Synopsis
Recognise renal parenchymal infection and urinary sepsis, obtain cultures, select tissue-active treatment and secure urgent drainage when obstruction makes antibiotics insufficient.
- Pyelonephritis causes fever, flank or loin pain, systemic upset and urinary symptoms, although lower urinary symptoms may be absent.
- Send a midstream urine culture before antibiotics in every suspected acute pyelonephritis case when this does not delay treatment.
- Assess for sepsis and obstruction at presentation; an infected blocked system needs drainage as well as antimicrobial therapy.
Key red flags
Hypotension, tachypnoea, confusion, mottling, rising lactate or oliguria indicates urinary sepsis.
Fever, rigors, loin or flank pain, costovertebral-angle tenderness, nausea and vomiting support pyelonephritis, with or without dysuria and frequency.
Investigation priorities
Confirm the urinary organism and allow directed antimicrobial treatment.
Management branches
Pyelonephritis is accompanied by organ dysfunction, shock, severe vomiting or inability to take oral treatment.
- Use ABCDE, measure glucose and lactate, establish access, monitor urine output and give oxygen and intravenous crystalloid according to physiology.
- Obtain urine and blood cultures promptly and start a locally recommended intravenous regimen adjusted for allergy, renal function and previous resistant isolates.
A non-pregnant adult is stable, can take fluids and medicine and has no immediate complication concern.
Key medicines
Cefalexin oral regimenGive 500 mg orally twice or three times daily for seven to ten days, using higher severe-infection dosing only within current guidance.
Co-amoxiclav oral regimenGive 625 mg orally three times daily for seven to ten days only when urine culture confirms susceptibility.