Diagnosis of voiding dysfunction by pressure-flow study in women

Table 1 Voiding patterns of “healthy, continent or asymptomatic” women

	Rud et al[13]	Rud et al[14]	Karram et al[15]	Pauwels et al[16]
No. of patients	16	6	30	26
Patients condition	Healthy	Healthy	Asymptomatic, continent	Healthy, history free, continent
Age, yr (range)	33 (23-73)	42 (37–54)	34	26
Definitions
Detrusor contraction	Not defined	Not defined	Increase in detrusor pressure of 5 cm H2O above resting pressure	Increase in detrusor pressure of 15 cm H2O above resting pressure1
Strain to void	Not defined	Not defined	Increase in abdominal pressure of at least 10 cm H2O above baseline	Increase in abdominal pressure of at least 10 cm H2O above baseline during the entire voiding phase
Voiding pattern
Drop in urethral pressure	16/16 (100%)	6/6 (100%)	Not studied	Not studied
Detrusor contraction	16/16 (100%)	6/6 (100%)	30/30 (100%)	26/26 (100%)
Strain to void	0/16 (0%)	0/6 (0%)	22/30 (73%)	11/26 (42%)

¹There was no definition of detrusor contraction but increase in detrusor pressures of at least 15 cm H₂O developed in all women.

Table 2 Comparison of the reference isovolumetric pressure with estimates given by detrusor coefficient/bladder contractility index and projected isovolumetric pressure 1¹

	Reference isovolumetric pressure (cm H2O)	DECO/BCI (pdetQmax + 5 Qmax)	PIP1 (pdetQmax + Qmax)
Mean ± SD (mean)	50 ± 25 (45)	133 ± 45 (128)	49 ± 17 (48)
5 and 95 percentiles	20/112	60/215	29/78
Mean difference (cm H2O) from reference (95%CI: Wilcoxon signed ranks test)	-	86 (76-96; P < 0.05)	0.2 (-5 to 5; P = 0.98)
Spearman’s coefficient of correlation with reference	-	0.21 (P = 0.06)	0.52 (P < 0.01)

¹Modified from Tan et al[30]. DECO: Detrusor coefficient; BCI: Bladder contractility index; PIP₁: Projected isovolumetric pressure 1.

Table 3 Urodynamic criteria to define bladder outlet obstruction and detrusor underactivity in women

Bladder outlet obstruction
Cutoff criteria[21]	pdetQmax≥ 25 cm H2O + Qmax ≤ 12 mL/s
Video-urodynamic criteria[23]	Radiographic evidence of obstruction between the bladder neck and distal urethra in the presence of a sustained detrusor contraction of any magnitude, usually associated with reduced or delayed urinary flow rate
Nomogram[24]	See Figure 3
Detrusor underactivity
Projected isovolumetric pressure 1[30]	pdetQmax + Qmax < 30 cm H2O
Cutoff criteria[32]	pdetQmax < 10 cm H2O + Qmax < 12 mL/s “and significant rise in abdominal pressure”