Platelet Function and Morphology in Patients with Sepsis and Septic Shock: A Retrospective Pilot Study

Background: Sepsis remains a leading cause of mortality in the intensive care unit (ICU). Platelets (PLTs) are central to coagulation, inflammation, and the maintenance of endothelial integrity. Although thrombocytopenia is an established prognostic marker in sepsis, alterations in PLT function and morphology may provide additional insight into disease progression. Methods: This retrospective pilot study examined adult ICU patients diagnosed with sepsis or septic shock. Extracted data included demographic characteristics, clinical variables, and laboratory parameters. Platelet function was evaluated using impedance aggregometry and rotational thromboelastometry (ROTEM), while PLT morphology metrics were obtained from complete blood counts. Statistical analyses comprised Spearman’s rank correlation and logistic regression. Results: Twenty patients were included. Platelet aggregation was impaired across ASPI, ADP, and TRAP-6 assays despite normal PLT counts and morphology. ROTEM-derived measure of PLT contribution to clot strength was within normal ranges. No correlations were observed between PLT function and PLT morphology parameters. An inverse correlation was identified between ROTEM-derived PLT contribution to clot strength and SOFA score (r = −0.60, p = 0.03). Neither PLT function nor PLT morphology was associated with ICU mortality. Conclusions: Functional PLT deficits may occur in sepsis in the absence of structural abnormalities. ROTEM-derived PLT contribution to clot strength may inversely reflect sepsis severity. Platelet function parameters appear unlikely to predict short-term mortality in septic patients.