Surgical Site Infection: New Solutions to a Continuing Problem R. Lawrence Reed, II, MD, FACS, FCCM Professor of Surgery Loyola University Medical Center

Surgical Site Infection:New Solutions to a Continuing Problem

R. Lawrence Reed, II, MD, FACS, FCCMProfessor of Surgery

Loyola University Medical CenterDirector, SICU, Hines VA Medical Center

Maywood, IL

Surgical Site Infections (SSI)

• Third most common nosocomial infection (14%–16%)

• Most common nosocomial infection among surgical patients (38%)– 2/3 incisional– 1/3 organs or spaces accessed during surgery

• 7.3 additional postoperative days at cost of $3,152 in extra charges

Mangram AJ et al. Infect Control Hosp Epidemiol. 1999;20:250-278.

Colonization vs Contamination – Definitions

• Colonization– Bacteria present in a wound with no signs or symptoms

of systemic inflammation– Usually less than 105 cfu/mL

• Contamination– Transient exposure of a wound to bacteria– Varying concentrations of bacteria possible– Time of exposure suggested to be < 6 hours– SSI prophylaxis best strategy

SSI – Definitions

• Infection– Systemic and local signs of inflammation– Bacterial counts ≥ 105 cfu/mL– Purulent versus nonpurulent– LOS effect– Economic effect

• Surgical wound infection is SSI

LOS=length of stay.

Superficial Incisional SSI

Infection occurs within 30 days after the operation and involves only skin or subcutaneous tissue of the incision


Subcutaneous Subcutaneous tissuetissue

SkinSkinSuperficial incisional SSI

Deep Incisional SSIInfection occurs within 30 days after the operation if no implant is left in place or within 1 year if implant is in place and the infection appears to be related to the operation and the infection involves the deep soft tissue (e.g., fascia and muscle layers)

Deep soft tissue Deep soft tissue (fascia & muscle)(fascia & muscle)

Deep incisional SSI

Superficial incisional SSI


Organ/Space SSI

Infection occurs within 30 days after the operation if no implant is left in place or within 1 year if implant is in place and the infection appears to be related to the operation and the infection involves any part of the anatomy, other than the incision, which was opened or manipulated during the operation

Deep incisional SSI

Superficial incisional SSI

Organ/space SSIOrgan/spaceOrgan/space


SSI – Risk FactorsOperation Factors

• Duration of surgical scrub• Maintain body temp• Skin antisepsis• Preoperative shaving• Duration of operation• Antimicrobial prophylaxis• Operating room ventilation• Inadequate sterilization of

instruments


• Foreign material at surgical site

• Surgical drains• Surgical technique

– Poor hemostasis– Failure to obliterate

dead space – Tissue trauma

SSI – Risk FactorsPatient Characteristics

• Age• Diabetes

– HbA1C and SSI– Glucose > 200 mg/dL

postoperative period (<48 hours)

• Nicotine use: delays primary wound healing

• Steroid use: controversial• Malnutrition: no

epidemiological association• Obesity: 20% over ideal body

weight


• Prolonged preoperative stay: surrogate of the severity of illness and comorbid conditions

• Preoperative nares colonization with Staphylococcus aureus: significant association

• Perioperative transfusion: controversial

• Coexistent infections at a remote body site

• Altered immune response

Bacterial dose Virulence

Impairedhost resistance

Risk of Infection



Risk of Infection



Virulence


Risk of InfectionRisk of Surgical Infection

Bacterial dose

SSI – Wound Classification

• Class 1 = Clean

• Class 2 = Clean contaminated

• Class 3 = Contaminated

• Class 4 = Dirty infected


Prophylactic antibiotics indicated

Therapeutic antibiotics

SSI – Risk Stratification NNIS Project

3 independent variables associated with SSI risk

– Contaminated or dirty/infected woundclassification

– ASA > 2– Length of operation > 75th percentile of the

specific operation being performed

NNIS=National Nosocomial Infections Surveillance.

NNIS. CDC. Am J Infect Control. 2001;29:404-421.

SSI – Wound Class vs NNIS Class

Wound Class All NNIS 0 NNIS 1 NNIS 2 NNIS 3

Clean 2.1% 1.0% 2.3% 5.4% N/A

Clean contaminated 3.3% 2.1% 4.0% 9.5% N/A

Contaminated 6.4% N/A 3.4% 6.8% 13.2%

Dirty infected 7.1% N/A 3.1% 8.1% 12.8%

All 2.8% 1.5% 2.9% 6.8% 13.0%


Campaign to PreventAntimicrobial Resistance

• Centers for Disease Control and Prevention

• National Center for Infectious Diseases

• Division of Healthcare Quality Promotion

Link to: Campaign to Prevent Antimicrobial Resistance OnlineLink to: Federal Action Plan to Combat Antimicrobial Resistance

Clinicians hold the solution!

http://www.cdc.gov/drugresistance/healthcare

http://www.cdc.gov/drugresistance/actionplan/index.htm

12 Steps to Prevent Antimicrobial Resistance AmongSurgical Patients

• Step 1 – Prevent SSIs – Monitor and maintain normal

glycemia

– Maintain normothermia

– Perform proper skin preparation using appropriate antiseptic agent and, when necessary, hair removal techniques

– Think outside the wound to stop surgical site infections

CDC. Available at http://www.cdc.gov/drugresistance/healthcare/surgery/12steps_surgery.htm. Accessed July 16, 2004.

Opportunity to Prevent SSI

• An estimated 40%–60% of SSIs are preventable

• Overuse, underuse, improper timing, and misuse of antibiotics occurs in 25%–50% of operations


Principles of Antibiotic Prophylaxis


Preop administration, serum levels adequate throughout procedure with a drug active

against expected microorganisms.

High Serum Levels1. Preop timing2. IV route3. Highest dose

of drug

During Procedure1. Long half-life2. Long procedure–

redose3. Large blood loss–

redose

Duration1. None after wound

closed2. 24 hours maximum

Surgical Site Infection (SSI)


Surgical Infection Prevention ProjectMedicare Quality Improvement Community

Clinical Infectious Diseases 2004 June; 38:1706–15

http://www.medqic.org/portal/homepage.jsp

National Data Collection

• State-level baseline description from random sample of 788 cases per state

• Data collected from records by two professional clinical data abstraction centers

• Abstraction tool for hospitals is available….Is JCAHO compatible

Surgical Infection PreventionPreliminary Results

34,133 (87.3)Cases eligible for analysis

205 (0.52)

1,817 (4.7)

2 (0.01)

1,461 (3.74)

1,432 (3.66)

36 (0.09)

General Exclusions

Surgery of interest not performed

Infection present pre-operatively

Missing antibiotic dates and times

Patient on antibiotics prior to admission

Patient on antibiotics for more than 24 hours pre-op

Other

39,086 (100)Number of cases reviewed

N (%)

26.2

10

22.6

6.2 6.32.2 2.7

9.3

14.5

40.7

50.7

73.3

79.5

85.888

90.7

0

20

40

60

80

100

12 o

r les

s

>12-

24

>24-

36

>36-

48

>48-

60

>60-

72

>72-

84

>84-

96>

96

Hours After Surgery End Time

Pe

rce

nt

0

20

40

60

80

100

Cu

mu

lati

ve

Pe

rce

nt

Discontinuation of Antibiotics

Patients were excluded from the denominator of this performance measure if there was any documentation of an infection during surgery or in the first 48 hours after surgery.

Most Common Pathogens Associated With Nosocomial Infections

(NNIS 1989–1998) Medical & Surgical Combined

Pathogen All Sites BSI Pneumonia SSIn=235,758 n=50,091 n=64,056 n=22,043

Coag-neg Staph 14.3 39.3 2.5 13.5S aureus 11.4 10.7 16.8 12.6Enterococci spp. 8.1 10.3 1.9 14.5P aeruginosa 9.9 3.0 16.1 9.2Enterobacter spp. 7.3 4.2 10.7 8.8E coli 7.0 2.9 4.4 7.1C albicans 6.6 4.9 4.0 4.8K pneumoniae 4.7 2.9 6.5 3.5Others 30.7 21.8 37.1 26.0

Relative Percentage by Site of Infection

BSI=bloodstream infection; SSI=surgical site infection.Fridkin SK et al. Clin Chest Med. 1999;20:303-316.

Predominance of S aureus in Skin and Skin Structure Infections (SSSIs)

SENTRY – US and Canada 2000

Rennie RP et al. Diagn Microbiol Infect Dis. 2003;45:287-293.

N=1,404 isolates

S aureus 45.9%

10.8% P aeruginosa

Enterococci 8.2%

E coli 7.0%

Enterobacter 5.8%

Other 17.3% MSSA 30.9%

MRSA ~15%

Klebsiella 5.1%

0

10

20

30

40

50

60

Re

sist

an

t is

ola

tes

(%)

CDC. MMWR. 1997;46:624-628, 635. (1975 data); Lowy FD. N Engl J Med. 1998;339:520-532. (1987-1997 data); CDC. NNIS System Report, January–November 1998. (1998 data); CDC. NNIS System Report, January 1990–May 1999, issued June 1999. Am J Infect Control. 1999;27:520-532. (1999 data); CDC. NNIS System Report, January 1992–June 2001. Am J Infect Control. 2001;29:404-421. (2000 data); NNIS. CDC. Am J Infect Control. 2003;31:481-498.

Progression of Methicillin Resistant S aureus – United States 13%

Impact of MRSA on SSI

• N=479 patients• MRSA greater 90-d

mortality vs MSSA (adjusted odds ratio, 3.4; 95% CI: 1.5–7.2)

• MRSA longer LOS after infection (median additional days=5; P<0.001)

• MRSA associated with greater hospital charges (1.19-fold increase in hospital charges, P=0.03)

Engemann JJ et al. Clin Infect Dis. 2003;36:592-598.

29,455

52,971

92,363

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

Control

MSSA

MRSA

Median Hospital Charges

Vascular SSI

• Retrospective review (1993–2000)– Leicester Royal Infirmary, United Kingdom

– 172 patients MRSA-positive (4.4% of total)

– 75 infected, 97 colonized

• Proportion of wound/graft infections caused by MRSA has increased– 4% in 1994, increased to 63% in 2000

• All patients with aortic graft infection died

• All patients with infected prosthetic infrainguinal bypass required amputations

Nasim A et al. Eur J Vasc Endovasc Surg. 2001;22:211-214.

MRSA in Orthopedic SSI

• Prospective study, London, United Kingdom• 12-month study, January through December 2000• Total of 1,879 patients admitted, 121 screened• 1.6% of total with MRSA infection/colonization• Higher risk for MRSA infection

– Hip surgery– Emergency surgery for femoral neck fracture– Presence of wound

• MRSA infection – increased hospital LOS (88 vs 11 days)• 41% of positive patients still carried MRSA on discharge

Tai CC et al. Int Orthop. 2004;28:32-35.

MRSA in Cardiac Surgery

• 3,443 CABG patients, all received antimicrobial prophylaxis

• June 1997 through December 2000

• Sternal SSI developed in 122 (3.5%)– 71 (58.2%) were superficial SSI

– 51 (41.8%) were deep SSI

• Gram-positive cocci were most frequently recovered (81%)

• S aureus was the most frequently isolated pathogen (49%)

• S aureus bacteremia occurred in 18% and was significantly associated with deep SSI (P=0.002)

CABG=coronary artery bypass grafting.Sharma M et al. Infect Control Hosp Epidemiol. 2004;25:468-471.

Impact of MRSA in Cardiac Surgery

• Retrospective review (41 patients)– Poststernotomy S aureus

mediastinitis– MRSA: 15 patients– MSSA: 26 patients

• Logistic regression analysis: MRSA was the only independent risk factor for increased mortality, P=0.04

Mekontso-Dessap A et al. Clin Infect Dis. 2001;32:877-883.

0

10

20

30

40

50

60

70

80

90

MRSA MSSA

1 month

1 year

3 years

Survival Rates

Nasal Mupirocin and SSI

• 4,030 patients enrolled, 3,864 ITT patients

• PRDBPCT, intranasal mupirocin

• 891 patients (23.1%) had S aureus in anterior nares– 444 mupirocin,– 447 placebo

• S aureus SSI:– 2.3% mupirocin– 2.4% placebo

ITT=intent-to-treat; PRDBPCT=prospective, randomized, double-blind placebo-controlled trial.Perl TM et al. N Engl J Med. 2002;346:1871-1877.

Per

cent

of p

atie

nts

with

S a

ureu

s (

%)

4

7.7

Mupirocin Placebo

P=0.02

All postoperative S aureus Infections

Surgical Wound ManagementSSI Prophylaxis in MRSA-Colonized Patient

• Must use same principles• Drug choice difference• MRSA drugs

– Vancomycin

– Quinupristin/dalfopristin*

– Linezolid

– Daptomycin

*Not FDA approved for MRSA.

Vancomycin

• Bactericidal glycopeptide– Discovered in 1956– Produced by Streptococcus

orientalis, an actinomycete isolated from soil samples from Indonesia & India

• Introduced clinically in 1958• Quickly overshadowed by

less toxic anti-staphylococcal penicillins and cephalosporins

• Re-emergence as an important antibiotic in 1980s & 1990s

Historical Yearly Usage of Vancomycin

Kirst HA et al. Antimicrob Agents Chemother. 1998;42:1303-1304; NNIS. Am J Infect Control. 2001;29:404-421.

2001: 1.8 million courses of vancomycin annually in U.S.30 million doses of vancomycin estimated

12 Steps to Prevent Antimicrobial Resistance AmongSurgical Patients

• Step 9. Know when to say “no” to vanco– Vanco should be used to treat

known infections, not for routine prophylaxis

– Treat staphylococcal infection, not contaminants or colonization

– Consider other antimicrobials in treating MRSA

CDC. Available at http://www.cdc.gov/drugresistance/healthcare/surgery/12steps_surgery.htm. Accessed July 16, 2004.

Vancomycin Tissue Penetration

• 33 open-heart surgery patients, mean vancomycin concentrations after 15 mg/kg IV dose– Below the mean

MICs for many strains of staphylococci

MIC=minimum inhibitory concentration.Daschner FD et al. J Antimicrob Chemother. 1987;19:359-362.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Cardiac Valve Myocardium Fat

Tissue

Lev

el (

mg

/L) Tissue Level (mg/L)

MIC (mg/L)

Bone5:7%–13%

Vancomycin Penetration

Sternal Bone1:57%

Heart Valve4:12%

CNS:<10%

Fat4: 14%

Muscle4:9%

Epitheliallining fluid3:

18%

Lung tissue2:17%–24%

1. Massias L et al. Antimicrob Agents Chemother. 1992;36:2539-2541; 2. Cruciani M et al. J Antimicrob Chemother. 1996;38:865-869. 3. Lamer C et al. Antimicrob Agents Chemother. 1993;37:281-286; 4. Daschner FD et al. J Antimicrob Chemother. 1987;19:359-362; 5. Graziani AL et al. Antimicrob Agents Chemother. 1988;32:1320-1322.

Quinupristin/Dalfopristin (Synercid®)

• Streptogramin class related to macrolide-lincosamides– Quinupristin is a Group B streptogramin

– Dalfopristin is a Group A streptogramin

• Activity against:– MSSA – potently bactericidal

– Streptococcus pneumoniae (including PRSP) – potently bactericidal

– MRSA – moderately active

– E faecium – moderately active against most E faecium strains

– NO activity against E faecalis

PRSP=penicillin-resistant Streptococcus pneumoniae.Synercid® IV (quinupristin/dalfopristin for injection) [package insert]. Bristol, Tenn: Monarch Pharmaceuticals, Inc; 2002.

Quinupristin/Dalfopristin (Synercid®)

• Central line access used to decrease incidence of infusion-related venous irritation

• 3%–30% incidence of severe myalgias and arthralgias

• Resistance has already been reported • Bacteriostatic• Does not have indication for pneumonia

– Did not perform as well as vancomycin

Synercid® IV (quinupristin/dalfopristin for injection) [package insert]. Bristol, Tenn: Monarch Pharmaceuticals, Inc; 2002.

Daptomycin (Cubicin™)

• Lipopeptide natural product • Activity in Gram-positive organisms• Distinct mechanism of action• Rapidly bactericidal in vitro and in vivo• No mechanisms of resistance identified • No cross-resistance with other antibiotics • Safety profile similar to comparators• Once-daily IV dosing

Cubicin™ (daptomycin for injection) [prescribing information]. Lexington, MA: Cubist Pharmaceuticals; September 2003.

Linezolid (ZYVOX®)

• An oxazolidinone: a novel antimicrobial class

• 100% oral bioavailability

• Equivalent dosing oral/IV

• No dose adjustment in renal failure

• Bacteriostatic

• No cross-resistance with other antibiotics

• Reversible thrombocytopenia with prolonged use

• Binds selectively to the 50S ribosomal subunit– Inhibits the formation of a functional initiation complex

ZYVOX® (linezolid injection, tablets, and oral suspension) [package insert]. Kalamazoo, Mich: Pharmacia & Upjohn, a Pfizer Company; revised June 2004.

Average Steady-State Plasma Linezolid Concentrations After Oral Administration

of 400 or 600 mg Twice Daily

0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20

Lin

ezol

id c

once

ntra

tion

(μg

/mL

)

Time After Last Dose (hours)

600 mg BID

400 mg BID

MIC-90 Staph

MIC-90 Entero

MIC-90 Strep

Linezolid Research Update. Denver, Colo: Infectious Diseases Society of America; November 13, 1998.

Linezolid Penetration

Saliva2:120%

CNS1:70%*

Bone3:40%–60%

Sweat2:55%

Skin Blister Fluid5:100%

Epitheliallining fluid4:

450%

Alveolar cells4:15%

1. Cottagnound et al. J Antimicrob Chemother. 2000;46:981-985; 2. ZYVOX® (linezolid injection, tablets, and oral suspension) [package insert]. Kalamazoo, Mich: Pharmacia & Upjohn, a Pfizer Company; revised 2003; 3. Lovering AM et al. J Antimicrob Chemother. 2002, 50:73-77; 4. Conte JE et al. Antimicrob Agents Chemother. 2002;46:1475-1480; 5. Gee T. Antimicrob Agents Chemother. 2001;45:1843-1846.

1. Graziani AL et al. Antimicrob Agents Chemother. 1988;32:1320-1322; 2. Matzke et al. Clin Pharmacokinet. 1986;11:257-282; 3. Albanese J et al. Antimicrob Agents Chemother. 2000;44:1356-1358; 4. Georges H et al. Eur J Clin Microbiol Infect Dis. 1997;16:385-388; 5. Lamer C et al. Antimicrob Agents Chemother. 1993;37:281-286; 6. Daschner FD et al. J Antimicrob Chemother. 1987;20:776-782; 7. Blevins RD et al. Antimicrob Agents Chemother. 1984;25:603-606; 8. Lovering AM et al. J Antimicrob Chemother. 2002;50:73-77; 9. Conte JE et al. Antimicrob Agents Chemother. 2002;46:1475-1480; 10. Gee T et al. Antimicrob Agents Chemother. 2001;45:1843-1846; 11. Gendjar SR et al. 2001 ASN/ISN World Congress of Nephrology; 2001; San Francisco, Calif. Abstract 550865.

Comparison of Tissue Concentrations (% Tissue/Serum)

Tissue Vancomycin Linezolid

Bone 7%–13%1 60%8

Cerebral Spinal Fluid 0%–18%2,3 70%9

Epithelial Lining Fluid (Lung) 11%–17%4,5 450%9

Inflammatory Blister Fluid ---- 104%10

Muscle ~30%6 94%8

Peritoneal dialysis fluid ~20%7 61%11

Complicated Skin and Soft Tissue Infection (cSSTI) Treatment

• Staph most common cause• Staph resistance continues to increase

– 57.1% in 2002

• Treatment for MRSA cSSTI prior to 2000– Vancomycin– Quinupristin/dalfopristin*

• New alternatives for treatment of MRSA cSSTI– Linezolid– Daptomycin



Quinupristin/Dalfopristin† (Q/D) Efficacy• Design: 2 randomized, open-label, controlled clinical trials in cSSSI

– Study 1: Q/D (7.5 mg/kg q12h IV) vs oxacillin (2 g q6h IV)*

– Study 2: Q/D (7.5 mg/kg q12h IV) vs cefazolin (1 g q8h IV)*

Q/D (n=450)

Comparator (n=443)

Study 1 (US) 49.5% 51.9%

Study 2 (International) 66.4% 64.2%

Postoperative infections‡ 14/38 (36.8%) 24/42 (57.1%)

Traumatic wound infections‡ 33/55 (60.0%) 33/55 (60.0%)

*Vancomycin 1 g q12h IV could be substituted if the pathogen was suspected or confirmed methicillin-resistant Staphylococcus or the patient was allergic to penicillin, cephalosporins, or carbapenems. †Patients cured or improved. ‡Results are combined from the 2 clinical trials. Statistical conclusions could not be reached due to the small number of patients in the subsets.

Efficacy in the Clinically Evaluable Population†

Synercid® IV (quinupristin/dalfopristin for injection) [package insert]. Bristol, Tenn: Monarch Pharmaceuticals, Inc; 2002.

†Not FDA approved for MRSA.

Quinupristin/Dalfopristin† (Q/D) Efficacy• Design: 2 randomized, open-label, controlled clinical trials in cSSSI

Summary of Clinical and Microbiologic Results*Q/D

(n=450)

Comparator

(n=443)

Clinical efficacy† 68.2% 70.7%

Microbiologic eradication‡ 66.6% 77.7%

MSSA 64.3% 76.6%

MRSA 77.8% 50.0%

Gram-positive cocci only 56.3% 69.7%

*Results are combined from the 2 clinical trials. ††Patients cured or improved in the clinically evaluable population. ‡Overall and by-pathogen bacteriologic eradication rates in the microbiologically evaluable population.cSSSIs=complicated skin and skin structure infections.

Nichols RL et al. J Antimicrob Chemother. 1999;44:263-273.

†Not FDA approved for MRSA.

• Study design: Open-label, randomized, comparator-controlled, multicenter, multinational clinical study

• Population: 1,200 hospitalized adult patients with cSSTI• Treatment arms:

Vancomycin (IV only) 1 g every 12 hours

Linezolid (oral or IV) 600 mg every 12

hours

OR

Linezolid vs Vancomycin for cSSTI Presumed or Known to Be Caused by MRSA

Weigelt JA et al. Infectious Diseases Society of America, 2003, poster 314. San Diego, CA.

If MSSA, vancomycin could be switched to

oxacillin/nafcillin/flucloxacillin (IV only) 1–2 g q6h or dicloxacillin (oral) 500

mg q6h

4- to 14-day treatment duration

Linezolid vs Vancomycin for cSSTI Clinical Cure Rates in Clinically Evaluable Subset

9094

0

20

40

60

80

100

Cli

nica

l cur

e ra

te (

%)

Linezolid 600 mg q12h IV/ PO Vancomycin 1g q12h IV*

436/ 462 394/ 436

P=0.023


Linezolid vs Vancomycin for cSSTIClinical Cure Rates in MRSA Subgroup

84

94

0

20

40

60

80

100

Clin

ical

cur

e ra

te (%

)

Linezolid 600 mg q12h IV/ PO Vancomycin 1g q12h IV*

*P=0.011

126/134

112/134


Linezolid Reduces LOS vs Vancomycinin cSSTI due to MRSA

Study Sample (linezolid/vancomycin)

Linezolid Vancomycin P Value

ITT (592/588) 7.4 9.8 <0.0001

CE (491/472) 7.4 9.9 <0.0001

ME (349/334) 7.6 9.8 <0.0001

MRSA (143/146) 8.1 10.7 0.0026

Mean LOS (days)

CE=clinically evaluable; ITT=intent-to-treat; LOS=length of stay; ME=microbiologically evaluable.Weigelt JA et al. Infectious Diseases Society of America; 2003, poster 315. San Diego, CA.

CE=clinically evaluable; ITT=intent-to-treat; ME=microbiologically evaluable; MITT=modified intent-to-treat.

Linezolid vs Vancomycin for cSSTI IV Antibiotic Treatment Days

1.9 2 1.9 2 1.8

9 9.19.9 9.9

12.6

0

2

4

6

8

10

12

14

ITT MITT CE ME MRSA

Sample population

Linezolid Vancomycin

Du

rati

on

of

IV t

reat

men

t (d

ays)


Cost Effectiveness of Linezolid vs Vancomycin in cSSTI

0

1000

2000

3000

4000

5000

6000

COST

($)

$4,143

CI (3,750–4,576)

$5,187

CI (4,691–5,714)

2003 Per diem hospital cost, administration of IV therapy, wholesale acquisition cost

Linezolid Vancomycin

Fleming T, ed. Red Book. 2004 edition. Montvale NJ: Thompson PDR;2004.

Linezolid vs Vancomycin for Surgical Site Infection (SSI )

Total Patients With cSSTI1,200

Total Patients With SSI135

Linezolid 66

Vancomycin69

-Weigelt J et al.: Am J Surg 2004;188:760-766.

Linezolid vs Vancomycin in SSIStudy Population

Study Population Linezolid

(n, %)

Vancomycin

(n, %)

All patients 66 (100) 69 (100)

MRSA 34 (52) 31 (45)

Baseline demographics:No significant difference

Baseline comorbidities/MRSA risk factors:No significant difference


Linezolid vs Vancomycin in SSI:Clinical Cure Rates at TOC

87

98

0

20

40

60

80

100

52/53 47/54

Clin

ical

cur

e ra

te (%

)

Linezolid 600 mg q12h IV/ PO Vancomycin 1g q12h IV

P=0.06


Linezolid vs Vancomycin in SSI: Microbiological Cure Rates at TOC

58

84

0

20

40

60

80

100

41/ 49 28/ 49

Clin

ical

cur

e ra

te (%

)


P=0.007


Linezolid vs Vancomycin in SSI:Microbiological Cure Rates at TOC in MRSA

Pts.

48

87

0

20

40

60

80

100

26/ 30 14/ 29

Clin

ical

cur

e ra

te (%

)


P=0.002


Daptomycin for cSSSIs

• Phase III: 2 international, multicenter, randomized, double-blind (evaluator blinded) studies (Studies 9801 & 9901):– Daptomycin (4 mg/kg IV qd) vs 1 of 2 comparators:

• Vancomycin (1 g q12h)

• Synthetic penicillin (4–12 g/d in 4 daily doses)

• Primary endpoint was safety and efficacy • Both studies demonstrated equivalence of

daptomycin to the comparator

Arbeit RD et al. Clin Infect Dis. 2004;38:1673-1681.

Daptomycin Efficacy• Design: 2 randomized, multinational, multicenter investigator-blinded studies• Daptomycin 4 mg/kg IV q24h or vancomycin 1 g IV q12h or a semisynthetic penicillin

(nafcillin, oxacillin, cloxacillin, flucloxacillin)

Type of Infection Daptomycin

No. of Pts (Success rate %)

Comparator*

No. of Pts (Success rate %)

Wound infection 169 (84%) 180 (87%)

Major abscess 102 (92%) 92 (88%)

Ulcer infection 47 (66%) 56 (70%)

Other infection† 47 (79%) 58 (83%)

*Comparator was vancomycin or a semisynthetic penicillin.†Other infections included complicated cellulitis, major abscess, or traumatic wound infection.

Clinical Success Rate: CE Population

Arbeit RD et al. Clin Infect Dis. 2004;38:1673-1681.

Comparison of MRSA Antimicrobials

Unfamiliarity and cost, reversible hematologic abnormalities, resistance (ie, VRE with prolonged use)

Limited indications, acquisition cost, myalgia, not effective for pneumonia

Infusion site inflammation, myalgias, arthralgias, and resistance

Toxicity, resistance (VRE, VISA, VRSA)

Disadvantages

Potential for less resistance

“Faster cure” (rapidly cidal)

QD

Parenteral

cSSSI

Daptomycin

Oral dosingremoval of catheters, early discharge, evidence of superiority to vancomycin in cSSTI

Alternative to vancomycin

FamiliarityAdvantages

“Gets patients home”“Works when vancomycin won’t”

“Cheap”Sales pitch

BIDq8-12hVariable depending upon renal function

Dosing

Parenteral, oralParenteral (central?)ParenteralRoute(s)

cSSSI and pneumoniacSSSI (not MRSA)MultipleFDA approved for MRSA

LinezolidQuinupristin/ Dalfopristin

Vancomycin

Summary

• SSI is a preventable morbidity• Gram-positive organisms are the primary pathogens

– MRSA increasing

• Treatment alternatives in MRSA SSIs and cSSTIs– Vancomycin

– Linezolid

– Daptomycin

– Quinupristin/dalfopristin*


Documents

Surgical Site Infection: New Solutions to a Continuing Problem R. Lawrence Reed, II, MD, FACS, FCCM Professor of Surgery Loyola University Medical Center