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

Lung ultrasound and procalcitonin, improving antibiotic management and avoiding radiation exposure in pediatric critical patients with bacterial pneumonia: a randomized clinical trial

BACKGROUND

Pneumonia is a major public health problem with an impact on morbidity and mortality. Its management still represents a challenge. The aim was to determine whether a new diagnostic algorithm combining lung ultrasound (LUS) and procalcitonin (PCT) improved pneumonia management regarding antibiotic use, radiation exposure, and associated costs, in critically ill pediatric patients with suspected bacterial pneumonia (BP).

METHODS

Randomized, blinded, comparative effectiveness clinical trial. Children < 18y with suspected BP admitted to the PICU from September 2017 to December 2019, were included. PCT was determined at admission. Patients were randomized into the experimental group (EG) and control group (CG) if LUS or chest X-ray (CXR) were done as the first image test, respectively. Patients were classified: 1.LUS/CXR not suggestive of BP and PCT < 1 ng/mL, no antibiotics were recommended; 2.LUS/CXR suggestive of BP, regardless of the PCT value, antibiotics were recommended; 3.LUS/CXR not suggestive of BP and PCT > 1 ng/mL, antibiotics were recommended.

RESULTS

194 children were enrolled, 113 (58.2%) females, median age of 134 (IQR 39-554) days. 96 randomized into EG and 98 into CG. 1. In 75/194 patients the image test was not suggestive of BP with PCT < 1 ng/ml; 29/52 in the EG and 11/23 in the CG did not receive antibiotics. 2. In 101 patients, the image was suggestive of BP; 34/34 in the EG and 57/67 in the CG received antibiotics. Statistically significant differences between groups were observed when PCT resulted < 1 ng/ml (p = 0.01). 3. In 18 patients the image test was not suggestive of BP but PCT resulted > 1 ng/ml, all of them received antibiotics. A total of 0.035 mSv radiation/patient was eluded. A reduction of 77% CXR/patient was observed. LUS did not significantly increase costs.

CONCLUSIONS

Combination of LUS and PCT showed no risk of mistreating BP, avoided radiation and did not increase costs. The algorithm could be a reliable tool for improving pneumonia management.

CLINICAL TRIAL REGISTRATION

NCT04217980.

AACC Guidance Document on the Clinical Use of Procalcitonin

BACKGROUND

Procalcitonin (PCT), a peptide precursor of the hormone calcitonin, is a biomarker whose serum concentrations are elevated in response to systemic inflammation caused by bacterial infection and sepsis. Clinical adoption of PCT in the United States has only recently gained traction with an increasing number of Food and Drug Administration-approved assays and expanded indications for use. There is interest in the use of PCT as an outcomes predictor as well as an antibiotic stewardship tool. However, PCT has limitations in specificity, and conclusions surrounding its utility have been mixed. Further, there is a lack of consensus regarding appropriate timing of measurements and interpretation of results. There is also a lack of method harmonization for PCT assays, and questions remain regarding whether the same clinical decision points may be used across different methods.

CONTENT

This guidance document aims to address key questions related to the use of PCT to manage adult, pediatric, and neonatal patients with suspected sepsis and/or bacterial infections, particularly respiratory infections. The document explores the evidence for PCT utility for antimicrobial therapy decisions and outcomes prediction. Additionally, the document discusses analytical and preanalytical considerations for PCT analysis and confounding factors that may affect the interpretation of PCT results.

SUMMARY

While PCT has been studied widely in various clinical settings, there is considerable variability in study designs and study populations. Evidence to support the use of PCT to guide antibiotic cessation is compelling in the critically ill and in some lower respiratory tract infections but is lacking in other clinical scenarios, and evidence is also limited in the pediatric and neonatal populations. Interpretation of PCT results requires guidance from multidisciplinary care teams of clinicians, pharmacists, and clinical laboratorians.

Antimicrobial Stewardship Programs in PICU Settings: A Systematic Review

OBJECTIVES

Development of antimicrobial stewardship programs (ASPs) is strategy for prevention and management of emergence of antimicrobial-resistant organisms. In this study, we systematically reviewed the literature on antimicrobial stewardship interventions in PICUs and analyzed approaches, structure, implementation, and outcomes of the ASPs.

DATA SOURCES

PubMed and Scopus databases were systematically searched for studies published from January 1, 2007, to December 31, 2020, reporting interventions on judicious use of antimicrobials in PICUs (last search performed February 28, 2021).

DATA SELECTION

Studies that evaluated an intervention in a PICU setting or both in PICU and other settings and reported separate results for PICU were eligible for full-text review. Studies that had implemented stewardship in the entire hospital, including the PICU, but without presenting dedicated PICU data were excluded from the analysis.

DATA EXTRACTION

The strategy of intervention, structure of ASP team, implementation, and outcomes were assessed with a checklist tool for all studies included in the analysis. Risk of bias was assessed with the Cochrane Risk-of-Bias in Nonrandomized studies of Interventions tool.

DATA SYNTHESIS

Thirteen articles were found: 11 that applied ASP in PICUs, and two at hospital level. All PICU-dedicated ASPs applied a multimodal intervention combining strategies simultaneously; audit with feedback (6/11) and facility-specific clinical practice guidelines (7/11) were the most common strategies. A multidisciplinary team was formulated in all ASPs except for three biomarker-based interventions. Six of 11 studies included techniques to enhance behavior change and one implemented a behavior-based intervention. Antibiotic consumption was evaluated in all ASPs, cost in three of 11, antibiotic resistance in one of 11, length of hospitalization in six of 11, and mortality in eight of 11. All hospital-wide ASPs used audit with feedback in addition to facility-specific clinical practice guidelines and assessed antimicrobial consumption, expenditures, length of stay, and mortality.

CONCLUSIONS

The prevalence of ASPs in PICUs is limited, and few programs follow all of the currently available recommendations.

An algorithm combining procalcitonin and lung ultrasound improves the diagnosis of bacterial pneumonia in critically ill children: The PROLUSP study, a randomized clinical trial

BACKGROUND

Lung ultrasound (LUS) and procalcitonin (PCT) are independently used to improve accuracy when diagnosing lung infections. The aim of the study was to evaluate the accuracy of a new algorithm combining LUS and PCT for the diagnosis of bacterial pneumonia.

METHODS

Randomized, blinded, comparative effectiveness clinical trial. Children <18 years old with suspected pneumonia admitted to pediatric intensive care unit were included, and randomized into experimental group (EG) or control group (CG) if LUS or chest X-Ray (CXR) were done as the first pulmonary image, respectively. PCT was determined. In patients with bacterial pneumonia, sensitivity, specificity, and predictive values of LUS, CXR, and of both combined with PCT were analyzed and compared. Concordance between the final diagnosis and the diagnosis concluded through the imaging test was assessed.

RESULTS

A total of 194 children, with a median age of 134 (interquartile range [IQR]: 39-554) days, were enrolled, 96 randomized into the EG and 98 into the CG. Bacterial pneumonia was diagnosed in 97 patients. Sensitivity and specificity for bacterial pneumonia diagnosis were 78% (95% confidence interval [CI]: 70-85) and 98% (95% CI: 93-99) for LUS, 85% (95% CI: 78-90) and 53% (95% CI: 43-62) for CXR, 90% (95% CI: 83-94) and 85% (95% CI: 76-91) when combining LUS and PCT, and 95% (95% CI: 90-98) and 41% (95% CI: 31-52) when combining CXR and PCT. The positive predictive value for LUS and PCT was 88% (95% C:I 79%-93%) versus 68% (95% CI: 60-75) for CXR and PCT. The concordance between the final diagnosis and LUS had a kappa value of 0.69 (95% CI: 0.62-0.75) versus 0.34 (95% CI: 0.21-0.45) for CXR, (p < 0.001).

CONCLUSIONS

The combination of LUS and PCT presented a better accuracy for bacterial pneumonia diagnosis than combining CXR and PCT. Therefore, its implementation could be a reliable tool for pneumonia diagnosis in critically ill children.

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

Objectives

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

Study design

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

Results

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

Conclusions

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

Perioperative management after elective cardiac surgery: the predictive value of procalcitonin for infective and noninfective complications

Objective: Procalcitonin (PCT) has been associated with adverse outcomes after cardiac surgery. Nevertheless, there is no consensus on thresholds and timing of PCT measurement to predict adverse outcomes. Materials & methods: A total of 960 patients undergoing elective cardiac surgery were retrospectively evaluated. PCT levels were measured from the first to the seventh postoperative day (POD). The onset of complications was recorded. Results: Complications occurred in 421 (44%) patients. PCT on the third POD was associated with the occurrence of any kind of complications (odds ratio: 1.06; p: 0.037), and noninfectious complications (odds ratio: 1.05; p: 0.035), after adjusting. PCT above the median value at the third POD (>0.33 μg/l) predicted postoperative complications (incidence rate ratio: 1.13; p = 0.035). Conclusion: PCT seems to predict postoperative complications in cardiac surgery. The determination at the third POD yields the greatest sensitivity and specificity.

Use of procalcitonin and C-reactive protein in the diagnosis of bacterial infection in infants with severe bronchiolitis

The objective was to evaluate the use of procalcitonin (PCT) and C-reactive protein (CRP) for the diagnosis of bacterial infection in bronchiolitis patients. A prospective, single-centre, descriptive, and comparative observational study was carried out on patients with severe bronchiolitis admitted to the paediatric intensive care unit (PICU), from January 2011 to July 2017. Two cohorts were compared: patients with invasive bacterial infection (IBI) and patients with no bacterial infection (NBI). We included 675 patients, 399 of whom were males (59.1%), with median age of 47 days (IQR 25-100.3). Of them, 181 patients were diagnosed with IBI (26.8%). Seventy-two had sepsis (10.7%), 106 had pneumonia (15.7%), and 41 had a urinary tract infection (6.1%). PCT and CRP values were significantly higher in patients with IBI. ROC curves compared the ability of PCT and CRP to diagnose IBI at admission, 24 h, and 48 h. PCT showed a better AUC for diagnosing IBI, with statistically significant differences at all time points (p < 0.001). The best PCT cut-off for IBI diagnosis at admission was 1.4 ng/mL, with a sensitivity of 69% (95% CI 58.4-74.9) and a specificity of 91% (95% CI 88.1-92.5). Procalcitonin showed a better AUC for diagnosing both sepsis and pneumonia, which makes it an excellent predictor.Conclusion: We present PCT as a novel test in comparison with the traditional CRP screening test to discern which bronchiolitis patients have IBI. We highlight the importance of PCT for the diagnosis of pneumonia and sepsis, as it proved to be more sensitive and specific than CRP, with statistically significant differences. What is Known: • Bronchiolitis should be treated with antibiotics only when a bacterial infection is present. • The rate of antibiotic prescription in severe bronchiolitis is extremely high, so diagnostic tools are needed. What is New: • PCT is a good biomarker to discern which bronchiolitis patients have IBI, specially for pneumonia and sepsis diagnoses. It is more sensitive and specific than CRP, with statistically significant differences. • Implementation of PCT cut-off values may prevent unnecessary antibiotic use.

Procalcitonin and lung ultrasound algorithm to diagnose severe pneumonia in critical paediatric patients (PROLUSP study). A randomised clinical trial

Background

Lung ultrasound (LUS) in combination with a biomarker has not yet been studied. We propose a clinical trial where the primary aims are: 1. To assess whether an algorithm with LUS and procalcitonin (PCT) may be useful for diagnosing bacterial pneumonia; 2. To analyse the sensitivity and specificity of LUS vs chest X-ray (CXR).

Methods/design

A 3-year clinical trial. Inclusion criteria: children younger than 18 years old with suspected pneumonia in a Paediatric Intensive Care Unit. Patients will be randomised into two groups: Experimental Group: LUS will be performed as first lung image. Control Group: CXR will be performed as first pulmonary image. Patients will be classified according to the image and the PCT: a) PCT < 1 ng/mL and LUS/CXR are not suggestive of bacterial pneumonia (BN), no antibiotic will be prescribed; b) LUS/CXR are suggestive of BN, regardless of the PCT, antibiotic therapy is recommended; c) LUS/CXR is not suggestive of BN and PCT > 1 ng/mL, antibiotic therapy is recommended.

Conclusion

This algorithm will help us to diagnose bacterial pneumonia and to prescribe the correct antibiotic treatment. A reduction of antibiotics per patient, of the treatment length, and of the exposure to ionizing radiation and in costs is expected.

Trial registration

NCT04217980.