Pyelonephritis refers to inflammation of the kidney caused by a bacterial infection.
It is usually caused by a bacteria called Escherichia Coli, which is the most common organism causing lower UTIs.
E. Coli are gram-negative, anaerobic, rod-shaped bacteria that are commonly found in the intestine and faeces.
From here, E.coli can easily spread to the bladder, then up through the ureters and into the kidney, triggering an inflammatory response.
Other causes include Klebsiella pneumonia, enterococcus, pseudomonas, staphylococcus saprophyticus, Candida albicans (fungal)
Risk factors for pyelonephritis include:
- Females
- About 50-60% of women will have at least one UTI in their lifetime. This is because women have a shorter urethra, which means bacteria have a shorter distance to travel to reach the bladder.
- Anatomical abnormalities e.g. vesicoureteric reflux
- Pregnancy
- Diabetes mellitus
Symptoms:
Flank pain
- Nausea / vomiting
- Fever
- ± symptoms of acute cystitis (dysuria, frequency, urgency, haematuria)
Signs:
- Appear unwell
- Fever ≥ 38 C
- May have tachycardia or hypotension
- Costovertebral angle tenderness
- BEDSIDE
- Urine dipstick
- Leucocytes +ve
- Nitrites +ve
- May also be erythrocytes +ve
- Urine dipstick
- PATHOLOGY
- Urine Microscopy, Culture and Sensitivities (MCS)
- ↑ WCC
- ↑ CRP
- Blood cultures
- ↓ Decreased eGFR
- IMAGING
- USS or CT KUB to exclude other pathology such as abscess or kidney stones
If mild symptoms / hemodynamically stable:
- Disposition:
- Outpatient
- Management:
- Oral antibiotics e.g. amoxicillin + clavulanic acid, ciprofloxacin, cephalexin
- Analgesia
- Hydration
- Safety-netting
If moderate to severe symptoms / hemodynamically unstable:
- Disposition:
- Inpatient
- Management:
- Resuscitation
- IV antibiotics e.g. gentamicin, ceftriaxone, ampicillin or amoxicillin
- IV fluids
COMPLICATIONS
- Chronic Pyelonephritis caused by recurrent infections leading to scarring and damage to the kidneys. This can lead to chronic kidney disease.
