What are the causes of urinary retention in a trauma patient?

From the Guidelines

Urinary retention in trauma patients is most commonly caused by neurogenic factors, such as spinal cord injury, mechanical obstruction, or medication effects, including opioids and anticholinergics. The management of urinary retention in trauma patients should prioritize the prevention of complications such as urinary tract infections, bladder rupture, and renal dysfunction. According to the most recent guidelines, including the urotrauma guideline 2020 by the American Urological Association 1, the management of urogenital trauma should focus on restoring homeostasis and normal physiology.

The causes of urinary retention in trauma patients can be multifactorial, including:

• Neurogenic causes, such as spinal cord injury
• Mechanical obstruction, such as urethral injury or bladder rupture
• Medication effects, including opioids and anticholinergics
• Other factors, such as pain, anxiety, or immobilization

The World Society of Emergency Surgery (WSES) and the American Association for the Surgery of Trauma (AAST) guidelines on kidney and uro-trauma management 1 emphasize the importance of a multidisciplinary approach to managing urogenital trauma, including the use of imaging studies, such as CT scans and retrograde urethrocystography, to diagnose and manage lower urinary tract injuries.

In patients with suspected urethral injury, a retrograde urethrogram should be performed before catheterization to avoid worsening injury, as recommended by the guidelines on early management of severe pelvic injury 1. The use of alpha-blockers, such as tamsulosin or alfuzosin, may be considered prior to attempted catheter removal in patients with urinary retention, as suggested by the AUA guideline on management of benign prostatic hyperplasia 1.

Overall, the management of urinary retention in trauma patients requires a comprehensive approach that addresses the underlying cause of retention, provides immediate drainage, and prevents complications. Prompt bladder catheterization, typically using a Foley catheter, is essential to monitor urine output, prevent bladder distension, and assess for hematuria indicating genitourinary trauma.

From the FDA Drug Label

In urinary retention, if the sphincter fails to relax as bethanechol chloride contracts the bladder, urine may be forced up the ureter into the kidney pelvis.

The cause of urinary retention in a trauma patient is not directly addressed in the provided drug labels. However, one possible cause of urinary retention is the failure of the sphincter to relax, allowing the bladder to contract and potentially forcing urine up the ureter into the kidney pelvis 2.

• Key points:
  • Failure of the sphincter to relax may cause urinary retention.
  • This can lead to urine being forced up the ureter into the kidney pelvis.
  • The provided drug labels do not directly address the causes of urinary retention in trauma patients.

From the Research

Causes of Urinary Retention in Trauma Patients

• Trauma can cause urinary retention due to various factors, including:
  • Structural damage to the urinary tract 3
  • Neurologic damage or impairment 3
  • Infection or sepsis 3
  • Medication or toxicologic effects 3
• In critically ill trauma patients, factors that may contribute to urinary retention include:
  • Male gender 4
  • Orthopedic trauma 4
  • Anesthesia 4
  • Use of paralytics 4
  • Multiple operative interventions 4
• Other possible causes of urinary retention in trauma patients include:
  • Obstructive causes, such as benign prostatic hyperplasia or prostatitis 5
  • Infectious or inflammatory causes, such as cystitis or urethritis 5
  • Pharmacologic causes, such as anticholinergic or alpha-adrenergic agonist medications 5
  • Neurologic causes, such as cortical, spinal, or peripheral nerve lesions 5

Specific Considerations in Trauma Patients

• Trauma patients with artificial urinary sphincters may experience urinary retention due to malfunction or improper use of the device 6
• Bedside renal ultrasound can be useful in diagnosing hydronephrosis and hydroureter in trauma patients with urinary retention 6
• Prompt urology consultation is recommended in cases of urinary retention in trauma patients, especially those with complex or unusual causes 6