Ver el código de «Purple urine bag syndrome»

==Background==
*Rare phenomenon characterized by purple discoloration of the urinary drainage bag and tubing
*Benign reaction in itself, but indicates high bacterial load and [[UTI|Catheter-associated urinary tract infection]]
*Predominantly affects chronically catheterized, constipated, elderly females (often in nursing homes)
*Caused by specific Gram-negative bacteria producing sulphatase and phosphatase enzymes[ncbi.nlm.nih.gov]

==Pathophysiology==
*'''Mechanism:'''
**Dietary Tryptophan is metabolized by gut bacteria into Indole
**Indole is absorbed and converted to Indoxyl sulfate in the liver
**Indoxyl sulfate is excreted into urine
**Bacteria producing '''indoxyl sulfatase''' or phosphatase catalyse the breakdown of indoxyl sulfate into:
***'''Indigo''' (Blue pigment)
***'''Indirubin''' (Red pigment)
** pigments interact with the polyvinyl chloride (PVC) of the catheter bag to create a 
*'''Risk Factors:'''
**Chronic Indwelling Catheter (PVC material)
**[[Constipation]] (Prolonged gut transit increases bacterial deamination of tryptophan)
**Alkaline Urine (Favors pigment precipitation)
**High bacterial load
**Female gender (shorter urethra, higher UTI risk)

==Clinical Features==
[[File:Purple urine bag syndrome.jpg|thumb|Purple urine bag syndrome in a 90 year old patient with urinary tract infection.]]
*[[Altered Mental Status]] (if associated with symptomatic UTI/Sepsis)
*Visual alarm (Patient/family/staff often distressed by bright purple color)
*Otherwise usually asymptomatic regarding the discoloration itself
*Common causative organisms (Sulfatase/Phosphatase producers):
**[[Providencia stuartii]]
**[[Providencia rettgeri]]
**[[Klebsiella pneumoniae]]
**[[Proteus mirabilis]]
**[[Escherichia coli]]
**[[Morganella morganii]]
**[[Pseudomonas aeruginosa]]

==Differential Diagnosis==
*[[Hematuria]] (Red/Brown)
*[[Rhabdomyolysis]] (Tea-colored)
*[[Porphyria]] (Port-wine colored)
*Medication/Dietary inputs:
**[[Methylene blue]]
**[[Rifampicin]] (Orange/Red)
**Beets/Blackberries
**Phenolphthalein (laxatives)

==Evaluation==
*[[Urinalysis]]
**Typically '''Alkaline pH''' (> 7.0)
**Pyuria/Leukocyte esterase positive
*[[Urine Culture]]
**Mandatory to guide susceptibility (high resistance rates in this population)
*[[Basic Metabolic Panel|Renal function]]
**Check for AKI/Dehydration
*Evaluate for [[Sepsis]]
**Hypothermia/Fever, Hypotension, Tachycardia

==Management==
*'''Reassurance'''
**Explain the benign chemical nature of the discoloration to patient/caregivers
*Source Control
**Exchange the urinary catheter (mandatory to remove biofilm and stained plastic)
**Crucial to reduce gut production of indole
*Antibiotics
**Based on clinical status:
***'''Asymptomatic Bacteriuria:''' Antibiotics generally ''not'' indicated solely for purple bag; focus on hygiene/catheter exchange
***'''Symptomatic CAUTI/Sepsis:''' Empiric broad-spectrum coverage covering Gram-negatives (e.g., [[Cefepime]], [[Piperacillin-Tazobactam]]) until sensitivities return
**Note: Many causative organisms (Example: ''Providencia'', ''Morganella'') have intrinsic resistance to common agents like Nitrofurantoin or Colistin

==See Also==
*[[Colored urine]]
*[[Urinary Tract Infection]]
*[[Providencia stuartii]]
*[[Morganella morganii]]

==References==
<references/>

[[Category:Urology]]
[[Category:Geriatrics]]
[[Category:ID]]