COMBINED USE OF THE PASTERNATSKY SIGN AND URINALYSIS INDICATORS: SCREENING FOR PYELONEPHRITIS IN PRIMARY CARE

Abstract

 Acute pyelonephritis is an upper urinary tract infection that may rapidly progress to systemic illness if recognition and treatment are delayed. In first-contact clinical practice, decision-making often relies on physical examination and point-of-care urine testing, yet each component can be insufficient when applied in isolation. This pilot diagnostic accuracy study evaluated a pragmatic combined screening approach using costovertebral angle tenderness elicited by percussion (Pasternatsky sign) together with dipstick urinalysis indicators, specifically leukocyte esterase and nitrite, to support early identification of suspected acute pyelonephritis. Adults presenting with fever and or flank pain accompanied by urinary symptoms were assessed using bedside percussion tenderness and dipstick testing, and findings were compared with a final clinical diagnosis supported by urine culture and imaging when clinically indicated. In a cohort of 200 participants, 60 met the reference standard for acute pyelonephritis. The combined approach demonstrated higher overall screening performance than either physical examination or dipstick testing alone, with a high negative predictive value, suggesting utility for ruling out acute pyelonephritis in low-to-moderate risk presentations and guiding triage for confirmatory evaluation and timely management.