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Suprapubic Catheterisation - Emergency Medicine Exam Notes

Definition

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Relevant Anatomy

• The bladder lies in the retropubic space behind the symphysis pubis.
• When distended (>300 mL), it rises above the pubic symphysis as an extraperitoneal structure - the peritoneal reflection is pushed cephalad. This creates a safe "window" for percutaneous access without entering the peritoneum.
• The insertion point is 2-3 cm above the pubic symphysis in the midline, exploiting this extraperitoneal space.
• Key structures at risk: bowel (if bladder not adequately distended), inferior epigastric vessels (stay midline), peritoneum.

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Indications

Emergency Indications

Elective Indications

• Long-term bladder drainage in neurogenic bladder (spinal cord injury, MS, diabetic neuropathy)
• Chronic urinary retention when patient cannot void
• Preference over urethral catheter for comfort or nursing reasons

"In general, any patient requiring a urethral catheter, but in whom a catheter cannot be safely passed, is a candidate for a suprapubic cystostomy tube." - Roberts and Hedges' Clinical Procedures in Emergency Medicine, p.1333

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Contraindications

Absolute

• Non-distended or non-palpable bladder (< ~300 mL) - most important - risk of bowel/vessel injury is unacceptably high without a clear target. This is the #1 exam answer.
• Suspected bladder cancer - risk of tumour seeding along the tract
• Uncooperative patient (unable to achieve still positioning)

Relative

• Coagulopathy or uncorrected bleeding diathesis (correct first if possible)
• Previous lower abdominal/pelvic surgery (adhesions, bowel may be interposed in the retropubic space)
• Prior abdominal irradiation
• Concurrent antithrombotic therapy
• Pelvic anatomic abnormality from cancer or trauma

Key exam point: "The absence of an easily palpable or ultrasonographically localised distended urinary bladder is an absolute contraindication." (Medscape/eMedicine)

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Equipment

• Sterile preparation: povidone-iodine, sterile drape, gloves, mask
• Local anaesthetic: 10 mL lidocaine 1-2%, 10 mL syringe, 22-gauge spinal needle
• No. 11 or No. 15 scalpel blade
• Suprapubic catheter kit - several options:
  • Bonnano catheter (Becton-Dickinson) - pigtail self-retaining tip
  • Stamey percutaneous set (Cook Medical) - Malecot tip with wings
  • SupraFoley introducer (Rusch/Teleflex Medical)
  • Cook peel-away sheath (Chiou Suprapubic Kit) - uses Seldinger technique, preferred for ED use
• Guidewire (for Seldinger technique)
• Foley catheter (for Seldinger/peel-away approach)
• Closed urinary drainage bag
• 2-0 nylon suture to secure catheter
• Bedside ultrasound (strongly recommended)

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Pre-Procedure

1. Informed consent - explain indications, alternatives, risks
2. Warn patient: mild-to-moderate suprapubic discomfort for hours to days post-procedure
3. Confirm bladder is distended - by palpation and/or ultrasound (>300 mL needed)
4. If bladder not palpable due to obesity: ultrasound mandatory; if still unclear, consider cystoscopy or delay procedure
5. Review coagulation status; correct if needed

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Technique (Step-by-Step)

Method 1: Trocar/Obturator Technique (Traditional - Pfenninger & Fowler)

1. Position: Patient supine.
2. Sterile prep: Clean suprapubic skin with antiseptic; sterile drape.
3. Local anaesthesia: Infiltrate skin, subcutaneous tissue, fascia, and down to the bladder dome at a point 5 cm above the pubic symphysis in the midline. Aspirate before each injection.
4. Skin incision: Make a 1 cm horizontal skin incision at the anaesthetic site (some also incise the anterior rectus fascia).
5. Bladder confirmation (optional but recommended): Pass a 22-gauge spinal needle into the bladder to verify location and confirm urine return before inserting the trocar. If bladder is not distended enough, fill with sterile saline via this needle.
6. Assemble catheter: Place the metal obturator through the catheter lumen so the sharp tip extends beyond the catheter tip.
7. Insert: Advance the obturator + catheter through the incision at a 60-degree caudal angle (toward the bladder neck / mid-perineum) with firm pressure. Pass through rectus sheath, muscle, and into the bladder dome (~5 cm below skin in adults).
8. Advance a further 5 cm to ensure correct positioning.
9. Remove obturator: Urine will drain. The Malecot wings expand OR the Bonnano pigtail coils to self-retain. If balloon-type: inflate the balloon with sterile saline.
10. Secure catheter: Suture to skin with 2-0 nylon. Connect to closed drainage system.

Method 2: Seldinger (Guidewire) Technique - Preferred for Emergency Department

1. Prep and drape skin - sterile technique.
2. Inject local anaesthetic 2-3 cm above the pubic symphysis in the midline.
3. Confirm bladder by palpation or ultrasound. Advance a 22-gauge spinal needle with attached syringe, aspirating continuously until urine returns.
4. Remove syringe; thread guidewire through the needle into the bladder.
5. Remove needle, leaving guidewire in place.
6. Make a small stab incision at the skin-guidewire interface.
7. Pass the peel-away sheath + fascial dilator over the wire into the bladder.
8. Remove the guidewire and fascial dilator, leaving the sheath.
9. Pass a Foley balloon catheter through the sheath; inflate the balloon.
10. Withdraw (peel away) the sheath, leaving the Foley in the bladder.

"Among the most user-friendly devices for suprapubic bladder access is the Cook peel-away sheath unit. It uses the Seldinger technique to gain bladder access and allows suprapubic placement of a Foley balloon catheter for definitive bladder drainage. This device is readily suitable for ED use." - Roberts and Hedges', p.1332

Emergency shortcut: Any central venous catheter kit can be inserted suprapubically using the Seldinger technique when no dedicated SPC kit is available.

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Needle Angulation - Key Exam Point

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Complications

Immediate

Early

Delayed

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Ultrasound Guidance

• Strongly recommended in all cases, mandatory when:
  • Bladder not clinically palpable (obesity, etc.)
  • Previous lower abdominal surgery
  • Pelvic anatomic abnormalities
• Reduces bowel perforation rate from ~2.4% to 0.3%
• Confirms adequate bladder volume before insertion
• Image-guided insertion at a dedicated centre: bowel perforation rate 0.3% (Grainger & Allison's Diagnostic Radiology, p.2178)
• CT guidance indicated for complex pelvic anatomy (prior surgery, congenital abnormalities)

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Catheter Changing / Exchange

• Speed is critical when changing an established suprapubic catheter
• New catheter must be inserted within 5-10 minutes of removing the old one - the tract closes rapidly
• Never remove a suprapubic catheter unless you are ready to replace it immediately
• Use an exchange wire technique if needed; appropriate dilators can upsize to a permanent catheter

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Comparison: Suprapubic vs Urethral Catheter

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Key High-Yield Exam Points Summary

1. Absolute contraindication: non-distended / non-palpable bladder - risk of bowel perforation
2. Most common emergency indication: urethral trauma (pelvic fracture), acute retention where urethral route fails
3. Insertion site: 2-3 cm (Roberts & Hedges) or 5 cm (Pfenninger - traditional trocar) above pubic symphysis, midline
4. Angle in adults: caudal (toward bladder neck); in infants: perpendicular
5. Seldinger technique preferred in ED (Cook peel-away sheath)
6. Always use ultrasound when bladder not palpable
7. Bladder cancer = absolute contraindication (tract seeding risk)
8. Coagulopathy = relative contraindication (correct first)
9. Post-obstructive diuresis: observe 2-3 hours post-procedure; admit if occurs
10. Catheter change: never remove without immediate replacement; tract closes in 5-10 minutes

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• Roberts and Hedges' Clinical Procedures in Emergency Medicine, Chapter 55 (Suprapubic Cystostomy), pp.1332-1334
• Pfenninger and Fowler's Procedures for Primary Care, 3rd ed., Chapter 113, pp.809-812
• Grainger & Allison's Diagnostic Radiology, Chapter 85, p.2178 (image-guided insertion)
• StatPearls: Suprapubic Bladder Catheterization (NCBI)