In older patients, the diagnosis of acute pyelonephritis (APN) is challenging. The aim was to evaluate the added value of CT to history, physical examination and urinalysis for the diagnosis of APN in older patients with suspected infection with an unknown focus.

Retrospective diagnostic study.

Department of General Medicine in an acute care hospital in Japan.

Patients aged ≥65 years who underwent blood cultures, a urine culture, and chest and abdominal CT to detect the focus of infection were included.

Two radiologists independently reviewed four non-contrast CT signs: perirenal fat stranding, pelvicalyceal wall thickening, enlargement of the kidney and thickening of Gerota’s fascia. Findings on contrast-enhanced CT could not be evaluated due to an insufficient number of patients in whom contrast-enhanced CT was performed. An expert panel was used as the reference standard for APN. The added value of CT findings was quantified by comparing the diagnostic performance between a model based on 10 predictors available before CT and an extended model including the CT findings.

Of 473 patients, 61 (14.8%) were diagnosed with APN. When the laterality of the CT findings was taken into account, the model fit was not improved by adding them. In the laterality-insensitive analysis, the model performance was significantly improved by adding the CT signs (likelihood-ratio test p=0.03; c-index 0.89 vs 0.91, p=0.03). However, their clinical utility was only to improve the classification of 11.5% of patients with APN.

The added value of non-contrast CT findings to history, physical examination and urinalysis was limited for the diagnosis of APN in older patients with a suspected infection with an unknown focus.

Hyperkalaemia (HK) is a frequent complication in patients with chronic kidney disease (CKD) and/or chronic heart failure (CHF). HK must be managed, both to protect patients from its direct clinical adverse outcomes and to enable treatment with disease-modifying therapies including renin–angiotensin–aldosterone system inhibitors. However, the experiences of patients undergoing treatment of HK are not clearly understood. Optimising treatment decisions and improving long-term patient management requires a better understanding of patients’ quality of life (QOL). Thus, the aims of this research are: (1) to describe treatment patterns and the impact of treatment on a patient’s QOL, (2) to study the relationships between treatment patterns and the impact of treatment on a patient’s QOL and (3) to study the relationships between the control of serum potassium (S-K) and the impact of treatment on a patient’s QOL, in patients with HK.

This is a prospective cohort study with 6 months of follow-up in 30–40 outpatient nephrology and cardiology clinics in Japan. The participants will be 350 patients with CKD or CHF who received their first potassium binders (PB) prescription to treat HK within the previous 6 months. Medical records will be used to obtain information on S-K, on treatment of HK with PBs and with diet, and on the patients’ characteristics. To assess the impact of treatment on a patient’s QOL, questionnaires will be used to obtain generic health-related QOL, CKD-specific and CHF-specific QOL, and PB-specific QOL. Multivariable regression models will be used to quantify how treatment patterns and S-K control are related to the impact of treatment on a patient’s QOL.

Institutional review boards at all participating facilities review the study protocol. Patient consent will be obtained. The results will be published in international journals.

NCT05297409.