Sepsis-associated thrombocytopenia

Quantitative changes in platelet count in response to different pathogens: an analysis of patients with sepsis in both retrospective and prospective cohorts

BACKGROUND

Thrombocytopenia is commonly observed in patients with sepsis and is an independent risk factor for poor prognosis. However, the changes of platelet count caused by different pathogens can vary significantly. Our study aims to evaluate the quantitative changes in platelet count in response to various pathogens.

MATERIAL AND METHODS

We retrospectively analysed data of 3044 patients with sepsis from Medical Information Mart for Intensive Care (MIMIC, 2008-2019) database and prospectively collected data of 364 patients with sepsis from our local cohort of the Shandong Bloodstream Infection and Sepsis Collaboration Study (SBISC, 2020-2022). Propensity score matching (PSM) was employed to control for baseline differences in variables, except for the causative pathogen.

RESULTS

Multivariate logistic analyses of both original and PSM populations identified Candida, Escherichia, Klebsiella, and Serratia species posing a higher risk for thrombocytopenia compared to others. Restricted cubic spline (RCS) curves showed L- or U-shaped associations between platelet count and 28-mortality with various cut-off values among different pathogens: ranging from 96 × 109/L in Candida species - 190 × 109/L in Klebsiella species.

CONCLUSION

Our present findings indicate a pathogen-specific effect on platelet count, highlighting the importance of monitoring thrombocytopenia in patients infected with above microorganisms. Clinicians need to consider pathogen-specific thresholds when intervene on platelet count.

Differentiating Between Knee Septic Arthritis and Lyme Arthritis in Children: A Clinical Prediction Algorithm for a Geographically Diverse Population

BACKGROUND

Knee septic arthritis (SA) and Lyme arthritis (LA) often have similar presentations but bacterial SA necessitates urgent surgery. Predictive factors for differentiating SA and other infectious/inflammatory conditions have been published. Our purpose was to test these algorithms using a retrospective multicenter musculoskeletal infection database.

METHODS

Patients ≤18 years old with isolated knee SA or LA were identified. Diagnostic criteria for SA were synovial WBC count >50,000 cells/mm3, imaging with fluid aspiration suggestive of SA, or joint aspirate/tissue sample cultured positive for bacteria. Diagnostic criteria for LA was positive Lyme titer. Demographics, weightbearing status, admission vitals, and laboratory tests were collected. Predictive factors from Baldwin criteria for differentiating knee SA and LA, and Kocher criteria for differentiating hip SA and transient synovitis were tested.

RESULTS

One hundred fifty-five patients (119 SA and 36 LA) were analyzed. Patients with SA were younger (2.2 vs. 8.0 y), more nonweightbearing (74% vs. 33%), had a higher pulse (127 vs. 106), and higher WBC (12.4 vs. 10.2) (all P<0.001).Baldwin criteria (pain with joint motion, history of fever, CRP >40 mg/L, age <2 y) were tested. Pain with motion was not collected in our database. Of the remaining factors, the probability of SA was 63% with 0 and 92% with 3 factors (AUC 0.64). Kocher criteria (nonweightbearing, temperature >101.3°F, WBC >12.0, ESR >40) and CRP >20 mg/L were also tested. The probability of SA was 41% with 0 and 96% with all factors (AUC 0.69).Using our cohort data, regression analysis with backward stepwise elimination determined that age <4 years, nonweightbearing, admission WBC >13.0, platelets <325, and ESR >70 were predictive factors for SA. The probability of SA with 0 factors was 16%, 1 factor 52%, 2 factors 86%, 3 factors 97%, and 4 factors 100% (AUC 0.86).

CONCLUSIONS

Our model identified age <4 years, nonweightbearing, admission WBC >13.0, platelets <325, and ESR >70 as independent predictive factors for knee SA. The more factors present, the higher the likelihood of having SA versus LA.

LEVEL OF EVIDENCE

Diagnostic level III.

Delta Immature Platelet Fraction Is Associated With Mortality in Bacteremia Patients

OBJECTIVES

Immature platelet fraction (IPF) for differentiating bacteremia has been explored, whereas its prognostic correlation remains uncertain. This study aims to confirm the predictive capability of IPF for bacteremia and investigate its association with prognosis.

METHODS

Patients with complete blood count (CBC) on the blood culture day (D1) and the preceding day (D0) were retrospectively recruited and categorized into bacteremia and nonbacteremia groups. Immature platelet (IP) analysis, alongside CBC, was conducted. Delta IPF, defined by the absolute values of D1 minus D0 results was calculated. The ability to distinguish bacteremia from nonbacteremia patients, and the correlation with mortality were analyzed.

RESULTS

From February to December 2020, a total of 150 patients were enrolled, with 75 having bacteremia. The specificity for delta IPF ≥3.4% to predict bacteremia was 97.3% (95% confidence interval [CI]: 90.7-99.7). When delta IPF ≥3.4% combined with procalcitonin ≥0.5 (ng/mL), the sensitivity was 90.5% (95% CI: 69.6%-98.8%). Within the bacteremia group, delta IPF and the proportion of patients with delta IPF ≥1.5% were significantly higher in nonsurvival, while delta platelet levels did not. Furthermore, delta IPF ≥1.5% was independently associated with 30-day mortality (adjusted odds ratio: 3.88, 95% CI: 1.2%-11.4%; p = 0.020). The 30-day survival curve demonstrated a significant difference between patients with delta IPF ≥1.5% and those without (p < 0.001).

CONCLUSIONS

Delta IPF correlates with mortality in bacteremia patients. Our findings suggest IPF not only helps detect bacteremia but also predicts prognosis in the early stage.

Elevated platelet count is associated with decreased mortality from hemorrhagic stroke in hospital: a multi-center retrospective cohort study

This study aimed to investigate the relationship between platelet count (PC) and mortality in patients with hemorrhagic stroke (HS). The research reviewed data from 10,466 patients hospitalized in 208 hospitals in the United States from January 1, 2014, to December 31, 2015. Of these, 3262 HS patients were included in the primary analysis for those admitted to the intensive care unit (ICU). The average age of these patients was 67.05 years, with 52.79% being male. The median PC was (221.67 ± 73.78) × 109/L. Multivariate logistic regression analysis revealed that PC was a protective factor for mortality in HS patients (OR = 0.98, 95% CI 0.97-1.00, P < 0.05). Additionally, a non-linear association between PC and mortality in HS patients was found using a generalized additive model (GAM) and smooth curve fitting (penalty spline method). For the first time, a recursive algorithm identified the inflection point of platelet count as 194 × 109/L. On the left side of the inflection point, for every increase of 10 units in platelet count, the mortality rate of HS patients decreases by 10%. The study demonstrates a non-linear relationship between PC and the risk of mortality in HS patients. A platelet counts higher than the inflection point (194 × 109/L) may be a significant intervention to reduce mortality in HS patients.

Hematological adverse events associated with anti-MRSA agents: a real-world analysis based on FAERS

This study investigated the patterns of hematological adverse events related to daptomycin (DAP), tigecycline (TIG), vancomycin (VAN) and linezolid (LIN) in the FDA Adverse Event Reporting System (FAERS). Adverse event associations were analyzed through calculating reporting odds ratio (ROR), proportional reporting ratio (PRR), multiple gamma Poisson shrinkage (MGPS), and Bayesian confidence propagation neural network (BCPNN). A comprehensive descriptive analysis was also conducted considering factors such as age, gender, daily dose, cumulative dose, and time to onset. The leading hematologic adverse events were eosinophilia for daptomycin, coagulation abnormalities and thrombocytopenia for tigecycline, thrombocytopenia, neutropenia, and anemia for linezolid, and thrombocytopenia, eosinophilia, and neutropenia for vancomycin. Most of the affected patients were over 55 years old. Daily doses for the tigecycline and daptomycin groups exceeded the standard daily dose. The times to onset were 14.00 days for daptomycin (interquartile range [IQR], 4.00-21.00), 6.00 days for tigecycline (IQR, 2.00-9.00), 10.00 days for linezolid (IQR, 4.00-16.5), and 10.00 days for vancomycin (IQR,5.00-20.00). It is essential to intensify early monitoring and identification of these adverse events, especially in the context of off-label dosages and for elderly patients and individuals taking medication for over one week.

Platelet count predicts mortality in patients with sepsis: A retrospective observational study

Platelet count is a key component of sepsis severity score. However, the predictive value of the platelet count at admission for mortality in sepsis remains unclear. We designed a retrospective observational study of patients with sepsis admitted to our hospital from January 2017 to September 2021 to explore the predictive value of platelet count at admission for mortality. A total of 290 patients with sepsis were included in this study. Multivariate logistic regression analysis was used to evaluate the risk factors for mortality and construct a predictive model with statistically significant factors. Compared with survivors, nonsurvivors tended to be much older and had significantly higher acute physiology and chronic health evaluation II and sequential organ failure assessment scores (P < .001). The platelet count was significantly lower in the nonsurvivor group than in the survivor group (P < .001). Multivariate logistic regression analysis indicated that age (P = .003), platelet count (P < .001) and lactate level (P = .018) were independent risk factors for mortality in patients with sepsis. Finally, the area under the receiver operating characteristic curve of platelet count predicting mortality in sepsis was 0.763 (95% confidence interval, 0.709-0.817, P < .001), with a sensitivity of 55.6% and a specificity of 91.8%. In our study, platelet count at admission as a single biomarker showed good predictability for mortality in patients with sepsis.

Adrenal Abscesses: A Systematic Review of the Literature

Objective: To summarize the existing knowledge about adrenal gland abscesses, including etiology, clinical presentation, common laboratory and imaging findings, management and overall morbidity and mortality. Design: Systematic literature review. Methods: We performed a search in the PubMed database using search terms: 'abscess and adrenal glands', 'adrenalitis', 'infection and adrenal gland', 'adrenal abscess', 'adrenal infection' and 'infectious adrenalitis'. Articles from 2017 to 2022 were included. We found total of 116 articles, and after applying exclusion criteria, data from 73 articles was included in the final statistical analysis. Results: Of 84 patients included in this review, 68 were male (81%), with a mean age of 55 years (range: 29 to 85 years). Weight loss was the most frequent symptom reported in 58.3% patients, followed by fever in 49%. Mean duration of symptoms was 4.5 months. The most common laboratory findings were low cortisol (51.9%), elevated ACTH (43.2%), hyponatremia (88.2%) and anemia (83.3%). Adrenal cultures were positive in 86.4% cases, with Histoplasma capsulatum (37.3%) being the leading causative agent. Blood cultures were positive in 30% of patients. The majority of the adrenal infections occurred through secondary dissemination from other infectious foci and abscesses were more commonly bilateral (70%). A total of 46.4% of patients developed long-term adrenal insufficiency requiring treatment. Abscess drainage was performed in 7 patients (8.3%) and adrenalectomy was performed in 18 (21.4%) patients. The survival rate was 92.9%. Multivariate analysis showed that the only independent risk factor for mortality was thrombocytopenia (p = 0.048). Conclusion: Our review shows that adrenal abscesses are usually caused by fungal pathogens, and among these, Histoplasma capsulatum is the most common. The adrenal glands are usually involved in a bilateral fashion and become infected through dissemination from other primary sources of infection. Long-term adrenal insufficiency develops in 46% of patients, which is more common than what is observed in non-infectious etiology of adrenal gland disorders. Mortality is about 7%, and the presence of thrombocytopenia is associated with worse prognosis. Further prospective studies are needed to better characterize optimal testing and treatment duration in patients with this relatively rare but challenging disorder.

Myristica fragrans Extract Inhibits Platelet Desialylation and Activation to Ameliorate Sepsis-Associated Thrombocytopenia in a Murine CLP-Induced Sepsis Model

Sepsis, characterized by an uncontrolled host inflammatory response to infections, remains a leading cause of death in critically ill patients worldwide. Sepsis-associated thrombocytopenia (SAT), a common disease in patients with sepsis, is an indicator of disease severity. Therefore, alleviating SAT is an important aspect of sepsis treatment; however, platelet transfusion is the only available treatment strategy for SAT. The pathogenesis of SAT involves increased platelet desialylation and activation. In this study, we investigated the effects of Myristica fragrans ethanol extract (MF) on sepsis and SAT. Desialylation and activation of platelets treated with sialidase and adenosine diphosphate (platelet agonist) were assessed using flow cytometry. The extract inhibited platelet desialylation and activation via inhibiting bacterial sialidase activity in washed platelets. Moreover, MF improved survival and reduced organ damage and inflammation in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. It also prevented platelet desialylation and activation via inhibiting circulating sialidase activity, while maintaining platelet count. Inhibition of platelet desialylation reduces hepatic Ashwell-Morell receptor-mediated platelet clearance, thereby reducing hepatic JAK2/STAT3 phosphorylation and thrombopoietin mRNA expression. This study lays a foundation for the development of plant-derived therapeutics for sepsis and SAT and provides insights into sialidase-inhibition-based sepsis treatment strategies.

Machine learning models for prediction of invasion Klebsiella pneumoniae liver abscess syndrome in diabetes mellitus: a singled centered retrospective study

OBJECTIVE

This study aimed to develop and validate a machine learning algorithm-based model for predicting invasive Klebsiella pneumoniae liver abscess syndrome(IKPLAS) in diabetes mellitus and compare the performance of different models.

METHODS

The clinical signs and data on the admission of 213 diabetic patients with Klebsiella pneumoniae liver abscesses were collected as variables. The optimal feature variables were screened out, and then Artificial Neural Network, Support Vector Machine, Logistic Regression, Random Forest, K-Nearest Neighbor, Decision Tree, and XGBoost models were established. Finally, the model's prediction performance was evaluated by the ROC curve, sensitivity (recall), specificity, accuracy, precision, F1-score, Average Precision, calibration curve, and DCA curve.

RESULTS

Four features of hemoglobin, platelet, D-dimer, and SOFA score were screened by the recursive elimination method, and seven prediction models were established based on these variables. The AUC (0.969), F1-Score(0.737), Sensitivity(0.875) and AP(0.890) of the SVM model were the highest among the seven models. The KNN model showed the highest specificity (1.000). Except that the XGB and DT models over-estimates the occurrence of IKPLAS risk, the other models' calibration curves are a good fit with the actual observed results. Decision Curve Analysis showed that when the risk threshold was between 0.4 and 0.8, the net rate of intervention of the SVM model was significantly higher than that of other models. In the feature importance ranking, the SOFA score impacted the model significantly.

CONCLUSION

An effective prediction model of invasion Klebsiella pneumoniae liver abscess syndrome in diabetes mellitus could be established by a machine learning algorithm, which had potential application value.

Reduced numbers of regulatory T cells in chronic heart failure seems not to be restored by cardiac resynchronization therapy

BACKGROUND

T cells have been implicated in the development and progression of inflammatory processes in chronic heart failure (CHF). Cardiac resynchronization therapy (CRT) has beneficial effects on symptoms and cardiac remodeling in CHF. However, its impact on the inflammatory immune response remains controversial. We aimed to study the impact of CRT on T cells in heart failure (HF) patients.

METHODS

Thirty-nine HF patients were evaluated before CRT (T0) and six months later (T6). Quantification of T cells, their subsets, and their functional characterization, after in vitro stimulation, were evaluated by flow cytometry.

RESULTS

T regulatory (Treg) cells were decreased in CHF patients (healthy group (HG): 1.08 ± 0.50 versus (heart failure patients (HFP)-T0: 0.69 ± 0.40, P = 0.022) and remaining diminished after CRT (HFP-T6: 0.61 ± 0.29, P = 0.003). Responders (R) to CRT presented a higher frequency of T cytotoxic (Tc) cells producing IL-2 at T0 compared with non-responders (NR) (R: 36.52 ± 12.55 versus NR: 24.71 ± 11.66, P = 0.006). After CRT, HF patients presented a higher percentage of Tc cells expressing TNF-α and IFN-γ (HG: 44.50 ± 16.62 versus R: 61.47 ± 20.54, P = 0.014; and HG: 40.62 ± 15.36 versus R: 52.39 ± 18.66, P = 0.049, respectively).

CONCLUSION

The dynamic of different functional T cell subpopulations is significantly altered in CHF, which results in an exacerbated pro-inflammatory response. Even after CRT, it seems that the inflammatory condition underlying CHF continues to evolve with the progression of the disease. This could be due, at least in part, to the inability to restore Treg cells levels.

TRIAL REGISTRATION

Observational and prospective study with no trial registration.

Effect of antiplatelet agents on Escherichia coli sepsis mechanisms: A review

Despite ever-increasing improvements in the prognosis of sepsis, this condition remains a frequent cause of hospitalization and mortality in Western countries. Sepsis exposes the patient to multiple complications, including thrombotic complications, due to the ability of circulating bacteria to activate platelets. One of the bacteria most frequently implicated in sepsis, Escherichia coli, a Gram-negative bacillus, has been described as being capable of inducing platelet activation during sepsis. However, to date, the mechanisms involved in this activation have not been clearly established, due to their multiple characteristics. Many signaling pathways are thought to be involved. At the same time, reports on the use of antiplatelet agents in sepsis to reduce platelet activation have been published, with variable results. To date, their use in sepsis remains controversial. The aim of this review is to summarize the currently available knowledge on the mechanisms of platelet activation secondary to Escherichia coli sepsis, as well as to provide an update on the effects of antiplatelet agents in these pathological circumstances.

How I use platelet transfusions

Platelet transfusions are commonly administered for the prevention or treatment of bleeding in patients with acquired thrombocytopenia across a range of clinical contexts. Recent data, including randomized trials, have highlighted uncertainties in the risk-benefit balance of this therapy, which is the subject of this review. Hemovigilance systems report that platelets are the most frequently implicated component in transfusion reactions. There is considerable variation in platelet count increment after platelet transfusion, and limited evidence of efficacy for clinical outcomes, including prevention of bleeding. Bleeding events commonly occur despite the different policies for platelet transfusion prophylaxis. The underlying mechanisms of harm reported in randomized trials may be related to the role of platelets beyond hemostasis, including mediating inflammation. Research supports the implementation of a restrictive platelet transfusion policy. Research is needed to better understand the impact of platelet donation characteristics on outcomes, and to determine the optimal thresholds for platelet transfusion before invasive procedures or major surgery (eg, laparotomy). Platelet transfusion policies should move toward a risk-adapted approach that does not focus solely on platelet count.

Complete Blood Count and Myocardial Markers Combination with Sequential Organ Failure Assessment Score Can Effectively Predict the Mortality in Sepsis: A Derivation and Validation Study

Purpose

The purpose of our study was to explore the prognostic value of complete blood count and myocardial markers combination with Sequential Organ Failure Assessment (SOFA) score in predicting the 28-day mortality among sepsis patients.

Patients and methods

A retrospective observational cohort study was performed. Three hundred and nineteen sepsis patients who were hospitalized at the Second Affiliated Hospital of Chongqing Medical University, China, from January 2019 to September 2021 were included. The clinical and laboratory data, the Acute Physiological and Chronic Health Evaluation II (APACHE II) score and SOFA score at the time of the initial sepsis diagnosis were collected, and the predictive values of the single and combination variables for 28-day mortality were compared.

Results

The derivation cohort consisted of 221 patients and included 59 (26.7%) died. The area under the curve (AUC) [95% confidence interval (CI)] of RDW and cTnT were 0.735 (0.663–0.807) and 0.753 (0.678–0.827) for mortality, and the cut-off value were 14.05% and 0.039 ng/mL, respectively. The combination of RDW, cTnT and the SOFA score showed a better performance for the prediction of mortality, and the AUC was significantly higher than that of the SOFA score (0.791 vs 0.726, DeLong test: P=0.032). Multivariate Cox analysis identified that the combination of RDW, cTnT and the SOFA score (HR=6.133, P=0.004) and APACHE II score (HR=1.093, P<0.001) were independent detrimental factors for 28-day mortality. The validation cohort consisted of 98 patients and included 23 (23.5%) died. Similarly, the AUC of the RDW, cTnT and the SOFA score combination is significantly higher than that of the SOFA score (0.821 vs 0.739, DeLong test: P=0.035).

Conclusion

RDW and cTnT showed good performance in predicting 28-day mortality rates among patients with sepsis. Combined RDW and cTnT with the SOFA score can significantly improve the predictive value of SOFA score for the prognosis of sepsis.

Platelets in pediatric and neonatal sepsis: novel mediators of the inflammatory cascade

Sepsis, a dysregulated host response to infection, has been difficult to accurately define in children. Despite a higher incidence, especially in neonates, a non-specific clinical presentation alongside a lack of verified biomarkers has prevented a common understanding of this condition. Platelets, traditionally regarded as mediators of haemostasis and thrombosis, are increasingly associated with functions in the immune system with involvement across the spectrum of innate and adaptive immunity. The large number of circulating platelets (approx. 150,000 cells per microlitre) mean they outnumber traditional immune cells and are often the first to encounter a pathogen at a site of injury. There are also well-described physiological differences between platelets in children and adults. The purpose of this review is to place into context the platelet and its role in immunology and examine the evidence where available for its role as an immune cell in childhood sepsis. It will examine how the platelet interacts with both humoral and cellular components of the immune system and finally discuss the role the platelet proteome, releasate and extracellular vesicles may play in childhood sepsis. This review also examines how platelet transfusions may interfere with the complex relationships between immune cells in infection. IMPACT: Platelets are increasingly being recognised as important "first responders" to immune threats. Differences in adult and paediatric platelets may contribute to differing immune response to infections. Adult platelet transfusions may affect infant immune responses to inflammatory/infectious stimuli.

Relative platelet reductions provide better pathophysiologic signatures of coagulopathies in sepsis

In sepsis-associated coagulopathies and disseminated intravascular coagulation, relative platelet reductions may reflect coagulopathy severity. However, limited evidence supports their clinical significance and most sepsis-associated coagulopathy criteria focus on the absolute platelet counts. To estimate the impact of relative platelet reductions and absolute platelet counts on sepsis outcomes. A multicenter retrospective observational study was performed using the eICU Collaborative Research Database, comprising 335 intensive care units (ICUs) in the United States. Patients with sepsis and an ICU stay > 2 days were included. Estimated effects of relative platelet reductions and absolute platelet counts on mortality and coagulopathy-related complications were evaluated. Overall, 26,176 patients were included. Multivariate mixed-effect logistic regression analysis revealed marked in-hospital mortality risk with larger platelet reductions between days one and two, independent from the resultant absolute platelet counts. The adjusted odds ratio (OR) [95% confidence intervals (CI)] for in-hospital mortality was 1.28[1.23–1.32], 1.86[1.75–1.97], 2.99[2.66–3.36], and 6.05[4.40–8.31] for 20–40%, 40–60%, 60–80%, and > 80% reductions, respectively, when compared with a < 20% decrease in platelets (P < 0.001 for each). In the multivariate logistic regression analysis, platelet reductions ≥ 11% and platelet counts ≤ 100,000/μL on day 2 were associated with high coagulopathy-related complications (OR [95%CI], 2.03 and 1.18; P < 0.001 and P < 0.001), while only platelet reduction was associated with thromboembolic complications (OR [95%CI], 1.43 [1.03–1.98], P < 0.001). The magnitude of platelet reductions represent mortality risk and provides a better signature of coagulopathies in sepsis; therefore, it is a plausible criterion for sepsis-associated coagulopathies.

Research Advances in the Subtype of Sepsis-Associated Thrombocytopenia

The incidence and mortality of sepsis in the intensive care unit (ICU) are extremely high. Thrombocytopenia, one of the most common laboratory abnormalities, is correlated with prognosis in sepsis. The pathophysiology of sepsis-associated thrombocytopenia (SAT) remains unclear and may be associated with several factors such as platelet activation due to vascular injury and pathogen, suppression of bone marrow, platelet-targeted antibodies and desialylation. This review summarized all these possible mechanisms in the 3 subtypes of SAT: increased platelet consumption, reduced platelet production and increased platelet destruction. Based on the clinically available platelet parameters, the evidence for identifying SAT subtypes and the recent progress in treatments according to these subtypes are proposed to provide new prospects for the management of SAT.

Coagulopathy and sepsis: Pathophysiology, clinical manifestations and treatment

Sepsis is a complex syndrome with a high incidence, increasing by 8.7% annually over the last 20 years. Coagulopathy is a leading factor associated with mortality in patients with sepsis and range from slight thrombocytopenia to fatal disorders, such as disseminated intravascular coagulation (DIC). Platelet reactivity increases during sepsis but prospective trials of antiplatelet therapy during sepsis have been disappointing. Thrombocytopenia is a known predictor of worse prognosis during sepsis. The mechanisms underlying thrombocytopenia in sepsis have yet to be fully understood but likely involves decreased platelet production, platelet sequestration and increased consumption. DIC is an acquired thrombohemorrhagic syndrome, resulting in intravascular fibrin formation, microangiopathic thrombosis, and subsequent depletion of coagulation factors and platelets. DIC can be resolved with treatment of the underlying disorder, which is considered the cornerstone in the management of this syndrome. This review presents the current knowledge on the pathophysiology, diagnosis, and treatment of sepsis-associated coagulopathies.

Hypercoagulability in Septic Shock Patients With Thrombocytopenia

BACKGROUND

Despite thrombocytopenia, patients with sepsis often experience hypercoagulability. However, limited information is available on the prevalence and effect of hypercoagulability in patients with sepsis-induced thrombocytopenia. Hence, we evaluated the prevalence of hypercoagulability and the association between hypercoagulability and clinical outcomes in septic shock patients with thrombocytopenia.

METHODS

Thromboelastography (TEG) was performed prospectively in 1294 patients with septic shock at the emergency department (ED) between January 2016 and December 2019. After excluding 405 patients who did not require resuscitation, refused enrollment, or developed septic shock after ED presentation, 889 patients were included. We defined thrombocytopenia as an admission platelet count lower than 150,000/µl according to SOFA score. We defined hypocoagulability and hypercoagulability as coagulation index (CI)< -3 and >3 on TEG, respectively.

RESULTS

Of the 889 septic shock patients (mean age 65.6 ± 12.7 years, 58.6% male), 473 (53.2%) had thrombocytopenia. Eighty-five (18.0%) patients showed hypercoagulable TEG and73 (15.4%) patients showed hypocoagulable TEG. The hypercoagulable TEG group had a significantly higher fibrinogen level and a lower 28-day mortality rate than the normal and hypocoagulable TEG groups (518 vs. 347 and 315 mg/dL; 7.1% vs. 21.1% and 36.8%, P < 0.01, respectively). In multivariate analysis, hypercoagulable TEG was associated with a decreased mortality rate (odds ratio: 0.395; 95% confidence interval, 0.162-0.965).

CONCLUSIONS

In septic shock patients with thrombocytopenia, hypercoagulability was not uncommon. TEG can quickly distinguish the hypercoagulability and hypocoagulability states and serve as a valuable tool for evaluating the degree and risk in septic shock patients with thrombocytopenia.

The lipid biology of sepsis

Sepsis, defined as the dysregulated immune response to an infection leading to organ dysfunction, is one of the leading causes of mortality around the globe. Despite the significant progress in delineating the underlying mechanisms of sepsis pathogenesis, there are currently no effective treatments or specific diagnostic biomarkers in the clinical setting. The perturbation of cell signaling mechanisms, inadequate inflammation resolution, and energy imbalance, all of which are altered during sepsis, are also known to lead to defective lipid metabolism. The use of lipids as biomarkers with high specificity and sensitivity may aid in early diagnosis and guide clinical decision making. In addition, identifying the link between specific lipid signatures and their role in sepsis pathology may lead to novel therapeutics. In this review, we discuss the recent evidence on dysregulated lipid metabolism both in experimental and human sepsis focused on bioactive lipids, fatty acids, and cholesterol as well as the enzymes regulating their levels during sepsis. We highlight not only their potential roles in sepsis pathogenesis but also the possibility of using these respective lipid compounds as diagnostic and prognostic biomarkers of sepsis.

Cytokine Adsorption in Severe Acute Respiratory Failure Requiring Veno-Venous Extracorporeal Membrane Oxygenation

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) is a last resort treatment option for patients with acute respiratory failure (acute respiratory distress syndrome [ARDS]). Cytokine adsorption has been incorporated in the management of some of these patients on an individual basis to control the imbalance of danger-associated molecular patterns and proinflammatory cytokines. However, little is known about the combination of V-V ECMO and cytokine adsorption as earlier reports contained mixed patient cohorts in terms of disease and mode of ECMO, veno-venous and veno-arterial. We here report single-center registry data of nine all-comers with severe ARDS treated with V-V ECMO and cytokine adsorption using the CytoSorb adsorber compared with a control group of nine propensity score matched patients undergoing V-V ECMO support without cytokine adsorption. Even though Respiratory ECMO Survival Prediction and PRedicting dEath for SEvere ARDS on V-V ECMO scores predicted a higher mortality in the cytokine adsorption group, mortality was numerically reduced in the patients undergoing V-V ECMO and cytokine removal compared with V-V ECMO alone. The need for fluid resuscitation and vasopressor support as well as lactate levels dropped significantly in the cytokine adsorption group within 72 hours, whereas vasopressor need and lactate levels did not decrease significantly in the control group. Therefore, our data suggest that cytokine adsorption might be beneficial in patients with severe ARDS requiring V-V ECMO support.

Thrombocytopenia Secondary to Herpes Simplex Virus-2 Infection Successfully Treated by Acyclovir

Thrombocytopenia is a common clinical condition associated with a wide variety of clinical conditions including infections, malignancy, medications, liver disorder, and autoimmune conditions, etc. The association between thrombocytopenia and herpes simplex virus (HSV) is reported only once in a case report dating back to 1978. We report a case of a 66-year-old female with generalized weakness, mechanical fall, genital ulcerations, and breast fold and genital area skin redness, warmth, and mild tenderness. Initial labs showed mild leukocytosis, normal platelet count, mild lactic acidosis, and urine analysis suggestive of urinary tract infection. The patient was started on broad-spectrum antibiotics. During the course of hospitalization, the patient developed severe thrombocytopenia with platelet counts dropping less than 40000/μL (normal range: 150,000-450,000/μL), and genital pain and ulceration worsened. The genital swab was sent which came back positive for the HSV-2 virus. Soon after the start of acyclovir for HSV-2 infection, the genital pain and ulceration improved and platelet counts gradually increased to 157,000/μL. Other causes of thrombocytopenia such as sepsis, heparin-induced thrombocytopenia, consumptive coagulopathy, medication-induced thrombocytopenia, immune thrombocytopenia, and thrombotic thrombocytopenic purpura were ruled out.

The role of endothelial shear stress on haemodynamics, inflammation, coagulation and glycocalyx during sepsis

Sepsis is a multifactorial syndrome primarily determined by the host response to an invading pathogen. It is common, with over 48 million cases worldwide in 2017, and often lethal. The sequence of events in sepsis begins with the damage of endothelium within the microvasculature, as a consequence of the inflammatory and coagulopathic responses to the pathogen that can progress to multiple organ failure and death. Most therapeutic interventions target the inflammation and coagulation pathways that act as an auto-amplified vicious cycle, which, if unchecked can be fatal. Normal blood flow and shear stress acting on a healthy endothelium and intact glycocalyx have anti-inflammatory, anticoagulant and self-repairing effects. During early stages of sepsis, the vascular endothelium and its glycocalyx become dysfunctional, yet they are essential components of resuscitation and recovery from sepsis. The effects of shear forces on sepsis-induced endothelial dysfunction, including inflammation, coagulation, complement activation and microcirculatory breakdown are reviewed. It is suggested that early therapeutic strategies should prioritize on the restoration of shear forces and endothelial function and on the preservation of the endothelial-glycocalyx barrier.

Safety of photosynthetic Synechococcus elongatus for in vivo cyanobacteria-mammalian symbiotic therapeutics

The cyanobacterium Synechococcus elongatus (SE) has been shown to rescue ischaemic heart muscle after myocardial infarction by photosynthetic oxygen production. Here, we investigated SE toxicity and hypothesized that systemic SE exposure does not elicit a significant immune response in rats. Wistar rats intravenously received SE (n = 12), sterile saline (n = 12) or E. coli lipopolysaccharide (LPS, n = 4), and a subset (8 SE, 8 saline) received a repeat injection 4 weeks later. At baseline, 4 h, 24 h, 48 h, 8 days and 4 weeks after injection, clinical assessments, blood cultures, blood counts, lymphocyte phenotypes, liver function tests, proinflammatory cytokines and immunoglobulins were assessed. Across all metrics, SE rats responded comparably to saline controls, displaying no clinically significant immune response. As expected, LPS rats exhibited severe immunological responses. Systemic SE administration does not induce sepsis or toxicity in rats, thereby supporting the safety of cyanobacteria-mammalian symbiotic therapeutics using this organism.

Efficacy and Safety of Recombinant Human Thrombopoietin on Sepsis Patients With Thrombocytopenia: A Systematic Review and Meta-Analysis

Background

The efficacy and safety of the administration of recombinant human thrombopoietin (rhTPO) in sepsis patients with thrombocytopenia were still inconclusive.

Objectives

To investigate whether rhTPO is a benefit for sepsis patients with thrombocytopenia.

Methods

PubMed, Cochrane library, Embase, China National Knowledge Infrastructure, and Wanfang Database were electronically searched to the randomized controlled trials (RCTs) from inception to March 4, 2020. The primary outcome was the level of platelet (PLT) on the 7^th day of treatment, and secondary outcomes were 28-d mortality, the level of coagulation indicators, hepatic and renal function indicators, blood transfusion, and length of intensive care unit (ICU) stay.

Results

Ten RCTs involving 681 patients were included. For compared with conventional antibiotic therapy, rhTPO could significantly increase platelet counts (PCs) [standardized mean difference (SMD), 2.61; 95% confidence interval (CI), 1.28-3.94; P < 0.001], decreased 28-d mortality [relative risk (RR), 0.66; 95%CI, 0.46-0.97; P=0.03], transfusion volume of blood products and length of ICU stay. Additionally, for compared with conventional antibiotic therapy combined with intravenous immunoglobulin, the pooled results shown that rhTPO also associated with an improvement of PCs on 7^th of treatment (SMD, 0.86; 95%CI, 0.54-1.17; P < 0.001), and a reduced transfusion volume of blood products. However, there were no differences in 28-d mortality and the length of ICU stay.

Conclusions

Current evidence shown that rhTPO could increase PCs on 7^th day of treatment and reduce the transfusion volume of blood products in sepsis-related thrombocytopenia during hospitalization. The conclusions are needed to be verified indeed by more multicenter RCTs due to the limitation of the included studies.

A Modified Simple Scoring System Using the Red Blood Cell Distribution Width, Delta Neutrophil Index, and Mean Platelet Volume-to-Platelet Count to Predict 28-Day Mortality in Patients With Sepsis

BACKGROUND

Recently, a new scoring system was developed that uses the red blood cell distribution width (RDW), delta neutrophil index (DNI), and platelet count (PC) to predict mortality in patients with sepsis. We investigated whether a modified simple scoring system based on the RDW, DNI, and mean platelet volume-to-PC (MPV/PC) ratio could predict the mortality of patients with sepsis, and compared it to the previous scoring system.

METHODS

We conducted a retrospective cohort study of 264 adults who had been treated for sepsis in an emergency department between January 2016 and February 2019. Each patient was rated on a scale of 0 to 3 according to the modified scoring system. Point values were assigned based on RDW > 14.5%, DNI > 5.0%, and MPV/PC ratio >10.1.

RESULTS

The 28-day mortality rate was 14.4%. Those who died had higher scores than those who survived (mean: 1.55 ± 0.92 vs 0.93 ± 0.78, P < .001). The area under the curve for the new scoring system was higher than that of the previous scoring system (0.685 vs 0.645).

CONCLUSION

The modified scoring system was a good predictor of the 28-day mortality and was more useful than the previous scoring system for predicting mortality in patients with sepsis.

A Champion of Host Defense: A Generic Large-Scale Cause for Platelet Dysfunction and Depletion in Infection

Thrombocytopenia is commonly associated with sepsis and infections, which in turn are characterized by a profound immune reaction to the invading pathogen. Platelets are one of the cellular entities that exert considerable immune, antibacterial, and antiviral actions, and are therefore active participants in the host response. Platelets are sensitive to surrounding inflammatory stimuli and contribute to the immune response by multiple mechanisms, including endowing the endothelium with a proinflammatory phenotype, enhancing and amplifying leukocyte recruitment and inflammation, promoting the effector functions of immune cells, and ensuring an optimal adaptive immune response. During infection, pathogens and their products influence the platelet response and can even be toxic. However, platelets are able to sense and engage bacteria and viruses to assist in their removal and destruction. Platelets greatly contribute to host defense by multiple mechanisms, including forming immune complexes and aggregates, shedding their granular content, and internalizing pathogens and subsequently being marked for removal. These processes, and the nature of platelet function in general, cause the platelet to be irreversibly consumed in the execution of its duty. An exaggerated systemic inflammatory response to infection can drive platelet dysfunction, where platelets are inappropriately activated and face immunological destruction. While thrombocytopenia may arise by condition-specific mechanisms that cause an imbalance between platelet production and removal, this review evaluates a generic large-scale mechanism for platelet depletion as a repercussion of its involvement at the nexus of responses to infection.

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

Thrombocytopenia is a common complication of critical care patients. The rates of bleeding events and mortality are also significantly increased in critical care patients with thrombocytopenia. Therefore, the Critical Care Medicine Committee of Chinese People's Liberation Army (PLA) worked with Chinese Society of Laboratory Medicine, Chinese Medical Association to develop this consensus to provide guidance for clinical practice. The consensus includes five sections and 27 items: the definition of thrombocytopenia, etiology and pathophysiology, diagnosis and differential diagnosis, treatment and prevention.

Reticulated platelets – clinical application and future perspectives

Reticulated platelets are immature platelets freshly released from the bone marrow into the circulation and contain vestigial amounts of ribonucleic acid. Thus, they can serve as an indicator for the activity of thrombopoiesis. Despite the current lack of a standardized reference method, two types of hematology analyzers have incorporated a fully automated measurement of reticulated platelets. The “immature platelet fraction” (IPF; Sysmex XE-/XN-series) has some clinical utility in the differential diagnosis of thrombocytopenia. This is less clear for “reticulated platelets” (retPLT; Abbott CELL-DYN Sapphire/Alinity HQ). The usefulness of these parameters in the prediction of platelet recovery after chemotherapy or stem cell transplantation and as a decision aid for platelet transfusions has not been unequivocally confirmed. Recent findings have shown an association of reticulated platelets with an adverse risk in patients with coronary artery disease and stroke as well as resistance to anti-platelet therapy. Furthermore, a role of reticulated platelets for the prediction of sepsis was indicated. However, validation in larger prospective trials is necessary to establish the clinical benefit of reticulated platelets in these conditions. This review gives an overview of the available analytical methods and summarizes the current knowledge regarding the clinical application of reticulated platelets.

Thrombocytopenia in the Intensive Care Unit

The evaluation and management of thrombocytopenia is a daily challenge for clinicians in the intensive care unit (ICU). Thrombocytopenia is incredibly common, present in upwards of 60% of ICU patients. Additionally, thrombocytopenia in the critically ill is rarely caused by a single etiology. Several causes of thrombocytopenia in the ICU including heparin-induced thrombocytopenia (HIT) and thrombotic thrombocytopenic purpura demand urgent recognition and intervention. This chapter provides a general overview of thrombocytopenia in the ICU and highlights important diagnostic and management considerations for some of the most common etiologies.

IL-18 and IL-35 in the serum of patients with sepsis thrombocytopenia and the clinical significance

Expression levels of interleukin-18 (IL-18) and IL-35 in the serum of patients with sepsis and without thrombocytopenia and patients with sepsis thrombocytopenia (TCP) were detected to preliminarily investigate their clinical significance. One hundred and sixty-six patients admitted to Jinan Central Hospital Affiliated to Shandong University from July 2013 to September 2015 were retrospectively analysed. There were 96 patients with sepsis without thrombocytopenia in the sepsis group, and 70 patients with sepsis TCP in the sepsis TCP group. In the same period, 80 healthy subjects were selected as the control group. Fluorescent quantitative PCR was used for the detection the expression of mRNA levels of IL-18 and IL-35, and Enzyme-linked immunosorbent assay for the detection of the protein concentrations of IL-18 and IL-35 in the serum of peripheral blood. The correlation between IL-18, IL-35 and platelets was analyzed. There were significant differences in albumin, creatinine, total bilirubin and platelet count between the sepsis group and the sepsis TCP group (P<0.05); the expression levels of mRNA of IL-18 and IL-35 in a karyocyte in peripheral blood in the sepsis group and the sepsis TCP group were higher than those in the control group (P<0.05); the expression of mRNA of IL-18 and IL-35 in the sepsis TCP group was higher than those in the sepsis group (P<0.05). The concentration of IL-18 and IL-35 in the sepsis TCP group was higher than in the sepsis group (P<0.05); IL-18 and IL-35 were negatively correlated with platelets (r=−0.8749, −0.6228, P<0.001). There was a significant positive correlation between serum IL-18 and IL-35 in the control group, sepsis group, and sepsis TCP group (r=0.5124, 0.5718, 0.5511, P<0.001). IL-18 and IL-35 were negatively correlated with the reduced degree of platelets in patients with sepsis and are likely to play an important role in the pathogenetic process of sepsis TCP.

Macrophage Depletion Mitigates Platelet Aggregate Formation in Splenic Marginal Zone and Alleviates LPS-Associated Thrombocytopenia in Rats

Sepsis is often accompanied with thrombocytopenia partly due to platelet sequestration in the lung and liver. The spleen can store up to one-third of circulating platelets and can also significantly affect platelet transfusion outcomes by accumulating platelets. However, in sepsis, it is not clear whether there are platelet changes in the spleen which could contribute to sepsis-associated thrombocytopenia and also influence platelet transfusion outcomes. By using confocal microscopy, we examined endogenous rat platelets and infused human platelets in the spleen of severe combined immune deficient Rag2 KO rats which were injected intraperitoneally with lipopolysaccharide (LPS). LPS-injected Rag2 KO rats developed sepsis as indicated by increased TNFa, IL-6, IL-1b, and IL-10 levels and thrombocytopenia. Large platelet aggregates were observed in the spleen with majority located in the marginal zone and closely associated with CD169+ macrophages. Depletion of macrophages by clodrosome resulted in reduction of LPS-induced cytokine generation and alleviated LPS-induced thrombocytopenia. Macrophage depletion also remarkedly diminished large platelet aggregate formation in the splenic marginal zone but had less effect on those in red pulp. Infusion of human platelets into LPS-injected rats failed to raise platelet counts in the peripheral blood. In LPS-injected rat spleen, human platelets interacted with aggregated rat platelets in the marginal zone. In contrast, human platelets infused into control rats were located outside of splenic marginal zone. This study provides morphological evidence of platelet aggregates in the splenic marginal zone in sepsis which can interact with infused platelets and thus can contribute to platelet infusion refractoriness in sepsis. It indicates that macrophages play an important role in LPS-associated thrombocytopenia. It also suggests that CD169+ macrophages support platelet aggregate formation in the splenic marginal zone.

Platelets and Intravascular Immunity: Guardians of the Vascular Space During Bloodstream Infections and Sepsis

Despite their humble origins as anuclear fragments of megakaryocytes, platelets have emerged as versatile mediators of thrombosis and immunity. The diverse spectrum of platelet functions are on full display during the host response to severe infection and sepsis, with platelets taking center-stage in the intravascular immune response to blood-borne pathogens. Platelets are endowed with a comprehensive armamentarium of pathogen detection systems that enable them to function as sentinels in the bloodstream for rapid identification of microbial invasion. Through both autonomous anti-microbial effector functions and collaborations with other innate immune cells, platelets orchestrate a complex intravascular immune defense system that protects against bacterial dissemination. As with any powerful immune defense system, dysregulation of platelet-mediated intravascular immunity can lead to profound collateral damage to host cells and tissues, resulting in sepsis-associated organ dysfunction. In this article, the cellular and molecular contributions of platelets to intravascular immune defenses in sepsis will be reviewed, including the roles of platelets in surveillance of the microcirculation and elicitation of protective anti-bacterial responses. Mechanisms of platelet-mediated thromboinflammatory organ dysfunction will be explored, with linkages to clinical biomarkers of platelet homeostasis that aid in the diagnosis and prognostication of human sepsis. Lastly, we discuss novel therapeutic opportunities that take advantage of our evolving understanding of platelets and intravascular immunity in severe infection.

New Insights Into the Differentiation of Megakaryocytes From Hematopoietic Progenitors

Megakaryocytes are hematopoietic cells, which are responsible for the production of blood platelets. The traditional view of megakaryopoiesis describes the cellular journey from hematopoietic stem cells, through a hierarchical series of progenitor cells, ultimately to a mature megakaryocyte. Once mature, the megakaryocyte then undergoes a terminal maturation process involving multiple rounds of endomitosis and cytoplasmic restructuring to allow platelet formation. However, recent studies have begun to redefine this hierarchy and shed new light on alternative routes by which hematopoietic stem cells are differentiated into megakaryocytes. In particular, the origin of megakaryocytes, including the existence and hierarchy of megakaryocyte progenitors, has been redefined, as new studies are suggesting that hematopoietic stem cells originate as megakaryocyte-primed and can bypass traditional lineage checkpoints. Overall, it is becoming evident that megakaryopoiesis does not only occur as a stepwise process, but is dynamic and adaptive to biological needs. In this review, we will reexamine the canonical dogmas of megakaryopoiesis and provide an updated framework for interpreting the roles of traditional pathways in the context of new megakaryocyte biology. Visual Overview- An online visual overview is available for this article.

Evaluation of a novel prognostic score based on thrombosis and inflammation in patients with sepsis: a retrospective cohort study

BACKGROUND

Inflammation and thrombosis are involved in the development and progression of sepsis. A novel thrombo-inflammatory prognostic score (TIPS), based on both an inflammatory and a thrombus biomarker, was assessed for its ability to predict adverse outcomes of sepsis patients in the emergency department (ED).

METHODS

This was a retrospective cohort study of sepsis patients. TIPS (range: 0-2) was predictive of adverse outcomes. Multivariable logistic regression analyses were performed to investigate the associations between TIPS and 28-day adverse outcomes. The study end points were mortality, mechanical ventilation (MV), consciousness disorder (CD) and admission to the intensive care unit (AICU).

RESULTS

In total, 821 sepsis patients were enrolled; 173 patients died within the 28-day follow-up period. Procalcitonin and D-dimer values were used to calculate TIPS because they had the best performance in the prediction of 28-day mortality by receiver operating characteristic curves. The 28-day mortality and the incidence of MV, CD and AICU were significantly higher in patients with higher TIPS. Multivariable logistic regression analysis indicated TIPS was an independent predictor of 28-day mortality, MV and AICU. TIPS performed better than other prognostic scores, including quick sequential organ failure assessment, Modified Early Warning Score and Mortality in Emergency Department Sepsis Score for predicting 28-day mortality, and similar to the Acute Physiology and Chronic Health Evaluation II, but inferior to sequential organ failure assessment.

CONCLUSIONS

TIPS is useful for stratifying the risk of adverse clinical outcomes in sepsis patients shortly after admission to the ED.

Nested case-control study of multiple serological indexes and Brighton pediatric early warming score in predicting death of children with sepsis

BACKGROUND

Currently, it is difficult to predict the complications of children at the early stage of sepsis. Brighton pediatric early warning score (PEWS) is a disease risk assessment system that is simple and easy to operate, which has good sensitivity and specificity in disease recognition among children. Because detection indicators vary widely in children, a single indicator is difficult to assess the post-treatment status of children with sepsis.

AIM

To investigate the relationship between serological markers, Brighton PEWS, and death in children with sepsis after treatment.

METHODS

A total of 205 children diagnosed with sepsis at our hospital were enrolled. The baseline data, serum scores, and PEWS scores were recorded. In the nested case-control study, children who died during the study period were included in an observation group. According to the matching principle, the children who were not dead in the same cohort were included in a control group. The influencing factors of death in children with sepsis after treatment and the value of each evaluation index in predicting the prognosis of children were analyzed.

RESULTS

A total of 96 children were enrolled in the study, including 48 each in the observation group and the control group. Multivariate logistic regression analysis indicated that antibacterial treatments within 1 h (P = 0.017), shock (P = 0.044), multiple organ dysfunction syndrome (MODS) (P = 0.027), serum procalcitonin (PCT) (P = 0.047), serum albumin (ALB) (P = 0.024), and PEWS (P = 0.012) were independent risk factors for the death of children with sepsis. The area under the curve of the combination of ALB, PCT, and PEWS to predict the death in children with sepsis was the highest (0.908).

CONCLUSION

Antibacterial treatments within 1 h, shock, MODS, PCT, ALB, and PEWS are independent risk factors for the death of children with sepsis. The predictive accuracy of the combination of PCT, ALB, and PEWS for the prognosis of children with sepsis is the best.

Bleeding and thrombosis in intensive care patients with thrombocytopenia-Protocol for a topical systematic review

BACKGROUND

Thrombocytopenia is a common condition in critically ill patients in the intensive care unit (ICU). It is associated with prolonged stay in the ICU, increased transfusion requirements, risk of bleeding and mortality. The evidence regarding the use of prophylactic platelet transfusion and thrombosis prophylaxis in patients with thrombocytopenia in the ICU is unknown. To direct future research, we aim to assess the current evidence regarding prophylactic platelet transfusion and thrombosis prophylaxis on patient-important benefits and harms in the ICU population.

METHODS

We will conduct a topical systematic review of all study designs (ie no study design will per se be excluded from the proposed review) in accordance with the Preferred Reporting Items for Systematic and Meta-Analyses (PRISMA) statements. We will include studies on adult patients in the ICU where the incidence of thrombocytopenia and the predefined outcome measures, including mortality, quality-of-life, thrombotic events and haemorrhagic events are reported. We will provide descriptive analyses of the included studies/trials, ie no meta-analyses will be conducted, and the quality of evidence will be assessed according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

CONCLUSION

The outlined topical systematic review will provide important data on the benefits and harms of prophylactic platelet transfusion and thrombosis prophylaxis in ICU patients with thrombocytopenia and provide estimates on the rate of thrombocytopenia in this vulnerable population.

Hippocampus and cerebellum damage in sepsis induced by lipopolysaccharide in aged rats - Pregabalin can prevent damage

BACKGROUNDS

The aim of this study was to investigate the oxidative damage and inflammatory effects in the hippocampus and cerebellum in lipopolysaccharide (LPS)-induced sepsis model and possible ameliorating effects of pregabalin (PG).

METHODS

Twenty four female Wistar Albino rats (12 month old) were divided into 3 groups as follows: Group I (Control; 0.1 ml/gavage and i.p. saline, single dose), Group II (LPS; 5 mg/kg LPS, i.p, single dose), Group III (LPS + PG; 5 mg/kg LPS, i.p, single dose + 30 mg/kg, gavage, single dose). DNA damage, ischemia-modified albumin (IMA), total oxidant status (TOS), total antioxidant status (TAS) oxidative stress index (OSI), leukocyte (WBC), lymphocyte, neutrophil, hemoglobin (HGB), erythrocyte (RBC), and thrombocyte counts were measured in blood and brain tissues. Histopathological and immunohistochemical evaluation of Caspase- 3, G-CSF, IL-6, SAA, iNOS expressions were conducted using hippocampus and cerebellum tissues.

RESULTS

Comet analysis score, lymphocytes, neutrophils, WBC, IMA, TOS and OSI values were increased in Group II compared with to Group I (p < 0.05). IMA levels in blood, TOS and OSI levels in the brain were significantly decreased in Group III compared to Group II (p < 0.05). We observed increased hemorrhages, neutrophils, leukocytes infiltrations and neuron degeneration in Group II compared to Group I. Caspase 3, G-CSF, IL-6, SAA, iNOS expressions were increased in group II compared to Group I (p < 0.001).

CONCLUSION

Pregabalin partly ameliorated the damage caused by the exposure to LPS in hippocampus and cerebellum; however, further studies are needed to determine pregabalin's possible protective effects at different doses and with different techniques.

Respiratory viral infections in infants with possible sepsis

Background

Knowledge of infections leading to sepsis is needed to develop comprehensive infection prevention and sepsis, as well as early recognition and treatment strategies.The aim of this study was to investigate the etiology of sepsis and evaluate the proportion of respiratory viral pathogens in infants under two years of age with possible sepsis.

Methods

The prospective study was performed in two years. Multiplex reverse transcriptase polymerase chain reaction (RT‐PCR) was performed to detect viral pathogens. All patients who were included in this study had sepsis symptoms as defined by the Surviving Sepsis Campaign.

Results

We compared 90 patients with sepsis into three groups as patients (n = 33) who had only viral positivity in nasopharyngeal swab, patients (17) had proven bacterial infection with or without viral infection, and patients (40) without the pathogen detection. Human rhinovirus (16.7%) and influenza (7.8%) were the most commonly seen viruses. A cough was more common in the viral infection group than other groups ( P = 0.02) and median thrombocyte count was lower in the bacterial infection group than the others ( P = 0.01). Patients having bacterial sepsis had the longest duration of hospitalization than the other groups ( P = 0.04). During winter and spring seaons, patients with sepsis had more viral infection; however, in summer and autumn period, patients were mostly in a state that we could not prove infection agents ( P = 0.02).

Conclusions

Our results suggest that respiratory tract viruses may play an important role in patients with sepsis and they should be kept in mind, especially during winter and spring seasons. In overall infection, viral respiratory viruses as a single pathogen with a detection rate of 36.6% in sepsis etiology.

Thrombocytopenia in bacteraemia and association with bacterial species

Thrombocytopenia is common in patients with invasive bacterial infections. Bacteria can activate platelets, but it is unclear if this affects platelet count. The aim of this study was to examine whether bacteraemia with Staphylococcus aureus, which readily activate human platelets, was more likely to be complicated by thrombocytopenia than bacteraemia with Escherichia coli or Streptococcus pneumoniae with different abilities to activate platelets.We compared information from 600 adult patients with community-acquired bacteraemia with S. aureus (n = 140), E. coli (n = 420) and S. pneumoniae (n = 40) in Southern Sweden, 2012, linking information on positive blood cultures from microbiological databases and medical charts. The proportion of patients with thrombocytopenia (platelet count <150 × 109/ml) was calculated. Logistic regression was used to estimate the odds ratios (OR) for thrombocytopenia according to bacterial species adjusted for confounders.The proportion of thrombocytopenia was 29% in S. aureus, 28% in E. coli and 20% in S. pneumonia bacteraemia (P = 0.50), corresponding to an OR of 1.2 (95% confidence interval 0.7-1.9) for thrombocytopenia for S. aureus as compared with E. coli or S. pneumoniae, adjusted for confounders.This study indicates that platelet activation by bacteria is not a major causative mechanism in sepsis-associated thrombocytopenia.

Time course of immature platelet count and its relation to thrombocytopenia and mortality in patients with sepsis

Introduction

The pathogenesis of thrombocytopenia in patients with sepsis is not fully understood. The aims of this study were to investigate changes in thrombopoietic activity over time by using absolute immature platelet counts (AIPC) and to examine the impact of platelet production on thrombocytopenia and mortality in patients with sepsis.

Methods

This retrospective observational study included adult patients with sepsis admitted to the intensive care unit at a university hospital. Two hundred five consecutive sepsis patients were stratified into four groups according to nadir platelet count: severe (nadir ≤40×10³/μL), moderate (41–80×10³/μL), or mild thrombocytopenia (81–120×10³/μL), or normal-increased platelet count (>120×10³/μL). The development of thrombocytopenia was assessed during the first week; mortality was assessed at day 28.

Result

Of the 205 patients included, 61 (29.8%) developed severe thrombocytopenia. On admission, AIPC did not differ among the four groups. In patients with severe thrombocytopenia, AIPC decreased significantly from days 2 to 7, but remained within or above the normal range in the other three groups (overall group comparison, P<0.0001). Multivariate analysis including coagulation biomarkers revealed that AIPC was independently associated with the development of severe thrombocytopenia (day 3 AIPC, odds ratio 0.49 [95% confidence interval (CI) 0.35–0.66], P<0.0001; day 5 AIPC, 0.59 [95% CI 0.45–0.75], P<0.0001). AIPC was a significant predictor of 28-day mortality in Cox hazard models adjusted for Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores (day 3 AIPC, hazard ratio 0.70 [95% CI 0.52–0.89], P = 0.0029; day 5 AIPC, 0.68 [95% CI 0.49–0.87], P = 0.0012).

Conclusions

Thrombopoietic activity was generally maintained in the acute phase of sepsis. However, a decrease in AIPC after admission was independently associated with the development of severe thrombocytopenia and mortality, suggesting the importance of suppressed thrombopoiesis in the pathophysiology of sepsis-induced thrombocytopenia.

Blood platelets and sepsis pathophysiology: A new therapeutic prospect in critically [corrected] ill patients?

Beyond haemostasis, platelets have emerged as versatile effectors of the immune response. The contribution of platelets in inflammation, tissue integrity and defence against infections has considerably widened the spectrum of their role in health and disease. Here, we propose a narrative review that first describes these new platelet attributes. We then examine their relevance to microcirculatory alterations in multi-organ dysfunction, a major sepsis complication. Rapid progresses that are made on the knowledge of novel platelet functions should improve the understanding of thrombocytopenia, a common condition and a predictor of adverse outcome in sepsis, and may provide potential avenues for management and therapy.

How do we approach thrombocytopenia in critically ill patients?

A low platelet count is a frequently encountered haematological abnormality in patients treated in intensive treatment units (ITUs). Although severe thrombocytopenia (platelet count <20 × 10⁹ /l) can be associated with bleeding, even moderate-degree thrombocytopenia is associated with organ failure and adverse prognosis. The aetiology for thrombocytopenia in ITU is often multifactorial and correcting one aetiology may not normalise the low platelet count. The classical view for thrombocytopenia in this setting is consumption associated with thrombin-mediated platelet activation, but other concepts, including platelet adhesion to endothelial cells and leucocytes, platelet aggregation by increased von Willebrand factor release, red cell damage and histone release, and platelet destruction by the complement system, have recently been described. The management of severe thrombocytopenia is platelet transfusion in the presence of active bleeding or invasive procedure, but the risk-benefit of prophylactic platelet transfusions in this setting is uncertain. In this review, the incidence and mechanisms of thrombocytopenia in patients with ITU, its prognostic significance and the impact on organ function is discussed. A practical approach based on the authors' experience is described to guide management of a critically ill patient who develops thrombocytopenia.

The involvement of regulatory non-coding RNAs in sepsis: a systematic review

Background

Sepsis coincides with altered gene expression in different tissues. Accumulating evidence has suggested that microRNAs, long non-coding RNAs, and circular RNAs are important molecules involved in the crosstalk with various pathways pertinent to innate immunity, mitochondrial functions, and apoptosis.

Methods

We searched articles indexed in PubMed (MEDLINE), EMBASE and Europe PubMed Central databases using the Medical Subject Heading (MeSH) or Title/Abstract words (“microRNA”, “long non-coding RNA”, “circular RNA”, “sepsis” and/or “septic shock”) from inception to Sep 2016. Studies investigating the role of host-derived microRNA, long non-coding RNA, and circular RNA in the pathogenesis of and as biomarkers or therapeutics in sepsis were included. Data were extracted in terms of the role of non-coding RNAs in pathogenesis, and their applicability for use as biomarkers or therapeutics in sepsis. Two independent researchers assessed the quality of studies using a modified guideline from the Systematic Review Center for Laboratory animal Experimentation (SYRCLE), a tool based on the Cochrane Collaboration Risk of Bias tool.

Results

Observational studies revealed dysregulation of non-coding RNAs in septic patients. Experimental studies confirmed their crosstalk with JNK/NF-κB and other cellular pathways pertinent to innate immunity, mitochondrial function, and apoptosis. Of the included studies, the SYRCLE scores ranged from 3 to 7 (average score of 4.55). This suggests a moderate risk of bias. Of the 10 articles investigating non-coding RNAs as biomarkers, none of them included a validation cohort. Selective reporting of sensitivity, specificity, and receiver operating curve was common.

Conclusions

Although non-coding RNAs appear to be good candidates as biomarkers and therapeutics for sepsis, their differential expression across tissues complicated the process. Further investigation on organ-specific delivery of these regulatory molecules may be useful.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1555-3) contains supplementary material, which is available to authorized users.

How I evaluate and treat thrombocytopenia in the intensive care unit patient

Multiple causes (pseudothrombocytopenia, hemodilution, increased consumption, decreased production, increased sequestration, and immune-mediated destruction of platelets) alone or in combination make thrombocytopenia very common in intensive care unit (ICU) patients. Persisting thrombocytopenia in critically ill patients is associated with, but not causative of, increased mortality. Identification of the underlying cause is key for management decisions in individual patients. While platelet transfusion might be indicated in patients with impaired platelet production or increased platelet destruction, it could be deleterious in patients with increased intravascular platelet activation. Sepsis and trauma are the most common causes of thrombocytopenia in the ICU. In these patients, treatment of the underlying disease will also increase platelet counts. Heparin-induced thrombocytopenia requires alternative anticoagulation at a therapeutic dose and immune thrombocytopenia immunomodulatory treatment. Thrombocytopenia with symptomatic bleeding at or above World Health Organization grade 2 or planned invasive procedures are established indications for platelet transfusions, while the evidence for a benefit of prophylactic platelet transfusions is weak and controversial. If the platelet count does not increase after transfusion of 2 fresh ABO blood group-identical platelet concentrates (therapeutic units), ongoing platelet consumption and high-titer anti-HLA class I antibodies should be considered. The latter requires transfusion of HLA-compatible platelet concentrates.