What is the recommended management of severe rigors in urosepsis?

Management of Severe Rigors in Urosepsis

Severe rigors in urosepsis are a symptom of the underlying septic process and do not require specific targeted therapy beyond aggressive management of the sepsis itself—focus immediately on the four pillars: early antimicrobial therapy within 1 hour, aggressive fluid resuscitation, source control, and hemodynamic support. 1

Immediate Priorities (First Hour)

1. Antimicrobial Therapy - Initiate Within 60 Minutes

Administer broad-spectrum IV antibiotics within the first hour of recognizing urosepsis, as each hour of delay increases mortality. 1, 2

First-line empirical regimens:

• Piperacillin/tazobactam 4.5 g IV every 8 hours as monotherapy 2
• Ceftriaxone 2 g IV daily PLUS gentamicin 5 mg/kg IV daily (combination therapy preferred for septic shock) 2
• Cefepime 2 g IV every 12 hours PLUS gentamicin 5 mg/kg IV daily 2

Avoid fluoroquinolones (ciprofloxacin/levofloxacin) if local resistance exceeds 10% or if the patient has used them in the past 6 months. 2

Reserve carbapenems (meropenem 1 g IV every 8 hours) for patients with known ESBL-producing organisms or multidrug-resistant pathogens. 2, 3

2. Obtain Cultures Before Antibiotics (But Don't Delay)

• Draw at least 2 sets of blood cultures (one percutaneous, one from vascular access if present) 1
• Obtain urine culture 2, 3
• Do not delay antibiotics beyond 45 minutes waiting for cultures 1

3. Aggressive Fluid Resuscitation

Administer 30 mL/kg IV crystalloid bolus within the first 3 hours for sepsis-induced hypoperfusion (hypotension or lactate ≥4 mmol/L). 1

Target these physiologic goals within the first 6 hours: 1

• Mean arterial pressure (MAP) ≥65 mmHg
• Urine output ≥0.5 mL/kg/hour
• Central venous oxygen saturation (ScvO2) ≥70% or mixed venous ≥65%
• Lactate normalization (target clearance of at least 10% every 2 hours) 1

4. Urgent Source Control - Critical for Survival

Perform imaging immediately (ultrasound or CT) to identify urinary obstruction or abscess. 1, 2, 4

Relieve any urinary tract obstruction within 12 hours—this is as critical as antibiotics for survival in urosepsis. 1, 2, 5

• Obstructed pyelonephritis from stones is the most common cause of urosepsis 5, 4
• Percutaneous nephrostomy or ureteral stent placement may be lifesaving 4

Hemodynamic Support

If hypotension persists after initial fluid bolus, start norepinephrine as first-line vasopressor to maintain MAP ≥65 mmHg. 1

Symptomatic Management of Rigors

Rigors themselves do not require specific treatment beyond managing the sepsis. The shaking chills represent the body's inflammatory response to bacteremia and will resolve as the infection is controlled. 5, 4

If rigors are severe enough to interfere with patient care or monitoring:

• Ensure adequate warming with blankets (avoid active rewarming which can worsen hemodynamics)
• Consider meperidine 25-50 mg IV (traditional agent for rigors, though not specifically studied in sepsis)
• Do NOT delay or withhold antibiotics to "see the fever curve"—this outdated practice increases mortality 1

De-escalation Strategy (48-72 Hours)

Narrow antibiotics to the most specific effective agent within 48-72 hours based on culture results. 1, 2

Discontinue combination therapy (aminoglycosides) after 48-72 hours once clinical improvement occurs. 1, 2, 3

Total treatment duration: 7-10 days for most cases with effective source control. 1, 2

Common Pitfalls to Avoid

• Do not wait for imaging results before starting antibiotics—obtain cultures, start antibiotics, then image 1, 2
• Do not use nitrofurantoin or fosfomycin for urosepsis—these agents achieve inadequate tissue concentrations in severe upper tract infections 2
• Do not delay source control—unrelieved obstruction will cause treatment failure regardless of antibiotic choice 1, 2, 4
• Do not rely on CVP alone for fluid management—use dynamic measures and the comprehensive resuscitation bundle 1
• Do not use dialysis to treat lactic acidosis—it is ineffective and potentially harmful; treat the underlying sepsis instead 6

Monitoring Parameters

• Reassess hemodynamics after each fluid bolus 1
• Measure lactate every 2-6 hours during acute resuscitation 1
• Monitor for clinical improvement: resolution of rigors, improved mental status, warming of extremities, adequate urine output 1
• If fever persists beyond 72 hours despite appropriate antibiotics, repeat imaging to identify undrained collections or persistent obstruction 2