Procalcitonin for the diagnosis of early-onset neonatal sepsis: A multilevel probabilistic approach

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.

Cell Population Data (CPD) for Early Recognition of Sepsis and Septic Shock in Children: A Pilot Study

Objectives: Innovative Cell Population Data (CPD) have been used as early biomarkers for diagnosing sepsis in adults. We assessed the usefulness of CPD in pediatric patients with sepsis/septic shock, in terms of early recognition and outcome prediction. We revised 54 patients (0-15 y) admitted to our Pediatric Intensive Care Unit (PICU) for sepsis/septic shock during a 4-year period. Twenty-eight patients were excluded, 26 septic patients were enrolled (G1). Forty children admitted for elective surgery served as controls (G2). Data on five selected CPD parameters, namely neutrophils fluorescence intensity (NE-SFL), monocytes cells complexity (MO-X), monocytes fluorescence intensity (MO-Y), monocytes complexity and width of dispersion of events measured (MO-WX), and monocytes cells size and width dispersion (MO-WZ), were obtained at time of PICU admission (t0) by a hematological analyzer (Sysmex XN 9000®). As the primary outcome we evaluated the relevance of CPD for diagnosing sepsis/septic shock on PICU admission. Furthermore, we investigated if CPD at t0 were correlated with C-reactive protein (CRP), patient survival, or complicated sepsis course. Results: On PICU admission (t0), NE-SFL, MO-WX, and MO-Y were higher in sepsis/septic shock patients compared to controls. NE-SFL values were correlated with CRP values in G1 patients (r = 0.83). None of the five CPD parameters was correlated with survival or complicated sepsis course. Conclusion: We found higher values of NE-SFL, MO-WX, and MO-Y in children with sepsis/septic shock upon PICU admission. These parameters may be a promising adjunct for early sepsis diagnosis in pediatric populations. Larger, prospective studies are needed to confirm our preliminary observations.

A 2020 review on the role of procalcitonin in different clinical settings: an update conducted with the tools of the Evidence Based Laboratory Medicine

Biomarkers to guide antibiotic treatment decisions have been proposed as an effective way to enhancing a more appropriate use of antibiotics. As a biomarker, procalcitonin (PCT) has been found to have good specificity to distinguish bacterial from non-bacterial inflammations. Decisions regarding antibiotic use in an individual patient are complex and should be based on the pre-test probability for bacterial infection, the severity of presentation and the results of PCT serum concentration. In the context of a high pre-test probability for bacterial infections and/or a high-risk patient with sepsis, monitoring of PCT over time helps to track the resolution of infection and decisions regarding early stop of antibiotic treatment. As outlined by the Evidence Based Laboratory Medicine (EBLM), not only the pre-test probability but also the positive likelihood ratio influence the performance of a test do be really diagnostic. This aspect should be taken into account in the interpretation of the results of clinical trials evaluating the performance of PCT in guiding antibiotic therapy.

Efficacy and safety of applying a neonatal early-onset sepsis risk calculator in China

AIM

To evaluate and compare the performance of the early-onset sepsis (EOS) risk calculator with procalcitonin (PCT), complete blood count (CBC) and C-reactive protein (CRP) for predicting neonatal EOS.

METHODS

This was a retrospective case-control study of neonates who were ≥34 weeks of gestation and ≤12 h of age at admission to our hospital between January 2017 and December 2018. Neonates with strictly defined EOS and those without evidence of infection were included in this study. We reviewed and collected the laboratory data and medical charts of the included neonates. The EOS risk scores for all neonates were calculated using the EOS risk calculator, and the results were analysed and compared with blood biomarkers.

RESULTS

A total of 501 neonates, including 353 infected and 148 uninfected infants, met the inclusion criteria for the study. Comparing these predictors, PCT had the best predictive value (sensitivity: 87.5%, specificity: 95.5%), closely followed by the EOS risk calculator (sensitivity: 81.16%, specificity: 93.92%). Multivariate logistic regression found that risk scores calculated by the EOS risk calculator had strong associations with EOS as an independent risk factor (odds ratio: 57.37, P < 0.05). The combination of the EOS risk calculator, PCT, CBC and CRP could increase the predictive value of the model and reach an area under the receiver operating characteristic curve of 0.987 for predicting EOS.

CONCLUSIONS

In this pilot study, applying the EOS calculator in China, the EOS risk calculator and PCT showed good predictive value compared to CBC and CRP. Risk scores from the EOS risk calculator strongly correlated with EOS, and the EOS risk calculator offered increased predictive value when used in combination with blood biomarkers.

Establishment of reference intervals for maternal blood and umbilical cord blood procalcitonin in healthy Chinese women in late pregnancy

AIM

To establish reference intervals (RIs) for maternal blood and umbilical cord blood procalcitonin (PCT) in healthy Chinese women in late pregnancy.

METHODS

One hundred and twenty-seven healthy Chinese women in late pregnancy, including 70 vaginal deliveries and 57 cesarean section deliveries, were retrospectively analyzed. These pregnant women gave birth to 58 male infants and 69 female infants. Another 127 age-matched healthy women who were not pregnant were enrolled as the control group. PCT levels in maternal blood, umbilical cord blood and control blood were determined using electrochemiluminescence immunoassay. The RIs of PCT were defined using an intermediate 95% interval.

RESULTS

The RIs for maternal blood and umbilical cord blood PCT were 0.020-0.075 ng/mL and 0.020-0.159 ng/mL, respectively. The cord blood PCT level was not significantly different between different delivery methods (P > 0.05). In contrast, the umbilical cord blood PCT in female newborns was higher than that in male newborns (0.088 ± 0.046 ng/mL vs 0.072 ± 0.030 ng/mL, P < 0.05).

CONCLUSION

Maternal blood and umbilical cord blood PCT of Chinese women in late pregnancy have different RIs, and umbilical cord blood PCT level is affected by the gender of newborns.

Prediction of histological chorioamnionitis and neonatal and infantile outcomes using procalcitonin in the umbilical cord blood and amniotic fluid at birth

Aim

We aimed to clarify the usefulness of procalcitonin (PCT) in the evaluation of histological chorioamnionitis (CAM) and in the prediction of neonatal and infantile outcomes as a reference of interleukin‐6 (IL‐6).

Methods

Subjects were 36 singleton pregnant women delivered at 22–37 weeks’ gestation due to threatened premature delivery and/or preterm premature rupture of membranes. Cases were classified into the CAM and non‐CAM groups, according to Blanc's criteria. Comparisons were made on umbilical venous and amniotic fluid PCT levels among the groups. The relations between umbilical venous PCT and IL‐6 levels and neonatal and infantile outcomes were also analyzed.

Results

The umbilical venous PCT level in the CAM group (240.2 pg/mL, 125.4–350.3 pg/mL: median, first quartile–third quartile) was higher than that in the non‐CAM group (105.1, 50.2–137.5 pg/mL; P = 0.0006). There were no differences in the amniotic fluid PCT levels between the groups. There was a strong correlation between umbilical venous PCT and IL‐6 levels (correlation coefficient: 0.793). Among 10 cases with an umbilical venous PCT level of ≥170.0 pg/mL and six cases with IL‐6 ≥ 11.0 pg/mL, six (60.0%) and five cases (83.3%), respectively, had adverse neonatal and infantile outcomes. Among seven cases with adverse neonatal and infantile outcomes, six (85.7%) and five (71.4%) cases showed umbilical venous PCT levels of ≥170.0 pg/mL and IL‐6 levels of ≥11.0 pg/mL, respectively.

Conclusion

Similar to IL‐6, the umbilical venous PCT level is a promising parameter for predicting histological CAM and adverse neonatal and infantile outcomes related to in utero inflammatory status.

The Determination of Procalcitonin Concentration in Early-Onset Neonatal Infection

The aim of this study was to assess the clinical usefulness of blood procalcitonin (PCT) levels for the diagnosis and therapeutic monitoring of early-onset neonatal sepsis (EONS). PCT as well as C-reactive protein (CRP) levels and white blood cell (WBC) count were measured in venous blood from 57 infected and 72 uninfected neonates. Differences between groups for PCT, CRP, and WBC levels were significant. The threshold value on the receiver operating characteristic curve in the prediction of EONS was 5.33 ng/mL for PCT, 9.3 mg/L for CRP, and 14.9 × 10⁹/L for WBC. There was no effect of antibiotic administered to the mother on PCT, CRP, and WBC levels in neonatal blood sampled before treatment of EONS. Evidently reduced PCT levels are observed after 2 days of treatment. The authors conclude that prenatal antibiotic therapy does not reduce the value of PCT levels in blood for the diagnosis of EONS.

The influencing factors on procalcitonin values in newborns with noninfectious conditions during the first week of life

Purpose

Although procalcitonin (PCT) level is useful for the diagnosis of neonatal sepsis, PCT reliability is inconsistent because of the varied conditions encountered in neonatal intensive care units. This study aimed to investigate PCT levels and factors influencing increased PCT levelin newborns without bacterial infection during the first week of life.

Methods

In newborns hospitalized between March 2013 and October 2015, PCT levels were measured on the first, third, and seventh days after birth. Newborns with proven bacterial (blood culture positive for bacteria) or suspicious infection (presence of C-reactive protein expression or leukocytosis/leukopenia) were excluded. Various neonatal conditions were analyzed to identify the factors influencing increased PCT level.

Results

Among 292 newborns with a gestational age of 35.2±3.0 weeks and a birth weight of 2,428±643 g, preterm newborns (n=212) had higher PCT levels than term newborns (n=80). Of the newborns, 7.9% had increased PCT level (23 of 292) on the firstday; 28.3% (81 of 286), on the third day; and 3.3% (7 of 121), on the seventh day after birth. The increased PCT level was significantly associated with prenatal disuse of antibiotics (P=0.004) and surfactant administration (P<0.001) on the first day after birth, postnatal use of antibiotics (P=0.001) and ventilator application (P=0.001) on the third day after birth, and very low birth weight (P=0.042) on the seventh day after birth.

Conclusion

In newborns without bacterial infection, increased PCT level was significantly associated with lower gestational age and respiratory difficulty during the first week of life. Further studies are needed for clinical applications.

Procalcitonin levels predict infectious complications and response to treatment in patients undergoing cytoreductive surgery for peritoneal malignancy

BACKGROUND

Cytoreductive-surgery for peritoneal-malignancy (PM) involves extensive intra-abdominal surgery and a massive post-operative systemic-inflammatory-response (SIRS). It is often challenging to differentiate SIRS that are solely surgery-associated from those of post-operative infections. White-Cell-Counts (WCC) and C-Reactive-Protein (CRP) are routinely used as markers for infection, but are non-specific and their elevation is often delayed in PM cases. Other markers need to be evaluated to assist early identification/prediction of post-operative infections.

METHODOLOGY

Prospective evaluation of serum procalcitonin (PCT), CRP and WCC in 50 patients pre-operatively (Day0), and on post-operative days (POD) 1, 3 & 6, following cytoreductive-surgery with or without splenectomy.

RESULTS

Day0 PCT, CRP and WCC values were within normal limits, but increasing physiologically in post-operative period without infection, with noticeable higher PCT in splenectomized patients. In our cohort post-operative infections were diagnosed in 14 patients, often within 48 h. There was a trend for faster rise in serum PCT on POD1 compared to CRP and WCC, and faster PCT decline following appropriate therapy on POD3 and POD6 when infected cases were clinically resolving while WCC and CRP continued to rise, particularly in non-spelenectomised patients. The AUC on POD1 was significantly higher for PCT (0.689) vs. WCC (0.476) and CRP (0.477) (p = 0.04). Sensitivity, specificity, positive-predictive-value and negative-predictive-values for PCT ranged between (57%-100%), (22%-74%), (33%-47%) & (81%-100%), for CRP (28%-78%), (5.5%-86%), (18%-44.4%) & (40%-75.5%) and for WCC (14%-26.5%), (65.5-80.5%), (22%-25%), (67%-70%) respectively.

CONCLUSION

PCT, like WCC and CRP, needs to be interpreted with extreme cautions in the context of infections post-cytoreductive-surgery and should only be used in association with other clinical and investigational findings.

Early-Onset Neonatal Sepsis: Still Room for Improvement in Procalcitonin Diagnostic Accuracy Studies

To perform a systematic review assessing accuracy and completeness of diagnostic studies of procalcitonin (PCT) for early-onset neonatal sepsis (EONS) using the Standards for Reporting of Diagnostic Accuracy (STARD) initiative.EONS, diagnosed during the first 3 days of life, remains a common and serious problem. Increased PCT is a potentially useful diagnostic marker of EONS, but reports in the literature are contradictory. There are several possible explanations for the divergent results including the quality of studies reporting the clinical usefulness of PCT in ruling in or ruling out EONS.We systematically reviewed PubMed, Scopus, and the Cochrane Library databases up to October 1, 2014. Studies were eligible for inclusion in our review if they provided measures of PCT accuracy for diagnosing EONS. A data extraction form based on the STARD checklist and adapted for neonates with EONS was used to appraise the quality of the reporting of included studies.We found 18 articles (1998-2014) fulfilling our eligibility criteria which were included in the final analysis. Overall, the results of our analysis showed that the quality of studies reporting diagnostic accuracy of PCT for EONS was suboptimal leaving ample room for improvement. Information on key elements of design, analysis, and interpretation of test accuracy were frequently missing.Authors should be aware of the STARD criteria before starting a study in this field. We welcome stricter adherence to this guideline. Well-reported studies with appropriate designs will provide more reliable information to guide decisions on the use and interpretations of PCT test results in the management of neonates with EONS.

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.

Impact of sepsis on the urinary level of interleukin-18 and cystatin C in critically ill neonates

BACKGROUND

Urinary interleukin-18 (uIL-18) and cystatin C (uCysC) are biomarkers of acute kidney injury (AKI). We hypothesized that in non-AKI neonates, the level of uIL-18 and uCysC would be higher in those with sepsis compared to those without sepsis. The aims of this study were to determine the association between urinary biomarkers and sepsis in non-AKI critically ill neonates, and to evaluate whether uIL-18 and uCysC could serve as predictors of sepsis in this population.

METHODS

The study included 111 non-AKI critically ill neonates with acute clinical deterioration suggestive of sepsis: 26 with infection, 57 without infection, and 28 were assigned to the unclassified group. Urinary samples were collected and a full sepsis screen was performed at the time of enrollment.

RESULTS

The level of uIL-18, but not uCysC, was significantly elevated in non-AKI septic neonates. Urinary IL-18 was an independent factor associated with sepsis assessed by multivariate analysis, had odds ratio of 1.73 (95 % CI 1.15 to 2.58, p = 0.008), and achieved the area under the receiver operating characteristic curve of 0.74 for predicting the presence of sepsis in non-AKI critically ill neonates.

CONCLUSIONS

Sepsis has an impact on the level of uIL-18, but not on the uCysC in non-AKI neonates, suggesting systemic infection might influence the diagnostic value of uIL-18 to detect AKI in the general population.

Diagnostic Value of Simultaneous Measurement of Procalcitonin, Interleukin-6 and hs-CRP in Prediction of Early-Onset Neonatal Sepsis

Neonatal sepsis is a major cause of morbidities and mortalities mostly remarkable in the third world nations.We aimed to assess the value of simultaneous measurement of procalcitonin (PCT) and interleukin-6 (IL-6) in association with high sensitive- C reactive protein(hs-CRP) in prediction of early neonatal sepsis.A follow-up study was performed on 95 neonates who were below 12 hours (h) of age and had clinical signs of sepsis or maternal risk factors for sepsis. Neonates were assigned to 4 groups including "proven early-onset sepsis", "clinical early-onset sepsis", "negative infectious status", and "uncertain infectious status". Blood samples were obtained within the first 12 h of birth repeated between 24 hours and 36 hours of age for determination of serum levels of PCT, IL-6, hs-CRP, and white blood cell (WBC) count.On admission, neonates with sepsis had a higher WBC count, IL-6, PCT, and hs-CRP levels compared with those neonates without sepsis. This remained significant even after 12-24 hours of admission. Also, patients with clinical evidences of sepsis had a higher serum level of PCT and IL-6 within 12-24 hours after admission compared to the patients with uncertain sepsis.The combination of PCT and IL-6 yielded had a sensitivity of 88% and PCT and CRP (using the cutoff value of 8 mg/L) a sensitivity of 82%.The areas under the ROC curve for the two periods were 0.801, and 0.819 respectively.In final The combination of IL-6, hs-CRP, and PCT seems to be predictive in diagnosis of early onset neonatal sepsis.

[The role of infection in preterm birth]

Intrauterine infection could be responsible for 25% up to 40% of preterm births. This relationship was initially demonstrated using animal models, inducing their abortion by injecting bacteria or endotoxins. In human research, examination of amniocentesis fluid showed the anteriority of infection over labor induction, and the existence of a subclinical latency phase between these two phenomena. The ascending route is preponderant, and four stages can be distinguished: cervical and vaginal infection, chorio-decidual infection, intra-amniotic infection, fetal infection. The intrauterine infection is very frequent in case of early preterm birth (<30 WG). It is associated with an increase of neurological and pulmonary morbidity. Most commonly found bacterial species are mycoplasma species, but also Escherichia coli, Gardnerella vaginalis and streptococcus B. Several markers of the infection have been studied: a maternal leukocytosis>15,000/mm(3) or a C-Reactive Protein (CRP)>20mg/l, an increase of fibronectin and/or IL-6 cervical, a short cervical length especially before 32 WG, a leukocytosis of the amniotic fluid, and/or high interleukin concentrations. The main marker used for the newborn is the CRP, but other markers can also be used for an early diagnosis of an infection, especially interleukin 6.

Biomarkers for diagnosis of neonatal infections: A systematic analysis of their potential as a point-of-care diagnostics

BACKGROUND

Neonatal infections annually claim lives of 1.4 million neonates worldwide. Until now, there is no ideal diagnostic test for detecting sepsis and thus management of possible sepsis cases often depends on clinical algorithm leading to empirical treatment. This often results in unnecessary antibiotic use, which may lead to emergence of antibiotic resistance. Biomarkers have shown great promise in diagnosis of sepsis and guiding appropriate treatment of neonates. In this study, we conducted a literature review of existing biomarkers to analyze their status for use as a point-of-care diagnostic in developing countries.

METHODS

PubMed and EMBASE database were searched with keywords, 'infections', 'neonates', and 'biomarkers' to retrieve potentially relevant papers from the period 1980 to 2010. Leading hospitals and manufacturers were communicated to inquire about the cost, laboratory requirements and current standing of biomarkers in clinical use.

RESULTS

The search returned 6407 papers on biomarkers; 65 were selected after applying inclusion and exclusion criteria. Among the studies, C-reactive protein (CRP), procalcitonin (PCT) and interleukin 6 (IL-6) were the most widely studied biomarkers and were considered to be most promising for diagnosing neonatal infections. About 90% of the studies were from developed countries; more than 50% were from Europe.

CONCLUSIONS

Extensive work is being performed to find the diagnostic and prognostic value of biomarkers. However, the methodologies and study design are highly variable. Despite numerous research papers on biomarkers, their use in clinical setting is limited to CRP. The methods for detection of biomarkers are far too advanced to be used at the community level where most of the babies are dying. It is important that a harmonized multi-site study is initiated to find a battery of biomarkers for diagnosis of neonatal infections.

Serum bone alkaline phosphatase in assessing illness severity of infected neonates in the neonatal intensive care unit

Background: Infections can influence bone metabolism of neonates, which may lead to changes in some bone metabolism biomarkers. The purpose of this study was to determine whether serum bone alkaline phosphatase (BALP), osteocalcin (OC) and beta carboxy-terminal peptide of type I collagen (CTX), as specific biomarkers of bone metabolism, can be used to assess the severity of neonatal infections.

Methods: Sixty-three neonates in the NICU were enrolled in this study. The neonates were divided into infected group (n=33) and non-infected group (n=30). The scores for neonatal acute physiology-perinatal extension II (SNAPPE-II) were calculated and interleukin-6 (IL-6), procalcitonin (PCT), BALP, OC and CTX were measured among the neonates with or without infections, and among the infected neonates before and after treatment.

Results: The serum BALP levels were lower in the infected group than that in the non-infected group (p<0.01). The serum BALP levels increased markedly in the infected neonates after treatment (p<0.01). The serum BALP levels were also inversely correlated with SNAPPE-II of infected neonates before and after treatment (r=-0.56, p<0.05; r=-0.37, p<0.05, respectively). In infected neonates, the differences between serum BALP levels before and after treatment were inversely correlated with those of IL-6 levels (p<0.05). There were no significant changes in the OC, CTX and PCT levels in the infected or non-infected group before and after treatment.

Conclusion: Our data suggest that serum BALP level might be used as a marker for assessing the severity of illness in infected neonates.

Procalcitonin measurement at 24 hours of age may be helpful in the prompt diagnosis of early-onset neonatal sepsis

BACKGROUND

The clinical signs of early-onset neonatal sepsis (EONS) are nonspecific and indistinguishable from those of noninfectious disorders. The early diagnosis of EONS is difficult, but is essential to improve outcomes. The aim of this study was to determine the diagnostic value of procalcitonin (PCT) at birth and at 24h of age in the prompt diagnosis of EONS.

METHODS

The patient group consisted of neonates with a Töllner score of ≥ 10 or a Töllner score of 5-10 but with the presence of prolonged rupture of the membranes (> 18 h) or chorioamnionitis or maternal fever (n=171). The control group (n=89) comprised neonates admitted to the neonatal intensive care unit for different disease entities. Procalcitonin levels at birth (first) and at 24h of age (second) were measured for each neonate in both of the study groups.

RESULTS

There was no difference between the two groups in terms of gender, birth weight, or gestational age. The mean (min-max) first PCT level was 0.48 (0.07-3.48)ng/ml in the controls and 0.51 (0.09-28.6)ng/ml in patients. The mean (min-max) second PCT level was 1.72 (0.21-18.23)ng/ml in the controls and 16.17 (0.17-100)ng/ml in patients. There was no statistically significant difference in PCT levels between the patient and control groups at birth. However, at 24h of age, PCT levels were significantly higher in the patient group than in the control group (p<0.001). Serum PCT levels in controls at 24h of age were slightly increased compared to levels at birth, but as a normal reaction. PCT thresholds for the diagnosis of sepsis were 0.59 ng/ml at birth (sensitivity 48.7%, specificity 68.6%) and 5.38 ng/ml at 24h of life (sensitivity 83.3%, specificity 88.6%).

CONCLUSIONS

In EONS, PCT measurements at birth may initially be normal; a serial PCT measurement at 24h of age may be more helpful for an early diagnosis. During the first 24h of life PCT is a more sensitive marker of infection than C-reactive protein. Further studies are needed to confirm our findings.

Reduction in antibiotic use through procalcitonin testing in patients in the medical admission unit or intensive care unit with suspicion of infection

We report an evaluation of the utility of serum procalcitonin (PCT) measurement as an additional diagnostic tool to support initiating or withholding antibiotics in clinical situations where there is a clinical suspicion of infection but the diagnosis is uncertain. During a six-month period, 99 patients on the medical admission unit (MAU) with suspected infection, and 42 patients on the intensive care unit (ICU) with clinical signs or physiological parameters suggesting possible new infection, had serum PCT concentration measured with the result available within 90min of the request. The test was initiated by the microbiology/infection team during clinical consultations to support the antibiotic decision. On the basis of low PCT values, antibiotics were withheld in MAU on 52 occasions and in ICU on 42 occasions. Patients were followed up prospectively for a week. There was neither progression of bacterial infection requiring antibiotics, nor complications or infection-related mortality in any patients who were denied antibiotics on either MAU or ICU. Without the PCT value it is likely that all of these patients would have received empirical antibiotics. Reduction in unnecessary antibiotic usage was made without any adverse effects on these patients and there was a clear reduction in antibiotic prescribing with cost reduction implications. PCT has the potential to become a valuable tool in antibiotic management.

Serum procalcitonin as a diagnostic marker for neonatal sepsis: a systematic review and meta-analysis

PURPOSE

To assess the value of serum procalcitonin (PCT) for the differentiation between patients with and without neonatal sepsis.

METHODS

We systematically searched PubMed, Scopus, and the Cochrane Library for studies evaluating PCT in neonatal sepsis. PCT had to be measured in neonatal blood samples, at the initial presentation of patients with suspected sepsis, before the administration of antibiotics. We performed a bivariate meta-analysis of sensitivity and specificity, and constructed a hierarchical summary receiver-operating characteristic (HSROC) curve.

RESULTS

Overall, 29 studies eligible for inclusion were identified. We analyzed the 16 studies (involving 1,959 neonates) that evaluated PCT in neonates with culture-proven or clinically diagnosed sepsis in comparison with ill neonates with other conditions. The pooled (95% confidence interval) sensitivity and specificity were 81% (74-87%) and 79% (69-87%), respectively. The area under the HSROC curve (AUC) was 0.87. The diagnostic accuracy of PCT seemed higher for neonates with late-onset sepsis (>72 h of life) than for those with early onset sepsis; the AUC for these analyses was 0.95 and 0.78, respectively. However, fewer data were available for late-onset sepsis. High statistical heterogeneity was observed for all analyses.

CONCLUSION

Our findings suggest that serum PCT at presentation has very good diagnostic accuracy (AUC = 0.87) for the diagnosis of neonatal sepsis. However, in view of the marked observed statistical heterogeneity, along with the lack of a uniform definition for neonatal sepsis, the interpretation of these findings should be done with appropriate caution.