Methylene Blue Preparation for Bladder Backfilling
To properly mix methylene blue for bladder backfilling, use a 0.04% solution by mixing one 10-mL ampule of 1% methylene blue with 240 mL of normal saline (0.9% sodium chloride). 1
Standard Preparation Method
- Start with a 10-mL ampule of 1% methylene blue solution as your base concentration 1
- Add this to 240 mL of normal saline (0.9% sodium chloride) to create a 0.04% solution that is appropriate for general bladder backfilling 1
- Ensure thorough mixing for uniform distribution of the dye throughout the solution 1
- The solution can be administered through a Foley catheter under 20 cm of hydrostatic pressure 2
- Allow approximately 5 minutes of contact time before draining the solution and washing the bladder with saline 2
Alternative Concentration Options
- For more targeted visualization of specific areas, a more concentrated solution may be prepared 1
- For a 0.2% concentration, mix one 10-mL ampule of 1% methylene blue with 40 mL of saline 1
- This concentrated solution can be applied directly to areas of interest using a 60-mL syringe through a catheter 1
- For bladder tumor identification, some studies have used 0.1% methylene blue in 0.9% saline with volumes up to 400 mL 2
Administration Technique
- Insert a Foley catheter into the bladder using sterile technique 2
- Instill the prepared methylene blue solution through the catheter 2
- For diagnostic procedures, maintain the solution in the bladder for approximately 5 minutes 2
- After the appropriate contact time, drain the solution completely 2
- Wash the bladder with normal saline to remove excess dye 2
- Proceed with the intended diagnostic or surgical procedure 2, 3
Clinical Applications
- Methylene blue is taken up by actively absorbing epithelial cells, enhancing visualization of certain tissues 4
- It can help identify bladder diverticula during surgical procedures 3
- The dye can assist in detecting fistulas by showing leakage from the bladder to other structures 5
- It can selectively stain bladder tumors without staining normal urothelium, aiding in endoscopic identification 2
Safety Considerations
- Be aware that methylene blue may cause a green hue to urine and stool for up to 24 hours 4, 1
- The stain typically persists until complete renal excretion or cellular loss 4
- In rare cases, high systemic doses of methylene blue (>7 mg/kg) can cause methemoglobinemia 4
- Use caution in patients with G6PD deficiency, as methylene blue may cause hemolytic anemia if absorbed systemically 4, 1
- Nonvisualization of methylene blue in urine may occur due to metabolism to colorless leukomethylene blue, not necessarily indicating anatomic issues 6
Procedural Tips
- Suction any excess solution after approximately 1 minute to aid visualization 1
- For intraoperative identification of bladder structures, instillation of methylene blue can help precisely identify anatomical features 3
- When checking for bladder integrity during surgical procedures, negative methylene blue extravasation indicates bladder integrity 5
- For optimal staining in diagnostic procedures, ensure complete contact of the solution with all bladder surfaces 2