				Using the search form

CASE OF THE MONTH

Diagnostic challenges from your case files

Erich Fogg, PA-C, MMSc, department editor; 1LT William A. Zarychta, MPAS, PA-C

CASE

The patient is a 35-year-old white woman who presented to the emergency department with a complaint of upper lumbar back pain for 1 week that waxed and waned. It increased with palpation of the right paraspinus muscle and with active and passive range of motion, and it worsened somewhat with deep inspiration. When the symptoms started, the patient thought she had a urinary tract infection (UTI). The pain had improved minimally with ibuprofen, and she had occasionally vomited over the past week (but not recently). She denied heavy lifting or trauma.

History One month ago, the patient's primary care provider diagnosed a UTI and prescribed antibiotics, which the patient took as directed until completed. The symptoms resolved completely. She denied cough, fever, chills, nausea, recent vomiting, or diarrhea and had no hematuria, dysuria, frequency, or urgency. The last menstrual period was 3 weeks ago and normal. The last bowel movement was today and also normal.

The patient has had multiple orthopedic surgeries performed on her hip, knee, and back. She denied kidney stones, pyelonephritis, or diabetes. She did not use tobacco.

Physical exam The patient was afebrile with warm, dry, pink skin. Examination of the head, eyes, ears, nose, and throat was unremarkable. The heart rate was regular, and auscultation revealed normal rhythm with no murmurs, rubs, or gallops. Lungs were clear, and there was no chest wall tenderness. There was moderate tenderness on palpation of the right paraspinus muscle in the L2-3 area but no cervical tenderness. The abdomen was soft and nontender with good bowel sounds in all quadrants; no pulsatile masses, organomegaly, distention, rigidity, or guarding was noted. The extremities were normal.

WHAT IS YOUR DIAGNOSIS?

Lumbar strain
Uncomplicated UTI
Pyelonephritis
Nephrolithiasis

DISCUSSION

Based on the physical exam, this patient was thought to have a lumbar strain. When laboratory tests were ordered, however, results were as follows: serum chemistry, normal except for a plasma glucose level of 124 mg/dL; CBC, normal except for a WBC count of 13.2 x 10⁹/L with a mild left shift; pregnancy test, negative; urinalysis, RBCs too numerous to count, 6 to 10 WBCs/hpf, and trace bacteria. Kidney-ureter-bladder radiographs demonstrated an approximately 8-mm calculus in the right kidney (see Figure 1). Follow-up spiral CT also showed this stone with mild to moderate hydronephrosis (see Figure 2).

Click here to view full-size graphic

Treatment Given the size of the stone and the evidence of hydronephrosis, we felt that the patient was unlikely to pass the stone spontaneously, and urology was consulted. The patient was taken to the operating room, and, using a stone retrieval basket, the urologist removed the calculus without difficulty and placed a stent. The patient was discharged home with no complications and made a complete recovery.

Comment Imaging studies should be performed for a suspected first episode of renal colic/calculus or if the diagnosis is unclear. Nephrolithiasis is typically a self-limiting condition, with at least 75% of stones containing calcium. Patients can be discharged home, with close urology follow-up in 24 to 48 hours, as long as pain is well controlled and there is no emesis, pyelonephritis, renal dysfunction, or urinary obstruction.

Mr. Zarychta is an emergency medicine physician assistant in the US Army currently deployed in support of Operation Enduring Freedom. The author has indicated no relationships to disclose relating to the content of this article. Mr. Fogg is Assistant Professor in and Program Director of the Physician Assistant Program at the College of Health Professions, University of New England, Portland, Me.