Can coughing change pressure in the bladder to move clots in unwell patients with a urinary (g) catheter?

Coughing Can Effectively Dislodge Bladder Catheter Clots in Unwell Patients

Yes, coughing can effectively change pressure in the bladder to help dislodge clots in urinary catheters of unwell patients. This physiological mechanism can be utilized as a non-invasive intervention for catheter occlusion.

Physiological Mechanism

Coughing creates significant changes in intrathoracic and intra-abdominal pressures that can be transmitted to the bladder:

• During vigorous coughing, intrathoracic pressures of up to 300 mm Hg and expiratory velocities of up to 28,000 cm/s can be generated 1
• Coughing involves a compressive phase characterized by contraction of thoracic and abdominal musculature against a fixed diaphragm 1
• The expiratory phase consists of rapid expulsion of air when the glottis opens, creating pressure changes throughout the thorax and abdomen 1
• These pressure changes are transmitted to the bladder, potentially dislodging clots that may be occluding a urinary catheter

Clinical Application for Catheter Clots

For unwell patients with clotted urinary catheters, a stepwise approach is recommended:

1. Coughing maneuver (first-line):

   • Have the conscious patient perform several forceful coughs
   • Similar to "cough CPR," this increases intrathoracic pressure and can generate systemic pressure changes 1
   • The transmitted pressure may dislodge small to moderate clots obstructing the catheter

2. If coughing is unsuccessful, proceed to:

   • Manual irrigation with normal saline using a 60-mL syringe 2
   • Chemical dissolution options:
     • Hydrogen peroxide solution (successful in 27 of 31 patients in one study) 3
     • Chymotrypsin in sodium bicarbonate solution (successful in 19 of 22 patients) 2

3. For severe clot retention resistant to above measures:

   • Consider larger bore catheters (28-32F rectal catheter has shown success) 4
   • Thoracic catheter technique for tenacious clots 5

Important Considerations

• Coughing is most effective in conscious patients who can generate sufficient force
• The effectiveness depends on the size and adherence of the clot
• Patients with respiratory compromise may not generate adequate pressure
• Excessive coughing can cause complications including:
  • Cardiovascular stress
  • Increased intracranial pressure
  • Musculoskeletal strain 1

Monitoring for Catheter-Related Thrombosis

Be vigilant for signs of catheter-related thrombosis, which can complicate management:

• Difficulty aspirating or infusing through the catheter lumen
• Local pain or burning sensation during injection
• Redness, swelling, and edema 1
• If suspected, Doppler ultrasound is the recommended diagnostic approach 1

For unwell patients with urinary catheters, coughing represents a simple, non-invasive first-line intervention that can effectively change bladder pressure to dislodge clots before resorting to more invasive techniques.