Clinical value of acute pyelonephritis grade based on computed tomography in predicting severity and course of acute pyelonephritis. J Comput Assist Tomogr. 2013;37:440-442. [PMID: 23674018 DOI: 10.1097/rct.0b013e318287365e]

Clinical and computed tomography factors associated with sepsis in women with clinically uncomplicated pyelonephritis

OBJECTIVE

Sepsis is major determinants of prognosis in acute pyelonephritis (APN). This study aimed to assess factors associated with the development of sepsis among patients with clinically uncomplicated APN.

SUBJECTS AND METHODS

We examined 463 patients presenting to our hospital without complications. We assessed clinical factors including demographic and laboratory features. Renal and extrarenal features on computed tomography (CT) were also analyzed. Risk factors of sepsis are assessed.

RESULTS

The study included 361 patients without (78.0%) and 102 patients with sepsis (22.0%). Crude and attributable mortality rates were 3.9% and 2.0% versus 1.4% and 0.6%, respectively, among patients with and without sepsis. Clinical risk factors for sepsis were age >65 years (odds ratio [OR] 1.79, P = 0.02), absence of flank pain (OR 1.59, P = 0.04), absence of costovertebral tenderness (OR 1.89, P = 0.03), diabetes mellitus (OR 2.25, P = 0.02), bacteremia (OR 2.8, P = 0.01), C-reactive protein level >100 mg/L (OR 1.42, P = 0.02), and lack of previous APN history (OR 1.76, P = 0.04). APN grade IV (OR 3.16, P = 0.01), high grade hydronephrosis (OR 1.50, P = 0.03), diffuse peritoneal thickening (OR 4.12, P = 0.01), and acute interstitial pulmonary edema (OR 3.73, P = 0.01) were the CT features predictive of septic shock.

CONCLUSIONS

Although uncomplicated APN was largely non-fatal, several clinical and CT features could lead to sepsis. Our findings may be useful for predicting sepsis risk and deciding whether intravenous antibiotic treatment and intensive management should be initiated for uncomplicated APN.

Clinical Usefulness of Contrast-Enhanced Computed Tomography in Patients with Non-Obstructive Acute Pyleonephritis

Objectives The aim of this study is to investigate the clinical utility of contrast-enhanced computed tomography (CE-CT) in patient with non-obstrcutive acute pyelonephritis (APN). Methods From 2007 to 2013, 537 APN patients who underwent a CE-CT scan within 24 hours after hospital admission were enrolled. We divided these patients into greater (50% or greater involvment, n = 143) and lesser (less than 50% involvement, n = 394) groups based on renal parenchymal involvement in CE-CT examination. We compared clinical characteristics between two groups and analyzed the clinical value of CE-CT scan as a reliable marker for predicting clinical severity and disease course in patient with non-obstructive APN. Results The mean estimated glomerular filtration rate was 70.6 ± 25.5 mL/min/1.73m2. Compared with patients in lesser group, the patients in greater group had lower serum albumin levels (3.5 ± 0.5 vs 3.8 ± 0.6, P < 0.01) and longer hosptal stay (10.1 ± 4.7 vs 8.8 ± 4.5, P < 0.05). In addition, acute kidney injury (AKI) (23.1% vs 11.4%, P < 0.005) and bacteremia (36.4% vs 26.8%, P = 0.02) were frequently developed in greater group, respectively. The overall incidence of AKI was 14.8% based on RIFLE criteria. In a multivariate logistic regression analysis for predciting AKI, age, presence of diabetes mellitus and the presence of renal parenchymal involvement of greater than 50% in CE-CT were significant predictors of AKI. Conclusions The CE-CT scan could be useful to predict the clinical severity and course in non-obstructive APN patients with preserved renal function.

Clinical Usefulness of Unenhanced Computed Tomography in Patients with Acute Pyelonephritis

BACKGROUND

Unenhanced computed tomography (UCT) may be useful for evaluating acute pyelonephritis; however, no study has compared UCT with enhanced computed tomography (ECT) as a diagnostic tool. We evaluated a clinical usefulness of UCT versus ECT in acute pyelonephritis (APN).

METHODS

We reviewed the clinical and radiological data from 183 APN-suspected patients who underwent UCT and ECT simultaneously at emergency room (ER) over a two-year period. Demographic, clinical parameters and computed tomography (CT) parameters of 149 patients were compared.

RESULTS

The average patient age was 61.2 (± 10) years: 31 patients were men. Ninety-nine (66.4%) patients showed stones (18.7%), perinephric infiltration (56%), swelling (21%), and hydronephrosis (6.7%) on UCT. Seventeen patients (11.4%) had an atypical clinical course, requiring additional tests for accurate diagnosis. In 7 patients UCT and ECT results did not differ; in 10 patients, the diagnosis changed on ECT. On ECT, 112/149 (75.2%) patients had stones (16.7%), perinephric infiltrations (57%), swelling (21%), and hydronephrosis (6.7%); 62.5% showed parenchymal involvement: 34 (22.8%) patients had no abnormal ECT findings. APN CT findings are similar on stone, perinephric infiltration, swelling and hydronephrosis on both CTs. Twelve patients (8.0%) had an abnormal ECT finding, i.e., low-grade (1 and 2) parenchymal involvement. Six (4%) patients developed contrast-induced acute kidney injury within 2 days after ECT.

CONCLUSION

We demonstrate that UCT is not inferior to ECT as an initial tool for evaluating APN for screening nephrolithiasis and hydronephrosis without the risk of contrast-induced acute kidney injury (CIAKI). However, patients with an atypical clinical course may still need ECT.

Are the unenhanced and excretory CT phases necessary for the evaluation of acute pyelonephritis?

Background The most widely accepted computed tomography (CT) protocol for diagnosis of acute pyelonephritis (APN) includes at least a pre- and post-contrast scan, which may expose patients to higher doses of ionizing radiation. Purpose To establish the accuracy, reproducibility, and degree of confidence in CT diagnosis of acute pyelonephritis (APN) and urolithiasis using only images obtained during the nephrographic phase. Material and Methods A retrospective study of 100 consecutive patients (88 women; age range, 19-70 years) with clinical and laboratory suspicion of APN and who underwent triphasic abdominal CT scans (non-contrast, nephrographic, and excretory phases) was performed. Two readers first evaluated independently only the nephrographic phase of scans, and, in a second session, the entire study. The diagnostic reference standard was settled by a third experienced radiologist who reviewed all triphasic scans and clinical data. Results The accuracy of only nephrographic phase for diagnosis of APN and urolithiasis was in the range of 90.3-91.78% and 96.27-99.25%, respectively. There was no significant difference in comparison with the triphasic reading (z: -0.4 - 0.2; P = 0.34-0.83). The average degree of confidence for APN also showed no significant variation for both readers ( P = 0.4 and 0.08). Almost perfect inter-observer agreements for the diagnosis of APN (k = 0.86, P < 0.001) and for urolithiasis (k = 0.84, P < 0.001) were observed when considering only the nephrographic phase. Conclusion CT assessment of APN and urolithiasis can be accurately performed using only the late nephrographic phase, with consequent dose reduction.

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.

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.