What is the most likely diagnosis and appropriate management for a 48-year-old male, status post nephrolithotomy (percutaneous nephrolithotomy (PCNL) and open nephrolithotomy), presenting 13 days post-operatively with fever, headache, left upper quadrant pain, hypotension, tachycardia, tachypnea, hyperthermia, leukocytosis, and thrombocytopenia?

Post-Nephrolithotomy Urosepsis with Septic Shock

This patient has urosepsis with septic shock requiring immediate aggressive resuscitation, broad-spectrum antibiotics, blood and urine cultures, and urgent imaging to identify and drain any obstructed or infected collection.

Most Likely Diagnosis

This clinical presentation 13 days post-bilateral nephrolithotomy is urosepsis progressing to septic shock, evidenced by:

• Fever (39.2°C) with hypotension (90/60 mmHg) meeting septic shock criteria 1
• Leukocytosis (WBC 17,000) with left shift (80% neutrophils) indicating severe infection 2, 3
• Thrombocytopenia (platelet 100,000) suggesting systemic inflammatory response or early DIC 1
• Tachycardia (HR 68 appears to be pulse, likely meant as tachycardic) and tachypnea (RR 21) indicating SIRS 4
• Post-operative day 13 places this well beyond the benign inflammatory window (48-72 hours), making infection highly likely 5, 6

The left upper quadrant pain raises concern for splenic injury (a recognized complication of left-sided PCNL) or perinephric abscess/collection 1.

Immediate Management Algorithm

Step 1: Resuscitation and Stabilization (First 1 Hour)

• Initiate aggressive IV fluid resuscitation with 30 mL/kg crystalloid bolus within first 3 hours for hypotension 1
• Obtain blood cultures (at least 2 sets) before antibiotics but do not delay antibiotic administration 5, 6
• Start broad-spectrum empiric antibiotics immediately covering gram-negative organisms and resistant pathogens:
  • Piperacillin-tazobactam 4.5g IV q6h OR
  • Carbapenem (meropenem 1g IV q8h or imipenem 500mg IV q6h) if high risk for resistant organisms 1
  • Consider adding vancomycin if MRSA risk factors present 5
• Monitor vital signs continuously with goal MAP ≥65 mmHg 1
• Consider vasopressor support (norepinephrine) if hypotension persists despite fluid resuscitation 1

Step 2: Source Identification (Within 6 Hours)

• Obtain urgent CT abdomen/pelvis with IV contrast to evaluate for:

  • Perinephric abscess or fluid collection 1
  • Residual stones or obstruction 2, 3
  • Splenic injury or hematoma (given LUQ pain) 1
  • Bowel injury (rare but possible complication) 1

• Obtain urine culture from bladder catheter specimen 1

• Check complete metabolic panel, lactate, procalcitonin to assess organ dysfunction and guide resuscitation 1

Step 3: Source Control (Urgent)

If imaging reveals obstruction or collection:

• Percutaneous nephrostomy (PCN) placement for obstructed infected system has >95% technical success and is indicated for pyonephrosis 1
• Percutaneous drainage of any perinephric abscess or significant fluid collection 1
• Interventional radiology consultation for drainage procedures 1

If splenic injury identified:

• Surgical consultation for possible splenectomy or embolization 1

Risk Factors Present in This Patient

This patient has multiple high-risk features for post-PCNL sepsis:

• Bilateral procedures increasing infection risk 2, 3
• Post-operative day 13 - beyond typical inflammatory response window 5, 6
• Possible residual stones (common cause of persistent infection) 2, 3, 7
• Thrombocytopenia associated with increased bleeding complications and sepsis [1, @16@]

The reported complication rates for PCNL include septic shock in 4% of cases overall and 10% in pyonephrosis 1. Risk factors that significantly increase sepsis risk include prolonged operative time >120 minutes, stone size >25mm, and significant bleeding requiring transfusion 3, 4.

Critical Pitfalls to Avoid

• Do not delay antibiotics waiting for culture results - septic shock requires antibiotics within 1 hour 5, 6
• Do not assume post-operative fever is benign beyond 72-96 hours - this timeframe strongly suggests infection 5, 6
• Do not miss source control - antibiotics alone are insufficient if there is an obstructed infected system or undrained collection 1
• Do not overlook splenic injury given LUQ pain and left-sided PCNL - this is a recognized complication requiring urgent intervention 1
• Do not underestimate thrombocytopenia - this may indicate DIC or severe sepsis requiring hematology consultation 1

Antibiotic Duration

• Continue IV antibiotics for 7-14 days depending on clinical response and culture results 1
• Transition to oral antibiotics once clinically stable with negative blood cultures and improving inflammatory markers 1
• Extend duration if bacteremia documented or source control delayed 1