Diagnostic usefulness of procalcitonin as a marker of bacteremia in patients with acute pyelonephritis

Urine neutrophil gelatinase-associated lipocalin as a biomarker of adult pyelonephritis

BACKGROUND

Pyelonephritis is a common infection at any age. Urine neutrophil gelatinase-associated lipocalin (NGAL), a novel biomarker of acute renal failure, is related to pyelonephritis in pediatric patients, although the significance of this urine biomarker in adult patients are not clear. We investigated the relationship between urine NGAL of pyelonephritis and non-pyelonephritis.

PATIENTS AND METHODS

We prospectively enrolled adult patients who were hospitalized due to pyelonephritis or non-pyelonephritis. Pyelonephritis was diagnosed in patients with fever and bacteriuria, with no any other infection focuses. Non-pyelonephritis was diagnosed in patients who had fever and another infection focus without bacteriuria. Urine samples were collected on days 0, 3 and 7. Urine NGAL levels were measured by ELISA.

RESULTS

There were 35 patients in the pyelonephritis group and 19 patients in the non-pyelonephritis group. Urine NGAL level were significantly higher in the pyelonephritis group than the non-pyelonephritis group on day 0 (median 302 ng/mL vs 25 ng/mL, p = 0.006). The area under the receiver operating characteristic curve of NGAL was 0.78 (p = 0.006). Urine NGAL level had a specificity of 66.7% and sensitivity of 87.0% at the cut-off level of 250 ng/mL for diagnosing pyelonephritis.

CONCLUSIONS

Urine NGAL level at the diagnosis of infection are elevated in adult patients with pyelonephritis, but not in those with non-pyelonephritis. Urine NGAL might be a supportive biomarker for the diagnosis of pyelonephritis.

Current Status of Antibiotic Stewardship and the Role of Biomarkers in Antibiotic Stewardship Programs

The importance of antibiotic stewardship is increasingly emphasized in accordance with the increasing incidences of multidrug-resistant organisms and accompanying increases in disease burden. This review describes the obstacles in operating an antibiotic stewardship program (ASP), and whether the use of biomarkers within currently available resources can help. Surveys conducted around the world have shown that major obstacles to ASPs are shortages of time and personnel, lack of appropriate compensation for ASP operation, and lack of guidelines or appropriate manuals. Sufficient investment, such as the provision of full-time equivalent ASP practitioners, and adoption of computerized clinical decision systems are useful measures to improve ASP within an institution. However, these methods are not easy in terms of both time commitments and cost. Some biomarkers, such as C-reactive protein, procalcitonin, and presepsin are promising tools in ASP due to their utility in diagnosis and forecasting the prognosis of sepsis. Recent studies have demonstrated the usefulness of algorithmic approaches based on procalcitonin level to determine the initiation or discontinuation of antibiotics, which would be helpful in decreasing antibiotics use, resulting in more appropriate antibiotics use.

Procalcitonin, mid-regional proadrenomedullin and C-reactive protein in predicting treatment outcome in community-acquired febrile urinary tract infection

Background

A reduction in duration of antibiotic therapy is crucial in minimizing the development of antimicrobial resistance, drug-related side effects and health care costs. The minimal effective duration of antimicrobial therapy for febrile urinary tract infections (fUTI) remains a topic of uncertainty, especially in male patients, those of older age or with comorbidities. Biomarkers have the potential to objectively identify the optimal moment for cessation of therapy.

Methods

A secondary analysis of a randomized placebo-controlled trial among 35 primary care centers and 7 emergency departments of regional hospitals in the Netherlands. Women and men aged ≥18 years with a diagnosis of fUTI were randomly assigned to receive antibiotic treatment for 7 or 14 days. Patients indicated to receive antimicrobial treatment for more than 14 days were excluded from randomization. The biomarkers procalcitonin (PCT), mid-regional proadrenomedullin (MR-proADM), and C-reactive protein (CRP) were compared in their ability to predict clinical cure or failure through the 10–18 day post-treatment visit.

Results

Biomarker concentrations were measured in 249 patients, with a clinical cure rate of 94% in the 165 randomized and 88% in the 84 non-randomized patients. PCT, MR-proADM and CRP concentrations did not differ between patients with clinical cure and treatment failure, and did not predict treatment outcome, irrespective of 7 or 14 day treatment duration (ROC_AUC 0.521; 0.515; 0.512, respectively). PCT concentrations at presentation were positively correlated with bacteraemia (τ = 0.33, p < 0.001) and presence of shaking chills (τ = 0.25, p < 0.001), and MR-proADM levels with length of hospital stay (τ = 0.40, p < 0.001), bacteraemia (τ = 0.33, p < 0.001), initial intravenous treatment (τ = 0.22, p < 0.001) and time to defervescence (τ = 0.21, p < 0.001). CRP did not display any correlation to relevant clinical parameters.

Conclusions

Although the biomarkers PCT and MR-proADM were correlated to clinical parameters indicating disease severity, they did not predict treatment outcome in patients with community acquired febrile urinary tract infection who were treated for either 7 or 14 days. CRP had no added value in the management of patients with fUTI.

Trial registration

The study was registered at ClinicalTrials.gov [NCT00809913; December 16, 2008] and trialregister.nl [NTR1583; December 19, 2008].

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.

Diagnostic performance of initial serum lactate for predicting bacteremia in female patients with acute pyelonephritis

OBJECTIVES

The purpose of the present study was to investigate the diagnostic value of lactate for predicting bacteremia in female patients with acute pyelonephritis (APN).

METHODS

We conducted a retrospective study of female patients with APN who visited the study hospital emergency department. The demographics, comorbidities, physiologies, and laboratory variables including white blood cell count and segmented neutrophil count, C-reactive protein, and initial serum lactate levels were collected and analyzed to identify associations with the presence of bacteremia.

RESULTS

During the study period, a total of 314 patients were enrolled. One hundred twenty-three patients (39.2%) had bacteremia. Escherichia coli was the most frequent pathogen. Logistic regression analysis demonstrated that the lactate level was independently associated with the presence of bacteremia (odds ratio, 1.39 [95% confidence interval, 1.08-1.78]). The C-statistic of the lactate level was 0.67 (95% CI, 0.60-0.73). At a cutoff value of 1.4mmol/L, the lactate level predicted bacteremia with a sensitivity (53.7%), specificity (72.3%), positive predictive value (55.5%), negative predictive value (70.8%), positive likelihood ratio (1.93), and negative likelihood ratio (0.64).

CONCLUSION

The initial serum lactate level showed poor discriminative performance for predicting bacteremia in female patients with APN.

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.

Perioperative advantages of modified laparoscopic vs open splenectomy and azygoportal disconnection

AIM: To investigate perioperative outcomes in patients undergoing modified laparoscopic splenectomy or open splenectomy and azygoportal disconnection for portal hypertension.

METHODS: This study included 44 patients who underwent modified laparoscopic splenectomy and azygoportal disconnection (MLSD) and 71 who underwent open procedures for portal hypertension. Blood samples were collected before surgery and on days 1, 3, and 7 after surgery. Markers of liver and renal function, C-reactive protein (CRP), interleukin-6 (IL-6), and procalcitonin (PCT) were measured, and perioperative variables were compared between the two groups.

RESULTS: The modified laparoscopic group showed significantly better and faster recovery, better liver and renal function, and fewer complications than the open group. CRP, IL-6, and PCT concentrations on postoperative days 1, 3, and 7 were significantly lower in the modified laparoscopic group than in the open group.

CONCLUSION: MLSD was associated with lower inflammatory immune responses, less impairment of liver and renal function, and faster and better recovery.

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.