title: Pain after percutaneous nephrolithotomy: impact of nephrostomy tube size.
abstract: OBJECTIVE
  Percutaneous nephrolithotomy (PCNL) is the procedure of choice for managing large renal calculi. Investigations have recently focused on reducing the morbidity of the procedure and improving postoperative patient comfort by using smaller endoscopic instruments. We sought to evaluate the effect of a smaller percutaneous drainage catheter on postoperative pain.
  
  
  METHODS
  Thirty consecutive patients were randomized to receive either a 10F pigtail catheter or a 22F Councill-tip catheter for their percutaneous drainage after PCNL. The demographics were similar in the two groups, as was the rate of supracostal access (47% v 43%, respectively). Self-assessed analog pain scores were collected at 6 hours postoperatively as well as on the morning of the first and second postoperative days (POD). Total narcotic usage was tabulated using morphine equivalents. Complications, including the change from baseline hematocrit, were reviewed.
  
  
  RESULTS
  There was no significant difference in the change in hematocrit (6.8 v 6.2 percentage points, respectively). Those patients with the smaller nephrostomy tube noted significantly lower pain scores at 6 hours (3.75 v 5.3; P=0.03). Although the pain scores were lower on POD 1 and 2 for the 10F catheter group, the difference was not statistically different (1.9 v 2.9 and 1.25 v 1.9, respectively; both P>0.05). The patients having the 10F catheter required fewer narcotics: 78 mg v 91 mg, although the difference was not statistically significant.
  
  
  CONCLUSIONS
  The use of a small drainage catheter after PCNL is associated with lower pain scores in the immediate postoperative period, yet no statistically significant benefit to the patient with regard to comfort is demonstrated beyond 6 hours. In addition, there is a trend toward reduced narcotic requirements. Finally, there is no apparent increase in patient morbidity from the use of the smaller nephrostomy tubes.
authors.affiliation: Comprehensive Kidney Stone Center, Division of Urology, Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA. pktrow@aol.com
authors.forename: Paul K
authors.initials: PK
authors.lastname: Pietrow
authors.forename: Brian K
authors.initials: BK
authors.lastname: Auge
authors.forename: Costas D
authors.initials: CD
authors.lastname: Lallas
authors.forename: Robert W
authors.initials: RW
authors.lastname: Santa-Cruz
authors.forename: Glenn E
authors.initials: GE
authors.lastname: Newman
authors.forename: David M
authors.initials: DM
authors.lastname: Albala
authors.forename: Glenn M
authors.initials: GM
authors.lastname: Preminger
mesh_terms: D002404:Catheterization / Q000295:instrumentation*; D005260:Female; D006400:Hematocrit; D006801:Humans; D008297:Male; D008875:Middle Aged; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects* / Q000295:instrumentation*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000209:etiology*; D016896:Treatment Outcome