What is the management for a patient with rigors on day 14 post Transforaminal Lumbar Interbody Fusion (TLIF)?

Management of Rigors on Day 14 Post-TLIF

Rigors on day 14 post-TLIF should be treated as a postoperative infection until proven otherwise, requiring immediate infectious workup with blood cultures, wound evaluation, inflammatory markers (CBC with differential, ESR, CRP), and empiric broad-spectrum antibiotics pending culture results.

Immediate Assessment and Workup

Clinical Evaluation

• Examine the surgical wound for signs of infection including erythema, warmth, drainage, dehiscence, or fluctuance 1
• Assess for deep infection indicators such as persistent fever >38.5°C, severe back pain worse than expected postoperatively, or neurological changes 1
• Document vital signs including temperature pattern, as rigors significantly increase the likelihood of bacterial infection requiring immediate antibiotic therapy 1

Laboratory Investigation

• Obtain complete blood count with differential, specifically evaluating absolute band count >1500/mm³, which significantly increases the relative risk for bacterial infection by a factor of 1.35 when combined with rigors 1
• Draw blood cultures before initiating antibiotics, as rigors are associated with significantly greater yield of positive blood cultures (P < 0.04) 1
• Check inflammatory markers including ESR and CRP to establish baseline and monitor treatment response 1

Imaging Studies

• Order MRI with gadolinium contrast of the lumbar spine to evaluate for epidural abscess, discitis, or osteomyelitis if infection is suspected 2
• Consider CT if MRI contraindicated due to hardware, though MRI is superior for soft tissue evaluation 2

Empiric Antibiotic Management

Initial Therapy

• Start broad-spectrum IV antibiotics immediately after obtaining cultures, covering both gram-positive organisms (including MRSA) and gram-negative bacteria 1
• Typical regimen: Vancomycin 15-20 mg/kg IV every 8-12 hours PLUS either ceftriaxone 2g IV daily or cefepime 2g IV every 8 hours 1
• Adjust based on culture results and local antibiogram patterns once available 1

Differential Diagnosis Considerations

Non-Infectious Causes (Less Likely at Day 14)

• Drug reaction: Review all medications started perioperatively, though this typically presents earlier 3
• Transfusion reaction: If patient received blood products, though timing makes this less likely 4
• Deep vein thrombosis or pulmonary embolism: Consider if rigors accompanied by respiratory symptoms or unilateral leg swelling 4

Infection-Related Causes (Most Likely)

• Surgical site infection (superficial or deep): Most common cause at this timeframe post-spinal fusion 1, 2
• Urinary tract infection: Common postoperative complication, especially if catheterized 1
• Pneumonia: Particularly in patients with limited mobility post-surgery 1
• Bacteremia from any source: Rigors in hospitalized patients significantly increase likelihood of bacterial infection to 66% versus 50% without rigors (P < 0.005) 1

Surgical Consultation

Indications for Urgent Surgical Evaluation

• Any signs of wound infection require immediate spine surgery consultation for possible irrigation and debridement 2
• Neurological deterioration suggesting epidural abscess requires emergent surgical decompression 2
• Imaging evidence of hardware infection may necessitate hardware removal and staged reconstruction 2

Symptomatic Management

Fever and Rigor Control

• Acetaminophen 650 mg PO every 4 hours scheduled for fever >38.5°C 4
• Meperidine 25-50 mg IV every 4 hours PRN for rigors, may repeat within 30 minutes as needed 4
• Hydromorphone 0.5 mg IV every 15 minutes as alternative for rigors, may repeat up to 3 total doses 4
• Avoid NSAIDs if renal function compromised or platelet count <50,000/mm³ 4

Critical Pitfalls to Avoid

• Do not delay antibiotic initiation while awaiting culture results in a patient with rigors post-spinal surgery, as this represents a surgical emergency if deep infection present 1
• Do not attribute rigors to "normal postoperative course" at day 14—this timing is beyond typical inflammatory response and warrants full infectious workup 1, 2
• Do not rely solely on wound appearance—deep infections can present with minimal external signs while causing systemic symptoms 1
• Do not discharge patient until infection ruled out or adequately treated, as postoperative spinal infections carry significant morbidity risk 2