JU INSIGHT Practical Use of Self-Adjusted Nitrous Oxide During Transrectal Prostate Biopsy

By: Abigail J. Escobar, BS, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Suprita Krishna, MD, MHA, Beth Israel Deaconess Medical Center, Boston, Massachusetts; K. Mikayla Flowers, MA, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts; Alejandro Abello, MD, MPH, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Boris Gershman, MD, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Andrew A. Wagner, MD, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Peter Chang, MD, MPH, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Ruslan Korets, MD, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Christopher J. Mistretta, RN, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Kristen L. Schreiber, MD, PhD, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts; Aria F. Olumi, MD, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Heidi J. Rayala, MD, PhD, Beth Israel Deaconess Medical Center, Boston, Massachusetts | Posted on: 21 Feb 2024

Escobar AJ, Krishna S, Flowers KM, et al. Practical use of self-adjusted nitrous oxide during transrectal prostate biopsy: a double-blind randomized control trial. J Urol. 2024;211(2):214-222.

Study Need and Importance

There are many common ambulatory procedures performed by urologists that can be associated with significant physical and psychological distress for some patients. Low-dose nitrous oxide, commonly used in pediatrics and obstetrics, provides rapid-onset and -offset analgesia without necessitating the presence of anesthesia personnel, extended postprocedure monitoring, or escort home. Given the annual volume of over 1 million prostate biopsies in the United States, and the adoption of the longer transperineal and MRI fusion biopsies, we sought to determine the effectiveness of low-dose self-adjusted nitrous oxide (SANO) in improving a patient’s experience of care during transrectal prostate needle biopsy.

What We Found

In a prospective, double-blind, randomized, controlled trial of SANO vs oxygen, used in combination with routine periprostatic bupivacaine block, SANO was not associated with an improvement in primary end point of patient anxiety; however, SANO was associated with a reduction in patient-reported pain (Table). There were no differences in procedure time or 30-day complications. The operating urologists perceived biopsy was better tolerated in patients receiving SANO.

Table. Anxiety and Pain End Points

Postoperative outcomes	Oxygen, median (Q1, Q3)	SANO, median (Q1, Q3)	P value
State Trait Anxiety Index	12 (9, 14)	11 (7, 14)	.5
VAS-Anxiety	1 (0, 3)	0 (0, 3)	.1
VAS-Pain	1 (0, 2)	1 (0, 2)	.03
Abbreviations: Q, quartile; SANO, self-adjusted nitrous oxide; VAS, Visual Analog Scale.

Limitations

The study’s single-center design and predominantly White participant sample may limit generalizability of our findings. The operator survey has not been validated and may not accurately translate a urologist’s experience performing prostate biopsy with SANO. Further, the absence of an intention-to-treat analysis due to patient withdrawals as well as potential confounding by the study team’s presence should be considered when interpreting findings.

Interpretation for Patient Care

Nitrous oxide is known to be a rapid, safe, and cost-effective option to improve a patient’s experience of care during painful ambulatory procedures. This is the first study to evaluate the effectiveness of low-dose, patient-adjusted nitrous oxide during transrectal biopsy. Future studies may further elucidate specific patient populations that would most benefit from the incorporation of nitrous oxide in improving experience of care.