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Average Flow Rate (average + flow_rate)
Selected AbstractsMeasurement of pressure and flow rates during irrigation of a root canal ex vivo with three endodontic needlesINTERNATIONAL ENDODONTIC JOURNAL, Issue 7 2007C. Boutsioukis Abstract Aim, To monitor ex vivo intra-canal irrigation with three endodontic needles (25, 27 and 30 gauge) and compare them in terms of irrigant flow rate, intra-barrel pressure, duration of irrigation and volume of irrigant delivered. Methodology, A testing system was constructed to allow measurement of selected variables with pressure and displacement transducers during ex vivo intra-canal irrigation with a syringe and three different needles (groups A, B, C) into a prepared root canal. Ten specialist endodontists performed the irrigation procedure. Each operator performed ten procedures with each needle. Data recorded by the transducers were analysed using Friedman's test, Wilcoxon Signed Rank test, Mann,Whitney U -test and Kendall's Tb test. The level of significance was set to 95%. Results, Significant differences were detected among the three needles for most variables. Duration of delivery and flow rates significantly decreased as the needle diameter increased, whilst pressure increased up to 400,550 kPa. Gender of the operator had a significant impact on the results. Experience of the operators (years) were negatively correlated to volume of irrigant (all groups), to the duration of delivery (groups A, B) and to the average flow rate (group A). Conclusions, Finer diameter needles require increased effort to deliver the irrigant and result in higher intra-barrel pressure. The syringe and needles used tolerated the pressure developed. Irrigant flow rate should be considered as a factor directly influencing flow beyond the needle. Wide variations of flow rate were observed among operators. Syringe irrigation appears difficult to standardize and control. [source] Extracorporeal photopheresis with permanent subcutaneous right atrial cathetersJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 12 2007Hartmut Ständer Summary Background: Adequate peripheral venous access is crucial for successful extracorporeal photopheresis (ECP). As this approach is not always feasible in older patients and patients with graft-versus-host disease, central venous catheters play an increasing role in providing long-term vascular access for ECP.However, not all catheters are able to deliver the minimum flow rate of 7 ml/min for ECP. Patients and Methods: Eight different permanent subcutaneous right atrial catheters were connected in vitro to the UVAR® -XTSÔ photopheresis system and median flow rates were determined. In addition, in vivo flow rates of patients who received ECP, using either peripheral or central venous access, were determined. Results: Hemodialysis catheters with an internal diameter of 2.0 or 1.5 × 3.5 mm and a length up to 48 cm provided in vitro flow rates of 27,28 ml/min, almost identical to a peripheral access needle. Central venous catheters with a length of over 90 cm reached flow rates below 7 ml/min and are impractical for ECP. The analysis of 308 ECP collection cycles with peripheral vascular access revealed an average flow rate of 31.5 ± 6.4 ml/min. Only permanent subcutaneous right atrial catheters made for hemodialysis provided similar flow rates (Quinton PermCath Dual Lumen) (33.7 ± 4.7 ml/min, n = 198). Conclusions: Permanent subcutaneous hemodialysis catheters with a length of maximally 48 cm achieve optimal flow rates for ECP. They represent therefore the central venous access of choice in patients with inadequate peripheral vascular access. [source] Voiding reflex in chronic spinal cord injured cats induced by stimulating and blocking pudendal nerves,,NEUROUROLOGY AND URODYNAMICS, Issue 6 2007Changfeng Tai Abstract Aims To induce efficient voiding in chronic spinal cord injured (SCI) cats. Methods Voiding reflexes induced by bladder distension or by electrical stimulation and block of pudendal nerves were investigated in chronic SCI cats under ,-chloralose anesthesia. Results The voiding efficiency in chronic SCI cats induced by bladder distension was very poor compared to that in spinal intact cats (7.3,±,0.9% vs. 93.6,±,2.0%, P,<,0.05). In chronic SCI cats continuous stimulation of the pudendal nerve on one side at 20 Hz induced large amplitude bladder contractions, but failed to induce voiding. However, continuous pudendal nerve stimulation (20 Hz) combined with high-frequency (10 kHz) distal blockade of the ipsilateral pudendal nerve elicited efficient (73.2,±,10.7%) voiding. Blocking the pudendal nerves bilaterally produced voiding efficiency (82.5,±,4.8%) comparable to the efficiency during voidings induced by bladder distension in spinal intact cats, indicating that the external urethral sphincter (EUS) contraction was caused not only by direct activation of the pudendal efferent fibers, but also by spinal reflex activation of the EUS through the contralateral pudendal nerve. The maximal bladder pressure and average flow rate induced by stimulation and bilateral pudendal nerve block in chronic SCI cats were also comparable to those in spinal intact cats. Conclusions This study shows that after the spinal cord is chronically isolated from the pontine micturition center, bladder distension evokes a transient, inefficient voiding reflex, whereas stimulation of somatic afferent fibers evokes a strong, long duration, spinal bladder reflex that elicits efficient voiding when combined with blockade of somatic efferent fibers in the pudendal nerves. Neurourol. Urodynam. 26:879,886, 2007. © 2007 Wiley-Liss, Inc. [source] The effect of psychological motivation on volumes voided during uroflowmetry in healthy aged male volunteersNEUROUROLOGY AND URODYNAMICS, Issue 1 2006Yat-Ching Tong Abstract Aims To study the effect of psychological motivation on the voided volume during uroflowmetry in aged-male volunteers. Methods An open contest of free-flow rate was held for the elderly community. People over 60 years old with no prior history of lower urinary tract symptoms were invited to compete. Participants were given the suggestion to void only when strong desire was experienced because greater the volume, faster the flow. One month later, 20 of the male participants were asked to come back for an office uroflowmetry, given the instruction to hold until strong desire was experienced. The results of the maximum flow rate, mean flow rate, and voided volume were compared between these two tests. Results In the first uroflowmetry, the average voided volume for the 20 participants was 532,±,109 ml; maximum flow rate and average flow rate were 27.1,±,9.4, and 17.2,±,6.4 ml/sec, respectively. The voided volume decreased significantly in the second uroflowmetry (338,±,82 ml, P,<,0.01); the maximum and average flow rates did not changed significantly (24.2,±,9.5 and 14.9,±,6.9 ml/sec, respectively). No participant had a shift of more than one standard deviation between the two tests on the Siroky's flow-rate nomogram. Conclusions With psychological motivation to win the contest, the participants showed greater tolerance to bladder filling. This suggests that the state of mind can affect the perception on bladder sensation. On the other, the performance on emptying function is not significantly improved by motivation. Neurourol. Urdynam. © 2005 Wiley-Liss, Inc. [source] Comparison of tamsulosin and naftopidil for efficacy and safety in the treatment of benign prostatic hyperplasia: a randomized controlled trialBJU INTERNATIONAL, Issue 4 2005Momokazu Gotoh OBJECTIVES To compare the efficacy and safety of two ,1a/,1d adrenoceptor (AR) antagonists with different affinity for the ,1AR subtypes, tamsulosin and naftopidil, in the treatment of benign prostatic hyperplasia (BPH). PATIENTS AND METHODS Patients with BPH were randomized to receive either tamsulosin or naftopidil. The primary efficacy variables were the changes in the total International Prostate Symptom Score (IPSS), maximum flow rate on free uroflowmetry, and residual urine volume. The secondary efficacy variables were average flow rate, changes in the IPSS storage score, IPSS voiding score, and quality-of-life (QoL) Index score, from baseline to endpoint (12 weeks). Data on all randomized patients were included in the safety analyses for adverse effects and changes in blood pressure. RESULTS Of the 185 patients enrolled data for 144 who were eligible for inclusion in the efficacy analysis were analysed (75 from the tamsulosin and 69 from the naftopidil group). There was no significant difference in any variable at baseline between the groups. There were satistically significant improvements for all primary and secondary variables in both groups, except for residual urine in the tamsulosin group. However, there was no significant intergroup difference in the improvement of any efficacy variable between the groups. The adverse effects were comparable, with no significant differences in systolic and diastolic blood pressure after treatment in both groups. CONCLUSIONS This study suggests that naftopidil is as effective and safe as tamsulosin. Both drugs were effective in improving storage and voiding symptoms. However, there was no difference in clinical efficacy or adverse effects between the ,1 AR antagonists with different affinity to ,1 subtypes, ,1a and ,1d. [source] The correlation of voiding variables between non-instrumented uroflowmetery and pressure-flow studies in women with pelvic organ prolapseNEUROUROLOGY AND URODYNAMICS, Issue 6 2008Elizabeth Mueller Abstract Aims To (1) correlate peak and maximum flow rates from non-instrumented flow (NIF) and pressure-flow studies (PFS) in women with pelvic organ prolapse (POP); (2) measure the impact of voided volume and degree of prolapse on correlations. Methods We compared four groups of women with stages II,IV POP. Groups 1 and 2 were symptomatically stress continent women participating in the colpopexy and urinary reduction efforts (CARE) trial; during prolapse reduction before sacrocolpopexy, Group 1 (n,=,67) did not have and Group 2 (n,=,84) had urodynamic stress incontinence (USI). Group 3 (n,=,74) and Group 4 participants (n,=,73), recruited specifically for this study, had stress urinary incontinence (SUI) symptoms. Group 3 planned sacrocolpopexy. Group 4 planned a different treatment option. Participants completed standardized uroflowmetry and pressure voiding studies. Results Subjects' median age was 61 years; median parity 3% and 80% had stage III or IV POP. Based on the Blaivas,Groutz nomogram, 49% of all women were obstructed. NIF and PFS peak and average flow rates had low correlations with one another (0.31, P,<,0.001 and 0.35, P,<,0.001, respectively). When NIF and PFS voided volumes were within 25% of each other, the peak and average flow rate correlations improved (0.52, P,<,0.001 and 0.57, P,<,0.001, respectively). As vaginal prolapse increased, correlations between NIF and PFS peak and average flow rates decreased. Conclusion Peak and average flow rates are highly dependent on voided volume in women with prolapse. As the prolapse stage increases, correlations between NIF and PFS variables decrease. Neurourol. Urodynam. 27:515,521, 2008. © 2008 Wiley-Liss, Inc. [source] The effect of psychological motivation on volumes voided during uroflowmetry in healthy aged male volunteersNEUROUROLOGY AND URODYNAMICS, Issue 1 2006Yat-Ching Tong Abstract Aims To study the effect of psychological motivation on the voided volume during uroflowmetry in aged-male volunteers. Methods An open contest of free-flow rate was held for the elderly community. People over 60 years old with no prior history of lower urinary tract symptoms were invited to compete. Participants were given the suggestion to void only when strong desire was experienced because greater the volume, faster the flow. One month later, 20 of the male participants were asked to come back for an office uroflowmetry, given the instruction to hold until strong desire was experienced. The results of the maximum flow rate, mean flow rate, and voided volume were compared between these two tests. Results In the first uroflowmetry, the average voided volume for the 20 participants was 532,±,109 ml; maximum flow rate and average flow rate were 27.1,±,9.4, and 17.2,±,6.4 ml/sec, respectively. The voided volume decreased significantly in the second uroflowmetry (338,±,82 ml, P,<,0.01); the maximum and average flow rates did not changed significantly (24.2,±,9.5 and 14.9,±,6.9 ml/sec, respectively). No participant had a shift of more than one standard deviation between the two tests on the Siroky's flow-rate nomogram. Conclusions With psychological motivation to win the contest, the participants showed greater tolerance to bladder filling. This suggests that the state of mind can affect the perception on bladder sensation. On the other, the performance on emptying function is not significantly improved by motivation. Neurourol. Urdynam. © 2005 Wiley-Liss, Inc. [source] | ||||||||||