This is a clinical diagnosis, made on the basis of fever, flank pain, and tenderness, often with an elevated white count. It may affect
3. NONTRAUMATIC RENAL EMERGENCIES 33
FIGURE 3.9. a: Right pelviureteric junction (PUJ) obstruction on ultrasound. b: PUJ obstruction on CT. Note the normal-calibre ureter with hydronephrosis above. c: MAG3 renogram of PUJ obstruction demonstrating obstruction to excretion of radioisotope by the kidney. (See this figure in full color in the insert.)
one or both kidneys. There are usually accompanying symptoms suggestive of a lower urinary tract infection (frequency, urgency, suprapubic pain, urethral burning or pain on voiding) that led to the ascending infection, which resulted in the subsequent acute pyelonephritis. The infecting organisms are commonly Escherichia coli, enterococci (Streptococcus faecalis), Klebsiella, Proteus, and Pseudomonas.
34 J. REYNARD
FIGURE 3.9. Continued
Urine culture is positive for bacterial growth, but the bacterial count may not always be above the 100,000 colony-forming units (cfu)/mL of urine, which is the strict definition for urinary infection. Thus, if you suspect a diagnosis of acute pyelonephritis from the symptoms of fever and flank pain, but there are only 1000 cfu/mL, manage the case as acute pyelonephritis.
Investigation and Treatment
For those patients who have a fever but are not systemically unwell, outpatient management is reasonable. Culture the urine and start oral antibiotics according to your local antibiotic policy (which will be based on the likely infecting organisms and their likely antibiotic sensitivity). We use oral ciprofloxacin, 500 mg b.i.d. for 10 days.
If the patient is systemically unwell, admit them to hospital culture urine and blood, and start intravenous fluids and intravenous antibiotics, again selecting the antibiotic according to your local antibiotic policy. We use i.v. ampicillin 1 g t.i.d. and gentamicin, 3 mg/kg as a once daily dose.