Clinical Reconstruction

• BP ~180 mmHg systolic (? hypertensive + sepsis)
• SpO2 91% on room air (hypoxemic)
• TLC (WBC) ~6810/mm³ (or possibly higher - "CBR 681" likely = 6810, not leukopenic but context matters)
• Creatinine 1.3 mg/dL (mildly elevated)
• "HDL-C 2" likely = Hb 9-10 g/dL (anaemia) or TLC 2000 with some transcription noise
• "400" likely = ESR, CRP, or platelet count - context needed but likely CRP or ESR elevated

Working Diagnosis: Urosepsis with Sepsis-Associated Pulmonary Complications

The Unifying Story

1. Residual or recurrent obstruction after stent removal (stone may not have passed completely)
2. Infected hydronephrosis / early pyonephrosis - stagnant urine behind an obstructed ureter is a perfect culture medium
3. Urosepsis - bacteremia seeding from the urinary source

• Systemic inflammatory response from urosepsis causes capillary leak
• Results in bilateral pleural effusions (transudative/exudative) and pulmonary infiltrates
• Classic presentation of early ARDS/sepsis-associated pulmonary injury

• Gram-negative bacteremia (E. coli, Klebsiella, Proteus - the most common urosepsis organisms) can cause hematogenous seeding of the lungs
• Murray & Nadel's Respiratory Medicine notes: "if pulmonary infarction results from a septic embolism, pleuritic chest pain and hemoptysis are often noted" - classic presentation with peripheral infiltrates
• Right upper zone infiltrates could represent a septic embolic focus
• A case report (PMID 34426427) describes septic pulmonary emboli as a rare but documented complication of Proteus mirabilis UTI

• Post-instrumentation state, fever, reduced oral intake, bed rest
• Goldman-Cecil Medicine notes bilateral infiltrates, pleural effusion, and bacteremia as hallmarks of gram-negative healthcare-associated pneumonia

Problem-Oriented Approach

Step 1 - Establish Sepsis Severity

• SpO2 91% → respiratory rate likely elevated (RR criterion met)
• BP 180 (high, not low - but may mask underlying vasodilatory sepsis; watch for deterioration)
• Creatinine 1.3 → early organ dysfunction (AKI)

Step 2 - Identify the Source

Immediate Management

A. Resuscitation (First Hour - "Sepsis Bundle")

1. IV access x2 + aggressive IV fluid resuscitation (30 mL/kg crystalloid bolus if BP drops or lactate >2)
2. Blood cultures x2 sets BEFORE antibiotics
3. Urine culture + urinalysis + urine microscopy
4. Measure serum lactate - if >2 mmol/L = septic shock risk
5. Supplemental O2 - target SpO2 >94%; consider non-rebreather mask now; ICU referral if worsening

B. Empiric Broad-Spectrum Antibiotics (within 1 hour)

• Piperacillin-tazobactam 4.5g IV q8h (covers gram-negatives including Pseudomonas, covers anaerobes) OR
• Meropenem 1g IV q8h if: prior instrumentation + hospital-acquired concern + worsening AKI (carbapenem provides broadest coverage for urologic sepsis post-procedure)
• Add Vancomycin if MRSA/gram-positive concern (right upper zone cavitating infiltrate, prior healthcare contact)

C. Urologic Intervention (CRITICAL - Source Control)

• Urgent urologic review is mandatory
• Repeat CT KUB / CT urogram to assess:
  • Did the stone pass after DJ stent removal?
  • Is there residual obstruction, hydronephrosis, or abscess?
  • Any perinephric collection?
• If obstruction is present: Emergency re-DJ stenting or nephrostomy drainage - infected obstructed kidney (pyonephrosis) is a urologic emergency; antibiotics alone are insufficient
• Symptom to Diagnosis (4th Ed.) emphasizes that urosepsis requires hospitalization, often ICU, with IV antibiotics + source control

D. Pulmonary Workup

• CT chest (or HRCT) to characterize infiltrates:
  • Septic emboli: peripheral, nodular, may cavitate, bilateral peripheral nodules
  • ARDS/sepsis-lung: bilateral alveolar/ground-glass, central distribution
  • Pneumonia: lobar/segmental consolidation
  • TB must be excluded: right upper zone infiltrate in a febrile patient - send sputum AFB x3, Mantoux/IGRA, check HIV status
• Echocardiogram if septic emboli are suspected - rule out endocarditis as embolic source (though primary source here is urinary, secondary endocarditis is possible in prolonged bacteremia)
• Pleural tap if effusion is large - send for LDH, protein (exudate vs. transudate), pH, glucose, gram stain, culture

E. Investigations to Send Now

Differential Summary (in order of likelihood)

1. Urosepsis secondary to residual/recurrent ureteric obstruction / pyonephrosis - primary diagnosis
2. Sepsis-associated pulmonary injury / early ARDS - explains bilateral effusions + hypoxemia
3. Septic pulmonary emboli from gram-negative bacteremia - explains focal right upper zone infiltrate
4. Healthcare-associated pneumonia - post-instrumentation, reduced mobility
5. Pulmonary TB reactivation - must exclude in right upper zone disease with systemic illness, especially in South Asian setting
6. Infective endocarditis with septic emboli - less likely but requires exclusion if bacteremia confirmed

Red Flags Requiring Immediate ICU Escalation

• SpO2 declining below 88% despite supplemental O2
• Systolic BP drops below 100 (septic shock)
• Lactate >4 mmol/L
• Oliguria or worsening AKI
• Altered sensorium

• Symptom to Diagnosis, 4th Ed., Chapter on Urosepsis
• Goldman-Cecil Medicine, Healthcare-Associated Pneumonia section
• Murray & Nadel's Respiratory Medicine, Hematogenous S. aureus / Septic Emboli section
• Sepsis-3 criteria per Harrison's Principles of Internal Medicine, 22nd Ed.