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

Evaluating C-Reactive Protein and Procalcitonin Discordance Among Febrile Infants at Risk of Serious Bacterial Infections

AIM

We aimed to investigate the prevalence and factors associated with C-reactive protein (CRP) and procalcitonin (PCT) discordance in febrile infants with serious bacterial infections (SBIs).

METHODS

We performed a retrospective review of febrile infants ≤ 90 days old presenting to the emergency department between December 2018 and June 2023. We compared conservative and pragmatic thresholds for PCT (< 0.5 ng/mL and < 1.7 ng/mL) and CRP (< 10 mg/L and < 20 mg/L). Discordance was defined as normal CRP with abnormal PCT and vice versa. Performance was presented using sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

RESULTS

Among 3459 infants, 426 infants (12.3%) had SBIs, among whom 355 (83.3%) had both CRP and PCT performed. Overall, a conservative CRP threshold had the highest sensitivity (74.1%, 95% CI 69.2%-78.6%) and NPV (95.6%, 95% CI 94.6%-96.4%). Among those with SBIs, 148/355 (41.7%) had a normal PCT (< 1.7 ng/mL) and an abnormal CRP (≥ 20 mg/L), while 16/355 (4.5%) had a normal CRP (< 20 mg/L) and an abnormal PCT (≥ 1.7 ng/mL). An increased discordance, specifically abnormal CRP with normal PCT, was found in males, infants 29-90 days old, and those with urinary tract infections.

CONCLUSION

SBI clinical decision rules should consider CRP-PCT discordance in specific patient populations.

Early predictors of bacterial pneumonia infection in children with congenital heart disease after cardiopulmonary bypass: a single-centre retrospective study

OBJECTIVES

The objective of this study was to evaluate the early predictors of bacterial pneumonia infection in children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB).

DESIGN

Retrospective study.

SETTING

A freestanding tertiary paediatric hospital in China.

PARTICIPANTS

Patients admitted to the hospital due to CHD who underwent open-heart surgery.

OUTCOME MEASURES

We retrospectively reviewed and analysed data from 1622 patients with CHD after CPB from June 2018 to December 2020 at the Children's Hospital of Nanjing Medical University. Enrolled patients were assigned to an infection group or a non-infection group according to the presence of postoperative bacterial pneumonia infection, and the differences in clinical indicators were compared. Potential predictors were analysed by multivariate logistic regression analysis and area under the curve (AUC) analysis.

RESULTS

Among the 376 patients (23.2%) in the infection group, the three most common bacteria were Streptococcus pneumoniae in 67 patients (17.8%), Escherichia coli in 63 patients (16.8%) and Haemophilus influenzae in 53 patients (14.1%). The infection group exhibited a lower weight (8.0 (6.0-11.5) kg vs 11.0 (7.5-14.5) kg, p<0.001). In the infection group, procalcitonin (PCT) (ng/mL: 4.72 (1.38-9.52) vs 1.28 (0.47-3.74), p<0.001) and C reactive protein (CRP) (mg/L: 21.0 (12.1-32.0) vs 17.0 (10.0-27.0), p<0.001) levels were significantly greater than those in the non-infection group. Binary logistic regression analysis revealed that weight, PCT and CRP were independent risk factors for pulmonary bacterial infection after CPB. The AUCs of weight, PCT, CRP and PCT+CRP for predicting pulmonary bacterial infection after CPB were 0.632 (95% CI 0.600 to 0.664), 0.697 (95% CI 0.667 to 0.727), 0.586 (95% CI 0.554 to 0.618) and 0.694 (95% CI 0.664 to 0.724), respectively, and the cut-off values were ≤10.25 kg, ≥4.25 ng/mL, ≥6.50 mg/L and ≥0.20, respectively. The sensitivities were 69.7%, 54.0%, 93.9% and 70.2%, and the specificities were 53.5%, 77.7%, 19.4% and 59.1%, respectively.

CONCLUSIONS

In our study, weight, PCT and CRP were found to be independent predictors of pulmonary bacterial infection after CPB. Moreover, PCT was the most specific predictor, and CRP was the most sensitive independent predictor that might be beneficial for the early diagnosis of pulmonary bacterial infection after CPB in patients with CHD.

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.

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.

Infection…what else? The usefulness of procalcitonin in children after cardiac surgery

Objectives

Procalcitonin is a useful biomarker for predicting bacterial infection after cardiac surgery. However, sometimes procalcitonin rises following cardiac surgery without a confirmation of bacterial infection. The aim was to analyse procalcitonin levels in children without a bacterial infection after cardiac surgery.

Study design

This is a prospective, observational study of children <18 years old admitted to the pediatric intensive care unit after cardiac surgery.

Results

1,042 children were included, 996 (95.6%) without a bacterial infection. From them, severe complications occurred in 132 patients (13.3%). Procalcitonin increased differentially depending on the type of complication. Patients who presented a poor outcome (n = 26, 2.6%) had higher procalcitonin values in the postoperative period than the rest of patients (<24 hours: 5.8 ng/mL vs. 0.6 ng/mL; 24–48 hours, 5.1 ng/mL vs. 0.8 ng/mL, and 48–72 hours, 5.3 ng/mL vs. 1.2 ng/mL), but these values remained stable over time (p = 0.732; p = 0.110). The AUC for procalcitonin for predicting poor outcome was 0.876 in the first 24 hours. The cut-off point to predict poor outcome was 2 ng/mL in the first 24 hours (sensitivity 86.9%, specificity 77.3%). Patients with bacterial infection (n = 46) presented higher values of procalcitonin initially, but they decreased in the 48–72 hours period (<24 hours: 4.9 ng/mL; 24–48 hours, 5.8 ng/mL, and 48–72 hours, 4.5 ng/mL).

Conclusions

A procalcitonin value<2 ng/mL may indicate the absence of infection and poor outcome after cardiac surgery. The evolution of the values of this biomarker might help to discern between infection (where procalcitonin will decrease) and poor outcome (where procalcitonin will not decrease).

Procalcitonin, C-reactive protein, neutrophil gelatinase-associated lipocalin, resistin and the APTT waveform for the early diagnosis of serious bacterial infection and prediction of outcome in critically ill children

OBJECTIVE

Bacterial Infections remains a leading cause of death in the Paediatric Intensive Care Unit (PICU). In this era of rising antimicrobial resistance, new tools are needed to guide antimicrobial use. The aim of this study was to investigate the accuracy of procalcitonin (PCT), neutrophil gelatinase-associated lipocalin (NGAL), resistin, activated partial thromboplastin time (aPTT) waveform and C-reactive protein (CRP) for the diagnosis of serious bacterial infection (SBI) in children on admission to PICU and their use as prognostic indicators.

SETTING

A regional PICU in the United Kingdom.

PATIENTS

Consecutive PICU admissions between October 2010 and June 2012.

MEASUREMENTS

Blood samples were collected daily for biomarker measurement. The primary outcome measure was performance of study biomarkers for diagnosis of SBI on admission to PICU based on clinical, radiological and microbiological criteria. Secondary outcomes included durations of PICU stay and invasive ventilation and 28-day mortality. Patients were followed up to day 28 post-admission.

MAIN RESULTS

A total of 657 patients were included in the study. 92 patients (14%) fulfilled criteria for SBI. 28-day mortality was 2.6% (17/657), but 8.7% (8/92) for patients with SBI. The combination of PCT, resistin, plasma NGAL and CRP resulted in the greatest net reclassification improvement compared to CRP alone (0.69, p<0.005) with 10.5% reduction in correct classification of patients with SBI (p 0.52) but a 78% improvement in correct classification of patients without events (p <0.005). A statistical model of prolonged duration of PICU stay found log-transformed maximum values of biomarkers performed better than first recorded biomarkers. The final model included maximum values of CRP, plasma NGAL, lymphocyte and platelet count (AUC 79%, 95% CI 73.7% to 84.2%). Longitudinal profiles of biomarkers showed PCT levels to decrease most rapidly following admission SBI.

CONCLUSION

Combinations of biomarkers, including PCT, may improve accurate and timely identification of SBI on admission to PICU.

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

The Dynamical Assessment of Inflammatory Biomarkers in Predicting the Outcome of Septic Patients and the Response to Antimicrobial Therapy

Aims

To evaluate the kinetics of inflammatory biomarkers in septic patients in order to identify the most reliable predictor of unfavorable outcome.

Methods

A prospective analysis of septic patients was performed. Median levels of neutrophil/lymphocyte count ratio, fibrinogen, C-reactive protein and procalcitonin were dynamically assessed and comparatively analyzed.

Results

Seventy-seven patients were included. Descendent kinetic patterns were registered for all biomarkers, except C-reactive protein. At 24 hours, neutrophil/lymphocyte count ratio significantly decreased in 42.85% of cases, procalcitonin in 37.33%, C-reactive protein in 16.12% and fibrinogen in 1.58% of cases. At 72 hours, procalcitonin decreased to one-half in 70% of cases and neutrophil/lymphocyte count ratio in 67.53% of cases.

Conclusions

Neutrophil/lymphocyte count ratio and procalcitonin significantly decreased in the first 72 hours, while C-reactive protein increased in the first 24 hours. The proportions of patients with major decrease of baseline values were higher for neutrophil/lymphocyte count ratio and procalcitonin.

Procalcitonin to stop antibiotics after cardiovascular surgery in a pediatric intensive care unit-The PROSACAB study

INTRODUCTION AND OBJECTIVE

Children admitted to the pediatric intensive care unit after cardiovascular surgery usually require treatment with antibiotics due to suspicion of infection. The aim of this study was to assess the effectiveness of procalcitonin in decreasing the duration of antibiotic treatment in children after cardiovascular surgery.

METHODS

Prospective, interventional study carried out in a pediatric intensive care unit. Included patients under 18 years old admitted after cardiopulmonary bypass. Two groups were compared, depending on the implementation of the PCT-guided protocol to stop or de-escalate the antibiotic treatment (Group 1, 2011-2013 and group 2, 2014-2018). This new protocol was based on the decrease of the PCT value by 20% or 50% with respect to the maximum value of PCT. Primary endpoints were mortality, stewardship indication, duration of antibiotic treatment, and antibiotic-free days.

RESULTS

886 patients were recruited. There were 226 suspicions of infection (25.5%), and they were confirmed in 38 cases (16.8%). The global rate of infections was 4.3%. 102 patients received broad-spectrum antibiotic (4.7±1.7 days in group 1, 3.9±1 days in group 2 with p = 0.160). The rate of de-escalation was higher in group 2 (30/62, 48.4%) than in group 1 (24/92, 26.1%) with p = 0.004. A reduction of 1.1 days of antibiotic treatment (group 1, 7.7±2.2 and group 2, 6.7±2.2, with p = 0.005) and 2 more antibiotic free-days free in PICU in group 2 were observed (p = 0.001), without adverse outcomes.

CONCLUSIONS

Procalcitonin-guided protocol for stewardship after cardiac surgery seems to be safe and useful to decrease the antibiotic exposure. This protocol could help to reduce the duration of broad-spectrum antibiotics and the duration of antibiotics in total, without developing complications or adverse effects.

Procalcitonin as an Early Laboratory Marker of Sepsis in Neonates: Variation in Diagnostic Performance and Discrimination Value

Background

As an early recognition of neonatal sepsis is important for triggering the initiation of treatment, this study was thus designed to assess the diagnostic performance and discrimination value of procalcitonin (PCT) in neonatal sepsis cases.

Methods

This cross-sectional study, which was carried out at the Paediatric Intensive Care Unit of Hospital Universiti Sains Malaysia (HUSM) in Kelantan, Malaysia, had involved 60 neonates admitted for suspected sepsis. Sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV) and the area under receiver operating characteristics curve (AUC) for PCT were determined at initial presentation (0 h) as well as 12 h and 24 h after presentation in comparison to blood culture as the gold standard.

Results

The study consisted of 27 (45.0%) male and 33 (55.0%) female neonates with a mean (SD) age of 76.8 (48.25) h. At cut-off PCT value of > 2 ng/mL, the sensitivity, specificity, PPV and NPV were 66.7%, 66.7%, 33.3% and 88.9% at 0 h. The respective parameters were 83.3%. 56.3%, 32.3% and 93.1% at 12 h and 83.3%, 52.1%, 30.3% and 92.6% at 24 h. AUC was 71.6%, 76.6% and 71.7% at 0 h, 12 h and 24 h.

Conclusions

Diagnostic performance and discrimination values of PCT for diagnosis of neonatal sepsis varied with time of obtaining the blood samples. The PCT result at 12 h demonstrates the most optimal diagnostic performance and discrimination values.

Procalcitonin Concentration Measured Within the First Days of Cardiac Surgery Is Predictive of Postoperative Infections in Neonates: A Case-Control Study

Increased procalcitonin concentration (PCT) is known to be reliable for the identification of infections even in the presence of the non-specific systemic inflammatory response seen after cardiopulmonary bypass (CPB), whereas increased C-reactive protein concentration (CRP) is not. The present work explored the ability of neonate PCT measured early after cardiac surgery to identify postoperative infections. This was a retrospective case-control study, where PCT was matched between patients with and without infections according to the patient's age, the CPB length, the use of deep hypothermic circulatory arrest (DHCA), and the postoperative day (POD). The accuracy in the prediction of infections was ascertained and cutoff thresholds were identified. 144 neonates were eligible, and 89 pairs of measurements from 94 patients were analyzed. PCT was a good predictor of infections within POD4, and was a better predictor when compared with CRP at POD1 and POD2. The sum of PCT (pg mL^-1) and CRP (mg L^-1) > 33 on POD1 or POD2 predicted infections with a 0.68 sensitivity and a 0.82 specificity, and a sum  > 49.36 on POD3 or POD4 predicted infections with a 0.82 sensitivity and a 0.93 specificity. In patients with DHCA, PCT was higher than in those without DHCA, and was not predictive of infections. The accuracy of PCT to identify infections after neonatal cardiac surgery is better than that of CRP when measured within 48 h of surgery. The sum of the two markers measured early after surgery is an excellent predictor of postoperative infections.

Prognostic value of biomarkers after cardiopulmonary bypass in pediatrics: The prospective PANCAP study

Objective

To assess the usefulness of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide as predictors of need for mechanical ventilation and postoperative complications (need for inotropic support and bacterial infection) in critically ill pediatric patients after cardiopulmonary bypass.

Design

A prospective, observational study

Setting

Pediatric intensive care unit.

Patients

Patients under 18 years old admitted after cardiopulmonary bypass.

Measuraments and main results

Serum levels of procalcitonin, pro-adrenomedullin and pro-atrial natriuretic peptide were determined immediately after bypass and at 24–36 hours. Their values were correlated with the need for mechanical ventilation, inotropic support and bacterial infection. One hundred eleven patients were recruited. Septal defects (30.6%) and cardiac valve disease (17.1%) were the most frequent pathologies. 40.7% required mechanical ventilation, 94.6% inotropic support and 15.3% presented invasive bacterial infections. Pro-adrenomedullin and pro-atrial natriuretic peptide showed significant high values in patients needing mechanical ventilation. Cut-off values higher than 1.22 nmol/L and 215.3 pmol/L, respectively for each biomarker, may indicate need for mechanical ventilation with an AUC of 0.721 and 0.746 at admission and 0.738 and 0.753 at 24–36 hours, respectively but without statistical differences. Pro-adrenomedullin and procalcitonin showed statistically significant high values in patients with bacterial infections.

Conclusions

After bypass, pro-adrenomedullin and pro-atrial natriuretic peptide are suitable biomarkers to predict the need for mechanical ventilation. Physicians should be alert if the values of these markers are high so as not to progress to early extubation. Procalcitonin is useful for predicting bacterial infection. This is a preliminary study and more clinical studies should be done to confirm the value of pro-adrenomedullin and pro-atrial natriuretic peptide as biomarkers after cardiopulmonary bypass.

Is Procalcitonin Useful in Pediatric Critical Care Patients?

This review examines the use of procalcitonin in different clinical situations in the pediatric patient, with special emphasis on those requiring intensive care. We review the latest articles on its potency as a biomarker in both infectious processes at diagnosis and on the response to treatment.

Undue Elevation of Procalcitonin in Pediatric Paracetamol Intoxication is Not Explained by Liver Cell Injury Alone

INTRODUCTION AND AIM

Procalcitonin is widely used as a biomarker to distinguish bacterial infections from other etiologies of systemic inflammation. Little is known about its value in acute liver injury resulting from intoxication with paracetamol.

MATERIAL AND METHODS

We performed a single-center retrospective analysis of the procalcitonin level, liver synthesis, liver cell damage and renal function of patients admitted with paracetamol-induced liver injury to a tertiary care children's hospital. Children with acute liver failure due to other reasons without a bacterial or fungal infection served as the control group. Twelve patients with acute paracetamol intoxication and acute liver injury were compared with 29 patients with acute liver failure.

RESULTS

The procalcitonin levels were higher in children with paracetamol intoxication than in patients with acute liver failure without paracetamol intoxication (median 24.8 (0.01-55.57) ng/mL vs. 1.36 (0.1-44.18) ng/mL; p &lt; 0.005), although their liver and kidney functions were better and the liver cell injury was similar in both groups. Outcome analysis showed a trend towards better survival without transplantation in patients with paracetamol intoxication (10/12 vs. 15/29). Within each group, procalcitonin was significantly correlated with alanine aminotransferase and aspartate aminotransferase but was not correlated with the International Normalized Ratio or paracetamol blood levels in the paracetamol group. In conclusion, paracetamol intoxication leads to a marked increase in procalcitonin serum levels, which are significantly higher than those seen in acute liver failure.

CONCLUSION

The underlying mechanism is neither caused by infection nor fully explained by liver cell death alone and remains to be determined.

Kinetics of Procalcitonin in Pediatric Patients on Extracorporeal Membrane Oxygenation

Objectives:

To assess the kinetics of procalcitonin (PCT) and C-reactive protein (CRP) in pediatric patients who required extracorporeal membrane oxygenation (ECMO) and to analyze its relationship with morbidity and mortality.

Patients and methods:

Prospective observational study including pediatric patients who required ECMO. Both PCT and CRP were sequentially drawn before ECMO (P0) and until 72 hours after ECMO.

Results:

A total of 40 patients were recruited. Two cohorts were established based on the value of the P0 PCT (>10 ng/mL). Comparing the kinetics of PCT and CRP in these cohorts, the described curves were the expected for each clinical situation. The cutoff for P0 PCT to predict multiple organ dysfunction syndrome was 2.55 ng/mL (sensibility 83%, specificity 100%). Both PCT and CRP did not predict risk of neurologic sequelae or mortality in any group.

Conclusions:

Procalcitonin does not seem to be modified by ECMO and could be a good biomarker of evolution.

Double-Edged Sword: Musculoskeletal Infection Provoked Acute Phase Response in Children

The acute phase response has a crucial role in mounting the body's response to tissue injury. Excessive activation of the acute phase response is responsible for many complications that occur in orthopedic patients. Given that infection may be considered continuous tissue injury that persistently activates the acute phase response, children with musculoskeletal infections are at markedly increased risk for serious complications. Future strategies that modulate the acute phase response have the potential to improve treatment and prevent complications associated with musculoskeletal infection.

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.

Hybrid minimally invasive esophagectomy for cancer: impact on postoperative inflammatory and nutritional status

The purpose of this case-control study was to evaluate the impact of hybrid minimally invasive esophagectomy for cancer on surgical stress response and nutritional status. All 34 consecutive patients undergoing hybrid minimally invasive esophagectomy for cancer at our surgical unit between 2008 and 2013 were retrospectively compared with 34 patients undergoing esophagectomy with open gastric tubulization (open), matched for neoadjuvant therapy, pathological stage, gender and age. Demographic data, tumor features and postoperative course (including quality of life and systemic inflammatory and nutritional status) were compared. Postoperative course was similar in terms of complication rate. Length of stay in intensive care unit was shorter in patients undergoing hybrid minimally invasive esophagectomy (P = 0.002). In the first postoperative day, patients undergoing hybrid minimally invasive esophagectomy had lower C-reactive protein levels (P = 0.001) and white cell blood count (P = 0.05), and higher albumin serum level (P = 0.001). In this group, albumin remained higher also at third (P = 0.06) and seventh (P = 0.008) postoperative day, and C-reactive protein resulted lower at third post day (P = 0.04). Hybrid minimally invasive esophagectomy significantly improved the systemic inflammatory and catabolic response to surgical trauma, contributing to a shorter length of stay in intensive care unit.

Reduction in procalcitonin level and outcome in critically ill children with severe sepsis/septic shock-A pilot study

PURPOSE

To investigate if reduction in procalcitonin (PCT) provides useful information about 28-day mortality in children with severe sepsis or septic shock.

MATERIALS AND METHODS

Design: Prospective observational study.

SETTING

Mixed adult-pediatric intensive care unit in a teaching hospital.

SUBJECTS

Children up to 18 years of age admitted with severe sepsis or septic shock between March 2011 and June 2013. Procalcitonin measured using electrochemiluminescence immunoassay on the day of admission with sepsis (D0) and 72-96 hours later (D4). Reduction in PCT from D0 to D4 correlated with the primary outcome, that is, 28-day mortality.

RESULTS

Twenty-five children of median age of 14 years (range, 6-18 years) were included, but 5 died before D4 after admission. Six of the remaining 20 children died between D4 and D28, and 14 survived to D28. At admission, the median of the Pediatric Risk of Mortality III score was 10 (interquartile range [IQR], 5-16) and that of the Sequential Organ Failure Assessment score was 11 (IQR, 7-15). The median PCT level was 9.7 ng/mL on D0 (n = 25) and 3.3 ng/mL on D4 (n = 20). On D0, the median PCT level was 25.0 ng/mL in the 14 survivors and 8.4 ng/mL in the 11 nonsurvivors (P = .075). On D4, the median PCT level was 3.1 ng/mL in the 14 survivors and 4.5 ng/mL in the 6 nonsurvivors who lived to D4 (P = .71); the reduction in PCT (D0 minus D4) was 17.3 ng/mL (IQR, 3.5-38.0 ng/mL) in the survivors and -1.1 ng/mL (IQR, -24.9 to 8.6 ng/mL) in the 6 nonsurvivors (P = .017). Percent reduction in PCT (100 * [D0 - D4]/D0) was 75.5% (IQR, 54.8%-80.7%) in the survivors and -200.3% (IQR, -937.8% to 42.4%) in the 6 nonsurvivors (P = .006).

CONCLUSION

This small pilot study suggests that further studies are indicated to determine whether children with severe sepsis or septic shock are less likely to die if they have a reduction in PCT more than 50% in the first 4 days in intensive care.

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.

Elimination Half-Lives of Acute Phase Proteins in Rats and Beagle Dogs During Acute Inflammation

The half-lives of typical acute phase proteins in rats and beagle dogs during acute inflammation were investigated. Acute inflammation was induced by injection of turpentine oil in rats and administration of indomethacin in beagle dogs. Serum concentrations of α2-macroglobulin (α2M) and C-reactive protein (CRP) were measured by enzyme-linked immunosorbent assay and α1-acid glycoprotein (AAG) was measured by single radial immunodiffusion. Half-life was calculated as 0.693/elimination rate constant (K). The mean half-lives in the terminal elimination phase of α2M and AAG were 68.1 and 164.8 h, respectively. The half-life of AAG was significantly longer than that of α2M. Mean half-lives in the terminal elimination phase of CRP and AAG were 161.9 and 304.4 h, respectively. The half-life of AAG was significantly longer than that of CRP in beagle dogs. No significant differences in the half-life of AAG were observed between rats and beagle dogs. Furthermore, serum concentrations in the terminal elimination phase could be simulated with the K data acquired in this study.

Procalcitonin to Detect Suspected Bacterial Infections in the PICU

OBJECTIVES

Nonspecific clinical symptoms frequently lead to suspicion of bacterial infection in critically ill children. Clinicians send bacterial cultures for suspected infection and begin an empiric course of antibiotics while microbiology results are pending. We investigated whether the biomarker procalcitonin could be useful to predict confirmed bacterial infection in critically ill children in the PICU, before culture results are available.

DESIGN

Prospective, blinded single-center study.

SETTING

Tertiary PICU and cardiothoracic ICU.

PATIENTS

There were one hundred forty-four patients with suspected bacterial infections that had bacterial cultures sent by clinicians.

INTERVENTIONS

Procalcitonin samples were obtained at three time intervals: as close to the time of the initial culture as possible (up to 12 hr after) and 24 and 72 hours after the initial culture. Patients were stratified into clinical outcome groups based on microbiology results and clinical symptoms using Centers for Disease Control and Prevention criteria. These assignments were blinded to procalcitonin levels. Primary outcome was the presence of culture-proven bacterial infection.

MEASUREMENTS AND MAIN RESULTS

There was a statistically significant difference in initial and subsequent median procalcitonin values between patients with confirmed bacterial infections and patients with low suspicion of bacterial infection (p < 0.02). However, there was extremely high variability in procalcitonin values among all groups. Procalcitonin had only a fair ability to predict bacterial infection, with area under the curve of receiver operating characteristic plots ranging between 0.63 and 0.71. When using serial procalcitonin values to predict bacterial infection, positive likelihood ratios were near 1 and negative likelihood ratios were between 0.3 and 0.4.

CONCLUSIONS

Procalcitonin levels were higher in children with documented confirmed bacterial infection as compared with those with low suspicion of infection. However, neither single nor serial procalcitonin measurements were able to predict the presence or absence of confirmed bacterial infection with enough certainty to be clinically useful as to recommend initiating or withholding antibiotics.

Pretreatment with an intravenous lipid emulsion increases plasma eicosapentanoic acid and downregulates leukotriene b4, procalcitonin, and lymphocyte concentrations after open heart surgery in infants

BACKGROUND

The effect of providing a lipid emulsion containing medium-chain triglyceride (MCT), soybean oil, and fish oil in critically ill infants is not widely studied. This study investigated lipid emulsion effects on plasma phospholipids and immune biomarkers.

MATERIALS AND METHODS

Thirty-two infants undergoing cardiopulmonary bypass (CPB) and dependent on parenteral nutrition (PN) were randomized to receive either soybean oil (control, n = 16) or a 50:40:10 mixture of MCT, soybean oil, and fish oil (treatment, n = 16). PN was administered for 3 days preoperatively and 10 days postoperatively. Fatty acids, procalcitonin (PCT), leukotriene B4 (LTB4), and lymphocytes were quantified at baseline, before surgery, and days 1, 7 and 10 after surgery.

RESULTS

PCT was significantly lower in the treatment vs control group 1 day postoperatively (P = .01). The treatment group exhibited a lower ω-6 to ω-3 ratio (P = .0001) and a higher ω-3 concentration at all postoperative study periods (P = .001). Treatment resulted in higher (P < .05) plasma phospholipid eicosapentaenoic acid (EPA) on days 7 and 10, while α-linolenic acid, arachidonic acid, and docosahexaenoic acid remained constant. An increase in plasma phospholipid EPA concentration was associated with a decrease in plasma phospholipid LTB4 concentration (P < .05). On postoperative day 10, treatment infants with high Pediatric Risk of Mortality III scores exhibited a 45% lower lymphocyte concentration (P < .05).

CONCLUSION

These findings suggest that treating infants undergoing CPB with a lipid emulsion containing ω-3 improves fatty acid status and results in a lower inflammatory response after surgery. Overall, this alternative ω-3-enriched lipid emulsion may benefit clinical outcomes of critically ill infants after cardiac surgery.