Procalcitonin and C-reactive protein kinetics in postoperative pediatric cardiac surgical patients

Low monocytic HLA-DR expression in critically ill patients of sepsis: An indicator for antimicrobial and/or immunomodulatory intervention

BACKGROUND

Sepsis is a result of suppressed host immune response which leads to fatal multi-organ dysfunctionality. Low frequency of active monocytes or reduced expression of human leukocyte antigen (HLA)-DR on monocytes shows the suppressed immune response in sepsis patients. One of the well-studied markers in patients with sepsis is procalcitonin (PCT). The role of monocytic (m) HLA-DR expression has been monitored in sepsis and is being considered a marker of the severity of interim immuno-depression in these patients. The study describes the impact of HLA-DR expression on monocytes quantitatively using flow cytometry.

METHODS

In this prospective study, we quantified monocytes and their HLA-DR expression in 20 patients of sepsis admitted to the Intensive Care Unit (ICU). Serum levels of PCT and interleukin (IL)-6 production were also measured in these patients, and the results were compared with those in healthy controls.

RESULTS

Monocyte frequency calculated was higher in sepsis patients as compared to healthy controls, however, HLA-DR expressing monocytes were significantly reduced as was the mean fluorescence intensity (MFI) of HLA-DR. Contrastingly, IL-6 and PCT levels were significantly high in sepsis than controls. The results suggest that low HLA-DR expression, combined with PCT, is a better prognostic parameter in the early phase of sepsis.

CONCLUSION

Poor recovery of mHLA-DR may serve as an early guide for clinicians to assess the prognosis of sepsis patients and consider immunomodulatory therapy in its management.

The Procalcitonin-guided Antibiotics in Respiratory Infections (PARI) project in general practice – a study protocol

Background

Antibiotic resistance is a global health challenge and the close correlation between antibiotic use and the development of resistance makes it essential to maintain a rational use of antibiotics. Most antibiotics are prescribed in general practice against acute respiratory tract infections (ARTI), even though most of these infections are of viral etiology. Thus, a safe method to substantially reduce unnecessary use of antibiotics in general practice is needed. Procalcitonin (PCT) is a precursor protein with very low circulating levels in the blood under physiological conditions. However, in response serious bacterial infection the level of PCT in the blood may increase significantly. Until recently, quantitative analyses of PCT was performed in hospital laboratories, impeding the implementation of PCT in primary care. Our aim is to determine whether it is possible to lower the use of antibiotics in patients presenting with symptoms of ARTI, without significantly prolonging the period of illness, by using a newly released PCT point-of-care test in general practice.

Methods

The Procalcitonin-Guided Antibiotics in Respiratory Infections (PARI) study is a randomized, single-blinded, non-inferiority, multi-practice intervention study comparing a PCT-group to a control group. Patients (N = 508) will be randomly assigned 1:1 to standard care or to the PCT group. The primary outcomes the duration of illness and symptoms from ARTI measured with the Acute Respiratory Tract Infection Questionnaire. Secondary outcomes include (1) Number of participants in each trial arm exposed to antibiotic treatment at index consultation (day 1) and within 30 days, (2) Number of participants in each trial arm with side effects from antibiotic treatment within 14 days, (3) Number of participants in each trial arm with re-consultations within 30 days, (4) Number of participants in each trial arm admitted to hospital (including diagnosis and mortality) within 30 days, (5) Characterization of biomarker (CRP and PCT) level at index consultation. Tertiary outcomes include patient and general practitioner satisfaction with the use of the PCT point-of-care test, and long-term follow-up.

Discussion

To our knowledge, this is the first study to examine a PCT point-of-care test in general practice with the aim of reducing the use of antibiotics in patients with symptoms of ARTI. Results of this study may prove important in targeting antibiotic treatment only to those patients who need it, thus contributing to limiting the spread of antibiotic resistance.

Trial registration

ClinicalTrials.gov Identifier: NCT04216277, date of registration: 2. of January 2020.

Post-operative kinetics of C-reactive protein to distinguish between bacterial infection and systemic inflammation in infants after cardiopulmonary bypass surgery: the early and the late period

OBJECTIVES

Differentiation between post-operative inflammation and bacterial infection remains an important issue in infants following congenital heart surgery. We primarily assessed kinetics and predictive value of C-reactive protein for bacterial infection in the early (days 0-4) and late (days 5-28) period after cardiopulmonary bypass surgery. Secondary objectives were frequency, type, and timing of post-operative infection related to the risk adjustment for congenital heart surgery score.

METHODS

This 3-year single-centre retrospective cohort study in a paediatric cardiac ICU analysed 191 infants accounting for 235 episodes of CPBP surgery. Primary outcome was kinetics of CRP in the first 28 days after CPBP surgery in infected and non-infected patients.

RESULTS

We observed 22 infectious episodes in the early and 34 in the late post-operative period. CRP kinetics in the early post-operative period did not accurately differentiate between infected and non-infected patients. In the late post-operative period, infected infants displayed significantly higher CRP values with a median of 7.91 (1.64-22.02) and 6.92 mg/dl (1.92-19.65) on days 2 and 3 compared to 4.02 (1.99-15.9) and 3.72 mg/dl (1.08-9.72) in the non-infection group. Combining CRP on days 2 and 3 after suspicion of infection revealed a cut-off of 9.47 mg/L with an acceptable predictive accuracy of 76%.

CONCLUSIONS

In neonates and infants, CRP kinetics is not useful to predict infection in the first 72 hours after CPBP surgery due to the inflammatory response. However, in the late post-operative period, CRP is a valuable adjunctive diagnostic test in conjunction with clinical presentation and microbiological diagnostics.

Risk factors and predictive markers for early and late-onset neonatal bacteremic sepsis in preterm and term infants

BACKGROUND

The early detection and prediction of bacteremic sepsis in preterm and term neonates remains a challenging task because of their nonspecific clinical presentations. We aimed to investigate the risk factors associated with bacteremia and find the cutoff values of predictive markers to achieve accurate diagnosis of neonatal bacteremic sepsis.

METHODS

Not-doing-well preterm and term neonates with suspected sepsis were retrospectively enrolled between January 2015 and December 2017 in Taipei Veterans General Hospital. Blood culture, hemogram, serum procalcitonin (PCT), and C-reactive protein (CRP) were drawn at the onset of clinical signs and symptoms. All cases were divided to either early-onset or late-onset groups according to postpartum age. Nonparametric statistic, logistic regression, and receiver operating characteristic analysis were performed to evaluate the risk factors and cutoff values for predicting bacteremia.

RESULTS

A total of 169 suspected sepsis episodes were analyzed, 68.0% of which had cardiopulmonary dysfunction and 19.5% had perinatal stress. The early-onset group had 123 (72.8%) patients, 4 of which had bacteremia and 119 had nonbacteremia conditions. The late-onset group had 46 (27.2%) patients, 8 of which had bacteremia and 38 had nonbacteremia conditions. Gestational age, birth body weight, Apgar score at 5 minutes, serum PCT, CRP, and platelet (PLT) count in the early-onset group and white blood cell (WBC) count in the late-onset group were substantially different between the patients with bacteremia and nonbacteremia conditions. PCT greater than 27 µg/L (adjusted odd ratio [aOR], 21.6; 95% CI, 1.1-435.1) and thrombocytopenia less than 100 × 109/L (aOR, 38.6; 95% CI, 1.4-1030.3) were predictive markers for bacteremia in the early-onset group.

CONCLUSION

Early- and late-onset neonatal sepsis had different risk factors and predictive markers of bacteremia. PCT and PLT count in the early-onset group and WBC count in the late-onset group were accurate diagnostic serum markers for neonatal bacteremic sepsis.

Impact of cardiopulmonary bypass and surgical complexity on plasma soluble urokinase-type plasminogen activator receptor levels after cardiac surgery

BACKGROUND

Circulating soluble urokinase plasminogen activator receptor (suPAR) is a marker of inflammation with prognostic value for elevated risk of morbidity and mortality. It has not yet been shown how the inflammatory process induced by cardiac surgery affects suPAR concentrations postoperatively.

METHODS

In a prospective observational study, plasma suPAR levels were measured in 30 patients undergoing cardiac surgery with cardiopulmonary bypass (CPB), pre-, peri, post-operatively, and 3-5 days after surgery. Fifteen patients underwent coronary artery bypass grafting (CABG) and 15 underwent complex procedures with longer CPB duration. Concentrations of suPAR at each time point were compared to the preoperative levels and compared between the two groups.

RESULTS

In both groups, plasma suPAR concentrations were significantly higher on the first postoperative day (3.27 (interquartile range (IQR) 2.75-3.86) µg/L compared to baseline (2.62 (1.98-3.86)) µg/L, p < .001. There were no significant differences in suPAR concentrations between the groups at any time point. Preoperatively, the median suPAR concentration was 2.57 (2.01-3.60) µg/L in the CABG group versus 2.67 (1.89-3.97) µg/L in the complex group (p = .567). At ICU arrival 2.48 (2.34-3.23) µg/L versus 2.73 (2.28-3.44) µg/L in CABG and complex patients, respectively (p = .914). There was no difference in suPAR concentrations between the groups on postoperative day 1 (3.34 (2.89-3.89) versus 3.19 (2.57-3.62) p = .967) or 3-5 days after surgery (2.72 (1.98-3.16) versus 2.96 (2.39-4.28) p = .085.

CONCLUSIONS

After a transient rise on the first postoperative day, the suPAR levels returned to the preoperative levels by the third postoperative day. There was no significant difference in suPAR levels between the routine CABG and complex group with longer CPB time.

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.

Prognostic Value of Procalcitonin for Morbidity and Mortality in Patients after Cardiac Surgery

Background

The increased serum procalcitonin (PCT) level in cardiac patients is known as a sign of postoperative complications.

Objective

Considering the importance of predicting the incidence of both complications and mortality caused by coronary artery bypass graft (CABG) surgery, this study was conducted to determine the serum PCT level and its relationship with one-year morbidity and mortality among CABG patients.

Methods

This descriptive-analytical study was performed on 100 patients who underwent CABG surgery in Vali-e-Asr Hospital of Birjand, Iran. They were selected by a census sampling method from March 2014 to March 2015. The Elecsys BRAHMS PCT kit (Roche Company) was then used to measure the patients' serum PCT level. The required data were collected using the patients' medical records and telephone interviews with the patient or his/her relatives by passing one year from their discharge. The outcomes of this study comprised of mortality and morbidity causes (e.g., dysrhythmia, infection, and stroke). The data were then analyzed in SPSS version 16 by Mann–Whitney, chi-squared, and Fisher exact tests.

Results

The postoperative serum PCT level is significantly correlated with sternum wound infection (p=0.001), packed cells (PC) transfusion (p=0.003), and death (p=0.003). In addition, a significant relationship was found between dyslipidemia and hypertension and early mortality rate in patients with high levels of PCT. Of note, risk-adjusted death did not differ significantly between the serum PCT levels after one year (RR, 0.068; 95% CI 0.008–0.566).

Conclusion

Higher PCT serum levels in CABG patients are associated with the increased early mortality rate, sternum wound infection, and PC transfusion. Additionally, the other factors associated with mortality in the patients under study included dyslipidemia and hypertension.

Cytokine Release Syndrome Associated with T-Cell-Based Therapies for Hematological Malignancies: Pathophysiology, Clinical Presentation, and Treatment

Cytokines are a broad group of small regulatory proteins with many biological functions involved in regulating the hematopoietic and immune systems. However, in pathological conditions, hyperactivation of the cytokine network constitutes the fundamental event in cytokine release syndrome (CRS). During the last few decades, the development of therapeutic monoclonal antibodies and T-cell therapies has rapidly evolved, and CRS can be a serious adverse event related to these treatments. CRS is a set of toxic adverse events that can be observed during infection or following the administration of antibodies for therapeutic purposes and, more recently, during T-cell-engaging therapies. CRS is triggered by on-target effects induced by binding of chimeric antigen receptor (CAR) T cells or bispecific antibody to its antigen and by subsequent activation of bystander immune and non-immune cells. CRS is associated with high circulating concentrations of several pro-inflammatory cytokines, including interleukins, interferons, tumor necrosis factors, colony-stimulating factors, and transforming growth factors. Recently, considerable developments have been achieved with regard to preventing and controlling CRS, but it remains an unmet clinical need. This review comprehensively summarizes the pathophysiology, clinical presentation, and treatment of CRS caused by T-cell-engaging therapies utilized in the treatment of hematological malignancies.

Effects of sugammadex on postoperative respiratory management in children with congenital heart disease: a randomized controlled study

BACKGROUND

Early extubation can reduce pulmonary complications in children undergoing cardiac surgery. The aim of this study is to evaluate the effects of sugammadex for postoperative respiratory management in children with congenital heart disease.

METHODS

Sixty children with congenital heart disease undergoing elective cardiac surgery were divided into group S and group C (30 children in each group). When post tetanic twitches count (PTC) = 1-2 and train-of-four (TOF) = 0, the children in group S received sugammadex4 mg/kg for reversal of neuromuscular block at the end of surgery, and the children in group C received the same volume of normal saline. The recovery time to TOF of 0.9, the mechanical ventilation and extubation times were recorded. On the other side, the hemodynamic parameters before and 5 min after administration, and side effects were also recorded. The levels of C-reactive protein (CRP) and procalcitonin (PCT) before and 24 h after surgery were measured.

RESULTS

The recovery time to TOF of 0.9 and extubation time were significantly shorter in the group S than in the group C (4.2 ± 1.4 vs 108.2 ± 26.7 min, 66.3 ± 6.5 vs 171.6 ± 23.1 min, respectively, P <  0.01). The CRP and PCT levels were found to be increased in both groups at postoperative 24 h than before surgery. Further, the levels of PCT and CRP at postoperative 24 h were lower in group S when compared to group C (median, 7 vs 17.5 mg/ml, 1.76 vs 5.22 ng/ml, respectively, P <  0.05). There were no statistical differences observed between the two groups (P> 0.05) with respect to side effects.

CONCLUSION

Sugammadex is rapid and effective in reversing rocuronium-induced neuromuscular block, and significantly reduces the extubation time and the release of postoperative CRP and PCT in children with congenital heart diseases.

Procalcitonin versus C-reactive protein: review of kinetics and performance for diagnosis of neonatal sepsis

Procalcitonin (PCT) and C-reactive protein (CRP) are commonly used biomarkers, but their diagnostic advantage for neonatal early-onset (EOS) or late-onset (LOS) sepsis is controversial. In a comprehensive literature review we found significant heterogeneity between studies in sample timing, cut-off values, consideration of blood culture results for sepsis classification, and definition of EOS versus LOS. We identified 39 studies directly comparing PCT with CRP, but only four in very low birth weight (VLBW) neonates. The mean sensitivity for EOS, LOS, and EOS + LOS was 73.6%, 88.9%, and 76.5% for PCT, compared to 65.6%, 77.4%, and 66.4% for CRP, respectively. Mean specificity of PCT and CRP was 82.8% versus 82.7% for EOS, 75.6% versus 81.7% for LOS, and 80.4% versus 91.3% for EOS + LOS. More studies directly comparing both biomarkers for EOS and LOS, especially in extremely and very-low-birth-weight infants, are needed to determine their clinical value for guidance of antibiotic therapy in neonatal sepsis.

Changes in the levels of inflammatory markers after transthoracic device closure of ventricular septal defects in pediatric patients

Background

Transthoracic device closure of ventricular septal defect (VSD) is widely used in the clinic, especially in China. Changes in inflammatory marker levels after transthoracic device closure of VSD in pediatric patients have not been reported.

Methods

We retrospectively collected clinical data for 85 pediatric patients in our hospital from September 2017 to January 2018. The patients were divided into two groups according to treatment (device group vs. surgical group). The clinical and experimental data from the two groups were statistically analyzed.

Results

Clinical outcomes were good in all patients without any fatal complications. Similar increasing trends in inflammatory markers (white blood cell (WBC) count, procalcitonin (PCT), C-reactive protein (CRP), and interleukin-6 (IL-6)) were found in the two groups, both of which showed noticeable systemic inflammatory responses. In addition, no significant difference in the postoperative levels of inflammatory markers was observed between these two groups.

Conclusions

Although transthoracic device closure of VSD seems to be less traumatic and involves a quicker recovery, it also induces a systemic inflammatory response as measured by WBC count and PCT, CRP and IL-6 levels, and the altered trends in inflammatory markers were similar to those of conventional surgery under CPB.

The Relationship Between Neutrophil to Lymphocyte Ratio and Clinical Outcome in Pediatric Patients After Cardiopulmonary Bypass Surgery: A Retrospective Study

Background: The aim of this study was to investigate the prognostic role of the neutrophil to lymphocyte ratio (NLR) in pediatric patients undergoing open-heart surgery with cardiopulmonary bypass (CPB). Methods: A retrospective cohort study of 61 pediatric patients who underwent CPB in the First Affiliated Hospital of Nanjing Medical University from January 2017 to October 2018 was conducted. All perioperative clinical data, including neutrophil count, lymphocyte count, and C-reactive protein (CRP), were collected retrospectively. The prognostic value of NLR and its association with extubation time, duration of intensive care unit (ICU) stay and in-hospital stay were analyzed. Results: Neutrophil count, NLR, and CRP were significantly increased post-operative compared with pre-operative (p < 0.05). The increased post-operative levels of NLR were significantly associated with longer extubation time, as well as prolonged post-operative cardiac ICU stay (p < 0.05). Multivariate linear regression analysis revealed that elevated NLR displayed a significant independent association with extubation time and the duration of an ICU stay. Conclusion: Increased post-operative NLR followed by cardiac surgery with CPB in pediatric patients was associated with longer extubation time and a longer duration of an ICU stay.

Use of biomarkers in pediatric sepsis: literature review

Despite advances in recent years, sepsis is still a leading cause of hospitalization and mortality in infants and children. The presence of biomarkers during the response to an infectious insult makes it possible to use such biomarkers in screening, diagnosis, prognosis (risk stratification), monitoring of therapeutic response, and rational use of antibiotics (for example, the determination of adequate treatment length). Studies of biomarkers in sepsis in children are still relatively scarce. This review addresses the use of biomarkers in sepsis in pediatric patients with emphasis on C-reactive protein, procalcitonin, interleukins 6, 8, and 18, human neutrophil gelatinase, and proadrenomedullin. Assessment of these biomarkers may be useful in the management of pediatric sepsis.

Procalcitonin Is a Better Biomarker than C-Reactive Protein in Newborns Undergoing Cardiac Surgery: The PROKINECA Study

OBJECTIVES

To assess the kinetics of procalcitonin (PCT) and C-reactive protein (CRP) in newborns after cardiothoracic surgery (CS), with and without cardiopulmonary bypass, and to assess whether PCT was better than CRP in identifying sepsis in the first 72 hours after CS.

PATIENTS AND METHODS

This is a prospective study of newborns admitted to the neonatal intensive care unit after CS.

INTERVENTIONS

PCT and CRP were sequentially drawn 2 hours before surgery and at 0, 12, 24, 48, and 72 hours after surgery.

RESULTS

A total of 65 patients were recruited, of which 14 were excluded because of complications. We compared the kinetics of PCT and CRP after CS in bypass and non-bypass groups without sepsis; there were no differences in the PCT values at any time (24 hours, P = 0.564; 48 hours, P = 0.117; 72 hours, P = 0.076). Thirty-five patients needed bypass, of whom four were septic (11.4%). Significant differences were detected in the PCT values on comparing the septic group to the nonseptic group at 48 hours after cardiopulmonary bypass (P = 0.018). No differences were detected in the CRP values in these groups. A suitable cutoff for sepsis diagnosis at 48 hours following bypass would be 5 ng/mL, with optimal area under the curve of 0.867 (confidence interval 0.709–0.958), P < 0.0001, and sensitivity and specificity of 87.5% (29.6–99.7) and 72.6% (53.5–86.4), respectively.

CONCLUSION

This is a preliminary study but PCT seems to be a good biomarker in newborns after CS. Values over 5 ng/mL at 48 hours after CS should alert physicians to the high risk of sepsis in these patients.

Procalcitonin is useful whereas C-reactive protein is not, to predict complications following coronary artery bypass surgery

Background: The respective value of procalcitonin (PCT) and C-reactive protein (CRP) as markers of postoperative complications after coronary bypass surgery is unclear. Therefore, complications during one week after surgery were studied to evaluate the predictive role of PCT and CRP changes during the immediate postoperative period.

Methods: Thirty-two patients, in whom an uneventful immediate postoperative course was anticipated, were prospectively enrolled and followed-up to the 7th postoperative day. At the end of the follow-up, patients were divided into two groups. Group A were patients with an uncomplicated postoperative course and Group B were patients with a complicated postoperative course.

Results: Serum samples were drawn for PCT and CRP determination after induction of anesthesia (baseline), at the end of surgery and daily until postoperative day 2. Baseline serum PCT concentrations were 0.119 ± 0.09 and 0.209 ± 0.21 ng/mL in Groups A and B, respectively (NS). Serum PCT concentration increased compared with baseline in both groups during the first two days after surgery. The increase in serum PCT concentration was significantly greater in Group B than A patients ( p<0.0002). Considering a perioperative abnormal cut-off value of > 0.5 ng/mL, there were none in Group A versus 57% in Group B ( p<0.0001). Baseline serum CRP concentrations were 1.449 ± 1.30 and 1.589 ± 1.35 ng/mL in Groups A and B, respectively (NS). After surgery, CRP increased significantly compared with baseline in both groups. When changes in time-varying variables were included in a logistic model, complications were predicted by changes (between baseline and end of surgery values) of PCT (coefficient=9.410; t=2.18) and heart rate (coefficient=0.075; t=1.57), whereas changes of CRP, white blood cells, mean blood and central venous pressures did not contribute statistically. The model constant was -4.827 (t= -2.43) and the ROC curve area was 0.8971. Thus, absolute PCT changes of 0.20, 0.40 and 0.60 ng/mL carry an approximate risk of 5, 26 and 69%, respectively, of postoperative complications in the time frame of this study.

Conclusions: A postoperative serum PCT concentration of >0.5 ng/mL is highly suggestive of a postoperative complication. CRP changes do not contribute to predictive information.

Procalcitonin as a biomarker of bacterial infection in pediatric patients after congenital heart surgery

Background:

Bacterial infection (BI) after congenital heart surgery (CHS) is associated with increased morbidity and is difficult to differentiate from systemic inflammatory response syndrome caused by cardiopulmonary bypass (CPB). Procalcitonin (PCT) has emerged as a reliable biomarker of BI in various populations.

Aim:

To determine the optimal PCT threshold to identify BI among children suspected of having infection following CPB.

Setting and Design:

Single-center retrospective observational study.

Materials and Methods:

Medical records of all the patients admitted between January 2013 and April 2015 were reviewed. Patients in the age range of 0-21 years of age who underwent CHS requiring CPB in whom PCT was drawn between postoperative days 0-8 due to suspicion of infection were included.

Statistical Analysis:

The Wilcoxon rank-sum test was used for nonparametric variables. The diagnostic performance of PCT was evaluated using a receiver operating characteristic (ROC) curve.

Results:

Ninety-eight patients were included. The median age was 2 months (25th and 75th interquartile of 0.1-7.5 months). Eleven patients were included in the BI group. The median PCT for the BI group (3.42 ng/mL, 25th and 75th interquartile of 2.34-5.67) was significantly higher than the median PCT for the noninfected group (0.8 ng/mL, 25th and 75th interquartile 0.38-3.39), P = 0.028. The PCT level that yielded the best compromise between the sensitivity (81.8%) and specificity (66.7%) was 2 ng/mL with an area under the ROC curve of 0.742.

Conclusion:

A PCT less than 2 ng/mL makes BI unlikely in children suspected of infection after CHS.

Procalcitonin: Is This the Promised Biomarker for Critically Ill Patients?

Objective Procalcitonin (PCT) has been increasingly used in the critical care setting to determine the presence of bacterial infection and also to guide antibiotic therapy. We reviewed PCT's physiologic role, as well as its clinical utility for the management of pediatric critically ill patients. Findings PCT is a precursor of the hormone calcitonin. Its production is induced by inflammatory conditions, especially bacterial infections. Literature shows that PCT is a moderately reliable diagnostic test for severe bacterial infection in children. Synthesis of available adult studies suggests that the use of PCT-based algorithms to support medical decision making reduces antibiotic exposure without compromising safety in critically ill patients. However, no study has addressed the usefulness and safety of PCT to guide antibiotic therapy in severely ill children. In pediatric patients with acute lower respiratory tract infections, the use of PCT-based algorithms also led to a safe decrease in antibiotic treatment duration. Conclusion PCT has demonstrated clinical utility in the pediatric critical care setting when used for the diagnosis of bacterial infections and to guide antibiotic use in children with acute lower respiratory tract infections. However, more research is needed in critically ill children to determine the utility of PCT-driven antibiotic therapy in this population.

Prevention of infectious complications after heart surgery in children: procalcitonin-guided strategy

Introduction

Infectious complications remain a significant problem of modern cardiac surgery. New prevention strategies, based on the pathogenesis of such complications occurring after cardiopulmonary bypass (CPB) procedures, should be evaluated.

Aim of the study

To evaluate the effectiveness of a procalcitonin (PCT)-guided strategy involving the use of IgM-enriched intravenous immunoglobulins (IVIGs) in children with congenital heart disease with systemic inflammation during the early postoperative period.

Material and methods

Sixty consecutive patients aged 25 (21-30) months who underwent cardiac surgery with CPB and had blood PCT levels > 2 ng/mL on the 1^st postoperative day were enrolled in this single-center prospective randomized clinical trial. The patients were randomized into two groups, comparable in terms of the severity of their initial condition, age, and CPB time. IgM-enriched IVIGs (Pentaglobin, Biotest Pharma GmbH, Germany) were administered during the first 3 postoperative days (5 mL/kg each day) in the study group (n = 30) in addition to the standard treatment, which was also provided to the control group (n = 30). The data are presented as medians with 25-75^th percentiles; they were compared by the Mann-Whitney U-test, and p values of < 0.05 were considered as statistically significant.

Results

Postoperatively, 1/30 (3.3%) patients in the study group and 8/30 (26.7%) in the control group suffered from infectious complications (study group: urinary tract infection [UTI] – 1; control group: pneumonia – 4, pneumonia and sepsis – 2, peritonitis with multiorgan failure – 1, UTI – 1), p = 0.03. The length of hospital stay in the study group was shorter than in the control group: 19 (16-23) days vs. 24 (19-29) days, p = 0.002, as was the length of intensive care unit (ICU) stay: 3 (2-4) days vs. 4 (2-8) days, p = 0.03.

Conclusions

High PCT levels on the 1st postoperative day are associated with an increased risk of infectious complications after cardiac surgery. Early administration of IgM-enriched IVIGs can prevent the development of infectious complications.

Kinetics of C-reactive protein in children with congenital heart diseases in the early period after cardiosurgical treatment with extracorporeal circulation

PURPOSE

The aim of the study was to assess postoperative C-reactive protein (CRP) serum kinetics in children without clinical signs of infection after atrial and ventricular septal defects closure in terms of extracorporeal circulation (ECC).

MATERIAL/METHODS

Fifty-two patients met inclusion criteria and were divided into 2 groups: group A (antibiotic prophylaxis with cefazolin given up to 48 h postoperatively) and group B (antibiotic prophylaxis with amoxicillin and clavunic acid given more than 48 h postoperatively). The CRP was measured perioperatively in both groups. The CRP evaluation was the part of routine lab-tests during perioperative period, without any modification of the typical perioperative strategy. In the postoperative period CRP was measured after 24h, 48 h, 72 h and 96 h in both groups.

RESULTS

There were no differences between CRP levels between both groups of patients. The peak CRP values were observed after 48 h after the operation in ECC in both groups and decreased in the next postoperative days.

CONCLUSIONS

In children with congenital heart defects undergoing cardiosurgical treatment with the use of ECC the assessing CRP values in the first postoperative day remains questionable. The maximum peak CRP value after operation with ECC can be much higher than the reference values without infection complications. Single CRP assessment in early postoperative period in these groups of children can lead to over-diagnosis of infections and antibiotics abuse.

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.

Can we improve the outcomes of pediatric congenital heart disease survivors?

Appreciating the complexity and evolving pathophysiology after palliation of CHD is critical to improving the outcome. Despite a growing patient population because of greater survival over the years, detailed data on the long-term outcomes of these patients is surprisingly sparse. The establishment in 2001 of the Pediatric Heart Network by the National Heart, Lung and Blood Institute has provided a collaborative multicenter platform to conduct large trials in CHD and to characterize outcomes. This chapter has emphasized how CHD care spans the continuum from fetal life to adulthood. Current research efforts aspire to better characterize short-term and long-term outcomes, continue advancement of technologies to better diagnose and treat CHD, and to elucidate the role of genetics and biomarkers in predicting outcome. Focused studies on variations in perioperative practice and quality will help us provide better clinical outcomes for CHD survivors.

Procalcitonin in pediatrics

Over the past two decades, the body of literature on the clinical usefulness of procalcitonin (PCT) in adults has grown rapidly. Although this approach has led to increased insight, it has also prompted debate regarding its potential use in diagnosis and management of severe infection. Clinicians, however, are less familiar with the use of PCT in pediatric populations. In this review, we examine PCT as a marker of severe clinical pediatric conditions including its role in systemic inflammation, infection, and sepsis.

Approach to postoperative fever in pediatric cardiac patients

Fever in the postoperative period in children undergoing surgery for congenital heart disease is fairly common and tends to cause anxiety to both the surgeon and the patient. Such fever is associated with the metabolic response to trauma, systemic response to the cardiopulmonary bypass, hypothermia, presence of drainage tubes, drugs, blood transfusion as well as infections. Establishing the diagnosis requires proper assessment of the patient with focused history, targeted physical examination and judicious use of investigations with the knowledge of the common causes.

The profile of the systemic inflammatory response in children undergoing ventricular assist device support

OBJECTIVES

Serum C-reactive protein (CRP) has been used as a systemic inflammatory response (SIR) marker in the critical ill, including children after cardiopulmonary bypass surgery. Ventricular assist devices (VAD) have been increasingly used as a bridge support to heart transplantation in children. We aimed to examine the profiles of CRP in children receiving VAD support.

METHODS

Charts of 13 children receiving Berlin Heart EXCOR(®) from 2005 to 2009 were reviewed. The data obtained prior to and during VAD support included: CRP, white blood cells, inotropes and steroid use, VAD mode and duration of VAD support. Ten patients received left VAD (LVAD) and 3 biventricular VAD (BiVAD).

RESULTS

The median duration of VAD support was 59 days (ranged 3-678 days). Pre-VAD CRP was 35 ± 51 mg/l and increased to 109 ± 59 mg/l on days 1-3 after the VAD implantation (P = 0.01), then gradually decreased to 28 ± 28 mg/l by 4 months and normalized by 5 months (P < 0.0001). CRP was higher in BiVAD than in LVAD patients throughout the study period (P = 0.003). CRP positively correlated with the doses of the epinephrine and norepinephrine and the monocyte counts, and negatively correlated with the lymphocyte count. The lymphocyte count was 2.5 ± 0.4 x 10(9)/l prior to implantation, and decreased to 2.1 ± 1.3 x 10(9)/l on days 1-3 (P = 0.5) and then to 0.6 ± 0.1 x 10(9)/l by 6 months (P = 0.08). It tended to be lower in BiVAD patients (P = 0.06).

CONCLUSIONS

SIR exists in children prior to VAD support. VAD implantation is associated with a significant and prolonged increase in CRP and a decrease in lymphocyte count, indicating a suppressed immune function, being more pronounced in BiVAD patients.

The profile of inflammatory and metabolic response in children undergoing heart transplantation

Inflammatory and metabolic response is an important factor to determine clinical outcomes. However, it remains unknown in children undergoing heart transplantation (HTx). We examined the perioperative changes in the inflammatory and metabolic response markers C-reactive protein (CRP) and prealbumin (PA) in 38 heart-transplanted children. Data obtained prior to and within one month after HTx included CRP, PA, total and differential white blood cell counts, doses of inotropes and immunosuppressants, cultures of blood and body fluids, duration of cardiopulmonary bypass (CPB), aortic cross clamp and donor heart ischemia, and days in the intensive care unit (ICU) and hospital. CRP was 32±49 mg/L before HTx, increased to 130±55 mg/L on postoperative day 1-2, and decreased to 21±31 mg/L by one month after HTx. PA was 0.15±0.06 g/L before HTx, decreased to 0.12±0.03 g/L on postoperative day 1-2, and then gradually increased to 0.21±0.10 g/L by one month after HTx. Postoperative CRP positively correlated with epinephrine dosage and CPB duration. PA positively correlated with age. In conclusion, inflammatory and metabolic response is present before HTx and acutely intensified after HTx. It may be mainly influenced by CPB duration and cardiovascular function status.

Procalcitonin level as an aid for the diagnosis of bacterial infections following pediatric cardiac surgery

PURPOSE

The aim of the present study was to determine if blood procalcitonin can serve as an aid to differentiate between bacterial and nonbacterial cause of fever in children after cardiac surgery.

MATERIALS AND METHODS

A nested case-control study of children who underwent open cardiac surgery in critical care units of fourth-level pediatric hospital was performed. Blood samples for procalcitonin level were collected 1 day before operation; 1 hour postoperation; on postoperative days 1, 2, and 5; and on the day of fever, when it occurred.

RESULTS

Of 665 children who underwent cardiac bypass surgery, 126 had a febrile episode postoperatively, 47 children with a proven bacterial infection and 79 without bacterial infection. Among the 68 children in whom fever developed within the first 5 postoperative days, procalcitonin level at fever day was significantly higher in those with bacterial infection (n = 16) than in those without infection (n = 52). Similarly, among the 58 children in whom fever developed after day 5 postoperation, a significant difference was found in procalcitonin level at fever day between those with (n = 31) and without (n = 27) bacterial infection.

CONCLUSION

During the critical early and late periods after cardiac surgery in children, procalcitonin level may help to differentiate patients with bacterial infection from patients in whom the fever is secondary to nonbacterial infectious causes.

C-reactive protein in the diagnosis of postoperative infection in pediatric patients: a prospective observational study of 103 patients

BACKGROUND

Surgical stress elicits a systemic inflammatory response syndrome that contributes to the development of septic complications. C-reactive protein (CRP) is an acute phase protein released in inflammatory states. To analyze the usefulness of CRP as a marker of infection in surgical pediatric patients, we analyzed its kinetics in these patients in comparison with usual markers, such temperature, leukocytes, or fibrinogen.

METHODS

One hundred three pediatric patients undergoing major surgery were enrolled consecutively in this observational study. C-reactive protein, leukocytes, neutrophils, platelets, fibrinogen, glycemia, and temperature were determined daily after surgery. Patients were classified as infected or not infected. Sensitivity, specificity, positive predictive value, negative predictive value, efficiency, precocity, positive likelihood ratio, and number of subjects to be treated were calculated.

RESULTS

Peak in CRP was detected at 48 ± 24 hours. C-reactive protein was higher in the infected group from the first day, with significant differences between groups from the second day. Best cutoff for detecting infection was increases in CRP of 11 mg/dL in 48 hours, with a sensitivity of 87%, specificity of 89%, precocity of 1.7 days (0.82-2.54), number of subjects to be treated of 1.7 (1.4-2.6), and positive likelihood ratio of 7.9. Application of other markers alone or in combination did not surpass the sensitivity, specificity, or precocity for increases in CRP of 11 mg/dL in 48 hours.

CONCLUSIONS

Increases of CRP constitute an easy and cheap prognostic alert system and may be used to establish strategies aimed to detect infection in surgical pediatric patients.

Procalcitonin as a marker of bacterial infection in children undergoing cardiac surgery with cardiopulmonary bypass

BACKGROUND

Owing to systemic inflammatory response syndrome, the diagnosis of post-operative infection after cardiopulmonary bypass is difficult to assess in children with the usual clinical and biological tools. Procalcitonin could be informative in this context.

METHODS

Retrospective study in a paediatric intensive care unit. Blood samples were collected as soon as infection was clinically suspected and a second assay was performed 24 hours later. Using referenced criteria, children were retrospectively classified into two groups: infected and non-infected.

RESULTS

Out of the 95 children included, 14 were infected. Before the third post-operative day, procalcitonin median concentration was significantly higher in the infected group than in the non-infected group - 20.24 nanograms per millilitre with a 25th and 75th interquartile of 15.52-35.71 versus 0.72 nanograms per millilitre with a 25th and 75th interquartile of 0.28 to 5.44 (p = 0.008). The area under the receiver operating characteristic curve was 0.89 with 95% confidence intervals from 0.80 to 0.97. The best cut-off value to differentiate infected children from healthy children was 13 nanograms per millilitre with 100% sensitivity - 95% confidence intervals from 51 to 100 - and 85% specificity - 95% confidence intervals from 72 to 91. After the third post-operative day, procalcitonin was not significantly higher in infected children - 2 nanograms per millilitre with a 25th and 75th interquartile of 0.18 to 12.42 versus 0.37 nanograms per millilitre with a 25th and 75th interquartile of 0.24 to 1.32 (p = 0.26). The area under the receiver operating characteristic curve was 0.62 with 95% confidence intervals from 0.47 to 0.77. A procalcitonin value of 0.38 nanograms per millilitre provided a sensitivity of 70% with 95% confidence intervals from 39 to 89 for a specificity of 52% with 95% confidence intervals from 34 to 68. After the third post-operative day, a second assay at a 24-hour interval can improve the sensitivity of the test.

CONCLUSIONS

Procalcitonin seems to be a discriminating marker of bacterial infection during the post-operative days following cardiopulmonary bypass in children.

Time course of C-reactive protein and inflammatory mediators after neonatal surgery

OBJECTIVE

To characterize the perioperative course of C-reactive protein (CRP) and inflammatory mediators in neonates ≤44 weeks' corrected gestational age.

STUDY DESIGN

Prospective study of CRP and inflammatory mediators interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α in 55 neonates undergoing thoracic or abdominal surgery.

RESULTS

In the absence of infection, CRP increased after surgery, peaking on post-operative day 2. The perioperative patterns of CRP differed by diagnosis and inflammatory state. Surgery alone did not cause an increase in CRP because in 13 of 55 infants (24%), CRP remained <1.0 mg/dL at all time points. For thoracic procedures, patent ductus arteriosus ligation showed the least post-operative increase in CRP, and patients undergoing repair of congenital diaphragmatic hernia or tracheoesophageal fistula had a greater response. Abdominal procedures with low CRP response included repair of imperforate anus and pyloric stenosis, while gastroschisis repair and bowel reanastomosis after necrotizing enterocolitis were accompanied by a robust CRP response. IL-6 concentrations peaked on post-operative day 1 and correlated with the post-operative day 2 CRP peak (r=0.398, P=.004). The additional inflammatory mediators measured were not informative.

CONCLUSIONS

The range and time course of perioperative CRP differ by diagnosis. Serial measurements may be more informative than CRP magnitude.

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

Fever after cardiac surgery in children may be due to bacterial infection or noninfectious origin like systemic inflammatory response syndrome (SIRS) secondary to bypass procedure. A marker to distinguish bacterial from nonbacterial fever in these conditions is clinically important. The purpose of our study was to evaluate, in the early postcardiac surgery period, whether serial measurement of C-reactive protein (CRP) and its change over time (CRP velocity) can assist in detecting bacterial infection. A series of consecutive children who underwent cardiac surgery with bypass were tested for serum levels of CRP at several points up to 5 days postoperatively and during febrile episodes (>38.0°C). Findings were compared among febrile patients with proven bacterial infection (FWI group; sepsis, pneumonia, urinary tract infection, deep wound infection), febrile patients without bacterial infection (FNI group), and patients without fever (NF group). In all, 121 children were enrolled in the study, 31 in the FWI group, 42 in the FNI group, and 48 patients in the NF group. Ages ranged from 4 days to 17.8 years (median 19.0, mean 46 ± 56 months). There was no significant difference among the groups in mean CRP level before surgery, 1 hour, and 18 hours after. A highly significant interaction was found in the change in CRP over time by FWI group compared with FNI group (P < .001). Mean CRP velocity ([fCRP - 18hCRP]/[fever time (days) - 0.75 day]) was significantly higher in the infectious group (4.0 ± 4.2 mg/dL per d) than in the fever-only group (0.60 ± 1.6 mg/dL per d; P < .001). A CRP velocity of 4 mg/dL per d had a positive predictive value (PPV) of 85.7% for bacterial infection with 95.2% specificity. Serial measurements of CRP/CRP velocity after cardiac surgery in children may assist clinicians in differentiating postoperative fever due to bacterial infection from fever due to noninfectious origin.

[Kinetics of C-reactive protein and procalcitonin after paediatric cardiac surgery]

INTRODUCTION AND OBJECTIVES

The systemic inflammatory response syndrome developed after cardiac surgery impedes the detection of complications. The aim of our study was to examine the behaviour of C-reactive protein (CRP) and procalcitonin (PCT), as well as to evaluate its relationship with severity and to analyse its usefulness in the identification of complications.

METHODS

A total of 59 children who underwent cardiac surgery with cardiopulmonary bypass were prospectively studied. CRP and PCT were determined after surgery and at 24, 48 and 72 hours. The relationships between both parameters and the clinical severity were analysed (evaluated with PRISM and TISS scoring systems), as well as with the incidence of complications (infectious and haemodynamics).

RESULTS

Serum concentrations of CRP and PCT increased in the first 24 hours after surgery, with a gradual decrease over the following days. There was no association between CRP and severity or development of complications. A moderate correlation was observed between PCT after surgery, at 24 and 48 hours, and PRISM (r=0.548; 0.434 and 0.446) and a low correlation between PCT and TISS. When studying the identification of complications, we obtained cut-off values of PCT>0.17ng/ml (Ss 73.3%; Sp 72.2%) and PCT>1.98ng/ml (Ss 57.1%; Sp 87%) immediately and 48 hours after surgery. No differences were found in CPR and PCT levels among patients with infectious and haemodynamics complications.

CONCLUSIONS

CPR does not correlate with the severity or the incidence of complications after paediatric cardiac surgery. PCT correlates with clinical severity and may be able to detect post-surgical complications.

Biomarkers for pediatric sepsis and septic shock

Sepsis is a clinical syndrome defined by physiologic changes indicative of systemic inflammation, which are likely attributable to documented or suspected infection. Septic shock is the progression of those physiologic changes to the extent that delivery of oxygen and metabolic substrate to tissues is compromised. Biomarkers have the potential to diagnose, monitor, stratify and predict outcome in these syndromes. C-reactive protein is elevated in inflammatory and infectious conditions and has long been used as a biomarker indicating infection. Procalcitonin has more recently been shown to better distinguish infection from inflammation. Newer candidate biomarkers for infection include IL-18 and CD64. Lactate facilitates the diagnosis of septic shock and the monitoring of its progression. Multiple stratification biomarkers based on genome-wide expression profiling are under active investigation and present exciting future possibilities.

The relationship between inflammatory activation and clinical outcome after infant cardiopulmonary bypass

BACKGROUND

Cardiopulmonary bypass (CPB) induces a systemic inflammatory response. The magnitude and consequences in infants remain unclear. We assessed the relationship between inflammatory state and clinical outcomes in infants undergoing CPB.

METHODS

Plasma concentrations of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor α, IL-1β, and C-reactive protein (CRP) were measured pre-CPB and immediately post-CPB, and at 6, 12, and 24 hours post-CPB in infants ≤9 months old. Perioperative clinical data were collected prospectively.

RESULTS

Diagnoses of 93 patients included transposition of the great arteries (40), tetralogy of Fallot (28), ventricular septal defect (21), truncus arteriosus (2), and complete atrioventricular canal (2). The median age was 37 days (range = 2 to 264). Pre-CPB IL-6 and CRP were higher in younger infants but were not associated with postoperative inflammatory mediator concentrations or measured clinical outcomes. IL-6 increased post-CPB (median 3.2 pg/mL pre-CPB, 24.2 post-CPB, 95.4 at 6 hours, and 90.3 at 24 hours; all P < 0.001). CRP increased post-CPB, peaking at 24 hours (median 27.5 at 24 hours, 0.3 pre-CPB; P < 0.001). IL-10 and IL-8 increased immediately post-CPB. After adjusting for age and diagnosis, postoperative IL-6 and IL-8 correlated with intensive care unit length of stay and postoperative blood product administration and, for IL-8, 24-hour lactate.

CONCLUSIONS

Greater preoperative cytokine and CRP production in younger infants did not correlate with postoperative outcomes; correlation between postoperative inflammatory mediator production and clinical course was statistically significant but clinically modest. We conclude that in infants undergoing low-to-moderate-complexity cardiac surgery in a single high-volume center, the contribution of inflammatory mediator production to postoperative morbidity is relatively limited.

Serum concentrations of procalcitonin after cardiac surgery

BACKGROUND AND AIM

Monitoring of complications in patients undergoing cardiac surgery may be difficult because cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome because of exposure of blood to nonphysiological surfaces. The purpose of the study was to establish the baseline levels of procalcitonin (PCT) after cardiac surgery in our population in order to analyze a possible induction of the inflammatory response that might interfere with the diagnosis of infection by PCT.

METHODS

Serum samples from patients undergoing coronary artery bypass grafting or valve replacement were collected at the time of admission to intensive care unit, after surgery as well as in the first and second postoperative days. Patients were followed for the development of postoperative complications. PCT levels were measured by immunoluminometric assay.

RESULTS

The mean PCT values were significantly higher in the first postoperative day in all the groups except the control group. No increased PCT levels were found related neither to duration of CPB, nor to time of aortic clamping. Only patients who presented complications had significantly increased PCT values immediately after surgery (p = 0.004), in the first postoperative day (p < 0.0001), and in the second postoperative day (p < 0.0001) with respect to those who recovered uneventfully.

CONCLUSIONS

A slight and transient increase in PCT levels was observed in the first postoperative day after cardiac surgery. Significant elevation of PCT was only observed when complications were present.

Procalcitonin versus C-reactive protein and immature-to-total neutrophil ratio as markers of infection after cardiopulmonary bypass in children

OBJECTIVE

To document concentrations of procalcitonin (PCT), C-reactive protein (CRP), and immature-to-total neutrophil ratio (ITR), postcardiopulmonary bypass (CPB), and to test the hypothesis that PCT is a more reliable marker of infection than CRP or ITR in the post-CPB child.

DESIGN

Prospective cohort study.

SETTING

Pediatric intensive care units at Royal Children's Hospital, Melbourne, Australia and Birmingham Children's Hospital, UK.

PATIENTS

First stage: 283 post-CPB children; second stage: 65 post-CPB children with suspected infection.

INTERVENTIONS

In the first stage, PCT, ITR, and CRP were measured serially on the first, second, third, and fifth postoperative day (POD). In the second stage, PCT, ITR, and CRP were measured in the specimens taken in the period before and after the clinical diagnosis of infection.

MEASUREMENTS AND MAIN RESULTS

In children without infection, the median peak PCT concentration more than 5 PODs was 1.0 ng/mL, in children with local infection 1.0 ng/mL, and in children with definite sepsis 14.8 ng/mL. CRP increased in all subgroups of children studied, reaching a peak on POD 3 (median 51 mg/L). In definite sepsis, CRP was increased more than the other subgroups. ITR remained high with a median of 0.08 from POD 1 and gradually decreased, except in definite sepsis, where it remained high. In a receiver operating characteristic curve analysis, PCT was the most reliable variable for the diagnosis of probable/definite sepsis with area under the curve 0.84 (95% confidence interval, 0.75-0.92) compared with 0.73 (0.62-0.84) for ITR and 0.62 (0.52-0.73) for CRP.

CONCLUSIONS

CRP was a poor marker of sepsis in this study. Children with a PCT <2.2 ng/mL or ITR <0.08 were unlikely to have definite or probable sepsis. However, only a third of children with high values of PCT and ITR had definite or probable sepsis.

Is C-reactive protein a biomarker for immediate clinical outcome after cardiac surgery?

OBJECTIVE

The purpose of this study was to determine the possible correlation between inflammatory activation after cardiac surgery with cardiopulmonary bypass, measured by postoperative C-reactive protein concentrations, and immediate intensive care unit outcome.

DESIGN

A prospective, clinical cohort study.

SETTING

A 10-bed surgical intensive care unit at a tertiary university hospital.

PATIENTS

Two hundred sixteen consecutive patients undergoing nonemergency cardiac surgery with cardiopulmonary bypass.

MEASUREMENTS AND MAIN RESULTS

Parsonnet and Acute Physiology and Chronic Health Evaluation scores, characteristics of the surgical intervention, intensive care unit length of stay, and mortality were recorded along with the following variables: cardiac (hours requiring inotropic support and new atrial fibrillation), respiratory (oxygenation index and hours requiring intubation), renal (difference between serum creatinine at admission and maximum creatinine), and analytic (C-reactive protein at admission and 6, 24, and 48 hours later; troponin I; CK-MB; and lactate).

RESULTS

Postoperative C-reactive protein concentrations did not correlate with variables such as time requiring inotropic support or intubation, oxygenation index, delta serum creatinine, and intensive care unit length of stay (with the exception of cardiopulmonary bypass time and the more frequent norepinephrine requirement in patients with higher C-reactive protein concentration at 48 hours); nor did C-reactive protein correlate with the analytic variables (with the exception of the lactate peak and C-reactive protein concentrations at 24 and 48 hours). There was no correlation between C-reactive protein and postoperative variables for coronary artery bypass graft surgery and valvular groups analyzed separately.

CONCLUSION

Postoperative C-reactive protein does not seem to be a useful marker in predicting outcome after 48 hours in the intensive care unit.

Correlation of procalcitonin and cytokine expression with dehiscence of wartime extremity wounds

BACKGROUND

Despite technological advances in the treatment of severe extremity trauma, the timing of wound closure remains the subjective clinical decision of the treating surgeon. Traditional serum markers are poor predictors of wound-healing. The objective of this study was to evaluate the cytokine and chemokine profiles of severe extremity wounds prior to closure to determine if wound effluent markers can be used to predict healing.

METHODS

Serum and effluent (exudate) samples were collected prospectively from adult volunteers with multiple high-energy penetrating extremity wounds sustained during military combat. Samples were collected prior to definitive wound closure or flap coverage. Wounds were followed clinically for six weeks. The primary clinical outcome measures were wound-healing and dehiscence. Control serum samples were collected from normal age and sex-matched adult volunteers. All samples were analyzed for the following cytokines and chemokines: procalcitonin; eotaxin; granulocyte macrophage colony stimulating factor; interferon (IFN)-gamma; interleukin (IL)-1 through 8, 10, 12, 13, and 15; IFN-gamma inducible protein-10; monocyte chemotactic protein-1; macrophage inflammatory protein-1alpha; the protein regulated on activation, normal T expressed and secreted (RANTES); and tumor necrosis factor (TNF)-alpha.

RESULTS

Fifty wounds were analyzed in twenty patients. Four of the fifty wounds dehisced. An increased rate of wound dehiscence was observed in patients with a concomitant closed head injury as well as in those with an associated arterial injury of the affected limb (p < 0.05). Among the serum chemokines and cytokines, only serum procalcitonin levels correlated with wound dehiscence (p < 0.05). Effluent analysis showed that, compared with wounds that healed, wounds that dehisced were associated with elevated procalcitonin, decreased RANTES protein, and decreased IL-13 concentrations (p < 0.05). No wound with an effluent procalcitonin concentration of <220 pg/mL, an IL-13 concentration of >12 pg/mL, or a RANTES protein concentration of >1000 pg/mL failed to heal.

CONCLUSIONS

Effluent procalcitonin, IL-13, and RANTES protein levels as well as serum procalcitonin levels correlate with wound dehiscence following closure of severe open extremity wounds. These preliminary results indicate that effluent biomarker analysis may be an objective means of determining the timing of traumatic wound closure.

New diagnostic and prognostic markers of ventilator-associated pneumonia

PURPOSE OF REVIEW

The purpose of this review is to analyze the potential advantages and drawbacks of using biomarkers of bacterial infection for the diagnosis and prognosis of ventilator-associated pneumonia.

RECENT FINDINGS

Whereas procalcitonin and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) have both greater diagnostic accuracies than most commonly used clinical parameters and other biomarkers of infection, such as C-reactive protein, they can be increased in noninfectious conditions or remain low in patients with true infection. Furthermore, these assays cannot determine the causative organisms and associated patterns of antibiotic susceptibility.

SUMMARY

Procalcitonin and sTREM-1 should be used only as a complementary tool, to reinforce the usual diagnostic work-up. However, serial serum procalcitonin and sTREM-1 measurements may provide an opportunity to change the treatment early in the course of patients with ventilator-associated pneumonia, either to intensify treatment when their levels stay high, or to avoid unnecessary prolonged courses of antibiotics when their levels rapidly decrease. Whether procalcitonin and/or sTREM-1 guidance can reduce antibiotic use in such a setting will require additional studies, but such a strategy appears promising.

Procalcitonin kinetics in pediatric patients with systemic inflammatory response after open heart surgery

OBJECTIVE

To evaluate procalcitonin and C-reactive protein as markers of inflammation severity and their value in predicting development of organ failure after pediatric open heart surgery.

DESIGN

Prospective, observational, clinical study.

SETTING

Single university hospital.

PATIENTS

Thirty-three pediatric patients with systemic inflammatory response syndrome (SIRS; n=19) and SIRS+organ failure (SIRS+OF; n=14) following open heart surgery were included.

MEASUREMENTS AND RESULTS

Plasma procalcitonin and C-reactive protein levels were measured before and after the operation, and 1, 2, 3, and 4 days after surgery. Patients were evaluated daily to assess organ failure. Postoperative procalcitonin levels in the SIRS+OF group were significantly higher than in the SIRS group. C-reactive protein levels were similar between the groups throughout the study period. Peak procalcitonin levels were found to be positively correlated with aortic cross-clamp and cardiopulmonary bypass times, duration of mechanical ventilation, intensive care unit and hospital stay, mortality and organ failure development. Peak procalcitonin was found to be a good predictor of postoperative organ failure development and mortality. However, the predictive value of peak C-reactive protein for organ failure and mortality was found to be weak. Double-peak procalcitonin curves were observed in SIRS+OF patients with infection during the intensive care unit stay.

CONCLUSION

In the SIRS+OF group peak procalcitonin levels were found to be highly predictive for mortality and organ failure development, whereas C-reactive protein levels were not. Daily procalcitonin measurements in SIRS+OF patients may help identify the postoperative infection during the follow-up period.

Procalcitonin does discriminate between sepsis and systemic inflammatory response syndrome

AIMS

To evaluate whether procalcitonin (PCT) and C reactive protein (CRP) are able to discriminate between sepsis and systemic inflammatory response syndrome (SIRS) in critically ill children.

METHODS

Prospective, observational study in a paediatric intensive care unit. Kinetics of PCT and CRP were studied in patients undergoing open heart surgery with cardiopulmonary bypass (CPB) (SIRS model; group I1) and patients with confirmed bacterial sepsis (group II).

RESULTS

In group I, PCT median concentration was 0.24 ng/ml (reference value <2.0 ng/ml). There was an increment of PCT concentrations which peaked immediately after CPB (median 0.58 ng/ml), then decreased to 0.47 ng/ml at 24 h; 0.33 ng/ml at 48 h, and 0.22 ng/ml at 72 h. CRP median concentrations remained high on POD1 (36.6 mg/l) and POD2 (13.0 mg/l). In group II, PCT concentrations were high at admission (median 9.15 ng/ml) and subsequently decreased in 11/14 patients who progressed favourably (median 0.31 ng/ml). CRP levels were high in only 11/14 patients at admission. CRP remained high in 13/14 patients at 24 h; in 12/14 at 48 h; and in 10/14 patients at 72 h. Median values were 95.0, 50.9, 86.0, and 20.3 mg/l, respectively. The area under the ROC curve was 0.99 for PCT and 0.54 for CRP. Cut off concentrations to differentiate SIRS from sepsis were >2 ng/ml for PCT and >79 mg/l for CRP.

CONCLUSION

PCT is able to differentiate between SIRS and sepsis while CRP is not. Moreover, unlike CRP, PCT concentrations varied with the evolution of sepsis.

Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

INTRODUCTION

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.

METHODS

We performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.

RESULTS

Uncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.

CONCLUSION

The dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.