Utility of Platelet Indices in Critically ill Children

Research Article

Austin J Clin Med. 2024; 9(1): 1045.

Utility of Platelet Indices in Critically ill Children

Nagwan Y Saleh*; Ahmed A Khatab; Muhammad S El-Mekkawy; Shaimaa M Nomair

Department of Pediatrics, Faculty of Medicine, Menoufia University, Shebin Elkom, Egypt

*Corresponding author: Nagwan Yossery Saleh Corresponding author. Professor of Pediatrics, Faculty of Medicine, Menoufia University Hospital, Yassin Abdel-Ghafar Street, Shebin El-kom, Menoufia, 32511, Egypt. Tel: + 201060408035 Email: [email protected]

Received: March 04, 2024 Accepted: April 09, 2024 Published: April 16, 2024

Abstract

Background: Platelet indices have been recently used to predict outcomes for critically ill patients but Pediatric data is limited. We aimed to evaluate role of platelet indices in diagnosis of sepsis and predicting prognosis among critically ill children.

Methods: This was prospective observational study conducted on 133 children admitted to Pediatric Intensive Care Unit (PICU) of a tertiary center. Patients were evaluated on admission by routine laboratory biomarkers and clinical risk score, in addition to platelet indices, namely Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), and Plateletcrit (PCT). Patients were followed up till hospital discharge. Primary outcome was PICU mortality.

Results: 133 patients were recruited.47.4% had sepsis; 7.5% had non-infectious Systemic Inflammatory Response Syndrome (SIRS); and 45.1% had no SIRS. No Significant difference in all platelet indices was observed between sepsis, non- infectious SIRS, and non-SIRS. MPV was significantly higher among non-survivors compared with survivors [median and IQR: 8.2(7.7–9.9)] but no significant difference was found between the two groups in PCT and PDW. Serum albumin, platelet count, and WBC were significantly lower among non-survivors.Multivariate logistic regression analysis revealed that mechanical ventilation and serum albumin are independent predictors of mortality [ORand 95% CI: 37.1(4.4–311.7) and 0.26(0.09–0.72) respectively]. MPV and PDW were positively correlated, while PCT were negatively correlated, with pSOFA score [Rs: 0.21, 0.17, -0.22; p=0.017, 0.048, 0.009].

Conclusion: Platelet indices have no value for diagnosis of sepsis but they possess some prognostic value. However, mechanical ventilation and serum albumin are independent far superior as prognostic indicators.

Keywords: Mean platelet volume; Mortality; Pediatric; Plateletcrit; Platelet distribution width

Introduction

Critical illness is made up of a heterogeneous group of disorders that share a risk of organ dysfunction, long-term morbidity, and mortality [1]. Approximately 80% of the patients admitted into Intensive Care Units (ICU) survive the acute event, and most remain in this unit briefly. However, a subgroup does not recover sufficiently quickly to become independent and from then they recover slowly, these patients are called Chronically Critically Ill (CCI) patients who comprise 5 to 10% of the patients admitted into Intensive Care Units [2].

The outcome of critically ill children recovering from life threatening diseases in intensive care situations has improved owing to advancing diagnostic and therapeutic methods. Clinicians recognized the importance of identifying patients with the highest risk of mortality among those admitted to the PICU, and of proper monitoring and appropriate intervention and treatment [3].

Pediatric critical illness can profoundly disrupt child health and development and negatively affect family function and well-being. Although (PICU) mortality is declining, a growing number of survivors develop deficits that persist beyond hospital discharge [4].

Platelet (PLT), a major and essential constituent of blood, plays an important role in physiological and pathological processes such as coagulation, thrombosis, inflammation and maintenance the integrity of vascular endothelial cells, by mediate leukocyte movement from the bloodstream through the vessel wall to tissue; platelets also secrete microbicidal proteins and antibacterial peptides [5].

Platelet indices are biomarkers of platelet activation. They allow extensive clinical investigations focusing on the diagnostic and prognostic values in a variety of settings without bringing extra costs. Among these platelet indices Plateletcrit (PCT), Mean Platelet Volume (MPV) and Platelet Distribution Width (PDW) are a group of platelet parameters determined together in automatic Complete Blood Count (CBC) profiles, they are related to platelet’s morphology and proliferation kinetics [6].

When platelet production is decreased, young platelets become bigger and more active, and MPV levels increase. Increased MPV indicates increased platelet diameter, which can be used as a marker of production rate and platelet activation [7].

PDW is numerically equal to the coefficient of PLT volume variation, which is used to describe the dispersion of PLTs volume [8]. Platelets play an important role in inflammation, and recently, several additional functions for platelets in the process of inflammation were defined [9]. The objective of the present study was to assess the role of platelet indices in diagnosis and prognosis of critically ill children in Pediatric Intensive Care Unit

Subjects and Methods

The Design of the Study

In this prospective study, we enrolled 133 critically ill children admitted to a 10-bed PICU at Menoufia University Hospital, Egypt, from March 2019 to September 2020. The Scientific and Ethical Committee approved the study protocol of Menoufia University, and informed consent was obtained from parents before enrolling their children in the study. Critically ill children in the PICU aged 1 month to 18 years were included in this study. Exclusion criteria were 1) age less than one month or more than 18 years and 2) Any children with aplastic anemia or received immunosuppression drugs or platelets disorders and oncology patients with bone marrow depression and 3) inability to follow up for the first 30 days after discharge.

The PICU Patients

The included patients were diagnosed according to the International Pediatric Sepsis Consensus Conference, characterizing, sepsis, non-infectious SIRS, and non-SIRS [10]. Sepsis is a systemic response to an infectious stimulus characterized by two or more of the following, resulting in infection: (a) a temperature of more than 38°C or less than 36°C, (b) pulse rate > 90 beats/minute, (c) breath rate > 20 breaths /minute or PaCO2 < 32 mm Hg, and (d) White Blood Cell count (WBC) of > 12000/mm3 or < 4000/mm3, or > 10% immature (band) formation in a total blood count.

The Outcomes of the Study

The primary outcome measure was PICU mortality during hospital admission or during the 30-days follow up period after hospital discharge. The length of stay (PICU and hospital), need and duration of Mechanical Ventilation (MV) were secondary outcomes.

The Method of the Study

We collected the complete history of all children including in this study, including age, sex, admission data, and length of stay in the PICU and the inpatient department. Vital signs, anthropometric measurements, and examination of all body systems were also assessed. PICU scoring systems were applied, including the 1) Pediatric Risk of Mortality score (PRISM) 2) Pediatric Index of Mortality-2 (PIM2), and 3) Pediatric Sequential Organ Failure Assessment Scale (pSOFA). The PRISM score was calculated within 24 hours of admission for each patient, using 14 clinical and laboratory variables. Values for these variables were entered into the PRISM application (http://www.sfar.org/scores2/prism2.php), which calculates the expected death rate [11]. PIM2 is a more rapid technique for which scores are estimated within 1 hour of in-person contact with the patient, and scores correspond to a predicted mortality rate [12]. The pediatric Sequential Organ Failure Assessment Scale (pSOFA) is used to assess organ dysfunction. Depending on the patient's baseline risk level, a pSOFA score of 2 or greater corresponds to a 2- to 25-fold greater risk of death than patients with pSOFA scores was less than 2 [13].

Arterial blood gases, random blood glucose, and Complete Blood Count (CBC) were analyzed (Pentra ABX 80 analyzer; Horiba, Paris, France). C-Reactive Protein (CRP), hepatic function (alanine aminotransferase and aspartate aminotransferase) was determined using a kinetic UV-optimized IFCC method (LTEC Kit, England). Renal function (blood urea and serum creatinine) was determined colorimetrically (Diamond Diagnostic kit, Germany). Blood culture, chest X- radiography, brain CT, and other laboratory or radiological analyses were performed as needed.

The procedure: Platelet Distribution Width (PDW): is a regular parameter in blood routine examination which reflects variation of platelet size distribution with a range from 8.3% to 56.6%. Mean Platelet Volume (MPV): MPV was calculated by the following formula: MPV (fL) = [(PCT (%)/platelet count (×10 /l)] × 105. Plateletcrit (PCT): is the volume occupied by platelets in the blood as a percentage and calculated according to the formula PCT = platelet count × MPV / 10,000 (within 24 hours of PICU admission).

Statistical Analysis

Data were statistically analyzed using SPSS (version 19, SPSS Inc, Chicago, Illinois). Descriptive statistics included arithmetic medians and Interquartile Ranges (IQRs) of quantitative data and numbers and percentages of qualitative data. Analytical statistics included the Chi-square (Χ2) test, Student's t-test, Mann-Whitney test, and Fisher's exact test. We used logistic regression models to determine the ability of platelets indices to predict mortality. Receiver operating characteristics (ROC) analysis was performed for the diagnostic and prognostic powers of the platelet’s indices, and other variables. P-values < 0.05 were considered significant.

Results

Table 1 showed demographic and clinical data of survivors and non-survivors. Non-survivors had significantly higher frequency of severe sepsis, Acute Respiratory Distress Syndrome (ARDS), mechanical ventilation, Multiple Organ Dysfunction Syndrome (MODS) and nosocomial infections. Non survivors also had significantly higher pSOFA score, PRISM, and longer duration of mechanical ventilation.