Leakage Associated With Urinary Catheter Usage

Robert Theriault, BSN, RN; Peggy Ward-Smith, PhD, RN; Charles Soper, MB, MRCP

Disclosures

Urol Nurs. 2012;32(6):307-312. 

In This Article

A Conceptual Approach to the Cause and the Management of Catheter Leakage

Catheter leakage associated with occlusion of the catheter lumen due to encrustation, debris, blood clots, or kinked drainage tube has been identified in the literature. It has not yet been possible to correlate indwelling bladder cathe ter leakage with bladder spasms. One aim of this article is to begin to bridge this knowledge gap. The result of the literature review provides hypotheses related to indwelling bladder catheter leakage and bladder spasms, but the suggested methods of managing this problem have not undergone rigorous testing. These data are needed to provide evidencebased care, rather than treatment that is based on trial and error.

The authors hypothesize that one cause of indwelling urinary catheter leakage when associated with bladder spasms has yet to be identified. Thus, the authors hypothesize that a modification in bladder catheter design will alleviate this adverse effect. It is hoped that health professionals involved in research and medical device companies will consider this new concept in their research.

Normal Bladder Physiology

It is important to acknowledge that air is never normally present inside the bladder. Diagrams within health literature generally provide images of a catheterized bladder showing urine in the lower half and air in the upper half (Cruickshank & Woodward, 2001; Getliffe & Dolman, 2003; Nazarko, 2010). These diagrams suggest that urine drains through the catheter lumen and is replaced by air. This is not accurate; anatomy documents by Tortora and Grabowski (2008) demonstrate that an empty bladder is collapsed on itself. When empty, the bladder is then not hollow, and thus, cannot contain air.

Physiology of a Catheterized Bladder

When an indwelling bladder catheter is present, the bladder is unable to collapse entirely, prevented by the presence of the catheter tip and balloon. A pool of urine remains around a catheter within a free drainage system. Because an emptying bladder collapses on itself, the catheter tip, within a free drainage catheter system, does not remain straight. When the bladder deflates, its volume shrinks until it touches the catheter tip, resulting in a kink. The two catheter eyes are then occluded (see Figure 1). It is suggested that this enforced kinking of the catheter tip is the fundamental cause of leakage associated with bladder spasms. It is also suggested that when a urethral catheter is used, the pressure of organs above the bladder, called abdominal pressure in urodynamics, keeps the catheter tip kinked even as the bladder fills. In this case, the bladder volume increases horizontally but not vertically because the abdominal pressure prevents the bladder from lifting during the filling phase. When a detrusor contraction occurs, the only way for urine to be excreted is between the catheter shaft and the urethra mucosa because the catheter tip is kinked, blocking the eyes. This is usually accompanied by painful bladder contractions due to extra effort from the bladder to evacuate the urine. When the urethra is very tight around the catheter, contractions of the bladder can be ineffective in expulsing the urine. This results in an acute retention, which requires urgent intervention( s).

Figure 1.

Empty Bladder Collapses on Itself and Occludes the Two Catheter Eyes

The authors have clinically determined that changing the catheter site from urethral to suprapubic usually diminishes or prevents leakage. In a suprapubic placement, the catheter tip is positioned horizontally, which is then not affected by the abdominal pressure. However, even in the presence of a suprapubically placed catheter, leakage can occur when the bladder becomes small and atrophic, and in the opinion of these authors, does not provide enough space for the catheter tip to remain straight.

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