ANTIBIOTICS AND WOUNDS
| SURGICAL ANTIBIOTIC PROPHYLAXIS IN THE 21st CENTURY—Hiram C. Polk, Jr., Ben A. Reid, Sr., Professor
and Chairman, Department of Surgery, University of Louisville, School of Medicine, Louisville, KY
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| Indications for antibiotic prophylaxis: clean surgery to implant foreign body; biliary tract surgery in elderly, diabetics,
obese patients, or that will involve common duct; any procedure that invades alimentary tract; not necessary in majority of
elective laparoscopic procedures (eg, cholecystectomy) in young, otherwise healthy, patients
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 | Surgical “time out”: opportunity to assess need for antibiotic prophylaxis and to verify dosage, administration, and concurrent
therapies in individual patient
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| Cephalosporin drug of choice: cefazolin, cefoxitin, or cefotetan 2 g 30 min before surgery (speaker cautions against
weight-based dosing); never use new drugs for prophylaxis (too dangerous); contraindicated in β-lactam allergy, but can
use in penicillin allergy (do not overuse vancomycin in β-lactam–allergic patients)
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| Conditions that do not require prophylaxis: procedures in which chance of allergic reaction greater than chance
of wound infection; these include—skin cancer; parathyroid and thyroid procedures; hernia repair without prosthetic
material; breast surgery, unless breast irradiated
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| Approach to high-risk patient: literature recommends combining systemic antibiotic (administered intravenously [IV])
with less expensive topical antibiotic in wound (eg, polysporin) at closure
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| When to stop antibiotic: most data suggest 1 or 2 doses sufficient; speaker recommends continuing 16 to 18 hr postoperatively,
but “don’t give prophylactic antibiotics into the second day”
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| Important principles of antibiotic therapy: bigger doses for shorter time; fever—beneficial, so do not order antipyretics;
perform work-up to determine cause; drug fever third most common cause of fever in surgical patients;
pneumonia—ongoing problem in surgical patients; obtain culture via broncoscopy before initiating antibiotic therapy
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| Methicillin-resistant Staphylococcus aureus (MRSA): in 2005, more cases of community-acquired MRSA (CA-
MRSA) than hospital-acquired; parenteral vancomycin drug of choice, but must be dosed carefully to avoid resistance;
oral linezolid (Zyvox; new drug; almost as effective orally as parenterally) recommended for outpatient use
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| Vancomycin-resistant enterococcus (VRE): manifestation of poor institutional antibiotic use (broad-spectrum
drugs used for too long in too many patients); requires washing down walls and fumigating building
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| Fungal infections (Candida): real problem in sick surgical patient; results from multiple antibiotic use; measures—1)
stop all systemic broad-spectrum antibiotics; 2) regulate blood glucose; 3) remove foreign bodies from patient, including
central venous catheter; 4) repopulate gastrointestinal (GI) tract with normal organisms
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| Clostridium difficile colitis: can be fatal; antibiotic-induced; takes only few doses to trigger; treat immediately, eg, with
metronidazole
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| Oral vs parenteral antibiotics: little or no place for oral antibiotics in general surgery, apart from economic benefits
of Zyvox in home care
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| Old vs new drugs: avoid new drugs
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| WOUND CARE—Bruce Potenza, MD, Associate Professor of Surgery, University of California, San Diego, School of Medicine
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| Stages of wound healing: hemostasis—simple laceration or abrasion results in coagulation and vasoconstriction mediated
by endogenous norepinephrine; local vessels constrict and clot forms; after hemostasis with clotting, secondary vasodilation
occurs with aid of mediators that provide serotonin; inflammation—circulating monocytes convert to
macrophages that enter and (with neutrophils) begin to clean up wound, releasing growth factors (eg, vascular endothelial
growth factor [VEGF], fibroblast growth factor, platelet recruitment factors; active under fibrin clot) and local and systemic
cytokines that recruit other cells; proliferation—migration and proliferation of vascular pathways (angiogenesis);
fibroblast proliferation leads to collagen formation, wound contraction, closure, and epithelialization; remodeling—
occurs weeks to 1 yr after wound healed; wound continues to contract and change color, texture, and amount of contraction
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| Focus of research: time sequence of cell types, ie, switch from platelets and neutrophils in early phases to predominance
of macrophages that recruit fibroblasts that create collagen and do remodeling
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| Wound strength: increases over months after wound closure; tensile strength of healed wound only 70% that of original tissue;
in surgical patients, stresses on tensile strength of wound applied early (24-48 hr after closure) as activity resumes
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| Characteristics of an ideal bandage: protection; absorption of tissue exudate; compression for local edema; nonadherence;
maintenance of wound moisture and warmth; promotion of oxygen gradient to stimulate angiogenesis
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| Mechanics of occlusion: bandaged wound re-epithelializes and heals much faster than open wound, in part because
scab inhibits re-epithelialization and traps bacteria and used-up cytokines and leukotrienes in wound; need wound occlusion
that wicks off exudate and toxic metabolic byproducts; local growth factors must stay in wound while functional and
be wicked out when they start to degrade
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| Types of wounds: simple incisional wound; road rash from motor vehicle crash; soft tissue contusion; draining wound
from which exudate must be wicked away; wound with embedded foreign material; burn wound; wound with soft-tissue
loss; temporary closure, eg, damage-control surgery in which aim simply to close abdomen and apply sterile coverage;
desiccated wound in need of rehydration
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| Nonabsorptive occlusive bandages: Xeroform bandage—petroleum-based, 3% bismuth, some antimicrobial properties;
relatively occlusive (ensure wound does not become wet); for simple road rash or skin donor sites, good bandage that
will dry and peel off like scab; Telfa pads—sometimes used postoperatively with antibiotic ointment (Telfa pad, sterile
gauze, and tape form typical 3-part bandage); gauze bandages—Vaseline gauze; Adaptic gauze; conforming gauze (nylon
sleeve acts like screen to prevent wound from sticking to outer bandage); others—Tegaderm; Bogota bag for abdomen
trauma surgeon cannot close
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| Absorptive bandages: simple gauze bandages (eg, cotton gauze, kerlix gauze, prolex gauze); foam pads—
hydrophobic polyurethane foam sheets; pieces of foam gauze that often come with adhesive backing; wick away exudate;
can be left on some wounds ≈3 days
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| Nonbiologic bandages: wound vacuum assisted closure (VAC)—occlusive bandage that wicks away exudate by suction,
keeps wound warm, and comes with silver-impregnated sponges for antimicrobial effect; case—necrotizing fascitis;
speaker’s team covered with wet-to-dry bandages for 48 hr due to high concentrations of streptococci; wound VAC positioned
circumferentially around leg with 3 suction catheters; after granulation under way, bandage changed every 5 to 7 days
in operating room; aim to promote formation of bed for later grafting
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| Occlusive bandages: nonbiologic— alginates (Algiderm; seaweed derivative that comes in ribbons and ropes; wick
out fluid; change when saturated); biologic—allograft (donor skin), xenograft (pig skin); Biobrane—bioengineered silicone
film on nylon fabric; can stay on wound ≤30 days; grows into wound; surgically removed before skin grafting
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| Skin substitutes: TransCyte—made on matrix of Biobrane and impregnated with neonatal fibroblasts; carries thin layer of
silicone; use on second-degree, superficial, and deep burns; dries to form bandage for 10 to 14 days; improves scarring and accelerates
healing; believed to downregulate inflammatory process on wound bed; Integra—leaves part of itself on wound and
forms neodermis that allows flexibility during deep debridement; stays on for 2 to 4 wk; leaves thin neodermis onto which thin
skin graft applied; provides flexibility and elasticity under graft; freeze-dried and pasteurized dermis now available in large
sheets as high-tensile strength material for use in hernia surgery and infected wound beds; sheet repopulated by patient’s own
fibroblasts
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| Creams, ointments, and solutions: Sulfamylon solution provides antibacterial properties to normal saline wet-to-dry
bandages; Silvadene cream now available with antibiotic
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| Future directions: use of cultured epidermal cells still in its infancy; fragile and lacking elasticity of connective tissue;
need sturdier, better dermal substitutes
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| PROPHYLACTIC ANTIBIOTICS: WHY AND WHEN?—John F. Fisher, MD, Professor of Medicine, Medical College of Georgia,
Augusta, GA
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| Causes of infection: patient factors—extremes of age; diabetes; smoking; urinary tract infection or remote infection at
time of procedure; obesity; malnutrition and low albumin; corticosteroid therapy; previous long-term hospitalization; irradiation
of site of procedure; S aureus colonization; procedural factors—lack of preoperative antiseptic showering (eg, emergency);
razor use for hair removal; poor skin preparation; improper antimicrobial prophylaxis; perioperative hypothermia or
hypoxemia; poor surgical technique; failure to redose antibiotics in long procedures; increased operating room traffic; break
in surgical technique; improper use of flash sterilization of instruments; excessive use of electrocautery; need for intraoperative
blood transfusion; microbial factors—determine organism involved, how much inoculated into wound, ability of organism
to adhere to tissue, and invasive potential of organism; also determine whether perioperative antimicrobial
prophylaxis properly done
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| Classifying wound for prophylaxis: clean wound—nontraumatic; no inflammation; no break in surgical technique;
respiratory, GI, or genitourinary (GU) tract not entered; clean-contaminated wound—nontraumatic but may involve
minor break in technique or entry into respiratory, alimentary, or GU tracts but without significant spillage;
contaminated wound—fresh traumatic wound from relatively clean source; major break in technique; gross spillage from
GI tract or entrance into infected biliary or GU tract; dirty wound—old traumatic wound with retained dead tissue; foreign
body or fecal contamination of previously infected wound; wound involving foreign body, devitalized viscus, or pus
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| Litany of pathogens: clean wound—“staphylococci, staphylococci, staphylococci”; major risk factor for infection S aureus
colonization of anterior nares; overall risk for infection in clean wound 1.3% to 3%; however, in diabetics or hemodialysis
patients, colonization rates of anterior nares >50%; clean-contaminated or contaminated wounds—consider normal
flora of viscus entered; infection risk ≈5% if clean contaminated, ≈10% if contaminated, and 20% to 25% if dirty; oropharynx
and esophagus—1010 bacteria; >200 species in mouth include aerobes (eg, Streptococcus salivarius, Streptococcus
mutans, Streptococcus sanguis; S aureus found mostly in nares and nasopharynx, not common in oropharynx) and
anaerobes; stomach—mostly swallowed oral flora; some acid-tolerant organisms (mostly streptococci) that survive hydrochloric
acid (HCl) and other pH factors, eg, use of proton pump inhibitors and antacids; small intestine—population of organisms
much higher in proximal end than in stomach, mostly gram-positive species, eg, Lactobacillus, enterococcus;
colon—polymicrobial flora; 400 species, mostly Escherichia coli, Klebsiella, Proteus, streptococcus, and enterococcus
in aerobic group, and Bacteroides and Fusobacterium species in anaerobic group
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| Risks of antimicrobial prophylaxis: toxic or allergic reaction; emergence of resistant bacteria; superinfection; expense
of unwise antibiotic choices or prolonged therapy
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| Indications for prophylaxis: procedures with high infection rates; procedures involving implantation of prosthetic
material; procedures in which infection would lead to disastrous consequences; pick regimen targeting most likely pathogen
and do not try to cover every possible pathogen
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| Clean procedures: S aureus primary target; cefazolin traditional choice, 1 to 2 g intravenously (IV) in single dose; cefuroxime
also approved; vancomycin in patients allergic to β-lactams
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| Special indications: in clean procedures for diabetics and renal patients on dialysis, check for positive nasal culture for S
aureus; if found, consider intranasal mupirocin evening before and day of surgery and continue for 5 days postoperatively
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| Clean-contaminated procedures: for gastroduodenal procedures—staphylococci and streptococci primary targets;
cefazolin or second-generation cephalosporin and consider repeating dose every 12 hr for 2 to 3 days; biliary
procedures—cephalosporin or fluorinated quinolone; possibly repeat dose in 12 and 24 hr; gastroduodenal surgery—
infection risk high if patient uses H2 blocker, has ileus, or is morbidly obese
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| Endoscopic retrograde cholangiopancreatography (ERCP): controversial; no benefit from single-dose piperacillin,
according to one randomized trial; if no obstruction present, no need for prophylaxis; if obstruction present, antibiotic
treatment rather than prophylaxis; pick fluorinated quinolone, second- or third-generation cephalosporin, or
piperacillin 4 g IV before procedure (speaker prefers; covers enterococcus); partially obstructed biliary trees colonized,
so focus on therapy
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| Timing of prophylaxis: single dose just before procedure; second dose not necessary, but advisable if antibiotic has
relatively short half-life (eg, cefoxitin), prolonged surgery expected, or patient has major blood loss; belly abscess—
avoid prophylaxis (start empiric therapy in operating room and adjust when culture results available)
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| Prophylaxis for endocarditis with GI endoscopy: risk relatively low
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| High-risk cardiac lesions: prosthetic valves; surgically constructed pulmonary shunts or conduits; cyanotic congenital
heart disease, especially tetralogy of Fallot, or history of endocarditis
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| High risk for bacteremia: dilation of esophageal strictures, (bouginage), ERCP for obstruction; prophylaxis can—
decrease risk for peristomal wound infection after percutaneous endoscopic gastrostomy; decrease cholangitis risk after
ERCP for obstruction; decrease infections in bleeding varices, fine needle aspiration of pancreatic cysts
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| Patients at high risk: surgeon really going after streptococci, especially enterococcus; ampicillin plus gentamicin given 30
min before procedure, then 1 g amoxicillin po 6 hr later or vancomycin 1 to 2 hr before procedure; with intermediate-
risk patients, argument for prophylaxis less stringent
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Educational Objectives
| The goal of this program is to educate the listener about antibiotic prophylaxis in surgery and wound healing and
wound care. After hearing and assimilating this program, the clinician will be better able to:
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| List patients who are candidates for surgical antibiotic prophylaxis.
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| Name the 4 infections of most concern to surgeons and hospitals and the drug of choice for each.
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| Describe the process of wound healing and discuss clean, clean-contaminated, contaminated, and dirty
wounds.
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| Discuss the ideal characteristics of a bandage for healing.
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| Name and discuss some biologic alternatives to human skin.
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Discussed on This Program
Amoxicillin (several trade names)
Ampicillin [Principen]
Cefazolin sodium [Ancef, Zolicef]
Cefdinir [Omnicef]
Cefotetan disodium [Cefotan]
Cefoxitin sodium [Mefoxin]
Gentamicin sulfate (several trade names)
Linezolid [Zyvox]
Piperacillin sodium [Pipracil]
Vancomycin [Vancocin, Vancoled]
Suggested Reading
Attinger CE et al: Clinical approach to wounds: debridement and wound bed preparation including the use of
dressings and wound-healing adjuvants. Plast Reconstr Surg 117:72S, 2006; Bennett NJ et al: Surgical antibiotic
prophylaxis in smaller hospitals. ANZ J Surg 76:676, 2006; Brebbia G et al: Surgical site infections in day surgery
settings. Surg Infect (Larchmt) 7 Suppl 2:S121, 2006; Butter A et al: Vacuum-assisted closure for wound management
in the pediatric population. J Pediatr Surg 41:940, 2006; De Lalla F: Perioperative antibiotic prophylaxis: a
critical review. Surg Infect (Larchmt) 7 Suppl 2:S37, 2006; Glasberg SB et al: Use of regenerative human acellular
tissue (AlloDerm) to reconstruct the abdominal wall following pedicle TRAM flap breast reconstruction surgery.
Plast Reconstr Surg 118:8, 2006; Hampton S: A small study in healing rates and symptom control using a new
sheet hydrogel dressing. J Wound Care 13:297, 2004; Hassan Z et al: Punctate scarring from use of porous Biobrane.
Burns 32:258, 2006; Huang WS et al: Use of vacuum-assisted wound closure to manage limb wounds in patients
suffering from acute necrotizing fasciitis. Asian J Surg 29:135, 2006; Melkun ET et al: The use of
biosynthetic skin substitute (Biobrane) for axillary reconstruction after surgical excision for hidradenitis suppurativa.
Plast Reconstr Surg 115:1385, 2005; Moiemen NS et al: Reconstructive surgery with Integra dermal regeneration
template: histologic study, clinical evaluation, and current practice. Plast Reconstr Surg 117:160S, 2006; Parsons D
et al: Silver: clarifying the claims. Ostomy Wound Manage 52:12,14; author reply 14, 16, 2006; Pocock SB et al:
Inappropriate use of antibiotic prophylaxis to prevent infective endocarditis in obstetric patients. Obstet Gynecol
108:280, 2006; Shepherd BR et al: Vascularization and engraftment of a human skin substitute using circulating
progenitor cell-derived endothelial cells. FASEB J 20:1739, 2006; Suzuki Y et al: Infective endocarditis with congenital
heart disease. Jpn J Thorac Cardiovasc Surg 54:297, 2006
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue,
Dr. Polk reported he is one of the surgeon owners of Quality Surgical Solutions (QSS) PLLC, and Dr. Fisher reported
he is a minor stockholder in Pfizer Inc. and member of its Speakers’ Bureau. Dr. Potenza reported nothing to disclose.
Dr. Polk addressed the 35th Annual Postgraduate Course in Surgery, held April 27-29, 2006, in Charleston, SC, and
sponsored by the Medical University of South Carolina. Dr. Potenza spoke at the California Trauma Conference,
held January 26-28, 2006, in San Diego, CA, and sponsored by the University of California at San Diego, Los Angeles,
Davis, San Francisco, and Fresno, as well as by Scripps Mercy Hospital, Scripps Memorial Hospital, Sharp Memorial
Hospital, Palomar Medical Center, and Children’s Hospital of San Diego. Dr. Fisher addressed Medical and
Surgical Approaches to GI Disorders, held July 10-14, 2006, in Kiawah Island, SC, and sponsored by the Medical
College of Georgia, School of Medicine, Division of Continuing Medical Education. The Audio-Digest Foundation
thanks the speakers and the sponsors for their cooperation in the production of this program.
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