• Choose a category
• All
• Classic-Fiction

© 2000 Norgine Ltd.

Urinary elimination

Definition

Urinary elimination is the excretion of urine from the body (Thibodeau and Patton 2007a).

Anatomy and physiology

The urinary tract (Figure 6.2) consists of the two kidneys, two ureters, the bladder and urethra. The urinary system produces, stores and eliminates urine. The kidneys are responsible for excreting wastes such as urea and ammonium and for the reabsorption of glucose and amino acids. They are involved with the production of hormones including calcitrol, renin and erythropoietin. The kidneys also have homoeostatic functions including the regulation of electrolytes, acid/base balance and blood pressure (Tortora and Derrickson 2009).

Figure 6.2 Anatomy of the genitourinary tract (female).

Each kidney excretes urine into a ureter, which arises from the renal pelvis on the medial aspect of each kidney. In adults the ureters are approximately 25–30 cm long and 2–4 mm in diameter (Tortora and Derrickson 2009). The ureters are muscular tubes, which propel urine from the kidneys to the urinary bladder. They enter the bladder through the back of the bladder, running within the wall of the bladder for a few centimetres. Ureterovesical valves prevent the backflow of urine from the bladder to the kidneys.

The bladder sits on the pelvic floor and is a hollow, muscular, distensible organ which stores urine until it is convenient to expel it. Urine enters the bladder via the ureters and exits via the urethra. As the bladder fills, stretch receptors in the muscular wall signal the parasympathetic nervous system to contract the bladder, initiating the conscious desire to expel urine. In order for urine to be expelled, both the automatically controlled internal sphincter and the voluntary controlled external sphincter must be opened.

Urine leaves the bladder via the urethra. In females this lies in front of the anterior wall of the vagina and is approximately 3.8 cm long. In males it passes through the prostate and penis and is approximately 20 cm long (Tortora and Derrickson 2009).

Penile sheaths

Definition

Penile sheaths are external devices made from a soft and flexible latex or silicone tubing which are applied over the penis to direct urine into a urinary drainage bag from where it can be conveniently emptied. They are used by men to manage urinary incontinence.

Evidence-based approaches

Rationale

Penile sheaths (also known as conveens) are only to be considered once other methods of promoting continence have failed, as the promotion and treatment of incontinence should be the primary concern of the nurse (Pomfret 2003). They should be considered as a preferable alternative to other methods of continence control, such as pads which quickly can become sodden (Pomfret 2003) and cause skin problems, and catheters, which have several potential complications (Fader et al. 2001).

Indications

Penile sheaths may be used to relieve incontinence when no other means is practicable or when all other methods have failed. Penile sheaths are associated with many common problems which are identified by Woodward (2007); these include difficulty in fitting, leaking, kinking, falling off, allergies and urinary tract infections.

Contraindications

Penile sheaths are contraindicated for men with very small or retracted penises (Booth 2009).

Preprocedural considerations

Equipment

Silicone types are now preferred due to concerns about latex allergies (Booth and Lee 2005) (Figure 6.3).

Figure 6.3 Penile sheath.

Sizing and fitting

As modern sheaths come in a variety of sizes and the correct size can be determined by measuring the girth of the penile shaft, one of the most important considerations is to move away from the mentality that one size fits all. The penis should be measured in the flaccid state (Potter 2007). Most devices come with a manufacturer’s sheath sizing guide with different diameters cut into it, so that the correct size can be easily determined. Sheaths are available in a variety