in intensive care (ICU) patients.

OBJECTIVES

Our investigation aimed to evaluate the etiological and clinical relevance of a platelet count greater than 450 × 10⁹/l in ICU patients.

MATERIALS AND METHODS

Patients admitted for a minimum of 4 days to an interdisciplinary ICU during a 45-month period were enrolled in this retrospective observational study. Thrombocytopenic patients (platelet count <150 × 10⁹/l in at least one measurement) were excluded. The study patients were divided into two groups: thrombocytosis group (thrombocytes >450 × 10⁹/l in at least one measurement) and control group (thrombocytes = 150 - 450 × 10⁹/l during ICU stay). Univariate and multiple regression analysis were used to determine the influence of severe co-morbidities on the development of thrombocytosis and the association of elevated platelet count with thrombotic embolism, length of stay (LOS) in ICU, and mortality.

RESULTS

A total of 307 patients were analyzed, of whom thrombocytosis was observed in 119 cases. Independent risk factors for the development of thrombocytosis included SIRS, mechanical ventilation, and acute bleeding. Increasing age reduced the risk of thrombocytosis. Thromboembolism occurred in 16 patients (13.4%) with an elevated platelet count and only in nine patients (4.7%) with physiological platelet values (OR: 3.1; 95% CI: 1.3-7.2; p = 0.009). Mean duration of LOS was significantly longer in patients with thrombocytosis (25.2 vs.11.7 days, p < 0.0001). Elevated platelet count showed a negative correlation with ICU mortality (OR: 0.32; 95%-CI: 0.12-0.83; p = 0.019).

CONCLUSION

In our retrospective analysis the occurrence of thrombocytosis in a cohort of interdisciplinary ICU patients was associated with a higher rate of complications and longer LOS in the ICU. Despite these findings, thrombocytosis seems to reduce mortality in critical ill patients.

Hypercoagulability after distal pancreatectomy: Just meaningless alterations?

BACKGROUND

Perioperative and short-term postoperative parameters are similar comparing spleen-preserving distal pancreatectomy (SPDP) and distal pancreatectomy with splenectomy (DPS). But there are no sound data evaluating the long term risk of postoperative thromboses and infectious complications after splenectomy. The present study evaluated whether the coagulation status differs in patients after SPDP and DPS, and whether that matters clinically.

METHODS

A total of 41 patients after DP (SPDP = 20; DPS = 21) were followed up, focusing on alterations of patient coagulation and immune status. To assess kinetics of the coagulation process, qualitative tests (multiple platelet function analyzer, rotational thrombelastography) were used in addition to global coagulation tests.

RESULTS

Coagulation tests revealed a significant enhanced tendency for blood-platelet aggregation and coagulation activation in patients after DPS compared to patients after SPDP. No septic or thromboembolic events were observed in any patient.

CONCLUSION

Hypercoagulability in splenectomized patients persists over years. Thus, a correlation of this finding with thromboembolic events and mortality years after splenectomy should to be performed in a large cohort.

Applying the Cell-Based Coagulation Model in the Management of Critical Bleeding

The cell-based coagulation model was proposed 15 years ago, yet has not been applied commonly in the management of critical bleeding. Nevertheless, this alternative model may better explain the physiological basis of current coagulation management during critical bleeding. In this article we describe the limitations of the traditional coagulation protein cascade and standard coagulation tests, and explain the potential advantages of applying the cell-based model in current coagulation management strategies. The cell-based coagulation model builds on the traditional coagulation model and explains many recent clinical observations and research findings related to critical bleeding unexplained by the traditional model, including the encouraging results of using empirical 1:1:1 fresh frozen plasma:platelets:red blood cells transfusion strategy, and the use of viscoelastic and platelet function tests in patients with critical bleeding. From a practical perspective, applying the cell-based coagulation model also explains why new direct oral anticoagulants are effective systemic anticoagulants even without affecting activated partial thromboplastin time or the International Normalized Ratio in a dose-related fashion. The cell-based coagulation model represents the most cohesive scientific framework on which we can understand and manage coagulation during critical bleeding.

Association between functional iron deficiency and reactive thrombocytosis in hospitalised patients: a case-control study

The association of deficiency in total body iron with an increased risk of reactive thrombocytosis is well known, but whether 'functional iron deficiency' is also associated with reactive thrombocytosis is unknown. This retrospective case-control study assessed the relationships between functional iron deficiency, reactive thrombocytosis and risk of thromboembolism. A total of 150 patients with reactive thrombocytosis (platelet count >400 x 10⁹/l) and 343 controls (platelet count <400 x 10⁹/l) were selected from the hospital laboratory database system. Patients with haematological disease or recent chemotherapy were excluded. Reactive thrombocytosis, infection, and an elevated C-reactive protein (CRP) concentration were all significantly more common in patients with functional iron deficiency than in those without functional iron deficiency (all P <0.01). After adjusting for infection and CRP concentration, functional iron deficiency was the only marker of iron status significantly associated with reactive thrombocytosis (odds ratio 1.66, 95% confidence interval 1.10-2.75; P=0.048). Thromboembolic events occurred in 32 patients (6.6%). This was not significantly associated with functional iron deficiency. Our results suggest that in patients without haematological malignancy or recent chemotherapy there might be a link between functional iron deficiency and reactive thrombocytosis. Whether treating patients with functional iron deficiency with intravenous iron corrects reactive thrombocytosis without inducing infection remains uncertain, but merits further investigation.

[Iron deficiency, thrombocytosis and thromboembolism]

Iron deficiency, the most common nutritional deficiency worldwide, is often associated with reactive thrombocytosis. Although secondary thrombocytosis is commonly considered to be harmless, there is accumulating evidence that elevated platelet counts, especially in the setting of iron deficiency, can lead to an increased thromboembolic risk in both arterial and venous systems. Here we present the mechanisms of iron deficiency-induced thrombocytosis and summarize its clinical consequences especially in patients with inflammatory bowel diseases, chronic kidney disease or cancer. We hypothesize that iron deficiency is an underestimated thromboembolic risk factor, and that iron replacement therapy can become an effective preventive strategy in a variety of clinical settings.

Surveillance and Early Management of Deep Vein Thrombosis Decreases Rate of Pulmonary Embolism in High-Risk Trauma Patients

BACKGROUND

Venous duplex ultrasound (VDU) is the modality of choice for surveillance of venous thromboembolism (VTE), but there is controversy about its appropriate implementation as a screening method. We hypothesize that VDU surveillance in trauma patients at high risk for VTE decreases the rate of pulmonary embolism (PE).

STUDY DESIGN

One thousand two hundred and eighty-two trauma ICU admissions were screened with Greenfield's Risk Assessment Profile from August 2011 to September 2014. Four hundred and two patients were identified as high risk for VTE (Risk Assessment Profile ≥10). Those who received weekly VDU to evaluate for deep vein thrombosis (n = 259 [64%]) were compared with those who did not (n = 143 [36%]). Parametric data are reported as mean ± SD and nonparametric data are reported as median (interquartile range). Statistical significance was determined at an α level of 0.05.

RESULTS

The overall study population was 47 ± 19 years old and 75% were male, 78% of injuries were blunt mechanism, Injury Severity Score was 28 ± 13, Risk Assessment Profile was 14 ± 4, and mortality was 14.3%. Deep vein thrombosis rate was 11.6% (n = 30) in the surveillance group vs 2.1% (n = 3) in the non-surveillance group (p < 0.001). Deep vein thromboses detected in the surveillance group were managed with systemic anticoagulation (43%) or with IVC filter placement (57%). In the surveillance group, the PE rate was 1.9% (n = 5) vs 7.0% (n = 10) in the non-surveillance group (p = 0.014).

CONCLUSIONS

Trauma patients at high risk for VTE and who received VDU surveillance and early management of deep vein thrombosis have decreased rates of pulmonary embolism.

Platelet Count and Major Bleeding in Patients Receiving Vitamin K Antagonists for Acute Venous Thromboembolism, Findings From Real World Clinical Practice

The outcome of patients with acute venous thromboembolism (VTE) and abnormal platelet count (PlC) at baseline has not been consistently studied. In real-world clinical practice, a number of patients with abnormal PlC receive vitamin K antagonists (VKAs) to treat acute VTE despite their higher risk of bleeding.We used the Registro Informatizado de Enfermedad TromboEmbólica registry database to compare the rate of major bleeding in patients receiving VKA for long-term therapy of acute VTE according to PlC levels at baseline. Patients were categorized as having very low (<100,000/μL), low (100,000-150,000/μL), normal (150,000-300,000/μL), high (300,000-450,000/μL), or very high (>450,000/μL) PlC at baseline.Of 55,369 patients recruited as of January 2015, 37,000 (67%) received long-term therapy with VKA. Of these, 611 patients (1.6%) had very low PlC, 4006 (10.8%) had low PlC, 25,598 (69%) had normal PlC, 5801 (15.6%) had high PlC, and 984 (2.6%) had very high PlC at baseline. During the course of VKA therapy (mean, 192 days), there were no differences in the duration or intensity (as measured by international normalized ratio levels) of treatment between subgroups. The rate of major bleeding was 3.6%, 2.1%, 1.9%, 2.1%, and 3.7%, respectively, and the rate of fatal bleeding was 0.98%, 0.17%, 0.29%, 0.34%, and 0.50%, respectively. Patients with very low or very high PlC levels were more likely to have severe comorbidities.We found a nonlinear "U-shaped" relationship between PlC at baseline and major bleeding during therapy with VKA for VTE. Consistent alteration of PlC values at baseline suggested a greater frailty.

Venous Thromboembolism in Patients With Thrombocytopenia: Risk Factors, Treatment, and Outcome

Background:

Venous thromboembolism (VTE) is a frequent and potentially lethal condition. Venous thrombi are mainly constituted of fibrin and red blood cells, but platelets also play an important role in VTE formation. Information about VTE in patients with thrombocytopenia is, however, missing.

Objectives:

To identify VTE risk factors and describe treatment and outcome (bleeding episodes and mortality) in patients with thrombocytopenia.

Patients/Methods:

Patients with thrombocytopenia (platelet count <100 × 109/L) admitted to Odense University Hospital, Denmark, between April 2000 and April 2012 were included. Fifty cases had experienced VTE. Controls without VTE were matched 3:1 with cases on sex and hospital department. Medical records were examined, and data were analyzed using conditional logistic regression.

Results:

In multivariate analysis, platelet count <50 × 109/L (odds ratio [OR] 0.22, P < .05) and chronic liver disease (OR 0.05, 95% confidence interval [CI] 0.01-0.58) reduced the risk of VTE. Surgery (OR 6.44, 95% CI 1.37-30.20) and previous thromboembolism (OR 6.16, 95% CI 1.21-31.41) were associated with an increased VTE risk. Ninety-two percent of cases were treated with anticoagulants. There was no difference in bleeding incidence between cases and controls.

Conclusions:

Several known VTE risk factors also seems to apply in patients with thrombocytopenia. Also, patients with thrombocytopenia may be VTE risk stratified based on platelet count and comorbidities. Finally, patients having thrombocytopenia with VTE seem to be safely treated with anticoagulants without increased occurrence of bleeding.

Incidence of Venous Thromboembolism and Benefits and Risks of Thromboprophylaxis After Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

Optimal thromboprophylaxis after cardiac surgery is uncertain. This systematic review aimed to define the incidence and risk factors for deep vein thrombosis (DVT), fatal and nonfatal pulmonary embolism (PE), and assess whether venous thromboembolism (VTE) prophylaxis was effective in reducing VTE without complications after cardiac surgery.

Methods and Results

Two reviewers independently searched and assessed the quality and outcomes of randomized, controlled trials (RCTs) and observational studies on VTE after cardiac surgery in the MEDLINE, EMBASE, and Cochrane controlled trial register (1966 to December 2014). Sixty‐eight studies provided data on VTE outcomes or complications related to thromboprophylaxis after cardiac surgery. The majority of the studies were observational studies (n=49), 16 studies were RCTs, and 3 were meta‐analyses. VTE prophylaxis was associated with a reduced risk of PE (relative risk [RR], 0.45; 95% confidence interval [CI], 0.28–0.72; P=0.0008) or symptomatic VTE (RR, 0.44; 95% CI, 0.28–0.71; P=0.0006) compared to the control without significant heterogeneity. Median incidence (interquartile range) of symptomatic DVT, PE, and fatal PE were 3.2% (0.6–8.1), 0.6% (0.3–2.9), and 0.3% (0.08–1.7), respectively. Previous history of VTE, obesity, left or right ventricular failure, and prolonged bed rest, mechanical ventilation, or use of a central venous catheter were common risk factors for VTE. Bleeding or cardiac tamponade requiring reoperation owing to pharmacological VTE prophylaxis alone, without systemic anticoagulation, was not observed.

Conclusions

Unless proven otherwise by adequately powered RCTs, initiating pharmacological VTE prophylaxis as soon as possible after cardiac surgery for patients who have no active bleeding is highly recommended.

Association Between Anemia and Cerebral Venous Thrombosis: Case-Control Study

BACKGROUND AND PURPOSE

Anemia is often considered to be a risk factor for cerebral venous thrombosis (CVT), but this assumption is mostly based on case reports. We investigated the association between anemia and CVT in a controlled study.

METHODS

Unmatched case-control study: cases were adult patients with CVT included in a single-center, prospective database between July 2006 and December 2014. Controls were subjects from the control population of the Multiple Environmental and Genetic Assessment of Risk Factors for Venous Thrombosis (MEGA) study. Anemia was defined according to World Health Organization criteria: nonpregnant women hemoglobin<7.5 mmol/L, pregnant women<6.9 mmol/L, and men<8.1 mmol/L. We used logistic regression analysis, adjusting for age, sex, malignancy, oral contraceptive use, and pregnancy/puerperium.

RESULTS

We included 152 cases and 2916 controls. Patients with CVT were younger (mean age, 40 versus 48 years) and more often women (74% versus 53%) than controls. Anemia was more frequent in cases (27.0%) than in controls (6.5%; P<0.001). Anemia was associated with CVT, both in univariate analysis (odds ratio, 5.3; 95% confidence interval [CI], 3.6-7.9) and after adjustment for potential confounders (adjusted odds ratio, 4.4; 95% CI, 2.8-6.9). Hemoglobin as a continuous variable was inversely associated with CVT (adjusted odds ratio per 1 mmol/L change 0.53; 95% CI, 0.42-0.66). Stratification by sex showed a stronger association between anemia and CVT in men (adjusted odds ratio, 9.9; 95% CI, 4.1-23.8) than in women (3.6; 95% CI, 2.1-6.0).

CONCLUSION

Our data suggest that anemia is a risk factor for CVT.

Post splenectomy related pulmonary hypertension

Splenectomy predisposes patients to a slew of infectious and non-infectious complications including pulmonary vascular disease. Patients are at increased risk for venous thromboembolic events due to various mechanisms that may lead to chronic thromboembolic pulmonary hypertension (CTEPH). The development of CTEPH and pulmonary vasculopathy after splenectomy involves complex pathophysiologic mechanisms, some of which remain unclear. This review attempts to congregate the current evidence behind our understanding about the etio-pathogenesis of pulmonary vascular disease related to splenectomy and highlight the controversies that surround its management.

Predictors of an Increased in Vitro Thrombotic and Bleeding Tendency in Critically Ill Trauma and Non-Trauma Patients

Trauma patients are at a high risk of both bleeding and thromboembolism. This study assessed whether conventional coagulation blood tests were reliable predictors of an increased in vitro thrombotic and bleeding tendency of trauma and non-trauma patients. Conventional coagulation blood tests and thromboelastographs of 63 trauma and 63 randomly selected, critically ill non-trauma patients were compared. Increased in vitro thrombotic and bleeding tendencies were defined by a maximum amplitude >72 mm or an angle >74° on the thromboelastograph and a maximum amplitude < 54 mm or an angle <47°, respectively. In vitro thrombotic tendency was more common than bleeding tendency and this was not different between the critically ill trauma and non-trauma patients (59% versus 67% with thrombotic tendency, P=0.461; 11% versus 10% with bleeding tendency, respectively, P=0.999). Thrombocytopenia (<150 × 109 /l) and low fibrinogen concentrations (<2 g/l) were the only two factors associated with an increased in vitro bleeding tendency (both P=0.001) and thrombocytopenia was the only factor associated with a lower risk of in vitro thrombotic tendency (21% versus 75%, P=0.001). Platelet counts (Pearson's correlation coefficient [ r]: 0.59, P=0.001) and fibrinogen concentrations ( r 0.61, P=0.001) both had a relatively linear association with maximum amplitude of the thromboelastograph. Prolonged International Normalized Ratio (>1.5) and activated Partial Thromboplastin Time (>40 seconds) were, however, not significantly associated with an increased in vitro thrombotic or bleeding tendency. In conclusion, in vitro thrombotic tendency was more common than bleeding tendency in critically ill trauma and non-trauma patients. Platelet counts and fibrinogen concentrations were better predictors of increased in vitro thrombotic and bleeding risks than International Normalized Ratio or activated Partial Thromboplastin Time.

Platelet count measured prior to cancer development is a risk factor for future symptomatic venous thromboembolism: the Tromsø Study

Background

Elevated platelet count is associated with risk of venous thromboembolism in cancer patients initiating chemotherapy. It is not known whether this risk by platelet count is causal or merely reflects the malignant disease. We investigated whether pre-cancer platelet count alone or together with high leukocyte count was associated with risk of venous thromboembolism in subjects who did and did not develop cancer during follow-up in a population-based cohort study.

Methods

Platelet count and other baseline characteristics were measured in 25160 initially cancer-free subjects who participated in the Tromsø Study in 1994–1995. Incident cancer and symptomatic venous thromboembolism events were registered up to December 31^st, 2009. Multivariable Cox regression models were used to calculate hazard ratio for venous thromboembolism across categories of platelet count (<40^th, 40–80^th, and >80^th percentile) with 95% confidence interval.

Results

During follow-up, 2082 subjects were diagnosed with cancer. Platelet count was measured on average 8.3 years before the cancer diagnosis. There were 129 venous thromboembolism events in the cancer cohort (13.5 per 1000 person-years) and 377 in the non-cancer cohort (1.2 per 1000 person-years). In cancer patients, pre-cancer platelet count above the 80^th percentile (≥295×10⁹/L) was associated with a 2-fold higher risk of venous thromboembolism (Hazard ratio: 1.98, 95% confidence interval 1.21–3.23) compared to platelet count below the 40^th percentile (<235×10⁹/L). Concomitant high platelet and leukocyte counts showed a synergistic effect on the VTE risk. In cancer-free subjects, no association was found.

Comment

In conclusion, pre-cancer platelet count was associated with risk of symptomatic venous thromboembolism in cancer patients, but not in cancer-free subjects. Our findings suggest that platelet count and platelet-leukocyte interactions may play a role in the pathogenesis of cancer-related venous thromboembolism.

Splenectomy is modifying the vascular remodeling of thrombosis

Background

Splenectomy is a clinical risk factor for complicated thrombosis. We hypothesized that the loss of the mechanical filtering function of the spleen may enrich for thrombogenic phospholipids in the circulation, thereby affecting the vascular remodeling of thrombosis.

Methods and Results

We investigated the effects of splenectomy both in chronic thromboembolic pulmonary hypertension (CTEPH), a human model disease for thrombus nonresolution, and in a mouse model of stagnant flow venous thrombosis mimicking deep vein thrombosis. Surgically excised thrombi from rare cases of CTEPH patients who had undergone previous splenectomy were enriched for anionic phospholipids like phosphatidylserine. Similar to human thrombi, phosphatidylserine accumulated in thrombi after splenectomy in the mouse model. A postsplenectomy state was associated with larger and more persistent thrombi. Higher counts of procoagulant platelet microparticles and increased leukocyte–platelet aggregates were observed in mice after splenectomy. Histological inspection revealed a decreased number of thrombus vessels. Phosphatidylserine‐enriched phospholipids specifically inhibited endothelial proliferation and sprouting.

Conclusions

After splenectomy, an increase in circulating microparticles and negatively charged phospholipids is enhanced by experimental thrombus induction. The initial increase in thrombus volume after splenectomy is due to platelet activation, and the subsequent delay of thrombus resolution is due to inhibition of thrombus angiogenesis. The data illustrate a potential mechanism of disease in CTEPH.

Patient factors associated with frequent clotting of dialysers during haemodiafiltration in critically ill patients: a post hoc analysis of a randomised controlled study

Continuous haemodiafiltration (CVVHDF) is the main form of renal replacement therapy in critically ill patients with severe acute kidney injury. Clotting of the dialysers during CVVHDF is frequent, because most patients with acute kidney injury have an increased risk of bleeding and cannot be systemically anticoagulated. Using data from a randomised controlled trial comparing the efficiency of CVVHDF by placing the dialysis catheter tip at the right atrium or superior vena cava, this study assessed the patient factors associated with an increased risk of frequent clotting of the dialysers-defined by >1 dialysers clotted per day of CVVHDF. Of the 94 patients included in this study, a higher body mass index, a higher platelet count and a lower International Normalized Ratio were associated with an increased risk of frequent clotting of dialysers in the univariate analyses. Use of aspirin or clopidogrel, causes of acute kidney injury and daily dose of unfractionated heparin used were not significantly associated with the risk of frequent clotting of dialysers. In the multivariate parsimony model, only a high body mass index (odds ratio 1.06 per point increment, 95% confidence interval 1.01 to 1.13; P=0.036) and a high platelet count (odds ratio 1.84 per 100x10(9)/l increment, 95% confidence interval 1.17 to 2.91; P=0.009), both in a relatively linear fashion, were independently associated with an increased risk of frequent clotting of dialysers. Optimising the position of the tip of the dialysis catheter may be particularly important for patients with a high body mass index and platelet count in order to reduce frequent clotting of dialysers during CVVHDF.

Hematologic Complications

Critically ill patients are at high risk of developing various hematologic complications that may be present on admission or occur during their stay in the Intensive Care Unit (ICU). Often times the etiology of specific hematologic abnormalities is unclear and the diagnosis may be challenging due to the complexity of critically ill patients. This chapter will focus on diagnosis and management of the most commonly encountered hematologic problems in the critically ill such as anemia, neutropenia, thrombocytopenia, coagulopathy and thrombotic complications, with specific focus on diagnosis and management of these conditions.

Seasonal variation of platelets in a cohort of Italian blood donors: a preliminary report

Background

Since available data are not univocal, the aim of this study was to explore the existence of a seasonal variation in platelet count.

Methods

The study was based on the database of the Italian Association of Blood Volunteers (AVIS), section of Ferrara, Italy, 2001–2010. Hematological data (170,238 exams referring to 16,422 donors) were categorized into seasonal and monthly intervals, and conventional and chronobiological analyses were applied.

Results

Platelets and plateletcrit were significantly higher in winter-autumn, with a main peak in December-February (average +3.4% and +4.6%, respectively, P <0.001 for both).

Conclusions

Although seasonal variations have been reported for several acute cardiovascular diseases, it is extremely unlikely that such a slight increase in platelet count in winter alone may be considered as a risk factor.

Eosinopenia as a predictor of unexpected re-admission and mortality after intensive care unit discharge

Predicting unexpected intensive care unit (ICU) re-admission and mortality after critical illness is difficult. This study assessed the associations between eosinopenia on the day of ICU discharge and outcomes after critical illness. This retrospective cohort study involved a total of 1446 critically ill patients who survived their first ICU admission between January 2009 and March 2010 in a multidisciplinary ICU in Western Australia. Eosinopenia was defined as eosinophil count <0.01×109/l and the date of censor for survival was 31 October 2011. Of the 1446 patients included in the study, 106 patients (7.3%) were re-admitted to the ICU during the same hospitalisation and 178 patients died (12.3%) after ICU discharge. Eosinopenia at ICU discharge occurred in 130 patients (9.7%) and was more common among those who were subsequently re-admitted (18.6 vs 8.6%) or died after ICU discharge (22.5 vs 7.5%). Eosinopenia remained associated with ICU re-admission (odds ratio 2.50, 95% confidence interval 1.38-4.50; P=0.002) and post-ICU mortality (hazard ratio 2.65, 95% confidence interval 1.77-3.98; P=0.001) after adjusting for age, gender, nocturnal discharge, neutrophil count at ICU discharge, elective surgical admission, Sequential Organ Failure Assessment scores, Acute Physiology and Chronic Health Evaluation II predicted mortality and chronic medical diseases. Eosinopenia at ICU discharge explained about 8.4% of the variability and was the third most important factor in explaining the variability in survival after ICU discharge. In summary, eosinopenia at ICU discharge was associated with an increased risk of unexpected ICU re-admission and post-ICU mortality.