An increase in mean platelet volume after admission is associated with higher mortality in critically ill patients.

Fernando G Zampieri,Otavio T Ranzani,Heraldo Possolo De Souza,Fabiano Pinheiro Da Silva,Viviane Sabatoski,Luiz Monteiro Cruz Da Neto,Hermes Barbeiro,Marcelo Park

doi:10.1186/s13613-014-0020-1

Abstract

BackgroundPlatelet activation and consumption are common in critically ill patients and are associated with poorer prognosis. Mean platelet volume is a simple surrogate for platelet activation, with higher MPV being associated with worse clinical condition on a large array of clinical diagnoses. We therefore aimed to investigate associations between changes in platelet count and mean platelet volume (MPV) with prognosis and inflammatory cytokine values in critically ill patients.MethodsThis study prospectively included 84 critically ill patients. Patients were stratified into four groups according to proportional changes in MPV (ΔMPV24h) and platelet count (ΔPlat24h) in the first 24 hours after admission. Mortality between groups was compared using the χ2 test. Logistic regression was performed using hospital mortality as outcome and Simplified Acute Physiology Score (SAPS 3), ΔPlat24h and ΔMPV24h as covariates. Concentrations of the following inflammatory mediators were measured using Miliplex® technology: IL1β, IL6, IL8, IL10, epidermal growth factor, vascular endothelial growth factor, TNFα and IFNα. Cytokine concentrations were compared between groups using the Kruskal-Wallis test with Bonferroni correction.ResultsPatients in whom MPV increased and platelet count decreased had higher mortality rates (46%). According to logistic regression, ΔMPV24h was independently associated with increased mortality (OR 1.28 per 1% increase; 95% CI 1.08 to 1.48). No strong associations between inflammatory mediators and changes in MPV and platelet count were found.ConclusionAn increase in MPV after admission to an ICU is independently associated with higher hospital mortality.

Highlights

Platelet activation and consumption are common in critically ill patients and are associated with poorer prognosis
During the study time window, renal replacement therapy (RRT) was required in 24 patients; continuous hemofiltration with citrate region anticoagulation was the initial method used in all hemodynamic unstable patients; of those, six were converted to the intermittent method after hemodynamic stabilization
According to logistic regression analysis, only higher ΔMPV24h values and Simplified Acute Physiology Score (SAPS) 3 scores were associated with increased mortality; changes in platelet count in the first 24 hours had no impact on short-term prognosis

Summary

Introduction

Platelet activation and consumption are common in critically ill patients and are associated with poorer prognosis. We aimed to investigate associations between changes in platelet count and mean platelet volume (MPV) with prognosis and inflammatory cytokine values in critically ill patients. It is not surprising that absolute platelet count and Inflammatory and thrombotic conditions may alter platelet size, which can be detected on routine blood cell analysis by evaluation of mean platelet volume (MPV) [6,7,8]. In several inflammatory clinical conditions, the degree of inflammation and changes in MPV appear to be correlated; the impact of this is controversial [6,7,8]. Because there is a strong inverse correlation between platelet count and MPV in healthy individuals, trends in platelet count should be considered when evaluating MPV [8]

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