Overview
Urosepsis
Topic Overview
Summary
Urosepsis is sepsis arising from a urinary tract infection (UTI). It is life-threatening and requires urgent recognition and treatment. It most commonly occurs with obstructed urinary tract (e.g., ureteric stone), indwelling catheters, or complicated UTI. Management is the Sepsis Six bundle, IV antibiotics, and urgent source control (e.g., nephrostomy or stent for obstructed infected kidney). Mortality is high if treatment is delayed.
Key Facts
- Definition: Sepsis from urinary tract source
- Common causes: Obstructing ureteric stone + infection, catheter-associated UTI
- Key principle: Infected obstructed system needs URGENT DRAINAGE
- Treatment: Sepsis Six + IV antibiotics + source control
- Mortality: 20-40% if septic shock develops
Clinical Pearls
Infected obstructed kidney = emergency — needs drainage (nephrostomy or stent)
A renal stone with fever = urosepsis until proven otherwise
Antibiotics alone will not work if system is obstructed
Why This Matters Clinically
Urosepsis is a common cause of sepsis, especially in elderly patients with catheters and patients with renal stones. Early antibiotics and source control save lives.
Visual Summary
Visual assets to be added:
- Urosepsis pathophysiology diagram
- CT showing infected hydronephrosis
- Sepsis Six bundle
- Source control options (nephrostomy vs stent)
Epidemiology
Incidence
- 20-30% of all sepsis cases arise from urinary tract
- Most common source of sepsis in elderly
Demographics
- Elderly
- Female (anatomical predisposition to UTI)
- Catheterised patients
- Patients with urological abnormalities
Risk Factors
| Factor | Notes |
|---|---|
| Urinary tract obstruction | Stone, tumour, BPH |
| Indwelling catheter | Major risk |
| Diabetes mellitus | |
| Immunocompromise | |
| Recent urological procedure | |
| Pregnancy | |
| Anatomical abnormality | Reflux, neurogenic bladder |
Pathophysiology
Mechanism
- UTI develops (ascending infection, catheter)
- Bacteria enter bloodstream (bacteraemia)
- Systemic inflammatory response → sepsis
- If obstructed, pus cannot drain → rapid deterioration
Common Organisms
| Organism | Frequency |
|---|---|
| E. coli | 50-70% |
| Klebsiella | 10-15% |
| Proteus | 5-10% |
| Pseudomonas | Catheter-associated |
| Enterococcus |
Why Obstruction is Critical
- Infected urine under pressure
- Cannot drain
- Renal parenchyma damaged
- Antibiotics cannot penetrate
- Needs mechanical drainage
Clinical Presentation
Symptoms
Signs
Sepsis Signs
Red Flags
| Finding | Significance |
|---|---|
| Known stone + fever | Infected obstructed system |
| Septic shock | Urgent resuscitation and source control |
| Immunocompromise | Higher mortality |
| Bilateral obstruction | AKI, critical |
Fever, rigors
Common presentation.
Loin/flank pain
Common presentation.
Dysuria, frequency (may be absent if obstructed)
Common presentation.
Nausea, vomiting
Common presentation.
Confusion (especially elderly)
Common presentation.
Clinical Examination
General
- Fever or hypothermia
- Tachycardia
- Hypotension
- Confusion
Abdomen/Loin
- Loin tenderness (pyelonephritis)
- Suprapubic tenderness
- Palpable bladder (retention)
Catheter
- Check for blockage
- Appearance of urine (cloudy, offensive)
Investigations
Blood Tests
| Test | Finding |
|---|---|
| FBC | WCC raised (or low in severe sepsis) |
| CRP | Elevated |
| U&E, creatinine | AKI common |
| Lactate | Elevated in sepsis |
| Blood cultures | Essential — before antibiotics if possible |
Urine Tests
| Test | Notes |
|---|---|
| Urinalysis | Leucocytes, nitrites, blood |
| Urine culture | Essential |
| Catheter specimen | If catheterised |
Imaging
| Modality | Indication |
|---|---|
| CT KUB non-contrast | Stone detection |
| CT abdomen with contrast | Best for hydronephrosis, abscess |
| Ultrasound | Hydronephrosis; bedside |
Key CT Findings
- Hydronephrosis
- Obstructing stone
- Perinephric stranding
- Renal abscess
Classification & Staging
By Source
| Source | Notes |
|---|---|
| Upper UTI | Pyelonephritis with sepsis |
| Obstructed system | Stone, tumour, stricture |
| Catheter-associated | CAUTI |
| Post-procedural | After urological intervention |
By Severity
- Sepsis
- Septic shock (hypotension despite fluids)
Management
Sepsis Six — Within 1 Hour
| Action | Details |
|---|---|
| Oxygen | Maintain SpO2 over 94% |
| Blood cultures | Before antibiotics |
| IV antibiotics | Broad-spectrum |
| IV fluids | 500mL crystalloid bolus |
| Lactate | Check |
| Urine output | Catheterise, measure hourly |
IV Antibiotics — Empirical
| Regimen | Notes |
|---|---|
| Piperacillin-tazobactam | Broad-spectrum |
| Gentamicin | (Check renal function, single dose often used) |
| Or meropenem | If ESBL risk |
| Adjust | Based on cultures |
Source Control — URGENT if Obstructed
| Procedure | Indication |
|---|---|
| Nephrostomy | Percutaneous; IR or urology |
| Ureteric stent (JJ) | Endoscopic |
| Catheter change/removal | CAUTI |
| Abscess drainage | If present |
Key: An infected obstructed system will NOT settle with antibiotics alone — needs drainage
Supportive Care
- ICU if shocked
- Vasopressors if needed
- Renal replacement therapy if AKI
Complications
Renal
- Renal abscess
- Perinephric abscess
- Pyonephrosis
- Renal scarring
Systemic
- Septic shock
- Multi-organ failure
- DIC
- Death
Prognosis & Outcomes
Mortality
- Urosepsis: 10-15%
- Uroseptic shock: 20-40%
Factors Affecting Outcome
- Time to antibiotics
- Time to source control
- Organism resistance
- Patient comorbidities
Evidence & Guidelines
Key Guidelines
- NICE NG51: Sepsis
- EAU Guidelines on Urological Infections
- Surviving Sepsis Campaign
Key Evidence
- Early antibiotics improve survival
- Source control is essential for obstructed systems
Patient & Family Information
What is Urosepsis?
Urosepsis is a serious infection that starts in the urinary tract (kidneys, bladder) and spreads to the bloodstream. It can make you very unwell.
Symptoms
- Fever and shivering
- Pain in your side or back
- Feeling confused
- Feeling very unwell
Treatment
- Antibiotics through a drip
- Fluids
- If blocked, a tube may be needed to drain the kidney
Resources
References
Primary Guidelines
- NICE. Sepsis: Recognition, Diagnosis and Early Management (NG51). 2016. nice.org.uk
- Bonkat G, et al. EAU Guidelines on Urological Infections. 2022.
Key Reviews
- Wagenlehner FM, et al. Diagnosis and management of urosepsis. Int J Urol. 2013;20(10):963-970. PMID: 23714209
- Levy MM, et al. The Surviving Sepsis Campaign Bundle: 2018 update. Intensive Care Med. 2018;44(6):925-928. PMID: 29675566