Effect of severe thrombocytopenia on patient outcome after liver transplantation

Relationship between thrombocytopenia and prognosis in children with septic shock: a retrospective cohort study

Septic shock is a life-threatening disease worldwide often associated with thrombocytopenia. Platelets play a crucial role in bridging the gap between immunity, coagulation, and endothelial cell activation, potentially influencing the course of the disease. However, there are few studies specifically evaluating the impact of thrombocytopenia on the prognosis of pediatric patients. Therefore, the study investigates effects of early thrombocytopenia in the prognosis of children with septic shock. Pediatric patients with septic shock from 2015 to 2022 were included monocentrically. Thrombocytopenia was defined as a platelet count of <100 × 109/L during the first 24 hours of septic shock onset. The primary outcome was the 28-day mortality. Propensity score matching was used to pair patients with different platelet counts on admission but comparable disease severity. A total of 419 pediatric patients were included in the analysis. Patients with thrombocytopenia had higher 28-day mortality (55.5% vs. 38.7%, p = .005) compared to patients with no thrombocytopenia. Thrombocytopenia was associated with reduced 28-PICU free days (median value, 0 vs. 13 days, p = .003) and 28-ventilator-free (median value, 0 vs. 19 days, p = .001) days. Among thrombocytopenia patients, those with platelet count ≤50 × 109/L had a higher 28-day mortality rate (63.6% vs. 45%, p = .02). Multiple logistic regression showed that elevated lactate (adjusted odds ratio (OR) = 1.11; 95% confidence interval (CI): 1.04-1.17; P <0.001) and white blood cell (WBC) count (OR = 0.97; 95% CI: 0.95-0.99; p = .003) were independent risk factors for the development of thrombocytopenia. Thrombocytopenia group had increased bleeding events, blood product transfusions, and development of organ failure. In Kaplan-Meier survival estimates, survival probabilities at 28 days were greater in patients without thrombocytopenia (p value from the log-rank test, p = .004). There were no significant differences in the type of pathogenic microorganisms and the site of infection between patients with and without thrombocytopenia. In conclusion, thrombocytopenia within 24 hours of shock onset is associated with an increased risk of 28-day mortality in pediatric patients with septic shock.

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.

Partial splenectomy in children undergoing liver transplantation or venous shunt for severe hypersplenism: A case control comparative study

BACKGROUND AND AIM

Hypersplenism is a consequence of portal hypertension and splenomegaly secondary to cirrhosis or portal cavernoma in children. In order to avoid persistent hypersplenism and splenomegaly after liver transplantation (LT) or venous shunt (VS), partial splenectomy (PS) may represent a relevant therapeutic option. The aim of this retrospective study was to evaluate the results of PS performed in children presenting hypersplenism.

METHODS

The following end-points were evaluated: (1) reversion of hypersplenism and its durability over time, (2) postoperative outcome, (3) courses of spleen size and volume and (4) comparison to a control group in which PS was not performed.

RESULTS

Between 1996 and 2020, 16 children underwent PS associated with LT (8 cases) for cirrhosis or VS (8 cases) for portal cavernoma. From Day 0 to 1 month, mean platelet and white blood cell counts (WBC) dramatically improved from 48 ± 19 at day 0 to 176 ± 70 × 10⁹/L (P < 0.0001) and from 2469 ± 853 to 7198 ± 3982/L (P = 0.001) respectively. PS allowed significant reduction of splenic length and volume from 176 ± 33 to 112 ± 24 cm (P < 0.0001) and from 1228 ± 464 to 450 ± 297 cm³ (P = 0.0003) respectively. After a mean follow-up of 92.6 ± 84.7 months (range: 4.1-210.7), 14 patients are alive with normal platelet and WBC counts and persistent spleen size reduction. Compared to control group, PS was associated with a significant platelet count rise from baseline to one year.

CONCLUSIONS

PS appears to be effective for treatment of hypersplenism and splenomegaly in combination with LT or VS without compromising outcome.

Dualistic role of platelets in living donor liver transplantation: Are they harmful?

Platelets are anucleate fragments mainly involved in hemostasis and thrombosis, and there is emerging evidence that platelets have other nonhemostatic potentials in inflammation, angiogenesis, regeneration and ischemia/reperfusion injury (I/R injury), which are involved in the physiological and pathological processes during living donor liver transplantation (LDLT). LDLT is sometimes associated with impaired regeneration and severe I/R injury, leading to postoperative complications and decreased patient survival. Recent studies have suggested that perioperative thrombocytopenia is associated with poor graft regeneration and postoperative morbidity in the short and long term after LDLT. Although it is not fully understood whether thrombocytopenia is the cause or result, increasing platelet counts are frequently suggested to improve posttransplant outcomes in clinical studies. Based on rodent experiments, previous studies have identified that platelets stimulate liver regeneration after partial hepatectomy. However, the role of platelets in LDLT is controversial, as platelets are supposed to aggravate I/R injury in the liver. Recently, a rat model of partial liver transplantation (LT) was used to demonstrate that thrombopoietin-induced thrombocytosis prior to surgery accelerated graft regeneration and improved the survival rate after transplantation. It was clarified that platelet-derived liver regeneration outweighed the associated risk of I/R injury after partial LT. Clinical strategies to increase perioperative platelet counts, such as thrombopoietin, thrombopoietin receptor agonist and platelet transfusion, may improve graft regeneration and survival after LDLT.

Prediction Models for Sepsis-Associated Thrombocytopenia Risk in Intensive Care Units Based on a Machine Learning Algorithm

Sepsis-associated thrombocytopenia (SAT) is a common complication in the intensive care unit (ICU), which significantly increases the mortality rate and leads to poor prognosis of diseases. Machine learning (ML) is widely used in disease prediction in critically ill patients. Here, we aimed to establish prediction models for platelet decrease and severe platelet decrease in ICU patients with sepsis based on four common ML algorithms and identify the best prediction model. The research subjects were 1,455 ICU sepsis patients admitted to Dongyang People's Hospital affiliated with Wenzhou Medical University from January 1, 2015, to October 31, 2019. Basic clinical demographic information, biochemical indicators, and clinical outcomes were recorded. The prediction models were based on four ML algorithms: random forest, neural network, gradient boosting machine, and Bayesian algorithms. Thrombocytopenia was found to occur in 732 patients (49.7%). The mechanical ventilation time and length of ICU stay were longer, and the mortality rate was higher for the thrombocytopenia group than for the non-thrombocytopenia group. The models were validated on an online international database (Medical Information Mart for Intensive Care III). The areas under the receiver operating characteristic curves (AUCs) of the four models for the prediction of thrombocytopenia were between 0.54 and 0.72. The AUCs of the models for the prediction of severe thrombocytopenia were between 0.70 and 0.77. The neural network and gradient boosting machine models effectively predicted the occurrence of SAT, and the Bayesian models had the best performance in predicting severe thrombocytopenia. Therefore, these models can be used to identify such high-risk patients at an early stage and guide individualized clinical treatment, to improve the prognosis of diseases.

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.

Incidence, predictors, and prognosis of thrombocytopenia among patients undergoing intra-aortic balloon pumping in the intensive care unit: a propensity score analysis

OBJECTIVE

To explore the incidence, predictors, and prognosis of intra-aortic balloon pumping (IABP)-related thrombocytopenia in critically ill patients.

METHODS

This multi-center study used the eICU Collaborative Research Database V1.2, comprising data on > 130,000 patients from multiple intensive care units (ICUs) in America between 2014 and 2015. A total of 710 patients undergoing IABP were included. Thrombocytopenia was defined as a drop in platelet count > 50% from baseline. From the cohort, 167 patients who developed thrombocytopenia were matched 1:1 with 167 patients who did not, after propensity score (PS) matching. The associations between IABP-related thrombocytopenia and clinical outcomes were examined by multivariable logistic regression.

RESULTS

Among 710 patients undergoing IABP, 249 patients (35.07%) developed thrombocytopenia. The APACHE IVa score was a predictor of thrombocytopenia [adjusted odds ratio (OR) = 1.09, 95% confidence interval (CI): 1.02-1.15]. After 1:1 PS matching, in-hospital mortality (adjusted OR = 0.76, 95% CI: 0.37-1.56) and in-ICU mortality (adjusted OR = 0.74, 95% CI: 0.34-1.63) were similar between the thrombocytopenia and non-thrombocytopenia groups. However, major bleeding occurred more frequently in the thrombocytopenia group (adjusted OR = 2.54, 95% CI: 1.54-4.17). In-hospital length of stay (LOS) and in-ICU LOS were significantly longer in patients who developed thrombocytopenia than in those who did not (9.71vs. 7.36, P < 0.001; 5.13 vs. 2.83, P < 0.001).

CONCLUSIONS

Among patients undergoing IABP in the ICUs, thrombocytopenia was not associated with a difference in in-hospital mortality or in-ICU mortality; however, thrombocytopenia was significantly associated with a greater risk of major bleeding and increased in-ICU and in-hospital LOS.

Preoperative platelet count predicts posttransplant portal vein complications in orthotopic liver transplantation: a propensity score analysis

Background

The role of platelets on the prognosis of patients with liver transplantation remains unclear. Thus, we aimed to evaluate the influence of preoperative platelet count on postoperative morbidity after liver transplantation.

Methods

Clinical data of the patients who received liver transplantation from January 2015 to September 2018 were evaluated.

Results

Of the 329 patients included, the average age was 46.71 ± 0.55 years, and 243 were men (75.2%). The incidence of posttransplant portal vein complication was significantly higher in the high platelet count group (> 49.5 × 10⁹/L; n = 167) than in the low platelet count group (≤ 49.5 × 10⁹/L, n = 162, 12.6% vs. 1.9%). After multivariable regression analysis, high platelet count was independently associated with postoperative portal vein complication (odds ratio [OR]: 8.821, 95% confidence interval [CI]: 2.260 to 34.437). After the inverse probability of treatment weighting analysis, patients in the high platelet count group had significantly higher risk of portal vein complication (OR: 9.210, 95%CI: 1.907 to 44.498, p = 0.006) and early allograft dysfunction (OR: 2.087, 95%CI: 1.131 to 3.853, p = 0.019).

Conclusions

Preoperative platelet count > 49.5 × 10⁹/L was an independent risk factor for posttransplant portal vein complication and early allograft dysfunction. High preoperative platelet count could be an adverse prognostic predictor for liver transplantation recipients.

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.

Clinical Implications of Thrombocytopenia at Cardiogenic Shock Presentation: Data from a Multicenter Registry

PURPOSE

Thrombocytopenia (platelet count <150×10³/μL) is associated with poor outcomes in various critical illness settings. However, the prognostic value of platelet count in patients with cardiogenic shock (CS) remains unclear.

MATERIALS AND METHODS

We enrolled 1202 patients between January 2014 and December 2018 from a multicenter retrospective-prospective cohort registry of CS. Clinical characteristics and treatment outcomes were compared between the patients with and without thrombocytopenia.

RESULTS

At presentation with CS, 244 (20.3%) patients had thrombocytopenia. The patients with thrombocytopenia had lower blood pressure, hemoglobin level, and worse liver and renal functions compared to the patients without. During hospitalization, the patients with thrombocytopenia had more frequent gastrointestinal bleeding (10.5% vs. 3.8%, p=0.009), sepsis (8.3% vs. 2.6%, p=0.013), requirement of renal replacement therapy (36.5% vs. 18.9%, p<0.001), requirement of mechanical ventilation (65.2% vs. 54.4%, p=0.003), longer intensive care unit stay (8 days vs. 4 days, p<0.001), and thirty-day mortality (40.2% vs. 28.5%, p<0.001) compared to those without. In addition, the platelet count was an independent predictor of 30-day mortality (per 10³/μL decrease; adjusted hazard ratio: 1.002, 95% confidence interval: 1.000-1.003, p=0.021).

CONCLUSION

Thrombocytopenia at CS presentation was associated with worse clinical findings, higher frequencies of complications, and longer stay at the intensive care unit. Also, thrombocytopenia was independently associated with increased 30-day mortality. (Clinical trial registration No. NCT02985008).

Platelet and liver regeneration after liver surgery

The success of liver surgery, including resection and transplantation, is largely dependent on the ability of the liver to regenerate. Despite substantial improvement in surgical techniques and perioperative care, one of the main concerns is post-hepatectomy liver failure and early allograft dysfunction, both of which are associated with impaired liver regeneration. Recent studies have demonstrated the positive role of platelets in promoting liver regeneration and protecting hepatocytes; however, the underlying mechanisms responsible for these effects are not fully understood. In this review, we updated the accumulated evidence of the role of platelets in promoting liver regeneration, with a focus on liver resection and liver transplantation. The goal of these studies was to support the clinical implementation of platelet agents, such as thrombopoietin receptor agonists, to augment liver regeneration after liver surgery. This "platelet therapy" may become a treatment choice for post-hepatectomy liver failure and early allograft dysfunction.

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.

Thrombocytopenia after liver transplantation: Should we care?

Transient thrombocytopenia is a common phenomenon after liver transplantation. After liver transplantation (LT), platelet count decreases and reaches a nadir on postoperative days 3-5, with an average reduction in platelet counts of 60%; platelet count recovers to preoperative levels approximately two weeks after LT. The putative mechanisms include haemodilution, decreased platelet production, increased sequestration, medications, infections, thrombosis, or combination of these processes. However, the precise mechanisms remain unclear. The role of platelets in liver transplantation has been highlighted in recent years, and particular attention has been given to their effects beyond hemostasis and thrombosis. Previous studies have demonstrated that perioperative thrombocytopenia causes poor graft regeneration, increases the incidence of postoperative morbidity, and deteriorates the graft and decreases patient survival in both the short and long term after liver transplantation. Platelet therapies to increase perioperative platelet counts, such as thrombopoietin, thrombopoietin receptor agonist, platelet transfusion, splenectomy, and intravenous immunoglobulin treatment might have a potential for improving graft survival, however clinical trials are lacking. Further studies are warranted to detect direct evidence on whether thrombocytopenia is the cause or result of poor-graft function and postoperative complications, and to determine who needs platelet therapies in order to prevent postoperative complications and thus improve post-transplant outcomes.

Relation between dynamic changes of platelet counts and 30-day mortality in severely burned patients

Thrombocytopenia is a common event in severely burned patients and associated with adverse outcome. The underlying relationship between the dynamic changes of platelet counts and mortality has not been well defined. We performed a 6-year retrospective chart of adult patients with a burn index of 50 or greater admitted to two burn centers and collected data on patient demographics, laboratory results, and patient outcomes. The mean daily increase in the platelet count (∆PC/∆t) from day 3 to day 10 was calculated, and 30-day mortality was determined. For the study, 141 survivors and 65 nonsurvivors were enrolled. The sequential changes in PCs presented a biphasic pattern after admission, with a slump to the nadir during the first 3 days and a subsequent recovery. With respect to 30-day mortality, compared with the AUC of APACHE-Ⅱ score (0.841), no significant difference was noted between ΔPC/ΔT and APACHE-Ⅱ score (p = 0.0648). The ΔPC/ΔT associated with the best discrimination between survivors and nonsurvivors was 20.57 × 10⁹/L due to the cutoff with optimal Youden index (0.453). By multiple logistic regression, ΔPC/ΔT ＜ 20.57 × 10⁹/L was one of the prognostic predictors of 30-day mortality. Furthermore, Kaplan-Meier estimates of hospital survival according to the size of ΔPC/ΔT revealed that a blunted increase with ΔPC/ΔT ＜ 20.57 × 10⁹/L was associated with increased 30-day mortality. A blunted daily increase in PCs, especially ΔPC/ΔT < 20.57 × 10⁹/L, is associated with increased 30-day mortality, which provides prognostic information for mortality risk assessment in severely burned patients.

Risks of bleeding and thrombosis in intensive care unit patients with haematological malignancies

Background

Patients with malignant haematological disease and especially those who require intensive care have an increased risk of bleeding and thrombosis, but none of these data were obtained in ICU patients only. We assessed the incidence of bleeding and thrombotic complications, use of blood products and risk factors for bleeding in an adult population of ICU patients with haematological malignancies.

Methods

We screened all patients with acute leukaemia and myelodysplastic syndrome admitted to a university hospital ICU during 2008–2012. Bleeding in ICU was scored according to the WHO grading system, and risk factors were evaluated using unadjusted and adjusted analyses.

Results

In total, 116 of 129 ICU patients were included; their median length of stay was 7 (IQR 2–16) days. Of these, 66 patients (57%) had at least one bleeding episode in ICU; they bled for 3 (2–6) days and most often from lower and upper airways and upper GI tract. Thirty-nine (59%) of the 66 patients had severe or debilitating (WHO grade 3 or 4) bleeding. The median platelet count on the day of grade 3 or 4 bleeding was 23 × 10⁹ per litre (IQR 13–39). Nine patients (8%) died in ICU following a bleeding episode; five of these had intra-cerebral haemorrhage. Platelet count on admission was associated with subsequent bleeding (adjusted odds ratio 1.18 (95% CI 1.03–1.35) for every 10 × 10⁹ per litre drop in platelet count, p = 0.016). Eleven of the 116 patients (9%) developed a clinically significant thrombosis in ICU, which was the cause of death in four patients. The median platelet count was 20 × 10⁹ per litre (15–48) at the time of thrombosis. The patients received a median of 6 units of red blood cells, 1 unit of fresh frozen plasma and 8 units of platelet concentrates in ICU.

Conclusions

Severe and debilitating bleeding complications were frequent in our ICU patients with haematological malignancies, but thrombosis also occurred in spite of low platelet counts. Platelet count on ICU admission was associated with subsequent bleeding.

Electronic supplementary material

The online version of this article (10.1186/s13613-017-0341-y) contains supplementary material, which is available to authorized users.

Intra-aortic balloon pumping and thrombocytopenia in patients with acute coronary syndrome : Incidence, risk factors, and prognosis

BACKGROUND

Thrombocytopenia is a frequently encountered phenomenon during intra-aortic balloon pumping (IABP), which may limit its prolonged utilization. The aim of the study was to explore the risk factors and clinical implications of IABP-associated thrombocytopenia in patients with acute coronary syndrome (ACS).

METHODS

We retrospectively analyzed the data of 222 patients with ACS undergoing invasive treatment strategy supported by IABP. The incidence and risk factors of IABP-associated thrombocytopenia, and the association between thrombocytopenia and relevant clinical endpoints (in-hospital death, bleeding according to the TIMI scale, and thromboembolic events), were analyzed.

RESULTS

IABP-associated thrombocytopenia was observed in 54.5% (121/222) of the patients. The incidence of thrombocytopenia was higher and the magnitude of reduction in platelet count was greater in the Arrow balloon group (n = 89) compared with the Datascope balloon group (n = 133; 68.5% vs. 45.1%, p = 0.001; 48.7% vs. 33.2%, p < 0.001; respectively). Independent predictors of thrombocytopenia included older age and Arrow balloon utilization (odds ratio [OR]: 1.054; 95% confidence interval [CI]: 1.028-1.080; p<0.001; OR: 2.468; 95%CI: 1.375-4.431; p = 0.002; respectively). The incidence of in-hospital death was higher in patients who developed thrombocytopenia than those who did not (9.1% vs. 2.0%, p = 0.041), and thrombocytopenia was correlated with in-hospital death (OR: 5.932; 95%CI: 1.221-28.822; p = 0.027). However, the rates of TIMI bleeding and thromboembolic events were similar between the two groups (5.8% vs. 5.0%, p = 1.000; 3.2% vs. 6.0%, p = 0.518; respectively), and thrombocytopenia was not associated with TIMI bleeding or thromboembolic events (OR: 0.940; 95%CI: 0.267-3.307; p = 0.923; OR: 0.541, 95%CI: 0.148-1.974, p = 0.352; respectively).

CONCLUSION

IABP-associated thrombocytopenia occurred in 54.5% of patients with ACS undergoing an invasive strategy and it was correlated with increased in-hospital mortality. Older age and use of the Arrow balloon may predict IABP-associated thrombocytopenia.

Dysfunction in Patients With Small-for-Size Grafts After Living Donor Liver Transplantation

The relationship between postoperative percentage fall of platelet (PLT) counts and graft dysfunction after living donor liver transplantation (LDLT) in recipients with small-for-size (SFS) graft has not been fully evaluated. We retrospectively studied 50 adult-to-adult LDLT recipients with a graft-to-recipient weight ratio of <0.8% between 1999 and 2011. Graft dysfunction was defined as the presence of hyperbilirubinemia, coagulopathy, or ascites on 3 consecutive days during the first postoperative week. Each clinical sign of dysfunction was assigned 1 point. Postoperative percentage fall in PLT counts, graft dysfunction score, and postoperative complications according to the Clavien-Dindo classification were investigated. Overall, 31 patients (62%) exhibited a PLT count fall of more than 50%, and 19 (38%) patients exhibited a PLT count fall of less than 50% at postoperative day (POD) 3. Receiver operating characteristic curve analysis indicated that at POD 3, the cutoff value of PLT count fall was 56% for a graft dysfunction score of 2 or 3 (sensitivity, 70%; specificity, 63.3%). Fourteen of 20 patients (70%) with a dysfunction score of 2 or 3 and 11 of 30 patients (37%) with a dysfunction score of 0 or 1 showed a fall in PLT count >56% at POD 3 (P = 0.021). Grade 2 to 5 complications were more observed in patients with a dysfunction score of 2 or 3 than in patients with a dysfunction score of 0 or 1 (P < 0.001). The fall of PLT count at POD 3 >56% is an ominous sign that can predict the graft dysfunction after LDLT in recipients with SFS graft.

Elevated Soluble Platelet Glycoprotein VI Levels in Patients After Living Donor Liver Transplantation

Plasma-soluble platelet glycoprotein VI (sGPVI) levels were examined in patients undergoing living donor liver transplantation (LDLT), and the relationship between platelet activation and thrombocytopenia was evaluated to understand the mechanism of thrombocytopenia in LDLT. Platelet counts were significantly higher in the donors compared to the recipient, and the plasma sGPVI levels increased in both groups after the operation. Regarding the relationship between the platelet counts and the sGPVI levels, the slope varied on different days, and it became negative on day 3, suggesting that the plasma sGPVI levels are related to platelet activation in LDLT. The frequency of complications was high in the nonsurvivors. The platelet counts were higher in the survivors than in the nonsurvivors on days 14 and 28. Although the plasma levels of sGPVI in the survivors increased after the operation, those in the nonsurvivors were high only on day 3. Although the ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 domain, member 13) levels were markedly reduced, von Willebrand factor (VWF) and VWF propeptide (VWFpp) were markedly elevated during LDLT. The antithrombin activity was significantly lower (day 14) and VWFpp (day 28) was significantly higher in the nonsurvivors than in the survivors. These findings suggest that platelet activation first occurs after LDLT, and it is high in the nonsurvivors on day 3. Thereafter, the hemostatic abnormality and vascular endothelial cell injuries may appear on days 14 and 28.

Decreased platelet count in patients receiving continuous veno-venous hemofiltration: a single-center retrospective study

BACKGROUND

A decreased platelet count may occur and portend a worse outcome in patients receiving continuous renal replacement therapy (CRRT). We aim to investigate the incidence of decreased platelet count and related risk factors in patients receiving CRRT.

METHODS

In this retrospective study, we screened all patients receiving continuous veno-venous hemofiltration (CVVH) at Jinling Hospital between November 2008 and October 2012. The patients were included who received uninterrupted CVVH for more than 72 h and had records of blood test for 4 consecutive days after ruling out pre-existing conditions that may affect the platelet count. Platelet counts before and during CVVH, illness severity, CVVH settings, and outcomes were analyzed.

RESULTS

The study included 125 patients. During the 3-day CVVH, 44.8% and 16% patients had a mild decline (20-49.9%) and severe decline (≥ 50%) in the platelet count,respectively; 37.6% and 16.0% patients had mild thrombocytopenia (platelet count 50.1-100 × 109/L) and severe thrombocytopenia (platelet count ≤ 50 × 10(9)/L), respectively. Patients with a severe decline in the platelet count had a significantly lower survival rate than patients without a severe decline in the platelet count (35.0% versus 59.0%, P=0.012), while patients with severe thrombocytopenia had a survival rate similar to those without severe thrombocytopenia (45.0% versus 57.1%, P=0.308). Female gender, older age, and longer course of the disease were independent risk factors for a severe decline in the platelet count.

CONCLUSIONS

A decline in the platelet count and thrombocytopenia are quite common in patients receiving CVVH. The severity of the decline in the platelet count rather than the absolute count during CVVH may be associated with hospital mortality. Knowing the risk factors for a severe decline in the platelet count may allow physicians to prevent such an outcome.

Drug-Induced Thrombocytopenia in the Critically Ill

Background:Drugs are suspected when obvious causes of intensive care unit (ICU)-acquired thrombocytopenia have been excluded. It has been estimated that 10% to 25% of cases may be drug induced. Objectives: The objectives of this study were to evaluate the risk of thrombocytopenia associated with drug classes commonly used in the ICU. Methods: Data concerning patients admitted for more than 48 hours between 1997 and 2011 were extracted from a research-purpose database. Patients with thrombocytopenia within the first 72 hours of admission and with diagnoses or interventions considered strongly associated with thrombocytopenia were excluded. Drug exposures were compared and adjusted for confounders using conditional logistic regression. Results: A total of 238 cases were identified after exclusions. Each case was matched according to sex, age, admission year, and admission unit with 1 control. In univariate analysis, quinolones (odds ratio [OR] = 1.56; 95% CI = 1.01-2.40) and extended spectrum β-lactams (OR = 1.71; 95% CI = 1.00-2.93) were significantly associated with an increased risk of thrombocytopenia. After adjusting for confounders, exposure to quinolones was the only drug class with a statistically significant increase in risk of thrombocytopenia (OR = 1.697; 95% CI = 1.002-2.873; P = 0.049). Conclusion: In this study of ICU-acquired thrombocytopenia, we found no association between the exposures to several antibiotic classes, anticonvulsants, antiplatelet agents, nonsteroidal anti-inflammatory agents, and heparins and thrombocytopenia. As linezolid was not studied, no conclusions can be drawn concerning this agent. The statistically significant association between quinolones and thrombocytopenia warrants further investigation.

Prolonged thrombocytopenia after living donor liver transplantation is a strong prognostic predictor irrespective of splenectomy: the significance of ADAMTS13 and graft function [corrected]

The precise mechanism of prolonged thrombocytopenia following living donor liver transplantation (LDLT) remains unclear. To determine risk factors associated with prolonged thrombocytopenia following LDLT, with a focus on the activity of ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type-1 motifs member 13) and the influence of splenectomy. Adult LDLT patients were divided into two groups on the basis of platelet counts (100 × 10(3)/μL) on POD 14: high and low platelet (HP and LP) groups. Survival analysis was performed in the 100 patients, and ADAMTS13 activity and von Willebrand factor (VWF) levels in the plasma were measured in 65 adult recipients. The 6-month survival rate was significantly lower in the LP group (n = 36) than in the HP group (n = 62) (61.1 vs. 93.5 %). ADAMTS13 activity had been significantly lower in the LP group (n = 23) than in the HP group (n = 42). The VWF/ADAMTS13 ratio was significantly higher in the LP group than in the HP group. The independent risk factors for thrombocytopenia on POD14 were preoperative AT levels and ADAMTS13 activity on POD14. TPO levels on POD14 were significantly higher in the LP group than in the HP group, while those on POD28 in the LP group were significantly decreased, despite the low platelet levels. Irrespective of splenectomy, platelet counts and ADAMTS13 activity in the LP group remained low until POD28, while VWF/ADAMTS13 ratio significantly increased until POD28. These results suggest that prolonged thrombocytopenia after LDLT was associated with not only a decrease in ADAMTS13 due to sinusoidal endothelial cell injury, but also low TPO production due to hepatocyte dysfunction, irrespective of splenectomy [corrected].

Thrombocytopenia in critically ill patients receiving thromboprophylaxis: frequency, risk factors, and outcomes

BACKGROUND

Thrombocytopenia is the most common hemostatic disorder in critically ill patients. The objective of this study was to describe the incidence, risk factors, and outcomes of thrombocytopenia in patients admitted to medical-surgical ICUs.

METHODS

Three thousand seven hundred forty-six patients in 67 centers were enrolled in a randomized trial in which unfractionated heparin was compared with low-molecular-weight heparin (LMWH) for thromboprophylaxis. Patients who had baseline platelet counts < 75 × 10(9)/L or severe coagulopathy at screening were excluded. We analyzed the risk of developing mild (100-149 × 10(9)/L), moderate (50-99 × 10(9)/L), and severe (< 50 × 109/L) thrombocytopenia during an ICU stay. We also assessed independent and time-varying predictors of thrombocytopenia and the effect of thrombocytopenia on major bleeding, transfusions, and death.

RESULTS

The incidences of mild, moderate, and severe thrombocytopenia were 15.3%, 5.1%, and 1.6%, respectively. The predictors of each category of thrombocytopenia were APACHE (Acute Physiology and Chronic Health Evaluation) II score, use of inotropes or vasopressors, and renal replacement therapy. The risk of moderate thrombocytopenia was lower in patients who received LMWH thromboprophylaxis but higher in surgical patients and in patients who had liver disease. Each category of thrombocytopenia was associated with subsequent bleeding and transfusions. Moderate and severe thrombocytopenia were associated with increased ICU and hospital mortality.

CONCLUSION

A high severity of illness, prior surgery, use of inotropes or vasopressors, renal replacement therapy, and liver dysfunction are associated with a higher risk of thrombocytopenia developing in the ICU, whereas LMWH thromboprophylaxis is associated with a lower risk. Patients who develop thrombocytopenia in the ICU are more likely to bleed, receive transfusions, and die.

Pivotal role of ADAMTS13 function in liver diseases

The liver is a major source of clotting and fibrinolytic proteins, and plays a central role in thrombo-regulation. Patients with advanced liver diseases tend to bleed because of reduced plasma levels of several clotting factors and thrombocytopenia, but they do also exhibit thrombotic complications. ADAMTS13 is a metalloproteinase, produced exclusively in hepatic stellate cells, and specifically cleaves highly multimeric von Willebrand factor (VWF). VWF plays a pivotal role in hemostasis and thrombosis, and its function is dependent on its multimeric state. Deficiency of ADAMTS13 results in accumulation of unusually large VWF multimers (UL-VWFM) in plasma, in turn induces platelet clumping or thrombi under high shear stress, followed by microcirculatory disturbances. Considering that UL-VWFM, the substrate of ADAMTS13, is produced in transformed vascular endothelial cells at sites of liver injury, decreased ADAMTS13 activity may be involved in not only sinusoidal microcirculatory disturbances, but also subsequent progression of liver injuries, eventually leading to multiorgan failure. This concept can be applied to the development or aggravation of liver diseases, including liver cirrhosis, alcoholic hepatitis, veno-occlusive disease, and adverse events after liver transplantation. These results promise to bring further understanding of the pathophysiology of liver diseases, and offer new insight for development of therapeutic strategies.

Platelet count decline: an early prognostic marker in critically ill patients with prolonged ICU stays

BACKGROUND

Thrombocytopenia is common in ICU patients. The objective of this study was to evaluate possible links between declining platelet counts early in the ICU stay and survival.

METHODS

All patients who were admitted to the ICU for at least 5 days and had no thrombocytopenia at the time of admission were included in the study. A multivariable logistic regression model, with hospital mortality as the outcome variable, was built.

RESULTS

We included 1,077 patients in the study. At ICU admission, the median platelet count was not significantly different in survivors (256 x 10(9) cells/L; interquartile range [IQR], 206 to 330 x 10(9) cells/L) and nonsurvivors (262 x 10(9) cells/L; 211 to 351 x 10(9) cells/L). Median simplified acute physiology scores II (SAPS II) at ICU admission was worse in nonsurvivors than in survivors (50 [IQR, 37 to 63] vs 37 [IQR, 27 to 48], respectively; p < 0.0001), as was the mean (+/- SD) sequential organ failure assessment (SOFA) score on day 3 (6.3 +/- 3.24 vs 4 +/- 2.8, respectively; p < 0.0001). Absolute platelet counts were lowest on day 4, but differed significantly between survivors and nonsurvivors only on day 7. Conversely, any percentage decline in platelet counts from 10 to 60% on day 4 was significantly associated with mortality. By multivariable analysis, a 30% decline in platelet count independently predicted death (odds ratio, 1.54; 95% confidence interval, 1.12 to 2.14; p = 0.008), in addition to increasing or stable SOFA scores from ICU admission to day 4, older age, male gender, ICU admission for coma, worse SAPS II score at ICU admission, transfer from another ward, and comorbidity.

CONCLUSION

In patients who spend > 5 days in the ICU and have normal platelet counts at ICU admission, a decline in platelet counts provides prognostic information. This parameter deserves to be included in new scoring systems.

La thrombopénie en réanimation chirurgicale: incidence, analyse des facteurs de risque et impact sur le pronostic

OBJECTIVE

To determine the incidence of thrombocytopenia in a surgical intensive care unit (ICU), the risk factors associated with it, and its effect on patient outcome.

METHODS

During a 6-month period, all patients admitted to the surgical intensive care unit were studied prospectively. The factors associated with thrombocytopenia were evaluated by univariate and multivariate analysis.

RESULTS

The study included 112 patients with a mean age of 50+/-18 years and a mean SAPS II (Simplified Acute Physiology Score) of 25+/-19: 41 developed thrombocytopenia (incidence=36,6%). Risk factors associated with it in the univariate analysis were high SAPS II, high organ dysfunction score, invasive intravascular catheters, sepsis, septic shock, and bleeding. After multivariate logistic regression analysis, only 3 independent risk factors remained for thrombocytopenia: bleeding (OR=11.9; 95% CI: 3.3-43.6; p<0.001), sepsis (OR=4.1; 95% CI: 1.3-11.7; p=0.013) and SAPS II>20 (OR=2.8; 95% CI: 1.0-7.8; p=0.042). Although mortality was higher in patients with than without thrombocytopenia , this difference was not statistically significant (41% versus 31%, p=0.26). Survival was similar in both groups, according to the Kaplan-Meier survival curve.

CONCLUSION

Thrombocytopenia is common in surgical ICUs. Bleeding and sepsis are the major risk factors. In this study, thrombocytopenia was not an independent factor of poor vital outcome in these critically ill patients.

Plasma ADAMTS13 activity may predict early adverse events in living donor liver transplantation: observations in 3 cases

A disintegrin-like and metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS13) is a metalloproteinase that specifically cleaves the multimeric von Willebrand factor (VWF). Deficiency of ADAMTS13 increases the unusually large VWF multimers (UL-VWFM), which leads to platelet clumping and/or thrombus formation, resulting in microcirculatory disturbance. We serially determined the activity of plasma ADAMTS13, together with VWF antigen (VWF:Ag) and UL-VWFM, in association with the development of early graft dysfunction in 3 liver transplant recipients and 4 patients with major hepatectomy as controls. In case 1, ADAMTS13 activity decreased markedly from 108% to less than 3% with concomitant thrombocytopenia on posttransplantation day 7, when acute rejection occurred. Simultaneously, UL-VWFM were detected. During the second episode of rejection, VWF:Ag increased to 368% with the appearance of UL-VWFM, while ADAMTS13 activity was as low as 18%, indicating an imbalance between a large amount of UL-VWFM and low activity of ADAMTS13. Administration of fresh frozen plasma (FFP) together with treatment for acute rejection resulted in an improvement of ADAMTS13 activity and disappearance of the UL-VWFM. In case 2, ADAMTS13 activity promptly decreased to 9% with thrombocytopenia on day 1, when ischemia-reperfusion injury occurred. Subsequently, the ADAMTS13 activity increased steadily without appearance of UL-VWFM, and the patient recovered uneventfully. ADAMTS13 activity decreased to 15% immediately after transplantation in case 3 as well. In contrast, ADAMTS13 activity never decreased below 20% in 4 patients with major hepatectomy as controls. In conclusion, these results indicate that the kinetics of ADAMTS13 and UL-VWFM could be good indicators of adverse events after liver transplantation. Our findings not only suggest a novel mechanism for thrombocytopenia, but also provide a useful tool for diagnosis of graft dysfunction in the early stage after transplantation.