Role of C-reactive protein velocity in the diagnosis of early bacterial infections in children after cardiac surgery

Estimated C-reactive protein (CRP) velocity for rapidly distinguishing bacterial from other etiologies in children presenting to emergency department with remarkably elevated CRP levels

The use of a single C-reactive protein (CRP) value to differentiate between bacterial and non-bacterial causes is limited. Estimated CRP velocity (eCRPv) has shown promise in enhancing such discrimination in adults. This study aims to investigate the association between eCRPv and bacterial etiologies among pediatric patients with very elevated CRP levels. We conducted a retrospective analysis of patients under 18 years of age who had been admitted to our Pediatric Emergency Department from 2018 to 2020 with a fever and CRP levels ≥ 150 mg/L. Bacterial and non-bacterial etiologies were determined from hospital discharge diagnoses, which were monitored independently by three physicians from the research team. The records of 495 suitable patients (51.2% males, median age 3.2 years) were retrieved of whom 444 (89.7%) were eventually diagnosed with bacterial infections. The mean CRP levels were significantly higher for bacterial etiologies compared with other causes (209.2 ± 59.8 mg/L vs. 185.6 ± 35.8 mg/L, respectively, p < .001), while the mean eCRPv values did not differ significantly (p = .15). In a time course analysis, we found that specifically in patients presenting ≥ 72 h after symptom onset, only a eCRPv1 level > 1.08 mg/L/h was an independent predictor of bacterial infection (aOR = 5.5 [95% CI 1.7-17.8], p = .004).   Conclusion: Pediatric patients with very high CRP levels and fever mostly have bacterial infections. eCRPv levels, unlike CRP values alone, can serve as the sole independent predictor of bacterial infection > 72 h from symptom onset, warranting further prospective investigations into CRP kinetics in pediatric patients. What is Known: • The use of a single C-reactive protein (CRP) value to differentiate between bacterial and non-bacterial causes is limited. • Estimated CRP velocity (eCRPv) has shown promise in enhancing such discrimination in adults, but data on CRP kinetics in pediatric patients is sparse. What is New: • eCRPv levels, unlike CRP values alone, can serve as the sole independent predictor of bacterial infection > 72 h from symptom onset in pediatric patients with remarkably elevated CRP levels.

Early signaling of bacteremia in patients who present to the Department of Emergency Medicine with relatively low C-Reactive Protein (CRP) concentrations

OBJECTIVES

Examiningthe usefulness of C-reactive protein velocity (CRPv) as an early biomarker for the presence of bacteraemia in patients presenting to the Department of Emergency Medicine with acute infection/inflammation and suspected bacteraemia.

METHODS

A retrospective study examining a cohort of patients who presented to the E.R and in whom blood cultures were taken. CRPv was calculated as the difference in mg/hour/litter between two consecutive CRP tests performed within 12 hours.

RESULTS

256 patients were included in the cohort. Using CRPv in patients who at first presented with a relatively low (17.9≤mg/L 1^stquartile) CRP concentration, we found an AUC of 0.808±0.038 (p<0.001) for the presence of positive versus negative blood cultures (what is AUC?). This was better than the AUC that was obtained when the WBC for the same purpose.

CONCLUSIONS

CRPv may be a useful biomarker in the identification of patients with suspected bacteremiaand a low CRP-a challenging situation for clinicians who may underestimate the severity of illness in this patient group.

C-Reactive Protein Velocity (CRPv) as a New Biomarker for the Early Detection of Acute Infection/Inflammation

C-reactive protein (CRP) is considered a biomarker of infection/inflammation. It is a commonly used tool for early detection of infection in the emergency room or as a point-of-care test and especially for differentiating between bacterial and viral infections, affecting decisions of admission and initiation of antibiotic treatments. As C-reactive protein is part of a dynamic and continuous inflammatory process, a single CRP measurement, especially at low concentrations, may erroneously lead to a wrong classification of an infection as viral over bacterial and delay appropriate antibiotic treatment. In the present review, we introduce the concept of C-reactive protein dynamics, measuring the velocity of C-reactive protein elevation, as a tool to increase this biomarker’s diagnostic ability. We review the studies that helped define new metrics such as estimated C-reactive protein velocity (velocity of C-reactive protein elevation from symptoms’ onset to first C-reactive protein measurement) and the measured C-reactive protein velocity (velocity between sequential C-reactive protein measurements) and the use of these metrics in different clinical scenarios. We also discuss future research directions for this novel metric.

Procalcitonin and C-reactive protein for diagnosing post-operative sepsis in neonates

AIM

To determine whether serum procalcitonin (PCT) or C-reactive protein (CRP) can diagnose post-operative sepsis among neonates undergoing major non-cardiac surgery.

METHODS

In this diagnostic study, we included neonates who underwent major non-cardiac surgery and were monitored for post-operative sepsis. We excluded pre-existing septic, inflammatory or life-threatening conditions. Subjects either had 'definite' (culture-positive, n = 14), 'probable' (clinical sepsis, culture-negative, n = 25) or no sepsis (n = 31). We measured serum CRP and PCT at 48 ± 6 h, 72 ± 6 h and 96 ± 6 h post-operatively and compared 'definite or probable sepsis' with 'no sepsis'.

RESULTS

Median (Q1, Q3) CRP (mg/L) in 'definite or probable' sepsis group was higher than 'no sepsis' at 72 h (91.48 (57.87, 143.50) vs. 51.32 (33.0, 80.1); P = 0.009) and 96 h (87.51 (45.19, 128.22) vs. 31.00 (25.3, 45.2); P < 0.001). Median (Q1, Q3) PCT (ng/mL) in 'definite or probable' sepsis was higher than 'no sepsis' at 72 h (4.22 (2.04, 12.73) vs. 1.78 (0.9, 6.4); P = 0.01) and 96 h (3.54 (1.96, 9.65) vs. 0.97 (0.4, 3.0); P < 0.001). Ninety-six-hour CRP and PCT cut-offs (based on Youden's index) were 74.16 mg/L and 1.65 ng/mL, respectively. If both CRP and PCT were positive, specificity was 100% (95% confidence interval: 88.78-100). If either one was positive, sensitivity was 88.89% (95% confidence interval: 73.94-96.89).

CONCLUSIONS

Septic neonates have significantly higher serum CRP and PCT compared to non-septic neonates at 72 and 96 h post-operatively. If both CRP and PCT are positive at 96 h after surgery, it has 100% specificity, and if either one is positive, 89% sensitivity.

C-reactive protein and procalcitonin after congenital heart surgery utilizing cardiopulmonary bypass: When should we be worried?

INTRODUCTION

To assess the efficacy of C-reactive protein (CRP) and procalcitonin (PCT) at identifying infection in children after congenital heart surgery (CHS) with cardiopulmonary bypass (CPB).

MATERIALS AND METHODS

Systematic review of the literature was conducted to identify studies with data regarding CRP and/or PCT after CHS with CPB. The primary variables identified to be characterized were CRP and PCT at different timepoints. The main inclusion criteria were children who underwent CHS with CPB. Subset analyses for those with and without documented infection were conducted in similar fashion. A p value of less than .05 was considered statistically significant.

RESULTS

A total of 21 studies were included for CRP with 1655 patients and a total of 9 studies were included for PCT with 882 patients. CRP peaked on postoperative Day 2. A significant difference was noted in those with infection only on postoperative Day 4 with a level of 53.60 mg/L in those with documented infection versus 29.68 mg/L in those without. PCT peaked on postoperative Day 2. A significant difference was noted in those with infection on postoperative Days 1, 2, and 3 with a level of 12.9 ng/ml in those with documented infection versus 5.6 ng/ml in those without.

CONCLUSIONS

Both CRP and PCT increase after CHS with CPB and peak on postoperative day 2. PCT has a greater statistically significant difference in those with documented infection when compared to CRP and a PCT of greater than 5.6 ng/ml should raise suspicion for infection.

Use of C-Reactive Protein and Ferritin Biomarkers in Daily Pediatric Practice

Recent pediatric clinical research has begun to focus on risk stratification tools using multibiomarker models. C-reactive protein (CRP) and ferriti biomarkers are widely available and used to varying degrees in daily practice, but there is no single source examining the evidence behind their use.We set out to summarize the evidence behind the use of CRP and ferritin biomarkers in pediatric practice and to begin development of a consensus for their future use for pediatricians.All the literature involving CRP and ferritin in pediatrics available on PubMed was surveyed. Research applicable to daily pediatric practice was summarized in the body of the article. Pediatric clinicians of various subspecialties contributed to the summary of the use of CRP and ferritin biomarkers in clinical practice in various disease processes. A clinical decision pathway is described, and evidence is summarized.CRP and ferritin biomarkers have diverse uses with various cutoff values in the literature, making their use in daily practice difficult. Elevation of these markers coincides with their significant elevation in uncontrolled inflammation.CRP and ferritin biomarkers are widely used in pediatrics. This review provides a resource summarizing evidence into a single source. There is sufficient evidence to indicate that these biomarkers of inflammation can be useful in guiding clinical decision making in specific clinical scenarios; however, further work is needed to improve their use in clinical practice.

Diagnosing infection after infant open heart surgery: role of procalcitonin

Background

Diagnosing infection in infants after cardiac surgery with cardiopulmonary bypass remains challenging. We aimed to determine whether procalcitonin discriminates post-cardiopulmonary bypass systemic inflammatory response syndrome from bacterial infection in infants better than C-reactive protein and leukocyte count.

Method

One hundred and eight infants underwent cardiac surgery with cardiopulmonary bypass. Leukocyte count, C-reactive protein, and procalcitonin were measured on arrival in the intensive care unit as baseline, and repeated on postoperative day 3. Bacterial infection was defined as proven infection with a positive blood or sputum culture.

Results

Twenty-four infants had proven bacterial infection. Baseline leukocyte counts and C-reactive protein levels did not differ significantly between the 2 groups. On postoperative day 3, C-reactive protein (62 vs. 38.5 mg·L−1, p = 0.01) and procalcitonin levels (6.58 vs. 0.41 ng·mL−1, p < 0.01) were higher in patients with bacterial infection. Leukocyte counts did not differ significantly between the two groups ( p = 0.94). The area under the receiver operating curve for leukocyte count, C-reactive protein, and procalcitonin was 0.49 ( p = 0.94), 0.67 ( p = 0.01), and 0.87 ( p < 0.0010), respectively. The optimal cutoff value of procalcitonin was 2.5 ng·mL−1 (sensitivity 75%, specificity 88%).

Conclusion

In infants undergoing cardiac surgery with cardiopulmonary bypass, procalcitonin discriminates bacterial infection from post-cardiopulmonary bypass systemic inflammatory response syndrome better than C-reactive protein and leukocyte count.

Immunologic and Infectious Diseases in Pediatric Cardiac Critical Care: Proceedings of the 10th International Pediatric Cardiac Intensive Care Society Conference

Since the inception of the Pediatric Cardiac Intensive Care Society (PCICS) in 2003, remarkable advances in the care of children with critical cardiac disease have been developed. Specialized surgical approaches, anesthesiology practices, and intensive care management have all contributed to improved outcomes. However, significant morbidity often results from immunologic or infectious disease in the perioperative period or during a medical intensive care unit admission. The immunologic or infectious illness may lead to fever, which requires the attention and resources of the cardiac intensivist. Frequently, cardiopulmonary bypass leads to an inflammatory state that may present hemodynamic challenges or complicate postoperative care. However, inflammation unchecked by a compensatory anti-inflammatory response may also contribute to the development of capillary leak and lead to a complicated intensive care unit course. Any patient admitted to the intensive care unit is at risk for a hospital acquired infection, and no patients are at greater risk than the child treated with mechanical circulatory support. In summary, the prevention, diagnosis, and management of immunologic and infectious diseases in the pediatric cardiac intensive care unit is of paramount importance for the clinician. This review from the tenth PCICS International Conference will summarize the current knowledge in this important aspect of our field.

Evaluation of procalcitonin, C-reactive protein, interleukin-6 & serum amyloid A as diagnostic biomarkers of bacterial infection in febrile patients

BACKGROUND & OBJECTIVES

Early identification of bacterial infection in patients with fever is important for prompt treatment. However, the available parameters such as C-reactive protein (CRP) and leukocyte counts are not very specific. This study was aimed to assess the diagnostic value of procalcitonin (PCT), CRP, interleukin-6 (IL-6) and serum amyloid A (SAA) for bacterial infection in febrile patients.

METHODS

Serum samples were collected from febrile patients between January and December 2012 and processed for blood cultures. PCT, IL-6, CRP and SAA levels were measured. The patients were divided into three groups according to the final diagnosis: bacteraemia group (group1), bacterial infection with negative blood culture (group 2) and non-bacterial infection group (group 3).

RESULTS

There were significant (P<0.05) difference in the levels of PCT, CRP, IL-6 and SAA among the three groups. The PCT levels of patients with g0 ram-positive bacterial infections were lower than g0 ram-negative bacterial infections (0.53 vs 2.13, P < 0.01). The best cut-off value to detect bacterial infections was 0.26 ng/ml for PCT. PCT, CRP, IL-6 and SAA had areas under the curve of 0.804, 0.693, 0.658 and 0.687, respectively.

INTERPRETATION & CONCLUSIONS

Our results showed PCT as a valuable marker of bacterial infections in febrile patients. PCT was superior to CRP, IL-6 or SAA in the early identification of bacterial infection. More prospective and large scale studies are warranted to confirm these findings.

Kinetics of procalcitonin and C-reactive protein and the relationship to postoperative infection in young infants undergoing cardiovascular surgery

BACKGROUND

The utility of procalcitonin (PCT) and C-reactive protein (CRP) as infectious biomarkers following infant cardiothoracic surgery is not well defined.

METHODS

We designed a prospective cohort study to evaluate PCT and CRP after infant cardiothoracic surgery. PCT and CRP were drawn preoperatively and 24/72 h postoperation or daily in delayed sternal closure patients. Presence of infection within 10 d of surgery, vasoactive-inotropic scores at 24 and 72 h, and length of intubation, intensive care unit stay, and hospital stay were documented.

RESULTS

PCT and CRP were elevated at 24 h. PCT then decreased while CRP increased in patients undergoing delayed sternal closure or cardiopulmonary bypass. In the delayed sternal closure group, PCT was significantly higher on postoperative days 2-5 in patients who ultimately developed infection. Higher PCT was independently associated with increased vasoactive-inotropic score at 72 h. CRP did not correlate with infection or postoperative support.

CONCLUSION

PCT rises after cardiothoracic surgery in infants but decreases by 72 h while CRP remains elevated. Sternal closure may affect CRP but not PCT. PCT is independently associated with circulatory support requirements at 72 h postoperation and with development of infection. PCT may have greater utility as a biomarker in this population.

Serum proteomics analysis and comparisons using iTRAQ in the progression of hepatitis B

The aim of this study was to analyze the changes in serum protein levels in the progression of hepatitis B using isobaric tags for relative and absolute quantitation (iTRAQ) analysis, in addition to comparing the serum protein levels of patients with chronic hepatitis B (CHB), patients with hepatitis B virus-induced acute-on-chronic liver failure (HBV-induced ACLF) and normal individuals. Protein analysis was performed on 15 serum samples using iTRAQ. The study population included healthy controls (n=5), patients with CHB (n=5) and patients with HBV-induced ACLF (n=5). Western blotting was used to verify the results in an additional nine serum samples from healthy controls, patients with CHB and patients with HBV-induced ACLF (n=3, respectively). Using iTRAQ analysis, 16 different serum proteins with ≥1.5-fold differences in expression levels were identified in the patients with CHB and ACLF compared with the healthy controls. Five of those proteins, C-reactive protein precursor, hemoglobin β chain variant Hb S-Wake, apolipoprotein J precursor, platelet factor 4 precursor and vitronectin, which demonstrated the greatest differences in their expression levels and the most significant correlation with liver diseases, were subsequently verified using western blotting. The western blotting results were consistent with the results from the iTRAQ. Two of the five proteins are not classified by biological process, and the biological functions of all the proteins in HBV-induced ACLF remain unclear. This preliminary study demonstrated that a correlation between the expression of various serum proteins and the different pathogenetic conditions induced by HBV may exist. The analysis of a larger number of samples is required to identify potential protein biomarkers that may be involved in the pathogenesis and progression of hepatitis B.