The correct choice of urinary catheter directly influences patient safety, comfort during the procedure, and the risk of complications such as urinary tract infections, urethral trauma, and the need for new interventions.
Although often confused, the Foley Catheter (indwelling) and the Intermittent Catheter (intermittent urethral) have completely different indications. Using the inappropriate model can compromise care and increase patient risks.
Comparison: Foley Catheter × Intermittent Catheter
| Characteristic | Foley Catheter | Intermittent Catheter |
|---|---|---|
| Duration | Long-term indwelling | Temporary use |
| Retention balloon | Yes | No |
| Number of lumens | 2 or 3 lumens | Single lumen |
| Retention after drainage | Remains in place | Removed after procedure |
| Main purpose | Continuous drainage | Immediate bladder emptying |
| Requires collection bag | Yes | Normally not |
| Risk of infection | Higher when maintained for long periods | Lower when used correctly |
| Usage | Hospital, ICU, post-op, Home Care | Clinics, emergency care, inpatient and specific procedures |
Foley Catheter
The Foley Catheter is an indwelling device indicated when continuous urinary drainage is needed for prolonged periods. It has an inflatable balloon responsible for keeping it positioned inside the bladder.
Advantages
- Continuous drainage
- Lower risk of displacement
- Allows monitoring of urine output
- Available in two-way and three-way versions
Limitations
- Higher risk of infection when used for prolonged periods
- Requires a collection bag
- Requires aseptic technique for insertion
Main applications
- Post-operative
- Critical patients
- ICU
- Prolonged urinary retention
- Home Care
Intermittent Catheter
The Intermittent Catheter is intended for intermittent bladder catheterization, remaining only as long as necessary to empty the bladder. After the procedure, the catheter is removed.
Advantages
- Quick procedure
- Shorter dwell time
- Lower risk of infection when used correctly
- Greater comfort for specific procedures
Limitations
- Not indicated for continuous drainage
- Requires re-insertion when new drainage is needed
Main applications
- Acute urinary retention
- Sterile urine collection
- Intermittent catheterization
- Assessment of post-void residual
When to Use Each One?
| Clinical situation | Indicated catheter |
|---|---|
| Acute urinary retention | Intermittent Catheter |
| Continuous monitoring of urine output | Foley Catheter |
| Post-operative | Foley Catheter |
| Sterile urine collection | Intermittent Catheter |
| Intermittent catheterization | Intermittent Catheter |
| Bedridden patient for a long period | Foley Catheter |
| ICU monitoring | Foley Catheter |
Quick Guide by Setting
| Setting | Most used catheter |
|---|---|
| Consultation room | Intermittent Catheter |
| Outpatient clinic | Intermittent Catheter |
| Hospital | Foley Catheter |
| Operating room | Foley Catheter |
| ICU | Foley Catheter |
| Home Care | Foley Catheter |
| Emergency care | Intermittent or Foley, as indicated |
Myths and Facts
| Statement | Myth or Fact? | Explanation |
|---|---|---|
| All urinary catheters have a balloon. | Myth | Only the Foley Catheter has a retention balloon. |
| The Intermittent Catheter must remain in place. | Myth | It is removed after drainage. |
| The Foley allows continuous drainage. | Fact | This is its main indication. |
| The longer the catheterization time, the greater the risk of infection. | Fact | The risk increases with catheter dwell time. |
| Catheter choice depends only on the size. | Myth | It also depends on the purpose and dwell time. |
Most Common Errors
| Error | Recommended action |
|---|---|
| Using a Foley when the procedure is only intermittent | Assess if the Intermittent Catheter meets the clinical indication |
| Not inflating the Foley balloon correctly | Follow manufacturer's instructions |
| Choosing inadequate size | Select according to clinical assessment |
| Maintaining a Foley without clinical indication | Remove as early as possible |
| Disregarding aseptic technique | Follow institutional protocols |
Technical Glossary
| Term | Definition |
|---|---|
| Bladder catheterization | Introduction of a catheter into the bladder for urinary drainage. |
| Foley | Indwelling bladder catheter with a retention balloon. |
| Intermittent catheterization | Temporary introduction of the catheter for bladder emptying. |
| Balloon | Inflatable chamber that secures the Foley in the bladder. |
| Urine output | Volume of urine eliminated over a certain period. |
Frequently Asked Questions
Can the Foley Catheter be used just to collect urine?
Yes, but typically the Intermittent Catheter is the more appropriate option when continuous drainage is not needed.
Does every Foley Catheter have a balloon?
Yes. The balloon is the feature that allows its retention in the bladder.
Can the Intermittent Catheter remain in place?
No. It should be removed after bladder drainage, except in specific situations defined by the care protocol.
How to choose the correct size?
The choice depends on the patient's age, sex, anatomy, and clinical indication, always according to the healthcare professional's assessment.
Checklist Before Purchase
- Does the procedure require continuous drainage?
- Is the indication solely for bladder emptying?
- Is the size appropriate for the patient?
- Will a collection bag be needed?
- Does the product have regular registration with ANVISA?
- Does the material comply with the institution's protocol?
Technical Standards
- NR-32 – Occupational Safety and Health in Healthcare Services
- ANVISA RDC No. 36/2013 – Patient Safety in Healthcare Services
- ANVISA RDCs applicable to regularized medical devices
- Institutional protocols for preventing Catheter-Associated Urinary Tract Infection (CAUTI)
- Recommendations from the Hospital Infection Control Commission (CCIH)
Conclusion
The difference between the Foley Catheter and the Intermittent Catheter goes far beyond the presence of a balloon. Each device was developed for a specific purpose, and its choice must consider the objective of catheterization, the estimated duration of use, and the patient's clinical conditions. Selecting the correct catheter contributes to safer care, reduces complications, and promotes care aligned with best practices and institutional protocols.
