Thrombocytopenia and prognosis in intensive care

Serial platelet count as a dynamic prediction marker of hospital mortality among septic patients

Background

Platelets play a critical role in hemostasis and inflammatory diseases. Low platelet count and activity have been reported to be associated with unfavorable prognosis. This study aims to explore the relationship between dynamics in platelet count and in-hospital morality among septic patients and to provide real-time updates on mortality risk to achieve dynamic prediction.

Methods

We conducted a multi-cohort, retrospective, observational study that encompasses data on septic patients in the eICU Collaborative Research Database (eICU-CRD) and the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The joint latent class model (JLCM) was utilized to identify heterogenous platelet count trajectories over time among septic patients. We assessed the association between different trajectory patterns and 28-day in-hospital mortality using a piecewise Cox hazard model within each trajectory. We evaluated the performance of our dynamic prediction model through area under the receiver operating characteristic curve, concordance index (C-index), accuracy, sensitivity, and specificity calculated at predefined time points.

Results

Four subgroups of platelet count trajectories were identified that correspond to distinct in-hospital mortality risk. Including platelet count did not significantly enhance prediction accuracy at early stages (day 1 C-indexDynamic  vs C-indexWeibull: 0.713 vs 0.714). However, our model showed superior performance to the static survival model over time (day 14 C-indexDynamic  vs C-indexWeibull: 0.644 vs 0.617).

Conclusions

For septic patients in an intensive care unit, the rapid decline in platelet counts is a critical prognostic factor, and serial platelet measures are associated with prognosis.

Sepsis-Induced Coagulopathy: A Comprehensive Narrative Review of Pathophysiology, Clinical Presentation, Diagnosis, and Management Strategies

Physiological hemostasis is a balance between pro- and anticoagulant pathways, and in sepsis, this equilibrium is disturbed, resulting in systemic thrombin generation, impaired anticoagulant activity, and suppression of fibrinolysis, a condition termed sepsis-induced coagulopathy (SIC). SIC is a common complication, being present in 24% of patients with sepsis and 66% of patients with septic shock, and is often associated with poor clinical outcomes and high mortality. 1 , 2 Recent preclinical and clinical studies have generated new insights into the molecular pathogenesis of SIC. In this article, we analyze the complex pathophysiology of SIC with a focus on the role of procoagulant innate immune signaling in hemostatic activation--tissue factor production, thrombin generation, endotheliopathy, and impaired antithrombotic functions. We also review clinical presentations of SIC, the diagnostic scoring system and laboratory tests, the current standard of care, and clinical trials evaluating the efficacies of anticoagulant therapies.

Identifying prognostic factors for survival in intensive care unit patients with SIRS or sepsis by machine learning analysis on electronic health records

BACKGROUND

Systemic inflammatory response syndrome (SIRS) and sepsis are the most common causes of in-hospital death. However, the characteristics associated with the improvement in the patient conditions during the ICU stay were not fully elucidated for each population as well as the possible differences between the two.

GOAL

The aim of this study is to highlight the differences between the prognostic clinical features for the survival of patients diagnosed with SIRS and those of patients diagnosed with sepsis by using a multi-variable predictive modeling approach with a reduced set of easily available measurements collected at the admission to the intensive care unit (ICU).

METHODS

Data were collected from 1,257 patients (816 non-sepsis SIRS and 441 sepsis) admitted to the ICU. We compared the performance of five machine learning models in predicting patient survival. Matthews correlation coefficient (MCC) was used to evaluate model performances and feature importance, and by applying Monte Carlo stratified Cross-Validation.

RESULTS

Extreme Gradient Boosting (MCC = 0.489) and Logistic Regression (MCC = 0.533) achieved the highest results for SIRS and sepsis cohorts, respectively. In order of importance, APACHE II, mean platelet volume (MPV), eosinophil counts (EoC), and C-reactive protein (CRP) showed higher importance for predicting sepsis patient survival, whereas, SOFA, APACHE II, platelet counts (PLTC), and CRP obtained higher importance in the SIRS cohort.

CONCLUSION

By using complete blood count parameters as predictors of ICU patient survival, machine learning models can accurately predict the survival of SIRS and sepsis ICU patients. Interestingly, feature importance highlights the role of CRP and APACHE II in both SIRS and sepsis populations. In addition, MPV and EoC are shown to be important features for the sepsis population only, whereas SOFA and PLTC have higher importance for SIRS patients.

Peripheral Veno-Arterial-Extracorporeal Membrane Oxygenation for Refractory Septic Shock in Children: A Multicenter Review

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is utilized as a rescue therapy in the management of pediatric patients with refractory septic shock. Multiple studies support the use of a central cannulation strategy in these patients. This study aimed to assess the survival of and identify mortality risk factors in pediatric patients supported with peripheral veno-arterial (VA) ECMO in the setting of septic shock.

METHODS

We retrospectively reviewed and compared clinical characteristics of 40 pediatric patients supported with peripheral VA ECMO for refractory septic shock, at two tertiary care children's hospitals from 2006 to 2020. Our hypothesis was that peripheral VA ECMO is effective in supporting cardiac function and improving tissue oxygenation in most pediatric patients with refractory septic shock.

RESULTS

The overall rate of survival to discharge was 52.5%, comparable to previously reported survival for pediatric sepsis on ECMO. With the exclusion of patients with an oncologic process, the survival rate rose to 62.5%. There was a statistically significant difference in mean pump flow rates within 2 hours of initiation of ECMO between survivors and non-survivors (98 mL/kg/min vs 76 mL/kg/min, P  =  .050). There was no significant difference between pre-ECMO vasoactive inotropic score (VIS) in survivors and non-survivors. A faster decrease in VIS in the first 24 hours was associated with lower mortality.

CONCLUSIONS

From this large case series, we conclude that peripheral VA ECMO is a safe and effective modality to support pediatric patients with refractory septic shock, provided there is establishment of high ECMO pump flows in the first few hours after cannulation and improvement in the VIS.

Prospective evaluation of bleeding risk among thrombocytopenic patients admitted in intensive care unit

PURPOSE

Bleeding risk evaluation of thrombocytopenic patients admitted in ICU has been poorly investigated.

METHODS

A prospective observational study conducted in an 18-bed medical ICU. Consecutive patients with thrombocytopenia (<150 Giga/L) and no bleeding at admission were included.

RESULTS

Over one year, 91 patients were included, mainly men (63%), with an age of 61 [46-68] years and a SOFA score of 6 [3-8]. Twenty-three patients (25%) had an hemorrhagic event during ICU stay, mainly digestive (n = 9; 39%) and urological (n = 6; 26%). The time between ICU admission and bleeding was 8 [2-19] days. Almost half of bleeding events required vasopressor infusion and a hemostatic procedure. At admission, two variables were significantly different between the Bleeding and No-Bleeding groups: plasma urea level was significantly higher in the Bleeding group (9 [5.1; 13] vs. 13 [8.9; 31] mmol/L; p < 0.001) and the presence of skin purpura was associated with a 3-fold higher risk for bleeding during ICU stay (HR: 3.4 [1.3-8.3]; p < 0.05). In contrast, admission platelet count was not significantly different between the 2 groups (90 [32; 128] vs 62 [36; 103] G/L; p = 0.26).

CONCLUSION

Plasma urea levels and the presence of skin purpura are helpful in identifying thrombocytopenic patients at high-risk of bleeding during ICU stay.

Purification and Activity Evaluation of a Novel Thrombopoietin Mimetic Peptide

The emergence of thrombopoietin mimetic peptides presents a promising therapeutic strategy for addressing thrombocytopenia. This particular study aimed to establish a direct, expeditious, and efficient method for modifying and purifying a novel thrombopoietin mimetic peptide. Precursor proteins were subjected to modification utilizing three distinct fatty acids: C25H42O7N2, C39H66O15N4, and C41H70O15N4. Liquid chromatography analyses demonstrated that C41H70O15N4 yielded the most effective modification results. Mass spectrometry findings validated the correspondence between the theoretical and actual molecular weights of each sample. In vivo experiments conducted on normal mice showcased that the C41H70O15N4 modification group exhibited the highest platelet count, peaking at an impressive 5047 × 109/L. This count was approximately twice that of the peak platelet count observed in the dTMP group and four times higher than the control group. Pharmacokinetic investigations revealed that the C41H70O15N4 modification group displayed the lengthiest half-life among beagles, persisting for 128.5 h. This duration was approximately 28.5 times longer than that of the unmodified dTMP group. These findings underscore the effectiveness of the established C41H70O15N4 modification and purification method in preserving the biological activity of the thrombopoietin mimetic peptide. The novel thrombopoietin mimetic peptide showcased notable attributes of simplicity and cost-effectiveness, while also exhibiting a significant platelet-promoting effect and an extended half-life. Consequently, this novel peptide holds substantial significance for advancing the treatment of thrombocytopenia.

A Low Eosinophil to Platelet Ratio as a Worse Prognostic Index for Emergency Department Attendance in Acute Exacerbation of COPD

Purpose

Identifying prognosis for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is challenging. Eosinophils and platelet are involved in the development of COPD, which may predict adverse events. The objective of this study was to determine the effect of the eosinophil to platelet ratio (EPR) in predicting adverse events in patients with AECOPD who visited the emergency department.

Patients and Methods

The records of patients with AECOPD treated at Dalian Municipal Friendship Hospital from January 2018 to December 2020 were retrospectively reviewed. The relationship between the clinical characteristics and EPR, as cut-off value of 0.755, was evaluated.

Results

A total of 508 patients with an AECOPD (316 male, 192 female) were included. An optimal AUC cutoff of 0.755 for the EPR segregated the patients into 2 groups with significantly different mortality (25.3% vs 5.5%, P < 0.001). The same mortality risk with lower EPR was observed among the patients with emergency room attendance (35.6% vs 11.1%, P < 0.001). A model including EPR <0.755, exacerbation history, PaO2 <60mmHg, PaCO2 >50 mm Hg, hypoalbuminemia and age ≥80 was developed to predict death risk and showed good performance.

Conclusion

During severe COPD exacerbation, an EPR < 0.755 preceding therapy can predict worse outcomes in patients with an AECOPD.

Impact of thrombocytopenia on short-term outcomes in patients undergoing mobile extracorporeal membrane oxygenation support

INTRODUCTION

The prolonged use of extracorporeal membrane oxygenation (ECMO) support is associated with increased consumption of platelets and hemolysis. The prognostic impact of thrombocytopenia prior to and during ECMO support on patient's short-, mid- and long-term outcomes has been critically evaluated and discussed over the last years. However, only few data have been published on thrombocytopenia caused by mobile ECMO support. The aim of this study was to evaluate the impact of thrombocytopenia on short-term outcomes and predictors of in-hospital mortality in patients supported by mobile ECMO for transportation and subsequent weaning in a tertiary centre.

METHODS

This retrospective single-centre study analyzed a total of 117 patients requiring mobile veno-arterial (va) ECMO support and subsequent transportation from referral hospitals to our department from January 2015 until December 2021. A total of 15 patients had to be excluded from the analysis for missing data regarding baseline platelet count. Patients were divided into two groups: thrombocytopenia group (<130 × 109/L, n = 44) and non-thrombocytopenia group (≥130 × 109/L, n = 58). The primary outcome was in-hospital mortality. Secondary outcomes were successful ECMO-weaning, and the incidence of associated complications (bleeding, acute hepatic failure, acute renal failure, dialysis, and septic shock).

RESULTS

The dialysis rate before ECMO initiation was significantly higher (p = .041) in the thrombocytopenia group compared to the non-thrombocytopenia group. The rates of bleeding complications (p = .032) and limb ischemia (p = .003) were significantly higher in patients with low platelet count. Moreover, complication rates of acute hepatic failure (p < .001), acute renal failure (p < .001) and dialysis (p = .033) were significantly higher in the thrombocytopenia group. Also, in-hospital mortality was significantly higher (p = .002) in patients with low platelet count before initiation of ECMO support.

CONCLUSION

Based on the results of the present study, patients with thrombocytopenia prior to mobile vaECMO support may be at significantly higher risk for associated complications and short-term mortality.

Biomarkers to Predict Multiorgan Distress Syndrome and Acute Kidney Injury in Critically Ill Surgical Patients

Background and Objectives: Critically ill surgical patients are susceptible to various postoperative complications, including acute kidney injury (AKI) and multiorgan distress syndrome (MODS). These complications intensify patient suffering and significantly increase morbidity and mortality rates. This study aimed to identify the biomarkers for predicting AKI and MODS in critically ill surgical patients. Materials and Methods: We prospectively enrolled critically ill surgical patients admitted to the intensive care unit via the emergency department between July 2022 and July 2023. A total of 83 patients were recruited, and their data were used to analyze MODS. Three patients who showed decreased creatinine clearance at the initial presentation were excluded from the analysis for AKI. Patient characteristics and laboratory parameters including white blood cell (WBC) count, neutrophil count, delta neutrophil index, urine and serum β2-microglobulin, and urine serum mitochondrial DNA copy number (mtDNAcn) were analyzed to determine the reliable biomarker to predict AKI and MODS. Results: The following parameters were independently correlated with MODS: systolic blood pressure (SBP), initial neutrophil count, and platelet count, according to a logistic regression model. The optimal cut-off values for SBP, initial neutrophil count, and platelet count were 113 mmHg (sensitivity 66.7%; specificity 73.9%), 8.65 (X3) (109/L) (sensitivity 72.2%; specificity 64.6%), and 195.0 (X3) (109/L) (sensitivity 66.7%; specificity 81.5%), respectively. According to the logistic regression model, diastolic blood pressure (DBP) and initial urine mtDNAcn were independently correlated with AKI. The optimal cut-off value for DBP and initial urine mtDNAcn were 68.5 mmHg (sensitivity 61.1%; specificity 79.5%) and 1225.6 copies/μL (sensitivity 55.6%; specificity 95.5%), respectively. Conclusions: SBP, initial neutrophil count, and platelet count were independent predictors of MODS in critically ill patients undergoing surgery. DBP and initial urine mtDNAcn levels were independent predictors of AKI in critically ill surgical patients. Large-scale multicenter prospective studies are needed to confirm our results.

PEAL Score to Predict the Mortality Risk of Cardiogenic Shock in the Emergency Department: An Observational Study

BACKGROUND

The in-hospital mortality of cardiogenic shock (CS) remains high (28% to 45%). As a result, several studies developed prediction models to assess the mortality risk and provide guidance on treatment, including CardShock and IABP-SHOCK II scores, which performed modestly in external validation studies, reflecting the heterogeneity of the CS populations. Few articles established predictive scores of CS based on Asian people with a higher burden of comorbidities than Caucasians. We aimed to describe the clinical characteristics of a contemporary Asian population with CS, identify risk factors, and develop a predictive scoring model.

METHODS

A retrospective observational study was conducted between 2014 and 2019 to collect the patients who presented with all-cause CS in the emergency department of a single medical center in Taiwan. We divided patients into subgroups of CS related to acute myocardial infarction (AMI-CS) or heart failure (HF-CS). The outcome was all-cause 30-day mortality. We built the prediction model based on the hazard ratio of significant variables, and the cutoff point of each predictor was determined using the Youden index. We also assessed the discrimination ability of the risk score using the area under a receiver operating characteristic curve.

RESULTS

We enrolled 225 patients with CS. One hundred and seven patients (47.6%) were due to AMI-CS, and ninety-eight patients among them received reperfusion therapy. Forty-nine patients (21.8%) eventually died within 30 days. Fifty-three patients (23.55%) presented with platelet counts < 155 × 103/μL, which were negatively associated with a 30-day mortality of CS in the restrictive cubic spline plot, even within the normal range of platelet counts. We identified four predictors: platelet counts < 200 × 103/μL (HR 2.574, 95% CI 1.379-4.805, p = 0.003), left ventricular ejection fraction (LVEF) < 40% (HR 2.613, 95% CI 1.020-6.692, p = 0.045), age > 71 years (HR 2.452, 95% CI 1.327-4.531, p = 0.004), and lactate > 2.7 mmol/L (HR 1.967, 95% CI 1.069-3.620, p = 0.030). The risk score ended with a maximum of 5 points and showed an AUC (95% CI) of 0.774 (0.705-0.843) for all patients, 0.781 (0.678-0.883), and 0.759 (0.662-0.855) for AMI-CS and HF-CS sub-groups, respectively, all p < 0.001.

CONCLUSIONS

Based on four parameters, platelet counts, LVEF, age, and lactate (PEAL), this model showed a good predictive performance for all-cause mortality at 30 days in the all patients, AMI-CS, and HF-CS subgroups. The restrictive cubic spline plot showed a significantly negative correlation between initial platelet counts and 30-day mortality risk in the AMI-CS and HF-CS subgroups.

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

PURPOSE

Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients.

METHODS

We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses.

RESULTS

We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4-46.1) had thrombocytopenia; 23.4% (20-26) had thrombocytopenia at ICU admission, and 19.8% (17.6-22.2) developed thrombocytopenia during their ICU stay. Absence of acquired immune deficiency syndrome (AIDS), non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19-2.42).

CONCLUSION

Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.

One-Year Survival for Developing Acute Kidney Injury in Adult Patients with AMI Cardiogenic Shock Receiving Venoarterial Extracorporeal Membrane Oxygenation

Objective

The incidence of cardiogenic shock cases treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support has been on the rise. Acute kidney injury (AKI) is a significant complication of cardiogenic shock and a frequent serious complication in patients requiring ECMO-supported therapy. AKI is strongly associated with unfavorable patient prognosis. However, there is a paucity of data on the influence of AKI on the prognosis of patients with acute myocardial infarction complicated by cardiogenic shock (AMI-CS) who are receiving ECMO support, particularly with regard to long-term outcomes.

Methods

This retrospective observational study included 103 patients in the People's Hospital of Guangxi Zhuang Autonomous Region from January 2017 and June 2022. AKI was defined according to Kidney Disease Improving Global Outcome (KDIGO) criteria. Cox regression and logistic regression were used to identify risk factors.

Results

In this study, the incidence of AKI was 63.11%, with AKI stage 1, 2, and 3 accounting for 21.36%, 12.62%, and 29.13%, respectively. Patients with severe AKI had significantly higher in-hospital mortality (43.33% vs 27.40%, P < 0.001), 30-day mortality (60.00% vs 31.51%, P = 0.001), and 1-year mortality (63.67% vs 34.25%, P<0.001) than those without severe AKI. Furthermore, severe AKI significantly increased the risk of one-year mortality (HR 10.816, CI 3.118-37.512, P<0.001). Baseline serum creatinine, baseline platelet, and active cardiopulmonary resuscitation were independent predictors of one-year mortality. In addition, baseline white blood cell count, baseline aspartate aminotransferase, baseline alanine aminotransferase (ALT), baseline serum creatinine, preoperative lactate, and postoperative mean arterial pressure were independent risk factors of severe AKI during hospitalization.

Conclusion

In patients with AMI-CS receiving ECMO support, AKI is highly prevalent. Development of severe AKI significantly increased the risk of one-year mortality.

Prophylactic platelet transfusion response in critically ill patients: a prospective multicentre observational study

BACKGROUND

Response to prophylactic platelet transfusion is suspected to be inconsistent in critically ill patients questioning how to optimize transfusion practices. This study aimed to describe prophylactic platelet transfusion response, to identify factors associated with a suboptimal response, to analyse the correlation between corrected count increment and platelet count increment and to determine the association between poor platelet transfusion response and clinical outcomes.

METHODS

This prospective multicentre observational study recruited patients who received at least one prophylactic platelet transfusion in one of the nine participating intensive care units for a period up to 16 months. Poor platelet transfusion response was defined as a corrected count increment (CCI) that adjusts for platelet dose and body surface area, less than 7 at 18-24 h after platelet transfusion. Factors associated with poor platelet transfusion response were assessed in a mixed-effect model. Sensitivity analyses were conducted in patients with and without haematology malignancy and chemotherapy.

RESULTS

Poor platelet transfusion response occurred in 349 of the 472 (73.9%) prophylactic platelet transfusions and in 141/181 (77.9%) patients. The mixed-effect model identified haemoglobin at ICU admission (odds ratio (OR): 0.79 [95% confidence interval (CI) 0.7-0.89]) and body mass index (BMI) (OR: 0.93 [0.89-0.98]) being positively and independently associated with platelet transfusion response, while a haematological malignancy (OR 1.93 [1.09-3.43]), sepsis as primary ICU admission diagnosis (OR: 2.81 [1.57-5.03]), SOFA score (OR 1.10 [1.03; 1.17]) and maximum storage duration of platelet (OR: 1.24 [1.02-1.52]) were independently associated with a suboptimal platelet increment. Clinical outcomes did not differ between groups, nor the requirement for red blood cells. Poor platelet transfusion response was found in 93.5% of patients with haematology malignancy and chemotherapy.

CONCLUSIONS

In this study of critically ill patients, of whom more than half had bone marrow failure, almost three quarters of prophylactic platelet transfusions led to suboptimal platelet increment measured 18 to 24 h following platelet transfusion. Platelet storage duration was the only factor associated with poor platelet response that may be accessible to intervention. Trial registration in October 2017: ClinicalTrials.gov: NCT03325140.

Sepsis Induced Coagulopathy: Bringing Science to the Bedside

How to cite this article: Samavedam S, Sepsis Induced Coagulopathy: Bringing Science to the Bedside. Indian J Crit Care Med 2023;27(9): 611-612.

Preliminary Study of sCD14 and sCD163 as Predictors of Disease Severity and ICU Admission in COVID-19: Relation to Hematological Parameters, Blood Morphological Changes and Inflammatory Biomarkers

Background and Objectives

Research supports the role of monocyte/macrophage activation in COVID-19 immunopathology. This study aimed to evaluate sCD14 and sCD163 - the monocyte activation markers - and to investigate their relation to hematological parameters and blood morphology in COVID-19 infection.

Methods

This is a case-control study that included 70 COVID-19 patients. Patients were subdivided into two groups: 23 severely diseased ICU-admitted patients and another group of 47 non-ICU-admitted patients. sCD163 and sCD14 levels were determined using ELISA.

Results

sCD163 and sCD14 showed significantly higher levels in sera of patients compared to the control group, with significantly higher levels of sCD163 in ICU-admitted patients than non-ICU admitted patients. Receiver operating characteristic curve analysis demonstrated the usefulness of sCD163 with a cut-off value of 734 ng/mL as a potential marker to discriminate between ICU and non-ICU admitted COVID-19 patients (sensitivity of 81.16%; specificity of 96.67% and positive predictive value of 98% with area under the curve of 0.930). sCD163 levels showed a positive correlation with total white blood cells, absolute neutrophilic count, Neutrophil/Lymphocyte ratio, and a negative correlation with platelet count. sCD14 levels positively correlated with D-dimer values associated with a shift to the left and neutrophilic toxic granulations in blood morphology.

Conclusion

High sCD163 and sCD14 levels, hematological parameters, and blood morphology reflect monocyte activation in COVID-19 infection. sCD163 is a potential marker of disease severity. These findings support further study of therapeutics targeting macrophage activity in COVID-19 patients with high sCD163 levels.

Thrombocytopenia is associated with a dysregulated host response in severe COVID-19

BACKGROUND

Thrombocytopenia is associated with increased mortality in COVID-19 patients.

OBJECTIVE

To determine the association between thrombocytopenia and alterations in host response pathways implicated in disease pathogenesis in patients with severe COVID-19.

PATIENTS/METHODS

We studied COVID-19 patients admitted to a general hospital ward included in a national (CovidPredict) cohort derived from 13 hospitals in the Netherlands. In a subgroup, 43 host response biomarkers providing insight in aberrations in distinct pathophysiological domains (coagulation and endothelial cell function; inflammation and damage; cytokines and chemokines) were determined in plasma obtained at a single time point within 48 h after admission. Patients were stratified in those with normal platelet counts (150-400 × 109/L) and those with thrombocytopenia (<150 × 109/L).

RESULTS

6.864 patients were enrolled in the national cohort, of whom 1.348 had thrombocytopenia and 5.516 had normal platelets counts; the biomarker cohort consisted of 429 patients, of whom 85 with thrombocytopenia and 344 with normal platelet counts. Plasma D-dimer levels were not different in thrombocytopenia, although patients with moderate-severe thrombocytopenia (<100 × 109/L) showed higher D-dimer levels, indicating enhanced coagulation activation. Patients with thrombocytopenia had lower plasma levels of many proinflammatory cytokines and chemokines, and antiviral mediators, suggesting involvement of platelets in inflammation and antiviral immunity. Thrombocytopenia was associated with alterations in endothelial cell biomarkers indicative of enhanced activation and a relatively preserved glycocalyx integrity.

CONCLUSION

Thrombocytopenia in hospitalized patients with severe COVID-19 is associated with broad host response changes across several pathophysiological domains. These results suggest a role of platelets in the immune response during severe COVID-19.

Clinical significance of thrombocytopenia in patients with septic shock: An observational retrospective study

PURPOSE

Whether thrombocytopenia in critically ill patients accounts for a bystander of severity or drives specific complications is unclear. We addressed the effect of thrombocytopenia on septic shock, with emphasis on intensive care unit (ICU)-acquired bleeding, infections and thrombotic complications.

MATERIALS AND METHODS

A retrospective (2008-2019) single-center study of patients with septic shock. Thrombocytopenia was assessed over the first seven days and was defined as severe (nadir <50 G/L), mild (nadir 50-150 G/L) and relative (30% decrease with nadir >150 G/L). Outcomes were ICU mortality and ICU-acquired complications defined by severe bleeding, infections and thrombotic events during the ICU stay.

RESULTS

The study comprised 1024 patients. Severe, mild and relative thrombocytopenia occurred in 33%, 40% and 9% of patients. The in-ICU mortality rate was 27%, independently associated with severe thrombocytopenia. ICU-acquired infections, hemorrhagic and thrombotic complications occurred in 27.5%, 13.3% and 11.6% of patients, respectively. Patients with severe, mild or relative thrombocytopenia exhibited higher incidences of bleeding events (20.3%, 15.3% and 14.4% vs. 3.6% in non-thrombocytopenic, p < 0.001), infections (35.2%, 21.9% and 33.3% vs. 23.1% in non-thrombocytopenic, p < 0.001) and thrombotic events (14.6%, 10.8% and 17.8% vs. 7.8% in non-thrombocytopenic, p = 0.03). Only severe thrombocytopenia remained independently associated with increased risk of bleeding.

CONCLUSIONS

Severe thrombocytopenia was independently associated with ICU mortality and increased risk of bleeding, but not with infectious and thrombotic events.

Prognostic Value of Routine Biomarkers in the Early Stage of COVID-19

Various biomarkers like certain complete blood cell count parameters and the derived ratios including neutrophil-lymphocyte ratio are commonly used to evaluate disease severity. Our study aimed to establish if baseline levels of complete blood cell count-derived biomarkers and CRP, measured before any treatment which can interfere with their values, could serve as a predictor of development of pneumonia and the need for hospitalization requiring oxygen therapy. We retrospectively analyzed the laboratory data of 200 consecutive patients without comorbidities, who denied usage of medications prior to blood analysis and visited a COVID-19 ambulance between October and December 2021. Multivariate regression analysis extracted older age, elevated CRP and lower eosinophil count as significant independent predictors of pneumonia (p = 0.003, p = 0.000, p = 0.046, respectively). Independent predictors of hospitalization were higher CRP (p = 0.000) and lower platelet count (p = 0.005). There was no significant difference in the neutrophil-lymphocyte and platelet-lymphocyte ratios between examined groups. Individual biomarkers such as platelet and eosinophil count might be better in predicting the severity of COVID-19 than the neutrophil-lymphocyte and platelet-lymphocyte ratios.

Development and Validation Nomogram for Predicting the Survival of Patients with Thrombocytopenia in Intensive Care Units

Background

The number of patients with thrombocytopenia (TCP) is relatively high in intensive care units (ICUs). It is therefore necessary to evaluate the prognostic risk of such patients.

Aim

This study investigated the risk factors affecting the survival of patients with TCP in the ICU. Using the findings of this investigation, we developed and validated a risk prediction model.

Methods

We evaluated patients admitted to the ICU who presented with TCP. We used LASSO regression to identify important clinical indicators. Based on these indicators, we developed a prediction model complete with a nomogram for the development cohort set. We then evaluated the mode's accuracy using a receiver operating characteristic (ROC) curve, calibration curves, and decision curve analysis (DCA) in a validation cohort.

Results

A total of 141 cases of ICU TCP were included in the sample, of which 47 involved death of the patient. Clinical results were as follows: N (HR 0.91, 95% CI 0.86-0.97, P=0.003); TBIL (HR 1.98, 95% CI 1.02-1.99, P=0.048); APACHE II (HR 1.94, 95% CI 1.39, 2.48, P=0.045); WPRN (HR 6.22, 95% CI 2.86-13.53, P<0.001); WTOST (HR 0.56, 95% CI 0.21-1.46, P<0.001); and DMV [HR1.87, 95% CI 1.12-2.33]. The prediction model yielded an area under the curve (AUC) of 0.918 (95% CI 0.863-0.974) in the development cohort and 0.926 (95% CI 0.849-0.994) in the validation cohort. Application of the nomogram in the validation cohort gave good discrimination (C-index 0.853, 95% CI 0.810-0.922) and good calibration. DCA indicated that the nomogram was clinically useful.

Conclusion

The individualized nomogram developed through our analysis demonstrated effective prognostic prediction for patients with TCP in ICUs. Use of this prediction metric may reduce TCP-related morbidity and mortality in ICUs.

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.

Role of Routine Blood Parameters in Predicting Mortality Among Surgical Patients With Sepsis

BACKGROUND

Outcome prediction for surgical patients with sepsis may be conducive to early aggressive interventions. In several studies, changes in the level of numerous biomarkers like red cell distribution width (RDW), platelet count (PC), mean platelet volume (MPV), and platelet distribution width (PDW) have been demonstrated to be associated with mortality in critically ill patients. We aimed at investigating the prognostic significance of dynamic changes in RDW, PC, MPV, and PDW in surgical patients with sepsis.

METHODS

We prospectively enrolled 110 surgical patients of sepsis in our study admitted to the surgical ward and ICU. We measured RDW, PC, MPV, and PDW on days 1, day 4, and day 8. Receiver operating characteristics (ROC) were generated for prognostic validation of these parameters and mortality in surgical patients with sepsis.  Results: We found that higher RDW and PDW on day 1 among non-survivors as compared to survivors on day 1 were significantly associated with mortality. ROC curves showed that RDW and PDW on day 1 could be used to predict mortality in surgical patients with sepsis and it was dynamic changes in PC on day 4 and day 8 along with a change in MPV on day 8, which was significantly associated with mortality.

CONCLUSION

The major findings of our study were baseline value of RDW and PDW on day 1 and continuous decrease in PC and increase in MPV over one week were significantly associated with mortality. So, it is better to monitor dynamic changes in PC and MPV in combination with baseline RDW and PDW. So, these parameters can be promising markers to assess prognosis in surgical patients with sepsis.

Prognostic factors for patients with hematologic malignancies admitted to the intensive care unit: is allogeneic transplantation still a risk factor?

The rate of intensive care unit (ICU) mortality in patients with hematologic malignancies is high. The risk factors for this were inconsistent across several previous studies, and there is currently no accepted consensus around risk factors for these patients. We aimed to identify which prognostic factors were associated with ICU mortality in critically ill patients with hematologic malignancies, nearly half of which were allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. In addition, we aimed to compare the characteristics and clinical outcomes of patients with and without allogenic allo-HSCT. In total, 217 patients with hematologic malignancies were enrolled consecutive, 119 (54.8%) of whom underwent HSCT (allo-HSCT: n = 115). All survivors were followed up with until August 1, 2022. The rate of ICU mortality in this cohort was 54.4%: 55.5 and 53.1% for the patients with and without HSCT, respectively (p = 0.724). The probabilities of survival after ICU admission were also comparable between the patients who had allo-HSCT and those who did not. A multivariable analysis revealed that cerebrovascular disease, hyperlactic acidemia on the day of ICU admission, lower platelet count, use of vasoactive drugs, and absence of noninvasive ventilation on the day of ICU admission were independent risk factors for ICU mortality. For patients with three to five of these risk factors, the rate of ICU mortality was as high as 84.6%, which was significantly higher than that of other patients. In this study, the ICU mortality rate in patients with hematologic malignancies was still high, particularly for those with multiple risk factors. However, allo-HSCT was not found to be a risk factor for ICU mortality.

Investigating and imaging platelets in inflammation

Blood platelets are best known for their roles in hemostasis and thrombosis, but platelets also make important contributions to inflammation, immunity, and inflammatory resolution. Experiments involving depletion, genetic modification, and live imaging of platelets in animal models have increased our mechanistic understanding of platelet contributions to inflammation. In this minireview, we provide a critical overview of experimental techniques for manipulating and imaging platelets in inflammation models. We then highlight studies using innovative approaches to elucidate molecular mechanisms through which platelet subsets, platelet Fc gamma receptors, and pro-resolution platelet functions influence inflammatory responses. We also propose future technologies and research directions which might move us closer to harnessing of platelet functions for improved therapeutic modulation of inflammatory diseases.

Applications of Artificial Intelligence in Thrombocytopenia

Thrombocytopenia is a medical condition where blood platelet count drops very low. This drop in platelet count can be attributed to many causes including medication, sepsis, viral infections, and autoimmunity. Clinically, the presence of thrombocytopenia might be very dangerous and is associated with poor outcomes of patients due to excessive bleeding if not addressed quickly enough. Hence, early detection and evaluation of thrombocytopenia is essential for rapid and appropriate intervention for these patients. Since artificial intelligence is able to combine and evaluate many linear and nonlinear variables simultaneously, it has shown great potential in its application in the early diagnosis, assessing the prognosis and predicting the distribution of patients with thrombocytopenia. In this review, we conducted a search across four databases and identified a total of 13 original articles that looked at the use of many machine learning algorithms in the diagnosis, prognosis, and distribution of various types of thrombocytopenia. We summarized the methods and findings of each article in this review. The included studies showed that artificial intelligence can potentially enhance the clinical approaches used in the diagnosis, prognosis, and treatment of thrombocytopenia.

In vitro Effect of Dalteparin and Argatroban on Hemostasis in Critically Ill Sepsis Patients with New-Onset Thrombocytopenia

Thrombocytopenia is common among critically ill sepsis patients, while they also hold an increased risk for thromboembolic events. Thus, the choice of anticoagulant prophylaxis for this patient population is challenging. We investigated the in vitro effect of low-molecular-weight heparin (dalteparin) and direct thrombin inhibitor (argatroban) on the hemostasis in blood from sepsis patients with new-onset thrombocytopenia. Thrombocytopenia was defined as a platelet count drop of ≥30% and/or from >100 × 10 ⁹ /L to 30 to 100 × 10 ⁹ /L within 24 hours prior to inclusion. We included five healthy individuals and ten patients. Analyses of thrombin generation (Calibrated Automated Thrombogram), thrombin-antithrombin (TAT) complex levels, prothrombin fragment 1+2 (F1+2), and rotational thromboelastometry (ROTEM) were performed. Based on dose-response relationships investigated in healthy blood, patient samples were spiked with prophylactic (0.25 IU/mL) and therapeutic (0.75 IU/mL) dalteparin and low (0.25 µg/mL) and high (0.50 µg/mL) argatroban concentrations, each with a sample without anticoagulant. In patients, the endogenous thrombin potential was markedly lower in therapeutic dalteparin samples than in samples without anticoagulant [median (range): 29 (0-388) vs. 795 (98-2121) nM × min]. In high argatroban concentration samples, thrombin lag time was longer than in samples without anticoagulant [median (range): 15.5 (10.5-20.2) versus 5.3 (2.8-7.3) min]. Dalteparin and argatroban both increased clotting time but did not affect maximum clot firmness in the ROTEM INTEM assay. Six patients had elevated TAT and eight patients had elevated F1 + 2. In conclusion, dalteparin mainly affected the amount of thrombin generated and argatroban delayed clot initiation in critically ill sepsis patients with new-onset thrombocytopenia. Neither anticoagulant affected clot strength.

Sepsis-Induced Coagulopathy: An Update on Pathophysiology, Biomarkers, and Current Guidelines

Significant cross talk occurs between inflammation and coagulation. Thus, coagulopathy is common in sepsis, potentially aggravating the prognosis. Initially, septic patients tend to exhibit a prothrombotic state through extrinsic pathway activation, cytokine-induced coagulation amplification, anticoagulant pathways suppression, and fibrinolysis impairment. In late sepsis stages, with the establishment of disseminated intravascular coagulation (DIC), hypocoagulability ensues. Traditional laboratory findings of sepsis, including thrombocytopenia, increased prothrombin time (PT) and fibrin degradation products (FDPs), and decreased fibrinogen, only present late in the course of sepsis. A recently introduced definition of sepsis-induced coagulopathy (SIC) aims to identify patients at an earlier stage when changes to coagulation status are still reversible. Nonconventional assays, such as the measurement of anticoagulant proteins and nuclear material levels, and viscoelastic studies, have shown promising sensitivity and specificity in detecting patients at risk for DIC, allowing for timely therapeutic interventions. This review outlines current insights into the pathophysiological mechanisms and diagnostic options of SIC.

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.

Platelet transfusions and thrombocytopenia in intensive care units: protocol for an international inception cohort study (PLOT‐ICU)

Introduction

Thrombocytopenia is frequent in intensive care unit (ICU) patients and has been associated with worse outcome. Platelet transfusions are often used in the management of ICU patients with severe thrombocytopenia. However, the reported frequencies of thrombocytopenia and platelet transfusion practices in the ICU vary considerably. Therefore, we aim to provide contemporary epidemiological data on thrombocytopenia and platelet transfusion practices in the ICU.

Methods

We will conduct an international inception cohort, including at least 1000 acutely admitted adult ICU patients. Routinely available data will be collected at baseline (ICU admission), and daily during ICU stay up to a maximum of 90 days. The primary outcome will be the number of patients with thrombocytopenia (a recorded platelet count < 150 × 10⁹/L) at baseline and/or during ICU stay. Secondary outcomes include mortality, days alive and out of hospital, days alive without life‐support, the number of patients with at least one bleeding episode, at least one thromboembolic event and at least one platelet transfusion in the ICU, the number of platelet transfusions and the indications for transfusion. The primary and secondary outcomes will be presented descriptively. In addition, we will assess risk factors for developing thrombocytopenia during ICU stay and the association between thrombocytopenia at baseline and 90‐day mortality using logistic regression analyses.

Conclusion

The outlined international PLOT‐ICU cohort study will provide contemporary epidemiological data on the burden and clinical significance of thrombocytopenia in adult ICU patients and describe the current platelet transfusion practice.

Platelet Count in Patients with SARS-CoV-2 Infection: A Prognostic Factor in COVID-19

COVID-19 patients may manifest thrombocytopenia and some of these patients succumb to infection due to coagulopathy. The aim of our study was to examine platelet count values in patients infected with SARS-CoV-2, comparing them to a control group consisting of non-COVID-19 patients. Moreover, we evaluated the correlation between the platelet value and the respiratory alteration parameters and the outcome (hospitalization and mortality) in COVID-19 patients. The mean platelet values (×109/L) differed between patients with positive or negative SARS-CoV-2 swabs (242.1 ± 92.1 in SARS-CoV-2 negative vs. 215.2 ± 82.8 in COVID-19 patients, p < 0.001). In COVID-19 patients, the platelet count correlated with the A-aO2 gradient (p = 0.001, rho = −0.149), with its increase over the expected (p = 0.013; rho = −0.115), with the PaO2 values (p = 0.036; rho = 0.093), with the PCO2 values (p = 0.003; rho = 0.134) and with the pH values (p = 0.016; rho = −0.108). In COVID-19 negative patients, the platelet values correlated only with the A-aO2 gradient: (p = 0.028; rho = −0.101). Patients discharged from emergency department had a mean platelet value of 234.3 ± 68.7, those hospitalized in ordinary wards had a mean value of 204.3 ± 82.5 and in patients admitted to sub-intensive/intensive care, the mean value was 201.7 ± 75.1. In COVID-19 patients, the survivors had an average platelet value at entry to the emergency department of 220.1 ± 81.4, while that of those who died was 206.4 ± 87.7. Our data confirm that SARS-CoV-2 infection may induce thrombocytopenia, and that the reduction in platelet counts could be correlated with the main blood gas parameters and with clinical outcome; as a consequence, platelet count could be an important prognostic factor to evaluate and stratify COVID-19 patients.

Severe Thrombocytopenia Caused by Vancomycin in the Intensive Care Unit: A Case Report

Thrombocytopenia can cause substantial morbidity and mortality in critically ill patients. There are multiple etiology factors and various mechanisms associated with thrombocytopenia, of which drug-induced thrombocytopenia (DITP) deserves attention. Herein, we describe a case of severe thrombocytopenia during intensive care unit (ICU) hospitalization that was likely to be associated with vancomycin. By revealing the process of identifying this case of DITP and reviewing relevant clinical studies, a risk alert of vancomycin-related severe hematotoxicity should be considered.

Antimicrobial safety considerations in critically ill patients: part II: focused on anti-microbial toxicities

INTRODUCTION

Antibiotic prescription is a challenging issue in critical care settings. Different pharmacokinetic and pharmacodynamic properties, polypharmacy, drug interactions, and high incidence of multidrug-resistant microorganisms in this population can influence the selection, safety, and efficacy of prescribed antibiotics.

AREAS COVERED

In the current article we searched PubMed, Scopus and Google Scholar for neurotoxicities, hematologic toxicity and fluid stewardship in intensive care units.

EXPERT OPINION

Critically ill patients who receive antimicrobial agents should be monitored for neurological, hematologic toxicities especially seizure, thrombocytopenia, and clostridioides infections. Other toxicities including QTc prolongation, electrolyte disturbances, liver enzyme elevation, and infusion-related reactions were being considered. Other changes, including fluid overload, hypoalbuminemia, augmented renal clearance, increased cardiac outputs in septic shock, and acute kidney injury, may influence treatment efficiency and patient outcome.

Association of platelet count with mortality in patients with infectious diseases in intensive care unit: a multicenter retrospective cohort study

Platelets play important roles in thrombosis, hemostasis, inflammation, and infection. We aimed to evaluate the association between platelet count and its variation trend and prognosis of patient with infectious diseases in intensive care units (ICUs). This retrospective cohort study extracted 4,251 critically ill adult patients with infectious diseases from the eICU Collaborative Research Database, whose platelet counts were measured daily during the first 7 days after admission. In the survivors, platelet counts decreased in the first days after admission, reached a nadir on day 3, and then returned and continued to rise above the admission value. In non-survivors, the platelet counts decreased after admission, without a subsequent upturn. We defined three subgroups according to the nadir platelet counts within 7 days: ≤50, 50-130, and ≥130 × 10⁹/L, corresponding to high, intermediate, and low ICU mortality. A decreased platelet count was associated with increased ICU mortality (intermediate vs. low: 1.676 [1.285-2.187]; high vs. low: 3.632 [2.611-5.052]). In conclusion, during the first 7 days, platelet counts decreased after ICU admission, while increased subsequently in the survivors but not in the non-survivors. ICU mortality risk increased as nadir platelet count decreased below 130 × 10⁹/L, and further boosted when it reached below 50 × 10⁹/L.

Non-heparin-induced thrombocytopenia in patients after open-heart surgery

BACKGROUND

Thrombocytopenia (platelet count below 150 x 10³/μL) is a common finding after open-heart surgery and can lead to various complications, including patient death. This study aimed to determine the extent of non-heparin-induced thrombocytopenia in open-heart surgery and to highlight the associated factors.

MATERIALS AND METHODS

In this cohort study, 842 patients who underwent valve and/or coronary bypass surgery over a 5-year period were retrospectively analyzed. After open-heart surgery, patients whose platelet count was less than 150 x 10³/μL on a complete blood count 12 and 24 h after surgery were classified as thrombocytopenic. Three hundred twenty patients without thrombocytopenia and 21 patients with a high probability of heparin-induced thrombocytopenia were excluded from the study. Logistic regression analysis was used to assess the association of independent variables in moderate-severe thrombocytopenia: Age groups, sex, underlying disease, symptoms, type of surgery, pump time, pulsatile or non-pulsatile duration, degree of hypothermia, hemodilution, oxygenator type, use of an intra-aortic balloon, and erythrocyte transfusion counts were included in the analysis.

RESULTS

A total of 501 patients were diagnosed as having non-heparin-induced thrombocytopenia, and 64.3% were male. Three hundred seventy-seven (75.2%) patients had mild thrombocytopenia and 124 (24.7%) had moderate-severe thrombocytopenia. The postoperative platelet count was significantly lower than the preoperative platelet count (213 x 10³ vs.117 x 10³/μL; p < 0.001). Moderate-severe thrombocytopenia was associated with age ≥80 years odds (OR = 9.026, 95% CI: [1.757-46.363]; p = 0.008), isolated valve surgery (OR = 3.090, 95% CI: [1.867-5.114]; p < 0.001), and valve surgery with coronary bypass (OR = 4.938, 95% CI: [1.638-14.889]; p = 0.005) compared to isolated coronary bypass, type of oxygenator (Nipro vital compared with Affinity OR = 11.097, 95% CI: [1.923-64.023]; p = 0.007), erythrocyte transfusion count (OR = 1.219, 95%CI: [1.046-1.420]; p = 0.011).

CONCLUSION

Age 80 years or older, surgical procedures including heart-valve surgery, and the number of red blood cell transfusions are associated with the risk of moderate-to-severe thrombocytopenia. This study provides a guide in terms of risk factors that may lead to moderate-to-severe thrombocytopenia after open-heart surgery. However, future multicentre prospective randomized studies may provide more detailed information on this subject.

Impact of Platelet Transfusion Thresholds on Outcomes of Patients With Sepsis: Analysis of the MIMIC-IV Database

BACKGROUND

The benefits of platelet thresholds for transfusion remain unclear. This study assessed the effect of two transfusion thresholds on the survival outcomes of patients with sepsis and thrombocytopenia.

METHODS

In this retrospective cohort study, data of patients with sepsis admitted to an intensive care unit (ICU) and who had received platelet transfusion were extracted from the Medical Information Mart for Intensive Care IV database. Patients were classified into the lower-threshold group (below 20,000/μL) and higher-threshold group (20,000-50,000/μL), based on thresholds calculated from their pretransfusion platelet count. The endpoints included 28- and 90-day mortality, red blood cell (RBC) transfusion, ICU-free days, and hospital-free days.

RESULTS

There were 76 and 217 patients in the lower-threshold and higher-threshold groups, respectively. The higher-threshold group had a higher rate of surgical ICU admission (35.0% vs. 9.2%) and lower quick Sequential Organ Failure Assessment (qSOFA) score than the lower-threshold group. In the higher-threshold group, 94 (43.3%) and 132 (60.8%) patients died within 28 and 90 days, compared to 51 (67.1%) and 63 (82.9%) patients in the lower-threshold group (adjusted odds ratio, 1.96; 95% confidence interval, 1.16 to 3.03; P = 0.012; adjusted odds ratio, 2.04; 95% confidence interval, 1.16 to 3.57; P = 0.012, respectively). After stratification by mortality risk, the subgroup analysis showed a consistent trend favoring higher-threshold transfusion but reached statistical significance only in the low-risk group. There were no differences in red blood cell transfusion, ICU-free days, and hospital-free days between the groups. The E-value analysis suggested robustness to unmeasured confounding.

CONCLUSIONS

In patients with sepsis and thrombocytopenia, platelet transfusion at a higher threshold was associated with a greater reduction in the 28- and 90-day mortalities than that at a lower threshold.

Sepsis promotes splenic production of a protective platelet pool with high CD40 ligand expression

Platelets have a wide range of functions including critical roles in hemostasis, thrombosis, and immunity. We hypothesized that during acute inflammation, such as in life-threatening sepsis, there are fundamental changes in the sites of platelet production and phenotypes of resultant platelets. Here, we showed during sepsis that the spleen was a major site of megakaryopoiesis and platelet production. Sepsis provoked an adrenergic-dependent mobilization of megakaryocyte-erythrocyte progenitors (MEPs) from the bone marrow to the spleen, where IL-3 induced their differentiation into megakaryocytes (MKs). In the spleen, immune-skewed MKs produced a CD40 ligandhi platelet population with potent immunomodulatory functions. Transfusions of post-sepsis platelets enriched from splenic production enhanced immune responses and reduced overall mortality in sepsis-challenged animals. These findings identify a spleen-derived protective platelet population that may be broadly immunomodulatory in acute inflammatory states such as sepsis.

Characterization of platelet concentrations and evaluation of risk factors for thrombocytopenia following traumatic injury

Introduction

Thrombocytopenia is common in critically ill trauma patients and can lead to potentially broad differentials, including major bleeding, hemodilution, extracorporeal circuit losses, heparin-induced thrombocytopenia, and more. Understanding the normal time course of platelet decline and recovery may delineate thrombocytopenia(HIT) secondary to traumatic injury versus other inciting factors.

Methods

This retrospective study included trauma patients admitted over a 1-year period. The primary aim was characterizing the effect of trauma on platelet concentration and thrombocytopenia incidence in the first 30 days following injury. Thrombocytopenia was defined as platelet concentration <150 × 109/L. A secondary aim was evaluating significant factors contributing to thrombocytopenia.

Results

A total of 225 patients were included. Thrombocytopenia occurred in 67.3% of patients, and a platelet decline of 50% or greater occurred in 44%. Decrease in platelet concentration was significant from day 1 to day 4 (mean ± SD, 232 ± 86 vs 142 ± 76 × 109/L; p = .001). Platelets recovered to baseline on day 8 and peaked on day 16. Packed red blood cell or platelet transfusion, continuous renal replacement therapy, and acute liver injury independently predicted a ≥50% platelet decrease. HIT was not diagnosed in any patients.

Conclusion

Platelet nadir likely occurs approximately 4 days after injury and recovers relatively quickly thereafter. More studies are needed to evaluate the magnitude of effect on thrombocytopenia by factors beyond trauma.

Pandemic coronavirus disease (Covid-19): World effects analysis and prediction using machine-learning techniques

Pandemic novel Coronavirus (Covid-19) is an infectious disease that primarily spreads by droplets of nose discharge when sneezing and saliva from the mouth when coughing, that had first been reported in Wuhan, China in December 2019. Covid-19 became a global pandemic, which led to a harmful impact on the world. Many predictive models of Covid-19 are being proposed by academic researchers around the world to take the foremost decisions and enforce the appropriate control measures. Due to the lack of accurate Covid-19 records and uncertainty, the standard techniques are being failed to correctly predict the epidemic global effects. To address this issue, we present an Artificial Intelligence (AI)-based meta-analysis to predict the trend of epidemic Covid-19 over the world. The powerful machine learning algorithms namely Naïve Bayes, Support Vector Machine (SVM) and Linear Regression were applied on real time-series dataset, which holds the global record of confirmed, recovered, deaths and active cases of Covid-19 outbreak. Statistical analysis has also been conducted to present various facts regarding Covid-19 observed symptoms, a list of Top-20 Coronavirus affected countries and a number of coactive cases over the world. Among the three machine learning techniques investigated, Naïve Bayes produced promising results to predict Covid-19 future trends with less Mean Absolute Error (MAE) and Mean Squared Error (MSE). The less value of MAE and MSE strongly represent the effectiveness of the Naïve Bayes regression technique. Although, the global footprint of this pandemic is still uncertain. This study demonstrates the various trends and future growth of the global pandemic for a proactive response from the citizens and governments of countries. This paper sets the initial benchmark to demonstrate the capability of machine learning for outbreak prediction.

Continuous Versus Intermittent Linezolid Infusion for Critically Ill Patients with Hospital-Acquired and Ventilator-Associated Pneumonia: Efficacy and Safety Challenges

High variability of linezolid blood concentrations with partial subtherapeutic levels was observed in critically ill patients who received a standard intravenous dose of linezolid, contributing to drug resistance and toxicity. Continuous infusions of linezolid have been suggested as an alternative and provide good serum and alveolar levels without fluctuations in trough concentration. This study aimed to assess the effectiveness and safety of continuous linezolid infusion versus the standard regimen in critically ill patients. A prospective randomized controlled study was conducted on 179 patients with nosocomial pneumonia. Patients were randomized into two groups. The first group received IV linezolid 600 mg twice daily, while the second group received 600 mg IV as a loading dose, followed by a continuous infusion of 1200 mg/day (50 mg/h) for at least 8−10 days. The continuous infusion group showed a higher clinical cure rate than the intermittent infusion group (p = 0.046). Furthermore, efficacy was proven by greater improvement of P/F ratio (p = 0.030) on day 7 of treatment, a lower incidence of developing sepsis after beginning treatment (p = 0.009), and a shorter time to reach clinical cure (p < 0.001). Hematological parameters were also assessed during the treatment to evaluate the safety between the two groups. The incidence of thrombocytopenia was significantly lower in the continuous infusion group than in the intermittent infusion group. In addition, a stepwise logistic regression model revealed that the intermittent infusion of linezolid was significantly associated with thrombocytopenia (OR =4.128; 95% CI = 1.681−10.139; p =0.001). The current study is the first to assess the clinical aspects of continuous infusion of linezolid beyond pharmacokinetic studies. Continuous infusion of linezolid outperforms intermittent delivery in safety and improves clinical effectiveness in critically ill patients with Gram-positive nosocomial pneumonia.

Biomarkers Predicting Tissue Pharmacokinetics of Antimicrobials in Sepsis: A Review

The pathophysiology of sepsis alters drug pharmacokinetics, resulting in inadequate drug exposure and target-site concentration. Suboptimal exposure leads to treatment failure and the development of antimicrobial resistance. Therefore, we seek to optimize antimicrobial therapy in sepsis by selecting the right drug and the correct dosage. A prerequisite for achieving this goal is characterization and understanding of the mechanisms of pharmacokinetic alterations. However, most infections take place not in blood but in different body compartments. Since tissue pharmacokinetic assessment is not feasible in daily practice, we need to tailor antibiotic treatment according to the specific patient’s pathophysiological processes. The complex pathophysiology of sepsis and the ineffectiveness of current targeted therapies suggest that treatments guided by biomarkers predicting target-site concentration could provide a new therapeutic strategy. Inflammation, endothelial and coagulation activation markers, and blood flow parameters might be indicators of impaired tissue distribution. Moreover, hepatic and renal dysfunction biomarkers can predict not only drug metabolism and clearance but also drug distribution. Identification of the right biomarkers can direct drug dosing and provide timely feedback on its effectiveness. Therefore, this might decrease antibiotic resistance and the mortality of critically ill patients. This article fills the literature gap by characterizing patient biomarkers that might be used to predict unbound plasma-to-tissue drug distribution in critically ill patients. Although all biomarkers must be clinically evaluated with the ultimate goal of combining them in a clinically feasible scoring system, we support the concept that the appropriate biomarkers could be used to direct targeted antibiotic dosing.

Risk Factors for a Hospital-Acquired Carbapenem-Resistant Klebsiella pneumoniae Bloodstream Infection: A Five-Year Retrospective Study

Purpose

This study aimed to describe trends in Klebsiella pneumoniae (KP) resistance in bloodstream infections (BSI) and to identify risk factors for a hospital-acquired carbapenem-resistant Klebsiella pneumoniae (CRKP) BSI and 28-day mortality from a hospital-acquired KP BSI.

Patients and Methods

We recorded the results of antimicrobial susceptibility testing of 396 KP-positive blood cultures from January 2016 to December 2020. A total of 277 patients with a KP BSI were included in this study, of which 171 had a hospital-acquired infection and 84 had a hospital-acquired CRKP BSI. Multivariate logistic regression analysis was used to identify risk factors for a hospital-acquired CRKP BSI and 28-day mortality from a hospital-acquired KP BSI.

Results

The proportion of hospital-acquired infections among KP BSI patients increased from 53.1% in 2016 to 72.8% in 2020. The detection rate of CRKP among KP BSI patients increased from 18.8% in 2016 to 37.7% in 2020. Multivariate logistic regression showed that β-lactam/β-lactamase inhibitor combinations (BLBLIs) exposure (P  = 0.022, OR 2.863), carbapenems exposure (P  = 0.007, OR 3.831) and solid organ transplantation (P   <0.001, OR 19.454) were independent risk factors for a hospital-acquired CRKP BSI. Risk factors for a 28-day mortality from hospital-acquired KP BSI were CRKP BSI (P  =0.009, OR 5.562), septic shock (P  =0.002, OR 4.862), mechanical ventilation>96 hours (P =0.020, OR 8.765), and platelet counts <100×10⁹/L (P  =0.003, OR 4.464).

Conclusion

The incidence of hospital-acquired KP BSI continues to rise and the proportion of CRKP BSI is also increasing. We believe that the use of the BLBLIs needs to be carefully evaluated in hospital-acquired infection. Hospital-acquired KP BSI Patients with CRKP BSI, septic shock, mechanical ventilation and deficiency of platelets are more likely to have a poor prognosis.

TSST-1 protein exerts indirect effect on platelet activation and apoptosis

Thrombocytopenia or platelet dysfunction is a risk factor for severe infection. Staphylococcus aureus (S. aureus) releases a variety of virulence factors especially toxic shock syndrome toxin 1 (TSST-1), which may cause toxic shock syndrome. S. aureus, when carrying the tst gene, is more prone to cause toxic shock syndrome and is responsible for an especially high rate of mortality. However, the effect of TSST-1 protein on platelets is unknown. Patients with the tst gene positive S. aureus bacteremia showed more serious infection, higher mortality and lower platelet count. The tst gene positive S. aureus strains induce more platelet apoptosis and activation and corresponding up-regulation of Bak and down-regulation of Bcl-XL in addition to the activation of Caspase-3. C57BL/6 mice infected with the tst gene positive strains resulted in both a decrease in platelet count and an increase in platelet apoptosis and/or activation events and mortality. Moreover, TSST-1 protein, encoded by tst gene, caused the decrease of platelet count, the increase of platelet apoptosis and activation events and the level of inflammatory cytokines in vivo. However, TSST-1 protein was unable to induce traditional activation and apoptosis on human platelets in vitro. These results suggested that TSST-1 protein may exert indirect effects on platelet activation and apoptosis in vivo.

Hematological manifestations of COVID-19 acute respiratory distress syndrome patients and the impact of thrombocytopenia on disease outcomes: A retrospective study

Background:

Platelet count is a simple and readily available biomarker, in which thrombocytopenia was shown to be independently associated with disease severity and risk of mortality in the critical coronavirus disease-19 (COVID-19) patients. The aim of this study was to investigate the impact of thrombocytopenia on disease progression in critically ill COVID-19 patients with acute respiratory distress syndrome (ARDS) admitted to a medical intensive care unit (ICU).

Methods:

COVID-19-associated ARDS patients in our research hospitals’ ICU were retrospectively investigated. Patients were divided into two groups as thrombocytopenic (<150 × 10⁹/ml) patients on admission or those who developed thrombocytopenia during ICU follow-up (Group 1) and those without thrombocytopenia during ICU course and follow-up (Group 2).

Results:

The median platelet count of all patients was 240 × 10⁹/ml, and the median D-dimer was 1.16 mg/ml. On admission, 32 (18.3%) patients had thrombocytopenia. The mean platelet count of Group 1 was 100.0 ± 47.5 × 10⁹/ml. Group 1 was older and their Acute Physiology and Chronic Health Evaluation II and sequential organ failure assessment scores were higher. Group 1 had lower hemoglobin, neutrophil, and lymphocyte counts and higher ferritin and procalcitonin level. Invasive mechanical ventilation was more commonly needed, and disseminated intravascular coagulation (DIC) was more frequently observed in Group 1. The ICU and hospital length of stay of Group 1 was longer with higher mortality.

Conclusion:

Patients with thrombocytopenia had increased inflammatory markers, frequency of DIC, duration of ICU stay, and mortality. The presence of thrombocytopenia may reflect the progression of COVID-19 toward an unfavorable outcome.

Association Between Platelet Levels and 28-Day Mortality in Patients With Sepsis: A Retrospective Analysis of a Large Clinical Database MIMIC-IV

BACKGROUND

This research focused on evaluating the correlation between platelet count and sepsis prognosis, and even the dose-response relationship, in a cohort of American adults.

METHOD

Platelet counts were recorded retrospectively after hospitalization for patients admitted to Beth Israel Deaconess Medical Center's intensive care unit between 2008 and 2019. On admission to the intensive care unit, sepsis patients were divided into four categories based on platelet counts (very low < 50 × 10⁹/L, intermediate-low 50 × 10⁹-100 × 10⁹/L, low 100 × 10⁹-150 × 10⁹/L, and normal ≥ 150 × 10⁹/L). A multivariate Cox proportional risk model was used to calculate the 28-day risk of mortality in sepsis based on baseline platelet counts, and a two-piece linear regression model was used to calculate the threshold effect.

RESULTS

The risk of 28-day septic mortality was nearly 2-fold higher in the platelet very low group when compared to the low group (hazard ratios [HRs], 2.24; 95% confidence interval [CI], 1.92-2.6). Further analysis revealed a curvilinear association between platelets and the sepsis risk of death, with a saturation effect predicted at 100 × 10⁹/L. When platelet counts were below 100 × 10⁹/L, the risk of sepsis 28-day death decreased significantly with increasing platelet count levels (HR, 0.875; 95% CI, 0.84-0.90).

CONCLUSION

When platelet count was less than 100 × 10⁹/L, it was a strong predictor of the potential risk of sepsis death, which is declined by 13% for every 10 × 10⁹/L growth in platelets. When platelet counts reach up to 100 × 10⁹/L, the probability of dying to sepsis within 28 days climbs by 1% for every 10 × 10⁹/L increase in platelet count.

Administration of recombinant human thrombopoietin is associated with alleviated thrombocytopenia in adult intensive care unit patients with pneumonia: A single-center retrospective study

Background: Recombinant human thrombopoietin (rhTPO) is reported to stimulate platelet production and increase peripheral platelet counts; it is primarily used to manage chemotherapy-induced thrombocytopenia and idiopathic thrombocytopenic purpura. However, the effect of rhTPO in patients with pneumonia and thrombocytopenia remains uncertain. Objective: To assess the association of rhTPO and platelet counts in ICU patients with pneumonia and thrombocytopenia. Materials and Methods: A retrospective cohort study was performed in the ICU department, Nanfang Hospital, Southern Medical University, Guangzhou, China. From January 2016 to April 2021, patients with pneumonia and thrombocytopenia were allocated to two groups-the rhTPO and no-rhTPO groups-according to whether they received rhTPO treatment or not during their ICU stay. Demographical and clinical data were collected and analyzed using statistical software; p < 0.05 was considered statistically significant. Results: Out of 327 patients, 149 were in the rhTPO group and 178 were in the no-rhTPO group. Within the first 7 days, platelet counts increased more for patients in the rhTPO group compared with those in the no-rhTPO group (99.21 ± 102.613 vs. 2.08 ± 43.877, p = 0.000). The clinical recovery rate of platelets increased within 7 days (65.8 vs. 18.5%, p = 0.000) and, after 7 days of enrollment, hemorrhagic scores decreased more apparently in the rhTPO group (2.81 ± 2.856 vs. 1.16 ± 2.123, p = 0.000). Further, bleeding events ceased in 66.7% of the patients in the rhTPO group compared with 37.3% of the patients in the no-rhTPO group (p = 0.000). Less red-blood-cells transfusions were needed in the rhTPO group (3.639 ± 4.630 vs. 5.818 ± 6.858, p = 0.009). Furthermore, through logistic regression, rhTPO administration was found to be an independent indicator that affected the platelet recovery rate within 7 days. Conclusion: This study finds that rhTPO administration is associated with increased platelet counts, alleviated bleeding, and reduced blood transfusion. For patients with pneumonia and thrombocytopenia, rhTPO may be an effective therapeutic drug; however, more RCT trails are needed to confirm our observation.

Evolution of Platelet Activation Parameters During Septic Shock in Intensive Care Unit

During severe sepsis, platelet activation may induce disseminate microvascular thrombosis, which play a key role in critical organ failure. Crucially, most of the studies in this field have explored platelet-leukocyte interactions in animal models, or explored platelets under the spectrum of thrombocytopenia or disseminated intravascular coagulation and have not taken into account the complex interplay that might exist between platelets and leukocytes during human septic shock nor the kinetics of platelet activation. Here, we assessed platelet activation parameters at the admission of patients with sepsis to the intensive care unit (ICU) and 48 hours later. Twenty-two patients were enrolled in the study, thirteen (59.1%) of whom were thrombocytopenic. The control group was composed of twelve infection-free patients admitted during the study period. The activation parameters studied included platelet-leukocyte interactions, assessed by flow cytometry in whole blood, as well as membrane surface and soluble platelet activation markers measured by flow cytometry and dedicated ELISA kits. We also investigated platelet aggregation and secretion responses of patients with sepsis following stimulation, compared to controls. At admission, the level of circulating monocyte-platelet and neutrophil-platelet heterotypic aggregates was significantly higher in sepsis patients compared to controls and returned to a level comparable to controls or even below 48 hours later. Basal levels of CD62P and CD63 platelet membrane exposure at admission and 48 hours later were low and similar to controls. In contrast, plasma level of soluble GPVI and soluble CD40 ligand was significantly increased in septic patients, at the two times of analysis, reflecting previous platelet activation. Platelet aggregation and secretion responses induced by specific agonists were significantly decreased in septic conditions, particularly 48 hours after admission. Hence, we have observed for the first time that critically ill septic patients compared to controls have both an early and durable platelet activation while their circulating platelets are less responsive to different agonists.

Relationship Between Platelet to White Blood Cell Ratio and 30-Day Prognosis of Patients with Acute-on-Chronic Liver Failure

Background: Acute-on-chronic liver failure (ACLF) is always associated with thrombocytopenia or leukocytosis. Therefor the platelet to white blood cell ratio (PWR) in ACLF patients is always reduced. Objectives: Here, we assessed the relationship between PWR and prognosis in ACLF patients. Methods: A retrospective cohort of 415 patients, including 100 patients that were diagnosed of chronic hepatitis B, 104 patients suffered of HBV-related liver cirrhosis and 211 patients suffered of HBV-related ACLF, was investigated. Univariate and multivariate COX models were used to investigate the relationship between PWR and 30-day survival in patients with ACLF. Factors affecting PWR in ACLF patients were also analysed using logistic regression analysis. Results: At baseline, the platelet count in patients with HBV-related ACLF was significantly lower than that in patients with CHB and patients suffered of HBV-related cirrhosis. The PWR value was much higher in the survivors of ACLF than in ACLF patients who died. PWR, age, total bilirubine, prothrombin activity, and aspartate transaminase were independent predictors of the 30-day survival rate of ACLF patients. We also found that ascites and infection were independent factors related to the decrease of PWR in ACLF patients. Conclusions: The PWR value was significant declined in ACLF patients. And it was independent risk factors for the survival rate of those patients.

Platelets contribute to disease severity in COVID-19

OBJECTIVE

Heightened inflammation, dysregulated immunity, and thrombotic events are characteristic of hospitalized COVID-19 patients. Given that platelets are key regulators of thrombosis, inflammation, and immunity they represent prime candidates as mediators of COVID-19-associated pathogenesis. The objective of this study was to understand the contribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to the platelet phenotype via phenotypic (activation, aggregation) and transcriptomic characterization.

APPROACH AND RESULTS

In a cohort of 3915 hospitalized COVID-19 patients, we analyzed blood platelet indices collected at hospital admission. Following adjustment for demographics, clinical risk factors, medication, and biomarkers of inflammation and thrombosis, we find platelet count, size, and immaturity are associated with increased critical illness and all-cause mortality. Bone marrow, lung tissue, and blood from COVID-19 patients revealed the presence of SARS-CoV-2 virions in megakaryocytes and platelets. Characterization of COVID-19 platelets found them to be hyperreactive (increased aggregation, and expression of P-selectin and CD40) and to have a distinct transcriptomic profile characteristic of prothrombotic large and immature platelets. In vitro mechanistic studies highlight that the interaction of SARS-CoV-2 with megakaryocytes alters the platelet transcriptome, and its effects are distinct from the coronavirus responsible for the common cold (CoV-OC43).

CONCLUSIONS

Platelet count, size, and maturity associate with increased critical illness and all-cause mortality among hospitalized COVID-19 patients. Profiling tissues and blood from COVID-19 patients revealed that SARS-CoV-2 virions enter megakaryocytes and platelets and associate with alterations to the platelet transcriptome and activation profile.

The Relative Early Decrease in Platelet Count Is Associated With Mortality in Post-cardiotomy Patients Undergoing Venoarterial Extracorporeal Membrane Oxygenation

Background: The relationship between the magnitude of platelet count decrease and mortality in post-cardiotomy cardiogenic shock (PCS) patients undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) has not been well-reported. This study was designed to evaluate the association between the relative decrease in platelet count (RelΔplatelet) at day 1 from VA-ECMO initiation and in-hospital mortality in PCS patients.

Methods: Patients (n = 178) who received VA-ECMO for refractory PCS between January 2016 and December 2018 at the Beijing Anzhen Hospital were reviewed retrospectively. Multivariable logistic regression analyses were performed to assess the association between RelΔplatelet and in-hospital mortality.

Results: One hundred and sixteen patients (65%) were weaned from VA-ECMO, and 84 patients (47%) survived to hospital discharge. The median [interquartile range (IQR)] time on VA-ECMO support was 5 (3–6) days. The median (IQR) RelΔ platelet was 41% (26–59%). Patients with a RelΔ platelet ≥ 50% had an increased mortality compared to those with a RelΔ platelet < 50% (57 vs. 37%; p < 0.001). A large RelΔplatelet (≥50%) was independently associated with in-hospital mortality after controlling for potential confounders (OR 8.93; 95% CI 4.22–18.89; p < 0.001). The area under the receiver operating characteristic curve for RelΔ platelet was 0.78 (95% CI, 0.71–0.85), which was better than that of platelet count at day 1 (0.69; 95% CI, 0.61–0.77).

Conclusions: In patients receiving VA-ECMO for post-cardiotomy cardiogenic shock, a large relative decrease in platelet count in the first day after ECMO initiation is independently associated with an increased in-hospital mortality.

Accuracy of a modified 4Ts score in predicting heparin-induced thrombocytopenia in critically ill patients: A pilot study

PURPOSE

Thrombocytopenia is common among critically ill patients and heparin-induced thrombocytopenia (HIT) is often on the differential. Professional guidelines recommend calculating a pre-test probability score before performing HIT testing. The 4Ts score is widely utilized but accuracy has been questioned in critically ill patients. The HIT Expert Probability (HEP) score is available, but complexity limits use. Our objective was to compare a modified intensive care unit (ICU)-4Ts score to available scoring tools.

MATERIALS AND METHODS

This was a single-center retrospective pilot study. Adult ICU patients that were tested for HIT and had a documented 4Ts score were included. A blinded investigator retrospectively calculated the HEP and ICU-4Ts score. Receiver operating characteristics (ROC) area under the curve (AUC), sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were compared.

RESULTS

In 194 included patients, ROC AUC was significantly higher for the ICU-4Ts compared to the 4Ts score (0.80 versus 0.66, respectively; p = 0.044). The ICU-4Ts score had the highest specificity, PPV, and NPV. The sensitivity was similar between the HEP and ICU-4Ts score.

CONCLUSIONS

The ICU-4Ts score better predicted the diagnosis of HIT compared to the 4Ts score. Prospective validation studies are needed to confirm these results.