Changes in mean platelet volume in critically ill children and its relation to other clinical and laboratory findings. Abeer Abd Elmoneim 1,2* , Abdel Rahman Alhojaili 3 , Noha Reda Banjer 3 , Mohammed Zolaly 1 , Ehab Saoud Abd El-Moneim 1,2 1 Pediatric Department, Taibah University, Almadinah Almounourah, Saudi Arabia 2 Pediatric Department, Sohag University, Sohag, Egypt 3 Pediatric Intensive Care Unit (PICU), Maternity and Child Health (MCH) Hospital Almadinah Almounourah, Saudi Arabia Abstract Background: Mean Platelet Volume (MPV) is a measure of platelet size, and is influenced by inflammation which is commonly overlooked by clinicians. In critically ill patients, sepsis is a major problem and considered a generalized process that involves all body organs and systems. Hemostatic system is commonly involved in any sepsis condition. The aim of this study is to detect changes of MPV on admission in critically ill children and determine its relation to other clinical and laboratory parameters that can be indicators of sepsis. Materials and methods: Critically ill children, aged between 1 month and 12 y, consecutively presented to Pediatric Intensive Care Unit (PICU) were assessed for possible enrolment in the study. Venous blood samples were collected from all included children at initial presentation, at 12 h and 48 h after PICU admission. MPV and other blood indices were measured and compared with systemic inflammatory process serum markers. Results: Changes in platelets count did not show any significant differences during the first 48 h in both MPV-rise (p=0.22) and MPV-no/rise groups (p=0.09). Changes in Procalcitonin (PCT) were significant in MPV-rise (p˂0.001) but not in MPV-no/rise groups (p=0.06). Conclusions: The results of this study demonstrate a strong relation between the increase in MPV from baseline in critically ill children admitted to PICU with important laboratory and clinical variables. Keywords: Platelet volume, Critically ill children, Sepsis. Accepted on January 17, 2018 Introduction Mean Platelet Volume (MPV) is a simple measure of platelet size that can detect abnormal function and activity of platelets [1]. Increased MPV means more platelet activity and excessive secretion of mediators [2]. It gives an indication about the extent of inflammatory process and activity of disorders like preeclampsia, angina and myocardial infarction and systemic inflammatory conditions, such as ulcerative colitis [3,4]. Critically ill patients usually have changes in platelet function and counts that have been studied in previous studies [5-8], where a serious pathophysiologic reaction manifested by decrease in platelet number and function results from the interaction between platelets with pathogen and endothelial cells [6,7,9,10]. Increased MPV in the first 72 h of hospital admission with a marked rise in MPV in non-survivors than in survivors is found in septic inflammatory conditions in adults. Besides, the change in MPV after 72 h is found to be an independent risk factor of mortality [11]. In critical care settings, patients with systemic infection that associated with organ dysfunction or shock are usually can’t be distinguish from those with similar clinical signs but without infection. Traditional inflammatory markers (leukocytes, C- reactive protein) can be influenced by parameters other than infection and are slowly released. Contamination usually affects positive bacterial cultural results and negative results do not mean to roll out sepsis [12]. Other laboratory tests are required to give an early indication of infection in inflammatory cases. These tests will replace traditional inflammatory markers that do not have the needed sensitivity and specificity. Procalcitonin (PCT) serum level is one of these needed tests to mark the inflammatory response to infection [5,6,13-15]. Normally, all PCT is transformed to calcitonin inside the thyroid gland after its production. Therefore PCT level in the serum is undetectable (<0.1 ng/ml) in healthy humans. During severe infections serum PCT levels may increase to over 100 ng/ml. The pathophysiological role of serum PCT during sepsis is not clear [7,14]. During sever ISSN 0970-938X www.biomedres.info Biomedical Research 2018; 29 (5): 882-888 Biomed Res 2018 Volume 29 Issue 5 882