Mnemonic: Causes of Acute Urinary Retention

I still remember how a junior med student had submitted a History and Physical assignment on a lady patient using a standard template going around in medical school, but had forgotten to edit out the “prostate exam normal” part. Attending asked him if he had examined the patient’s husband instead. 🤣
Acute Urinary Retention (AUR) is commonly seen in inpatients – especially in those with prostates – but not uncommon in ladies, and can be asymptomatic in the elderly. Not everyone needs a Foley catheter immediately, but if they have a large volume retention ( > 1000 cc) or any retention with hydronephrosis or AKI, they are very likely to retain again and a Foley catheter maybe warranted right away.

Logically, retention is from either loss of bladder muscle power, excess bladder neck spasm or swelling or obstruction of outflow in urethra. Here are some benign triggers to remember & solve & prevent AUR that develop during inpatient stay. All The ‘P‘s associated with inability to Pee :

P – Pills (Meds like anticholinergics, Alpha-agonists, opioids, etc that relax the bladder or cause neck spasm )
P – Poop! Hard stool can press on the urethra. (Solve constipation with and without meds.)
P – Pee ! or Puffed up bladder: If urine gets held too long, bladder wall stretches too thin and reduces compressive power. This can be Intentional or Unintentional.
Intentional: Patents may withhold urinating if they are too weak, dizzy or in pain to walk to the bathroom or embarrassed to have a nurse to accompany them or pee in a bedside urinal.).
Unintentional: excess IV fluids, diuretics, sedated/confused , Alcohol diuresis, etc
P – Prostate: Enlargement / Cancer
P – Prolapse of Pelvic organs (bladder/rectal/vaginal)
P – Panic /anxiety: Sympathetic stimulation of the bladder neck causes contraction
P – Penile stricture or Phimosis
P – Pelvic nerve issues e.g. Cauda Quina or Pudendal nerve damage
P – Post-procedure trauma/bleed/clots including post-catheter
P – Procedural Anesthesia, especially General: Anesthetics numb nerves controlling the bladder. Foley cath is usually inserted during major surgery to monitor I & Os and to prevent AUR later. I like to leave the catheter in for at least 1-2 days post-op, esp if General anesthesia is used, and wait for patients to poop/mobilize before removal to reduce retention risk