Transrectal prostate biopsy is a common ambulatory procedure that can result in pain and anxiety for some men. Low-dose, adjustable nitrous oxide is increasingly being used to improve experience of care for patients undergoing painful procedures. This study seeks to evaluate the efficacy and safety of low dose (<45%) nitrous oxide, which has not been previously established for transrectal prostate biopsies.
A single-institution, prospective, double-blind, randomized controlled trial was conducted on patients undergoing transrectal prostate biopsies. Patients were randomized to receive either self-adjusted nitrous oxide or oxygen, in addition to routine periprostatic bupivicaine block. Nitrous oxide at levels between 20-45% were adjusted to patients' desired effect. Patients completed a visual analog scale for anxiety (VAS-A), State Trait Anxiety Inventory (STAI), and a visual analog scale for pain (VAS-P) immediately before and after biopsy. The blinded operating urologist evaluated ease of procedure. Periprocedural vitals and complications were assessed. Patients were allowed to drive home independently.
A total of 133 patients received either nitrous oxide (66) or oxygen (67). There was no statistically significant difference in the primary anxiety endpoint of STAI or the VAS-A scores between the nitrous oxide and oxygen groups. However, patients in the nitrous oxide group reported significantly lower VAS-P scores compared to the oxygen group (P = .026). The operating urologists' rating of tolerance of the procedure was better in the nitrous oxide group (P = .03). There were no differences in biopsy performance time. Complications were similarly low between the 2 groups.
Patient-adjusted nitrous oxide at levels of 20-45% is a safe adjunct during transrectal prostate biopsy. Although there was not an observed difference in the primary endpoint of anxiety, nitrous oxide was associated with lower patient-reported pain scores.
The Journal of urology. 2023 Nov 20 [Epub ahead of print]
Abigail J Escobar, Suprita Krishna, K Mikayla Flowers, Alejandro Abello, Boris Gershman, Andrew A Wagner, Peter Chang, Ruslan Korets, Christopher J Mistretta, Kristen L Schreiber, Aria F Olumi, Heidi Rayala
Division of Urologic Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts., Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham & Women's Hospital, Harvard Medical School, Boston, Massachusetts.