Prevalence of thrombocytosis in critically ill patients and its association with symptomatic acute pulmonary embolism. A multicentre registry study

Examining the controversies in venous thromboembolism prophylaxis for vascular surgery patients: A critical review

BACKGROUND

Venous thromboembolism (VTE) is a significant concern in vascular surgery due to its potentially severe consequences. Effective prophylactic measures are essential to minimize the risks associated with VTE. However, considerable controversy remains regarding the optimal strategies for VTE prevention in patients undergoing vascular procedures.

METHODS

This review critically analyzes key clinical research, guidelines, and expert opinions to explore the advantages and limitations of various VTE prophylaxis approaches. The pharmacological and mechanical methods are explored, with a focus on balancing the risk of VTE against the potential for bleeding complications, particularly in high-risk patients.

RESULTS

The review addresses controversial issues such as the choice of anticoagulants, dosage, timing, and duration of prophylaxis. The lack of consensus in existing guidelines and the variability in clinical practice regarding VTE prevention in vascular surgery patients is highlighted. The role of patient-specific risk factors, including the use of intraoperative anticoagulation and bleeding risks, is also examined.

CONCLUSION

This review provides a comprehensive evaluation of VTE prophylaxis strategies in vascular surgery, emphasizing the need for individualized, evidence-based approaches. Clarifying these controversies is crucial for optimizing patient outcomes and minimizing both thrombotic and hemorrhagic complications.

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.

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.

Novel marker for predicting the severity and prognosis of acute pulmonary embolism: platelet-to-hemoglobin ratio

Background: We investigated the ability of the platelet-to-hemoglobin ratio (PHR) to predict mortality and disease severity in patients with acute pulmonary embolism (APE). Materials & methods: The severity of APE was classified as massive (high risk), submassive (intermediate risk) or nonmassive (low risk). PHR is defined as platelet count/hemoglobin count. Results: PHR was significantly higher in patients with massive APE, and this elevation showed a gradual increase from the nonmassive group to the massive group (p < 0.001). In-hospital and 1-month mortality were higher in patients with high PHR values. PHR was an independent risk factor for the development of massive APE (odds ratio: 1.014; 95% CI: 1.011-1.017; p = 0.009). Conclusion: PHR values predicted massive APE and were an independent predictor of mortality in APE.

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.

Prevention of Pulmonary and Venous Thromboembolism Post Coronary Artery Bypass Graft Surgery - Literature Review

Objective

The current review evaluates recent literature on the different aspects of prophylaxis in postoperative pulmonary and venous thromboembolism and their main risk factors.

Methods

The literature survey was carried out based on the PubMed data using the keywords “coronary artery bypass graft” and “venous thromboembolism” as components of the search field title.

Results

Studies reported several risk factors for postoperative thromboembolism including advanced age, postoperative immobilization, type of thromboprophylaxis, obesity, and location of the surgery.

Conclusion

According to the studies, tailored prophylaxis could be easily adapted to decrease the intensity and duration of postoperative thromboembolism in a patient with several disorders and comorbidities, especially in cardiovascular disease.

Reliability of Platelet Indices for Diagnosing Pulmonary Embolism; a Brief Report

Introduction:

Early diagnosis of pulmonary thromboembolism (PTE) is crucial in clinical medicine. Many para-clinical measurements are used to diagnose PTE.

Objective:

The present study was conducted to evaluate platelet indices in terms of diagnosing PTE.

Methods:

The present case-control study was conducted between May 2015 to July 2016 with 173 patients suspected of PTE in the emergency wards of Shahid Madani Hospital and Imam Reza Hospital affiliated to Tabriz University of Medical Sciences, Iran. The patients’ platelet indices were checked upon admission and they were evaluated in terms of diagnosing PTE. Platelet indices included mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PL-CR). PTE was diagnosed in 125 out of the 173 patients. Platelet indices were also compared between two groups.

Results:

No statistically significant differences were observed between the two groups in term of demographic variables (p>0.05). MPV was found to be 10.38±8.59 in the case group and 9.46±1.11 in the controls (p>0.05). PDW was also found to be 12.86±5.57 in the case group and 12.32±2.48 in the controls (p>0.05). Moreover, PL-CR was found to be 22.59±7.32 in the case group and 21.97±8.16 in the controls (p>0.05).

Conclusion:

According to the obtained results, platelet indices do not increase in PTE. They cannot be therefore used to diagnose PTE in suspected patients.

Predicting contrast-induced nephropathy after CT pulmonary angiography in the critically ill: a retrospective cohort study

Background

It is uncertain whether we can predict contrast-induced nephropathy (CIN) after CT pulmonary angiography (CTPA). This study compared the ability of a validated CIN prediction score with the Pulmonary Embolism Severity Index (PESI) in predicting CIN after CTPA.

Methods

This cohort study involved critically ill adult patients who required a CTPA to exclude acute pulmonary embolism (PE). Patients with end-stage renal failure requiring dialysis were excluded. CIN was defined as an elevation in plasma creatinine concentrations > 44.2μmol/l (or 0.5 mg/dl) within 48 h after CTPA.

Results

Of the 137 patients included, 77 (51%) were hypotensive, 54 (39%) required inotropic support, and 68 (50%) were mechanically ventilated prior to the CTPA. Acute PE was confirmed in 21 patients (15%) with 14 (10%) being bilateral. CIN occurred in 56 patients (41%) with 35 (26%) required dialysis subsequent to CTPA. The CIN prediction score had a good ability to discriminate between patients with and without developing CIN (Area under the receiver-operating-characteristic (AUROC) curve 0.864, 95% confidence interval [CI] 0.795–0.916) and requiring subsequent dialysis (AUROC 0.897, 95% CI 0.833–0.942) and was better than the PESI in predicting both outcomes (AUROC 0.731, 95% CI 0.649–0.804 and 0.775, 95% CI 0.696–0.842, respectively). A CIN risk score > 10 and 12 had an 82.1 and 85.7% sensitivity and 81.5 and 78.4% specificity to predict subsequent CIN and dialysis, respectively. The CIN prediction model tended to underestimate the observed risks of dialysis, but this was improved after recalibrating the slope and intercept of the original prediction equation.

Conclusions

The CIN prediction score had a good ability to discriminate between critically ill patients with and without developing CIN after CTPA. Used together for critically ill patients with suspected acute PE, the CIN prediction score and PESI may be useful to inform clinicians when the benefits of a CTPA scan will outweigh its potential harms.

Electronic supplementary material

The online version of this article (10.1186/s40560-018-0274-z) contains supplementary material, which is available to authorized users.

Detailed assessment of benefits and risks of retrievable inferior vena cava filters on patients with complicated injuries: the da Vinci multicentre randomised controlled trial study protocol

INTRODUCTION

Retrievable inferior vena cava (IVC) filters have been increasingly used in patients with major trauma who have contraindications to anticoagulant prophylaxis as a primary prophylactic measure against venous thromboembolism (VTE). The benefits, risks and cost-effectiveness of such strategy are uncertain.

METHODS AND ANALYSIS

Patients with major trauma, defined by an estimated Injury Severity Score >15, who have contraindications to anticoagulant VTE prophylaxis within 72 hours of hospitalisation to the study centre will be eligible for this randomised multicentre controlled trial. After obtaining consent from patients, or the persons responsible for the patients, study patients are randomly allocated to either control or IVC filter, within 72 hours of trauma admission, in a 1:1 ratio by permuted blocks stratified by study centre. The primary outcomes are (1) the composite endpoint of (A) pulmonary embolism (PE) as demonstrated by CT pulmonary angiography, high probability ventilation/perfusion scan, transoesophageal echocardiography (by showing clots within pulmonary arterial trunk), pulmonary angiography or postmortem examination during the same hospitalisation or 90-day after trauma whichever is earlier and (B) hospital mortality; and (2) the total cost of treatment including the costs of an IVC filter, total number of CT and ultrasound scans required, length of intensive care unit and hospital stay, procedures and drugs required to treat PE or complications related to the IVC filters. The study started in June 2015 and the final enrolment target is 240 patients. No interim analysis is planned; incidence of fatal PE is used as safety stopping rule for the trial.

ETHICS AND DISSEMINATION

Ethics approval was obtained in all four participating centres in Australia. Results of the main trial and each of the secondary endpoints will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ACTRN12614000963628; Pre-results.

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.

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.

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.

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.

Stratified meta-analysis of intermittent pneumatic compression of the lower limbs to prevent venous thromboembolism in hospitalized patients

BACKGROUND

Optimal thromboprophylaxis for patients at risk of bleeding remains uncertain. This meta-analysis assessed whether intermittent pneumatic compression (IPC) of the lower limbs was effective in reducing venous thromboembolism and whether combining pharmacological thromboprophylaxis with IPC would enhance its effectiveness.

METHODS AND RESULTS

Two reviewers searched MEDLINE, EMBASE, and the Cochrane controlled trial register (1966-February 2013) for randomized, controlled trials and assessed the outcomes and quality of the trials independently. Trials comparing IPC with pharmacological thromboprophylaxis, thromboembolic deterrent stockings, no prophylaxis, and a combination of IPC and pharmacological thromboprophylaxis were considered. Trials that used IPC <24 hours or compared different types of IPC were excluded. A total of 16 164 hospitalized patients from 70 trials met the inclusion criteria and were subjected to meta-analysis. IPC was more effective than no IPC prophylaxis in reducing deep vein thrombosis (7.3% versus 16.7%; absolute risk reduction, 9.4%; 95% confidence interval [CI], 7.9-10.9; relative risk, 0.43; 95% CI, 0.36-0.52; P<0.01; I(2)=34%) and pulmonary embolism (1.2% versus 2.8%; absolute risk reduction, 1.6%; 95% CI, 0.9-2.3; relative risk, 0.48; 95% CI, 0.33-0.69; P<0.01; I(2)=0%). IPC was also more effective than thromboembolic deterrent stockings in reducing deep vein thrombosis and appeared to be as effective as pharmacological thromboprophylaxis but with a reduced risk of bleeding (relative risk, 0.41; 95% CI, 0.25-0.65; P<0.01; I(2)=0%). Adding pharmacological thromboprophylaxis to IPC further reduced the risk of deep vein thrombosis (relative risk, 0.54; 95% CI, 0.32-0.91; P=0.02; I(2)=0%) compared with IPC alone.

CONCLUSIONS

IPC was effective in reducing venous thromboembolism, and combining pharmacological thromboprophylaxis with IPC was more effective than using IPC alone.