From the Guidelines
Yes, a white cell count (WCC) can increase following a nephrostomy procedure even without infection. This elevation occurs as part of the body's normal inflammatory response to tissue trauma during the procedure. When a nephrostomy tube is inserted through the skin and into the kidney, it causes local tissue damage that triggers the release of inflammatory mediators. These mediators stimulate bone marrow to produce and release more white blood cells into circulation, resulting in a temporary elevation of WCC. This sterile inflammatory response typically resolves within a few days as healing progresses 1.
Key Points to Consider
- The procedure itself can cause mild hematuria in approximately 50% of patients 1, which may also contribute to a temporary increase in WCC.
- Clinically significant bleeding, either into the collecting system or into the retroperitoneum, is less common but can occur 1, and this could potentially lead to a more significant increase in WCC.
- Other signs that would suggest infection rather than normal inflammatory response include fever, increasing pain, purulent discharge from the nephrostomy site, cloudy or foul-smelling urine, or systemic symptoms like chills.
- Monitoring trends in WCC rather than isolated values, along with clinical assessment, helps differentiate between normal post-procedural inflammation and true infection requiring antibiotic treatment.
Clinical Implications
Given the potential for a rise in WCC following a nephrostomy procedure without infection, it's crucial to monitor patients closely for signs of infection and to interpret laboratory results in the context of the patient's overall clinical picture 1. The most recent and highest quality study 1 supports the notion that while infection is a risk, not all post-procedural elevations in WCC are due to infection, emphasizing the need for careful clinical judgment.
From the Research
Nephrostomy Procedure and WCC
- A nephrostomy procedure can cause a temporary increase in white blood cell count (WCC) due to the body's response to the procedure, even in the absence of infection 2.
- Studies have shown that postoperative leukocytosis is common after percutaneous nephrolithotomy (PCNL) and can be a normal physiologic response to surgery 2.
- The increase in WCC can be significant, with an average postoperative WBC count increase of 4.2 ± 2.99 × 10(6) cells/μL over the first 2 postoperative days 2.
Infection Risk and WCC
- While an increased WCC can be a sign of infection, it is not always the case, and other factors such as the patient's overall health and the presence of other symptoms should be considered 2.
- A study found that the thresholds for postoperative WBC count and absolute WBC count difference were 14.05 × 10(6) cells/μL and an increase greater than 5.25 × 10(6) cells/μL, respectively, which were significantly associated with post-PCNL sepsis development 2.
- However, it is essential to note that these values are not definitive indicators of infection, and further evaluation is necessary to determine the cause of the increased WCC 2.
Nephrostomy Procedure and Infection
- Nephrostomy procedures can lead to infection, including urosepsis, especially if the patient has a pre-existing urinary tract infection or if the procedure is not performed under sterile conditions 3, 4.
- Antibiotic prophylaxis is often used to prevent infection after nephrostomy procedures, but its effectiveness in preventing bacteremia is still a topic of debate 5, 3, 6.
- A systematic review found that nephrostomy urine cultures are useful in clinical practice, particularly in selecting appropriate antimicrobial treatment for urosepsis following upper urinary obstruction 4.