The effect of a 6 Fr catheter on flow rate in men

Abstract

Background:The pressure-flow study (PFS) is considered the gold standard for the detection of bladder outlet obstruction (BOO) in men. However, several studies have raised the possibility that transurethral catheterization might have an obstructive effect on PFS while others did not.Objectives:To evaluate the effect of a 6 Fr transurethral catheter on the pressure-flow study and to evaluate its clinical implication in men.Materials and Methods:A retrospective chart review study of 515 men referred for an evaluation of lower urinary tract symptoms and who underwent an urodynamic study (UDS). Of those, 133 met our inclusion/exclusion criteria. Non invasive free-flow studies (NIFFS) were performed before every UDS. Cystometrogram and PFS were performed through a 6 Fr transurethral catheter.Results:The maximal flow rate (Qmax) was significantly higher (P < 0.001) in the NIFFS (15.0 mL/s (range 9.0-23.0)) than in the PFS (11.0 mL/s (range 7.0-18.5)). This difference became greater (18.5 mL/s (range 10.0-30.3) vs. 13.0 mL/s (range 6.0-25.0), in favor of the NIFFS) when we analyzed only the patients (n = 34) who voided a similar volume. According to the International Continence Society (ICS) nomogram, the use of the PFS alone would have resulted in the upstaging of 14% of cases (10/71) in the overall population and 24% (4/17) in the sub-analyzed group.Conclusion:A 6 Fr transurethral catheter significantly lowers the maximal flow rate by 4 mL/s. Its presence resulted in an upstaging on the ICS nomogram. However, further studies will be necessary to confirm this upstaging.

Impact of urethral catheterization on uroflow during pressure-flow study

“…1 The aim of the present study was to investigate the effects of catheterization on uroflow via comparison of several urodynamic parameters during free uroflowmetry and pressure-flow study in three common aetiologies that frequently require urodynamic examination, namely benign prostatic hyperplasia, female stress incontinence, and lumbosacral spinal injury or spina bifida. [1][2][3]5 The present study showed that in patients with benign prostatic hyperplasia, Q max and Q ave were higher in free uroflowmetry than pressure-flow study, and T max had a shorter duration in free uroflowmetry versus pressure-flow study. Consistent with the present findings, a study into the effect of a 6 Fr catheter on flow rate in 133 male participants concluded that a 6 Fr transurethral catheter significantly lowered Q max by 4 ml/s.…”

“…Consistent with the present findings, a study into the effect of a 6 Fr catheter on flow rate in 133 male participants concluded that a 6 Fr transurethral catheter significantly lowered Q max by 4 ml/s. 5 According to another study however, 6 in the majority of male patients who presented with lower urinary tract symptoms secondary to benign prostatic hyperplasia, an 8 Ch (1 Ch ≈ 1 Fr) urethral catheter appeared to have no significant impact on uroflow rate. Regardless of the discrepancy in findings, the present authors believe that the effect of transurethral catheterization should be considered when analysing any results from pressure-flow study in patients with benign prostatic hyperplasia.…”

“… 1 The aim of the present study was to investigate the effects of catheterization on uroflow via comparison of several urodynamic parameters during free uroflowmetry and pressure-flow study in three common aetiologies that frequently require urodynamic examination, namely benign prostatic hyperplasia, female stress incontinence, and lumbosacral spinal injury or spina bifida. 1 – 3 , 5 …”

“…Uroflow in adult females is characterized by a shortened urethra and decreased resistance, 5 and normal female uroflow is influenced only by the voluntary part of the sphincter mechanism. 7 Due to adult female urinary physiology, uroflow may be expected to be less influenced by catheterization in female than in male patients.…”

Involvement of Chromosomally Encoded Homologs of the RRNPP Protein Family in Enterococcus faecalis Biofilm Formation and Urinary Tract Infection Pathogenesis

“…V583 Δebp (ebpA to -C deletion mutant) was used as a negative control, as this strain lacks a surface pilus previously shown to be involved with the initial attachment phase in biofilm development (9), and, as expected, showed a significant decrease in biofilm formation. Drip-flow conditions were chosen to closely mimic flow rates known to be present in catheterized patients (40). We directly enumerated the CFU to get a more quantitative measure of the differences exhibited by mutation of the RRNPP homologs (Fig.…”