Necrotizing fasciitis: Difference between revisions
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# | ==Background== | ||
==Risk Factors== | |||
*DM | |||
*Drug use | |||
*Obesity | |||
*Immunosuppression | |||
*Recent surgery | |||
*Traumatic wounds | |||
==Clinical Features== | |||
*Skin exam | |||
**Erythema (without sharp margins) | |||
**Exquisitely tender (pain out of proportion to exam) | |||
**Skip lesions | |||
**Hemorrhagic bullae (violaceous bullae) | |||
***May be preceded by skin anesthesia (destruction of superficial nerves) | |||
**Crepitus (in type I infections) | |||
*Swelling/edema may produce compartment syndrome | |||
*Constitutional | |||
**Fever | |||
**Tachycardia | |||
**Systemic toxicity | |||
==Work-Up== | |||
*CBC | |||
*Chem | |||
*PT/PTT/INR | |||
*CK | |||
*Lactate | |||
==Diagnosis== | |||
*Surgical exploration is the ONLY way to definitively establish the diagnosis of necrotizing infection | |||
*Imaging | |||
**Should not delay surgical exploration | |||
**CT is study of choice | |||
===HUCLA NF vs Non-NF Criteria (Wall et al)=== | |||
*Retrospective study discovered: | |||
**'''WBC count''' '''>15.4'''(x10<sup>3</sup>/mm<sup>3</sup>) OR '''Na''' '''<135'''(mmol/L) | |||
**Associated with NF and combo of both increased likelihood of NF | |||
**PPV 26%/NPV 99% | |||
*Good tool to R/O NF, not a good tool for confirming presence of NF | |||
**Helps distinguish NF from non-NF infection, when classic 'hard' signs of NF are absent | |||
===Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score (Wong et al)=== | |||
*May use to risk stratify patients p/w signs of cellulitis to determine likelihood of necrotizing fasciitis | |||
*Useful in context of a diagnosed or strongly suspected severe soft-tissue infxn | |||
*Score based on: '''CRP, WBC, Hb, Na, Cr, Glucose''' | |||
*Score > 6 has PPV of 92% and NPV of 96% for necrotizing fasciitis | |||
**Be aware LRINEC score has not been prospectively validated, index of suspicion is key | |||
#CRP (mg/L) ≥150: 4 pts | |||
#WBC count (x10<sup>3</sup>/mm<sup>3</sup>): | |||
##<15: 0 pts | |||
##15-25: 1 pt | |||
##>25: 2 pts | |||
#Hb (g/dL): | |||
##>13.5: 0 pts | |||
##11-13.5: 1 pt | |||
##<11: 2 pts | |||
#Na (mmol/L) <135: 2 pts | |||
#Cr (mg/dL) >1.6: 2 pts | |||
#glucose (mg/dL) >180: 1 pt | |||
==Treatment== | |||
*Surgical exploration and debridement | |||
**Indicated in setting of severe pain, toxicity, fever, elevated CK (w/ or w/o radiographic evidence) | |||
*Abx | |||
**Must cover Gram +/- and anaerobes (esp GAS and clostridium) | |||
**[[Piperacillin-Tazobactam]] 3.375-4.5g q6hr AND [[clindamycin]] 600-900mg q8hr AND [[vancomycin]] 1gm IV q12hr | |||
Revision as of 17:07, 6 April 2014
Background
Risk Factors
- DM
- Drug use
- Obesity
- Immunosuppression
- Recent surgery
- Traumatic wounds
Clinical Features
- Skin exam
- Erythema (without sharp margins)
- Exquisitely tender (pain out of proportion to exam)
- Skip lesions
- Hemorrhagic bullae (violaceous bullae)
- May be preceded by skin anesthesia (destruction of superficial nerves)
- Crepitus (in type I infections)
- Swelling/edema may produce compartment syndrome
- Constitutional
- Fever
- Tachycardia
- Systemic toxicity
Work-Up
- CBC
- Chem
- PT/PTT/INR
- CK
- Lactate
Diagnosis
- Surgical exploration is the ONLY way to definitively establish the diagnosis of necrotizing infection
- Imaging
- Should not delay surgical exploration
- CT is study of choice
HUCLA NF vs Non-NF Criteria (Wall et al)
- Retrospective study discovered:
- WBC count >15.4(x103/mm3) OR Na <135(mmol/L)
- Associated with NF and combo of both increased likelihood of NF
- PPV 26%/NPV 99%
- Good tool to R/O NF, not a good tool for confirming presence of NF
- Helps distinguish NF from non-NF infection, when classic 'hard' signs of NF are absent
Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score (Wong et al)
- May use to risk stratify patients p/w signs of cellulitis to determine likelihood of necrotizing fasciitis
- Useful in context of a diagnosed or strongly suspected severe soft-tissue infxn
- Score based on: CRP, WBC, Hb, Na, Cr, Glucose
- Score > 6 has PPV of 92% and NPV of 96% for necrotizing fasciitis
- Be aware LRINEC score has not been prospectively validated, index of suspicion is key
- CRP (mg/L) ≥150: 4 pts
- WBC count (x103/mm3):
- <15: 0 pts
- 15-25: 1 pt
- >25: 2 pts
- Hb (g/dL):
- >13.5: 0 pts
- 11-13.5: 1 pt
- <11: 2 pts
- Na (mmol/L) <135: 2 pts
- Cr (mg/dL) >1.6: 2 pts
- glucose (mg/dL) >180: 1 pt
Treatment
- Surgical exploration and debridement
- Indicated in setting of severe pain, toxicity, fever, elevated CK (w/ or w/o radiographic evidence)
- Abx
- Must cover Gram +/- and anaerobes (esp GAS and clostridium)
- Piperacillin-Tazobactam 3.375-4.5g q6hr AND clindamycin 600-900mg q8hr AND vancomycin 1gm IV q12hr