Age-specific percentile-based reference curve of serum procalcitonin concentrations in Japanese preterm infants

Can We Estimate Late-Onset Sepsis by Serial Methemoglobin Levels? An Observational Study in Preterm Neonates

Objective: To assess serial methemoglobin (MetHb) levels in preterm infants as a possible diagnostic method for late-onset sepsis (LOS). Methods: Preterm infants were assigned into two groups: those with culture-proven LOS and controls. Serial MetHb levels were measured. Results: The MetHb values of the LOS group were found to be significantly increased (p < 0.001). The cutoff value for the detection of LOS was calculated as MetHb > 1.75%, optimized for a sensitivity of 81.9% and specificity of 90%. After antimicrobial therapy, MetHb values were found to decrease significantly (p < 0.001). MetHb had an AUC of 0.810 for mortality using the calculated cutoff of >2% (p < 0.005). Conclusions: MetHb levels increase at the onset of LOS and decrease following treatment. MetHb can be added to other sepsis biomarkers as a rapid infectious process indicator for preterm neonates. MetHb > 2% is associated with LOS mortality.

Procalcitonin-Based Antibiotic Use for Neonatal Early-Onset Bacterial Infections: Pre- and Post-Intervention Clinical Study

We previously reported the 95th percentile cutoff value of the serum procalcitonin (PCT) reference curve for diagnosing early-onset bacterial infection. We aimed to verify the effectivity of these novel diagnostic criteria by comparing antibiotic use and incidence of early-onset bacterial infection between pre- and post-introduction periods. We included newborns admitted to our neonatal intensive care unit who underwent blood tests within 72 h after birth between 2018 and 2022. The neonates were divided into the pre-intervention (admitted before the introduction, n = 737) or post-intervention (admitted after the introduction, n = 686) group. The days of antibiotics therapy (DOT) per 1000 patient days up to 6 days after birth, percentage of antibiotic use, and incidence of early-onset bacterial infection were compared between the groups. The post-intervention group had significantly lower DOT per 1000 patient days (82.0 days vs. 211.3 days, p < 0.01) and percentage of newborns receiving antibiotics compared with the pre-intervention group (79 (12%) vs. 280 (38%), respectively, p < 0.01). The incidence of early-onset bacterial infections did not differ between the groups (2% each, p = 0.99). In conclusion, our diagnostic criteria using the 95th percentile cutoff value of the serum PCT reference curve for early-onset bacterial infection were proven safe and effective, promoting appropriate use of antibiotics.

Role of Procalcitonin as a Biomarker in Early Identification of Adverse Events Following Esophageal Atresia Surgery

Introduction

Surgical complication following esophageal atresia repair is one of the several factors known to influence the final outcomes. Early identification of such complications may help in timely institution of therapeutic measures and translate into improved prognosis.

Objective

The objective of this study was to evaluate the role of procalcitonin in early prediction of the adverse events after surgery in patients of esophageal atresia and the temporal relationship with clinical manifestations and other inflammatory biomarkers such as C-reactive protein (CRP).

Materials and Methods

This was a prospective study on consecutive patients of esophageal atresia (n = 23). Serum procalcitonin and CRP levels were assessed at baseline (prior to surgery) and on postoperative days (POD) 1, 3, 5, 7, and 14. The trends in the biomarker values and temporal relationships of deviation in trend with the clinical and conventional laboratory parameters and patient outcomes were analyzed.

Results

Baseline serum procalcitonin was elevated (n = 23; 1.7 ng/ml: min: 0.07 ng/ml-max: 24.36 ng/ml) in 18/23 (78.3%) patients. Procalcitonin nearly doubled on POD-1 (n = 22; 3.28 ng/ml: min: 0.64 ng/ml-max: 16.51 ng/ml) followed by a gradual decline. CRP was also elevated on POD-1 (three times the baseline) and depicted a delayed peak at POD-3. POD-1 procalcitonin and CRP levels correlated with survival. POD-1 procalcitonin cutoff at 3.28 ng/ml predicted mortality with a sensitivity and specificity of 100% and 57.9% (P = 0.05). Serum procalcitonin and CRP were higher for patients who sustained complications, so was the time required for hemodynamic stabilization. Procalcitonin (baseline and POD-5) and CRP (POD-3 and POD-5) values correlated with the clinical course after surgery. Baseline procalcitonin cutoff at 2.91 ng/ml predicted the possibility of a major complication with a sensitivity of 71.4% and a specificity of 93.3%. POD-5 procalcitonin cutoff at 1.38 ng/ml predicted the possibility of a major complication with a sensitivity of 83.3% and a specificity of 93.3%. Patients who sustained major complications depicted a change in serum procalcitonin trend 24-48 h ahead of clinical manifestation of an adverse event.

Conclusions

Procalcitonin is a good indicator to identify the adverse events in neonates after surgery for esophageal atresia. The procalcitonin levels in patients who sustained a major complication depicted a reversal in trend 24-48 h of clinical manifestation. POD-1 procalcitonin correlated with survival while the baseline and POD-5 serum procalcitonin predicted the clinical course.

The evolving value of older biomarkers in the clinical diagnosis of pediatric sepsis

Sepsis remains the leading cause of childhood mortality worldwide. The evolving definition of pediatric sepsis is extrapolated from adult studies. Although lacking formal validation in the pediatric population, this working definition has historically proven its clinical utility. Prompt identification of pediatric sepsis is challenging as clinical picture is often variable. Timely intervention is crucial for optimal outcome, thus biomarkers are utilized to aid in immediate, yet judicious, diagnosis of sepsis. Over time, their use in sepsis has expanded with discovery of newer biomarkers that include genomic bio-signatures. Despite recent scientific advances, there is no biomarker that can accurately diagnose sepsis. Furthermore, older biomarkers are readily available in most institutions while newer biomarkers are not. Hence, the latter's clinical value in pediatric sepsis remains theoretical. Albeit promising, scarce data on newer biomarkers have been extracted from research settings making their clinical value unclear. As interest in newer biomarkers continue to proliferate despite their ambiguous clinical use, the literature on older biomarkers in clinical settings continue to diminish. Thus, revisiting the evolving value of these earliest biomarkers in optimizing pediatric sepsis diagnosis is warranted. This review focuses on the four most readily available biomarkers to bedside clinicians in diagnosing pediatric sepsis. IMPACT: The definition of pediatric sepsis remains an extrapolation from adult studies. Older biomarkers that include C-reactive protein, procalcitonin, ferritin, and lactate are the most readily available biomarkers in most pediatric institutions to aid in the diagnosis of pediatric sepsis. Older biomarkers, although in varying levels of reliability, remain to be useful clinical adjuncts in the diagnosis of pediatric sepsis if used in the appropriate clinical context. C-reactive protein and procalcitonin are more sensitive and specific among these older biomarkers in diagnosing pediatric sepsis although evidence varies in different age groups and clinical scenarios.

Predictive Value of Ionized Calcium for Prognosis of Sepsis in Very Low Birth Weight Infants

Purpose

Previous studies have shown that ionized calcium (iCa) is strongly correlated with critical illnesses, including sepsis. However, there are few studies on the association of iCa levels and sepsis in very low birth weight infants (VLBWI). Therefore, the aim of this study was to investigate the role of iCa in assessing the severity of sepsis and in predicting the prognosis of sepsis in VLBWI.

Patients and Methods

249 eligible VLBWI with sepsis were included in the present study and were divided into good and poor prognosis groups according to prognosis. We collected complete laboratory and clinical data. The lowest iCa measured during the first 24h from sepsis onset was recorded, and the Pediatric Risk of Mortality (PRISM III) score was calculated for each newborn.

Results

Neonatal mortality was higher in the hypocalcemia group (32.80% vs 12.80%, P < 0.001), and iCa levels were negatively correlated with PRISM III scores (r= −0.819, P < 0.001). The result of multiple logistic regression analysis showed that iCa was an independent predictor of poor prognosis (odds ratio [OR]= 0.558, 95% confidence interval [CI], 0.406–0.768, P < 0.001). Furthermore, our data demonstrated that iCa was also an independent predictor for the occurrence of death in VLBWI with sepsis who have a poor prognosis (OR= 0.659, 95% CI, 0.445–0.977, P =0.038). ROC curve analysis showed that iCa had good discriminatory power in predicting the poor prognosis (AUC=0.739, 95% CI, 0.664–0.813, P <0.001) in VLBWI with sepsis.

Conclusion

iCa levels correlate with the severity of sepsis and can be an independent predictor of poor prognosis in VLBWI with sepsis.

Introducing heart rate variability monitoring combined with biomarker screening into a level IV NICU: a prospective implementation study

The aim of this study was to investigate the association between the implementation of a local heart rate variability (HRV) monitoring guideline combined with determination of inflammatory biomarkers and mortality, measures of sepsis severity, frequency of sepsis testing, and antibiotic usage, among very preterm neonates. In January 2018, a guideline was implemented for early detection of late-onset neonatal sepsis using HRV monitoring combined with determination of inflammatory biomarkers. Data on all patients admitted with a gestational age at birth of < 32 weeks were reviewed in the period January 2016-June 2020 (n = 1,135; n = 515 pre-implementation, n = 620 post-implementation). Outcomes of interest were (sepsis-related) mortality, sepsis severity (neonatal sequential organ failure assessment (nSOFA)), sepsis testing, and antibiotic usage. Differences before and after implementation of the guideline were assessed using logistic and linear regression analysis for binary and continuous outcomes respectively. All analyses were adjusted for gestational age and sex. Mortality within 10 days of a sepsis episode occurred in 39 (10.3%) and 34 (7.6%) episodes in the pre- and post-implementation period respectively (P = 0.13). The nSOFA course during a sepsis episode was significantly lower in the post-implementation group (P = 0.01). We observed significantly more blood tests for determination of inflammatory biomarkers, but no statistically significant difference in number of blood cultures drawn and in antibiotic usage between the two periods.Conclusion: Implementing HRV monitoring with determination of inflammatory biomarkers might help identify patients with sepsis sooner, resulting in reduced sepsis severity, without an increased use of antibiotics or number of blood cultures.

Procalcitonin levels in preterm newborns: Reference ranges during the first three days of life

BACKGROUND

Sepsis is one of the most important causes of morbidity and mortality in the neonatal period, especially in preterms. Diagnosis is difficult because of specific signs and symptoms. The diagnostic gold standard is blood culture, but its sensibility is low. Much effort has been made to identify early, sensitive, and specific diagnostic markers; among these markers particular attention was paid to procalcitonin. However, reference ranges of serum procalcitonin (PCT) shortly after birth have not been sufficiently studied in healthy preterms, and literature is still contradictory.

OBJECTIVES

The aim of the study is to define PCT age-specific reference ranges in the first 72 h of life in uninfected VLBW preterms.

METHODS

Serum levels of PCT were assessed for each newborn at birth and every 24 h until the 3rd day of life. The eligible patients were classified into two groups according to their sepsis status.

RESULTS

Approximately 343 patients were enrolled; 28 were septic and 315 non-septic. In non-septic infants, 1,015 determinations of PCT values were performed. Our data showed a trend in average value of PCT to increase after birth up to a peak between 24 and 48 h of life and, subsequently, to fall. The average peak value was 15.12 ng/ml achieved at nearly 36 h of life.

CONCLUSION

Our study shows a PCT nomogram of healthy preterms, which is different from the one of term newborns. Data agree with what is reported in literature on the reference ranges and trends of PCT in non-septic preterms shortly after birth.

Early-onset sepsis risk calculator: a review of its effectiveness and comparative study with our evidence-based local guidelines

Background

According to most early-onset sepsis (EOS) management guidelines, approximately 10% of the total neonatal population are exposed to antibiotics in the first postnatal days with subsequent increase of neonatal and pediatric comorbidities. A review of literature demonstrates the effectiveness of EOS calculator in reducing antibiotic overtreatment and NICU admission among neonates ≥34 weeks’ gestational age (GA); however, some missed cases of culture-positive EOS have also been described.

Methods

Single-center retrospective study from 1st January 2018 to 31st December 2018 conducted in the Division of Neonatology at Santa Chiara Hospital (Pisa, Italy). Neonates ≥34 weeks’ GA with birth weight ≤ 1500 g, 34–36 weeks’ GA neonates with suspected intraamniotic infection and neonates ≥34 weeks’ GA with three clinical signs of EOS or two signs and one risk factor for EOS receive empirical antibiotics. Neonates ≥34 weeks’ GA with risk factors for EOS or with one clinical indicator of EOS undergo serial measurements of C-reactive protein and procalcitonin in the first 48–72 h of life; they receive empirical antibiotics in case of abnormalities at blood exams with one or more clinical signs of EOS. Two hundred sixty-five patients at risk for EOS met inclusion criteria; they were divided into 3 study groups: 34–36 weeks’ GA newborns (n = 95, group A), ≥ 37 weeks’ GA newborns (n = 170, group B), and ≥ 34 weeks’ GA newborns (n = 265, group A + B). For each group, we compared the number of patients for which antibiotics would have been needed, based on EOS calculator, and the number of the same patients we treated with antibiotics during the study period. Comparisons between the groups were performed using McNemar’s test and statistical significance was set at p < 0.05; post-hoc power analysis was carried out to evaluate the sample sizes.

Results

32/265 (12.1%) neonates ≥34 weeks’ GA received antibiotics within the first 12 h of life. According to EOS calculator 55/265 (20.7%) patients would have received antibiotics with EOS incidence 2/1000 live births (p < 0.0001).

Conclusion

Our evidence-based protocol entails a further decrease of antibiotic overtreatment compared to EOS calculator. No negative consequences for patients were observed.

Expression of Pancreatic Stone Protein is Unaffected by Trauma and Subsequent Surgery in Burn Patients

BACKGROUND

Altered levels of pro-inflammatory markers secondary to trauma or surgery present a major problem to physicians in being prone to interfere with the clinical identification of infectious events.

METHODS

Patients admitted to Zurich Burn Center between May 2015 and October 2018 with burns ≥10% total body surface area (TBSA) and without infection. Longitudinal analysis of the time course of PSP and routine inflammatory biomarkers [procalcitonin (PCT), C-reactive protein (CRP) and white blood cells (WBC)] over two days after (a) trauma with initial debridement and (b) subsequent burn surgeries was performed. The influence of TBSA, abbreviated burn severity index (ABSI), age and length of operation was investigated using a linear mixed effect regression model.

RESULTS

Sixty-six patients (15 female) were included with a mean age of 45.5 ± 18.3 years, median TBSA of 22% (IQR 17) and mean ABSI score 6.8 ± 2.7. PSP was the only biomarker that showed no association with any of the baseline characteristics. Additionally, PSP serum levels did not change over time neither after the burn trauma (p = 0.832) nor after secondary procedures (p = 0.113), while PCT levels increased significantly after the trauma (p < 0.001). Similarly, CRP serum levels were elevated significantly after both trauma and surgery (p < 0.001), whereas WBC values demonstrated a significant decline after the trauma (p < 0.001).

CONCLUSION

Established biomarkers (WBC, CRP and PCT) demonstrate decisive alterations after tissue destruction caused by burn injuries and subsequent surgical interventions. The robustness of PSP serum levels toward these inflammatory insults is a quality criterion for an upcoming sepsis biomarker.

Procalcitonin in Preterm Neonates: A Different Threshold and Prolonged Interpretation

Objectives: To evaluate the positive threshold of PCT for neonates of <32 weeks of gestation for the diagnosis of early-onset sepsis and to determine if the level of PCT collected within 6 h of life could be used. Design: Retrospective and bicentric study from May 2016 to April 2018. Setting: Two groups were established, neonates evaluated for PCT at birth (CordPCT) and within 6 h of life (delPCT). Patients: Two hundred and sixty neonates of <32 weeks of gestation born in Nice and South Paris (Bicêtre) University Hospitals, had been evaluated for PCT level. Main Outcomes Measures: The value of the PCT positive threshold was determined for the total population and each groups thanks ROC curves. Results: The threshold level of PCT for the total population was 0.98 ng/mL. The threshold value of cordPCT group was 1.00 vs. 0.98 ng/mL for delPCT group. The area under the Receiver Operating Characteristics curve for PCT sampled in delPCT group was significantly higher than in cordPCT group (0.94 compared to 0.75). Conclusions: The threshold level of PCT was higher in this cohort of neonates of <32 weeks of gestation compared to the value generally described for term neonates. The secondary sampling PCT level seems to be usable in screening algorithm for early-onset neonatal sepsis.

Relevance of Biomarkers Currently in Use or Research for Practical Diagnosis Approach of Neonatal Early-Onset Sepsis

Neonatal early-onset sepsis (EOS) is defined as an invasive infection that occurs in the first 72 h of life. The incidence of EOS varies from 0.5–2% live births in developed countries, up to 9.8% live births in low resource settings, generating a high mortality rate, especially in extremely low birth weight neonates. Clinical signs are nonspecific, leading to a late diagnosis and high mortality. Currently, there are several markers used for sepsis evaluation, such as hematological indices, acute phase reactants, cytokines, which by themselves do not show acceptable sensitivity and specificity for the diagnosis of EOS in neonates. Newer and more selective markers have surfaced recently, such as presepsin and endocan, but they are currently only in the experimental research stages. This comprehensive review article is based on the role of biomarkers currently in use or in the research phase from a basic, translational, and clinical viewpoint that helps us to improve the quality of neonatal early-onset sepsis diagnosis and management.

Diagnostic Accuracy of Biomarkers for Early-Onset Neonatal Bacterial Infections: Evaluation of Serum Procalcitonin Reference Curves

To date, no clinical studies have compared the accuracy of serum procalcitonin (PCT) reference curves. We aimed to validate the diagnostic accuracy of previously reported serum PCT reference curves and to determine which biomarkers among a cut-off value over the 95th percentile in the serum PCT reference curve, white blood cell (WBC) count, and C-reactive protein (CRP) and immunoglobulin M (IgM) levels, have the highest diagnostic accuracy for early-onset neonatal bacterial infections. This retrospective cohort study assessed 16 preterm and 23 term infants with suspected bacterial infections within 72 h after birth. Each infant group was divided into two subgroups: confirmed- and non-infection. The diagnostic accuracy was determined using the Youden index. The reference curves by Fukuzumi et al. in preterm and term infants had the highest Youden indexes: 1.000 and 0.324, respectively. Among preterm infants, the Youden index for PCT was 1.000. Among term infants, the Youden index for a combination of PCT, CRP, and WBC and/or IgM was 1.000. In conclusion, a serum PCT level over the 95th percentile on the reference curve for preterm infants and a combination of PCT and CRP levels with WBC count and/or IgM levels for term infants provided sufficient diagnostic accuracy.

New reference ranges of procalcitonin excluding respiratory failure in neonates

BACKGROUND

Existing reference data on serum procalcitonin (PCT) in neonates include the effects of respiratory disorders commonly occurring during birth. We aimed to determine new 95% reference intervals in neonates after excluding the influence of respiratory failure at birth, and to investigate the effects of gestational age (GA) and respiratory condition at birth on postnatal transient serum PCT elevation.

METHODS

Samples were obtained from term and preterm neonates during the first 3 days of life. Neonates were classified into reference, respiratory failure, and bacterial infection groups. In the reference group, the correlation between PCT level and GA was investigated.

RESULTS

The median PCT level within the 95% range 12-36 h after birth was 1.05 ng/mL (0.14-4.39) in term neonates (143 samples) and 1.01 ng/mL (0.15-4.44) in preterm neonates (95 samples). There was no correlation between GA and serum PCT level during 1-48 h after birth. There was a significant difference in median serum PCT level during 12-36 h after birth between the respiratory failure (9.56 ng/mL) and bacterial infection (49.82 ng/mL) groups in preterm neonates but no difference between term neonates (respiratory failure 6.83 ng/mL, and bacterial infection 7.43 ng/mL).

CONCLUSIONS

Respiratory failure is the main effector for the transient elevation in serum PCT levels at 3 days of life. After excluding the influence of respiratory failure, the chronological pattern and range were very similar between term and preterm neonates. Procalcitonin can be useful for clinicians in distinguishing bacterial infection from respiratory failure, aiding decisions on appropriate antibiotic use.

Perinatal outcomes of singletons following vitrification versus slow-freezing of embryos: a multicenter cohort study using propensity score analysis

STUDY QUESTION

Is embryo vitrification associated with a higher risk of adverse perinatal outcomes than slow-freezing?

SUMMARY ANSWER

Embryo vitrification was not associated with increased risks of adverse perinatal outcomes of pre-term birth (PTB), low birthweight (LBW), small for gestational age (SGA), large for gestational age (LGA) and macrosomia, as compared to slow-freezing.

WHAT IS KNOWN ALREADY

Vitrification is becoming a widely adopted technology for embryo cryopreservation with higher embryo survival rate and live birth rate than the slow-freezing technique. However, limited data are currently available on risks of adverse perinatal outcomes following vitrification as compared to that of slow-freezing. The impact of vitrification on perinatal outcomes remains further to be elucidated.

STUDY DESIGN, SIZE, DURATION

Six large reproductive medical centers in Guangdong province, Southeast of China, took part in this multicenter retrospective cohort study. Cohorts of 3199 live born singletons after Day 3 frozen-thawed embryo transfer (FET) cycles with either vitrification or slow-freezing between January 2011 and December 2015 were included in the study. Each patient only contributed one cycle per cohort and vanishing twins were excluded. Propensity score (PS) matching was used to control for potential confounding factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All live-born singletons following either a vitrified or a slow-frozen cleavage FET cycle during the period from 2011 to 2015 were analyzed. Perinatal outcomes of PTB, LBW, macrosomia, SGA and LGA were compared. The vitrified and slow-frozen cohorts were matched by propensity scores with a 1:1 ratio accounting for potential confounding factors associated with perinatal outcomes. These variables included baseline demographics (maternal age, BMI, education level, parity, type of infertility and cause of infertility), as well as IVF characteristics (insemination method, endometrial preparation protocol and embryo cryopreservation duration).

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 2858 cases from vitrified embryo transfer (ET) and 341 babies from the slow-freezing group were included. After PS matching, 297 pairs of newborns were generated for comparison. The median gestational age was 39 weeks for both cohorts and the birthweights were comparable (3187.7 ± 502.1 g in the vitrified group vs. 3224.6 ± 483.6 in the slow-freezing group, P>0.05). There were no significant differences between the two groups on the incidence of PTB (5.4% vs. 7.7%), LBW (6.7% vs. 5.7%), macrosomia (5.7% vs. 6.1%), SGA (12.5% vs. 8.4%) and LGA (6.4% vs. 8.1%). Parallel logistic regression analysis indicated that vitrification was non-inferior to slow-freezing method in terms of the occurrence of PTB (OR, 0.68 [95% CI, 0.35, 1.31]), LBW (OR, 1.19[0.61-2.32]), macrosomia (OR, 0.94 [0.48-1.86]), SGA (1.55[0.91-2.64]) and LGA (0.78[0.42-1.45]), P>0.05. Sex-stratified PS matching models with multivariable regression analysis further confirmed that vitrification did not increase the risks of above-mentioned adverse perinatal outcomes in either the male or female infant cohort.

LIMITATIONS, REASONS FOR CAUTION

Although the analysis was adjusted for a number of important confounders, the hospital dataset did not contain other potential confounders such as the medical history and obstetrics outcomes of women during pregnancy to allow adjustment. In addition, the current findings are only applicable to cleavage stage FET, but not pronuclei stage or blastocyst stage ET.

WIDER IMPLICATIONS OF THE FINDINGS

Vitrified ET, in comparison with slow-frozen ET, was not associated with increased risks of adverse neonatal outcomes. With its superiority on live birth rates and non-inferiority on safety perinatal outcomes, transition from slow-freezing to the use of vitrification for embryo cryopreservation is reassuring. Nonetheless, future research is needed for the long-term effects of vitrification method on offspring's health outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Key Research and Development Program (2016YFC100205), Guangzhou Science and Technology Project (201804020087), Guangdong Province Science and Technology Project (2016A020218008) and Guangdong Provincial Key Laboratory of Reproductive Medicine (2012A061400003). The authors have no conflicts of interest to declare.

Utility of Procalcitonin as a Biomarker for Sepsis in Children

Sepsis is a complex process defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. It is associated with significant morbidity and mortality rates in both adults and children, and emphasis has been placed on its early recognition and prompt provision of antimicrobials. Owing to limitations of current diagnostic tests (i.e., poor sensitivity and delayed results), significant research has been conducted to identify sepsis biomarkers. Ideally, a biomarker could reliably and rapidly distinguish bacterial infection from other, noninfectious causes of systemic inflammatory illness. In doing so, a sepsis biomarker could be used for earlier identification of sepsis, risk stratification/prognostication, and/or guidance of antibiotic decision-making. In this minireview, we review one of the most common clinically used sepsis biomarkers, procalcitonin, and its roles in sepsis management in these three areas. We highlight key findings in the adult literature but focus the bulk of this review on pediatric sepsis. The challenges and limitations of procalcitonin measurement in sepsis are also discussed.

[Diagnostic value of procalcitonin in neonatal early-onset sepsis]

OBJECTIVE

To study the value of procalcitonin (PCT) within 3 days after birth in the diagnosis of neonatal early-onset sepsis (EOS), as well as the thresholds of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages.

METHODS

A total of 109 neonates with a confirmed diagnosis of sepsis, 215 neonates with clinically diagnosed sepsis, and 367 neonates without sepsis were enrolled. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. The diagnostic value of PCT and blood culture was compared.

RESULTS

In the confirmed diagnosis group, the neonates with a gestational age of <34 weeks had a significantly higher level of PCT than those with a gestational age of ≥34 weeks (P<0.05). For the neonates with a gestational age of ≥34 weeks, the optimal cut-off values of PCT in the diagnosis of EOS were 1.588 ng/mL (sensitivity 0.688, specificity 0.851) at age of <12 hours, 4.960 ng/mL (sensitivity 0.737, specificity 0.883) at age of 12 - <24 hours, 5.583 ng/mL (sensitivity 0.727, specificity 0.865) at age of 24 - <36 hours, 1.710 ng/mL (sensitivity 0.732, specificity 0.755) at age of 36 - <48 hours, 3.570 ng/mL (sensitivity 0.488, specificity 0.930) at age of 48 -<60 hours, and 3.574 ng/mL (sensitivity 0.333, specificity 0.900) at age of 60 - 72 hours. PCT had a larger area under the ROC curve in the diagnosis of EOS than blood culture within 36 hours after birth (P<0.05).

CONCLUSIONS

The same criteria can be used for late preterm infants (with a gestational age of ≥34 weeks) and full-term infants, while early preterm infants (with a gestational age of <34 weeks) should be considered separately. PCT has different optimal cut-off values in the diagnosis of EOS in neonates with different ages, with a higher value than blood culture in the diagnosis of EOS within 36 hours after birth.

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.

[Clinical value of blood lactate in predicting the prognosis of neonatal sepsis]

OBJECTIVE

To explore the clinical value of arterial blood lactate level in predicting the prognosis of neonatal sepsis.

METHODS

The clinical data of 301 cases of neonatal sepsis were collected, which mainly included biochemical indicators such as blood lactate on admission, C-reactive protein, and procalcitonin. ROC curves were plotted to evaluate the value of lactate level on admission in predicting the prognosis of neonatal sepsis.

RESULTS

The mortality rate was significantly higher for full-term infants in the severely-elevated lactate group than in the mildly-elevated lactate group and the normal lactate group (26.1% vs 3.1% and 0%; P<0.017). The poor prognosis group had a significantly increased lactate level on admission compared with the good prognosis group (6.5±5.1 mmol/L vs 3.6±1.7 mmol/L; P<0.05). The sensitivity and specificity of blood lactate level on admission (cutoff value: 6.15 mmol/L) were 0.545 and 0.919 respectively, in predicting the prognosis of neonatal sepsis.

CONCLUSIONS

Early blood lactate level can be used as a biochemical parameter to predict the prognosis of neonatal sepsis as it has a high specificity but a low sensitivity.

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.