Review Question - QID 104932

This patient is presenting with signs and symptoms consistent with complicated acute pyelonephritis. The next best step in management, whether complicated or uncomplicated pyelonephritis, is to obtain a urine analysis and urine culture.

Acute pyelonephritis is a manifestation of a urinary tract infection (UTI), which affects the upper urinary tract (renal parenchyma and renal pelvis.) Pyelonephritis is considered uncomplicated when the patient is healthy, premenopausal, non-pregnant, and does not have any underlying abnormalities in their urinary tract. Pyelonephritis is considered complicated in patients who have some sort of underlying issue that would increase their risk of not responding to therapy. The most common causative organism in acute pyelonephritis is Escherichia coli (E. coli.) Bacteria can affect the kidney in two ways: 1) hematogenously (i.e., septicemia, or infective endocarditis); 2) from the lower urinary tract (most common). Before administering antibiotics, urine cultures must be collected first in order to accurately determine the causative organism and its antibiotic sensitivities.

Ramakrishnan and Scheid present the diagnosis and management of acute pyelonephritis in adults. Using both a leukocyte esterase test and nitrite test has a sensitivity of 75-84% and a specificity of 82-98% for a UTI. In patients with acute pyelonephritis, urine cultures are positive in 90% of patients. Before initiating antibiotic therapy, cultures should be obtained. In cases where the diagnosis is uncertain, in those who are immunocompromised, and in those that hematogenous infection is suspected, blood cultures should be obtained.

Shields and Maxwell discuss the complications associated with acute pyelonephritis. Acute pyelonephritis may not be complicated, and eventually lead to resolution without any serious sequelae. However, there are cases by which it may be complicated by acute kidney injury, emphysematous pyelonephritis, papillary necrosis, or abscess formation in the renal or perinephric region.

Incorrect Answers:
Answer 1: Abdominal CT is usually not necessary to diagnosis acute pyelonephritis, but can be considered if the patient does not improve with treatment, or if you suspect other complications (i.e., obstruction, abscess formation).
Answer 2: Given that this patient's clinical presentation is highly suspicious for pyelonephritis, blood cultures are not necessary, and a urine culture will be sufficient.
Answers 4: Hospitalized patients who have complicated acute pyelonephritis may be treated with intravenous antibiotics (i.e., fluoroquinolones, ampicillin-sulbactam, cephalosporins). However, before initiating therapy, a urine sample for cultures to identify the pathogen and determine its sensitivities.
Answer 5: Doing nothing in a patient with suspected pyelonephritis is dangerous. Missing the diagnosis can cause the patient to become septic, develop an abscess, etc.