Thrombocytopenia in the critically ill: prevalence, incidence, risk factors, and clinical outcomes

Thrombocytopenia developed in intensive care unit for congenital heart disease: incidence, risk factors, and outcomes

BACKGROUND

Thrombocytopenia is common for patients in the intensive care unit (ICU) and is associated with adverse outcomes. ICU thrombocytopenia in pediatric patients who underwent cardiac surgeries with cardiopulmonary bypass (CPB) is inadequately studied.

OBJECTIVES

We aimed to investigate the incidence, risk factors, and prognostic role of ICU thrombocytopenia after congenital cardiac surgeries with CPB.

METHODS

A retrospective study involving 11 761 patients was conducted. Patients were categorized into 4 groups of thrombocytopenia based on platelet counts tested during ICU: non (>150 × 109/L), mild (100-150 × 109/L), moderate (50-100 × 109/L), and severe (<50 × 109/L). Logistic and Cox regression analyses were utilized to explore the risk factors of thrombocytopenia and the association of ICU thrombocytopenia with 30-day mortality.

RESULTS

ICU thrombocytopenia was observed in 4007 patients (34.1%), with mild, moderate, and severe thrombocytopenia occurring in 2773 (23.6%), 987 (8.4%), and 247 (2.1%) patients, respectively. Younger age, cyanotic congenital heart disease, CPB duration, and preoperative laboratory findings (red blood cell, thrombocytopenia, red cell distribution width, hematocrit, and coagulation disorder) were identified as independent risk factors of ICU thrombocytopenia. Patients with moderate (hazard ratio [95% CI]: 11.38 [3.02-42.87]; P < .001) and severe thrombocytopenia (hazard ratio [95% CI]: 49.54 [13.11-187.14]; P < .001) had a significantly higher risk of 30-day mortality. Furthermore, with the increase in the severity of ICU thrombocytopenia, there was an incremental increase in the incidence of postoperative critical bleeding and thrombosis, perioperative blood transfusions, length of ICU stays, and duration of mechanical ventilation.

CONCLUSION

ICU thrombocytopenia occurred in one-third of children after congenital cardiac surgery with CPB, and it was associated with multiple adverse outcomes.

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.

Lower platelet count and metastatic tumor are associated with increased risk of spontaneous bleeding in critically ill patients with cancer: An observational study

BACKGROUND

Thrombocytopenia is common in critically ill patients with cancer. However, the association of platelet count with spontaneous bleeding is controversial in critically ill patients and the association with cancer-related characteristics is unknown.

METHODS

This observational study includes patients with active cancer and severe thrombocytopenia. A logistic regression model adjusted for confounders was used to evaluate the association of daily platelet count and cancer-related characteristics (type of cancer and presence of metastasis) with spontaneous bleeding. Confounders were identified using directed acyclic graphs.

RESULTS

We screened 5822 patients, 255 (4.4%) met eligibility criteria resulting in 1401 daily observations. Fifty-three patients (20.8%) had spontaneous bleeding during the intensive care unit stay, 64% presenting minor, and 36% major bleeding. The adjusted odds ratio (OR) for spontaneous bleeding with platelet count between 49 and 20 × 109 /L was 4.6 (1.1-19.6), with platelet count between 19 and 10 × 109 /L was 14.2 (3.1-66.2), and with platelet count below 10 × 109 /L was 39.6 (6.9-228.5). The adjusted OR for spontaneous bleeding in patients with hematologic malignancies was 0.6 (0.4-1.2), and 4.3 (2.0-9.0) for patients with metastatic tumor.

CONCLUSIONS

In critically ill patients with active cancer and severe thrombocytopenia, lower counts of platelets and presence of metastasis are associated with increased risk of spontaneous bleeding, while hematologic malignancy is not associated with increased risk of spontaneous bleeding.

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.

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.

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.

RISK OF HOSPITAL MORTALITY IN CRITICALLY ILL PATIENTS WITH TRANSIENT AND PERSISTENT THROMBOCYTOPENIA: A RETROSPECTIVE STUDY

ABSTRACT

Background: Thrombocytopenia (TP), a common occurrence among patients admitted to the intensive care unit (ICU), is significantly associated with prolonged ventilator use, prolonged ICU stay, and increased mortality. The duration of TP serves as an indicator of patient outcome, although the exact duration of TP associated with poor patient outcome remains unclear. In this study, the data of 3,291 patients on their first admission to the ICU between January 2010 and December 2020 were retrospectively analyzed. Participants were divided into the no TP, TP 1-2 days, TP 3-6 days, and TP ≥7 days groups based on the duration of TP. External validation was performed using the Medical Information Mart for Intensive Care III data set. Results: A longer duration of TP was significantly associated with high volume of transfusion and high hospital mortality ( P < 0.01), and 37.3% of the participants developed TP during their ICU stay. The results of Kaplan-Meier survival analysis and Cox regression analysis after excluding the effects of patients who died shortly after ICU admission revealed the absence of significant differences between the no TP and TP 1-2 days groups ( P > 0.05). However, when the duration of TP exceeded 2 days, patient mortality increased with an increase in the duration of TP ( P < 0.01). Similar findings were obtained with the Medical Information Mart for Intensive Care III data set. Conclusions: The duration of TP in critically ill patients is positively correlated with poor patient outcome. We classified TP as either transient TP or persistent TP based on a cutoff duration of 2 days. Monitoring the duration of TP may aid in the prediction of patients' outcome in the ICU.

Association of longitudinal platelet count trajectory with ICU mortality: A multi-cohort study

Objective

Platelet (PLT) engages in immune and inflammatory responses, all of which are related to the prognosis of critically ill patients. Although thrombocytopenia at ICU admission contributes to in-hospital mortality, PLT is repeatedly measured during ICU hospitalization and the role of longitudinal PLT trajectory remains unclear. We aimed to identify dynamic PLT trajectory patterns and evaluate their relationships with mortality risk and thrombocytopenia.

Methods

We adopted a three-phase, multi-cohort study strategy. Firstly, longitudinal PLT trajectory patterns within the first four ICU days and their associations with 28-day survival were tested in the eICU Collaborative Research Database (eICU-CRD) and independently validated in the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Secondly, the relationships among PLT trajectory patterns, thrombocytopenia, and 28-day mortality were explored and validated. Finally, a Mortality GRade system for ICU dynamically monitoring patients (Mortality-GRID) was developed to quantify the mortality risk based on longitudinal PLT, which was further validated in the Molecular Epidemiology of Acute Respiratory Distress Syndrome (MEARDS) cohort.

Results

A total of 35,332 ICU patients were included from three cohorts. Trajectory analysis clustered patients into ascending (AS), stable (ST), or descending (DS) PLT patterns. DS patients with high baseline PLT decline quickly, resulting in poor prognosis. AS patients have low baseline PLT but recover quickly, favoring a better prognosis. ST patients maintain low PLT, having a moderate prognosis in between (HRSTvsAS = 1.26, 95% CI: 1.14–1.38, P = 6.15 × 10−6; HRDSvsAS = 1.58, 95% CI: 1.40–1.79, P = 1.41 × 10−13). The associations remained significant in patients without thrombocytopenia during the entire ICU hospitalization and were robust in sensitivity analyses and stratification analyses. Further, the trajectory pattern was a warning sign of thrombocytopenia, which mediated 27.2% of the effects of the PLT trajectory on 28-day mortality (HRindirect = 1.11, 95% CI: 1.06–1.17, P = 9.80 × 10−6). Mortality-GRID well predicts mortality risk, which is in high consistency with that directly estimated in MEARDS (r = 0.98, P = 1.30 × 10−23).

Conclusion

Longitudinal PLT trajectory is a complementary predictor to baseline PLT for patient survival, even in patients without risk of thrombocytopenia. Mortality-GRID could identify patients at high mortality risk.

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.

Hirsutine, a novel megakaryopoiesis inducer, promotes thrombopoiesis via MEK/ERK/FOG1/TAL1 signaling

BACKGROUND

Thrombocytopenia (TP) remains a challenge in clinical hematology. TP may have serious consequences, such as recurrent skin and mucosal bleeding and increased risk of intracranial and internal organ hemorrhage. However, effective and safe therapeutic drugs for the long-term management of TP are still lacking.

PURPOSE

This study aimed to identify more effective active compounds for TP therapy.

METHODS

Liquid chromatography-mass spectrometry-nuclear magnetic resonance analysis was used to confirm the medicinal species and chemical structure of Hirsutine (HS). The proliferation of HS was examined by Cell Counting Kit (CCK-8) assay on cells lines. The effect of HS on megakaryocyte differentiation was analyzed by evaluating the expression of CD41, CD42b, and DNA ploidy via flow cytometry (FCM). The morphology of megakaryocytes and intermediate cells was observed using an optical microscope. K562 cells were then stained with Giemsa and benzidine. qRT-PCR was used to examine the mRNA expression of GATA-1, GATA-2, FOG-1, TAL-1, RUNX-1, NF-E2, and KLF-1 in K562 cells. Protein levels of the transcription factors were analyzed by western blotting. An MEK inhibitor was used to verify the relationship between the MEK/ERK signaling pathway and CD41/CD42b (FCM), FOG-1, and TAL-1. The Kunming thrombocytopenia mouse model was established by X-ray irradiation (4 Gy) and used to test HS activity and related hematopoietic organ index in vivo. Finally, computer simulations of molecular docking were used to predict the binding energies between HS-MEK and HS-ERK.

RESULTS

We preliminarily identified HS by screening a plant-sourced compound library for natural compounds with megakaryocytic differentiation and maturation (MKD/MKM)-promoting activity. We found that HS not only enhanced MKD/MKM of K562 and Meg01 cells, but also suppressed the decline of peripheral platelet levels in X-ray-induced myelosuppressive mice. In addition, HS promoted MKD via activation of MEK-ERK-FOG1/TAL1 signaling, which may be the key molecular mechanism of HS action in TP treatment. Molecular docking simulations further verified that HS targets the signaling protein MEK with high-affinity.

CONCLUSION

In this study, we report for the first time that hirsutine boosts MKD/MKM through the MEK/ERK/FOG1/TAL1 signaling pathway and thus represents a promising treatment option for TP.

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.

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.

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.

Association Between Postoperative Thrombocytopenia and Outcomes After Coronary Artery Bypass Grafting Surgery

Objectives: The effect of postoperative thrombocytopenia on adverse events among coronary artery bypass graft (CABG) patients remains unclear. This study aims to investigate the association between postoperative thrombocytopenia and perioperative outcomes of CABG. Methods: This is a retrospective study with MIMIC-III (Medical Information Mart for Intensive Care III) database. Adult patients who underwent CABG were included to analyze the impact of thrombocytopenia in patients' outcomes. Postoperative thrombocytopenia was defined as a platelet count <100 × 109/L on the first day after CABG surgery. A multivariable logistic regression analysis was utilized to adjust the effect of thrombocytopenia on outcomes for baseline and covariates, and to determine the association with outcomes. Results: A total of 4,915 patients were included, and postoperative thrombocytopenia occurred in 696 (14.2%) patients. Postoperative thrombocytopenia was not associated with increased 28-day mortality (OR 0.75; 95% CI 0.33-1.72; P = 0.496) or in-hospital mortality (OR 0.75; 95% CI 0.34-1.63; P = 0.463) after adjusting for confounders. Regarding the secondary outcomes, it was associated with a higher risk of a prolonged stay in the intensive care unit (OR 1.53; 95% CI 1.18-1.97; P = 0.001), prolonged hospital stays (OR 1.58; 95% CI 1.21-2.06; P = 0.001), prolonged mechanical ventilation time (OR 1.67; 95% CI 1.14-2.44; P = 0.009), and a trend toward increased occurrence of massive bleeding (OR 1.41; 95% CI 1.00-2.01; P = 0.054). There was no significant association between an increased risk of prolonged vasopressor use and the continuous renal replacement therapy rate. Conclusions: Postoperative thrombocytopenia was associated with prolonged ICU and hospital stays but not with increased perioperative mortality among CABG patients.

Using Machine Learning Algorithms to Predict Hospital Acquired Thrombocytopenia after Operation in the Intensive Care Unit: A Retrospective Cohort Study

Hospital acquired thrombocytopenia (HAT) is a common hematological complication after surgery. This research aimed to develop and compare the performance of seven machine learning (ML) algorithms for predicting patients that are at risk of HAT after surgery. We conducted a retrospective cohort study which enrolled adult patients transferred to the intensive care unit (ICU) after surgery in West China Hospital of Sichuan University from January 2016 to December 2018. All subjects were randomly divided into a derivation set (70%) and test set (30%). ten-fold cross-validation was used to estimate the hyperparameters of ML algorithms during the training process in the derivation set. After ML models were developed, the sensitivity, specificity, area under the curve (AUC), and net benefit (decision analysis curve, DCA) were calculated to evaluate the performances of ML models in the test set. A total of 10,369 patients were included and in 1354 (13.1%) HAT occurred. The AUC of all seven ML models exceeded 0.7, the two highest were Gradient Boosting (GB) (0.834, 0.814-0.853, p < 0.001) and Random Forest (RF) (0.828, 0.807-0.848, p < 0.001). There was no difference between GB and RF (0.834 vs. 0.828, p = 0.293); however, these two were better than the remaining five models (p < 0.001). The DCA revealed that all ML models had high net benefits with a threshold probability approximately less than 0.6. In conclusion, we found that ML models constructed by multiple preoperative variables can predict HAT in patients transferred to ICU after surgery, which can improve risk stratification and guide management in clinical practice.

Association of thrombocytopenia and infection in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

Background

The impact of thrombocytopenia on infection in patients with ST-elevation myocardial infarction (STEMI) remains poorly understood.

Aims

To evaluate the association between thrombocytopenia and infection in patients with STEMI.

Methods

Patients diagnosed with STEMI were identified from January 2010 to June 2016. The primary endpoint was in-hospital infection, and major adverse clinical events (MACE) and all-cause death were considered as secondary endpoints.

Results

A total of 1401 STEMI patients were enrolled and divided into two groups according to the presence (n = 186) or absence (n = 1215) of thrombocytopenia. The prevalence of in-hospital infection was significantly higher in the thrombocytopenic group (30.6% (57/186) vs. 16.2% (197/1215), p < 0.001). Prevalence of in-hospital MACE (30.1% (56/186) vs. 16.4% (199/1215), p < 0.001) and all-cause death (8.1% (15/186) vs. 3.8% (46/1215), p = 0.008) revealed an increasing trend. Multivariate analysis indicated that thrombocytopenia was independently associated with increased in-hospital infection (OR, 2.09; 95%CI 1.32–3.27; p = 0.001) and MACE (1.92; 1.27–2.87; p = 0.002), but not all-cause death (1.87; 0.88–3.78; p = 0.091). After a median follow-up of 2.85 years, thrombocytopenia was not associated with all-cause death at multivariable analysis (adjusted hazard ratio, 1.19; 95%CI 0.80–1.77; p = 0.383).

Conclusions

Thrombocytopenia is significantly correlated with in-hospital infection and MACE, and might be used as a prognostic tool in patients with STEMI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02210-3.

A 12-year study evaluating the outcomes and predictors of mortality in critically ill cancer patients admitted with septic shock

Background

Though sepsis is common in patients with cancer, there are limited studies that evaluated sepsis and septic shock in this patient population. The objective of this study was to evaluate the outcomes and to identify predictors of mortality in cancer patients admitted to the intensive care unit (ICU) with septic shock.

Methods

This was a retrospective study conducted at a medical-surgical oncologic ICU of a comprehensive cancer center. Adult cancer patients admitted with septic shock between January 1, 2008 and December 31, 2019 were enrolled. Septic shock was defined as an ICU admission diagnosis of sepsis that required initiating vasopressors within 24 h of admission. Patient baseline characteristics, ICU length of stay and ICU and hospital mortality were recorded. Univariate analysis and logistic regression were performed to identify predictors associated with ICU and hospital mortality.

Results

During the study period, 1408 patients met the inclusion criteria. The mean age was 56.8 ± 16.1 (SD) years and mean Acute Physiology and Chronic Health Evaluation (APACHE) II was 23.0 ± 7.91 (SD). Among the enrolled patients, 67.8% had solid tumors while the remaining had hematological malignancies. Neutropenia and thrombocytopenia were reported in 19.3 and 39.5% of the patients, respectively, and mechanical ventilation was required for 42% of the patients. Positive cultures were reported in 836 (59.4%) patients, most commonly blood (33%) and respiratory (26.6%). Upon admission, about half the patients had acute kidney injury, while elevated total bilirubin and lactic acid levels were reported in 13.8 and 65.2% of the patients, respectively. The median ICU length of stay was 4 days (IQR 3–8), and ICU and hospital mortality were reported in 688 (48.9%) and 914 (64.9%) patients, respectively. Mechanical ventilation, APACHE II, thrombocytopenia, positive cultures, elevated bilirubin and lactic acid levels were significantly associated with both ICU and hospital mortality.

Conclusions

In a relatively large cohort of patients with solid and hematological malignancies admitted to the ICU with septic shock, hospital mortality was reported in about two-third of the patients. Mechanical ventilation, APACHE II, thrombocytopenia, positive cultures, elevated bilirubin and lactic acid levels were significant predictors of mortality.

Coagulopathy and its associated factors among patients with a bleeding diathesis at the University of Gondar Specialized Referral Hospital, Northwest Ethiopia

Background

Coagulopathy is the major cause of mortality and morbidity throughout the world. Globally, about 26–45% of healthy people have a history of bleeding symptoms, which may be a result of thrombocytopenia, factor deficiency, or pathological inhibitory.

Objective

To assess coagulopathy and its associated factors among patients with bleeding diathesis at the University of Gondar Specialized Referral Hospital from January to May 2020.

Method

A cross-sectional study was conducted on 384 study participants with bleeding diathesis recruited by using a convenient sampling technique. Socio-demographic and clinical characteristics were collected by using questioners. Then 6 ml venous blood was collected with a needle and syringe method. About 3 ml blood was transferred to EDTA test tube for platelet count and 2.7 ml blood was transferred to a test tube containing 0.3 ml of 3.2% sodium citrated anticoagulant for coagulation test. For those study participants with prolonged coagulation tests, a mixing test was done. Blood film and stool examination were also done for malaria and intestinal parasite identification, respectively. The data were entered into EPI-Info version 3.5.3 and then transferred to SPSS version-20 for analysis. Descriptive statistics were summarized as percentages, means, and standard deviations. Bivariate and multivariate logistic regression was used to identify the associated factors, and a P-value less than 0.05 was considered statistically significant.

Results

In this study, the prevalence of coagulopathy was 253/384 (65.9%; 95% CI: 61.16, 70.64). From them, 21.3% (54/253), 51.4% (130/253), and 27.3% (69/253) had only thrombocytopenia, only prolonged coagulation test, and mixed abnormality, respectively. Among participants with prolonged coagulation time, the prevalence of factor deficiency was 21.1% (42/199). Cardiac disease (AOR = 4.80; 95% CI: 2.65, 23.1), and other chronic diseases (AOR = 8.1; 95% CI: 1.84, 35.58) were significantly associated with coagulopathy.

Conclusion

In this study, coagulopathy due to inhibitory was a public health problem. The participants with cardiac and other chronic diseases were at high risk for coagulopathy. Therefore, mixing tests could be done for all prolonged coagulation tests and it could be considered as a routine laboratory test.

Frequency of Thrombocytopenia and Heparin-Induced Thrombocytopenia in Patients Receiving Extracorporeal Membrane Oxygenation Compared With Cardiopulmonary Bypass and the Limited Sensitivity of Pretest Probability Score

OBJECTIVES

To ascertain: 1) the frequency of thrombocytopenia and heparin-induced thrombocytopenia; 2) positive predictive value of the Pretest Probability Score in identifying heparin-induced thrombocytopenia; and 3) clinical outcome of heparin-induced thrombocytopenia in adult patients receiving venovenous- or venoarterial-extracorporeal membrane oxygenation, compared with cardiopulmonary bypass.

DESIGN

A single-center, retrospective, observational cohort study from January 2016 to April 2018.

SETTING

Tertiary referral center for cardiac and respiratory failure.

PATIENTS

Patients who received extracorporeal membrane oxygenation for more than 48 hours or had cardiopulmonary bypass during specified period.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical and laboratory data were collected retrospectively. Pretest Probability Score and heparin-induced thrombocytopenia testing results were collected prospectively. Mean age (± SD) of the extracorporeal membrane oxygenation and cardiopulmonary bypass cohorts was 45.4 (± 15.6) and 64.9 (± 13), respectively (p < 0.00001). Median duration of cardiopulmonary bypass was 4.6 hours (2-16.5 hr) compared with 170.4 hours (70-1,008 hr) on extracorporeal membrane oxygenation. Moderate and severe thrombocytopenia were more common in extracorporeal membrane oxygenation compared with cardiopulmonary bypass throughout (p < 0.0001). Thrombocytopenia increased in cardiopulmonary bypass patients on day 2 but was normal in 83% compared with 42.3% of extracorporeal membrane oxygenation patients at day 10. Patients on extracorporeal membrane oxygenation also followed a similar pattern of platelet recovery following cessation of extracorporeal membrane oxygenation. The frequency of heparin-induced thrombocytopenia in extracorporeal membrane oxygenation and cardiopulmonary bypass were 6.4% (19/298) and 0.6% (18/2,998), respectively (p < 0.0001). There was no difference in prevalence of heparin-induced thrombocytopenia in patients on venovenous-extracorporeal membrane oxygenation (8/156, 5.1%) versus venoarterial-extracorporeal membrane oxygenation (11/142, 7.7%) (p = 0.47). The positive predictive value of the Pretest Probability Score in identifying heparin-induced thrombocytopenia in patients post cardiopulmonary bypass and on extracorporeal membrane oxygenation was 56.25% (18/32) and 25% (15/60), respectively. Mortality was not different with (6/19, 31.6%) or without (89/279, 32.2%) heparin-induced thrombocytopenia in patients on extracorporeal membrane oxygenation (p = 0.79).

CONCLUSIONS

Thrombocytopenia is already common at extracorporeal membrane oxygenation initiation. Heparin-induced thrombocytopenia is more frequent in both venovenous- and venoarterial-extracorporeal membrane oxygenation compared with cardiopulmonary bypass. Positive predictive value of Pretest Probability Score in identifying heparin-induced thrombocytopenia was lower in extracorporeal membrane oxygenation patients. Heparin-induced thrombocytopenia had no effect on mortality.

Clinical and Laboratory Predictors of Severity, Criticality, and Mortality in COVID-19: A Multisystem Disease

Coronavirus disease 2019 (COVID-19) pandemic continues devastating effects on healthcare systems. Such a crisis calls for an urgent need to develop a risk stratification tool. The present chapter aimed to identify laboratory and clinical correlates of adverse outcomes in patients with COVID-19. To this end, we conducted a systematic evaluation of studies that investigated laboratory abnormalities in patients with COVID-19 and compared i. patients with a severe form of disease and patients with a non-severe form of the disease, ii. patients who were in critical condition and patients who were not in critical condition, and iii. patients who survived and patients who died. We included 54 studies in the data synthesis. Compared to patients with a non-severe form of COVID-19, patients who had a severe form of disease revealed higher values for white blood cells (WBC), polymorphonuclear leukocytes (PMN), total bilirubin, alanine aminotransferase (ALT), creatinine, troponin, procalcitonin, lactate dehydrogenase (LDH), and D-dimer. By contrast, platelet count, lymphocyte count, and albumin levels were decreased in patients with a severe form of COVID-19. Also, patients with a severe phenotype of disease were more likely to have diabetes, chronic heart disease, chronic obstructive pulmonary disease (COPD), cerebrovascular disease, hypertension, chronic kidney disease (CKD), and malignancy. Compared to patients who survived, patients who died had higher WBC, PMN, total bilirubin, ALT, procalcitonin, IL-6, creatinine, PT, lymphocyte count, platelet count, and albumin. Also, non-survivors revealed a higher prevalence of diabetes, chronic heart disease, COPD, cerebrovascular disease, and CKD. Meta-analyses identified several laboratory parameters that might help the prediction of severe, critical, and lethal phenotypes of COVID-19. These parameters correlate with the immune system function, inflammation, coagulation, and liver and kidney function.

Platelet count patterns and patient outcomes in sepsis at a tertiary care center: Beyond the APACHE score

Acute physiology and chronic health evaluation II (APACHE-II) scoring system is used to classify disease severity of patients in the intensive care unit. However, several limitations render the scoring system inadequate in identifying risk factors associated with outcomes. Little is known about the association of platelet count patterns, and the timing of platelet count and other hematologic parameters in predicting mortality in patients with sepsis.This retrospective observational study included 205 septic shock patients, with an overall mortality of 47.8%, enrolled at a tertiary care hospital in Riyadh, Kingdom of Saudi Arabia between 2018 and 2020. Bivariate and multivariate regression analyses were used to identify hematologic risk factors associated with mortality. We used the bivariate Pearson Correlation test to determine correlations between the tested variables and APACHE-II score.Two platelet count patterns emerged: patients with a decline in platelet count after admission (group A pattern, 93.7%) and those with their lowest platelet count at admission (group B pattern, 6.3%). The lowest mean platelet count was significantly lower in nonsurvivors (105.62 ± 10.67 × 103/μL) than in survivors (185.52 ± 10.81 × 103/μL), P < .001. Bivariate Pearson correlation revealed that the lowest platelet count and platelet count decline were significantly correlated with APACHE-II score (r = -0.250, P < .01), (r = 0.326, P < .001), respectively. In multiple logistic regression analysis, the independent mortality risk factors were degree of platelet count decline in group A (odds ratio, 1.028 [95% confidence interval: 1.012-1.045], P = .001) and platelet pattern in group B (odds ratio, 6.901 [95% confidence interval: 1.446-32.932], P = .015). The patterns, values, subsets, and ratios of white blood cell count were not significantly associated with mortality.Nadir platelet count and timing, and degree of platelet count decline are useful markers to predict mortality in early septic shock. Therefore, platelet count patterns might enhance the performance of severity scoring systems in the intensive care unit.

Ex Vivo Manufacture of Megakaryocytes and Platelets from Stem Cells: Recent Advances Toward Transfusion in Humans

The generation of ex vivo functional megakaryocytes (MK) and platelets is an important issue in transfusion medicine as donor dependence implies in limitations, such as shortage of eligible volunteers. Indeed, platelet transfusion is still a procedure that saves the lives of patients with defective platelet production. Recent technological development has enabled the isolation and expansion of stem cells that can be used as a source for the production of functional platelets for transfusion. In this review, we discuss recent approaches of in vitro or ex vivo production of MK and platelets, suggesting that, in the near future, donor-independent sources may become a possibility. The feasibility of using these cells in the clinic may be safer, and in vitro manipulation could generate universally compatible products, solving problems related to platelet refractoriness. However, functionality and survival testing of these products in human beings are scarce; therefore, additional studies are needed to consolidate this purpose.

The Novel Coronavirus and Haemostatic Abnormalities: Pathophysiology, Clinical Manifestations, and Treatment Recommendations

The COVID-19 pandemic, caused by the SARS-C0V-2 virus, was initially considered and managed in a similar manner to the previous SARS epidemic as they are both caused by coronaviruses. What has now become apparent is that a major cause of morbidity and mortality in COVID-19 is abnormal thrombosis. This thrombosis occurs on a macro- and microvascular level and is unique to this disease. The virus has been demonstrated in the endothelium of the pulmonary alveoli and as such is thought to contribute to the devastating respiratory complications encountered. D-dimer concentrations are frequently raised in COVID to levels not frequently seen previously. The optimal anticoagulation treatment in COVID remains to be determined, and the myriad of pathophysiologic effects caused by this virus in the human host have also yet to be fully elucidated.

Thrombocytopenia in intensive care unit patients: A scoping review

BACKGROUND

Thrombocytopenia is frequent in intensive care unit (ICU) patients and may be associated with adverse outcomes. We aimed to assess the incidence, risk factors, and outcomes associated with thrombocytopenia in adult ICU patients.

METHODS

We conducted a scoping review in accordance with the Preferred Reporting Items for Systematic Review and Meta-analyses extension for Scoping Reviews (PRISMA-ScR) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We included study reports on adult ICU patients with thrombocytopenia and assessed patient-important outcomes, including mortality and health-related quality-of-life.

RESULTS

We included a total of 70 studies comprising a total of 215 098 patients; 57 were cohort studies. The incidence of thrombocytopenia varied from 8 to 56 per 100 admissions (very low quality of evidence). We identified several risk factors including age, sepsis, and higher disease severity (low quality of evidence). Thrombocytopenia was associated with bleeding, use of life support, length of stay in the ICU, and increased mortality (low/very low quality of evidence). Data on platelet transfusion before invasive procedures and transfusion thresholds were limited. No studies assessed the benefits and harms of thromboprophylaxis in ICU patients with thrombocytopenia.

CONCLUSIONS

Thrombocytopenia is common and associated with increased morbidity and mortality in adult ICU patients. Several risk factors for thrombocytopenia exists, but the evidence-base on management strategies, including transfusion thresholds and thromboprophylaxis in ICU patients is very limited.

Thrombocytopenia in 737 adult intensive care unit patients: A real-world study of associated factors, drugs, platelet transfusion, and clinical outcome

Objective:

We aimed to identify and represent factors associated with thrombocytopenia in intensive care unit, especially the pathogens and drugs related to severe and extremely thrombocytopenia. Then, we aim to compare the mortality of platelet transfusion and non-transfusion in patients with different degrees of thrombocytopenia.

Methods:

We identified all thrombocytopenic patients in intensive care unit by using platelet-specific values and then extracted electronic health records from our Hospital Information System. Data were statistically analyzed with t test, chi-square test, and logistic regression.

Results:

We found that infections (32.7%) were the most frequent cause associated with thrombocytopenia, followed by sepsis shock (3.93%) and blood loss (2.99%). Meanwhile, antifungals (p = 0.002) and bacterial infection (p = 0.037) were associated with severe and extremely severe thrombocytopenia. Finally, we found that the mortality of platelet transfusion and non-transfusion in patients was statistically significant for patients with platelet counts between 30 and 49/nL (χ² = 9.719, p = 0.002).

Conclusion:

Infection and sepsis emerged as two primary factors associated with thrombocytopenia in intensive care unit. Meanwhile, antifungals and bacterial infection were associated with platelet counts less than 49/nL. Finally, platelet transfusion may be associated with reduced mortality in patients with platelet counts between 30 and 49/nL.

Prognostic risk factors for respiratory failure after esophagectomy

Background

Esophagectomy is a high-risk surgical procedure with significant postoperative morbidity and mortality. Respiratory failure is one of the most common complications after esophageal cancer surgery. The purpose of this study was to explore risk factors that affect the recovery of respiratory failure in this kind of patients.

Methods

Totally 2,360 patients underwent esophagectomies with cervical anastomosis or intrathoracic anastomosis in our center from January 2012 to December 2017. Among them, 130 patients with respiratory failure requiring mechanical ventilation were included in the study. The Spearman’s rank correlation test and Mann-Whitney U test were performed to identify the influential factors for the duration of mechanical ventilation.

Results

Most patients (81.5%) in this study recovered in the first two weeks of mechanical ventilation, the average duration of mechanical ventilation was 10.1 days. Statistical analysis indicated that lung function test parameters such as FEV₁/FVC ratio and RV/TLC ratio could have significant influence on the duration of mechanical ventilation. The abnormally increased FEV₁/FVC ratio and RV/TLC ratio could obviously prolong the ventilation duration. Old age, thrombocytopenia, the elevated creatinine, C-reactive protein (CRP) and lactate could also significantly lengthen the duration of mechanical ventilation.

Conclusions

Abnormally increased FEV₁/FVC ratio and RV/TLC ratio as well as old age, thrombocytopenia, elevated creatinine, CRP and blood lactate were found to be risk factors for the recovery of patients with respiratory failure after esophagectomies.

Etiologies of Thrombocytopenia in the Community Hospital: The Experience of 1 Hematologist

BACKGROUND

Thrombocytopenia in hospitalized patients is a common cause for hematologic consultation. Our experience in the community hospital setting can inform treating physicians of the causes for and need to treat thrombocytopenia. Here we describe our clinical experience from 2 community hospitals over a 22-month period, wherein a single hematologist was consulted for 97 cases of thrombocytopenia in 93 patients.

METHODS

Referred patients underwent history, physical, review of old records and imaging, relevant laboratory testing, review of the peripheral smear, and a bone marrow aspirate and biopsy if clinically indicated.

RESULTS

Thirty-five patients had a primary hematologic cause for their thrombocytopenia. Fifty-one had secondary causes for thrombocytopenia. Eleven patients had no discernible etiology for their thrombocytopenia. The most common hematologic diagnoses were immune thrombocytopenia purpura (n = 12), heparin-induced thrombocytopenia (n = 6), in vitro platelet clumping (n = 4), quite remarkably acute progranulocytic leukemia (n = 4), and thrombotic thrombocytopenia purpura (n = 3). The latter 3 were immediately diagnosed by reviewing the peripheral smear, which led to appropriate therapy. The most common nonhematologic etiologies were liver disease (n = 21), bacterial sepsis (n = 12), and oral medication (n = 7). Although the thrombocytopenia was mostly nonacute, immediate hematologic interventions were needed for 21 patients. Four patients died, none from complications of thrombocytopenia.

CONCLUSIONS

Thrombocytopenia in hospitalized patients requires consideration of multiple etiologies and review of the peripheral smear. Liver disease is often overlooked as a cause for thrombocytopenia.

Coagulation tests on admission correlate with mortality and morbidity in general ICU patients: An observational study

BACKGROUND

It is well known that low platelet count on admission to intensive care units (ICU) is associated with increased mortality. However, it is unknown whether prothrombin time (PT-INR) and activated partial thromboplastin time (APTT) on admission correlate with mortality and organ failure. Therefore, the aim of this study was to investigate whether PT-INR and APTT at admission can predict outcome in the critically ill patient after adjusting for severity of illness measured with Simplified Acute Physiology Score 3 (SAPS 3).

MATERIALS AND METHODS

Data were retrospectively collected. APTT and PT-INR taken on admission and SAPS 3 score were independent variables in all regression analyses. Survival analysis was done with Cox regression. Organ failure was reported as days alive and free (DAF) of vasopressors and invasive ventilation, need of continuous renal replacement therapy (CRRT) and Acute Kidney Injury Network creatinine score (AKIN-crea).

RESULTS

A total of 3585 ICU patients were included. Prolonged APTT correlated with mortality with 95% confidence interval (CI) of hazard ratio 1.001-1.010. Prolonged APTT also correlated with DAF vasopressor, CRRT and AKIN-crea with 95% CI of odds ratio (OR) 1.009-1.034, 1.016-1.037 and 1.009-1.028, respectively. Increased PT-INR correlated with DAF vasopressor and DAF ventilator with 95% CI of OR 1.112-2.014 and 1.135-1.847, respectively.

CONCLUSIONS

Activated partial thromboplastin time prolongation was associated with mortality and all morbidity outcomes except the DAF ventilator. PT-INR increase at admission was associated with DAF vasopressor and DAF ventilator. APTT and PT-INR at admission correlate with morbidity, which is not accounted for in the SAPS 3 model.

A systematic literature review on the use of platelet transfusions in patients with thrombocytopenia

Objective: Investigate globally, current treatment patterns, benefit-risk assessments, humanistic, societal and economic burden of platelet transfusion (PT). Methods: Publications from 1998 to June 27, 2018 were identified, based on databases searches including MEDLINE®; Embase and Cochrane Database of Systematic Reviews. Data from studies meeting pre-specified criteria were extracted and validated by independent reviewers. Data were obtained for efficacy and safety from randomized controlled trials (RCTs); data for epidemiology, treatment patterns, effectiveness, safety, humanistic and societal burden from real-world evidence (RWE) studies; and economic data from both. Results: A total of 3425 abstracts, 194 publications (190 studies) were included. PT use varied widely, from 0%-100% of TCP patients; 1.7%-24.5% in large studies (>1000 patients). Most were used prophylactically rather than therapeutically. 5 of 43 RCTs compared prophylactic PT with no intervention, with mixed results. In RWE studies PT generally increased platelet count (PC). This increase varied by patient characteristics and hence did not always translate into a clinically significant reduction in bleeding risk. Safety concerns included infection risk, alloimmunization and refractoriness with associated cost burden. Discussion: In RCTs and RWE studies there was significant heterogeneity in study design and outcome measures. In RWE studies, patients receiving PT may have been at higher risk than those not receiving PT creating potential bias. There were limited data on humanistic and societal burden. Conclusion: Although PTs are used widely for increasing PC in TCP, it is important to understand the limitations of PTs, and to explore the use of alternative treatment options where available.

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.

Thrombocytopenia during intravenous valproic acid therapy in the neurological intensive care unit

WHAT IS KNOWN AND OBJECTIVE

Thrombocytopenia is a common laboratory abnormality among critically ill patients under neurological intensive care unit (NCU) care. Valproic acid (VPA), a widely used antiepileptic drug, is one of the common causes of drug-induced thrombocytopenia. The purpose of this study was to estimate the incidence and risk factors of thrombocytopenia after intravenous VPA therapy among the patients admitted to NCU.

METHODS

We retrospectively reviewed the medical records of patients who were treated with intravenous VPA during their NCU stay between January 2014 and December 2018. We studied the frequency of thrombocytopenia and further evaluated the risk of thrombocytopenia in these patients.

RESULTS

Among the 283 patients (181 male [64.0%], mean age: [61.0 ± 14.9] years) who were treated with intravenous VPA, thrombocytopenia was observed in 104 patients (36.7%). Thrombocytopenia was associated with several risk factors, including lower baseline platelet counts (<200 × 10⁹ /L); aetiologies other than intracranial or subarachnoid haemorrhage; longer use of VPA (more than 3 days); higher daily dose of VPA (more than 1000 mg/d); concurrent use of VPA with other antiepileptic drugs; infection; and the use of mechanical ventilation. Multivariate analysis found several independent risk factors of thrombocytopenia with intravenous VPA therapy, including lower baseline platelet counts, aetiologies other than intracranial or subarachnoid haemorrhage, use of VPA for more than 3 days and infection.

WHAT IS NEW AND CONCLUSION

Thrombocytopenia is common in NCU patients. Because several clinical and laboratory factors are associated with thrombocytopenia, careful use of VPA should be considered in patients with these risk factors.

Thrombotic Thrombocytopenic Purpura, Heparin-Induced Thrombocytopenia, and Disseminated Intravascular Coagulation

Hemostatic abnormalities are common among critically ill patients and are associated with a high risk of bleeding. The abnormalities range from isolated thrombocytopenia or prolongation of global coagulation assays to complex disease states, such as thrombotic microangiopathic syndromes, and can be associated with a wide range of conditions, including trauma, surgery, acute disease processes, cardiopulmonary bypass, and exposure to drugs and blood products. Prompt identification of underlying causes is important because treatment strategies vary. Moreover, prompt initiation of both supportive and specific treatments is vital to decrease the morbidity and mortality in the intensive care unit.

Effects of Baseline Thrombocytopenia and Platelet Decrease Following Renal Replacement Therapy Initiation in Patients With Severe Acute Kidney Injury

OBJECTIVES

Thrombocytopenia is common in critically ill patients with severe acute kidney injury and may be worsened by the use of renal replacement therapy. In this study, we evaluate the effects of renal replacement therapy on subsequent platelet values, the prognostic significance of a decrease in platelets, and potential risk factors for platelet decreases.

DESIGN

Post hoc analysis of the Acute Renal Failure Trial Network Study.

SETTING

The Acute Renal Failure Trial Network study was a multicenter, prospective, randomized, parallel-group trial of two strategies for renal replacement therapy in critically ill patients with acute kidney injury conducted between November 2003 and July 2007 at 27 Veterans Affairs and university-affiliated medical centers.

SUBJECTS

The Acute Renal Failure Trial Network study evaluated 1,124 patients with severe acute kidney injury requiring renal replacement therapy.

INTERVENTIONS

Predictor variables were thrombocytopenia at initiation of renal replacement therapy and platelet decrease following renal replacement therapy initiation.

MEASUREMENTS AND MAIN RESULTS

Outcomes were mortality at 28 days, 60 days, and 1 year, renal recovery, renal replacement therapy free days, ICU-free days, and hospital-free days. Baseline thrombocytopenia in patients requiring renal replacement therapy was associated with increased mortality and was also associated with lower rates of renal recovery. A decrease in platelet values following renal replacement therapy initiation was associated with increased mortality. Continuous renal replacement therapy was not an independent predictor of worsening thrombocytopenia compared with those treated with intermittent hemodialysis.

CONCLUSIONS

Baseline thrombocytopenia and platelet decrease following renal replacement therapy initiation were associated with increased mortality, and baseline thrombocytopenia was associated with decreased rates of renal recovery. Continuous renal replacement therapy did not decrease platelets compared with hemodialysis.

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.

Mechanisms of Thrombocytopenia During Septic Shock: A Multiplex Cluster Analysis of Endogenous Sepsis Mediators

BACKGROUND

Thrombocytopenia is a common feature of sepsis and may involve various mechanisms often related to the inflammatory response. This study aimed at evaluating factors associated with thrombocytopenia during human septic shock. In particular, we used a multiplex analysis to assess the role of endogenous sepsis mediators.

METHODS

Prospective, observational study. Thrombocytopenia was defined as an absolute platelet count <100 G/L or a 50% relative decrease in platelet count during the first week of septic shock. Plasma concentrations of 27 endogenous mediators involved in sepsis and platelet pathophysiology were assessed at day-1 using a multi-analyte Milliplex human cytokine kit. Patients with underlying diseases at risk of thrombocytopenia (hematological malignancies, chemotherapy, cirrhosis, and chronic heart failure) were excluded.

RESULTS

Thrombocytopenia occurred in 33 (55%) of 60 patients assessed. Patients with thrombocytopenia were more prone to present with extrapulmonary infections and bacteremia. Disseminated intravascular coagulation was frequent (81%) in these patients. Unbiased hierarchical clustering identified five different clusters of sepsis mediators, including one with markers of platelet activation (e.g., thrombospondin-1) positively associated with platelet count, one with markers of inflammation (e.g., tumor necrosis factor alpha and heat shock protein 70), and endothelial dysfunction (e.g., intercellular adhesion molecule-1 and vascular cell adhesion molecule-1) negatively associated with platelet count, and another involving growth factors of thrombopoiesis (e.g., thrombopoietin), also negatively associated with platelet count. Surrogates of hemodilution (e.g., hypoprotidemia and higher fluid balance) were also associated with thrombocytopenia.

CONCLUSION

Multiple mechanisms seemed involved in thrombocytopenia during septic shock, including endothelial dysfunction/coagulopathy, hemodilution, and altered thrombopoiesis.

Thrombocytopenia in Intensive Care Unit

How to cite this article: Aluru N, Samavedam S. Thrombocytopenia in Intensive Care Unit. Indian J Crit Care Med 2019;23(Suppl 3):S185–S188.

Genome-Wide Association Study Links Receptor Tyrosine Kinase Inhibitor Sprouty 2 to Thrombocytopenia after Coronary Artery Bypass Surgery

INTRODUCTION

 Thrombocytopenia after cardiac surgery independently predicts stroke, acute kidney injury and death. To understand the underlying risks and mechanisms, we analysed genetic variations associated with thrombocytopenia in patients undergoing coronary artery bypass grafting (CABG) surgery.

MATERIALS AND METHODS

 Study subjects underwent isolated on-pump CABG surgery at Duke University Medical Center. Post-operative thrombocytopenia was defined as platelet count < 100 × 10⁹/L. Using a logistic regression model adjusted for clinical risk factors, we performed a genome-wide association study in a discovery cohort (n = 860) and validated significant findings in a replication cohort (n = 296). Protein expression was assessed in isolated platelets by immunoblot.

RESULTS

 A total of 63 single-nucleotide polymorphisms met a priori discovery thresholds for replication, but only 1 (rs9574547) in the intergenic region upstream of sprouty 2 (SPRY2) met nominal significance in the replication cohort. The minor allele of rs9574547 was associated with a lower risk for thrombocytopenia (discovery cohort, odds ratio, 0.45, 95% confidence interval, 0.30-0.67, p = 9.76 × 10^-5) with the overall association confirmed by meta-analysis (meta-p = 7.88 × 10^-6). Immunoblotting demonstrated expression of SPRY2 and its dynamic regulation during platelet activation. Treatment with a functional SPRY2 peptide blunted platelet extracellular signal-regulated kinase (ERK) phosphorylation after agonist stimulation.

CONCLUSION

 We identified the association of a genetic polymorphism in the intergenic region of SPRY2 with a decreased incidence of thrombocytopenia after CABG surgery. Because SPRY2-an endogenous receptor tyrosine kinase inhibitor-is present in platelets and modulates essential signalling pathways, these findings support a role for SPRY2 as a novel modulator of platelet responses after cardiac surgery.

Risk factors for complications and mortality of percutaneous endoscopic gastrostomy insertion

BACKGROUND

Percutaneous endoscopic gastrostomy (PEG) is a relatively safe procedure; however, acute and chronic complications of PEG have been reported. We aimed to determine risk factors associated with complications and 30-day mortality after PEG, based on 11 years of experience at a single tertiary hospital.

METHODS

In total, 401 patients who underwent first PEG insertion at the Asan Medical Center, Seoul, Korea, between January 2005 and December 2015 were eligible. Medical records were retrospectively reviewed to determine clinical characteristics and outcomes of 139 and 262 patients who underwent pull-type and introducer-type PEG, respectively.

RESULTS

The median age of the overall population was 68 years, and the median body mass index was 19.5 kg/m2. Acute and chronic complications developed in 96 (23.9%) and 105 (26.2%) patients. Acute ileus and chronic tube obstruction were significantly more frequent in the introducer-type PEG group (p = 0.033 and 0.001, respectively). The 30-day mortality rate was 5.0% (median survival: 10.5 days). Multivariate analysis revealed that underlying malignancy was a predictor of acute complications; age ≥ 70 years and diabetes mellitus were predictors of chronic complications. The median follow-up was 354 days. Neurologic disease and malignancy were the most common indications for PEG. Neurologic diseases were classified into two groups: stroke and the other neurologic disease group (including dementia, Parkinson's disease, neuromuscular disease, and hypoxic brain damage). Multivariate analysis showed that 30-day mortality was significantly lower in the other neurologic disease group and higher in patients with platelet count < 100,000/μL, and C-reactive protein (CRP) ≥ 5 mg/dL.

CONCLUSIONS

PEG is a relatively safe and feasible procedure, but it was associated with significantly higher early mortality rate in patients with platelet count < 100,000/μL or CPR≥5mg/dL, and lower early mortality rate in neurologic disease group including dementia, Parkinson's disase, neuromuscular disease, and hypoxic brain damage. In addition, acute complications in patients with underlying malignancy, and chronic complications in patients aged ≥70 and those with diabetes mellitus should be considered during and after PEG.

Evaluation of Thrombocytopenia in Critically Ill Patients Receiving Continuous Renal Replacement Therapy

BACKGROUND

Continuous renal replacement therapy (CRRT) may be associated with thrombocytopenia in critically ill patients. A confounding factor is concomitant use of unfractionated heparin (UFH) and suspicion for heparin-induced thrombocytopenia (HIT).

OBJECTIVE

To determine the impact of CRRT on platelet count and development of thrombocytopenia.

METHODS

Retrospective analyses evaluated the intrapatient change in platelet count following CRRT initiation. Critically ill adult patients who received CRRT for at least 48 hours were included. The primary outcome was intrapatient change in platelet count from CRRT initiation through the first 5 days of therapy. Secondary outcomes included thrombocytopenia incidence, identification of concomitant factors associated with thrombocytopenia, and frequency of HIT.

RESULTS

80 patients were included. Median platelet count at CRRT initiation (D0) was 128000/µL (81500-212500/µL), which was higher than those on subsequent post-CRRT days (D1: 104500/µL [63000-166750/µL]; D2: 88500/µL [53500-136750/µL]; D3: 91000/µL [49000-138000/µL]; D4: 93000/µL [46000-134000/µL]; and D5: 76000/µL [45500-151000/µL]; P < 0.05 for all). Twenty-five (35%) patients had thrombocytopenia on CRRT D0 compared with D2 (56.3%), D3 (58.7%), and D5 (59.1%); P < 0.05 for all. Controlling for potential confounders, Sequential Organ Failure Assessment score at the time of CRRT initiation was the only independent factor associated with thrombocytopenia. One (1.3%) patient had confirmed HIT. Conclusion and Relevance: This study is the first to demonstrate serial decreases in platelet count across multiple days after CRRT initiation. These data may provide additional insight to thrombocytopenia development in critically ill patients receiving heparin while on CRRT that is not associated with HIT.

Assessing thrombocytopenia in the intensive care unit: the past, present, and future

Thrombocytopenia is common among patients admitted to the intensive care unit (ICU). Multiple pathophysiological mechanisms may contribute, including thrombin-mediated platelet activation, dilution, hemophagocytosis, extracellular histones, ADAMTS13 deficiency, and complement activation. From the clinical perspective, the development of thrombocytopenia in the ICU usually indicates serious organ system derangement and physiologic decompensation rather than a primary hematologic disorder. Thrombocytopenia is associated with bleeding, transfusion, and adverse clinical outcomes including death, though few deaths are directly attributable to bleeding. The assessment of thrombocytopenia begins by looking back to the patient's medical history and presenting illness. This past information, combined with careful observation of the platelet trajectory in the context of the patient's clinical course, offers clues to the diagnosis and prognosis. Management is primarily directed at the underlying disorder and transfusion of platelets to prevent or treat clinical bleeding. Optimal platelet transfusion strategies are not defined, and a conservative approach is recommended.

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.

Platelet Counts and Postoperative Stroke After Coronary Artery Bypass Grafting Surgery

BACKGROUND

Declining platelet counts may reveal platelet activation and aggregation in a postoperative prothrombotic state. Therefore, we hypothesized that nadir platelet counts after on-pump coronary artery bypass grafting (CABG) surgery are associated with stroke.

METHODS

We evaluated 6130 adult CABG surgery patients. Postoperative platelet counts were evaluated as continuous and categorical (mild versus moderate to severe) predictors of stroke. Extended Cox proportional hazard regression analysis with a time-varying covariate for daily minimum postoperative platelet count assessed the association of day-to-day variations in postoperative platelet count with time to stroke. Competing risks proportional hazard regression models examined associations between day-to-day variations in postoperative platelet counts with timing of stroke (early: 0-1 days; delayed: ≥2 days).

RESULTS

Median (interquartile range) postoperative nadir platelet counts were 123.0 (98.0-155.0) × 10/L. The incidences of postoperative stroke were 1.09%, 1.50%, and 3.02% for platelet counts >150 × 10/L, 100 to 150 × 10/L, and <100 × 10/L, respectively. The risk for stroke increased by 12% on a given postoperative day for every 30 × 10/L decrease in platelet counts (adjusted hazard ratio [HR], 1.12; 95% confidence interval [CI], 1.01-1.24; P= .0255). On a given day, patients with moderate to severe thrombocytopenia were almost twice as likely to develop stroke (adjusted HR, 1.89; 95% CI, 1.13-3.16; P= .0155) as patients with nadir platelet counts >150 × 10/L. Importantly, such thrombocytopenia, defined as a time-varying covariate, was significantly associated with delayed (≥2 days after surgery; adjusted HR, 2.83; 95% CI, 1.48-5.41; P= .0017) but not early postoperative stroke.

CONCLUSIONS

Our findings suggest an independent association between moderate to severe postoperative thrombocytopenia and postoperative stroke, and timing of stroke after CABG surgery.

The association between platelet transfusions and bleeding in critically ill patients with thrombocytopenia

BACKGROUND

Platelet transfusions are commonly used to treat critically ill patients with thrombocytopenia. Whether platelet transfusions are associated with a reduction in the risk of major bleeding is unknown.

PATIENTS/METHODS

Observational cohort study nested in a previous multicenter, randomized thromboprophylaxis trial in the intensive care unit (ICU). The objective was to evaluate the association between platelet transfusions and adjudicated major bleeding events. Platelet transfusion episodes were reviewed for timing of administration, product type, and dose. Major bleeding with and without platelet transfusions was adjusted for severity of thrombocytopenia, use of anti-platelet agents, surgery and other covariates. Secondary outcomes were thrombosis, death in ICU and platelet count increment.

RESULTS

Among 2,256 patients, 71 (3.1%) received 190 platelet transfusions. Of those, 121 (63.7%) were administered to 54 non-bleeding, thrombocytopenic patients. Adjusted rates of major bleeding were not statistically different with or without the administration of platelet transfusions (hazard ratio for transfused patients 0.85; 95% confidence interval, 0.42-1.72). We did not find a significant association between platelet transfusion use and thrombosis or death in ICU in adjusted analyses. Thrombocytopenia, anemia, major or minor bleeding and use of anticoagulants were associated with platelet transfusion administration. The median post-transfusion platelet count increment was 20×109/L at 3.5 hours post-transfusion.

CONCLUSIONS

Rates of major bleeding were not different for patients who did and did not receive platelet transfusions. Inferences were limited by the small number of transfused patients. Clinical trials are needed to better investigate the potential hemostatic benefit and potential harms of platelet transfusions for this high-risk population.

Thrombocytopenia on the first day of emergency department visit predicts higher risk of acute kidney injury among elderly patients

Background

Few studies have addressed risk factors for acute kidney injury (AKI) in geriatric patients. We investigated whether thrombocytopenia was a risk factor for AKI in geriatric patients with medical illnesses.

Methods

A prospective cohort study was conducted, by recruiting elderly (≥65 years) patients who visited the emergency department (ED) for medical illnesses during 2014. They all received hemogram for platelet count determination, and were stratified according to the presence of thrombocytopenia (platelets, <150 K/μL) during their initial ED evaluation. They were prospectively followed up during their ED stay. We analyzed the relationship between the diagnosis of thrombocytopenia and subsequent AKI after ED stay, using Cox proportional hazard modeling, with platelet count as a continuous variable or thrombocytopenia as a categorical variable.

Results

Of 136 elderly patients (mean age of 80.7 ± 8.2 years, 40% with chronic kidney disease, and 39% with diabetes) enrolled, 22.8% presented with thrombocytopenia, without differences in baseline renal function. After a mean ED stay of 4.4 ± 2.1 days, 41.9% developed AKI (52.6% Kidney Disease Improving Global Outcomes [KDIGO] grade 1, 24.6% grade 2, and 22.8% grade 3). Patients with higher AKI severity had stepwise lower platelet counts compared to those without AKI. The Cox proportional hazard model revealed that lower platelet count as a continuous variable (hazard ratio [HR] 0.984, 95% confidence interval [CI] 0.975–0.994) and as a categorical variable (presence of thrombocytopenia) (HR 1.86, 95% CI 1.06–3.27) increased the risk of AKI. The sensitivity analyses accounting for nephrotoxic medications use, including non-steroidal anti-inflammatory drugs, vancomycin, and contrast, yielded similar results.

Discussion

Thrombocytopenia is common among ED-visiting elderly, and the potential relationship between platelet counts and the risk of AKI suggests the utility of checking hemogram for those at-risk ofdeveloping adverse renal events.

Conclusion

Thrombocytopenia on initial presentation might indicate an increased risk of AKI among elderly patients with medical illnesses.

Effect of Persistent Thrombocytopenia on Mortality in Surgical Critical Care Patients

Thrombocytopenia is common among surgical critically ill patients. The relationship between the duration of thrombocytopenia and mortality is not well studied. This retrospective 12-month cohort study was designed to evaluate the association between persistent thrombocytopenia and mortality among surgical critically ill patients to determine the risk factors for persistent thrombocytopenia. The study included adult patients consecutively admitted to the surgical intensive care unit (SICU) at our institution. Patients with a diagnosis of thrombocytopenia were identified from a prospective critical care database. We defined patients with persistent thrombocytopenia as those with thrombocytopenia lasting more than 7 consecutive days. The primary outcome of this study was 28-day mortality and the secondary outcomes were lengths of SICU stay and hospital stay. Fifty-one patients experienced persistent thrombocytopenia and 71 experienced nonpersistent thrombocytopenia. Among patients with persistent thrombocytopenia, mortality was significantly higher, and SICU and hospital stays were longer than those with nonpersistent thrombocytopenia. Risk factor analysis failed to predict which patients with thrombocytopenia would develop into persistent thrombocytopenia. Persistent thrombocytopenia is a clinically significant disorder and is associated with poorer outcomes. Future studies are needed to further define this process.

The Incidence, Clinical Outcomes, and Risk Factors of Thrombocytopenia in Intra-Abdominal Infection Patients: A Retrospective Cohort Study

Background

Studies on the incidence and risk factors of thrombocytopenia among intra-abdominal infection patients remain absent, hindering efficacy assessments regarding thrombocytopenia prevention strategies.

Methods

We retrospectively studied 267 consecutively enrolled patients with intra-abdominal infections. Occurrence of thrombocytopenia was scanned for all patients. All-cause 28-day mortality was recorded. Variables from univariate analyses that were associated with occurrence of hospital-acquired thrombocytopenia were included in a multivariable logistic regression analysis to determine thrombocytopenia predictors.

Results

Median APACHE II score and SOFA score of the whole cohort was 12 and 3 respectively. The overall ICU mortality was 7.87% and the 28-day mortality was 8.98%. The incidence of thrombocytopenia among intra-abdominal infection patients was 21.73%. Regardless of preexisting or hospital-acquired one, thrombocytopenia is associated with an increased ICU mortality and 28-day mortality as well as length of ICU or hospital stay. A higher SOFA and ISTH score at admission were significant hospital-acquired thrombocytopenia risk factors.

Conclusions

This is the first study to identify a high incidence of thrombocytopenia in patients with intra-abdominal infections. Our findings suggest that the inflammatory milieu of intra-abdominal infections may uniquely predispose those patients to thrombocytopenia. More effective thrombocytopenia prevention strategies are necessary in intra-abdominal infection patients.

Interrater agreement for two systems used to determine the probability of heparin-induced thrombocytopenia

PURPOSE

The interrater reliability of the 4T's method and the HIT expert probability (HEP) score for clinical evaluation of suspected heparin-induced thrombocytopenia (HIT) was investigated.

METHODS

Patients hospitalized over a three-year period who were tested for HIT via anti-platelet factor 4 (anti-PF4) antigen assay were identified using laboratory data; 127 patient cases met the study inclusion criteria. Nine clinical pharmacists with expertise in HIT management evaluated the 127 cases using two pretest scoring systems: the 4T's score and the HEP score. Each case was independently evaluated using both 4T's and HEP scores. The primary endpoint was interrater agreement of overall 4T's and HEP scores and individual item scores.

RESULTS

Raw agreement of values assigned by the two raters for each of the four items comprising the 4T's score ranged from 0.54 to 0.86, with agreement of 0.63 for final patient categorizations. Raw agreement of rater weightings of the eight HEP scoring items ranged from 0.34 to 1.0; for dichotomization of patients at the suggested screening cutoff value (>2.0), agreement was 0.65. Kappa coefficients were 0.15-0.45 for 4T's item scores and 0.17-0.70 for HEP score item scores. With both scoring systems, low rater agreement mainly related to determination of the timing of thrombocytopenia and possible other causes of the disorder.

CONCLUSION

In a retrospective study, inter-rater agreement in scoring of HIT probability via the 4T's and HEP scoring systems was relatively low. The HEP score did not increase interrater reliability or correlation with anti-PF4 antibodies compared with the 4T's score.