The role of C-reactive protein as a risk marker of postoperative delirium in older hip fracture patients: a prospective cohort study

PURPOSE

Postoperative delirium (POD) is a common and serious neuropsychiatric syndrome that leads to higher morbidity and mortality. We investigated the association between serum C-reactive protein (CRP) and the occurrence of POD in older hip fracture patients, and whether CRP predicted POD better than a clinical model.

METHODS

Patients aged ≥ 75 years admitted for surgical repair of an acute hip fracture were recruited. We compared serum CRP levels between patients with and without POD.

RESULTS

Sixty patients were included, of whom 21 (35%) developed POD. Serum CRP levels were significantly higher in patients who developed delirium (p = 0.011). In a multiple regression model including clinical variables and CRP, cognitive impairment (p = 0.003) and infection (p = 0.001) were the best predictors of POD.

CONCLUSIONS

Although higher levels of serum CRP were significantly associated with POD in older hip fracture patients, pre-existing cognitive impairment and infections were the most important risk factors for POD.

Presepsin in Critical Illness: Current Knowledge and Future Perspectives

The accurate identification of infections is critical for effective treatment in intensive care units (ICUs), yet current diagnostic methods face limitations in sensitivity and specificity, alongside cost and accessibility issues. Consequently, there is a pressing need for a marker that is economically feasible, rapid, and reliable. Presepsin (PSP), also known as soluble CD14 subtype (sCD14-ST), has emerged as a promising biomarker for early sepsis diagnosis. PSP, derived from soluble CD14, reflects the activation of monocytes/macrophages in response to bacterial infections. It has shown potential as a marker of cellular immune response activation against pathogens, with plasma concentrations increasing during bacterial infections and decreasing post-antibiotic treatment. Unlike traditional markers such as procalcitonin (PCT) and C-reactive protein (CRP), PSP specifically indicates monocyte/macrophage activation. Limited studies in critical illness have explored PSP's role in sepsis, and its diagnostic accuracy varies with threshold values, impacting sensitivity and specificity. Recent meta-analyses suggest PSP's diagnostic potential for sepsis, yet its standalone effectiveness in ICU infection management remains uncertain. This review provides a comprehensive overview of PSP's utility in ICU settings, including its diagnostic accuracy, prognostic value, therapeutic implications, challenges, and future directions.

Presepsin in the diagnosis of sepsis

OBJECTIVES

Sepsis is a life-threatening condition characterized by organ dysfunction. It occurs due to the host's dysregulated response to an infection. Clinicians use inflammatory biomarkers to evaluate patients at risk of sepsis in various settings.

METHODS

We included studies focusing on the diagnostic accuracy of presepsin in patients under suspicion of sepsis. The bivariate model of Reitsma was used for the quantitative synthesis, and summary estimates were calculated. The Zhou-Dendukuri approach was followed to assess heterogeneity. Subgroup analyses were performed based on settings and diagnostic criteria.

RESULTS

The summary sensitivity for diagnosing sepsis was 0.805 (95 % CI: 0.759-0.844), while the false positive rate (FPR) was 0.174 (95 % CI: 0.124-0.239). The area under the curve (AUC) for the summary receiver operating characteristic (SROC) curve was 0.875, with a slightly lower partial AUC of 0.833. The analysis using the Zhou-Dendukuri approach revealed low heterogeneity (I2 = 15.9 %). Subgroup analyses showed no significant differences in SROC curves and summary estimates between the ED and ICU settings, although the ED subgroup exhibited higher heterogeneity (I2 = 52.7 % vs. 20.2 %). The comparison between the diagnostic criteria, Sepsis 1 and Sepsis 3, demonstrated similar summary estimates and SROC curves. The examination of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool revealed a high risk of bias regarding the participants and their applicability. Also, there was an increased risk of bias in all the studies concerning the index test.

CONCLUSION

Based on our research, presepsin is a promising biomarker for triage and early diagnosis of sepsis.

Biomarkers in sepsis-looking for the Holy Grail or chasing a mirage!

Sepsis is defined as a life-threatening organ dysfunction caused by the dysregulated host response to infection. It is a complex syndrome and is characterized by physiologic, pathologic and biochemical abnormalities in response to an infection. Diagnosis of sepsis is based on history, physical examination and other investigations (including biomarkers) which may help to increase the certainty of diagnosis. Biomarkers have been evaluated in the past for many diseases and have been evaluated for sepsis as well. Biomarkers may find a possible role in diagnosis, prognostication, therapeutic monitoring and anti-microbial stewardship in sepsis. Since the pathophysiology of sepsis is quite complex and is incompletely understood, a single biomarker that may be robust enough to provide all information has not been found as of yet. However, many biomarkers have been studied and some of them have applications at the bedside and guide clinical decision-making. We evaluated the PubMed database to search for sepsis biomarkers for diagnosis, prognosis and possible role in antibiotic escalation and de-escalation. Clinical trials, meta-analyses, systematic reviews and randomized controlled trials were included. Commonly studied biomarkers such as procalcitonin, Soluble urokinase-type plasminogen activator (Supar), presepsin, soluble triggering receptor expressed on myeloid cells 1, interleukin 6, C-reactive protein, etc., have been described for their possible applications as biomarkers in septic patients. The sepsis biomarkers are still an area of active research with newer evidence adding to the knowledge base continuously. For patients presenting with sepsis, early diagnosis and prompt resuscitation and early administration of anti-microbials (preferably within 1 h) and source control are desired goals. Biomarkers may help us in the diagnosis, prognosis and therapeutic monitoring of septic patients. The marker redefining our view on sepsis is yet a mirage that clinicians and researchers continue to chase.