The potential impact of biomarker-guided triage decisions for patients with urinary tract infections

MR-Proadrenomedullin as biomarker of renal damage in urinary tract infection in children

Background

Midregional-proadrenomedullin (MR-proADM) is a useful prognostic peptide in severe infectious pathologies in the adult population. However, there are no studies that analyze its utility in febrile urinary tract infection (fUTI) in children. An accurate biomarker would provide an early detection of patients with kidney damage, avoiding other invasive tests like renal scintigraphy scans. Our objective is to study the usefulness of MR-proADM as a biomarker of acute and chronic renal parenchymal damage in fUTI within the pediatric population.

Methods

A prospective cohort study was conducted in pediatric patients with fUTI between January 2015 and December 2018. Plasma and urine MR-proADM levels were measured at admission in addition to other laboratory parameters. After confirmation of fUTI, renal scintigraphy scans were performed during the acute and follow-up stages. A descriptive study has been carried out and sensitivity, specificity and ROC curves for MR-proADM, C-reactive protein, and procalcitonin were calculated.

Results

62 pediatric patients (34 female) were enrolled. Scintigraphy showed acute pyelonephritis in 35 patients (56.5%). Of those patients, the median of plasmatic MR-proADM (P-MR-proADM) showed no differences compared to patients without pyelonephritis. 7 patients (11.3%) developed renal scars (RS). Their median P-MR-proADM levels were 1.07 nmol/L (IQR 0.66–1.59), while in patients without RS were 0.48 nmol/L (0.43–0.63) (p < 0.01). The AUC in this case was 0.92 (95% CI 0.77–0.99). We established an optimal cut-off point at 0.66 nmol/L with sensitivity 83.3% and specificity 81.8%.

Conclusion

MR-ProADM has demonstrated a poor ability to diagnose pyelonephritis in pediatric patients with fUTI. However, P-MR-proADM proved to be a very reliable biomarker for RS prediction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02765-2.

Midregional proadrenomedullin safely reduces hospitalization in a low severity cohort with infections in the ED: a randomized controlled multi-centre interventional pilot study

INTRODUCTION

The midregional fragment of proadrenomedullin (MR-proADM) is known to provide accurate short-, mid- and long term prognostic information in the triage and multi-dimensional risk assessment of patients in the emergency department (ED). In two independent observational cohorts MR-proADM values identified low disease severity patients without risk of disease progression in the ED with no 28 days mortality that wouldn´t require hospitalization. In this interventional study we want to show that the combination of an MR-proADM algorithm with clinical assessment is able to identify low risk patients not requiring hospitalization to safely reduce the number of hospital admissions.

METHODS

A randomized-controlled interventional multicenter study in 4 EDs in Spain. The study protocol was approved by Ethics Committees. Control arm patients received Standard Care. MR-proADM guided arm patients with low MR-proADM value (≤0.87 nmol/L) were treated as out-patients, with high MR-proADM value (>0.87 nmol/L) were hospitalized. The hospitalization rate was compared between the study arms.

RESULTS

Two hundred patients with suspicion of infection were enrolled. In the MR-proADM guided arm the hospital admission rate in the intention-to-treat (ITT) population was 17% lower than in the control arm (40.6% vs. 57.6%, p=0.024) and 20% lower in the per protocol (PP) population (37.2% vs. 57.6%, p=0.009). No deaths of out-patients and no significant difference for the safety endpoints readmission and representation rates were observed. The readmission rate was only slightly higher in the MR-proADM guided arm compared to the control arm (PP population: at 14 days 9.3% vs. 7.1%, difference 2.1% (95% CI: -11.0% to 15.2%); and at 28 days 11.1% vs. 9.5%, difference 1.6% (95% CI: -12.2% to 15.4%)). The rate of 28 days representation was slightly lower in the MR-proADM guided arm compared to the control arm (20.4% vs. 26.2%, difference -5.8% (95% CI: -25.0% to 13.4%); PP population).

CONCLUSIONS

Implementing a MR-proADM algorithm optimizes ED workflows efficiently and sustainably. Hospitals can highly benefit from a reduced rate of hospitalizations by 20% using MR-proADM. The safety in the MR-proADM guided study arm was similar to the Standard Care arm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT03770533.

Combination of the National Early Warning Score (NEWS) and inflammatory biomarkers for early risk stratification in emergency department patients: results of a multinational, observational study

OBJECTIVES

The National Early Warning Score (NEWS) helps to estimate mortality risk in emergency department (ED) patients. This study aimed to investigate whether the prognostic value of the NEWS at ED admission could be further improved by adding inflammatory blood markers (ie, white cell count (WCC), procalcitonin (PCT) and midregional-proadrenomedullin (MR-proADM).

DESIGN

Secondary analysis of a multinational, observational study (TRIAGE study, March 2013-October 2014).

SETTING

Three tertiary care centres in France, Switzerland and the USA.

PARTICIPANTS

A total of 1303 adult medical patients with complete NEWS data seeking ED care were included in the final analysis. NEWS was calculated retrospectively based on admission data.

MAIN OUTCOME MEASURES

The primary outcome was all-cause 30-day mortality. Secondary outcome was intensive care unit (ICU) admission. We used multivariate regression analyses to investigate associations of NEWS and blood markers with outcomes and area under the receiver operating curve (AUC) as a measure of discrimination.

RESULTS

Of the 1303 included patients, 54 (4.1%) died within 30 days. The NEWS alone showed fair prognostic accuracy for all-cause 30-day mortality (AUC 0.73), with a multivariate adjusted OR of 1.26 (95% CI 1.13 to 1.40, p<0.001). The AUCs for the prediction of mortality using the inflammatory markers WCC, PCT and MR-proADM were 0.64, 0.71 and 0.78, respectively. Combining NEWS with all three blood markers or only with MR-proADM clearly improved discrimination with an AUC of 0.82 (p=0.002). Combining the three inflammatory markers with NEWS improved prediction of ICU admission (AUC 0.70vs0.65 when using NEWS alone, p=0.006).

CONCLUSION

NEWS is helpful in risk stratification of ED patients and can be further improved by the addition of inflammatory blood markers. Future studies should investigate whether risk stratification by NEWS in addition to biomarkers improve site-of-care decision in this patient population.

TRIAL REGISTRATION NUMBER

NCT01768494; Post-results.

Biomarker guided triage can reduce hospitalization rate in community acquired febrile urinary tract infection

OBJECTIVES

Febrile urinary tract infections (fUTI) can often be treated safely with oral antimicrobials in an outpatient setting. However, a minority of patients develop complications that may progress into septic shock. An accurate assessment of disease severity upon emergency department (ED) presentation is therefore crucial in order to guide the most appropriate triage and treatment decisions.

METHODS

Consecutive patients were enrolled with presumptive fUTI across 7 EDs in the Netherlands. The biomarkers mid-regional proadrenomedullin (MR-proADM), procalcitonin (PCT), C-reactive protein (CRP), and a clinical score (PRACTICE), were compared in their ability to predict a clinically severe course of fUTI, initial hospital admission and subsequent readmission using area under the receiver operating characteristic (AUROC) curves.

RESULTS

Biomarker concentrations were measured in 313 patients, with 259 (83%) hospitalized upon ED presentation, and 54 (17%) treated as outpatients. Of these outpatients, 12 (22%) were later hospitalized. MR-proADM had the highest diagnostic accuracy for predicting a complicated fUTI (AUROC [95% CI]: 0.86 [0.79-0.92]), followed by PCT (AUROC [95% CI]: 0.69 [0.58-0.80]). MR-proADM concentrations were unique in being significantly elevated in patients directly admitted and in outpatients requiring subsequent hospitalization, compared to those completing treatment at home. A virtual triage algorithm with an MR-proADM cut-off of 0.80  nmol/L resulted in a hospitalization rate of 66%, with only 2% secondary admissions.

CONCLUSION

MR-proADM could accurately predict a severe course in patients with fUTI, and identify greater patient numbers who could be safely managed as outpatients. An initial assessment on ED presentation may focus resources to patients with highest disease severities.

Comparison of computed tomography findings between bacteremic and non-bacteremic acute pyelonephritis due to Escherichia coli

AIM: To identify computed tomography (CT) findings that are associated with the presence of bacteremia in patients with acute pyelonephritis (APN) due to Escherichia coli (E. coli).

METHODS: The clinical data and contrast-enhanced CT findings of 128 patients who were diagnosed with APN due to E. coli and showed renal abnormality on contrast-enhanced CT between January 2003 and November 2013 were retrospectively reviewed. The patients were divided into two groups according to the presence of bacteremia: The bacteremia group and the non-bacteremia group. The abnormality on contrast-enhanced CT were categorized into 5 renal and 4 extrarenal CT findings and compared between the two groups using the χ² test and multivariate logistic regression.

RESULTS: Among the 128 patients, 34 patients (26.6%) were classified into the bacteremia group and 94 patients (73.4%) into the non-bacteremia group. There was no statistically significant difference in gender between the two groups (P = 0.09), but the age of the patients in the bacteremia group was higher than that of the patients in the non-bacteremia group (P < 0.01). Compared to the non-bacteremia group, 1 renal CT finding such as urothelial thickening and 3 extrarenal CT findings such as diffuse peritoneal thickening, cystitis and pulmonary congestion were more frequently observed in the bacteremia group with statistical significance. The logistic regression analysis revealed that CT findings, including urothelial thickening, diffuse peritoneal thickening, cystitis and pulmonary congestion were suggested as the predictive CT findings of bacteremic APN.

CONCLUSION: On CT, urothelial thickening, diffuse peritoneal thickening, cystitis, and pulmonary congestion are more frequently observed in patients with bacteremic APN due to E. coli.

Adrenomedullin for Risk Stratification of Emergency Patients With Nonspecific Complaints: An Interventional Multicenter Pilot Study

Patients with nonspecific complaints (NSC) presenting to the emergency department (ED) are at risk of life-threatening conditions. New stress biomarkers such as the midregional portion of adrenomedullin (MR-proADM) promise to support decision-making. This study tested the following hypotheses: biomarker-assisted disposition of patients with NSC will not increase mortality. Second, discharge from the ED will increase if clinical risk assessment is combined with low MR-proADM levels. Third, inappropriate disposition to a lower level of care will decrease, if clinical assessment is combined with high MR-proADM levels, and fourth that this algorithm is feasible in the ED setting. Prospective, multicenter, randomized, controlled interventional feasibility study with a 30-day follow-up, including patients with NSC. Patients were randomly assigned to either the standard group (decision-making solely based on clinical assessment) or the Novum group (biomarker-assisted). Regarding disposition, patients were assigned to 1 of 3 risk classes: high-risk (admission to hospital), intermediate risk (community geriatric hospital), and low-risk patients (discharge). In the Novum group, in addition to clinical risk assessment, the information of the MR-proADM level was used. Unless there were overruling criteria, patients were transferred or discharged according to the risk assessment. Primary endpoint was 30-day mortality. Secondary endpoints were comparisons of patient disposition and related mortality rates, ED, and hospital length of stay and readmission. The final study cohort consisted of 398 patients (210 in the Standard group and 188 in the Novum group). Overruling, that is, disposition not according to the result of the proposed algorithm occurred in 51 cases. Baseline characteristics between Standard and Novum groups were similar. The mortality rate in the Novum group was 4.3%, as compared to the Standard group mortality of 6.2%, which was not significantly different (intention-to treat analysis). This was confirmed by the perprotocol analysis as well as by sensitivity analysis. For the secondary endpoints, no significant differences were detected. Biomarker-assisted disposition is safe in patients with NSC. Discharge rates did not increase. Feasibility could only partly be shown due to an unexpectedly high overruling rate. Inappropriate disposition to lower levels of care did not change. ClinicalTrials. gov Identifier: NCT00920491.

Febrile urinary tract infection in the emergency room

PURPOSE OF REVIEW

To review the recent advances in the diagnostic and therapeutic approach to adults presenting with febrile urinary tract infection (UTI) in the emergency department (ED).

RECENT FINDINGS

Recent research suggests overdiagnosis and therefore overtreatment of UTI in the ED, especially in the elderly. Antimicrobial pretreatment, an indwelling catheter, and malignancy are independent risk factors for bacteremia with uropathogens that cannot be cultured from urine. A simple clinical prediction rule can predict clinically relevant radiologic findings in patients with invasive UTI. Procalcitonin is a marker for bacteremia; pro-adrenomedullin predicts a complicated course and 30-day mortality in complicated UTI. Several reports have identified the risk factors for resistant uropathogens in community-acquired febrile UTI. Adherence to the guidelines and early culture-guided intravenous-to-oral switch reduces the length of hospitalization.

SUMMARY

An effective strategy is needed to improve the diagnosis of UTIs in acute care. Further research regarding biomarker-guided triage might improve the management of patients with febrile UTI. Future efforts should be directed toward the improvement of adherence to UTI treatment guidelines.

Predictive factors of bacteremia in patients with febrile urinary tract infection: an experience at a tertiary care center

PURPOSE

To investigate the clinical features in adult patients with febrile urinary tract infection (UTI) who visited the emergency department (ED) and to determine the predictive factors of bacteremia among the initial presenting clinical features.

METHODS

This retrospective cohort study was conducted at the ED of a tertiary hospital in Korea from 1 January 2012 to 31 December 2012. All adult patients who were diagnosed with febrile UTI and for whom data on blood and urine cultures were available were included in the study. Clinical examinations and laboratory tests were performed at the initial presentation.

RESULTS

A total of the 325 patients with febrile UTI (median age: 60 years) were included for analysis, of whom 82 % were female. Bacteremia was detected in 106 of the 325 patients (32.6 %), with Escherichia coli the most frequent pathogen detected (59.7 % of cases). Between the bacteremic and non-bacteremic groups, there was significant difference in age (67 vs. 57 years, respectively), flank pain (16 vs. 7.8 %), suprapubic discomfort (0 vs. 4.6 %), body temperature (38.8 vs. 38.3 °C), respiratory rate (21 vs. 20/min), platelet count (170 vs. 186 × 10(3)/μL), C-reactive protein (10.2 vs. 8.3 mg/dL), and procalcitonin (1.5 vs. 0.3 ng/mL) (P < 0.05 for all). In the multivariate logistic regression analysis, age [odds ratio (OR) 1.03; 95 % confidence interval (CI) 1.01-1.05], systolic blood pressure of <90 mmHg (OR 3.27; 95 % CI 1.13-9.45), body temperature of >39 °C (OR 4.26; 95 % CI 2.28-7.96), and procalcitonin level of >0.5 ng/dL (OR 2.03; 95 % CI 1.07-3.86) were significantly associated with bacteremia.

CONCLUSION

Among our adult patients with febrile UTI, age, systolic blood pressure, body temperature, and procalcitonin were significantly associated with bacteremia. We therefore suggest that these factors should be considered when deciding upon treatment options for febrile UTI patients at the ED.

Effectiveness of Proadrenomedullin Enhanced CURB65 Score Algorithm in Patients with Community-Acquired Pneumonia in "Real Life", an Observational Quality Control Survey

BACKGROUND

An intervention trial found a trend for shorter length of stay (LOS) in patients with community-acquired pneumonia (CAP) when the CURB65 score was combined with the prognostic biomarker proadrenomedullin (ProADM) (CURB65-A). However, the efficacy and safety of CURB65-A in real life situations remains unclear.

METHODS

From September, 2011, until April, 2012, we performed a post-study prospective observational quality control survey at the cantonal Hospital of Aarau, Switzerland of consecutive adults with CAP. The primary endpoint was length of stay (LOS) during the index hospitalization and within 30 days. We compared the results with two well-defined historic cohorts of CAP patients hospitalized in the same hospital with the use of multivariate regression, namely 83 patients in the observation study without ProADM (OPTIMA I) and the 169 patients in the intervention study (OPTIMA II RCT).

RESULTS

A total of 89 patients with confirmed CAP were included. As compared to patients with CURB65 only observed in the OPTIMA I study, adjusted regression analysis showed a significant shorter initial LOS (7.5 vs. 10.4 days; -2.32; 95% CI, -4.51 to -0.13; p = 0.04) when CURB65-A was used in clinical routine. No significant differences were found for LOS within 30 days. There were no significant differences in safety outcomes in regard to mortality and ICU admission between the cohorts.

CONCLUSION

This post-study survey provides evidence that the use of ProADM in combination with CURB65 (CURB65-A) in "real life" situations reduces initial LOS compared to the CURB65 score alone without apparent negative effects on patient safety.

Procalcitonin, pyuria and proadrenomedullin in the management of urinary tract infections--'triple p in uti': study protocol for a randomized controlled trial

Background

Urinary tract infections (UTIs) are among the most common infectious diseases and drivers of antibiotic use and in-hospital days. A reduction of antibiotic use potentially lowers the risk of antibiotic resistance. An early and adequate risk assessment combining medical, biopsychosocial and functional risk scores has the potential to optimize site-of-care decisions and thus allocation of limited health-care resources. The aim of this factorial design study is twofold: first, for Intervention A, it investigates antibiotic exposure of patients treated with a protocol based on the type of UTI, procalcitonin (PCT) and pyuria. Second, for Intervention B, it investigates the usefulness of the prognostic biomarker proadrenomedullin (ProADM) integrated into an interdisciplinary assessment bundle for site-of-care decisions.

Methods and design

This randomized controlled open-label trial has a factorial design (2 × 2). Randomization of patients will be based on a pre-specified computer-generated randomization list and independent for the two interventions. Adults with UTI presenting to the emergency department (ED) will be screened and enrolled after providing informed consent.

For our first Intervention (A), we developed a protocol based on previous observational research to recommend initiation and duration of antibiotic use based on the clinical presentation of UTI, pyuria and PCT levels. For our second intervention (B), an algorithm was developed to support site-of care decisions based on the prognostic marker ProADM and distinct nursing factors on days 1 and 3. Both interventions will be compared with a control group conforming to the guidelines.

The primary endpoints for the two interventions will be: (A) overall exposure to antibiotics and (B) length of physician-led hospitalization within a follow-up of 30 days. Endpoints are assessed at discharge from hospital, and 30 and 90 days after admission. We plan to screen 300 patients and enroll 250 for an anticipated estimated loss of follow-up of 20%. This will provide adequate power for the two interventions.

Discussion

This trial investigates two strategies for improved individualized medical care in patients with UTI. The minimally effective duration of antibiotic therapy is not known for UTIs, which is important for reducing the selection pressure for antibiotic resistance, costs and drug-related side effects. Triage decisions must be improved to reflect the true medical, biopsychosocial and functional risks in order to allocate patients to the most appropriate care setting and reduce hospital-acquired disability.

Trial registration

Trial registration number: ISRCTN13663741