Thrombocytosis after trauma: incidence, aetiology, and clinical significance

Distinctive patterns of sequential platelet counts following blunt traumatic brain injury predict outcomes

OBJECTIVE

To determine the role of platelet counts in the context of the decision to treat patients with non-compounded, non-surgically-treated blunt traumatic brain injury (NCNS-bTBI) with anticoagulants/antiaggregants.

METHODS

A retrospective analysis of 141 anticoagulants/antiaggregants-naïve patients with NCNS-bTBI. Changes in PT-INR and prolonged aPTT were examined and correlated with Marshall and Rotterdam scores, clinical and neuroradiological outcomes.

RESULTS

Three groups of platelet counts were identified. Group 1 (83% of patients) had normal platelet counts (150,000-450,000 platelets/mm3) from admission to discharge. Group 2 (13%) developed transient thrombocytopenia (<150,000 platelets/mm3) 2-3 days post-trauma. Group 3 (4%) developed extreme thrombocytosis > 1,000,000/mm3 platelets 6-9 days post-trauma. Neither acute coagulopathy of trauma nor progressive hemorrhagic insults followed NCNS-bTBI. Moreover, while patients with thrombocytosis/extreme thrombocytosis presented with a worse Glasgow coma score (GCS) on admission (8.8 ± 2.9 vs. 13 ± 2, p < 0.01) and had longer hospitalization (13.5 ± 10.4 vs. 4.5 ± 2.1 days), their improvement at discharge was the highest (delta GCS, 4 ± 2.8 vs. 1.2 ± 2.1, p = 0.05). Traumatic subarachnoid hemorrhage was associated with isolated thrombocytosis and 'best improvement.' No thromboembolic or hemorrhagic complications occurred.

CONCLUSION

NCNS-bTBI, thrombocytosis was correlated with better outcomes and was not associated with an increased risk for developing thromboembolism or hemorrhage, precluding the immediate need for any additional antiaggregates.

Haemostasis and Inflammatory Parameters as Potential Diagnostic Biomarkers for VTE in Trauma-Immobilized Patients

Venous thromboembolism (VTE), which encompasses deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major public health concern due to its high incidences of morbidity and mortality. Patients who have experienced trauma with prolonged immobilization are at an increased risk of developing VTE. Plasma D-dimer levels have been known to be elevated in trauma patients, and they were closely correlated with the number of fractures. In other words, plasma D-dimer levels cannot be used as the only indicator of VTE in trauma cases. Given the limitations, further study is needed to explore other potential biomarkers for diagnosing VTE. To date, various established and novel VTE biomarkers have been studied in terms of their potential for predicting VTE, diagnostic performance, and improving clinical therapy for VTE. Therefore, this review aims to provide information regarding classic and essential haemostasis (including prothrombin time (PT), activated partial thromboplastin time (aPTT), D-dimer, fibrinogen, thrombin generation, protein C, protein S, antithrombin, tissue factor pathway inhibitor, and platelet count) and inflammatory biomarkers (C-reactive protein, erythrocyte sedimentation rate, and soluble P-selectin) as potential diagnostic biomarkers that can predict the risk of VTE development among trauma patients with prolonged immobilization. Thus, further advancement in risk stratification using these biomarkers would allow for a better diagnosis of patients with VTE, especially in areas with limited resources.

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.

Designing a Scoring System for Differential Diagnosis From Reactive Thrombocytosis and Essential Thrombocytosis

Background: Thrombocytosis is a common finding in hospitalized patients and is of two main types, essential thrombocytosis (ET) and reactive thrombocytosis (RT). It is important to distinguish the two due to increased risk of developing marrow fibrosis, acute leukemia, and thrombosis in the former. Molecular studies are the main tools to differentiate the two but are not available in all hospitals. We aimed to design a highly sensitive scoring system using routine lab data to classify thrombocytosis as essential or reactive.

Methods: A total of 145 patients were enrolled in this study. Potential predictors included patient demographics and clinical laboratory parameters. Receiver operating characteristic curve analysis was used to decide the optimal cutoff level. Multivariate logistic regression with forward model selection method was performed to decide the predictors.

Results: The risk scores by multivariate analysis were as follows: 1 point for WBC > 13,500/μL; 2.5 points for Hb > 10.9 g/dL; 3 points for platelet count > 659,000/μL; and 2 points for MPV > 9.3 fL. The cut off value was set as 4.5 points, and sensitivity of 91.1% and specificity of 75.8% were noted.

Conclusion: In this study, we investigated lab data and developed a high-sensitivity convenient-to-use scoring system to differentiate ET from RT. The scoring system was assigned to the resulting model to make it more economical, simple, and convenient for clinical practice.

Platelet-to-red blood cell ratio and mortality in bleeding trauma patients: A systematic review and meta-analysis

BACKGROUND

In traumatic bleeding, transfusion practice has shifted toward higher doses of platelets and plasma transfusion. The aim of this systematic review was to investigate whether a higher platelet-to-red blood cell (RBC) transfusion ratio improves mortality without worsening organ failure when compared with a lower ratio of platelet-to-RBC.

METHODS

Pubmed, Medline, and Embase were screened for randomized controlled trials (RCTs) in bleeding trauma patients (age ≥16 years) receiving platelet transfusion between 1946 until October 2020. High platelet:RBC ratio was defined as being the highest ratio within an included study. Primary outcome was 24 hour mortality. Secondary outcomes were 30-day mortality, thromboembolic events, organ failure, and correction of coagulopathy.

RESULTS

In total five RCTs (n = 1757 patients) were included. A high platelet:RBC compared with a low platelet:RBC ratio significantly improved 24 hour mortality (odds ratio [OR] 0.69 [0.53-0.89]) and 30- day mortality (OR 0.78 [0.63-0.98]). There was no difference between platelet:RBC ratio groups in thromboembolic events and organ failure. Correction of coagulopathy was reported in five studies, in which platelet dose had no impact on trauma-induced coagulopathy.

CONCLUSIONS

In traumatic bleeding, a high platelet:RBC improves mortality as compared to low platelet:RBC ratio. The high platelet:RBC ratio does not influence thromboembolic or organ failure event rates.

Acute and chronic hematologic implications of emergency and elective splenectomy

INTRODUCTION

Thrombocytosis and leukocytosis are common after splenectomy. The potential effect of emergency surgery on these postoperative findings is unknown. We hypothesized that emergency splenectomy leads to a more profound and persistent hematologic change as compared to elective splenectomy.

METHODS

A retrospective review was conducted of patients who underwent elective or trauma splenectomy. Records were queried for platelet (PLT) and white blood cell (WBC) count prior to splenectomy, on postoperative days 1-5, and at day 14, 1 month, 3 months, 6 months, and 1 year. Complications, including thromboembolic events, infection, need for repeat operation, and readmission within 30 days of discharge, were recorded.

RESULTS

463 patients were identified as being eligible for the study, with 173 patients in the elective cohort and 145 patients in each of the isolated trauma splenectomy and polytrauma cohorts. Both cohorts had peak thrombocytosis at week 2 postoperatively. However, polytrauma patients had a significantly higher peak platelet count (P < 0.01). The PLT:WBC ratio was lower in both trauma cohorts pre-operatively and postoperative day 1. Trauma splenectomy had a higher PLT:WBC ratio on days 2 and 3 whereas polytrauma had a lower ratio on days 4 and 5. Emergency cases had greater reoperation and infection rates, whereas elective cases were more likely to require readmission. Postoperative thromboembolic events were only higher in the polytrauma cohort.

CONCLUSIONS

While trauma splenectomy resulted in more profound postoperative leukocytosis and thrombocytosis, there was no correlation with timing of infection or risk of thromboembolic events. These findings suggest that thrombocytosis and leukocytosis may be associated with thrombotic and infectious events but their presence alone does not indicate direct risks of concomitant infection or thrombosis.

Chinese expert consensus on diagnosis and treatment of trauma-induced hypercoagulopathy

Trauma-induced coagulopathy (TIC) is caused by post-traumatic tissue injury and manifests as hypercoagulability that leads to thromboembolism or hypocoagulability that leads to uncontrollable massive hemorrhage. Previous studies on TIC have mainly focused on hemorrhagic coagulopathy caused by the hypocoagulable phenotype of TIC, while recent studies have found that trauma-induced hypercoagulopathy can occur in as many as 22.2-85.1% of trauma patients, in whom it can increase the risk of thrombotic events and mortality by 2- to 4-fold. Therefore, the Chinese People's Liberation Army Professional Committee of Critical Care Medicine and the Chinese Society of Thrombosis, Hemostasis and Critical Care, Chinese Medicine Education Association jointly formulated this Chinese Expert Consensus comprising 15 recommendations for the definition, pathophysiological mechanism, assessment, prevention, and treatment of trauma-induced hypercoagulopathy.

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.

Factors associated with ultrasound-guided water enema reduction for pediatric intussusception in resource-limited setting: potential predictive role of thrombocytosis and anemia

BACKGROUND/PURPOSE

Although ultrasound-guided hydrostatic reduction (USGHR) is increasingly used in managing pediatric intussusception, there is limited literature concerning its use in Malaysia. We aim to examine the experience and factors associated with the effectiveness of USGHR using water.

METHODS

This is a single-center retrospective observational study in a Malaysian tertiary referral center. Children with intussusception admitted between year 2012 and 2016 were included and medical records reviewed. Factors associated with success or failure of USGHR were identified using multivariable logistic regression.

RESULTS

Of the 172 cases included, 151 cases (87.8%) underwent USGHR, of whom 129 cases were successfully reduced (success rate of 85.4%). One perforation (0.7%) was reported. Age more than 3years old (aOR=7.16; 95% CI=1.07-47.94; p=0.042), anemia (aOR=10.12; 95% CI=1.12-91.35; p=0.039), thrombocytosis (aOR=11.21; 95% CI=2.06-64.33; p=0.005) and ultrasound findings of free fluid (aOR=9.39; 95% CI=1.62-54.38; p=0.012) and left-sided intussusception (aOR=8.18;95% CI=1.22-54.90, p=0.031) were independently associated with USGHR irreducibility. Symptom duration, blood in stool, vomiting and other clinical presentations, however, showed no association.

CONCLUSIONS

USGHR with water is effective in the non-operative management of pediatric intussusception. Prolonged symptom duration need not necessarily preclude USGHR. The findings of anemia and thrombocytosis as independent predictors of USGHR irreducibility deserve further study.

TYPE OF STUDY

Treatment study LEVEL OF EVIDENCE: III.

Aspirin for primary prevention of stroke in traumatic cerebrovascular injury: association with increased risk of transfusion

OBJECTIVE

Blunt traumatic extracranial carotid or vertebral artery injury (i.e., traumatic cerebrovascular injury [TCVI]) occurs in 1%-2% of all blunt trauma admissions, carries a 10% risk of thromboembolic ischemic stroke, and accounts for up to 9600 strokes annually in the US. Screening CT angiograms (CTAs) of patients with trauma has become ubiquitous in recent years, and patients with initially asymptomatic TCVI are commonly treated with antiplatelet agents to prevent stroke. Prophylaxis with antiplatelets is thought to be safer than anticoagulation, which carries a significant risk of hemorrhage in patients with trauma. However, the risk of hemorrhagic complications due to antiplatelets has not been assessed in this population.

METHODS

This is a retrospective cohort study of patients in whom a screening CTA was obtained after admission for blunt trauma at a Level 1 trauma center. Patients with CTAs indicating TCVI were treated routinely with 325 mg aspirin daily. The risk of transfusion > 24 hours after admission was compared according to CTA findings (CTA+ or CTA- for positive or negative findings, respectively) and aspirin treatment (ASA+ or ASA- for treatment or no treatment, respectively).

RESULTS

The mean overall transfusion amount (number of units of packed red blood cells [PRBCs]) was 0.9 ± 2.1 for CTA+/ASA+ patients (n = 196) and 0.3 ± 1.60 for CTA-/ASA- patients (n = 2290) (p < 0.0001). In adjusted models, the overall relative risk (RR) of PRBC transfusion was 1.70 (1.32-2.20) for CTA+/ASA+ patients compared with CTA-/ASA- patients. Among age groups, participants whose ages were 50-69 years had the greatest significantly elevated RR (1.71, 95% CI 1.08-2.72) for CTA+/ASA+ patients compared with CTA-/ASA- patients.

CONCLUSIONS

Treatment with aspirin for the prevention of stroke in patients with initially asymptomatic TCVI carries a significantly increased risk of PRBC transfusion. Future studies are needed to determine if this risk is offset by a reduced risk of ischemic stroke.

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.

Preoperative Platelet Count Predicts Lower Extremity Free Flap Thrombosis: A Multi-Institutional Experience

BACKGROUND

Thrombocytosis in patients undergoing lower extremity free tissue transfer may be associated with increased risk of microvascular complications. This study assessed whether preoperative platelet counts predict lower extremity free flap thrombosis.

METHODS

All patients undergoing lower extremity free tissue transfer at Duke University from 1997 to 2013 and at the University of Pennsylvania from 2002 to 2013 were retrospectively identified. Logistic regression was used to assess whether preoperative platelet counts independently predict flap thrombosis, controlling for baseline and operative factors.

RESULTS

A total of 565 patients underwent lower extremity free tissue transfer, with an overall flap thrombosis rate of 16 percent (n = 91). Elevated preoperative platelet counts were independently associated with both intraoperative thrombosis (500 ± 120 versus 316 ± 144 × 10/liter; p < 0.001) and postoperative thrombosis (410 ± 183 versus 320 ± 143 × 10/liter; p = 0.040) in 215 patients who sustained acute lower extremity trauma within 30 days before reconstruction. In acute trauma patients, preoperative platelet counts predicted a four-fold increased risk of intraoperative thrombosis (cutoff value, 403 × 10/liter; OR, 4.08; p < 0.001) and a two-fold increased risk of postoperative thrombosis (cutoff value, 361 × 10/liter; OR, 2.16; p = 0.005). In patients who did not sustain acute trauma, preoperative platelet counts predicted a four-fold increased risk of intraoperative thrombosis (cutoff value, 352 × 10/liter; OR, 3.82; p = 0.002).

CONCLUSIONS

Acute trauma patients with elevated preoperative platelet counts are at increased risk for lower extremity free flap complications. Prospective evaluation is warranted for guiding risk stratification and targeted treatment strategies.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, III.

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.

Similar change in platelets and leucocytes 24 h after injury is associated with septic shock a week later

BACKGROUND

Septic shock is a severe complication in polytrauma patients. Early identification of patients at risk can guide future prevention strategies. Platelets (PLTs) and leucocytes presumably play an important role in the post-injury inflammatory response. The role of early changes in PLT and leucocyte counts was investigated in search for the aetiology of the development of septic complications.

METHODS

Polytrauma patients (aged 16-80 years) admitted to the intensive care unit with an expected stay of at least 3 days were included. PLT and leucocyte counts were measured on a daily basis for 14 days.

RESULTS

A total of 41 patients were included, of whom nine (22%) developed septic shock. There was no difference in (New) Injury Severity Score or Acute Physiology and Chronic Health Evaluation II scores between patients who developed septic shock and patients who did not. Three patients died, one of them in septic shock. Patients who developed septic shock during hospital stay had lower PLTs and a slower recovery to normal PLT counts than patients without septic shock. Patients who developed either a decrease in both PLTs and leucocytes or an increase in PLTs and leucocytes in the first 24 h after trauma were more likely to develop septic shock. This correlation was not found in patients who did not develop septic shock.

CONCLUSION

A similar change in PLT and leucocyte counts in the first 24 h after trauma is associated with the development of septic shock after a week. This indicates an early interaction between PLTs and leucocytes, which needs further investigation to gain more insight in the aetiology of post-injury septic complications.

Thrombocytosis in splenic trauma: In-hospital course and association with venous thromboembolism

INTRODUCTION

Thrombocytosis is common following elective splenectomy and major trauma. However, little is known about the in-hospital course of platelet count (PC) and incidence of thrombocytosis after splenic trauma. Extreme thrombocytosis (PC>1000×10⁹) is associated with increased risk of venous thromboembolism (VTE) in primary thrombocytosis leading to the use of acetylsalicylic acid (ASA) for risk reduction, but the need for this agent in splenic trauma is undefined.

METHODS

Retrospective cohort study of all patients with splenic trauma between April 1, 2010 and March 31, 2014. The in-hospital course of PC was assessed based on splenic injury management type. The association of management type with thrombocytosis was evaluated using a multivariable logistic regression model adjusting for potential confounders. The association of thrombocytosis, extreme thrombocytosis, and ASA use for the outcome of VTE was explored.

RESULTS

156 patients were eligible, PC initially increased in all patients with the highest peak after total splenectomy. The incidence of thrombocytosis was 41.0% (64/156). Thrombocytosis was more likely following splenectomy compared with spleen preserving strategies independent of length of stay, injury grade, ISS, age and transfusion (OR 7.58, 95% CI: 2.26-25.45). Splenectomy was associated with extreme thrombocytosis (OR 10.39, 95% CI: 3.59-30.07).

CONCLUSIONS

Thrombocytosis in splenic trauma is more likely after splenectomy than with spleen preserving strategies. Splenectomy is associated with extreme thrombocytosis. There was insufficient data in our study to determine the use of ASA as primary prevention of VTE after splenic trauma.

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.

Thrombocytosis after hip and knee surgery in the rehabilitation setting: is it an occasional phenomenon? Relationship with deep venous thrombosis and functional outcome

Background

Thrombocytosis can follow surgery and has occasionally been observed after major orthopaedic surgery. The aim of the present study was to ascertain the platelet count (PLTC) change in patients admitted to a rehabilitation unit after major joint surgery and whether deep venous thrombosis (DVT) and poor outcomes occurred in those who had thrombocytosis.

Method

PLTC, red blood cells (RBC), haemoglobin (Hb), fibrinogen, and D-dimers were assessed in patients on admission and at discharge after major joint surgery. Functional outcomes were ascertained using the Barthel Scale (BS), the Functional Independence Measure (FIM) and gait evaluation. Thrombocytosis was considered to have occurred when PLTC was greater than or equal to 500 × 100⁹/L. All subjects with thrombocytosis had ultrasonography to assess DVT occurrence. The patients were divided into “young” and “old” groups according to an age cut-off of 75 years to investigate potential age-related differences.

Results

Two hundred and seventy-five patients were identified and 142 (36 M and 106 F, mean age 77.2 ± 10.7) were enrolled. Seventy-six (53.5%) underwent total hip arthroplasty (THA), 40 (51.1%) underwent hip internal fixation and 26 (18.3%) subjects underwent total knee arthroplasty (TKA). The young and old groups included 60 and 82 patients, respectively. Fifty-nine (42.4%) patients had PLTC above 400 × 100⁹/L. Of these, 28 (20.1%) had thrombocytosis with PLTC above 500 × 100⁹/L, and 15 of them (10.7%) had very high values above 600 × 100⁹/L. Increased levels of fibrinogen and D-dimers were also detected. No subject with thrombocytosis had DVT. Outcome was not affected by PLTC. At discharge, significant improvement in all functional assessments was observed in young compared to old people; gait: 2.9 ± 0.2 vs. 2.2 ± 0.8; BS: 97 ± 6.9 vs. 70.5 ± 25.6; and FIM: 116.4 ± 10.9 vs. 83.6 ± 31.2 (p < 0.004), respectively. BS and FIM mean scores were positively correlated with Hb level.

Conclusion

Elevated PLTC and thrombocytosis were not uncommon in patients after major joint surgery, but no subject developed DVT. Platelet count change did not affect the outcome. Higher age and lower haemoglobin level correlated with poorer functional recovery.

Trauma induced hypercoagulablity in pediatric patients

PURPOSE

Coagulation changes in pediatric trauma patients are not well defined. To fill this gap, we tested the hypothesis that trauma evokes a hypercoagulable response.

METHODS

A prospective observational study was conducted in hospitalized patients (age 8months to 14years) admitted for trauma or elective surgery. Informed consent was obtained from the parents and informed assent was obtained in patients 7years of age or older. Coagulation changes were evaluated on fresh whole blood using thromboelastography (TEG) and on stored plasma using assays for special clotting factors.

RESULTS

Forty three patients (22 trauma, median injury severity score =9; and 21 uninjured controls) were evaluated. For trauma vs control, prothrombin time (PT) was higher by about 10% (p<0.001), but activated partial thromboplastin time was not altered. TEG clotting time (R;p=0.005) and fibrin cross-linking were markedly accelerated (K time, alpha angle; p<0.001) relative to the control patients. d-Dimer, Prothrombin Fragment 1+2, and Plasminogen Activator Inhibitor-1 were all elevated, whereas Protein S activity was reduced (all p<0.01). Importantly, a large fraction of TEG values and clotting factor assays in the pediatric control group were outside the published reference ranges for adults.

CONCLUSION

A hypercoagulable state is associated with minor trauma in children. More work is needed to determine the functional significance of these changes and to establish normal pediatric reference ranges.

Systemic effects induced by intralesional injection of ω-conotoxin MVIIC after spinal cord injury in rats

Background

Calcium channel blockers such as conotoxins have shown a great potential to reduce brain and spinal cord injury. MVIIC neuroprotective effects analyzed in in vitro models of brain and spinal cord ischemia suggest a potential role of this toxin in preventing injury after spinal cord trauma. However, previous clinical studies with MVIIC demonstrated that clinical side effects might limit the usefulness of this drug and there is no research on its systemic effects. Therefore, the present study aimed to investigate the potential toxic effects of MVIIC on organs and to evaluate clinical and blood profiles of rats submitted to spinal cord injury and treated with this marine toxin. Rats were treated with placebo or MVIIC (at doses of 15, 30, 60 or 120 pmol) intralesionally following spinal cord injury. Seven days after the toxin administration, kidney, brain, lung, heart, liver, adrenal, muscles, pancreas, spleen, stomach, and intestine were histopathologically investigated. In addition, blood samples collected from the rats were tested for any hematologic or biochemical changes.

Results

The clinical, hematologic and biochemical evaluation revealed no significant abnormalities in all groups, even in high doses. There was no significant alteration in organs, except for degenerative changes in kidneys at a dose of 120 pmol.

Conclusions

These findings suggest that MVIIC at 15, 30 and 60 pmol are safe for intralesional administration after spinal cord injury and could be further investigated in relation to its neuroprotective effects. However, 120 pmol doses of MVIIC may provoke adverse effects on kidney tissue.

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.

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

BACKGROUND

It is uncertain whether reactive thrombocytosis is associated with an increased risk of venous thromboembolism. This study assessed the incidence of reactive thrombocytosis, defined as platelet count ≥ 500 × 10(9)  L(-1) , at intensive care unit discharge and its association with subsequent venous thromboembolism.

METHODS AND RESULTS

This cohort study involved linkage of routinely collected intensive care unit, laboratory, radiology and death registry data of critically ill patients admitted to the intensive care unit between January 2009 and March 2010. The census date for survival and radiologically confirmed venous thromboembolism was 31 October 2011. Of the 1446 patients who survived to intensive care unit discharge, 139 patients had reactive thrombocytosis (9.6%, 95% confidence interval [CI] 8.2-11.2%). Twenty-nine patients developed venous thromboembolism after discharge (2%, 95% CI 1.4-2.9%; 67 per 100 person-years, 95% CI 45-97) and the median time to develop venous thromboembolism was 25 days (interquartile range 8-148). Reactive thrombocytosis was associated with an increased risk of subsequent venous thromboembolism (hazard ratio 5.3, 95% CI 1.7-16.4), after adjusting for other covariates. Platelet counts explained about 34% of the variability in the risk of venous thromboembolism and had a relatively linear relationship with the risk of venous thromboembolism when the platelet counts were > 400 × 10(9)  L(-1) . Venous thromboembolism after intensive care unit discharge was associated with an increased risk of mortality (hazard ratio 2.0, 95% CI 1.1-3.9), after adjusting for reactive thrombocytosis.

CONCLUSIONS

Reactive thrombocytosis during the recovery phase of critical illness was associated with an increased risk of subsequent venous thromboembolism.

Postsplenectomy reactive thrombocytosis

Thrombocytosis is frequently encountered as an incidental laboratory finding. The most common etiology is reactive (secondary) thrombocytosis due to infections, trauma, surgery, or occult malignancy. Even though thrombocytosis is benign and self-limiting in most cases, it can result in hemorrhage or thrombosis. The hypercoagulable state is characterized by episodes of thrombosis and can be due to inherited or acquired conditions. Extreme thrombocytosis may result in thrombotic events such as acute myocardial infarction, mesenteric vein thrombosis, and pulmonary embolism. It is important for physicians to be familiar with the complications associated with thrombocytosis. Postsplenectomy reactive thrombocytosis has an incidence of about 75% to 82%. Thrombosis in association with elevated platelet count after splenectomy is well recognized, with an incidence of approximately 5%. This case report describes a 61-year-old patient who underwent emergent splenectomy and presented 1 week later with acute ST segment elevation myocardial infarction. Severe thrombocytosis, which was not present prior to splenectomy, was noted, and a diagnosis of reactive thrombocytosis was initially made. Involvement of the right coronary artery led to emergent percutaneous transluminal coronary angioplasty. Essential thrombocytosis was considered when treatment with hydroxyurea failed to lower the platelet count. A review of arterial and venous thrombosis in patients with severe thrombocytosis is presented, and the approach to the management of such patients is discussed.

In vitro thrombotic tendency of reactive thrombocytosis in critically ill patients: a prospective case-control study

It is uncertain whether reactive thrombocytosis is associated with an increased risk of thrombosis. This prospective case-control study assessed the in vitro thrombotic tendency of patients with reactive thrombocytosis. Forty-eight patients with reactive thrombocytosis, defined by platelet count >500x10(9)/l and 55 similar, randomly selected critically ill patients who did not have reactive thrombocytosis were considered. In vitro thrombotic tendency in both groups of patients was assessed using maximal amplitude (normal range 54 to 72 mm) and alpha angle (normal range 47 to 74°) on the thromboelastograph. The associations between reactive thrombocytosis and C-reactive protein, the coagulation profile and Sequential Organ Failure Assessment score were also evaluated. Patients with reactive thrombocytosis had an associated increased in vitro thrombotic tendency (maximal amplitude 77 vs 69 mm, mean difference 8 mm, 95% confidence interval 4.9 to 10.9, P=0.001), a higher fibrinogen concentration (7.2 vs 5.8 g/l, P=0.003), and a higher incidence of infection requiring antibiotics (50 vs 27%, P=0.025) compared to patients without thrombocytosis. Platelet count had a relatively linear relationship with the maximal amplitude and the alpha angle of the thromboelastograph tracing (Pearson correlation coefficient: 0.53, P=0.001). In the multivariate analysis, only reactive thrombocytosis (odds ratio 5.9, 95% confidence interval 1.3-27.8, P=0.025) and activated partial thromboplastin time (odds ratio 0.93 per second increment, 95% confidence interval 0.87 to 0.99, P=0.016) were significantly associated with a strong in vitro thrombotic tendency. In summary, reactive thrombocytosis was associated with infection requiring antibiotics and evidence of increased in vitro thrombotic tendency in critically ill patients.

Molecular biomarker of inflammatory response is associated with rebleeding in spontaneous intracerebral hemorrhage

BACKGROUND AND PURPOSE

Rebleeding in spontaneous intracerebral hemorrhage (ICH) is a major cause of morbidity and mortality among stroke survivors. Due to the links between inflammation and rebleeding, we hypothesized that the biomarkers of inflammation are associated with the pathogenesis of rebleeding in ICH. We sought to investigate whether these biomarkers and clinical variables on admission can provide prognostic information on the risk of rebleeding.

METHODS

This prospective study enrolled 59 consecutive patients with spontaneous ICH. We determined the concentrations of interleukin-10 (IL-10), intercellular adhesion molecule-1, and complement 3 in blood samples obtained on admission.

RESULTS

Univariate analysis indicated that hematoma volume, leukocyte count, hydrocephalus, and plasma IL-10 levels were associated with rebleeding. Multivariate logistic regression analysis indicated that hydrocephalus (95% CI of OR, 1.6-26.7) and IL-10 (95% CI of OR, 1.03-1.22) were independently associated with an increased probability of rebleeding.

CONCLUSION

These data suggest that IL-10, a molecular biomarker of inflammatory response in the early acute phase of ICH, is associated with subsequent rebleeding.

Progressive postinjury thrombocytosis is associated with thromboembolic complications

BACKGROUND

Our previous investigation demonstrated that despite routine chemoprophylaxis, thrombelastography, which is a comprehensive test measuring the viscoelastic properties of blood, identified a hypercoagulable state in a cohort of critically ill surgical patients that was associated with thromboemobolic events. Furthermore, because thrombelastography allows for the comprehensive assessment of coagulation status, this work suggested that platelet hyperactivity is a component of the hypercoagulable state. We hypothesized that progressive postinjury thrombocytosis contributes to a hypercoagulable state that is associated with thrombelastography.

METHODS

One thousand four hundred and forty severely injured patients surviving >48 h were entered into a database prospectively over 12 years. The variables that were evaluated in associated with thrombocytosis (platelet count >450,000) included age, Injury Severity Score, packed red blood cell transfusions in 12 h, and thromboemobolic complications (TE) (deep venous thrombosis, pulmonary embolus, mesenteric thrombosis, stroke, and arterial thrombosis). The time frame for the development of thrombocytosis was assessed at greater or less than 7 days postinjury. Logistic regression was used to identify the independent variables predictive of thrombocytosis and to adjust the association of thrombocytosis with TE for other risk factors. C-statistic was used to assess the discriminative power of thrombocytosis for prediction of TE.

RESULTS

The mean age was 37.4 ± 0.4 years. The Injury Severity Score was 29.3 ± 0.3, and mean red blood cell transfusions in 12 h was 4.4 ± 0.2 units. Injury via blunt force occurred in 76% of patients, and 72% of patients were male. Thrombocytosis was identified in 447 (31%) patients and was noted almost exclusively >7 days postinjury (98%). TE developed in 35 (8%) of the 447 patients with thrombocytosis, compared with 45 (4.5%) of the remaining 993 patients who did not develop thrombocytosis. Persistent thrombocytosis >7 days was associated with TE (P > .0001). Logistic regression analysis indicated that when adjusted for intensive care unit duration of stay, transfusions, age, and Injury Severity Score, patients with sustained thrombocytosis more than 3 days were noted to have a 1.4 × increased risk of TE (odds ratio, 1.12; 95% confidence interval, 1.04-1.2; P = .002; C-statistic = 0.82).

CONCLUSION

Persistent thrombocytosis in critically injured patients receiving routine chemoprophylaxis is associated with thrombotic complications. Subsequent investigation is warranted to differentiate enzymatic from platelet hypercoagulability to ascertain the role of antiplatelet therapy for prevention of TE.

Acquired thrombotic risk factors in the critical care setting

Acquired thrombotic risk factors include a variety of noninherited clinical conditions that can predispose an individual to an increased risk for venous thromboembolism. For patients in a critical care setting, certain acquired risk factors represent chronic conditions that the patients may have had before the current acute illness (e.g., malignancy, various cardiovascular risk factors, certain medications), whereas others may be directly related to the reason the patient is in an intensive care unit or the patient's management there (e.g., postoperative state, trauma, indwelling vascular access, certain medications). Optimal thromboprophylactic strategies depend on individual patient risk profiles including an assessment of the specific clinical setting. Treatment for patients with acquired thrombotic risk factors includes anticoagulant therapy and, if possible, resolution of the acquired risk factor(s). Heparin-induced thrombocytopenia represents a unique clinical situation in which all sources of heparin must be discontinued and the patient started on an alternative anticoagulant (e.g., a direct thrombin inhibitor) in the acute setting. The duration of anticoagulant therapy would vary depending on the specific clinical setting.

Extreme Thrombocytosis in Trauma Patients: Are Antiplatelet Agents the Answer?

The purpose of this study was to review the incidence of extreme thrombocytosis (ExT) (platelet count 1,000,000/μL or greater) in trauma patients and to examine the role of antiplatelet agents in its treatment. The Los Angeles County Medical Center trauma registry was used to obtain injury demographics, medications, and daily platelet counts for injured patients 16 years of age or older admitted between July 2005 and February 2008. Of 6,985 total trauma patients admitted during the study period, 95 developed ExT (1.4%). Average age was 29 years (range, 16-63 years), 89 per cent were male, 44 per cent had penetrating trauma, and mean Injury Severity Score was 24 (range, 1-57). Of the 95 patients with ExT, 41 were treated with aspirin (43%) and 54 were not (57%). The two groups did not differ with regard to basic demographics, injury patterns, vitals on admission, or splenectomy rate (34 vs 20%, P = 0.13). After adjusting for maximum platelet counts and duration of ExT, there was no difference between the treated and untreated groups in terms of mortality, complications, and intensive care unit or hospital lengths of stay. The incidence of ExT is approximately 1.4 per cent in trauma patients. Antiplatelet therapy does not affect ExT patient outcome. Further prospective studies are warranted.

What is the significance of thrombocytosis in patients with trauma?

BACKGROUND

The incidence and risk factors for the development of thrombocytosis after trauma have not been well established. Although it has been suggested that the occurrence of this sequela may be associated with adverse events, there are also limited data regarding outcomes of patients developing posttraumatic thrombocytosis. The objective of this study was to determine the incidence of, risk factors for, and sequela of posttraumatic thrombocytosis.

METHODS

A retrospective review of all trauma intensive care unit (ICU) admissions between July 1998 and December 2005 identified patients with early (< or = 7 days), late, and no thrombocytosis. Bivariate analysis was used to compare the clinical and demographic characteristics with outcomes between the three patient groups.

RESULTS

A total of 3,484 patients were admitted to the ICU during the 7-year study period. After exclusions, the study population consisted of 3,286 patients. The overall incidence of thrombocytosis was 18.7%; early thrombocytosis was found in 72 patients, and late thrombocytosis was identified in 542 patients. All complications examined were significantly higher in patients with thrombocytosis. Overall, the venous thromboembolic rate was 2.4%; for patients with thrombocytosis it was 4.6% compared with 1.9% in patients without thrombocytosis. Overall mortality was 15.4%, but was significantly lower in patients with thrombocytosis (3.8% vs. 18.1%, p < 0.0001). Independent risk factors for the development of thrombocytosis included obesity, laparotomy, blunt injury, Injury Severity Score > 16, mechanical ventilation, Chest Abbreviated Injury Score > 3, and tachycardia.

CONCLUSION

Thrombocytosis is a common finding among patients with trauma admitted to the ICU. The occurrence of both early and late thrombocytosis is associated with significantly higher rates of complications, particularly venous thromboembolism. However, patients developing posttraumatic thrombocytosis may have a significantly lower mortality compared with those without this sequela of injury.

[Severe perioperative thrombocytosis in a patient undergoing lung resection]

Severe thrombocytosis (platelet count > 1,000,000 microL(-1)) is a rare, usually reactive, process and few perioperative cases have been reported. We describe the management of a patient who developed severe reactive thrombocytosis in the preoperative period before undergoing segmentectomy to remove a malignant nodule. A platelet count of 2,086,000 microL(-1) was observed during the first few days after surgery; we therefore started antiplatelet therapy to prevent thrombotic complications. We analyze the factors that might have contributed to the development of severe thrombocytosis in this case and discuss the different treatment options that may affect perioperative outcomes in these patients.

Superoxide dismutase, copper and zinc concentrations in platelet-rich plasma of pneumonia patients

BACKGROUND

The aim of this study was to analyse platelet superoxide dismutase (SOD) activities (total SOD, manganese SOD and copper zinc SOD) and copper (Cu) and zinc (Zn) concentrations during the course of community-acquired pneumonia (CAP), and to compare them between patients with normal platelet count and those who have developed reactive thrombocytosis (RT).

METHODS

Platelet count, SOD activities and Cu and Zn concentrations in platelet-rich plasma were measured in patients with CAP on admission and at discharge.

RESULTS

Post-therapeutic platelet count increased significantly from the value recorded on admission. By the end of treatment, 42% of patients developed RT. All platelet SOD activities as well as Cu concentration were significantly lower in CAP patients than in control subjects. The initial Zn concentration was greater in CAP patients compared with controls and showed a decrease at discharge. On admission, there was no difference in all SOD activities between either subgroup with normal platelet count or subgroup with RT. At discharge all SOD activities were significantly lower in patients with RT. Also, catalytic activities of those enzymes were significantly lower in both subgroups in comparison with the initial values. Post-therapeutic Cu value was lower in patients with RT in comparison with patients having normal platelet count. Zn concentration decreased significantly at discharge when compared with the initial values only in patients with RT.

CONCLUSION

The pattern of changes might be indicative of a certain role of platelets in antioxidant response during treatment in CAP patients.

Gamma-Glutamyltransferase Activity and Total Antioxidant Status in Serum and Platelets of Patients with Community-acquired Pneumonia

BACKGROUND

We undertook this study to analyze serum and platelet gamma-glutamyltransferase (GGT) activity and total antioxidant status (TAS) concentration during the course of pneumonia and to compare them between patients with normal platelet count and those who developed reactive thrombocytosis.

METHODS

Platelet count, GGT activity and TAS concentration in serum (S) and platelet (Plt) isolates were measured in 60 patients with community-acquired pneumonia (CAP) on admission and at discharge.

RESULTS

At the end of treatment, platelet count increased significantly from the value recorded on admission. By the end of treatment, 42% of patients developed reactive thrombocytosis. Serum and platelet GGT activity was higher, whereas (S)TAS was significantly lower in CAP patients than in control subjects. On admission, (Plt)TAS was significantly higher in CAP patients as compared with control subjects; at discharge, (Plt)TAS was lower in comparison with either patient admission and control subjects. GGT activity and TAS concentration in serum and platelet isolate on admission did not differ significantly between patients with and without thrombocytosis. At discharge, (S)GGT activity showed no significant changes, whereas (Plt)GGT decreased significantly in patients with thrombocytosis as compared with those without thrombocytosis. In patients with thrombocytosis, (S)TAS concentration showed no significant difference, whereas (Plt)TAS concentration measured at discharge was significantly lower in patients with thrombocytosis as compared to those with normal platelet count.

CONCLUSIONS

The pattern of changes in (Plt)GGT catalytic activity and TAS concentration might be indicative of a certain role of thrombocytosis during treatment in patients with CAP. Further investigations are necessary to clarify these changes.

Thrombocytosis in cats: a retrospective study of 51 cases (2000-2005)

Feline haematology profiles of patients presented to the University of Bristol Small Animal Hospital from January 2000 to October 2005 were evaluated for thrombocytosis (defined as a platelets count of >700x10(9)/l and confirmed on smear evaluation). Thrombocytosis was found in 79 cats (4.64% of the hospital feline population), with values ranging from 703 to 1895x10(9)/l. Signalment, clinical presentation, concurrence of other haematological abnormalities, diagnoses and outcome were evaluated in 51 cases in which complete medical records were available. Other variables (feline immunodeficiency virus/feline leukaemia virus status, thyroxine level, haemoplasma PCR, toxoplasma antibody titres) were also evaluated. No association was found between the presence of thrombocytosis and breed or gender. Gastrointestinal signs were the most common clinical presentation. Lymphopenia was the most common concurrent haematological abnormality. Based on final diagnosis reached, cats were grouped both according to the DAMNITV classification and according to the body system affected. Amongst the DAMNITV classification, inflammatory/infectious conditions were most commonly associated with thrombocytosis. According to body systems, gastrointestinal involvement was most represented, followed by endocrine cases. No association was found between the severity of thrombocytosis and outcome.

bcr/abl-negative, classic myeloproliferative disorders: diagnosis and treatment

Essential thrombocythemia, polycythemia vera, and myelofibrosis with myeloid metaplasia constitute the "classic" bcr/abl-negative myeloproliferative disorders (MPDs). Each of these MPDs represents a stem cell-derived clonal myeloproliferation with the respective features of thrombocytosis, erythrocytosis, and bone marrow fibrosis. Unlike with cases of chronic myeloid leukemia, in which the bcr/abl mutation is invariably detected, current diagnosis of essential thrombocythemia, polycythemia vera, and myelofibrosis with myeloid metaplasia is based on a consensus-driven set of clinical and laboratory criteria that have undergone substantial modification in recent times. The recent discovery of a recurrent activating Janus tyrosine kinase (JAK2) mutation (JAK2VG17F) in all 3 classic MPDs offers another opportunity for refining current diagnoses and disease classifications. In this article, we outline contemporary diagnostic algorithms for each of these disorders and provide an evidence-based approach to management.