Medication Summary
The choice of antibiotic depends on 2 factors—the patient and the known or probable infecting microorganism. Patient factors include allergies, hepatic and renal function, severity of disease process, interaction with other medication(s), and age. In women, pregnancy and breastfeeding must be considered.
Antibiotics
Class Summary
Therapy must be comprehensive and cover all likely pathogens in the context of this clinical setting.
Cefazolin (Ancef, Kefzol, Zolicef)
First-generation semisynthetic cephalosporin that arrests bacterial cell wall synthesis, inhibiting bacterial growth. Primarily active against skin flora, including Staphylococcus aureus. Typically used alone for skin and skin-structure coverage. IV and IM dosing regimens are similar.
Erythromycin (EES, E-Mycin, Eryc)
Inhibits bacterial growth possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. For treatment of staphylococcal and streptococcal infections.
In children, age, weight, and severity of infection determine proper dosage. When bid dosing is desired, half-total daily dose may be taken q12h. For more severe infections, double the dose.
Cefoxitin (Mefoxin)
Second-generation cephalosporin indicated for gram-positive cocci and gram-negative rod infections. Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond to cefoxitin.
Cefotetan (Cefotan)
Second-generation cephalosporin indicated for infections caused by susceptible gram-positive cocci and gram-negative rods.
Dose and route of administration depend on condition of patient, severity of infection, and susceptibility of causative organism.
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Wound infection due to disturbed coagulopathy. This patient has a pacemaker (visible below right clavicular space) and had previous cardiac surgery (median sternotomy wound visible) for a rheumatic mitral valve disorder, which was replaced. The patient was taking anticoagulants preoperatively. Despite converting to low-molecular weight subcutaneous heparin treatment and establishing normal coagulation studies, she developed a postoperative hematoma with subsequent wound infection. She had the hematoma evacuated and was administered antibiotic treatment as guided by microbiological results, and the wound was left to heal by secondary intention.
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Abscess secondary to a subclavian line.
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Definitions of surgical site infection (SSI).
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Factors that affect surgical wound healing.
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Large ulceration in a tattoo. A 33-year-old man presented with a superficial ulceration about 4 weeks after a red tattoo on his forearm. Microbial swabs remained negative. His medical history was uneventful and he was in good general health. No reason for this uncommon reaction could be identified. Image courtesy of the National Institutes of Health.
Tables
- Table 1. Pathogens Commonly Associated with Wound Infections and Frequency of Occurrence [8]
- Table 2: Surgical Wound Classification and Subsequent Risk of Infection (If No Antibiotics Used) [8, 10]
- Table 3. Recommendations for Prophylactic Antibiotics as Indicated by Probable Infective Microorganism Involved [8, 30]
- Table 4. Predictive Percentage of SSI Occurrence by Wound Type and Risk Index* [31]
- Table 5. American Society of Anesthesiologists (ASA) Classification of Physical Status [32]
- Table 6. Data Support Recommendations
Pathogen |
Frequency (%) |
Staphylococcus aureus |
20 |
Coagulase-negative staphylococci |
14 |
Enterococci |
12 |
Escherichia coli |
8 |
Pseudomonas aeruginosa |
8 |
Enterobacter species |
7 |
Proteus mirabilis |
3 |
Klebsiella pneumoniae |
3 |
Other streptococci |
3 |
Candida albicans |
3 |
Group D streptococci |
2 |
Other gram-positive aerobes |
2 |
Bacteroides fragilis |
2 |
Classification |
Description |
Infective Risk (%) |
Clean (Class I) |
Uninfected operative wound No acute inflammation Closed primarily Respiratory, gastrointestinal, biliary, and urinary tracts not entered No break in aseptic technique Closed drainage used if necessary |
< 2 |
Clean-contaminated (Class II) |
Elective entry into respiratory, biliary, gastrointestinal, urinary tracts and with minimal spillage No evidence of infection or major break in aseptic technique Example: appendectomy |
< 10 |
Contaminated (Class III) |
Nonpurulent inflammation present Gross spillage from gastrointestinal tract Penetrating traumatic wounds < 4 hours Major break in aseptic technique |
About 20 |
Dirty-infected (Class IV) |
Purulent inflammation present Preoperative perforation of viscera Penetrating traumatic wounds >4 hours |
About 40 |
Operation |
Expected Pathogens |
Recommended Antibiotic |
Orthopedic surgery (including prosthesis insertion), cardiac surgery, neurosurgery, breast surgery, noncardiac thoracic procedures |
S aureus, coagulase-negative staphylococci |
Cefazolin 1-2 g |
Appendectomy, biliary procedures |
Gram-negative bacilli and anaerobes |
Cefazolin 1-2 g |
Colorectal surgery |
Gram-negative bacilli and anaerobes |
Cefotetan 1-2 g or cefoxitin 1-2 g plus oral neomycin 1 g and oral erythromycin 1 g (start 19 h preoperatively for 3 doses) |
Gastroduodenal surgery |
Gram-negative bacilli and streptococci |
Cefazolin 1-2 g |
Vascular surgery |
S aureus, Staphylococcusepidermidis, gram-negative bacilli |
Cefazolin 1-2 g |
Head and neck surgery |
S aureus, streptococci, anaerobes and streptococci present in an oropharyngeal approach |
Cefazolin 1-2 g |
Obstetric and gynecological procedures |
Gram-negative bacilli, enterococci, anaerobes, group B streptococci |
Cefazolin 1-2 g |
Urology procedures |
Gram-negative bacilli |
Cefazolin 1-2 g |
At Risk Index |
Predictive Percentage of SSI |
0 |
1.5 |
1 |
2.9 |
2 |
6.8 |
3 |
13.0 |
*Hospital Infection Control Practices Advisory Committee (HICPAC) recommendations (partial) for the prevention of SSIs, April 1999 (non–drug based) |
|
ASA Score |
Characteristics |
1 |
Normal healthy patient |
2 |
Patient with mild systemic disease |
3 |
Patient with a severe systemic disease that limits activity but is not incapacitating |
4 |
Patient with an incapacitating systemic disease that is a constant threat to life |
5 |
Moribund patient not expected to survive 24 hours with or without operation |
Category |
Description |
Category IA |
Well designed, experimental, strong; recommended (category I*) clinical or epidemiological best practice; should be studies; adapted by all practices |
Category IB |
Some experimental, fairly strong; recommended (category II*) clinical or epidemiological best practice; should be studies and theoretical grounds; adapted by all practices |
Category II |
Fewer scientific supporting data; limited to specific nosocomial (category III*) problems |
No recommendation |
Insufficient scientific personnel judgment for use (category III*) supporting data |
*Previous nomenclature of 1992 CDC guidelines |
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