Does serum procalcitonin aid in the diagnosis of bloodstream infection regardless of whether patients exhibit the systemic inflammatory response syndrome?

Construction and efficacy evaluation of an early warning scoring system for septic shock in patients with digestive tract perforation: A retrospective cohort study

Objective

To establish an early warning scoring system for septic shock in patients with digestive tract perforation (DTP) and evaluate its diagnostic efficacy.

Methods

Patients with surgically confirmed or clinically diagnosed DTP admitted to the Department of Intensive Care Medicine of Fujian Provincial Hospital from June 2012 to October 2021 were retrospectively analyzed. General demographic characteristics, perforation-related information, vital signs, common laboratory indicators, and common ICU scores (Glasgow Coma Scale score, Acute Physiology and Chronic Health Evaluation-II score,Sequential Organ Failure Assessment score) were collected. The patients were divided into shock group and non-shock group according to whether the patients had septic shock during hospitalization. The risk factors of septic shock were screened by basic statistical analysis and multivariate Logistic regression analysis. The receiver operating characteristic curve was drawn to determine the cut-off value of the continuous indicators and discretized with reference to clinic, and the corresponding score was set according to the β regression coefficient of each variable.

Results

A total of 176 patients with DTP were included. The average age of the patients was 64.13 ± 14.67 years old, and 74.40% were males. The incidence of septic shock was 30.11% (53/176). Multivariate Logistic regression analysis showed that the highest heart rate≥105 beats/min, Glasgow Coma Scale score≤14 points, lactic acid≥5.75 mmol/L, procalcitonin≥41.47 ug/L, C-reactive protein≥222.5 mg/L were independent risk factors for septic shock in patients with DTP. The total score of clinical diagnostic scoring system of septic shock in patients with DTP was 6 points, including the highest heart rate≥105 beats/min (1 point), lactic acid≥5.75 mmol/L (two points), procalcitonin≥41.47 ug/L (one point), C-reactive protein≥222.5 mg/L (1 point), and Glasgow Coma Scale score≤14 points (1 point). The area under ROC curve (AUC) of this scoring system was 0.789 and the 95% confidence interval was 0.717–0.860 (P < 0.001); when the optimal cut-off value was 2.5, the sensitivity and specificity were 54.70 and 87.80%, respectively.

Conclusion

This new score system has its certain clinical value and has important guiding significance for clinicians to judge the prognosis of patients with DTP in time.

A risk score for early predicting bloodstream infections in febrile obstetric patients: a pilot study

PURPOSE

Early prediction of bloodstream infections (BSI) among obstetric patients remains to be a challenge for clinicians. The objective of this study was to develop a risk score and assess its discriminative ability in febrile obstetric patients in a maternal intensive care unit (ICU).

METHODS

Between May 2015 and August 2020, a total of 497 febrile obstetric patients were categorized into BSI group (n = 276) and Non-BSI group (n = 221) based on the result of blood cultures. White blood cell count, C-reactive protein (CRP), procalcitonin (PCT), time of interval from amniorrhea to fever (IFAF) and maximum body temperature (T_max) were compared between the two groups. All patients were divided into training set (n = 298) and validation set (n = 199). The risk score was established using univariate and multivariate logistic regression from patients in the training set, and its discriminative ability was tested among patients in the validation set.

RESULTS

The levels of neutrophil, CRP, PCT, IFAF and T_max were significantly higher in BSI group than those in Non-BSI group. PROM, T_max, neutrophil and CRP acted as independent predictive factors for BSI in the training set. The area under the receiver operating characteristic curve of risk score for early prediction of BSI in the training, validation set and the whole population was 0.829 (95% CI 0.783-0.876), 0.848 (95% CI 0.792-0.903) and 0.838 (95% CI 0.803-0.873), respectively.

CONCLUSION

The risk score has a feasible discriminatory ability in early prediction of BSI in febrile obstetric patients.

Prognostic value of central venous-to-arterial carbon dioxide difference in patients with bloodstream infection

Background: Bloodstream infection (BSI) are prone to circulation disorders, which portend poor outcome. The central venous-to-arterial carbon dioxide difference (Pcv-aCO₂) is a biomarker for circulation disorders, but the prognostic value of Pcv-aCO₂ in BSI patients remains unclear. This study was to investigate the association of Pcv-aCO₂ with adverse events in BSI patients. Methods: The patients with BSI between August 2014 and August 2017 were prospectively enrolled. Clinical characteristic and laboratory results were collected. We analyzed the association of the level of Pcv-aCO₂ with clinical variables and 28-day mortality. Results: A total of 152 patients were enrolled. The Pcv-aCO₂ was positively correlated with white blood cell count (r=0.241, p=0.003), procalcitonin (r=0.471, p<0.001), C-reactive protein (r=0.192, p=0.018), lactate (r=0.179, p=0.027), Sequential Organ Failure Assessment (r=0.318, p<0.001) and Acute Physiology And Chronic Health Evaluation II score (r=0.377, p<0.001), while that was negatively correlated with central venous oxygen saturation (r=-0.242, p<0.001) and platelet (r=-0.205, p=0.011). Kaplan-Meier curves demonstrated that patients with Pcv-aCO₂ >6mmHg had a worse prognosis than those without (log rank=32.10, p<0.001). Multivariate analysis showed Level of Pcv-aCO₂ was an independent risk factor for 28-day mortality (HR: 3.10, 95% CI: 1.43-6.74, p=0.004). The area under the receiver operating characteristic curve of Pcv-aCO₂ for prediction of 28-day mortality in patients with BSI was 0.794. Pcv-aCO₂>6 mmHg had 81.1% sensitivity and 78.8% specificity for predicting 28-day mortality. Conclusion: Pcv-aCO₂ may be a simple and valuable biomarker to assessment of 28-day mortality in patients with BSI.

The ability of Procalcitonin, lactate, white blood cell count and neutrophil-lymphocyte count ratio to predict blood stream infection. Analysis of a large database

BACKGROUND

The global burden of death due to sepsis is considerable. Early diagnosis is essential to improve the outcome of this deadly syndrome. Yet, the diagnosis of sepsis is fraught with difficulties. Patients with blood stream infection (BSI) are at an increased risk of complications and death. The aim of this study was to determine the diagnostic accuracy of four readily available biomarkers to diagnose BSI in patients with suspected sepsis.

METHODS

In this retrospective, observational, Electronic Medical Record based study we compared the accuracy of procalcitonin (PCT), serum lactate concentration, total white blood cell (WBC) count and the neutrophil-lymphocyte count ratio (NLCR) to diagnose BSI in adult patients presenting to hospital with suspected sepsis. Based on the blood culture results patients were classified into 1 of the following 5 groups: i) negative blood cultures, ii) positive for a bacterial pathogen, iii) positive for a potential pathogen, iv) fungal pathogen and v) potential contaminant. Group 2 was further divided into Gram -ve and Gram +ve pathogens. Receiver operating characteristic (ROC) curves were constructed to compare the diagnostic performance of the biomarkers.

RESULTS

There were 1767 discreet patient admissions. The median PCT concentration differed significantly across blood culture groups (p < 0.0001). The highest median PCT concentration was observed in patients with a Gram-negative pathogen (17.1 ng/mL; IQR 3.6-49.7) and the lowest PCT in patients with negative blood cultures (0.6 ng/mL; IQR 0.2-2.8). The AUROC was 0.83 (0.79-0.86) for PCT, 0.68 (0.64-0.72) for the NLCR, 0.55 (0.51-0.60) for lactate concentration and 0.52 (0.48-0.57) for the WBC count. The AUROC for PCT was significantly greater than that of the NLCR (p < 0.0001). A PCT less than 0.5 ng/mL had a negative predictive value of 95% for excluding BSI. The best cut-off value of PCT for predicting BSI was 1.5 ng/ml.

CONCLUSION

Our results suggest that PCT of less than 0.5 ng/mL may be an effective screening tool to exclude BSI as the cause of sepsis, while the diagnosis of BSI should be considered in patients with a PCT above this threshold. The total WBC count and blood lactate concentration may not be reliable biomarkers for the diagnosis of BSI. The NLCR may be a useful screening test for BSI when PCT assays are not available.

Existe-t-il une plus-value du lactate artériel comparé au lactate veineux dans la prise en charge des patients infectés aux urgences ?

Introduction : La mesure du lactate est une étape cruciale dans l’évaluation des patients septiques aux urgences. Bien que la référence soit le prélèvement artériel, celui-ci est inadapté à la médecine d’urgence, et le prélèvement veineux semble être une alternative potentielle. Ce travail s’est intéressé à décrire la concordance entre Lact-A et Lact-V, et à comparer l’apport pronostique du Lact-A comparativement au Lact-V chez les patients infectés aux urgences.

Matériels et méthode : Étude de cohorte prospective observationnelle menée au centre hospitalier universitaire de Nice entre 2015 et 2017. Ont été inclus les patients présentant une suspicion d’infection avec au moins deux critères cliniques de SIRS. Le lactate a été mesuré de manière concomitante par prélèvement veineux et artériel.

Résultats : Au total, 354 couples Lact-A/Lact-V ont été analysés. Le biais moyen entre les valeurs artérielles et veineuses était de 0,65 ± 0,89 mmol/l, avec des limites d’agrément à 95 % de –2,4 + 1,1 mmol/l. Un Lact-V supérieur à 2,3 mmol/l permettait de confirmer un Lact-A supérieur à 2 mmol/l avec une sensibilité de 94,1 % (IC 95 % : [87,8– 97,3]) et une spécificité de 91,7 % (IC 95 % : [87,6–94,5]). De plus, un Lact-V inférieur à 2 mmol/l permettait de confirmer un Lact-A inférieur à 2 mmol/l avec une VPP de 99 %. L’apport pronostique du Lact-V était globalement similaire au Lact-A mais restait relativement faible.

Conclusion : La lactatémie veineuse apporte des arguments équivalents pour l’évaluation pronostique des patients infectés aux urgences. Par ailleurs, un Lact-V inférieur à 2 mmol/l permet d’affirmer un Lact-A normal permettant de surseoir au prélèvement artériel.

The use of procalcitonin for the management of sepsis in Internal Medicine wards: current evidence

Procalcitonin (PCT) is a circulating polypeptide produced in response to bacterial infections. Studies conducted in the Intensive Care Unit (ICU) setting have demonstrated its utility as a biomarker of bacterial infection and sepsis. Thus, PCT is widely used to distinguish between sepsis and SIRS, and to guide antibiotic therapy. At present sepsis represents a frequent diagnosis among patients admitted to internal medicine (IM) departments. Basing on the knowledge derived from ICU studies, the use of PCT has become routine in non-intensive wards, contributing to improve the management of sepsis. However, some differences between the two populations of patients - the IM being older, affected by multiple chronic comorbidities and lacking of invasive monitoring - could limit the generalizability of ICU results. Most of the studies on PCT conducted in the IM setting have focused on chronic obstructive pulmonary disease, pneumonia and sepsis. Although PCT represents one of the best biomarker available in routine clinical practice, there are uncertainties on the optimal cut-offs to be used for starting or discontinuing antibiotic treatment in patients with suspected bacterial infection or sepsis, for predicting outcome and on the role of PCT variations during antibiotic treatment. Moreover, several diseases can produce an elevation of PCT levels, thus producing false positive results. This represents a narrative review summarizing current evidences on PCT for the management of sepsis in an Internal Medicine wards, highlighting differences with ICU, with a special focus on the role of PCT variations as predictor of outcomes in non-ICU wards.

The Use of Procalcitonin as a Sepsis Marker in a Community Hospital

BACKGROUND

Procalcitonin (PCT) is a biomarker that shows good sensitivity and specificity in identifying septic patients.

METHODS

This study investigated the diagnostic accuracy of PCT in a community hospital setting and how it compared to that of lactic acid. It explored the impact on patient care before and after PCT implementation regarding costs and length of stay. Two comparative groups were analyzed using an exploratory descriptive case-control study with data from a 19-month period after PCT implementation and a retrospective quasi-experimental study using a control group of emergency department patients diagnosed with sepsis using data before PCT implementation.

RESULTS

Post-procalcitonin implementation samples included 165 cases and pre-procalcitonin implementation sample included 69 cases. From the 165 sepsis cases who had positive blood cultures, PCT had a sensitivity of 89.7%. In comparison, lactic acid's sensitivity at the current cutoff of 18.02 mg/dL (2.0 mmol/L) was 64.9%. There was a 32% decrease in median cost before and after PCT implementation, even with the length of stay remaining at 5 days in both time periods.

CONCLUSIONS

There was a significant decrease after the implementation of PCT in cost of hospitalization compared to costs before implementation. This cost is highly correlated with length of stay; neither the hospital nor the intensive care unit length of stay showed a difference with before and after implementation. There was a positive correlation between lactic acid and PCT values. PCT values had a higher predictive usefulness than the lactic acid values.

Performance enhancement of procalcitonin by high-sensitivity C-reactive protein at the optimal cutoff in predicting bacteremia in emergency department adult patients

Pathogenic bacteremia portends a high mortality risk in adult patients admitted to an Emergency Department (ED). This study aims to investigate the effect of adding high-sensitivity C-reactive protein (hs-CRP) to procalcitonin (PCT) and lactate in predicting bacteremia, Gram-negative (GNB) and Gram-positive bacteremia (GPB), using the optimal cutoff derived from the receiver operating characteristics analysis. We evaluated the diagnostic measures, including the positive-test likelihood (LR+), the negative-test likelihood (LR-), and the diagnostic odds ratio (DOR) using a single-center retrospective analysis design. This Standards for Reporting Diagnostic-compliant study comprised 886 consecutive adults who were admitted to the ED in 2010; to this cohort, a 22.2% prevalence of true bacteremia was subsequently confirmed. At the cutoff of 3.9 μg/L, PCT had a DOR of 5.3 (95% confidence interval [CI]: 3.76-7.61) and LR + of 2.8 (95% CI: 2.3-3.4) in predicting overall bacteremia. Elevated PCT and lactate (cutoff at 2 mmol/L), increased the DOR and LR + to 6.3 (95% CI: 4.27-9.29) and 4.0 (95% CI: 3.1-5.2). The DOR and LR + were further improved to 7.1 (95% CI: 4.2-11.95) and 5.6 (95% CI: 3.7-8.6), respectively, when hs-CRP at the cutoff of 1238 nmol/L was added to PCT plus lactate. High-sensitivity CRP at the cutoff of 1,255 nmol/L can enhance the discriminative power raising DOR and LR + values for GPB. The elevation of hs-CRP at the optimal cutoff might improve the diagnostic performance to predict unspecified bacteremia and GPB, but not GNB.

Procalcitonin kinetics after burn injury and burn surgery in septic and non-septic patients - a retrospective observational study

BACKGROUND

Early sepsis diagnosis is crucial for the correct management of burn patients, and it clearly influences outcomes. The systemic inflammatory response triggered by burns mimics sepsis presentation and complicates early sepsis diagnosis. Biomarkers were advocated to aid the diagnosis of early sepsis. Serum procalcitonin (PCT) exhibits fair accuracy and good correlation with sepsis severity, being used in diverse clinical settings. However, few studies have evaluated perioperative changes in PCT levels in burn patients. The present study evaluated PCT kinetics during the first days after burn injury and subsequent surgical interventions to assess PCT utility in distinguishing septic from non-septic inflammatory responses.

METHODS

This study was a retrospective observational study of all burn patients admitted to the Coimbra Burns Unit (Portugal) between January 2011 and December 2014 who presented with a total burn surface area ≥ 15% and who underwent subsequent surgery. PCT kinetics were investigated a) during the first five days after burn injury and b) preoperatively during the five days after surgery in three subsets of patients, including those with no preoperative and no postoperative sepsis (NN), no preoperative but postoperative sepsis (NS), and preoperative and postoperative sepsis (SS). A total of 145 patients met the selection criteria and were included in the analysis.

RESULTS

PCT levels in the first five days after burn injury were significantly higher in patients who developed at least one sepsis episode (n = 85) compared with patients who did not develop sepsis (n = 60). PCT values > 1.00 ng/mL were clearly associated with sepsis. Study participants (n = 145) underwent a total of 283 surgical interventions. Their distribution by preoperative/postoperative sepsis status was 142 (50.2%) in NN; 62 (21.9%) in NS; and 79 (27.9%) in SS. PCT values exhibited a parallel course in the three groups that peaked on the second postoperative day and returned to preoperative levels on the third day or later. The lowest PCT values were found in NN, and the highest values were observed in SS; the NS values were intermediate.

CONCLUSIONS

PCT kinetics coupled with a clinical examination may be helpful for sepsis diagnosis during the first days after burn injury and burn surgery.

High Serum Procalcitonin Concentrations in Patients With Hemorrhagic Fever With Renal Syndrome Caused by Hantaan Virus

Objective: This study analyzed the significance of procalcitonin (PCT) in patients with hemorrhagic fever with renal syndrome (HFRS) caused by Hantaan virus.

Methods: The demographics and clinical and laboratory data including PCT at hospital admission in 146 adults with HFRS were retrospectively analyzed.

Results: PCT level was significantly higher in severe patients (n = 72) than in mild patients (n = 74, p < 0.001) and independently associated with disease severity (OR 2.544, 95% CI 1.330–4.868, p = 0.005). PCT had an area under the receiver operating characteristic curve (AUC) value of 0.738 (95% CI 0.657–0.820, p < 0.001) for predicting severity. PCT level was significantly increased in patients with bacterial infection (n = 87) compared with those without (n = 59, p = 0.037) and associated with bacterial infection (OR 1.685, 95% CI 1.026–2.768, p = 0.039). The AUC value of PCT for predicting bacterial infection was 0.618 (95% CI 0.524–0.711, p = 0.016). PCT level was significantly elevated in non-survivors (n = 13) compared with survivors (n = 133, p < 0.001) and independently associated with mortality (OR 1.075, 95% CI 1.003–1.152, p = 0.041). The AUC value of PCT for predicting mortality was 0.819 (95% CI 0.724–0.914, p < 0.001).

Conclusion: PCT concentrations at admission would be predictive of disease severity, secondary bacterial infection and mortality in patients with HFRS caused by Hantaan virus.

Diagnostic value of serum procalcitonin, lactate, and high-sensitivity C-reactive protein for predicting bacteremia in adult patients in the emergency department

BACKGROUND

Few studies compared the diagnostic value of procalcitonin with a combination of other tests including lactate and high-sensitivity C-reactive protein in the prediction of pathogenic bacteremia in emergency department adult patients.

METHODS

We performed a retrospective study assessing the differences in performances of procalcitonin at a cutoff of 0.5 ng/mL, lactate at a cutoff of 19.8 mg/dL, high-sensitivity C-reactive protein at a cutoff of 0.8 mg/dL and their combinations for predicting bacteremia in emergency department adult patients. Sensitivity, specificity, overall accuracy, positive-test and negative-test likelihood, and diagnostic odds ratio with 95% confidence interval for each test combination were calculated for comparison. The receiver operating characteristic curve for every single test were compared using DeLong's method. We also performed a sensitivity analysis in two expanded patient cohorts to assess the discriminative ability of procalcitonin or test combination.

RESULTS

A total of 886 patients formed the initial patient cohort. The area under the receiver operating characteristic curve for discriminating positive blood culture was: procalcitonin = 0.72 (95% CI [0.69-0.75]) with a derived optimal cutoff at 3.9 ng/mL; lactate 0.69 (0.66-0.72) with an optimal cutoff at 17.9 mg/dL; high-sensitivity C-reactive protein 0.56 (0.53-0.59) with an optimal cutoff of 13 mg/dL; with pairwise comparisons showing statistically significant better performance of either procalcitonin or lactate outperforming high-sensitivity C-reactive protein. To predict positive blood cultures, the diagnostic odds ratio for procalcitonin was 3.64 (95% CI [2.46-5.51]), lactate 2.93 (2.09-4.14), and high-sensitivity C-reactive protein 0.91 (0.55-1.55; P = 0.79). About combined tests, the diagnostic odds ratio for procalcitonin and lactate increases were 3.98 (95% CI [2.81-5.63]) for positive blood culture prediction. Elevated procalcitonin level rendered a six-fold increased risk of positive gram-negative bacteremia with a diagnostic odds ratio of 6.44 (95% CI [3.65-12.15]), which showed no further improvement in any test combinations. In the sensitivity analysis, as a single test to predict unspecified, gram-negative and gram-positive bacteremia, procalcitonin performed even better in an expanded cohort of 2,234 adult patients in terms of the diagnostic odds ratio.

DISCUSSIONS

For adult emergency patients, procalcitonin has an acceptable discriminative ability for bacterial blood culture and a better discriminative ability for gram-negative bacteremia when compared with lactate and high-sensitivity C-reactive protein. High-sensitivity C-reactive protein at a cutoff of 0.8 mg/dL performed poorly for the prediction of positive bacterial culture.