A 33-year-old woman comes to the emergency department complaining of 2 days of urinary frequency, fever, and nausea. She has no other medical problems and takes no medications. She is sexually active with her husband, has had 2 uncomplicated pregnancies, and uses condoms for contraception. The patient has regular menstrual periods. Her temperature is 39 C (102 F), blood pressure is 112/60 mm Hg, pulse is 110/min, and respirations are 16/min. Examination shows left costovertebral angle tenderness but is otherwise unremarkable. Laboratory testing shows a white blood cell count of 17,000/µL with 8% bands. Urinalysis shows positive nitrite, many white blood cells, and 100 bacteria/hpf. A pregnancy test is negative. Appropriate cultures are obtained and the patient is started on empiric intravenous antibiotics. Which of the following is the most appropriate indication for CT scan of the abdomen and pelvis in this patient?

Question

A 33-year-old woman comes to the emergency department complaining of 2 days of urinary frequency, fever, and nausea.  She has no other medical problems and takes no medications.  She is sexually active with her husband, has had 2 uncomplicated pregnancies, and uses condoms for contraception.  The patient has regular menstrual periods.  Her temperature is 39 C (102 F), blood pressure is 112/60 mm Hg, pulse is 110/min, and respirations are 16/min.  Examination shows left costovertebral angle tenderness but is otherwise unremarkable.  Laboratory testing shows a white blood cell count of 17,000/µL with 8% bands.  Urinalysis shows positive nitrite, many white blood cells, and >100 bacteria/hpf.  A pregnancy test is negative.  Appropriate cultures are obtained and the patient is started on empiric intravenous antibiotics.  Which of the following is the most appropriate indication for CT scan of the abdomen and pelvis in this patient?

Quizplus · Accepted Answer

This patient's presentation is consistent with uncomplicated pyelonephritis. Patients with uncomplicated pyelonephritis usually develop symptoms of cystitis (dysuria, frequency, urgency, suprapubic pain, and/or hematuria) along with flank pain, abdominal or pelvic pain, nausea, vomiting, fever (>38 C), or costovertebral angle tenderness. Bacteria typically ascend the bladder, invade the ureters, and can enter the bloodstream to cause Gram-negative sepsis. Patients should have urine culture and receive empiric oral antibiotics against Gram-negative organisms (eg, fluoroquinolone). Hypotensive patients require hospitalization and blood cultures to determine the causative organism, evaluate for bacteremia, and check for drug-resistant organisms. These patients also need aggressive resuscitation with intravenous fluids and empiric intravenous antibiotics. Uncomplicated pyelonephritis does not require routine urological imaging (eg, CT of abdomen/pelvis), especially if the patient is improving clinically (Choices B and C). Imaging is typically reserved for patients with persistent clinical symptoms despite 48-72 hours of therapy, history of nephrolithiasis, or unusual urinary findings (eg, gross hematuria, suspicion for urinary obstruction). Complicated pyelonephritis involves progression of the initial pyelonephritis to renal corticomedullary abscess, perinephric abscess, emphysematous pyelonephritis, or papillary necrosis. Patients can develop sepsis with multiorgan failure, shock, and renal failure. Complicated pyelonephritis occurs more commonly in patients with conditions such as diabetes, kidney stones, immunosuppression, or other anatomic abnormalities of the urinary tract. These patients usually require imaging to evaluate for these complications, urological evaluation, and prompt therapy (medical/surgical). (Choices D and E) Positive blood cultures are commonly seen in uncomplicated pyelonephritis. Urine cultures can also identify the offending bacteria and help change or narrow the antibiotic coverage. However, imaging is indicated only in patients who do not improve with empiric antibiotics. Educational objective: Acute pyelonephritis can result in Gram-negative sepsis. Urine (and blood) cultures should be obtained routinely before administration of empiric antibiotics. Urological imaging is typically reserved for patients with persistent clinical symptoms despite 48-72 hours of therapy, history of nephrolithiasis, complicated pyelonephritis, or unusual urinary findings (eg, gross hematuria, suspicion for urinary obstruction). References: Diagnosis and management of acute pyelonephritis in adults (http://www.ncbi.nlm.nih.gov/pubmed/15768623) Clinical practice. uncomplicated urinary tract infection. (http://www.ncbi.nlm.nih.gov/pubmed/22417256)

A 33-Year-Old Woman Comes to the Emergency Department Complaining of 2