STONE DISEASE

One Week of Ciprofloxacin Before Percutaneous Nephrolithotomy Significantly Reduces Upper Tract Infection and Urosepsis: A Prospective Controlled Study
Mariappan P, Smith G, Moussa SA, Tolley DA
Western General Hospital, Urology, Edinburgh, UK
BJU Int. 2006; 98: 1075-9

• Objective: To evaluate whether 1 week of ciprofloxacin before percutaneous nephrolithotomy (PCNL) in patients with stones of > or = 20 mm or pelvicalyceal dilatation, reduces urosepsis, as we previously reported that such patients have four times the risk of urosepsis after PCNL.
• Patients and Methods: Patients undergoing PCNL, and who fulfilled strict selection criteria, were recruited prospectively into a study which was conducted in two phases. The study methods were similar to those previously described; patients with dilated pelvicalyceal systems and/or stones of > or = 20 mm from phase 1 (previously published) acted as controls. In the subsequent phase, the same selection criteria applied and only those with stones of > or = 20 mm and/or dilated pelvicalyceal systems were given ciprofloxacin 250 mg twice daily for 1 week before PCNL and comprised the treatment arm. Midstream urine samples, renal pelvic urine and fragmented stones were collected to assess culture and sensitivity. Systemic inflammatory response syndrome (SIRS) was used to define urosepsis after PCNL. The urologists monitoring the patients after PCNL and conducting the analysis were all unaware of the characteristics of the stones or intravenous urography findings before PCNL. In all, 115 patients (54 in phase 1 and 61 in phase 2) were recruited, of whom 46 in phase 1 and 52 in phase 2 had stones of > or = 20 mm and/or a dilated pelvicalyceal system, and became the control and treatment arms, respectively.
• Results: The patient demographics were similar in both arms. There was three times less risk of upper tract infection (relative risk 3.4, 95% confidence interval 1.0-11.8, P = 0.04) and SIRS (2.9, 1.3-6.3, P = 0.004) in the patients receiving ciprofloxacin (treatment arm).
• Conclusions: The administration of oral ciprofloxacin for 1 week before PCNL in patients with stones of > or = 20 mm or dilated pelvicalyceal systems significantly reduced the risk of urosepsis.
  
  
• Editorial Comment
  The authors selected patients with significant hydronephrosis or stone burdens greater than 2 cm as candidates for this study, based on an initial study, which suggested that these patients were at greater risk for having an infected upper tract at the time of PCNL (1). However, this study also concluded that there was no correlation between SIRS and stone burden or degree of hydronephrosis.
  This is a non-blinded non-randomized study comparing results to a historical cohort. Accepting these limitations in study design, the results are still dramatic with regards to the 3-fold decrease in upper tract infection and SIRS. I am still not convinced regarding the clinical relevance of SIRS as defined by the criteria presented. For example, pain may increase the HR and RR, which would satisfy the criteria for SIRS. The stress of surgery can cause transient leukocytosis. Elevations in temperature and respiratory rates may be related to atelectasis. Preoperative antibiotics would not be anticipated to impact any of these events. The authors do not state what measures were taken to exclude other common causes of fever, tachycardia, and tachypnea during post-PCNL recuperation, such as atelectasis, hypovolemia, and pain. The Consensus panel that developed the definition of SIRS states that it is “overly sensitive and non-specific”, and caution that major surgical procedures as well as cardiogenic events may result in the clinical picture similar to SIRS(2). The consensus panel also cautions that sepsis should be defined as the presence of SIRS and infection.

References
1. Mariappan P, Smith G, Bariol SV, Moussa SA, Tolley DA: Stone and pelvic urine culture and sensitivity are better than bladder urine as predictors of urosepsis following percutaneous nephrolithotomy: a prospective clinical study. J Urol. 2005; 173: 1610-4.
2. Levy MM, Fink MP, Marshall JC, Abraham E, Angus D, Cook D, Cohen J, Opal SM, Vincent JL, Ramsay G; SCCM/ESICM/ACCP/ATS/SIS: 2001 SCCM/ESICM/ACCP/ATS/SIS International Sepsis Definitions Conference. Crit Care Med. 2003; 31: 1250-6.

Dr. Manoj Monga
Professor, Department of Urology
University of Minnesota
Edina, Minnesota, USA