Post Operative Fever

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Post Operative Fever

• Tad Kim, M.D.
• UF Surgery
• tad.kim_at_surgery.ufl.edu
• (c) 682-3793 (p) 413-3222

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Overview

• Definition Pathophysiology
• Differential Diagnosis
• The five W
• Modified approach to DDx
• Initial assessment and work-up
• Management
• Cases

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Definition Pathophysiology

• Fever is temp 38 degrees Celsius
• Manifestation of cytokine release/response
• By monocyte, macrophages, endothelial cells
• IL-1, IL-6, TNF-alpha, IFN-gamma
• Act on the hypothalamic endothelium
• Stimulate produx of PGE2 cAMP release
• cAMP acts as neurotransmitter raises the
  set-point gt heat conservation production

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Differential Diagnosis

• The Five W timing of each
• Wind (POD1) atelectasis, pneumonia
• Water (POD3) UTI, anastomotic leak
• Wound (POD5) wound infex, abscess
• Walking (POD7) DVT / PE
• Wonder-drug or What did we do?
• Many drugs cause fever, ?blood transfusions,
  central lines we put in (line sepsis)

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Differential Diagnosis

• Five Ws are a guide for the most common
• But also learn to think worst-case scenario
• What can kill this patient if I miss the dx?
• In general, early fever is not infectious with
  one critical exception Necrotizing fasciitis or
  soft tissue infection
• Most early post-op fever resolves w/o tx
• Simply a reaction/response to the surgery
• Fever occuring later more likely infectious

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DDx Modified Approach

• Immediate fever onset in OR or hrs after
• Killers
• necrotizing infection (can kill rapidly)
• Clostridium perfringens, Group A ß-hemo strep
• Tx ABC, Resusc, Pen G, surgical debridement
• malignant hyperthermia
• Tx ABC, Resusc, rapid cooling, IV dantrolene
• Other Allergic rxn (to abx) or transfusion
• Look for hypotension, rash
• Tx Stop the offending agent

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DDx Modified Approach

• Acute fever within first week after surgery
• In addition to five Ws, think of these
• Killers
• necrotizing infection (within 48hrs)
• anastomotic leak (classically POD 3 to 5)
• new abd pain, distension, peritoneal signs
• fever, tachycardia, hypotension
• pulmonary embolism or MI (can p/w fever)
• Other VAP, aspiration, nosocomial infex, EtOH
  withdrawal (day 3), acute gout

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DDx Modified Approach

• Subacute/delayed fever after 5days post-op,
  infectious etiology is more likely
• 1 Wound infection (40)
• 2 UTI (29) especially if indwelling Foley
• 3 Pneumonia (12) if on vent or COPD
• Also think of C.dif colitis, line sepsis
  bacteremia, intra-abdominal abscess
• Rarer sinusitis, meningitis, peri-rectal
  abscess, acalculous cholecystitis, parotitis
• Weeks out endocarditis, infected prostheses

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Initial Assessment

• If called for fever, get to the bedside, get the
  nurse/flowsheet and ABC with vitals
• Obtain a history or use the AMPLE format
• Type of surgery, meds or blood given, other
  symptoms (rash, cough, dyspnea, chest pain,
  dysuria, leg swelling, painful IV site, abd pain)
• Physical
• 1 check the wound or surgical site
• 2 lung sounds, heart/abd/extremity exam
• 3 check IV sites, central line, Foley, tubes

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Work-Up

• Labs if concerned about infection
• CBC w diff, Sputum Cx, UCx, Blood Cx x2
• Lumbar puncture (if AMS, neck pain, fever)
• C.dif toxin assay
• STAT gram stain if suspect necrotizing infex
• Imaging
• CXR (for pneumonia)
• Lower extremity venous duplex (for DVT)
• CT scan (for abscess, leak or PE protocol)
• RUQ ultrasound (if suspect cholecystitis)

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Management

• Remove/replace sources of infection
• Foley catheter, central lines, or peripheral IVs
• Open, debride, and drain infected wounds
• Antibiotics not indicated for wound infex unless
  associated cellulitis
• Tylenol 10mg/kg (ped) or 650mg po x1
• If suspect pneumonia, bacteremia, UTI, sepsis
  start broad spectrum antibiotics

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Case 1

• 58yo man 5hrs after bilateral total knee
  arthroplasty. Temp of 38.7 C
• Only c/o knee pain controlled w meds
• On no antibiotics, taking home meds
• VS Pulse 90, BP 130/70, O2 sat 99
• Mild serosanguinous drainage from knees
• No Foley or central lines, WBC 7 (normal)
• What do you do?

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Case 1

• What do you do?
• A. Urine culture
• B. Blood, urine cultures CXR
• C. Blood, urine cultures vancomycin
• D. Observation only

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Case 2

• 65yo obese, diabetic female 5hrs s/p open choly
  for gangrenous cholecystitis. Called with T 40.0
  C, tachycardia, abd pain
• Sx Altered mentation, abd pain
• VS P 140, BP 88/50, O2 Sat 94
• PE Wound is blistered, crepitus, sub-Q gas
  dirty, dishwater drainage
• Gram stain of fluid shows gram pos rods

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Case 2

• What is the diagnosis?
• A. Cellulitis
• B. Diffuse peritonitis
• C. Necrotizing fasciitis
• D. Uncomplicated post operative fever
• What is the organism on gram stain?
• A. Group A strep
• B. MRSA
• C. Clostridium perfringens
• D. Enterococcus

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Case 2 Lessons

• Necrotizing fasciitis
• Type I Polymicrobial with aerobes/anaerobes usu.
  occurs after surgery, in DM or PVOD
• Type II Monomicrobial 2ndary to Group A strep,
  Strep pyogenes
• MRSA is becoming more common for Type II
• ABC, ?intubate, 2 large IV, resuscitate
• Early Pen G Broad-spectrum antibiotics
• Early surgical debridement
• Mortality is 100 with antibiotics alone

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Case 3

• 61yo F w rheumatoid arthritis on methotrexate
  undergoes left total hip. Has Foley catheter
  postoperatively. Fever of 38.1 C on POD1, Foley
  is removed. Then has fever of 38.5 C on POD4.
• She has been ambulating, using incentive
  spirometry, O2 Sats and vitals are normal
• Wound is clean

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Case 3

• What is the most likely diagnosis?
• A. Deep venous thrombosis
• B. Urinary tract infection
• C. Superficial wound infection
• D. Prosthesis infection

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Take Home Points

• Know the five Ws as a rough guide for most
  common causes timing
• Learn to think of what can kill the patient
• Also think what did we do to cause this?
• Targeted HP / labs / imaging to rule out the
  killers, then confirm most likely cause
• Should have a working diagnosis before labs
• Know the dx treatment of nec fasciitis