WCE 2017: Ureteral Stent Placement in Clinic Using Nitrous Oxide Analgesia: One Institution’s Experience 

Vancouver, Canada (UroToday.com)  Dr. Lawrence Tsai, urology resident from the Texas A&M College of Medicine, presented data on his institution utilizing a nitrous oxide analgesia system with the belief the system would allow stent placements and exchanges to be safely conducted in the clinic instead of the operating room (OR). As an introduction to his talk, Dr. Tsai explained how with current technological advancements, there has been an increased interest in performing endourologic procedures in the clinic. 
A retrospective chart review was done to identify which patients had stent placements or exchanges; stent placements done in the OR were excluded from the study. For each stent placement or exchange, a 15.5 Fr flexible or 22 Fr rigid cystoscope was utilized. Standard fluoroscopy, 1 % lidocaine jelly, and a single dose of an oral antibiotic were also utilized for each stent procedure. For select cases, nitrous oxide analgesia was administered. 

Of the total 565 patients, 76% (n=429) underwent primary stent placement and 24% (n=136) underwent stent exchanges. For 61.4% (n=347) of the patients, the primary reason they were receiving a stent was because of an obstructing ureteral stone. Of the 565 patients, 77% (n= 435) underwent nitrous oxide analgesia for their stent procedure. 

For the total of 38 complications that occurred, 19 were urinary tract infections (UTI). Other complications included ER visits for pain. A total of 17 patients were admitted after their procedure, most commonly for pyuria. Only 6 stent placements failed, 1 aborted due to patient intolerance. Of the failed stent placements, 3 had stents placed in the OR and 3 required a nephrostomy tube placement following the procedure. 

During the discussion, he further discussed how the nitrous oxide was administered by a trained clinic nurse and monitored with pulse oximetry for 30 minutes to an hour after stent placement. In conclusion, Dr. Tsai and his team found that utilizing nitrous oxide for office stent placement and exchanges is a safe alternative to these procedures being done in the OR, as shown with a low failure rate (~1%) and lack of long term complications.

Presented by: Lawrence Tsai

Authors: Graham Luke Machen, Lawrence Tsai, Preston Milburn, Patrick Lowry, Marawan El Tayeb 
Affiliation: Texas A&M College of Medicine/Baylor Scott & White Health at Temple, Texas   

Written by: Cyrus Lin, Department of Urology, University of California-Irvine at 35th World Congress of Endourology – September 12-16, 2017, Vancouver, Canada