[Validity and reliability of bladder ultrasound imaging for noninvasive estimation of urine volume in a major outpatient surgery department].
OBJECTIVE
To assess the validity and reliability of bladder ultrasound imaging for noninvasive estimation of urine volume, residual volume after voiding, volume before anesthetic induction and after surgery, and volume on sensing an urge to void.


METHODS
Study of a prospective series of 47 ASA 1-3 patients aged 18 to 79 years undergoing major outpatient surgical procedures under general anesthesia (n = 24) or regional anesthesia and sedation (n = 23). Urine volume was measured at baseline and on recovery (bladder volume by ultrasound and voided volume in a flask) and at the end of surgery (ultrasound only). The reliability and validity of the ultrasound estimation was calculated.


RESULTS
Agreement (intraclass correlation coefficient [ICC]) between 4 ultrasound-image estimations at baseline and the measured amount collected in a flask ranged from 0.70 to 0.86. The inter- and intra-measurement reliability was high, with ICC values greater than 0.80. The median error of estimation by ultrasound, with respect to measurement in the flask, was 23% at baseline and 29% after recovery. The amount in the flask was greater.


CONCLUSIONS
Ultrasound monitoring of urine in the bladder is reliable and valid, particularly for small volumes. The procedure is tolerated by patients.
Cabezón Gil
P
P
Unidad de Cirugía Mayor Ambulatoria, Hospital Clínico San Carlos, Madrid. pcabezon.hcsc@salud.madrid.org
López Yepes
L
L
Fernández Pérez
C
C
Barreales Tolosa
L
L
Montoya González
P
P
López Timoneda
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D013503:Surgery Department, Hospital; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging*; D016055:Urinary Retention / Q000000981:diagnostic imaging*; D014556:Urine; D055815:Young Adult