From the Guidelines
An indwelling urinary catheter (IUC) may not drain properly due to mechanical obstruction, blockage by blood clots or mucus plugs, encrustation, bladder spasms, insufficient fluid intake, constipation, or urinary tract infections. The causes of improper drainage can be multifactorial and should be systematically evaluated. Mechanical obstruction can occur from kinking of the tubing, compression of the catheter by the patient's body position, or the catheter tip being positioned above the level of urine in the bladder 1.
Common Causes of Improper Drainage
- Mechanical obstruction: kinking of the tubing, compression of the catheter, or catheter tip positioned above the level of urine in the bladder
- Blockage by blood clots, mucus plugs, or sediment
- Encrustation from mineral deposits, particularly in patients with alkaline urine
- Bladder spasms causing the catheter tip to be drawn against the bladder wall
- Insufficient fluid intake leading to concentrated urine that flows poorly
- Constipation or fecal impaction externally compressing the catheter
- Urinary tract infections producing thick, cloudy urine that clogs the catheter
To address these issues, ensure the catheter and tubing are not kinked or compressed, maintain adequate hydration (typically 1.5-2 liters daily unless contraindicated), consider gentle irrigation with sterile saline if blockage is suspected, reposition the patient to optimize drainage, and evaluate for signs of urinary tract infection 1. If these measures fail, catheter replacement may be necessary, particularly if encrustation or persistent blockage is present. Institution-specific strategies should be developed to minimize disconnection of the catheter junction and ensure the drainage bag and connecting tube are always kept below the level of the bladder 1.
From the Research
Causes of Indwelling Urinary Catheter (IUC) Not Draining Properly
- Catheter blockages: blockages can occur due to various reasons such as encrustation, blood clots, or other debris 2
- Encrustation: mineral deposits can form on the catheter, causing it to become blocked 2
- Negative pressure: if the catheter is not properly secured, negative pressure can cause the catheter to become blocked 2
- Bladder spasm: bladder spasms can cause the catheter to become kinked or blocked 2
- Trauma: trauma to the catheter or the surrounding tissue can cause the catheter to become blocked or damaged 2
- Paraphimosis: in men, paraphimosis can occur if the catheter is not properly secured, causing the catheter to become blocked 2
- Bacterial growth: bacterial growth in the catheter or the urine can cause the catheter to become blocked or infected 3, 4, 5, 6
- Biofilm formation: biofilm can form on the catheter, providing a habitat for bacteria to grow and cause infection 4
Prevention and Management
- Proper aseptic practices for catheter insertion and maintenance can help prevent complications 3, 4, 5, 6
- Use of a closed catheter collection system can help prevent bacterial growth and infection 3, 4
- Regular monitoring and maintenance of the catheter can help identify and address any issues promptly 2
- Use of intervention bundles and collaboratives can help implement effective prevention measures 3, 6