An 82-year-old man is evaluated in the preadmission clinic prior to a scheduled elective r… — USMLE Step 2 CK

An $82$ -year-old man is evaluated in the preadmission clinic prior to a scheduled elective right total knee arthroplasty. His past medical history is significant for hypertension, type $2$ diabetes mellitus, and benign prostatic hyperplasia. He reports feeling well and specifically denies dysuria, urinary frequency, urgency, gross hematuria, or flank pain. Vital signs are temperature $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure $130/80\text{ mmHg}$ , pulse $72\text{/min}$ , and respirations $14\text{/min}$ . Physical examination is unremarkable, with no costovertebral angle tenderness or suprapubic pain. A routine preoperative urinalysis reveals trace leukocyte esterase, positive nitrites, and $15$ - $20$ white blood cells per high-power field. Which of the following is the most appropriate next step in management regarding this patient's urinary findings?

Proceed with the scheduled surgery without targeted antimicrobial therapy for the urinary findingsAnswer
B
Prescribe a preoperative course of oral ciprofloxacin
C
Postpone the arthroplasty until a urine culture is finalized
D
Administer intravenous ceftriaxone specifically to sterilize the urinary tract
E
Prescribe oral nitrofurantoin to be taken for five days postoperatively

Answer

Proceed with the scheduled surgery without targeted antimicrobial therapy for the urinary findings

The correct action is to proceed with the surgery without targeted therapy. This patient has asymptomatic bacteriuria (ASB), which is common in older men with benign prostatic hyperplasia and patients with diabetes mellitus. By definition, ASB is the presence of bacteria in the urine without accompanying signs or symptoms of a urinary tract infection (e.g., dysuria, frequency, urgency, fever, suprapubic pain). According to current infectious disease guidelines and antimicrobial stewardship principles, screening and treatment for ASB are strongly discouraged for the vast majority of patients. The only well-established indications for screening and treating ASB are in pregnant women, patients undergoing endoscopic urologic procedures associated with mucosal trauma (e.g., transurethral resection of the prostate), and in patients who have recently received a renal transplant. An elective orthopedic procedure, such as a total knee arthroplasty, is not an indication to treat ASB. Studies have consistently shown that treating ASB prior to joint arthroplasty does not reduce the risk of surgical site infections and only serves to promote antibiotic resistance and potential adverse drug effects.

Step-by-Step Solution

Identify the patient's clinical state based on symptoms and labs.

The patient is an elderly diabetic man with pyuria and positive nitrites on urinalysis, but he entirely lacks systemic or local genitourinary symptoms.

Differentiating between a symptomatic urinary tract infection (UTI) and asymptomatic bacteriuria (ASB) relies primarily on the presence or absence of clinical symptoms.

Diagnose the urinary condition.

The clinical picture is diagnostic of asymptomatic bacteriuria (ASB).

ASB is defined as the isolation of a specified quantitative count of bacteria in an appropriately collected urine specimen from an individual without signs or symptoms of a UTI.

Recall the indications for treating asymptomatic bacteriuria.

Treatment is only indicated for pregnant women, patients undergoing invasive endoscopic urologic procedures associated with mucosal trauma, and recent renal transplant recipients.

Routine treatment in other populations does not improve outcomes and increases the risk of resistance.

Determine the appropriate management for this specific preoperative patient.

A total knee arthroplasty is a non-urologic orthopedic procedure, meaning the ASB does not require treatment or a delay of the surgery.

Treating ASB prior to joint replacement surgery does not reduce the incidence of prosthetic joint infections.

Key Concept

Management of asymptomatic bacteriuria in the preoperative setting

Question

Answer

Step-by-Step Solution

Key Concept

Common Mistakes

Topics

More questions from this topic