The accuracy of clinical assessment of bladder volume

Abstract

Objective: To determine the usefulness of physical examination in detecting elevated bladder volume.

Design: A blinded study of clinical examination by physicians to detect elevated bladder volumes compared with a criterion standard (ultrasonic bladder volume measurement).

Setting: Outpatient department of a general hospital in New Zealand.

Participants: Sixteen healthy adult volunteers (age range, 21-37 y; body mass index range, 22.9-37.2 kg/m(2)) and 8 qualified resident physicians with 2 to 6 years of clinical experience.

Intervention: Elevated bladder volumes were achieved by randomly allocating the volunteers to void or not to void before the clinical examination.

Main outcome measure: Clinical examination of the abdomen by abdominal palpation and suprapubic percussion, compared with portable ultrasound findings, to determine whether a healthy adult has a full bladder.

Results: For bladder volumes of 400 to 600 mL, physical examination to detect a full bladder was 81% sensitive (95% confidence interval [CI], 54-96), 50% specific (95% CI, 39-68), and 55% accurate (95% CI, 45-65). The likelihood ratio for a positive finding on physical examination was 1.62 (95% CI, 1.17-2.24).

Conclusion: Physical examination of the abdomen by relatively junior physicians is unreliable in detecting bladder volumes between 400 and 600 mL in healthy volunteers.