Thrombocytopenia and prognosis in intensive care

Thrombocytopenia is associated with severe coronavirus disease 2019 (COVID-19) infections: A meta-analysis

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Platelet count can discriminate between severe and non-severe COVID-19 infections.

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Patients who did not survive have a significantly lower platelet count than survivors.

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Thrombocytopenia is associated with increased risk of severe disease.

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A substantial decrease in platelet count may be an indicator of worsening illness.

Background

Coronavirus disease 2019 (COVID-19) is a novel infectious disease with lack of established laboratory markers available to evaluate illness severity. In this study, we investigate whether platelet count could differentiate between COVID-19 patients with or without severe disease. Additionally, we evaluate if thrombocytopenia is associated with severe COVID-19.

Methods

An electronic search in Medline, Scopus and Web of Science was performed to identify studies reporting data on platelet count in COVID-19 patients. A meta-analysis was performed, with calculation of weighted mean difference (WMD) of platelet number in COVID-19 patients with or without severe disease and odds ratio (OR) of thrombocytopenia for severe form of COVID-19.

Results

Nine studies with 1779 COVID-19 patients, 399 (22.4%) with severe disease, were included in the meta-analysis. The pooled analysis revealed that platelet count was significantly lower in patients with more severe COVID-19 (WMD −31 × 10⁹/L; 95% CI, from −35 to −29 × 10⁹/L). A subgroup analysis comparing patients by survival, found an even lower platelet count was observed with mortality (WMD, −48 × 10⁹/L; 95% CI, −57 to −39 × 10⁹/L. In the four studies (n = 1427) which reported data on rate of thrombocytopenia, a low platelet count was associated with over fivefold enhanced risk of severe COVID-19 (OR, 5.1; 95% CI, 1.8–14.6).

Conclusions

Low platelet count is associated with increased risk of severe disease and mortality in patients with COVID-19, and thus should serve as clinical indicator of worsening illness during hospitalization.

Von Willebrand factor and ADAMTS13 impact on the outcome of Staphylococcus aureus sepsis

BACKGROUND

Previous clinical evidence correlates levels of von Willebrand factor (VWF) and its cleaving protease ADAMTS13 with outcome in septic patients. No previous studies addressed if VWF and ADAMTS13 affected the outcome of Staphylococcus aureus sepsis.

OBJECTIVES

We studied the role of VWF and ADAMTS13 in S. aureus sepsis both in patients and in mice.

METHODS

VWF levels and ADAMTS13 activity levels were measured in plasma samples from 89 S. aureus bacteremia patients by chemiluminescent assays and were correlated with clinical sepsis outcome parameters. In wild-type mice and mice deficient in VWF and ADAMTS13, we investigated the outcome of S. aureus sepsis and quantified bacterial clearance and organ microthrombi.

RESULTS

In patients with S. aureus bloodstream infections, high VWF levels and low ADAMTS13 activity levels correlated with disease severity and with parameters of inflammation and disseminated intravascular coagulation. In septic mice, VWF deficiency attenuated mortality, whereas ADAMTS13 deficiency increased mortality. Bacterial clearance was enhanced in VWF-deficient mice. The differences in mortality for the studied genotypes were associated with differential loads of organ microthrombi in both liver and kidneys.

CONCLUSIONS

In conclusion, this study reports the consistent relation of VWF, ADAMTS13 and their ratio to disease severity in patients and mice with S. aureus sepsis. Targeting VWF multimers and/or the relative ADAMTS13 deficiency that occurs in sepsis should be explored as a potential new therapeutic target in S. aureus endovascular infections.

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.

The association of coagulation indicators with in-hospital mortality and 1-year mortality of patients with sepsis at ICU admissions: A retrospective cohort study

BACKGROUND

Coagulation activation is the host's response to pathogens during sepsis and is considered to be one of the reasons for tissue damage and multiple organ failure. This study is designed to evaluate whether the alterations of coagulation indicators are related to in-hospital mortality and 1-year mortality of patients with sepsis.

METHOD

Data of all 2258 patients were extracted from the database Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC III). The relationship between the in-hospital mortality of patients with sepsis and coagulation indicators was analyzed with a receiver operating characteristic (ROC) curve analysis and logistic regression model. Effects of coagulation indicators on patients' 1-year mortality were determined by using a Cox hazard regression model, and clinical experience or quintiles were used to classify the activated partial thromboplastin time (APTT) to determine the cutoff values to explore segmentation effects.

RESULT

International normalized ratio (INR) was positively associated with hospital mortality of patients with sepsis after adjusting confounders with an odds ratio (OR) of 1.86 [95% confidence interval (CI), 1.37-2.52], and a hazard ratio (HR) of 1.465[95%CI(1.24-1.74)] for 1-year mortality, respectively. 1-year mortality of patients with sepsis demonstrated a U-shaped relationship with APTT, ranging from 25 to 37, indicating the lowest risk. The adjusted HR (95% CI) values for 1-year mortality of septic patients with risk values <25 and >37 were 1.493 (1.02, 2.19) and 1.379 (1.06, 1.79), respectively.

CONCLUSION

Increased INR in critically ill septic patients is related to greater in-hospital mortality and 1-year mortality. A U-shaped relationship was found between APTT and 1-year mortality of patients with sepsis.

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.

Thrombocytopenia in the Intensive Care Unit

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

Impact of Chronic Thrombocytopenia on Outcomes After Transcatheter Valvular Intervention and Cardiac Devices Implantation (From a National Inpatient Sample)

To evaluate the impact of chronic thrombocytopenia (cTCP) on outcomes of transcatheter valvular procedures such as aortic valve implantation (TAVI), MitraClip, permanent pacemaker (PPM), implantable-cardioverter defibrillator (ICD), cardiac resynchronization therapy (CRT), left atrial appendage closure, and pericardiocentesis. Impact of cTCP on clinical outcomes following TAVI, Mitraclip, PPM, ICD, CRT, left atrial appendage closure, and pericardiocentesis procedures is not well described. Utilizing the National Inpatient Sample and (ICD-9-CM) procedural codes, we evaluated patients (age ≥18 years) who underwent these procedures, from January 1, 2009 to December 31, 2014, with or without cTCP as a chronic condition variable indicator. Propensity score matching model implemented to derive 2 matched groups. Propensity score matching created 47,292 and 47,351 hospitalizations matched pairs with and without cTCP, respectively. Patients with cTCP were older (mean age, 74.27 vs 72.26 years; absolute standardized differences [ASD] = 15.6) and less likely to be female (36.76% vs 43.74%, ASD = -14.31). They experienced higher in-hospital mortality (3.0% vs 2.0%; odds ratio [OR], 1.53; 95% confidence interval [CI], 1.27 to 1.83) and higher odds of vascular injury requiring surgery (2.63% vs 1.10%; OR, 2.43; 95% CI, 1.93 to 3.05). Postoperative hematoma and bleeding were 2-fold higher (4.57% vs 2.24%; OR, 2.08; 95% CI, 1.77 to 2.45) and 3-fold higher (6.34% vs 2.45%; OR, 2.69; 95% CI, 2.31 to 3.13) respectively among cTCP patients. They had greater health-care cost ($47,163 vs $35,763, p <0.0001) and longer hospital stay (mean 9.26 days vs 6.84 days, p <0.0001). In conclusion, cTCP patients had higher risk of complications after TAVI, MitraClip, PPM, ICD, CRT, left atrial appendage closure, and pericardiocentesis, including a 1.5-fold increased risk of in-hospital mortality.

Post-transfusion platelet responses in critically ill cancer patients with hypoproliferative thrombocytopenia

BACKGROUND

Platelet transfusion is aimed at increasing platelet counts to prevent or treat bleeding. Critically ill cancer patients with hypoproliferative thrombocytopenia are high consumers of blood products. We herein described their post-transfusion platelet responses in the intensive care unit (ICU) and analyzed the determinants of poor post-transfusion increments.

STUDY DESIGN AND METHODS

This was a single-center 9-year (2009-2017) retrospective observational study. Patients with malignancies and presumed or proven hypoproliferative thrombocytopenia who had received at least one platelet transfusion in the ICU were included. Poor post-transfusion platelet increments were defined as body surface-adjusted corrected count increment (CCI) <7, or alternatively as weight-adjusted platelet transfusion recovery (PTR) <0.2. Patients were deemed refractory to platelet transfusions when two consecutive ABO-compatible transfusions resulted in poor platelet increments.

RESULTS

A total of 1470 platelet transfusions received by 326 patients were analyzed. Indications for platelet transfusions were distributed into prophylactic (44.5%), peri-procedural (18.1%) and therapeutic (37.4%). Regardless of indications, 54.6% and 55.4% of transfusion episodes were associated with a CCI <7 or a PTR <0.2. Factors independently associated with poor post-transfusion increments were lower body mass index, spleen enlargement, concurrent severity of clinical condition, fever ≥39°C, antibiotic therapy and increased storage duration of platelet concentrates. Eventually, 48 patients developed refractoriness to platelet transfusion, which was associated increased incidence of bleeding events.

CONCLUSION

Platelet transfusions are often associated with poor increments in critically ill cancer patients with hypoproliferative thrombocytopenia. The findings suggest amenable interventions to improve the platelet transfusion practices in this setting.

Thrombocytopenia Impairs Host Defense Against Burkholderia pseudomallei (Melioidosis)

Background

Infection with the gram-negative bacillus Burkholderia pseudomallei (melioidosis) is an important cause of pneumosepsis in Southeast Asia and has a mortality of up to 40%. We aimed to assess the role of platelets in the host response against B. pseudomallei infection.

Methods

Association between platelet counts and mortality was determined in 1160 patients with culture-proven melioidosis. Mice treated with (low- or high-dose) platelet-depleting antibody were inoculated intranasally with B. pseudomallei and killed. Additional studies using functional glycoprotein Ibα-deficient mice were conducted.

Results

Thrombocytopenia was present in 31% of patients at admission and predicted mortality in melioidosis patients even after adjustment for confounders. In our murine-melioidosis model, platelet counts decreased, and mice treated with a platelet-depleting antibody showed enhanced mortality and higher bacterial loads compared to mice with normal platelet counts. Low platelet counts had a modest impact on early-pulmonary neutrophil influx. Reminiscent of their role in hemostasis, platelet depletion impaired vascular integrity, resulting in early lung bleeding. Glycoprotein Ibα-deficient mice had reduced platelet counts during B. pseudomallei infection together with an impaired local host defense in the lung.

Conclusions

Thrombocytopenia predicts mortality in melioidosis patients and, during experimental melioidosis, platelets play a protective role in both innate immunity and vascular integrity.

Platelet biology of the rapidly failing lung

Acute respiratory distress syndrome (ARDS) is characterized by a rapid-onset respiratory failure with a mortality rate of approximately 40%. This physiologic inflammatory process is mediated by disruption of the alveolar-vascular interface, leading to pulmonary oedema and impaired oxygen exchange, which often warrants mechanical ventilation to increase survival in the acute setting. One of the least understood aspects of ARDS is the role of the platelets in this process. Platelets, which protect vascular integrity, play a pivotal role in the progression and resolution of ARDS. The recent substantiation of the age-old theory that megakaryocytes are found in the lungs has rejuvenated interest in and raised new questions about the importance of platelets for pulmonary function. In addition to primary haemostasis, platelets provide a myriad of inflammatory functions that are poised to aid the innate immune system. This review focuses on the evidence for regulatory roles of platelets in pulmonary inflammation, with an emphasis on two receptors, CLEC-2 and TLT-1. Studies of these receptors identify novel pathways through which platelets may regulate vascular integrity and inflammation in the lungs, thereby influencing the development of ARDS.

Prophylactic Platelet Transfusions for Critically Ill Patients With Thrombocytopenia: A Single-Institution Propensity-Matched Cohort Study

BACKGROUND

Thrombocytopenia is frequently encountered in critically ill patients, often resulting in prophylactic transfusion of platelets for the prevention of bleeding complications. However, the efficacy of this practice remains unclear. The objective of this study was to determine the relationship between prophylactic platelet transfusion and bleeding complications in critically ill patients.

METHODS

This is a retrospective cohort study of adults admitted to surgical, medical, or combined medical-surgical intensive care units (ICUs) at a single academic institution between January 1, 2009, and December 31, 2013. Inclusion criteria included age ≥18 years and a platelet count measured during ICU admission. Propensity-matched analyses were used to evaluate associations between prophylactic platelet transfusions and the outcomes of interest with a primary outcome of red blood cell transfusion in the ensuing 24 hours and secondary outcomes of ICU and hospital-free days and changes in sequential organ failure assessment scores.

RESULTS

A total of 40,693 patients were included in the investigation with 3227 (7.9%) receiving a platelet transfusion and 1065 (33.0%) for which platelet transfusion was prophylactic in nature. In propensity-matched analyses, 994 patients with prophylactic platelet transfusion were matched to those without a transfusion. Patients receiving prophylactic platelets had significantly higher red blood cell transfusion rates (odds ratio 7.5 [5.9-9.5]; P < .001), fewer ICU-free days (mean [standard deviation] 20.8 [9.1] vs 22.7 [8.3] days; P = .004), fewer hospital-free days (13.0 [9.7] vs 15.8 [9.4] days; P < .001), and less improvement in sequential organ failure assessment scores (mean decrease of 0.2 [3.6] vs 1.8 [3.3]; P < .001) in the subsequent 24 hours. These findings appeared robust, persisting in multiple predefined sensitivity analyses.

CONCLUSIONS

Prophylactic administration of platelets in the critically ill was not associated with improved clinical outcomes, though residual confounding may exist. Further investigation of platelet transfusion strategies in this population is warranted.

Kinetics of mean platelet volume predicts mortality in patients with septic shock

Introduction

Thrombocytopenia is well recognized as a poor prognosis sign associated with increased mortality and prolonged Intensive Care Unit (ICU) stay, particularly in septic patients. Mean platelet volume (MPV) could represent a relevant predictive marker of mortality. Here we investigated whether MPV kinetics during the first 15 days after hospital admission has a potential prognostic value for clinical outcome in septic shock.

Methods

We performed a retrospectively analysis of a cohort of 301 septic patients admitted in ICU. Three-month mortality was the primary endpoint. The prognostic value of the covariates of interest was ascertained by multidimensional analysis. We proposed a classification and regression trees analysis to predict survival probability.

Results

MPV kinetics was significantly different between 90-day survivors and non-survivors when followed during 15 days (except on day 3). 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality (Hazard Ratio (HR) 3.796, 95% Confidence Interval (CI) [1.96–7.35], p = 0.0001) in multivariate analysis. Base excess on day 4 <1.9mmol/L was also a predictive factor of mortality (HR 2.972, 95%CI [1.38–6.40], p = 0.0054.

Conclusion

MPV increase during the first 15 days after ICU admission in non-survivors was observed during septic shock and 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality. This could be explained by the emergent response to acute platelet loss during septic shock, leading to megakaryocyte rupture to produce new but potentially immature platelets in the circulation. Therefore, continuous monitoring of MPV may be a useful parameter to stratify mortality risk in septic shock.

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.

Platelets in Host Defense: Experimental and Clinical Insights

Platelets are central players in thrombosis and hemostasis but are increasingly recognized as key components of the immune system. They shape ensuing immune responses by recruiting leukocytes, and support the development of adaptive immunity. Recent data shed new light on the complex role of platelets in immunity. Here, we summarize experimental and clinical data on the role of platelets in host defense against bacteria. Platelets bind, contain, and kill bacteria directly; however, platelet proinflammatory effector functions and cross-talk with the coagulation system, can also result in damage to the host (e.g., acute lung injury and sepsis). Novel clinical insights support this dichotomy: platelet inhibition/thrombocytopenia can be either harmful or protective, depending on pathophysiological context. Clinical studies are currently addressing this aspect in greater depth.

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.

Complete blood count in acute kidney injury prediction: a narrative review

Acute kidney injury (AKI) is a complex syndrome defined by a decrease in renal function. The incidence of AKI has raised in the past decades, and it is associated with negative impact in patient outcomes in the short and long term. Considering the impact of AKI on patient prognosis, research has focused on methods to assess patients at risk for developing AKI, diagnose subclinical AKI, and on prevention and treatment strategies, for which it is crucial an understanding of pathophysiology the of AKI. In this review, we discuss the use of easily available parameters found in a complete blood count to detect patients at risk for developing AKI, to provide an early diagnosis of AKI, and to predict associated patient outcomes.

Platelets in Sepsis: An Update on Experimental Models and Clinical Data

Beyond their important role in hemostasis, platelets play a crucial role in inflammatory diseases. This becomes apparent during sepsis, where platelet count and activation correlate with disease outcome and survival. Sepsis is caused by a dysregulated host response to infection, leading to organ dysfunction, permanent disabilities, or death. During sepsis, tissue injury results from the concomitant uncontrolled activation of the complement, coagulation, and inflammatory systems as well as platelet dysfunction. The balance between the systemic inflammatory response syndrome (SIRS) and the compensatory anti-inflammatory response (CARS) regulates sepsis outcome. Persistent thrombocytopenia is considered as an independent risk factor of mortality in sepsis, although it is still unclear whether the drop in platelet count is the cause or the consequence of sepsis severity. The role of platelets in sepsis development and progression was addressed in different experimental in vivo models, particularly in mice, that represent various aspects of human sepsis. The immunomodulatory function of platelets depends on the experimental model, time, and type of infection. Understanding the molecular mechanism of platelet regulation in inflammation could bring us one step closer to understand this important aspect of primary hemostasis which drives thrombotic as well as bleeding complications in patients with sterile and infectious inflammation. In this review, we summarize the current understanding of the contribution of platelets to sepsis severity and outcome. We highlight the differences between platelet receptors in mice and humans and discuss the potential and limitations of animal models to study platelet-related functions in sepsis.

Platelets Are Critical Key Players in Sepsis

Host defense against infection is based on two crucial mechanisms: the inflammatory response and the activation of coagulation. Platelets are involved in both hemostasis and immune response. These mechanisms work together in a complex and synchronous manner making the contribution of platelets of major importance in sepsis. This is a summary of the pathophysiology of sepsis-induced thrombocytopenia, microvascular consequences, platelet-endothelial cells and platelet–pathogens interactions. The critical role of platelets during sepsis and the therapeutic implications are also reviewed.

P2X1 receptor blockers reduce the number of circulating thrombocytes and the overall survival of urosepsis with haemolysin-producing Escherichia coli

Urosepsis is a severe condition often caused by Escherichia coli that spontaneously have ascended the urinary tract to the kidneys causing pyelonephritis and potentially bacteraemia. The number of sepsis cases has been steadily increasing over the last decades, and there are still no specific, molecular supportive therapies for sepsis to supplement antibiotic treatment. P2X₁ receptors are expressed by a number of immune cells including thrombocytes, which presently have been established as an important player in the acute immune response to bacterial infections. P2X₁ receptor-deficient mice have been shown to be relatively protected against urosepsis, with markedly reduced levels of circulating proinflammatory cytokines and intravascular coagulation. However, here we show that continuous intravenous infusion with P2X₁ receptor antagonist markedly accelerates development of a septic response to induced bacteraemia with uropathogenic E. coli. Mice exposed to the P2X₁ receptor antagonists die very early with haematuria, substantially elevated plasma levels of proinflammatory cytokines, massive intravascular coagulation and a concomitant reduction in circulating thrombocytes. Interestingly, infusion of P2X₁ receptor antagonists causes a marked acute reduction in circulating thrombocytes and a higher number of bacteria in the blood. These data support the notion that the number of functional thrombocytes is important for the acute defence against bacteria in the circulation and that the P2X₁ receptor potentially could be essential for this response.

An evaluation of clinical inflammatory and coagulation markers in patients with sepsis: a pilot study

Aim

Presepsin values could assist early diagnosis and prognosis of sepsis. In sepsis, prognosis is determined according to multiple organ dysfunction, where coagulopathy is common and associated with prognosis. This study aimed to determine the correlation between presepsin value trend and prognosis, and investigate coagulation abnormality in sepsis.

Methods

We retrospectively examined 18 intensive care unit patients diagnosed with sepsis whose presepsin values at admission were ≥500 ng/mL. If presepsin values had decreased ≥50% on hospital day 6, compared to admission values, the patient was allocated into a decreased presepsin group.

Results

Presepsin values in non-survivors with sepsis were significantly higher than in survivors on day 6 (P = 0.022). No significant differences in procalcitonin or C-reactive protein were identified between survivors and non-survivors, and platelet counts were significantly lower in non-survivors on days 0, 3, and 6 (P = 0.001, P < 0.001, and P = 0.001, respectively). The 90-day mortality rate in a decreased presepsin group significantly improved, even when presepsin values were high on admission (P = 0.012). Platelet counts were significantly lower on all hospital days in the non-decreased presepsin group.

Conclusion

Fifty percent decrease in presepsin levels could be a useful prognostic predictor of sepsis. Larger studies are required to confirm our findings.

Delayed Antibiotic Therapy and Organ Dysfunction in Critically Ill Septic Patients in the Emergency Department

Background: We investigated the effect of antibiotic timing on outcomes based on changes in surrogate markers of organ failure, including platelet, serum bilirubin, serum creatinine levels, and the PaO₂/FiO₂ (P/F) ratio. Methods: This was a single-center, retrospective observational study of critically ill septic patients who presented to the emergency department (ED). The study period extended from August 2008 to September 2016. The primary outcomes included changes in platelet, serum bilirubin, serum creatinine levels, and the P/F ratio (δ-platelet, δ-serum bilirubin, δ-serum creatinine, and δ-P/F ratio were calculated as values measured on Day 3; values measured at ED enrollment). A multivariable linear regression model was developed to assess variables related to outcomes (δ-platelet, δ-serum bilirubin, δ-serum creatinine, and δ-P/F ratio). Results: We analyzed 1784 patients who met the inclusion criteria. The overall 28-day mortality was 14% (n = 256/1784). On multivariable linear regression analysis, the hourly delay in antibiotic therapy was significantly associated with a decrease in δ-platelet count (coefficient, −1.741; standard error, 0.740; p = 0.019), and an increase in δ-serum bilirubin (coefficient, 0.054; standard error, 0.021; p = 0.009). In contrast, it was not associated with δ-creatinine (coefficient, 0.008; standard error, 0.010; p = 0.434) or the δ-P/F ratio (coefficient, −0.797; standard error, 1.858; p = 0.668). Conclusion: The hourly delay of antibiotic therapy was associated with decreased platelet count and increased serum bilirubin concentration in critically ill septic patients during the first three days of ED admission.

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

BACKGROUND

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

METHODS

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

CONCLUSION

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

Thrombocytopenia After Transcatheter Valve-in-Valve Implantation: Prognostic Marker or Mere Finding?

Objective

To analyze the behavior of platelets after transcatheter valve-in-valve implantation for the treatment of degenerated bioprosthesis and how they correlate with adverse events upon follow-up.

Methods

Retrospective analysis of 28 patients who received a valve-in-valve implant, 5 in aortic, 18 in mitral and 5 in tricuspid positions. Data were compared with 74 patients submitted to conventional redo valvular replacements during the same period, and both groups' platelet curves were analyzed. Statistical analysis was conducted using the IBM SPSS Statistics(r) 20 for Windows.

Results

All patients in the valve-in-valve group developed thrombocytopenia, 25% presenting mild (<150.000/µL), 54% moderate (<100.000/µL) and 21% severe (<50.000/µL) thrombocytopenia. The platelet nadir was on the 4^th postoperative day for aortic ViV, 2^nd for mitral and 3^rd for tricuspid patients, with the majority of patients recovering regular platelet count. However, the aortic subgroup comparison between valve-in-valve and conventional surgery showed a statistically significant difference from the 7^th day onwards, where valve-in-valve patients had more severe and longer lasting thrombocytopenia. This, however, did not translate into a higher postoperative risk. In our study population, postoperative thrombocytopenia did not correlate with greater occurrence of adverse outcomes and only normal preoperative platelet count could significantly predict a postoperative drop >50%.

Conclusion

Although thrombocytopenia is an extremely common finding after valve-in-valve procedures, the degree of platelet count drop did not correlate with greater incidence of postoperative adverse outcomes in our study population.

Thrombocytopenia in Septic Shock Patients—A Prospective Observational Study of Incidence, Risk Factors and Correlation with Clinical Outcome

The objectives of the study were to study the incidence of various degrees of severity of thrombocytopenia in septic shock, the risk factors for its development and the correlation with clinical outcome. Complete blood counts, chemistry panel, arterial lactate, serum cortisol, APACHE II score, logistic organ dysfunction score and SOFA score were determined in 69 septic shock patients within 24 hours of admission or onset of septic shock. We followed the patients until they died or for six months to determine the mortality rate. The incidence of thrombocytopenia in our study group was 55%. Patients with thrombocytopenia had significantly higher serum creatinine, SOFA score, vasopressor requirement, lower PaO2/FiO2 ratio and higher mortality than those without thrombocytopenia (P <0.05). Higher SOFA score, low PaO2/FiO2 ratio and high vasopressor dose were independent risk factors for development of thrombocytopenia. The presence of thrombocytopenia had significant correlation with SOFA score (P=0.008). On receiver-operator characteristic curve analysis, platelet count was found to be predictive of increased mortality (area under curve=0.56). Thrombocytopenic patients had 1.4 times the risk of mortality and lower survival probability at six months (log rank test P=0.03). In conclusion, thrombocytopenia is common in septic shock and is associated with worse clinical outcome. Higher SOFA score, low PaO2/FiO2 ratio and high vasopressor dose are independent risk factors for development of thrombocytopenia in septic shock.

Thrombocytopenia in the intensive care unit

Thrombocytopenia is a frequent finding in intensive care unit especially among adults and medical ICU patients. Thrombocytopenia is defined as a platelet count less than 100×10⁹/l in ICU setting. Platelets are made in the bone marrow from megakaryocytes. Although not fully understood, proplatelets transform into platelets in the lung. The body tries to maintain platelet count relatively constant throughout life. Pathophysiology of thrombocytopenia can be defined by hemodilution, elevated levels of platelet consumption, compromise of platelet production, increased platelet sequestration and increased platelet destruction. Unlike in other situations, absolute platelet count alone does not provide sufficient data in characterizing thrombocytopenia in ICU patients. In such cases, the time course of changes in platelet count is also pivotal. The dynamics of platelet count decrease vary considerably between different ICU patient populations including trauma, major surgery and minor surgery/medical conditions. There are strong evidences available that delay in platelet count restoration in ICU patients is an indicator of a bad outcome.

Platelet-derived TLT-1 is a prognostic indicator in ALI/ARDS and prevents tissue damage in the lungs in a mouse model

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) affect >200 000 individuals yearly with a 40% mortality rate. Although platelets are implicated in the progression of ALI/ARDS, their exact role remains undefined. Triggering receptor expressed in myeloid cells (TREM)-like transcript 1 (TLT-1) is found on platelets, binds fibrinogen, and mediates clot formation. We hypothesized that platelets use TLT-1 to manage the progression of ALI/ARDS. Here we retrospectively measure plasma levels of soluble TLT-1 (sTLT-1) from the ARDS Network clinical trial and show that patients whose sTLT-1 levels were >1200 pg/mL had nearly twice the mortality risk as those with <1200 pg/mL (P < .001). After correcting for confounding factors such as creatinine levels, Acute Physiology And Chronic Health Evaluation III scores, age, platelet counts, and ventilation volume, sTLT-1 remains significant, suggesting that sTLT-1 is an independent prognostic factor (P < .0001). These data point to a role for TLT-1 during the progression of ALI/ARDS. We use a murine lipopolysaccharide-induced ALI model and demonstrate increased alveolar bleeding, aberrant neutrophil transmigration and accumulation associated with decreased fibrinogen deposition, and increased pulmonary tissue damage in the absence of TLT-1. The loss of TLT-1 resulted in an increased proportion of platelet-neutrophil conjugates (43.73 ± 24.75% vs 8.92 ± 2.4% in wild-type mice), which correlated with increased neutrophil death. Infusion of sTLT-1 restores normal fibrinogen deposition and reduces pulmonary hemorrhage by 40% (P ≤ .001) and tissue damage by 25% (P ≤ .001) in vivo. Our findings suggest that TLT-1 uses fibrinogen to govern the transition between inflammation and hemostasis and facilitate controlled leukocyte transmigration during the progression of ARDS.

Spectrum of Diseases/conditions Exhibiting Hemostatic Abnormalities in Patients Admitted to a Medical Intensive Care Unit of a Tertiary Care Hospital

Background and Aims:

In a medical intensive care unit (MICU), many patients develop hemostatic abnormalities, ranging from abnormal clotting tests to frank bleeding. The aim of this study was to assess the etiology of diseases that present with bleeding, its common bleeding manifestations, incidence, MICU stay, mortality, and transfusion requirements in an Indian setup and also to assess if the Acute Physiology and Chronic Health Evaluation II (APACHE II) score can be used as a predictor for blood transfusion requirements.

Materials and Methods:

Between July 2013 and August 2014, 200 patients with clinically significant bleeding admitted in the MICU were prospectively evaluated. Detailed history, examination, laboratory investigations, APACHE II score, and requirement of blood products were also noted. The endpoints were discharge or death.

Results:

The spectrum of diseases that presented with bleeding was 47 patients with malaria (23.5%) followed by 36 acute undifferentiated febrile illness (18.0%), 33 dengue (16.5%), 30 leptospirosis (15.0%), 31 acute fulminant hepatitis (15.5%), 14 sepsis (7.0%), and the rest nine miscellaneous causes. The most common bleeding manifestation observed was hematuria in 62/200 (31%). Among the patients studied, 126 expired (63%) and 74 survived (37%). Of the 200 patients, 48/200 (24%) received packed cells, 78/200 (39%) fresh frozen plasma, and 82/200 (41%) platelets.

Conclusions:

Tropical diseases formed the majority of admissions with bleeding manifestations. Thrombocytopenia is an important marker to predict mortality and also has a significant association with MICU stay. APACHE II score was found to be a good predictor of blood transfusion requirements.

Platelet number and graft function predict intensive care survival in allogeneic stem cell transplantation patients

Despite significant advances in the treatment of complications requiring intensive care unit (ICU) admission, ICU mortality remains high for patients after allogeneic stem cell transplantation. We evaluated the role of thrombocytopenia and poor graft function in allogeneic stem cell recipients receiving ICU treatments along with established prognostic ICU markers in order to identify patients at risk for severe complications. At ICU admission, clinical and laboratory data of 108 allogeneic stem cell transplanted ICU patients were collected and retrospectively analyzed. Platelet counts (≤ 50,000/μl, p < 0.0005), hemoglobin levels (≤ 8.5 mg/dl, p = 0.019), and leukocyte count (≤ 1500/μl, p = 0.025) along with sepsis (p = 0.002) and acute myeloid leukemia (p < 0.0005) correlated significantly with survival. Multivariate analysis confirmed thrombocytopenia (hazard ratio (HR) 2.79 (1.58-4.92, 95% confidence interval (CI)) and anemia (HR 1.82, 1.06-3.11, 95% CI) as independent mortality risk factors. Predominant ICU diagnoses were acute respiratory failure (75%), acute kidney injury (47%), and septic shock (30%). Acute graft versus host disease was diagnosed in 42% of patients, and 47% required vasopressors. Low platelet (≤ 50,000/μl) and poor graft function are independent prognostic factors for impaired survival in critically ill stem cell transplanted patients. The underlying pathophysiology of poor graft function is not fully understood and currently under investigation. High-risk patients may be identified and ICU treatments stratified according to allogeneic stem cell patients' individual risk profiles. In contrast to previous studies involving medical or surgical ICU patients, the fraction of thrombocytopenic patients was larger and low platelets were a better differentiating factor in multivariate analysis than any other parameter.

Valuable prognostic indicators for severe burn sepsis with inhalation lesion: age, platelet count, and procalcitonin

Background

Severe burn sepsis can lead to high mortality. We explored the valuable prognostic indicators for severe burn sepsis with inhalation lesion.

Methods

Thirty-eight severe burn patients with sepsis who were admitted to the Third Affiliated Hospital of Soochow University from August 2014 to December 2017 were retrospectively analyzed. Among them, 22 patients were assigned to the death group and 16 patients to the survival group. Their general information, vital signs, and blood index including serum procalcitonin (PCT) and C-reactive protein (CRP) levels at admission, diagnosis of sepsis, and 1-week post-diagnosis of sepsis were compared.

Results

Patients in the death group were older and had lower platelet count (PLT) at diagnosis of sepsis and 1-week post-diagnosis as well as higher PCT level at 1-week post-diagnosis than patients in the survival group (all p < 0.05). According to receiver operating characteristic (ROC) curves, the above four indicators could be used to predict the prognosis, and the area under the curve (AUC) of PLT at diagnosis and 1-week post-diagnosis was larger (0.888 and 0.911), and PLT at diagnosis had the highest sensitivity and specificity (0.842 and 0.937). In addition, these patients were divided into two groups by the optimal cutoff age of 38 years. According to multivariate logistic regression analysis and COX regression analysis, only age group and PLT at diagnosis were statistically significant (all p < 0.05). The risk of death in the older group was 28 times higher than that in the younger group, and the risk of death increased by 3% for each unit reduction in PLT at diagnosis. Moreover, age group was an independent factor affecting the patients’ survival (β = − 1.370, p = 0.026). Considering the survival time after sepsis, the mortality risk was lower for patients in the older group than for patients in the younger group (hazard ratio (HR) = 0.254, 95% confidence interval (CI) 0.076–0.851).

Conclusion

Age, PLT at diagnosis of sepsis, and 1-week post-diagnosis as well as PCT level at 1-week post-diagnosis are indicators for the evaluation of prognosis of severe burn sepsis with inhalation lesion. Among them, PLT at diagnosis has the greatest prognostic value. In addition, age can predict the patients’ mortality and survival time after sepsis.

Biomarkers of disseminated intravascular coagulation in pediatric intensive care unit in Thailand

INTRODUCTION

Disseminated intravascular coagulation (DIC) is a systemic activation of hemostatic system caused by several causes. Biomarkers including antithrombin (AT), protein C (PC), and thrombomodulin (TM) were reported as the additional markers for DIC in adults. This study aimed to determine the association between biomarkers among patients with overt DIC (ODIC) and nonovert DIC (NDIC) in children in PICU.

METHODS

We enrolled 103 subjects, aged 1 month-18 years, who were admitted to PICU at Chiang Mai University (CMU) Hospital >24 hours with underlying conditions predisposing to DIC were enrolled. Biomarkers were tested after 24 hours of admission. Subject who had NDIC on the 1^st investigations would have other tests on days 3-5 of admission.

RESULTS

The incidence of ODIC by the International Society on Thrombosis and Hemostasis (ISTH) DIC score was found 24%. The bleeding, thrombosis, and death were significantly higher in ODIC group (P < 0.05). Mean levels of AT and PC in ODIC group were significantly different from NDIC one (66.9% vs 79.9%, P < 0.001 and 46.1% vs 59.2%, P = 0.004, respectively) while mean level of TM was not different between two groups. Adding AT to DIC score was better than the original score for predict mortality [area under curve (AUC) = 0.662 vs AUC = 0.65] and bleeding (AUC = 0.751 vs AUC = 0.732).

CONCLUSIONS

ODIC is prevalent among critically ill children. Adverse outcomes were more commonly found in children with ODIC. AT and PC levels after 24 hours of PICU admission seem to be the useful biomarkers for ODIC in PICU.

The cut-off levels of procalcitonin and C-reactive protein and the kinetics of mean platelet volume in preterm neonates with sepsis

Background

Sepsis is a leading cause of morbidity and mortality among newborns. C-reactive protein (CRP) and procalcitonin (PCT) have some limitations in the diagnosis of preterm neonatal sepsis. In this study, the cut-offs of PCT and CRP, and the efficacy of mean platelet volume (MPV) were investigated.

Methods

We identified key demographic details and compared laboratory values between preterm infants with early onset and late onset neonatal sepsis (EONS/LONS) retrospectively. Blood samples were collected within the first few hours of the onset of clinical sepsis (CRP 1, PCT 1, MPV 1) and were repeated after 24 h (CRP 2, PCT 2, MPV 2). The optimal cut-offs for CRP, PCT and MPV were determined using receiver operating characteristic (ROC) analysis. Furthermore, pairwise comparisons of ROC curves were made to evaluate the performances of these tests.

Results

In EONS, the cut-off of CRP 1 was 2.6 mg/L, the sensitivity, specificity, PPV and NPV were 80.6, 83.0, 67.5 and 90.7%, respectively (p < 0.001). At a PCT 1 cut-off of 1.1 ng/mL, the sensitivity, specificity, PPV and NPV were 78.6, 81.2, 64.7 and 89.6%, respectively (p < 0.001). The sensitivity, specificity, PPV, and NPV of the CRP 1 cut-off of 3.6 mg/L for LONS were 78.3, 87.4, 74.8, and 89.4%, respectively. At a PCT 1 cut-off of 5.2 ng/mL, the sensitivity, specificity, PPV and NPV were 58.5, 95.5, 86.1, and 82.9% respectively. For proven sepsis, the cut-off of CRP 1 was 7.0 mg/L with a 76.5% sensitivity, 98.2% specificity, 94.9% PPV and 90.5% NPV (p < 0.001). At a PCT 1 cut-off of 1.36 ng/mL, the sensitivity, specificity, PPV and NPV were 90.8, 83.4, 70.6 and 94.4%, respectively (p < 0.001). In each subgroup, other than EONS, the performances of CRP 1 and PCT 1 measurements were found to be statistically higher than MPV 1. CRP 2 cut-off levels of LONS group and proven sepsis group were found to be lower than the initial values.

Conclusions

Optimal cut-off levels of CRP 1 and PCT 1 may differ in preterm sepsis subgroups. The diagnostic performances of CRP 1 and PCT 1 didn’t differ however, they were more efficacious than MPV.

Platelet Depletion Impairs Host Defense to Pulmonary Infection with Pseudomonas aeruginosa in Mice

Platelets have been implicated in pulmonary inflammatory cell recruitment after exposure to allergic and nonallergic stimuli, but little is known about the role of platelets in response to pulmonary infection with Pseudomonas aeruginosa. In this study, we have investigated the impact of the experimental depletion of circulating platelets on a range of inflammatory and bacterial parameters, and their subsequent impact on mortality in a murine model of pulmonary infection with P. aeruginosa. P. aeruginosa infection in mice induced a mild, but significant, state of peripheral thrombocytopenia in addition to pulmonary platelet accumulation. Increased platelet activation was detected in infected mice through increased levels of the platelet-derived mediators, platelet factor-4 and β-thromboglobulin, in BAL fluid and blood plasma. In mice depleted of circulating platelets, pulmonary neutrophil recruitment was significantly reduced 24 hours after infection, whereas the incidence of systemic dissemination of bacteria was significantly increased compared with non-platelet-depleted control mice. Furthermore, mortality rates were increased in bacterial-infected mice depleted of circulating platelets. This work demonstrates a role for platelets in the host response toward a gram-negative bacterial respiratory infection.

Platelet dysfunction in critically ill patients

: Thrombelastography Platelet Mapping (TEG-PM) allows for measurement of maximal potential clot strength (MA) and strength from stimulation of arachidonic acid (MA-AA) and adenosine disphosphate (MA-ADP) receptors. This study was conducted to assess degree of platelet dysfunction in critically ill adult patients. A retrospective study of critically ill, adult, nontrauma patients in a medical/surgical ICU was conducted from August 2013 to September 2014. All patients who underwent TEG-PM were enrolled. Patients with intracerebral hemorrhage, following cardiac surgery, or without an APACHE II score were excluded. Patients were divided into those with and without aspirin use. Demographics, APACHE II score, and laboratory results were abstracted. Student t test was used to test significance. A total of 79 patients were enrolled (61% male). Average age and APACHE II score were 61 ± 16 years and 18 ± 9, respectively. Factor-associated coagulation measures and MA were normal in all groups but MA-AA and MA-ADP were significantly reduced irrespective of anticoagulant use. Compared to the nonanticoagulated cohort, MA-AA was significantly reduced in those on aspirin. There was no difference in mortality or length of stay in any cohort. Inhibition of the AA and ADP pathways is common in critically ill patients. Clinical correlation with propensity for bleeding and need for transfusion requires further assessment.

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.

The Impact of Nutritional Status and Complete Blood Count Parameters on Clinical Outcome in Geriatric Critically Ill Patients

Background

The geriatric population in intensive care units (ICUs) has recently increased. The aim of this study was to analyse the impact of initial complete blood count (CBC)-related parameters and nutritional status on morbidity and mortality in geriatric ICU patients.

Methods

A retrospective analysis was made of geriatric patients admitted to our tertiary adult ICU for 1 year. Patients with a length of stay (LOS) of < 48 h, with hematological malignancy or age < 65 years age were excluded from the study. Initial albumin level was considered to reflect nutritional status. The prevelance and risk factors of mortality and microbiologically documented infection (MDI) were analysed.

Results

The study included a total of 243 patients with a mean age of 78.96 ± 6.62 years. The overall mortality rate was 40.7%. The most common cause for admission was acute respiratory failure and sepsis (17.2% vs. 16.8%). The most common MDI sources were lower respiratory tract, bloodstream, and urinary tract infections. Patients with thrombocytopenia on admission had a higher mortality rate than patients with normal platelet count (P = 0.019). The initial albumin level of non-survivors was significantly lower than that of survivors (P = 0.001). There was a significant negative correlation between albumin level and LOS (r = -0.157; P = 0.000). Patients with hypoalbuminemia (albumin < 3.2 g/dL) at the time of diagnosis had higher mortality, LOS and MDI rates than those with normal albumin levels (P < 0.05). There was no significant relationship between any other CBC-related parameter and infection and mortality (P > 0.05).

Conclusions

Thrombocytopenia and hypoalbuminemia may be considered as major risk factors for morbidity and mortality in critically ill elderly patients.

Is the mean platelet volume a predictive marker of a high in-hospital mortality of acute cardiorenal syndrome patients receiving continuous renal replacement therapy?

A high mean platelet volume (MPV) level has been demonstrated to predict poor clinical outcomes in patients with cardiovascular disease. However, the relationship between MPV and mortality in patients with acute cardiorenal syndrome (ACRS) is unknown. Therefore, we investigated the predictive value of MPV for in-hospital mortality of patients with ACRS who received continuous renal replacement therapy (CRRT) in this study.We retrospectively analyzed the demographics, etiology, severity of illness, prognosis, and risk factors of ACRS patients who underwent CRRT in our hospital from January 2009 to December 2014. Patients were classified into 2 groups based on the prognosis and timing of CRRT. The receiver operating characteristic curve was used to examine the performance of MPV in predicting in-hospital mortality. Baseline characteristics, clinical, and hematological parameters at CRRT initiation were compared between the 2 groups. Factors influencing in-hospital mortality were analyzed by univariate logistic regression analysis.The median age of patients was 74 years. Acute myocardial infarction was the most common cause of ACRS, followed by acute decompensated heart failure. The in-hospital mortality was 51.4%. Age, number of organ failure, APACHE II score, and MPV in the nonsurvivors were significantly higher than those in the survivors (P < .05). However, the cardiac function and mean arterial pressure were significantly lower in the nonsurvivors (P < .05). The prognosis of the early intervention group was better than the late-intervention group, but no significant difference was found (P > .05). The area under the curve (AUC) for in hospital mortality based on MPV was 0.735. Univariate analysis showed that age, cardiac function NYHA class, number of organ failure, APACHE II score, MAP, MPV, and use of vasopressors were associated with the prognosis of patients (P < .05).These findings suggest that the prognosis of patients with ACRS who received CRRT was poor, and MPV might be useful as a marker for predicting the in-hospital mortality of these patients.

Association of Preoperative Cell Counts With Outcomes After Operation for Congenital Heart Disease

BACKGROUND

We examined the association of preoperative cell count abnormalities, which have been shown to be associated with outcomes in adult cardiac patients, with morbidity and mortality after operation for congenital heart disease (CHD) in children.

METHODS

We performed a retrospective cohort study on 4,865 children undergoing cardiac operation from 2004 to 2014. Our exposures of interest were presence of preoperative lymphopenia (lymphocyte count ≤ 3,000 cells/μL), thrombocytopenia (platelet count < 150 × 10³/μL), and neutrophilia (neutrophil count ≥ 7,000 cells/μL). Our outcomes of interest were mortality status, postoperative length of stay (LOS), and occurrence of postoperative complications. We performed logistic and linear regressions to determine the associations of preoperative cell counts with mortality, LOS, and complications, adjusting for age, sex, race or ethnicity, presence of a genetic syndrome, and Society of Thoracic Surgeons and European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality category.

RESULTS

Overall mortality was 2.8%, median LOS was 6 days, and 7.6% of patients had postoperative complications. Lymphopenia was associated with increased odds of postoperative mortality (odds ratio 1.67, 95% confidence interval: 1.15 to 2.43, p = 0.007). Lymphopenia, thrombocytopenia, and neutrophilia were all associated with longer postoperative LOS. Lymphopenia and thrombocytopenia were associated with increased occurrence of postoperative sepsis, and neutrophilia was associated with need for postoperative mechanical circulatory support.

CONCLUSIONS

In children undergoing CHD operation, preoperative lymphopenia is associated with increased in-hospital mortality postoperatively. Preoperative lymphopenia, neutrophilia, and thrombocytopenia are associated with longer postoperative LOS and with development of postoperative complications. Preoperative cell counts may serve as important prognostic markers in preoperative planning for patients with CHD.

High-Density Lipoprotein, Mean Platelet Volume, and Uric Acid as Biomarkers for Outcomes in Patients With Sepsis: An Observational Study

BACKGROUND

We conducted an observational study evaluating the association between uric acid, mean platelet volume (MPV), and high-density lipoprotein (HDL) with complications and outcomes of patients with sepsis in a critical care setting.

METHODS

We followed patients with a diagnosis of severe sepsis and septic shock for a maximum of 28 days. Main outcomes assessed included length of stay (LOS), the need for renal replacement therapy (RRT), assisted mechanical ventilation (AMV), and vasopressor support as well as in-unit mortality.

RESULTS

The overall average age of the 37 patients enrolled was 48.1 (19.8) years; among them, 37.8% were male. Abdominal related (43.2%) and pulmonary (29.7%) were the main sites of infection. The overall Acute Physiology and Chronic Health Evaluation 2 (APACHE-2) median score was 19 (9-24). Acute kidney injury (AKI) was observed in 46.9% of the sample. In all, 54.1% required vasopressor support, 54.1% AMV, and 35.1% RRT. Patients with bacteremia were significantly more likely to require vasopressor support and those with urinary tract infections were significantly younger. We found increasing ΔMPV levels, higher APACHE-2 scores, lower HDL values, and a reduced age to be associated with a longer LOS. Higher scores on the APACHE-2 scale and lower levels of HDL significantly associated with higher odds for developing AKI. The need for vasopressor support was significantly associated with higher values of 72-hour MPV and with higher levels of baseline uric acid and lower values of initial HCO₃. Initial and 72-hour levels of MPV and higher scores in the APACHE-2 were all significantly correlated with the need for AMV. An increased probability of dying during follow-up was significantly correlated with increasing age.

CONCLUSION

We were able to establish significant associations between our candidate biomarkers and relevant outcomes for patients with sepsis. Our results support the use of these low-cost biomarkers in the assessment of prognosis of patients with sepsis.

Combination of Mean Platelet Volume/Platelet Count Ratio and the APACHE II Score Better Predicts the Short-Term Outcome in Patients with Acute Kidney Injury Receiving Continuous Renal Replacement Therapy

BACKGROUND/AIMS

Both the Acute physiology and Chronic Health Evaluation (APACHE II) score and mean platelet volume/platelet count Ratio (MPR) can independently predict adverse outcomes in critically ill patients. This study was aimed to investigate whether the combination of them could have a better performance in predicting prognosis of patients with acute kidney injury (AKI) who received continuous renal replacement therapy (CRRT).

METHODS

Two hundred twenty-three patients with AKI who underwent CRRT between January 2009 and December 2014 in a Chinese university hospital were enrolled. They were divided into survivals group and non-survivals group based on the situation at discharge. Receiver Operating Characteristic (ROC) curve was used for MPR and APACHE II score, and to determine the optimal cut-off value of MPR for in-hospital mortality. Factors associated with mortality were identified by univariate and multivariate logistic regression analysis.

RESULTS

The mean age of the patients was 61.4 years, and the overall in-hospital mortality was 48.4%. Acute cardiorenal syndrome (ACRS) was the most common cause of AKI. The optimal cut-off value of MPR for mortality was 0.099 with an area under the ROC curve (AUC) of 0.636. The AUC increased to 0.851 with the addition of the APACHE II score. The mortality of patients with of MPR > 0.099 was 56.4%, which was significantly higher than that of the control group with of ≤ 0.099 (39.6%, P= 0.012). Logistic regression analysis showed that average number of organ failure (OR = 2.372), APACHE II score (OR = 1.187), age (OR = 1.028) and vasopressors administration (OR = 38.130) were significantly associated with poor prognosis.

CONCLUSION

Severity of illness was significantly associated with prognosis of patients with AKI. The combination of MPR and APACHE II score may be helpful in predicting the short-term outcome of AKI.

How I treat disseminated intravascular coagulation

Disseminated intravascular coagulation (DIC) is a condition characterized by systemic activation of coagulation, potentially leading to thrombotic obstruction of small and midsize vessels, thereby contributing to organ dysfunction. At the same time, ongoing consumption of platelets and coagulation proteins results in thrombocytopenia and low concentrations of clotting factors, which may cause profuse hemorrhagic complications. DIC is always secondary to an underlying condition, such as severe infections, solid or hematologic malignancies, trauma, or obstetric calamities. A reliable diagnosis of DIC can be made through simple scoring algorithms based on readily available routine hemostatic parameters. The cornerstone of supportive treatment of this coagulopathy is management of the underlying condition. Additionally, administration of heparin may be useful, and restoration of physiological anticoagulants has been suggested, but has not been proven successful in improving clinically relevant outcomes so far. In patients with major bleeding or at risk for hemorrhagic complications, administration of platelet concentrates, plasma, or coagulation factor concentrates should be considered.