PURPOSE: We evaluated whether a 6Fr transurethral catheter affects urinary flow in women undergoing pressure-flow studies. MATERIALS AND METHODS: We retrospectively reviewed urodynamics database of 201 consecutive women referred for the evaluation of lower urinary tract symptoms from January 1997 to June 2000. Before the urodynamic study, all patients voided privately using a standard toilet and free uroflowmetry parameters were recorded. Then, a standard pressure-flow study was performed using 6Fr transurethral catheter. We excluded the patients with inadequate voided volume(<150ml) and volume difference more than 30% between two studies. Urinary flow parameters between the two studies were analysed by paired t-test according to voided volume, main urodynamic diagnosis and uroflowmetry pattern. RESULTS: Of 201 women, 144 were excluded and 57 were subjects of our analysis. According to voided volume, pressure-flow study parameters were significantly different from the equivalent free uroflowmetry parameters: the maximum flow rate and average flow rate were significantly lower and flow time was significantly longer in pressure-flow studies(p<0.01). According to main urodynamic diagnosis categories, the subgroups of patients with normal urodynamic study, bladder outlet obstruction, detrusor instability and others showed significantly lower maximum flow rate and average flow rate in pressure-flow studies(p<0.01). According to uroflowmetry pattern, obstructive patterns such as undulating and intermittent pattern were more common in pressure-flow studies. CONCLUSIONS: The 6Fr transurethral catheter used in pressure-flow studies significantly affects urinary flow parameters. In order to make a accurate diagnosis, we must not merely rely on the results of pressure-flow studies, but we must take into account patient's individual clinical situation and also, if available, the results of free uroflowmetry in addition to pressure flow study parameters.
Catheters* ; Diagnosis ; Female ; Humans ; Lower Urinary Tract Symptoms ; Retrospective Studies ; Urinary Bladder Neck Obstruction ; Urodynamics

Background: Over the last decade, extracorporeal membrane oxygenation (ECMO) use in critically ill children has increased and is associated with favorable outcomes. Our study aims to evaluate the current status of pediatric ECMO in Korea, with a specific focus on its volume and changes in survival rates based on diagnostic indications. Methods: This multicenter study retrospectively analyzed the indications and outcomes of pediatric ECMO over 10 years in patients at 14 hospitals in Korea from January 2012 to December 2021. Four diagnostic categories (neonatal respiratory, pediatric respiratory, postcardiotomy, and cardiac-medical) and trends were compared between periods 1 (2012–2016) and 2 (2017–2021). Results: Overall, 1065 ECMO runs were performed on 1032 patients, with the annual number of cases remaining unchanged over the 10 years. ECMO was most frequently used for post-cardiotomy (42.4%), cardiac-medical (31.8%), pediatric respiratory (17.5%), and neonatal respiratory (8.2%) cases. A 3.7% increase and 6.1% decrease in pediatric respiratory and post-cardiotomy cases, respectively, were noted between periods 1 and 2.Among the four groups, the cardiac-medical group had the highest survival rate (51.2%), followed by the pediatric respiratory (46.4%), post-cardiotomy (36.5%), and neonatal respiratory (29.4%) groups. A consistent improvement was noted in patient survival over the 10 years, with a significant increase between the two periods from 38.2% to 47.1% (P = 0.004). Improvement in survival was evident in post-cardiotomy cases (30–45%, P = 0.002).Significant associations with mortality were observed in neonates, patients requiring dialysis, and those treated with extracorporeal cardiopulmonary resuscitation (P < 0.001). In pediatric respiratory ECMO, immunocompromised patients also showed a significant correlation with mortality (P < 0.001). Conclusion Pediatric ECMO demonstrated a steady increase in overall survival in Korea;however, further efforts are needed since the outcomes remain suboptimal compared with global outcomes.