Utility of initial procalcitonin values to predict urinary tract infection

Diagnostic accuracy of procalcitonin for bacterial infection in the Emergency Department: a systematic review

INTRODUCTION AND OBJECTIVE

The care of patients with a suspected infectious process in hospital emergency departments (ED) accounts for 15%-35% of all daily care in these healthcare areas in Spain and Latin America. The early and adequate administration of antibiotic treatment (AB) and the immediate making of other diagnostic-therapeutic decisions have a direct impact on the survival of patients with severe bacterial infection. The main objective of this systematic review is to investigate the diagnostic accuracy of PCT to predict bacterial infection in adult patients treated with clinical suspicion of infection in the ED, as well as to analyze whether the different studies manage to identify a specific value of PCT as the most relevant from the diagnostic point of view of clinical decision that can be recommended for decision making in ED.

METHOD

A systematic review is carried out following the PRISMA regulations in the database of PubMed, Web of Science, EMBASE, Lilacs, Cochrane, Epistemonikos, Tripdatabase and ClinicalTrials.gov from January 2005 to May 31, 2023 without language restriction and using a combination of MESH terms: "Procalcitonin", "Infection/Bacterial Infection/Sepsis", "Emergencies/Emergency/Emergency Department", "Adults" and "Diagnostic". Observational cohort studies (diagnostic performance analyses) were included. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the method used and the risk of bias of the included articles. Observational cohort studies were included. No meta-analysis techniques were performed, but results were compared narratively.

RESULTS

A total of 1,323 articles were identified, of which 21 that met the inclusion criteria were finally analyzed. The studies include 10,333 patients with 4,856 bacterial infections (47%). Eight studies were rated as high, 9 as moderate, and 4 as low. The AUC-ROC of all studies ranges from 0.68 (95% CI: 0.61-0.72) to 0.99 (95% CI: 0.98-1). The value of PCT 0.2-0.3 ng/ml is the most used and proposed in up to twelve of the works included in this review whose average estimated performance is an AUC-ROC of 0.79. If only the results of the 5 high-quality studies using a cut-off point of 0.2-0.3 ng/ml PCT are taken into account, the estimated mean AUC-COR result is 0.78 with Se:69 % and Es:76%.

CONCLUSIONS

PCT has considerable diagnostic accuracy for bacterial infection in patients treated in ED for different infectious processes. The cut-off point of 0.25 (0.2-0.3) ng/ml has been positioned as the most appropriate to predict the existence of bacterial infection and can be used to help reasonably rule it out.

Challenges of antimicrobial stewardship among older adults

Older adults hospitalized in internal medicine wards or long-term care facilities (LTCF) are progressively increasing. Older adults with multimorbidity are more susceptible to infections, as well as to more vulnerable to adverse effects (and interactions) of antibiotics, resulting in a need for effective and safer strategies for antimicrobial stewardship (ASM), both in hospitalization wards and long-term care facilities. Studies on antimicrobial stewardship in older patients are scarce and guidelines are required. Given the peculiarities of the optimization of antimicrobial prescription in individual older adults for common infections, tactics to overcome barriers need an update. The use of rapid diagnosis tests, biomarkers, de-escalation and switching from intravenous to oral/subcutaneous therapy strategies are examples of successful AMS interventions. AMS interventions are associated with reduced side effects, lower mortality, shorter hospital stays, and reduced costs. The proposed AMS framework in LTCF should focus on five domains: strategic vision, team, interventions, patient-centred care and awareness. Internists can partner with geriatrists, pharmacists and infectious disease specialists to address barriers and to improve patient care.

A prospective observational study on the efficacy of procalcitonin as a diagnostic test to exclude lower urinary tract infection and to minimize antibiotic overuse

Background

Urinary tract infection (UTI) stands out as the third-most common infection following gastrointestinal and respiratory tract infections. Over the past decade, the biomarker procalcitonin (PCT) has gained prominence to facilitate the detection of bacterial infections and reduce excessive antibiotic exposure.

Objective

The objective of this study was to mitigate the overuse of antibiotics, by promoting the noninitiation or early discontinuation of empirical antibiotics, which would significantly help minimize the proliferation of multidrug-resistant bacteria.

Methodology

A prospective observational study was carried out at the tertiary care center in the Department of General Medicine of Kalinga Institute of Medical Sciences, Bhubaneswar, involving 200 patients with symptoms of lower UTI such as increased frequency, urgency, burning micturition, retention, and suprapubic tenderness with or without positive urinalysis. Detailed demographic profiles along with symptoms at the time of admission were recorded in a pretested structured format. To determine a positive diagnosis of UTI, signs and symptoms of UTI with or without urinary cultures were tested. The PCT level was estimated using enhanced chemiluminescence technique. Other routine tests such as complete blood count, renal function test, liver function test, urine routine microscopy, culture, chest X-ray, and ultrasonography abdomen pelvis were done and recorded. All patients, who had an initial serum PCT level of < 0.5 ng/mL, were kept under observation with only conservative and symptomatic treatments. Patients were further reviewed for improvement in symptoms and repeat urine microscopy. All patients, who had an initial serum PCT level of > 0.5 ng/mL, were initiated with antibiotics as per the culture and sensitivity reports. Patients were followed up for improvement in symptoms with reports of repeated urinalysis.

Results

Our study reported the fact that 9.5% of the patients with initial serum PCT ≥ 0.5 ng/mL showed no improvement in symptoms despite starting antibiotics while significantly higher number of symptomatic patients (60%) with initial serum PCT < 0.5 ng/ml showed improvement in symptoms with conservative treatment without antibiotics.

Conclusion

A lower PCT level rules out bacterial invasion and thus can be used as a novel marker in antibiotic stewardship.

Urinary tract infections: a review of the current diagnostics landscape

Urinary tract infections are the most common bacterial infections worldwide. Infections can range from mild, recurrent (rUTI) to complicated (cUTIs), and are predominantly caused by uropathogenic Escherichia coli (UPEC). Antibiotic therapy is important to tackle infection; however, with the continued emergence of antibiotic resistance there is an urgent need to monitor the use of effective antibiotics through better stewardship measures. Currently, clinical diagnosis of UTIs relies on empiric methods supported by laboratory testing including cellular analysis (of both human and bacterial cells), dipstick analysis and phenotypic culture. Therefore, development of novel, sensitive and specific diagnostics is an important means to rationalise antibiotic therapy in patients. This review discusses the current diagnostic landscape and highlights promising novel diagnostic technologies in development that could aid in treatment and management of antibiotic-resistant UTIs.

Correlation of procalcitonin and c-reactive protein levels with pathogen distribution and infection localization in urinary tract infections

Aimed to explore the relationships between infection localization, bacterial species, and procalcitonin (PCT) and C-reactive protein (CRP) levels in urinary tract infections (UTIs). A retrospective study included 314 UTI hospitalized patients divided into two groups (268 with lower UTI, 46 with upper UTI) in a tertiary care hospital. PCT and CRP were performed. Bacterial isolates were identified using standard microbiological techniques, and statistical analyses were performed to assess associations between infection localization, bacterial species, PCT, and CRP levels. Age and gender showed no significant differences between the lower and upper UTIs. Escherichia coli dominated as the leading UTI pathogen. A positive correlation (r = 0.646, P < 0.001) between PCT and CRP levels was found. The subgroup with ureteritis in the upper UTI category exhibited the highest PCT and CRP levels. PCT and CRP exhibited favorable diagnostic potential in predicting upper UTIs, with AUCs of 0.644 and 0.629, respectively. The optimal cutoff values were 0.21 ng/mL for PCT and 60.77 mg/L for CRP. Sensitivities were 69.03% and 77.99%, while specificities were 56.52% and 47.83%, respectively. E. coli emerged as the predominant bacterium in UTIs. PCT and CRP demonstrated moderate diagnostic efficacy in distinguishing between upper and lower UTIs. Notably, PCT and CRP exhibited enhanced utility in identifying ureteritis.

Procalcitonin as a biomarker of nosocomial pneumonia in aneurysmal subarachnoid hemorrhage patients treated in neuro-ICU

BACKGROUND

Nosocomial pneumonia commonly develops in aneurysmal subarachnoid hemorrhage (aSAH) patients and is associated with poor prognosis of these patients. This study is designed to verify the predictive value of procalcitonin (PCT) on nosocomial pneumonia in aSAH patients.

METHODS

298 aSAH patients received treatments in the neuro-intensive care unit (NICU) of West China hospital were included. Logistic regression was conducted to verify the association between PCT level and nosocomial pneumonia and to construct a model for predicting pneumonia. Area under the receiver operating characteristic curve (AUC) were calculated to evaluate the accuracy of the single PCT and the constructed model.

RESULTS

90 (30.2%) patients developed pneumonia during hospitalizations among included aSAH patients. Pneumonia group had higher procalcitonin level (p < 0.001) than non-pneumonia group. The mortality (p < 0.001), mRS (p < 0.001), length of ICU stay (p < 0.001), length of hospital stay (p < 0.001) were both higher or longer in pneumonia group. Multivariate logistic regression indicated WFNS (p = 0.001), acute hydrocephalus (p = 0.007), WBC (p = 0.021), PCT (p = 0.046) and C-reactive protein (CRP) (p = 0.031) were independently associated with the development of pneumonia in included patients. The AUC value of procalcitonin for predicting nosocomial pneumonia was 0.764. Composed of WFNS, acute hydrocephalus, WBC, PCT and CRP, the predictive model for pneumonia has higher AUC of 0.811.

CONCLUSIONS

PCT is an available and effective predictive marker of nosocomial pneumonia in aSAH patients. Composed of WFNS, acute hydrocephalus, WBC, PCT and CRP, our constructed predictive model is helpful for clinicians to evaluate the risk of nosocomial pneumonia and guide therapeutics in aSAH patients.

Biomarkers for risk stratification and antibiotic stewardship in elderly patients

PURPOSE

Optimal treatment of infections in the elderly patients population is challenging because clinical symptoms and signs may be less specific potentially resulting in both, over- and undertreatment. Elderly patients also have a less pronounced immune response to infection, which may influence kinetics of biomarkers of infection.

METHODS

Within a group of experts, we critically reviewed the current literature regarding biomarkers for risk stratification and antibiotic stewardship in elderly patients with emphasis on procalcitonin (PCT).

RESULTS

The expert group agreed that there is strong evidence that the elderly patient population is particularly vulnerable for infections and due to ambiguity of clinical signs and parameters in the elderly, there is considerable risk for undertreatment. At the same time, however, this group of patients is particularly vulnerable for off-target effects from antibiotic treatment and limiting the use of antibiotics is therefore important. The use of infection markers including PCT to guide individual treatment decisions has thus particular appeal in geriatric patients. For the elderly, there is evidence that PCT is a valuable biomarker for assessing the risk of septic complications and adverse outcomes, and helpful for guiding individual decisions for or against antibiotic treatment. There is need for additional educational efforts regarding the concept of "biomarker-guided antibiotic stewardship" for health care providers caring for elderly patients.

CONCLUSION

Use of biomarkers, most notably PCT, has high potential to improve the antibiotic management of elderly patients with possible infection for improving both, undertreatment and overtreatment. Within this narrative review, we aim to provide evidence-based concepts for the safe and efficient use of PCT in elderly patients.

The Diagnostic Accuracy Of Procalcitonin for Urinary Tract Infection in Hospitalized Older Adults: a Prospective Study

BACKGROUND

The diagnosis of urinary tract infection (UTI) is challenging among hospitalized older adults, particularly among those with altered mental status.

OBJECTIVE

To determine the diagnostic accuracy of procalcitonin (PCT) for UTI in hospitalized older adults.

DESIGN

We performed a prospective cohort study of older adults (≥65 years old) admitted to a single hospital with evidence of pyuria on urinalysis. PCT was tested on initial blood samples. The reference standard was a clinical definition that included the presence of a positive urine culture and any symptom or sign of infection referable to the genitourinary tract. We also surveyed the treating physicians for their clinical judgment and performed expert adjudication of cases for the determination of UTI.

PARTICIPANTS

Two hundred twenty-nine study participants at a major academic medical center.

MAIN MEASURES

We calculated the area under the receiver operating characteristic curve (AUC) of PCT for the diagnosis of UTI.

KEY RESULTS

In this study cohort, 61 (27%) participants met clinical criteria for UTI. The median age of the overall cohort was 82.6 (IQR 74.9-89.7) years. The AUC of PCT for the diagnosis of UTI was 0.56 (95% CI, 0.46-0.65). A series of sensitivity analyses on UTI definition, which included using a decreased threshold for bacteriuria, the treating physicians' clinical judgment, and independent infectious disease specialist adjudication, confirmed the negative result.

CONCLUSIONS

Our findings demonstrate that PCT has limited value in the diagnosis of UTI among hospitalized older adults. Clinicians should be cautious using PCT for the diagnosis of UTI in hospitalized older adults.

Guidelines for the Use of Procalcitonin for Rational Use of Antibiotics

How to cite this article: Khilnani GC, Tiwari P, Zirpe KG, Chaudhary D, Govil D, Dixit S, et al. Guidelines for the Use of Procalcitonin for Rational Use of Antibiotics. Indian J Crit Care Med 2022;26(S2):S77-S94.

Risk factors for concomitant positive midstream urine culture in patients presenting with symptomatic ureterolithiasis

In patients with symptomatic ureterolithiasis, immediate treatment of concomitant urinary tract infection (UTI) may prevent sepsis. However, urine cultures require at least 24 h to confirm or exclude UTI, and therefore, clinical variables may help to identify patients who require immediate empirical broad-spectrum antibiotics and surgical intervention. Therefore, we divided a consecutive cohort of 705 patients diagnosed with symptomatic ureterolithiasis at a single institution between 2011 and 2017 into a training (80%) and a testing cohort (20%). A machine-learning-based variable selection approach was used for the fitting of a multivariable prognostic logistic regression model. The discriminatory ability of the model was quantified by the area under the curve (AUC) of receiver-operating curves (ROC). After validation and calibration of the model, a nomogram was created, and decision curve analysis (DCA) was used to evaluate the clinical net-benefit. UTI was observed in 40 patients (6%). LASSO regression selected the variables elevated serum CRP, positive nitrite, and positive leukocyte esterase for fitting of the model with the highest discriminatory ability. In the testing cohort, model performance evaluation for prediction of UTI showed an AUC of 82 (95% CI 71.5–95.7%). Model calibration plots showed excellent calibration. DCA showed a clinically meaningful net-benefit between a threshold probability of 0 and 80% for the novel model, which was superior to the net-benefit provided by either one of its singular components. In conclusion, we developed and internally validated a logistic regression model and a corresponding highly accurate nomogram for prediction of concomitant positive midstream urine culture in patients presenting with symptomatic ureterolithiasis.

Role of the urinary N-acetyl-beta-D-glucosaminidase/creatinine (NAG/Cr) ratio in discriminating between true and false pyuria in sterile urine bag specimens

INTRODUCTION

Urethral catheterization (CATH) and suprapubic aspiration (SA) are reliable methods of collecting urine for the diagnosis of urinary tract infections (UTIs), but both are invasive and difficult. Therefore, urine collection through a sterile urine bag (SUB) is commonly used for UTI screening. However, when pyuria is found in SUB specimens, it is difficult to interpret whether this result is true or false.

OBJECTIVE

We aimed to determine the diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria in SUB specimens for children with suspected UTIs.

STUDY DESIGN

This retrospective study included children 2-24 months of age presenting to the pediatric emergency department (PED) and in whom urinary NAG and creatinine levels were measured and a urine culture was performed between January 1, 2018, and December 31, 2019. Children with the presence of pyuria in SUB specimens were categorized into true or false pyuria groups depending on whether pyuria was present in CATH specimens. The diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria was identified using receiver operating characteristic (ROC) curve analysis. The optimal cutoff was calculated based on ROC curve analysis. Sensitivity, specificity, and positive and negative likelihood ratios were assessed for optimal cutoff values.

RESULTS

Among 606 children with measured urinary NAG levels, 144 children with pyuria in SUB specimens were included in the analyses. Pyuria was consistently present in the CATH specimens of 67 (46.5%) children and absent in those of 77 (44.5%) children. The urinary NAG/Cr ratio was significantly higher in the true pyuria group than in the false pyuria group (21.5 IU/g; 95% confidence interval [CI]: 12.3-35.6; vs 9.6 IU/g; 95% CI: 6.7-16.1, P < 0.001). The area under the ROC curve (AUC) for the urinary NAG/Cr ratio was 0.776 (95% CI: 0.700-0.851). The optimal cutoff of 18.85 IU/g corresponded to the best combination of sensitivity (58.2, 95% CI: 46.4-70.0) and specificity (83.3, 95% CI: 74.7-91.6), with positive and negative likelihood ratios of 3.49 (95% CI: 2.04-5.97) and 0.50 (95% CI: 0.37-0.68), respectively.

CONCLUSION

The urinary NAG/Cr ratio may be a potential indicator discriminating true pyuria from false pyuria in SUB specimens in the PED. However, large prospective studies are required to implement the NAG/Cr ratio in clinical practice.

The Effect of Pre-TURP Bladder Irrigation with 0.2% Chlorhexidine in Patients with Foley Catheter Regarding Postoperative Bacteremia Decrease

Background: Transurethral resection of the prostate (TURP) has been widely used for patients suffering from bladder colonization with bacteria, increasing the probability of bacteremia and sepsis despite consuming prophylaxis antibiotics. Objectives: The study aimed to evaluate the effect of pre- TURP bladder irrigation with 0.2% chlorhexidine in reducing postoperative bacteremia. Methods: This clinical trial study was conducted on 60 benign prostatic hyperplasia (BPH) patients who were candidates for TURP in the urology department of Al-Zahra Hospital. All patients suffered from urinary catheters, and they were allocated into two groups (n = 30). Antibiotic prophylaxis was prescribed for all the patients. In the case group, the bladder was rinsed by chlorhexidine 0.2% before TURP; however, and the bladder in the control group was rinsed by distilled water. Postoperative bacteremia were evaluated using procalcitonin (PCT) measurement and BACTEC automated blood culture six hours after surgery. Results: Positive BACTEC blood culture was observed in three (10%) and no (0%) patients in the control and case groups, respectively (P = 0.071). Moreover, 6.6 % and 46.6 % of the patients in the control group had low and high PCT levels, respectively. Furthermore, 40 % and 6.66 % of the patients in the case group had low and high PCT levels, respectively. There was a significant difference between the two groups in terms of the PCT level (P < 0.01). Conclusions: The frequency of patients with a high PCT level was higher in the control group than in the case group, suggesting that chlorhexidine in the catheterized patients undergoing TURP reduced the number of bacteria in the bladder.

Limited Utility of Procalcitonin in Identifying Community-Associated Bacterial Infections in Patients Presenting with Coronavirus Disease 2019

The role of procalcitonin in identifying community-associated bacterial infections among patients with coronavirus disease 2019 is not yet established. In 2,443 patients with 148 bacterial coinfections, mean procalcitonin levels were significantly higher with any bacterial infection (13.16 ± 51.19 ng/ml; P = 0.0091) and with bacteremia (34.25 ± 85.01 ng/ml; P = 0.0125) than without infection (2.00 ± 15.26 ng/ml).

The role of procalcitonin in identifying community-associated bacterial infections among patients with coronavirus disease 2019 is not yet established. In 2,443 patients of whom 148 had bacterial coinfections, mean procalcitonin levels were significantly higher with any bacterial infection (13.16 ± 51.19 ng/ml; P = 0.0091) and with bacteremia (34.25 ± 85.01 ng/ml; P = 0.0125) than without infection (2.00 ± 15.26 ng/ml). Procalcitonin (cutoff, 0.25 or 0.50 ng/ml) did not reliably identify bacterial coinfections but may be useful in excluding bacterial infection.

Clinical manifestations, laboratory markers, and renal ultrasonographic examinations in 1-month to 12-year-old Iranian children with pyelonephritis: a six-year cross-sectional retrospective study

BACKGROUND

Upper urinary tract infection (UTI) or pyelonephritis may increase the pathogenesis rate and risk of severe complications in children due to kidney atrophy.

OBJECTIVE

A set of clinical symptoms, laboratory markers, and ultrasound findings were assessed to achieve the early diagnosis and prognosis of pyelonephritis in hospitalized pediatrics.

METHODS

A cross-sectional study with 104 Iranian children (95 girls and 9 boys) aged 1 month to 12 years with acute pyelonephritis during 2012-2018 was conducted. The ultrasound examination of kidneys and urinary tract during hospitalization, the incidence of clinical symptoms, and laboratory markers in blood and urine were monitored to identify the best predictive factors of early diagnosis of this bacterial infection.

RESULTS

Three-fourth of the patients had one of the four clinical symptoms of abdominal pain, constipation, dysuria, and vomiting, while others were asymptomatic. A much frequency of pyuria (88.46%), Escherichia coli in urine (92.31%), leukocytosis (81.73%), and high ESR (> 10 mm/h, 92.30%) and CRP (> 10 mg/L, 82.82%) was observed. The kidney and urinary tract ultrasonography only in 32.7% of children revealed findings in favor of pyelonephritis (cystitis, ureteral stones, and hydronephrosis).

CONCLUSION

There was a high frequency of clinical signs and laboratory markers associated with pyelonephritis. Ultrasound alone was not an efficient tool to track febrile UTI as most patients presented normal sonography.

Procalcitonin as an early indicator of urosepsis following prostate biopsy

BACKGROUND

To investigate the usefulness of serum procalcitonin (PCT) in the early diagnosis of urinary tract infection (UTI) and urosepsis following transrectal prostate biopsy.

METHODS

In this prospective observational study, 227 patients who underwent transrectal ultrasound-guided prostate biopsy were evaluated. The relationship between urosepsis and age, serum PCT, C-reactive protein, prostate-specific antigen (PSA), prostate volume, PSA density and pathologic results following biopsy was assessed. Serum PCT level was measured in all patients immediately before the biopsy and at the post-biopsy day 2.

RESULTS

Of the 227 patients, 11 (4.8%) developed UTI with positive urine culture without urosepsis and 5 (2.2%) developed urosepsis within 30 days after biopsy. The concentration of PCT was within the normal range before the biopsy. Procalcitonin concentration at post-biopsy day 2 was significantly higher in patients who developed urosepsis (1.91 ± 2.99 ng/ml vs. 0.05 ± 0.08 ng/ml; p = .004) compared with non-UTI patients. Only elevated PCT level at post-biopsy day 2 was a statistically significant independent predictor of post-biopsy urosepsis. The area under the ROC curve for the prediction of urosepsis was 0.976 (95%CI: 0.941-1.000) and a cut-off 0.095 ng/ml in the level of PCT at post-biopsy day 2 yielded a sensitivity of 100% and specificity of 93.8% in detecting urosepsis following biopsy.

CONCLUSIONS

Procalcitonin appears to be a useful early biomarker to predict the urosepsis following prostate biopsy. Patients with elevated PCT value should be closely monitored after the biopsy.

Sensitivity of C-reactive protein and procalcitonin measured by Point-of-Care tests to diagnose urinary tract infections in nursing home residents: a cross-sectional study

Background

Diagnosing urinary tract infections (UTIs) in nursing home residents is complex, as specific urinary symptoms are often absent and asymptomatic bacteriuria (ASB) is prevalent. The aim of this study was to assess the sensitivity of blood C-reactive protein (CRP) and procalcitonin (PCT), measured by point-of-care tests (PoCTs), to diagnose UTIs in this setting.

Methods

Elderly residents (≥65 years old) with a suspected UTI were recruited from psychogeriatric, somatic, or rehabilitation wards across 13 participating nursing homes. CRP and PCT were tested simultaneously in the same study participants. To assess the tests’ sensitivities, a stringent definition of “true” UTI was used that included the presence of symptoms, urinary leucocytes, a positive urine culture, and symptom resolution during antibiotic treatment covering isolated uropathogen(s). The original sample size was 440 suspected UTI episodes, in order to detect a clinically relevant sensitivity of at least 65% when calculated using the matched analysis approach to compare both PoCTs.

Results

After enrollment of 302 episodes (68.6% of the planned sample size), an unplanned and funder-mandated interim analysis was done, resulting in premature discontinuation of the study for futility. For 247 of 266 eligible episodes, all mandatory items required for the true UTI definition (92.9%) were available. In total, 49 episodes fulfilled our stringent UTI definition (19.8%). The sensitivities of CRP (cut-off, 6.5 mg/L) and PCT (cut-off, 0.025 ng/mL) were 52.3% (95% confidence interval [CI], 36.7–67.5%) and 37.0% (95% CI, 23.2–52.5%), respectively.

Conclusions

Our results indicate that CRP and PCT are not suitable tests for distinguishing UTI and ASB in nursing home residents.

Clinical Trials Registration

Netherlands Trial Registry NL6293.

A diagnostic algorithm for detection of urinary tract infections in hospitalized patients with bacteriuria: The "Triple F" approach supported by Procalcitonin and paired blood and urine cultures

For acute medicine physicians, distinguishing between asymptomatic bacteriuria (ABU) and clinically relevant urinary tract infections (UTI) is challenging, resulting in overtreatment of ABU and under-recognition of urinary-source bacteraemia without genitourinary symptoms (USB). We conducted a retrospective analysis of ED encounters in a university hospital between October 2013 and September 2018 who met the following inclusion criteria: Suspected UTI with simultaneous collection of paired urinary cultures and blood cultures (PUB) and determination of Procalcitonin (PCT). We sought to develop a simple algorithm based on clinical signs and PCT for the management of suspected UTI. Individual patient presentations were retrospectively evaluated by a clinical "triple F" algorithm (F1 ="fever", F2 ="failure", F3 ="focus") supported by PCT and PUB. We identified 183 ED patients meeting the inclusion criteria. We introduced the term UTI with systemic involvement (SUTI) with three degrees of diagnostic certainty: bacteremic UTI (24.0%; 44/183), probable SUTI (14.2%; 26/183) and possible SUTI (27.9%; 51/183). In bacteremic UTI, half of patients (54.5%; 24/44) presented without genitourinary symptoms. Discordant bacteraemia was diagnosed in 16 patients (24.6% of all bacteremic patients). An alternative focus was identified in 67 patients, five patients presented with S. aureus bacteremia. 62 patients were diagnosed with possible UTI (n = 20) or ABU (n = 42). Using the proposed "triple F" algorithm, dichotomised PCT of < 0.25 pg/ml had a negative predictive value of 88.7% and 96.2% for bacteraemia und accordant bacteraemia respectively. The application of the algorithm to our cohort could have resulted in 33.3% reduction of BCs. Using the diagnostic categories "possible" or "probable" SUTI as a trigger for initiation of antimicrobial treatment would have reduced or streamlined antimicrobial use in 30.6% and 58.5% of cases, respectively. In conclusion, the "3F" algorithm supported by PCT and PUB is a promising diagnostic and antimicrobial stewardship tool.

Procalcitonin, C-reactive protein, and erythrocyte sedimentation rate for the diagnosis of acute pyelonephritis in children

BACKGROUND

In children with urinary tract infection (UTI), only those with pyelonephritis (and not cystitis) are at risk for developing long-term renal sequelae. If non-invasive biomarkers could accurately differentiate children with cystitis from children with pyelonephritis, treatment and follow-up could potentially be individualized. This is an update of a review first published in 2015.

OBJECTIVES

The objectives of this review were to 1) determine whether procalcitonin (PCT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) can replace the acute DMSA scan in the diagnostic evaluation of children with UTI; 2) assess the influence of patient and study characteristics on the diagnostic accuracy of these tests, and 3) compare the performance of the three tests to each other.

SEARCH METHODS

We searched MEDLINE, EMBASE, DARE, Web of Science, and BIOSIS Previews through to 17th December 2019 for this review. The reference lists of all included articles and relevant systematic reviews were searched to identify additional studies not found through the electronic search.

SELECTION CRITERIA

We only considered published studies that evaluated the results of an index test (PCT, CRP, ESR) against the results of an acute-phase ⁹⁹Tc-dimercaptosuccinic acid (DMSA) scan (conducted within 30 days of the UTI) in children aged 0 to 18 years with a culture-confirmed episode of UTI. The following cut-off values were used for the primary analysis: 0.5 ng/mL for procalcitonin, 20 mg/L for CRP and 30 mm/hour for ESR.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the selection criteria to all citations and independently abstracted data. We used the bivariate model to calculate pooled random-effects pooled sensitivity and specificity values.

MAIN RESULTS

A total of 36 studies met our inclusion criteria. Twenty-five studies provided data for the primary analysis: 12 studies (1000 children) included data on PCT, 16 studies (1895 children) included data on CRP, and eight studies (1910 children) included data on ESR (some studies had data on more than one test). The summary sensitivity estimates (95% CI) for the PCT, CRP, ESR tests at the aforementioned cut-offs were 0.81 (0.67 to 0.90), 0.93 (0.86 to 0.96), and 0.83 (0.71 to 0.91), respectively. The summary specificity values for PCT, CRP, and ESR tests at these cut-offs were 0.76 (0.66 to 0.84), 0.37 (0.24 to 0.53), and 0.57 (0.41 to 0.72), respectively.

AUTHORS' CONCLUSIONS

The ESR test does not appear to be sufficiently accurate to be helpful in differentiating children with cystitis from children with pyelonephritis. A low CRP value (< 20 mg/L) appears to be somewhat useful in ruling out pyelonephritis (decreasing the probability of pyelonephritis to < 20%), but unexplained heterogeneity in the data prevents us from making recommendations at this time. The procalcitonin test seems better suited for ruling in pyelonephritis, but the limited number of studies and the marked heterogeneity between studies prevents us from reaching definitive conclusions. Thus, at present, we do not find any compelling evidence to recommend the routine use of any of these tests in clinical practice.

Blood Neutrophil-to-Lymphocyte Ratio and Urine IL-8 Levels Predict the Type of Bacterial Urinary Tract Infection in Type 2 Diabetes Mellitus Patients

Background

Extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) are the most common uropathogens causing UTI (urinary tract infection) in type 2 diabetes mellitus (T2DM). Circulatory inflammatory markers such as C-reactive protein (CRP) and neutrophil-to-lymphocyte ratio (NLR) are usually dysregulated during UTI. However, the differential regulation of these inflammatory signatures during E. coli and K. pneumoniae UTI in T2DM has not been determined.

Methods

A case–control study on 466 patients was performed to investigate the inflammatory signatures indicative of ESBL-E. coli and K. pneumoniae UTIs in T2DM. Serum CRP levels and blood NLR for these patients were determined and associated with E. coli and K. pneumoniae ESBL uropathogen using multivariate logistic regression analysis. Urinary interleukin 8 (IL-8) levels were also assessed and associated with these two UTI uropathogens in T2DM. The association of the two ESBL-uropathogens with the survival outcomes of T2DM patients was also analyzed using Cox-proportional hazard model.

Results

T2DM patients with ESBL-E. coli UTI had lower serum CRP levels (median, CRP mg/dL 33.7 vs 39.8, respectively; P=0.023) and higher blood NLR (median, NLR 3.2 vs 2.6, respectively; P=0.010) compared to those with K. pneumoniae UTIs (P<0.001). Moreover, in T2DM, the urinary IL-8 levels was higher in ESBL-E. coli compared to those with K. pneumoniae UTIs (P<0.0001). After adjusting for confounders, including age, gender, serum albumin, hemoglobulin, leukocytes, and platelet counts, T2DM patients with blood NLR ≥ 3.5 were at higher risk for ESBL-E. coli UTIs than ESBL-K. pneumoniae UTIs (odds ratio [OR], 3.61, 95% confidence interval, Cl, 1.49–8.73; P=0.004). Moreover, T2DM patients with ESBL-E. coli UTIs had higher all-cause mortality (hazard ratio [HR], 4.09; 95%, 1.14–14.59) than those with K. pneumoniae UTIs.

Conclusion

Serum CRP levels, blood NLR, and IL-8 urinary levels differentiate ESBL-E. coli from K. pneumoniae UTIs in T2DM.

Fever of unknown origin, a rare presentation of metastatic prostate cancer: Case report

Metastatic prostate cancer can have an initial presentation with fever and systemic inflammatory response syndrome. Accurate diagnosis allows to differentiate this type of cancer from infectious conditions and to start early treatment. We report one case, in which the patient presented to the emergency department with lower urinary tract symptoms, fever and consumptive syndrome. Acute prostatitis was initially suspected, but subsequently prostate adenocarcinoma was diagnosed.

This case enables us to consider the possibility of prostate adenocarcinoma as the diagnose in patients with fever of unknown origin, and the role of procalcitonin to rule out the presence of infection.

The Role of Serum Procalcitonin in Predicting Bacterial Sepsis in Patients With Hypothyroidism

CONTEXT

Serum levels of procalcitonin (PCT), a protein produced by the thyroid C cells under physiologic conditions, are high during sepsis.

OBJECTIVE

To assess the test performance of serum PCT in predicting bacterial sepsis and septic shock in patients with hypothyroidism compared with those who have euthyroidism.

DESIGN AND METHODS

This retrospective study evaluated patients with no history of thyroid dysfunction (euthyroid), primary hypothyroidism [medical hypothyroidism (MH)], and postsurgical hypothyroidism from total thyroidectomy (TT) identified from a prospectively maintained database who had PCT testing from 2005 to 2018. Quick Sequential Organ Failure Assessment score ≥ 2 or positive bacterial cultures identified bacterial sepsis, and a mean arterial pressure less than 65 mm Hg or a vasopressor requirement defined septic shock. Sensitivity and specificity of PCT for evaluation of bacterial sepsis and septic shock were measured.

RESULTS

We identified 217 euthyroid patients, 197 patients with MH, and 84 patients with TT. Bacterial sepsis was found in 98 (45.2%), 92 (46.7%), and 36 (42.9%) of these patients, respectively (P > 0.05). Septic shock was identified in 13 (6.0%), 13 (6.6%), and 5 (6.0%) patients (P > 0.05), respectively. With use of a PCT cutoff of 0.5 µg/L for bacterial sepsis, the sensitivity was 59%, 61%, and 53% (P > 0.05) and specificity was 81%, 77%, and 81% (P > 0.05) for the diagnosis of bacterial sepsis in euthyroid, MH, and TT patients, respectively. With use of a PCT cutoff of 2.0 µg/L for septic shock, the sensitivity was 46%, 62%, and 63% (P > 0.05) and specificity was 86%, 82%, and 91% (P > 0.05) for the diagnosis of septic shock in these patients, respectively.

CONCLUSIONS

Despite the thyroidal origin of PCT, hypothyroidism did not affect the diagnostic performance of serum PCT levels in predicting bacterial sepsis or septic shock.

Sensitivity of point-of-care testing C reactive protein and procalcitonin to diagnose urinary tract infections in Dutch nursing homes: PROGRESS study protocol

INTRODUCTION

Suspected urinary tract infection (UTI) ranks among the most common reasons for antibiotic use in nursing homes. However, diagnosing UTI in this setting is challenging because UTI often presents with non-specific symptomatology. Moreover asymptomatic bacteriuria is common in elderly, which complicates attribution of causality to detection of bacteria in urine. These diagnostic challenges contribute to overuse of antibiotics and emergence of antimicrobial resistance in nursing homes. Given the diagnostic challenges, there is a need for point-of-care (POC) diagnostic tests to support clinical rules for diagnosing UTI. Procalcitonin (PCT) and C reactive protein (CRP) are inflammatory blood markers that have been proven useful to support diagnosis and monitoring of (bacterial) respiratory tract infections and sepsis. While limited studies suggest their usefulness in supporting UTI diagnosis, their utility has not been studied in elderly populations for this purpose.

METHODS AND ANALYSIS

In a 24-month matched prospective study, 'PROGRESS' will assess and compare the sensitivity of rapid POC measurements of blood CRP and PCT levels to support clinical rules for diagnosing UTI in nursing home residents. The primary outcome measure is sensitivity of the POC tests to identify patients with true UTI based on the predefined definition, as derived from receiver operating curves.

ETHICS AND DISSEMINATION

This study will be conducted in accordance with Good Clinical Practice guidelines and the principles of the Declaration of Helsinki. The study protocol is approved by the Medical Ethical Committee of Amsterdam UMC location VUmc with reference number 2017.350 and National Central Committee on Research involving Human Subjects with reference number NL62067.029.17.

TRIAL REGISTRATION NUMBER

NTR6467.

Evidence-Informed Practice: Diagnostic Questions in Urinary Tract Infections in the Elderly

Introduction

Routine interventions in the practice of medicine often lack definitive evidence or are based on evidence that is either not high quality or of only modest-to-marginal effect sizes. An abnormal urinalysis in an elderly patient presenting to the emergency department (ED) with non-specific symptoms represents one condition that requires an evidence-informed approach to diagnosis and management of either asymptomatic bacteriuria or urinary tract infection (UTI). The emergency provider often will not have access to urine cultures, and the risks associated with antibiotic use in the elderly are not without potentially significant side effects.

Methods

We performed a historical and clinical review of the growing body of literature suggesting measurable differences in the systemic immune response manifest among patients with asymptomatic pyuria and UTI, including increases in the pro-inflammatory cytokine interleukin-6 and the acute phase reactant procalcitonin.

Results

Serum procalcitonin, a peptide that undergoes proteolysis into calcitonin, has been demonstrated to quickly and reliably rise in patients with severe bacterial infections, and may serve as a potentially sensitive and specific marker for identification of bacterial illness.

Conclusion

In the absence of validated risk scores for diagnosing UTI in elderly patients presenting to the ED, there may be a role for the use of procalcitonin in this patient population.