The Effect of a Urethral Catheter on the Uroflow and its Correction

Lee, Jeong Zoo; Yoon, Joung Byung

Abstract

The technique of synchronous pressure-flow studies requires the use of either a transurethral or a suprapubic catheter. Although the flow is impaired by the presence of catheter, the use of transurethral catheter can eliminate unnecessary cystostomy procedure. We evaluated the effect of urethral catheter on the roflow. The maximal and average urinary flow rates of healthy volunteer of 24 male and 7 female were measured in the presence and absence of a 5Fr. and 8Fr. urethral catheter. A comparison of these flow rates showed that those measured with the catheter in situ were lower than those in the absence of a catheter. There was an insignificant decrease in maximal flow rate(MFR) from 20.8+/-6.3(ml/sec) to 20.4+/-4.9 and 19.0+/-5.2 with 5Fr. and 8Fr. urethral catheter, respectively The average flow rate(AFR) was also decreased insignificantly from 10.7+/-3.8(ml/sec) to 9.5+/-2.3 and 8.8+/-2.3 with 5Fr. and 8Fr. urethral catheter, respectively. The followings are correlation formulae of AFR and MFR according to diameter of urethral catheter in situ. MFR=0.79xMFR(5Fr.) + 4.71 (R square=0.37), MFR=0.74xMFR (8Fr.) + 6.92 (R square=0.32), AFR=1.00xAFR(5Fr.) + 1.48 (R square=0.35), AFR=1.23xAFR(8Fr.) - 0.15 (R square=0.59) (MFR : maximal flow rate, AFR : average flow rate).