The role of procalcitonin in a decision tree for prediction of bloodstream infection in febrile patients

Accuracy of procalcitonin for diagnosing sepsis in adult patients admitted to the emergency department: a systematic review and meta-analysis

BACKGROUND

Differentiating sepsis from non-infectious systemic inflammatory response syndrome (SIRS) is challenging. Biomarkers like procalcitonin (PCT) aid early risk assessment and guide antibiotic use. This study aims to ascertain PCT's accuracy as a sepsis biomarker among adult emergency department admissions.

METHOD

The PRISMA guidelines were followed to search for relevant articles in five electronic databases between April 14th and August 4th, 2023: PubMed, Cochrane Library, ProQuest, EMBASEs, and ScienceDirect. Studies had to be published in English to avoid directly translating scientific terms. Besides, the inclusion criteria were based on the diagnosis of sepsis in adult patients admitted to an emergency department. QUADAS-2 tool provided by the Review Manager version 5.4.1 was utilized to assess the risk of bias in included studies. STATA (v. 16) software was used to perform the meta-analysis.

RESULTS

Ten of 2457 studies were included. We sampled 2980 adult sepsis patients for the under-investigated role of PCT in ED sepsis diagnosis. PCT emerged as the primary early diagnostic biomarker with high levels (29.3 ± 85.3 ng/mL) in sepsis patients. Heterogeneity in outcomes, possibly due to bias in cohort and observational studies, was observed.

CONCLUSION

PCT tests offer moderate accuracy in diagnosing sepsis and stand out for rapidly and precisely distinguishing between viral and bacterial inflammations.

Clinical utility of procalcitonin in severe odontogenic maxillofacial infection

BACKGROUND

Most of the maxillofacial infections are bacterial infections, and there is a possibility that systemic infections occur by maxillofacial infections. The aim of this study was to investigate the diagnostic value of procalcitonin in patients with odontogenic bacterial infections of the maxillofacial region.

METHODS

We enrolled sixty patients, who were admitted with odontogenic maxillofacial infection from September 2018 to March 2020. White blood cell counts, C-reactive protein, and procalcitonin concentrations were evaluated. Sixty patients were classified into two groups, sepsis and non-sepsis groups, based on systemic inflammatory response syndrome. A Student t test was performed to statistically analyze the difference in inflammatory markers between sepsis and non-sepsis groups.

RESULTS

The mean procalcitonin values on admission were 7.24 ng/mL (range, 0.09-37.15 ng/mL) and 0.40 ng/mL (range, 0.02-4.94 ng/mL) in the sepsis group and non-sepsis group, respectively. The procalcitonin values between the two groups showed a significant difference (P < 0.05). The area under the curve of procalcitonin was 0.927 (P < 0.001), and the cutoff value of procalcitonin that maximizes the area under the curve was calculated to be 0.87 ng/mL.

CONCLUSIONS

According to our study, routine laboratory tests have insufficient accuracy in diagnosing sepsis syndrome. Therefore, it is strongly recommended to perform the procalcitonin test in patients with maxillofacial infection in addition to the conventional laboratory tests to diagnose the systemic inflammatory condition of the patients.

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.

Serum procalcitonin concentration within 2 days postoperatively accurately predicts outcome after liver resection

Background:

Relatively high mortality and morbidity rates are reported after liver resection (LR). However, the early predictors of complications after LR are not clear. This study was performed to clarify the usefulness of procalcitonin (PCT) for the early prediction of complications after elective LR.

Methods:

This observational study included 72 consecutive patients who underwent elective LR from December 2015 to March 2017. Patients were categorized into two groups: those with and without postoperative complications (Clavien-Dindo grade ≥II). The values of postoperative inflammatory markers (white blood cell [WBC] count, C-reactive protein [CRP] and PCT) were compared between the two groups.

Results:

CRP and PCT were significantly higher in patients with than without complications; however, the WBC count showed no difference within 5 days postoperatively. The maximum area under the receiver operating characteristic curves within 2 days after LR using the WBC count, CRP and PCT were 0.608, 0.697 and 0.860, respectively, PCT had the best predictive ability in the early postoperative period. The PCT level peaked within 2 days postoperatively in 61 patients (85%). The maximum PCT level within 2 days postoperatively (PCT1−2) was significantly higher in patients with than without complications (0.52 vs. 0.19 ng/mL, p<0.001). A cutoff PCT1−2 level of 0.35 ng/mL achieved 80% sensitivity and 83% specificity. In patients without complications, there was no difference in PCT1−2 even when the surgical procedure differed (p=0.935).

Conclusions:

PCT1−2 is an early predictive marker after LR and can be similarly used regardless of the LR procedure.

Clinical usefulness of serum 2'-5'-oligoadenylate synthetase for early diagnosis of viral infections among febrile adult patients

BACKGROUND

This study aimed to evaluate the clinical usefulness of serum 2'-5'-oligoadenylate synthetase (2-5AS) levels in diagnosing viral infection.

METHODS

2-5AS, procalcitonin (PCT) and C-reactive protein (CRP) serum levels and leukocyte counts were evaluated in 104 febrile patients (26 viral and 55 bacterial infections, 23 non-infectious diseases).

RESULTS

Assessment of areas under the receiver-operator characteristic curves revealed that 2-5AS and CRP levels and the age of the patient differentiated between viral and bacterial infections, 2-5AS levels differentiated between viral infection and non-infectious disease and PCT levels differentiated between bacterial infection and non-infectious disease. The decision tree constructed according to the results correctly classified the origin of fever in 88 of 104 patients (85%).

CONCLUSIONS

2-5AS is a useful diagnostic biomarker for viral infections and combining it with the PCT and CRP levels and leukocyte counts improves determination of causes of fever.

Update on procalcitonin measurements

Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible pitfalls. The classic indications for PCT measurement are: (i) confirmation or exclusion of diagnosis of sepsis, severe sepsis, or septic shock, (ii) severity assessment and follow up of systemic inflammation mainly induced by microbial infection, and (iii) individual, patient adapted guide of antibiotic therapy and focus treatment. Using serially monitored PCT levels, the duration and need of antibiotic therapy can be better adapted to the individual requirements of the patient. This individualized approach has been evaluated in various studies, and it is recommended to be a part of an antibiotic stewardship program.

Study on TCM Syndrome Identification Modes of Coronary Heart Disease Based on Data Mining

Coronary heart disease (CHD) is one of the most important types of heart disease because of its high incidence and high mortality. TCM has played an important role in the treatment of CHD. Syndrome differentiation based on information from traditional four diagnostic methods has met challenges and questions with the rapid development and wide application of system biology. In this paper, methods of complex network and CHAID decision tree were applied to identify the TCM core syndromes of patients with CHD, and to establish TCM syndrome identification modes of CHD based on biological parameters. At the same time, external validation modes were also constructed to confirm the identification modes.

Predicting bacteremia by procalcitonin levels in patients evaluated for sepsis in the emergency department

Evaluation of: Riedel S, Melendez JH, An AT, Rosenbaum JE, Zenilman JM. Procalcitonin as a marker for the detection of bacteremia and sepsis in the emergency department. Am. J. Clin. Pathol. 135(2), 182-189 (2011). In a recent report, Riedel et al. proposed a procalcitonin cutoff of 0.1 ng/ml to rule out bacteremia in adult patients presenting to the emergency department with systemic infections. Procalcitonin levels were higher in patients with true bacteremia than in patients with negative blood cultures or bacteremia due to possible contaminants. For prediction of bacteremia, a procalcitonin level of 0.1 ng/ml had an excellent negative predictive value of 96.3%, and a good sensitivity of 75%, specificity of 70.6% and area under the curve of 0.73, but poor positive predictive value of 12.8%. Based on the results in this study, we propose that a procalcitonin value of 0.1 ng/ml or less could be used to rule out bacteremia (NPV: 96.3%).

Procalcitonin as a marker for the detection of bacteremia and sepsis in the emergency department

Rapid diagnosis of bloodstream infections (BSIs) in the emergency department (ED) is challenging, with turnaround times exceeding the timeline for rapid diagnosis. We studied the usefulness of procalcitonin as a marker of BSI in 367 adults admitted to our ED with symptoms of systemic infection. Serum samples obtained at the same time as blood cultures were available from 295 patients. Procalcitonin levels were compared with blood culture results and other clinical data obtained during the ED visit. Procalcitonin levels of less than 0.1 ng/mL were considered negative; all other levels were considered positive. In 16 patients, there was evidence of BSI by blood culture, and 12 (75%) of 16 patients had a procalcitonin level of more than 0.1 ng/mL. In 186 (63.1%) of 295 samples, procalcitonin values were less than 0.1 ng/mL, and all were culture negative. With a calculated threshold of 0.1475 ng/mL for procalcitonin, sensitivity and specificity for the procalcitonin assay were 75% and 79%, respectively. The positive predictive value was 17% and the negative predictive value 98% compared with blood cultures. Procalcitonin is a useful marker to rule out sepsis and systemic inflammation in the ED.

Current management of bloodstream infections

Bloodstream infection (BSI) is a frequent complication of invasive infections. The presence of bacteremia has therapeutic and prognostic implications. Here we review recent changes in the epidemiology, diagnosis and treatment of BSI (excluding candidemia). The evidence of the impact of healthcare-association in many community-onset episodes and the increase in drug-resistant pathogens causing BSI in the community and hospitals is reviewed. The emergence of molecular methods as an alternative tool for the diagnosis of BSI and novel aspects of clinical management, particularly of some multidrug-resistant organisms. Several quality indicators related to the diagnosis and management of bacteremia in hospitals are proposed.

Additional value of procalcitonin for diagnosis of infection in patients with fever at the emergency department

OBJECTIVE

First, to determine whether procalcitonin (PCT) significantly adds diagnostic value in terms of sensitivity and specificity to a common set of markers of infection, including C-reactive protein (CRP), at the Emergency Department. Second, to create a simple scoring rule implementing PCT values. Third, to determine and compare associations of CRP and PCT with clinical outcomes.

DESIGN

The additional diagnostic value of PCT was determined using multiple logistic regression analysis. A score was developed to help distinguish patients with a culture-proven bacterial infection from patients not needing antibiotic treatment using 16 potential clinical and laboratory variables. The prognostic value of CRP and PCT was determined using Spearman's correlation and logistic regression.

SETTING

Emergency Department of a 310-bed teaching hospital.

PATIENTS

Patients between 18 and 85 years old presenting with fever to the Emergency Department.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 211 patients were studied (infection confirmed, n = 73; infection likely, n = 58; infection not excluded, n = 46; no infection, n = 34). CRP and chills were the strongest predictors for the diagnosis of bacterial infection. After addition of PCT to these parameters, model fit significantly improved (p = .003). The resulting scoring rule (score = 0.01 * CRP + 2 * chills + 1 * PCT) was characterized by an AUC value of 0.83 (sensitivity 79%; specificity of 71%), which was more accurate than physician judgment or SIRS (systemic inflammatory response syndrome). PCT levels were significantly associated with admission to a special care unit, duration of intravenous antibiotic use, total duration of antibiotic treatment, and length of hospital stay, whereas CRP was related only to the latter two variables.

CONCLUSIONS

These data suggest that PCT may be a valuable addition to currently used markers of infection for diagnosis of infection and prognosis in patients with fever at the Emergency Department.

Stratification of the severity of critically ill patients with classification trees

Background

Development of three classification trees (CT) based on the CART (Classification and Regression Trees), CHAID (Chi-Square Automatic Interaction Detection) and C4.5 methodologies for the calculation of probability of hospital mortality; the comparison of the results with the APACHE II, SAPS II and MPM II-24 scores, and with a model based on multiple logistic regression (LR).

Methods

Retrospective study of 2864 patients. Random partition (70:30) into a Development Set (DS) n = 1808 and Validation Set (VS) n = 808. Their properties of discrimination are compared with the ROC curve (AUC CI 95%), Percent of correct classification (PCC CI 95%); and the calibration with the Calibration Curve and the Standardized Mortality Ratio (SMR CI 95%).

Results

CTs are produced with a different selection of variables and decision rules: CART (5 variables and 8 decision rules), CHAID (7 variables and 15 rules) and C4.5 (6 variables and 10 rules). The common variables were: inotropic therapy, Glasgow, age, (A-a)O2 gradient and antecedent of chronic illness. In VS: all the models achieved acceptable discrimination with AUC above 0.7. CT: CART (0.75(0.71-0.81)), CHAID (0.76(0.72-0.79)) and C4.5 (0.76(0.73-0.80)). PCC: CART (72(69-75)), CHAID (72(69-75)) and C4.5 (76(73-79)). Calibration (SMR) better in the CT: CART (1.04(0.95-1.31)), CHAID (1.06(0.97-1.15) and C4.5 (1.08(0.98-1.16)).

Conclusion

With different methodologies of CTs, trees are generated with different selection of variables and decision rules. The CTs are easy to interpret, and they stratify the risk of hospital mortality. The CTs should be taken into account for the classification of the prognosis of critically ill patients.

PTX3 predicts severe disease in febrile patients at the emergency department

OBJECTIVES

The long pentraxin PTX3 is a promising marker of disease severity in severely ill patients. In order to identify patients warranting critical care as quickly as possible, we investigated the value of PTX3 as a biomarker for disease severity in patients presenting with fever at the emergency department.

METHODS

Levels of PTX3 were measured in 211 febrile patients at the emergency and the levels were linked to markers of disease severity including admittance to a special care unit, bloodstream infection and congestive heart failure.

RESULTS

In comparison to median baseline levels of 2.30 ng/ml (interquartile range 1.66-3.67 ng/ml), levels of PTX3 were significantly elevated in patients admitted to the intensive-/medium care unit (median value 44.4 ng/ml, interquartile range 13.6-105.9 ng/ml) and in patients referred to the ward (median value 14.2 ng/ml, interquartile range 7.01-25.1 ng/ml). In addition, PTX3 was associated with duration of hospital stay and acute congestive heart failure. The levels were predictive for bloodstream infection (AUC=0.71; 95% CI 0.62-0.81).

CONCLUSIONS

PTX3 may be a useful marker for differentiation of patients with severe disease in patients presenting with fever to the emergency department.

Clinical parameters predicting failure of empirical antibacterial therapy in early onset neonatal sepsis, identified by classification and regression tree analysis

BACKGROUND

About 10-20% of neonates with suspected or proven early onset sepsis (EOS) fail on the empiric antibiotic regimen of ampicillin or penicillin and gentamicin. We aimed to identify clinical and laboratory markers associated with empiric antibiotic treatment failure in neonates with suspected EOS.

METHODS

Maternal and early neonatal characteristics predicting failure of empiric antibiotic treatment were identified by univariate logistic regression analysis from a prospective database of 283 neonates admitted to neonatal intensive care unit within 72 hours of life and requiring antibiotic therapy with penicillin or ampicillin and gentamicin. Variables, identified as significant by univariate analysis, were entered into stepwise multiple logistic regression (MLR) analysis and classification and regression tree (CRT) analysis to develop a decision algorithm for clinical application. In order to ensure the earliest possible timing separate analysis for 24 and 72 hours of age was performed.

RESULTS

At 24 hours of age neonates with hypoglycaemia < or = 2.55 mmol/L together with CRP values > 1.35 mg/L or those with BW < or = 678 g had more than 30% likelihood of treatment failure. In normoglycaemic neonates with higher BW the best predictors of treatment failure at 24 hours were GA < or = 27 weeks and among those, with higher GA, WBC < or = 8.25 x 10(9) L(-1) together with platelet count < or = 143 x 10(9) L(-1). The algorithm allowed capture of 75% of treatment failure cases with a specificity of 89%. By 72 hours of age minimum platelet count < or = 94.5 x 10(9) L(-1) with need for vasoactive treatment or leukopaenia < or = 3.5 x 10(9) L(-1) or leukocytosis > 39.8 x 10(9) L(-1) or blood glucose < or = 1.65 mmol/L allowed capture of 81% of treatment failure cases with the specificity of 88%. The performance of MLR and CRT models was similar, except for higher specificity of the CRT at 72 h, compared to MLR analysis.

CONCLUSION

There is an identifiable group of neonates with high risk of EOS, likely to fail on conventional antibiotic therapy.

Circulating biomarkers as surrogates for bloodstream infections

The use of biomarkers provides a novel approach to diagnosing infection, its severity and treatment response. Biomarkers, especially procalcitonin and, to a lesser extent, C-reactive protein and interleukin 8, can improve the diagnostic and prognostic assessment of bloodstream infections. Both strengths and weaknesses of biomarkers must be recognized for rational and safe use in clinical settings. Cut-off ranges must be chosen within the specific clinical context. Ultrasensitive assays for procalcitonin, capable of measuring low levels in healthy individuals, may help to identify even 'subclinical' inflammatory states before the development of clinically evident sepsis. For immunocompromised patients, the use of biomarkers could lead to an earlier and more targeted antimicrobial therapy for patients at risk of sepsis, whereas those patients with viral illness or a non-infectious aetiology of inflammation who maintain low levels of procalcitonin over time can be withheld from antibiotic exposure. The time has arrived to move beyond the observational reporting of 'promising' biomarkers. Specific cut-off ranges must be proposed and intervention studies conducted to tackle the existing vicious cycle of diagnostic uncertainty, antibiotic overuse and emerging multi-resistance.

Biomarkers to improve diagnostic and prognostic accuracy in systemic infections

PURPOSE OF REVIEW

We review the advantages and drawbacks of biomarkers in the diagnostic and prognostic assessment of systemic infections.

RECENT FINDINGS

Since the signs and symptoms of severe infections can be ambiguous, biomarkers provide a more reliable tool in ascertaining the presence of a relevant bacterial infection, its severity and treatment response. Procalcitonin and, to a lesser extent, C-reactive protein and interleukin-8 can improve the diagnostic assessment of infections and guide antibiotic therapy. Promising prognostic biomarkers include cortisol, proadrenomedullin, copeptin and natriuretic peptides. The strengths and weaknesses of biomarkers must be recognized in order to use them rationally and safely. Cutoff ranges of biomarkers must be chosen according to the specific clinical context and they should be used as a complementary tool, to reinforce the clinical diagnostic workup. Biomarkers cannot determine the causative organisms and associated patterns of antibiotic susceptibility.

SUMMARY

If used in the proper setting, serial measurements of diagnostic biomarkers may allow treatments to be adjusted at an early stage in patients with severe infections. This may involve either intensifying treatment when infection levels stay high or avoiding unnecessary prolonged courses of antibiotics when levels rapidly decrease, thereby improving the allocation of healthcare resources.