Antimicrobial prophylaxis in surgery

Antimicrobial prophylaxis refers to the prevention of infection complications following surgical procedures. Such infections are observed with relative frequency, even after "sterile" operations. An estimated 5 to 10 percent of hospitalized patients undergoing otolaryngology ("head and neck") surgery acquire a nosocomial ("hospital") infection, which adds a substantial cost and an average of 4 extra days to the hospital stay. Urinary tract infections are the most common nosocomial infections (accounting for more than 7 million physician visits every year in the United States), and are second in seriousness to respiratory infections.

Antibiotics are effective in reducing the occurrence of such infections, even in "sterile" operative cases, as long as the drugs are properly selected and administered. Patients should be selected for prophylaxis if the medical condition or the surgical procedure is associated with a considerable risk of infection or if a postoperative infection would pose a serious hazard to the patient's recovery and well-being.[1]

Microbial infections

Local wound infections (superficial or deep-sided), urinary tract infections (caused by bladder catheter, inserted for surgery), and pneumonia (due to impaired breathing/coughing, caused by sedation and analgesics during the first few hours of recovery) may endanger the health of patients after surgery. Visibly worse are postoperative bacterial infections at the site of implanted foreign bodies (sutures, ostheosynthetic material, joint replacements, pacemaker implants, ect). Often, the outcome of the procedure in question and even the life of the patient is at risk.

Prevention of microbial infection

Worldwide experience with antimicrobial prophylaxis in surgery has proven to be effective and cost-efficient, both avoiding severe patient suffering while saving lives (provided the appropriate antibiotics have been carefully chosen and used to the best of current medical knowledge).

Antibiotic selection

A proper regimen of antibiotics for perioperative prophylaxis of septic complications decreases the total amount of antimicrobials needed and eases the burden on hospitals. The choice of antibiotics should be made according to data on pharmacology, microbiology, clinical experience and economy. Drugs should be selected with a reasonable spectrum of activity against pathogens likely to be encountered, and antibiotics should be chosen with kinetics that will ensure adequate serum and tissue levels throughout the risk period.

For prophylaxis in surgery, only antibiotics with good tolerability should be used. Cephalosporins remain the preferred drugs for perioperative prophylaxis due to their low toxicity. Parenteral systemic antibiotics seem to be more appropriate than oral or topical antibiotics because the chosen antibiotics must reach high concentrations at all sites of danger. It is well recognized that broad-spectrum antibiotics are more likely to prevent gram-negative sepsis. New data demonstrate that third generation cephalosporins are more effective than first and second generation cephalosporins if all perioperative infectious complications are taken into consideration.

Duration of antibiotic administration

Prophylaxis of the shortest possible duration should be aimed at in order to minimize the risk of serious adverse effects or dangerous development of resistance. The minimum frequency of administration is the single dose, which usually produces fewer adverse effects than the multiple dosage and at the same time often represents the most economical form of administration.

The goal of antimicrobial prophylaxis is to achieve sufficient antibiotic tissue concentrations prior to possible contamination in the relevant tissues and to ensure adequate levels throughout the operative procedure to prevent subsequent bacterial growth. Of crucial importance for success in surgical prophylaxis is the timing of administration of short-acting antibiotics, as persistent antimicrobial activity throughout the entire operation is essential; the longer a surgical procedure lasts, the longer an appropriate antibiotic tissue level must be maintained. This can be achieved either by repeated administrations or by giving a single dose of a suitable long-lasting antimicrobial.

Also, by extending the antimicrobial cover some hours beyond the duration of the actual surgical procedure, it is possible to reduce the perioperative infection rates of urinary and respiratory septic complications considerably (provided an adequately broad spectrum antibiotic prophylaxis is chosen).

Advantages of long-acting antibiotics

Long-acting, broad-spectrum antibiotics offer the following advantages by comparison to short-acting antimicrobials in perioperative prophylaxis:

• A single dose covers the whole perioperative risk period - even if the operation is delayed or long-lasting - and with regard to respiratory and urinary tract infections
• Repeat administrations for prophylaxis are not necessary, so that additional doses are less likely to be forgotten (an advantage of practical value in a busy working situation such as a hospital)
• Less risk of development of resistance and less side effects
• Increased compliance and reduced errors of administration
• Possibly better cost-effectiveness (less material and labor cost, less septic perioperative complications)

Antimicrobial Prophylaxis

• Antimicrobial Prophylaxis

Procedure	Causative etiologies	Recommended antimicrobials	Usual adult dosage	Comments
Cardiovascular
	Staphylococcus aureus, Staphylococcus epidermidis	Cefazolin	1-2 g IV	Antibiotic prophylaxis has been proved beneficial in the following patients: reconstruction of abdominal aorta, procedures on the leg that involve a groin incision, any vascular procedure that inserts prosthesis/foreign body, lower extremity amputation for ischemia, cardiac surgery, permanent pacemakers, heart transplant. The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses. Some experts recommend an additional dose when patients are removed from bypass during open-heart surgery.
		Cefuroxime	1.5 g IV	Some experts recommend an additional dose when patients are removed from bypass during open-heart surgery.
		Vancomycin	1 g IV	Vancomycin is preferable in hospitals with high frequency of MRSA, high risk patients, those colonized with MRSA or for pen-allergic patients. Clindamycin 900 mg IV is another alternative for pen-allergic or vanco-allergic patients. Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone.
		Mupirocine		Consider intranasal Mupirocine evening before, day of surgery and bid for 5 days post-op in patients with positive nasal culture for S. aureus. Mupirocine resistance has been encountered.
Gastrointestinal
Esophageal, gastroduodenal (includes percutaneous endoscopic gastrostomy - high risk only)	Enteric gram-negative bacilli, gram-positive cocci	High-risk only: Cefazolin, Cefoxitin, Ceftriaxone	Single-dose: 2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses. PEG placement: high-risk is marked obesity, obstruction, reduced gastric acid or reduced motility.
Biliary tract	Enteric gram-negative bacilli, enterococci, clostridia	High-risk only: Cefazolin, Cefoxitin or Cefotetan	1-2 g IV	High risk: age >70, acute cholecystitis, non-functioning gallbladder, obstructive jaundice or common duct stones. With cholangitis, treat as infection, not prophylaxis. The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses. Low-risk, laparoscopic: no prophylaxis.
		OR Ampicillin/Sulbactam	3 g IV
Endoscopic retrograde cholangiopancreatography		Ciprofloxacin	500 - 750 mg PO OR 400 mg IV 2 hours before procedure	Only needed if there is obstruction. Greatest benefit of prophylaxis occurs when complete drainage cannot be achieved.
		OR Piperaciline-Tazobactam	4.5 g IV 1 hour before procedure	Only needed if there is obstruction.
Colorectal	Enteric gram-negative bacilli, anaerobes, enterococci	Oral: Neomycin PLUS Erythromycin bases OR Metronidazole		In addition to mechanical bowel preparation, 1 g of Neomycin PLUS 1 g of Erythromycin at 1 PM, 2 PM and 11 PM or 2 g of Neomycin PLUS 2 g of Metronidazole at 7 PM and 11 PM the day before an 8 AM operation.
		Parenteral: Cefoxitin or Cefotetan	1-2 g IV
		OR Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		PLUS Metronidazole	0.5 g IV
		Ampicillin/Sulbactam	3 g IV
		Ertapenem	1 g IV	Ertapenem can be used if there is beta-lactam allergy. Other regimens include: Clindamycin 900 mg IV PLUS Gentamycin 5mg/kg OR Aztreonam 2 g IV OR Ciprofloxacin 400 mg IV.
Appendectomy, non-perforated	Same as for colorectal	Cefoxitin OR Cefotetan	1-2 g IV	For patients allergic to penicillins and cephalosporins, Clindamycin OR Vancomycin with either Gentamicin, Ciprofloxacin, Levofloxacin or Aztreonam is a reasonable alternative. Fluoroquinolones should not be used for prophylaxis in cesarean section.
		OR Cefazolin	1-2 g IV
		PLUS Metronidazole	0.5 g IV
Genitourinary
Cystoscopy alone	Enteric gram-negative bacilli, enterococci	High-risk only: Ciprofloxacin	500 mg PO OR 400 mg IV	Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use. AUA recommends prophylaxis for those with several potentially adverse host factors (e.g. advanced age, immunocompromised state, anatomic abnormalities, etc.).
		OR Trimethoprim-Sulfamethoxazole	1 DS tablet
Cystoscopy with manipulation or upper tract instrumentation	Enteric gram-negative bacilli, enterococci	Ciprofloxacin	500 mg PO OR 400 mg IV	Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use.
		OR Trimethoprim-Sulfamethoxazole	1 DS tablet	Viable alternative in populations with low rates of resistance.
Transrectal prostate biopsy	Enteric gram-negative bacilli, enterococci	Ciprofloxacin	500 mg PO 12 hours before biopsy and 12 hours after first dose.
Open or laparoscopic surgery	Enteric gram-negative bacilli, enterococci	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
Gynecologic and Obstetric
Vaginal, abdominal or laparoscopic hysterectomy	Enteric gram-negative bacilli, anaerobes, Gp B strep, enterococci	Cefazolin OR Cefoxitin OR Cefotetan	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses. For patients allergic to penicillins and cephalosporins, Clindamycin OR Vancomycin with either Gentamicin, Ciprofloxacin, Levofloxacin or Aztreonam is a reasonable alternative. Fluoroquinolones should not be used for prophylaxis in cesarean section. Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use.
		OR Ampicillin/Sulbactam	3 g IV	For patients allergic to penicillins and cephalosporins, Clindamycin OR Vancomycin with either Gentamicin, Ciprofloxacin, Levofloxacin or Aztreonam is a reasonable alternative. Fluoroquinolones should not be used for prophylaxis in cesarean section. Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use.
Cesarean section	Same as for hysterectomy	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses. For patients allergic to penicillins and cephalosporins, Clindamycin OR Vancomycin with either Gentamicin, Ciprofloxacin, Levofloxacin or Aztreonam is a reasonable alternative. Fluoroquinolones should not be used for prophylaxis in cesarean section. Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use.
		Clindamycin	900 mg IV	Use as alternative method to Cefazolin and associated with Gentamicin 5 mg/kg IV OR Tobramycin 5 mg/kg IV single dose.
Abortion, surgical	Same as for hysterectomy	Doxycycline	300 mg PO	Divided into 100 mg before the procedure and 200 mg after.
Head and Neck Surgery
Incisions through oral or pharyngeal mucosa	Anaerobes, enteric gram-negative bacilli, S. aureus	Clindamycin	600 mg - 900 mg IV	Clean, uncontaminated head and neck surgery does not require prophylaxis. If using Clindamycin, consider associating Gentamicin 5 mg/kg IV single dose.
		OR Cefazolin	2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		PLUS Metronidazole	0.5 g IV
		OR Ampicillin/Sulbactam	3 g IV
Neurosurgery
	S. aureus, S. epidermidis	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		OR Vancomycin	1 g IV	Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone.
		Clindamycin	900 mg IV	Clindamycin can be used in clean, contaminated surgeries (cross sinuses, or naso/oropharynx). British recommend Amoxicilin-clavulanate 1.2 g IV OR Cefuroxime 1.5 g IV PLUS Metronidazole 0.5 mg g IV.
Ophthalmic
	S. aureus, S. epidermidis, streptococci, enteric gram-negative bacilli, Pseudomonas spp.	Gentamicin, Tobramycin, Ciprofloxacin, Gatifloxacin, Levofloxacin, Moxifloxacin, Ofloxacin OR Neomycin-gramicidin-polymyxin B	Multiple drops topically over 2 to 24 hours
		OR Cefazolin	100 mg subconjunctivally
Orthopedic
Hip arthroplasty, spinal fusion	S. aureus, S. epidermidis	Same as cardiac surgery
Total joint replacement (other than hip)	S. aureus, S. epidermidis	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		OR Vancomycin	1 g IV	Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone. If a tourniquet is to be used in the procedure, the entire dose of antibiotic must be infused prior to its inflation. For patients weighing >90 kg use Vancomycin 1.5 g IV as single dose OR Clindamycin 900 mg IV.
Open reduction of closed fracture with internal fixation	S. aureus, S. epidermidis	Ceftriaxone	2 g IV single dose
Thoracic (non-cardiac)
	S. aureus, S. epidermidis, enteric gram-negative bacilli, streptococci	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		OR Vancomycin	1 g IV	Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone.
		OR Ampicillin/Sulbactam	3 g IV	Due to increasing resistance of E. coli to fluoroquinolones and Ampicillin/Sulbactam, local sensitivity profiles should be reviewed prior to use.
Vascular
Arterial surgery involving· a prosthesis, the abdominal aorta, or a groin incision	S. aureus, S. epidermidis, enteric gram-negative bacilli	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		OR Vancomycin	1 g IV	Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone.
Lower extremity amputation for ischemia	S. aureus, S. epidermidis, enteric gram-negative bacilli, clostridia	Cefazolin	1-2 g IV	The recommended dose of Cefazolin is 1 g for patients who weigh <80 kg and 2 g for those ~80 kg. Morbidly obese patients may need higher doses.
		OR Vancomycin	1 g IV	Vancomycin can be used in hospitals in which methicillin-resistant S. aureus and S. epidermidis are a frequent cause of postoperative wound infection, in patients previously colonized with MRSA, or for those who are allergic to penicillins or cephalosporins. Rapid IV administration may cause hypotension, which could be especially dangerous during induction of anesthesia. Even when the drug is given over 60 minutes, hypotension may occur; treatment with Diphenhydramine (Benadryl, and others) and further slowing of the infusion rate may be helpful. Some experts would give 15 mg/kg of Vancomycin to patients weighing more than 751<g, up to a maximum of 1.5 g, with a slower infusion rate (90 minutes for 1.5 g). For procedures in which enteric gram-negative bacilli are common pathogens, many experts would add another drug such as an aminoglycoside (Gentamicin, Tobramycin or Amikacin), Aztreonam or a fluoroquinolone.

Resources

• Therapy in Otolaryngology
• Urinary track infection in adults Cleveland Clinic
• Antimicrobial prophylaxis Virginia-Maryland Regional College of Veterinary Medicine