The causes of indwelling urinary catheter leakage are complex and tricky to deal with, clinically it is important to assess the patient's bladder function in a timely and comprehensive manner, with the help of urodynamic examination, to find out the causes and take appropriate measures.

After indwelling urinary catheter, quiet state, the bladder is full without clamping the urinary catheter or clamping the urinary catheter, urine naturally seeps out along the urethral orifice, the emergence of the phenomenon of "pants wetting" or "bedwetting" can be judged to be urinary leakage.

Reason 1: Catheter obstruction, poor drainage
1.Analysis
Due to the patient's improper position or improper placement of the drainage bag, resulting in urethral distortion, pressure, folding, as well as acute bacterial infections, turbid urine, impurity precipitation or blood clot blockage.

2.Nursing countermeasures
Patients with indwelling urinary catheter should check the catheter frequently for pressure and distortion, and the position of drainage bag must be located 50cm below the bladder.
For patients with long-term indwelling urinary catheters, bladder flushing or replacement of urinary catheter should be carried out as soon as sediment is found. If necessary,[6] 100-200ml of sodium bicarbonate should be used to flush the bladder to prevent calcium deposition, or oral sodium bicarbonate tablets should be taken to alkalize the urine to reduce mucus secretion, and to keep the urinary catheter drainage smooth to stop the formation of urinary scale.

Cause 2: bladder spasm
Bladder spasms are mainly caused by overactive bladder and urine leakage. Overactive bladder is a group of urinary frequency, urgency and urge incontinence syndromes caused by unstable contraction of the detrusor muscle due to non-neurogenic factors and hyperreflexia of the detrusor muscle due to neurogenic factors.

The contraction of bladder detrusor muscle is controlled by cholinergic receptors, and tolterodine tartrate is a class of competitive M cholinergic receptor blockers, which can effectively inhibit the involuntary rhythmic contraction of the bladder [10]. However, the application of anticholinergic drugs should be aware of the adverse effects of the drugs.

The smaller the catheter model, the finer the diameter of the tube and the less irritation to the urethral mucosa and bladder neck.

Cause 3: Pathophysiologic factors
1.Analysis
This kind of patients due to physiological degenerative changes and lead to leakage of urine, common in the elderly and long-term bed-ridden patients, the common causes are urethral sphincter relaxation, prostate hyperplasia, bladder structure, capacity changes, and constipation leading to increased intravesical pressure.

2.Nursing countermeasures  
①Choose the appropriate urinary catheter
②Patients with urethral sphincter relaxation should strengthen the pelvic floor muscle training either actively or passively.
③ Solve the problem of constipation.

Reason 4: Inappropriate amount of water injection in the balloon
1.Analysis
When indwelling urinary catheterization, the amount of airbag injection is directly related to the occurrence of urine leakage. If the injection volume is too small, the incidence of urine leakage and detubation increases significantly [17]. When the injection volume of the balloon is too much, the pressure of the balloon on the internal urethral orifice and the bladder neck is too great, which will easily lead to bladder spasm and make the patient feel the sensation of urination, and then force the patient to urinate from time to time and lead to the occurrence of urinary leakage.

2.Nursing countermeasures
After choosing the appropriate type of urinary catheter and eliminating the objective factors related to urine leakage, the focus is on adjusting the amount of water injected into the balloon.