Urinary continence

In genitourinary organs, the bladder base, urethral sphincter, and prostate contain a receptors that mediate contraction and therefore promote urinary continence. The specific subtype of 04 receptor involved in mediating constriction of the bladder base and prostate is uncertain, but cxia receptors probably play an important role. This effect explains why urinary retention is a potential adverse effect of administration of the 04 agonist midodrine. 

The human uterus contains and B2 receptors. The fact that the Breceptors mediate relaxation may be clinically useful in pregnancy (see Clinical Pharmacology). The bladder base, urethral sphincter, and prostate contain receptors that mediate contraction and therefore promote urinary continence. The specific subtype of ai receptor involved in mediating constriction of the bladder base and prostate is uncertain, but uia receptors probably play an important role. The B2 receptors of the bladder wall mediate relaxation. Ejaculation depends upon normal a-receptor (and possibly purinergic receptor) activation in the ductus deferens, seminal vesicles, and prostate. The detumescence of erectile tissue that normally follows ejaculation is also brought about by norepinephrine (and possibly neuropeptide Y) released from sympathetic nerves. Alpha activation appears to have a similar detumescent effect on erectile tissue in female animals. 

PPA has been used in veterinary practice as an agent to help with urinary continence, primarily in dogs. Dogs commonly develop signs and symptoms of CNS stimulation. 

Ephedrine is also an a agonist and, as such, is capable of stimulating bladder smooth muscle. At one time, it was used to promote urinary continence (65,66). In animal models, when compared to norepinephrine, ephedrine is a relatively weak a-adrenergic agonist, possessing less than one-third the activity of norepinephrine (67). Ephedrine s usefulness as a bronchodila-tor is limited by the number of 3-receptors on the bronchi. The number of p-... 

The essential feature of enuresis is repeated involuntary or intentional voiding of urine by day or night that is not caused by a general medical condition (Table 61-7). Medical causes of inappropriate voiding (e.g., diabetes mellitus, diabetes insipidus, seizure disorders, or urinary tract infections) should be ruled out. Enuresis may be primary or secondary. Primary enuresis, the most common type, is diagnosed if the child has never established urinary continence. Secondary enuresis follows an established period (3 to 6 months) of urinary continence. 

Controlled studies demonstrated that tolterodine was significantly more effective than placebo and as effective as oxybutynin IR in decreasing the mean daily number of micturitions and increasing the mean volume voided per micturition (see Table 83-5). However, while three controlled trials showed significant decreases in the mean number of incontinence episodes per 24 hours as compared to placebo, most studies have not and the manufacturer s package insert does not claim a significant improvement in this parameter (see Table 83-5). The only controlled study of the ability of tolterodine to restore urinary continence reported an insignificant effect rate of 9% over placebo. ... 

In the past, ephedrine was used to treat Stokes-Adams attacks with complete heart block and as a CNS stimulant in narcolepsy and depressive states. It has been replaced by alternate treatments in each of these disorders. In addition, its use as a bronchodilator in patients with asthma has become much less extensive with the development of p2-selective agonists. Ephedrine has been used to promote urinary continence, although its efficacy is not clear. Indeed, the drug may cause urinary retention, particularly in men with benign prostatic hyperplasia. Ephedrine also has been used to treat the hypotension that may occur with spinal anesthesia. 

Long-acting sympathomimetics such as ephedrine are sometimes used to improve urinary continence in children with enuresis and in the elderly. This action is mediated by alpha receptors in the trigone of the bladder and, in men, the smooth muscle of the prostate. 

Inducing tissue generation at the base of the bladder can restore urinary continence from a state that constrains activity and limits quality of life. 

Urinary continence is more difficult to establish in the ventilator patient because of the variety of medications and fluid requirements. Many patients have comorbid coronary artery disease for which they require diuretics. Maintaining a good fluid balance is a challenge for the patient with a weak bladder, due to disuse or a long-term indwelling catheter. 

Weijerman PC, Schurmans JR, Hop WC. Morbidity and quality of life in patients with orthotopic and heterotopic continent urinary diversion. Urology 1996 51 51-56. 

There is widespread use of Crinum species throughout the African Continent for the treatment of a variety of ailments. In southern Africa, Crinum bulbispermum is used by the Zulu and Tswana for the treatment of aching joints, rheumatism, varicose veins, backache, septic sores and abscesses. Tswana also use the bulb to treat kidney or bladder infections while in Sotho cultures the bulb is used for stimulation of milk production (44, 43). Bulb decoctions of Crinum maco-wanii are taken for the treatment of swelling of the body and treatment of urinary tract problems by the Zulu and for itchy rashes by the Xhosa (43, 44,... 

Duloxetine (when approved for treatment of urinary in- continence), a-adrenergic receptor agonists, and topical (vaginal) estrogens (alone or together) are the therapies of choice in urethral underactivity (stress incontinence). 

This type of UI is known as stress urinary incontinence (SUI). Although the exact etiology of urethral underactivity and SUI in the woman is incompletely understood, clearly identifiable risk factors include pregnancy, childbirth, menopause, cognitive impairment, obesity, and age. The prevalence of SUI in women appears to peak during or after the onset of menopause. This implies that hormonal factors are important in maintaining continence. 

Abrams P, Cardozo L, Fall M, et al. The standardization of terminology of lower urinary tract function Report from the standardization subcommittee of the International Continence Society. Neurourol Urodyn 2002 21 167-178. 

Schmidt RA, The Oxybutynin XL Study Group. Efficacy of controlled-release, once-a-day oxybutynin chloride for urge urinary incontinence. Jerusalem, International Continence Society, Sept. 14—17, 1998 188. 

Takeda, M., Komeyama, T., Tsutsui, T., Hatano, A., Obara, K., Mizu-sawa, T., Koizumi, T., 1996. Molecular expression and pharmacological functions of beta-3 adrenoceptor in human urinary bladder detrusor. In Barbalias, G.A. (Ed.), International Continence Society 26th Annual Meeting. Monduzzi Editore, Bologna, pp. 153-156. 

Hampel R, Goedalia A and Zollnee H et al. (2000) Continous rise of urinary iodine excretion and drop in thyroid gland size among adolescents in Mecklenburg-Westpommemfrom 1993 to 1997. Exp Clin Endocrinol Diabetes 108 197-201. 

Parker, D., Callan, L., Harwood, J., Thompson, D.L., WUde, M., Gray, M., 2009. Nursing interventions to reduce the risk of catheter-associated urinary tract infection. Part 1 catheter selection. Journal of Wound Ostomy Continence Nursing 36, 23-34. 

Patients with urinary frequency and urinary retention do benefit from urodynamical evaluation to determine the voiding pressures, the volume that triggers the void, the effect of abdominal pressure, and the volume of void. A urology nurse or a physician can prescribe appropriate medications to address the above issues. Urodynamics may be performed at the bedside by a trained nurse and can provide prompt information to assist with a plan to address incontinence. This examination will prevent unnecessary wetness and improve the continence outcomes. 

The classification of the International Children s Continence Society should be used to eliminate confusion, to facilitate and enable comparative research and metaanalyses. This classification recognizes two main dysfunctions overactive bladder or unstable bladder (urge syndrome) and dysfunctional voiding. The common denominator of lower urinary tract dysfunction is bladder sphincter discoordination leading to chronic high intravesical pressure with resulting negative consequences for the urinary tract. 

The child, attempting to maintain continence during such contractions, must voluntarily and tightly constrict the external urethral sphincter to stay dry. This results in simultaneous and unphysi-ological contraction of both the bladder and external urethral sphincter. During this event functional urinary obstruction and high intravesical pressure... 

Treatment modalities such as clean intermittent catheterization, surgical continence procedures, bladder augmentation, and the use of artificial urinary sphincters in addition to pharmacological treatment have significantly improved the quality of life for neurourologically impaired children. Since... 

Stein R, Wiesner C, Beetz R et al (2005b) Urinary diversion in children and adolescents with neurogenic bladder the Mainz experience - Part 11 Continent cutaneous diversion using the Mainz pouch 1. Pediatr Nephrol 20 926-931... 

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