The Role of Prophylactic Antibiotics in Preventing Perioperative Infection
Budi Setiawan
Department of Internal Medicine, Faculty of Medicine, University of Indonesia - dr. Cipto Mangunkusumo Hospital.
Jl. Diponegoro no. 71, Jakarta Pusat 10430, Indonesia.
Correpondence mail to: pipfkui@yahoo.com
ABSTRACT
With the increasing number of surgery or operation, perioperative infection has become one of problems that have been found more often. Surgical site infection is the most common perioperative infection causing increased hospitalization stay, high cost, morbidity and mortality rate. Infection occurs within 30 days after the operation on surgical site or within one year if implant is in place. Such infection may be prevented through several ways including some aspects of health-care provider, operating-room environment, and adequate preoperative preparation of the patients. Antibiotic prophylaxis is one of important modalities in preventing surgical site infection. Antibiotic prophylaxis administration significantly reduces the incidence of surgical site infection up to four-fold of decrease. Short-term antibiotic is given prior to incision in order to reduce the contamination of bacterial inoculums during surgery. The decision to administer antibiotic prophylaxis should be made by considering their risk and benefits. One of them includes utilization of the NNIS (National Nosocomial Infections Surveillance) score system, which considers three factors, such as wound class, ASA physical status scale, and duration of operation according to the NNIS Survey. The selection on timing and appropriately administered antibiotic prophylaxis is critical to maximize the benefits.
Key words: perioperative, surgical site infection, prophylaxis, antibiotic
INTRODUCTION
With the increasing number of surgery or operation, perioperative infection has become one of problems that have been found more often. It has been estimated that forty six million of surgical procedures are performed each year in the United States. Surgical site infection (SSI) is one of perioperative infection that has been mostly found.1-3 One to three of 1,000 patients who underwent surgical procedures had experienced surgical site infection.1 It results in prolonged hospital stays, which increases operational cost that should be endured by the patient; in addition to the high morbidity, disability and mortality rate.2-4 Therefore, more concern should be given on perioperative infection, especially on prevention.
DEFINITION AND CLASSIFICATION OF SURGICAL SITE INFECTION
Before the mid-19th century, surgical patients commonly developed postoperative fever, followed by purulent drainage from their surgical sites.4 Moreover, the infection frequently progress to sepsis and even death.4 For the surveillance of surgical site infection, we need a standardized terminology and classification.
By definition, surgical site infection is infection that occurs within 30 days after the operation on surgical site or within one year if implant is in place.1,4 The classification of surgical site infection categorizes the infection into three groups, namely the superficial incisional-, deep incisional-, and organ-space SSI.4 The classification is shown on Table 1.
THE RISK OF SURGICAL SITE INFECTION
The risk of SSI is highly associated with the classification of surgery performed. Classification of operative wounds and their risk of infection is shown on Table 2.
Until the late 1980s, the abovementioned classification has been frequently used to evaluate the risk of surgical site infection. However, such classification is not adequate since it does not consider other important factors 5 Some factors that may affect the risk of surgical site infection are duration of operation, operation techniques, the patient’s co-morbid medical condition, etc.
PREVENTING SURGICAL SITE INFECTION
In 1890s, Joseph Lister introduced the technique of asepsis and antisepsis for surgical procedures. It has significantly led to a decrease of incidence and severity of postoperative infection.4 Subsequently, a paradigm had arisen that surgical site infection could be prevented.4,5
Various techniques could be performed to prevent surgical site infection, starting from considering the aspect of health-care provider, environment of the operating room to the preoperative preparation for the patient. In the operating room, the health-care provider should wear special instruments such as standardized surgical attire, surgical mask, gloves and work cap. A good hand washing by using antiseptic has been proven to be effective in reducing the incidence of nosocomial infection. Moreover, the intraoperative operating room ventilation should be considered, including the table, ceiling and floor. Continued surveillance should also be performed to evaluate the level of microbial contamination in the operating room environment.
The sterilization of surgical instrument and equipment should be standardized. Finally, the preoperative
Table 1. Classification of surgical site infection (SSI)4
Superficial incisional SSI Infection involves only skin or subcutaneous tissue and at least one of the following:
- Purulent drainage from the superficial incision, with or without laboratory result.
- Isolated microorganism from a culture of fluid or tissue.
- On the surgical site: pain, swelling, heat or redness.
- Diagnosis of superficial incisional SSI established by surgeon or attending physician
Deep Incisional SSI Infection involves deep soft tissues such as fascia or muscle layer and at least one of the following:
- Purulent drainage from the deep incision but not from organ or organ space component
- A deep incision spontaneously dehisces or is deliberately opened by a surgeon when the patient has at least one of the following signs: fever (>380C), localized pain or tenderness.
- An abscess or other evidence of deep infection that is found on direct examination, by histopathologic or radiologic examination
- Diagnosis of deep incisional SSI made by a surgeon or attending physician
Organ or space SSI Infection involves organs or spaces, other than the incision site and at least one of the following:
- Purulent drainage from the organ or space
- Isolated microorganism from a culture of fluid or tissue
- An abscess or other evidence of deep infection that is found on direct examination or by histopathologic or radiologic examination
- Diagnosis of organ/space SSI by a surgeon or attending physician
Table 2. Classification of operation based on operative wound3-5
Classification of Operation Description Incidence of Surgical
Site Infection Class I Clean Uninfected operative wound, in which the respiratory, gastrointestinal and
genitourinary tracts were not entered; including incisional surgery due to blunt trauma.
<2%
Class II Clean-contaminated Elective operation of visceral organ; therefore it causes controlled surgical wound of respiratory, gastrointestinal and urinary tract involving biliary tract, appendix, vagina and oropharynx.
5 – 15%
Class III Contaminated Open surgical wound, including open cardiac massage, gastrointestinal surgery
and incision on location with non-purulent inflammation 15 – 30%
Class IV Dirty Surgery of old wounds with dead tissue and those that involve existing clinical infection or perforated bowel. The pathogens causing surgical site infection were present in the wound before the surgery.
>30%
preparation for the patient should be adequate. The surgical field should be cleaned from visible surface dirt and then antiseptic (povidone-iodine or chlorhexidine gluconate) should be applied.4
ANTIMICROBIAL PROPHYLAXIS
There have been numerous studies on antimicrobial prophylaxis to prevent surgical site infection. One of them is a study conducted by National Surgical Infection Prevention Project in 1967. It was a prospective, double-blind, randomized controlled trial in patients who underwent elective gastrointestinal surgery. In patients who had not received antibiotic prophylaxis, there was four-fold greater incidence of surgical site infection compared to patients who had received antibiotic prophylaxis.6
Antimicrobial prophylaxis refers to the administration of short-term antibiotics in surgical patients before the initiation of surgery. If there has been a sign of infection, the administered antibiotic is intended for therapy rather than prevention. For example, antibiotics being administered during perforated bowel surgery do not merely having prophylactic effect. It is not intended for tissue sterilization, but to reduce the number of contaminated inoculation during the surgical procedures.4,7
The decision to administer antibiotic prophylaxis should be made by considering their risk and benefits.
One of them includes utilization of the NNIS (National Nosocomial Infections Surveillance) score system, which considers three factors. Antibiotic prophylaxis should be administered when the NNIS score is greater or equals to one.2 The first factor is classification of the operation based on wound surgery as shown on Table 2. Class I (clean) and Class II (clean-contaminated) are scored as zero; while Class III (contaminated) and Class IV (dirty) have one score. The second factor is physical status of the surgical patients according to ASA (American Association of Anesthesiologist) as seen on Table 3. The ASA physical status score of 1 and 2 are given score of zero; while ASA score of 3, 4, and 5 have one score. The third factor is duration of operation according to the NNIS survey, which could be seen on Table 4. Score 1 is assigned when the duration of operation is more than 75%.
Antibiotic prophylaxis has been proven to be effective in reducing the incidence of surgical site infection in contaminated and dirty operation;
therefore, it has been routinely performed. Antibiotic prophylaxis is not recommended for clean surgical wound, except for two most often conditions, i.e.
involving the insertion of intravascular prostethic material or a prosthetic joint or for any operation in which surgical site infection would pose catastrophic risk, such as all cardiac operations (including cardiac pacemaker placement), arterial graft placement at extremities and neurosurgical operations.4,7
There are some general principles that should be noticed in administering antibiotic prophylaxis.
The selected prophylaxis antibiotics must have been shown to reduce surgical site infection incidence based on valid clinical trials. The selected antimicrobial prophylaxis agent should be safe, cost-effective and bactericidal with in vitro spectrum that covers the most probable intraoperative contaminants for the operation.
The timing of administration should be appropriate so that the antibiotic concentration is established relatively high in serum and tissue by the initial time of incision.
The antibiotic concentration should be maintained high throughout the operation and until a few hours later after the incision is closed. 4
Table 3. ASA physical status classification Physical Status of
Surgical Patients Description
ASA 1 Healthy patients
ASA 2 Patients with mild systemic illness No limitation in functional ability ASA 3 Patients with severe systemic illness,
which causes limitations in functional ability
ASA 4 Patients with severe systemic illness and threatening to life
ASA 5 Moribund patients, both with or without surgery
Table 4. Duration of operation according to NNIS Survey Type of Operation Duration of Operation
(hours)
Coronary Artery Bypass Graft 5
Bile duct, liver or pancreas surgery 4
Craniotomy 4
Head and neck surgery 4
Colorectal surgery 3
Prosthetic joint surgery 3
Vascular graft 3
Abdominal or vaginal hysterectomy 2
Ventricular shunt 2
Herniorrhaphy 2
Appendectomy 1
Extremities amputation surgery 1
Caesarean section 1
Parenteral cephalosporins are the most commonly used prophylactic antibiotics, which are usually given as intravenous bolus or fast drip within fifteen to sixty minutes prior to surgical procedures. Prophylaxis using vancomycin or gentamicin is given as slow drip for one hour, within one to two hours prior to surgery.7 Mostly, antibiotic prophylaxis is continued up to 24 hours after surgery. In order to determine the type of appropriate antibiotics for prophylaxis, some experts categorize them based on the type of surgery. Type I surgery only involves skin, excluding other tracts of the body;
therefore, the target pathogens are Staphylococcus;
while type II involves both sites and thus the target pathogens include Staphylococcus, negative gram and anaerobic pathogens. The selection of antibiotic prophylaxis is based on the type of operation as seen on Table 5.
The selection of antibiotics may also based on the performed operation. Appropriate antibiotic selection should be adjusted with pathogens that mostly cause the surgical site infection. A summary is presented on Table 6.7
Table 5. Antibiotic prophylaxis of choice based on type of operation8
Type of Operation Choice Alternative Type I
(Example:
cardiothoracic surgery, vascular graft, orthopedic surgery, craniotomy)
Cefazolin, If <80 kg:
1 gram;
>80 kg: 2 gram
Cefuroxime
allergy to penicillin or
high risk of MRSA Vancomycin, 15 mg/
kgBW Type II
(Example: colorectal surgery, hysterectomy, appendectomy)
Cefazolin plus Metronidazole
Cefoxetan, Cefoxitin, or
Ampicillin- sulbactam
Allergy to penicillin Levofloxacin plus Metronidazole
Metronidazole plus Gentamicin or Quinolone
CONCLUSION
Surgical site infection is increasing with the greater number of surgical procedures and could be prevented. Prevention may include measures of a/
Table 6. Prophylaxis based on type of operation and pathogens7
Operation Most often pathogens Prophylaxis Alternative
Shunts of central nervous system (CNS), craniotomy, open CNS trauma
S. epidermidis
S. Aureus Non- MRSA/ MRSE
Ceftriaxone 2x1g Suspected MRSA/ MRSE Vancomycin 1x1g (iv)
Cefotaxime 1x2g or Ceftizoxime 1x2g
Minocycline 1x200mg or Linezolid 1x600mg (IV) Thoracic surgery (non-cardiac) S. aureus (MSSA) Ceftriaxone 1x2g or Cefazolin
1x2g Cefotaxime 1x2g or Ceftizoxime
1x2g Heart prosthetic replacement
surgery S. Epidermidis (MSSE/ MRSE) Vancomycin 1x1g
Plus Linezolid 1x600mg (IV)
Plus
S. Aureus (MSSA/ MRSA) Gentamicin 1x240mg Gentamicin 1x240mg
CABG S. Aureus (MSSA) Ceftriaxone 1x2g or
Cefazoline 1x2g Cefotaxime 1x2g or Ceftizoxime 1x2g
Biliary Surgery E. coli Ampicillin 1x1g plus or one of
the following:
Klebsiella Ceftriaxone 1x1g or Meropenem 1x2 g or
Enterococci Cefoperazone 1x1g or
Cefazolin 1x1g Ampicillin/sulbactam 1x3 g or Quinolone 1 dose
Liver Surgery E. coli Ampicillin/sulbactam 1x3g or Meropenem 1x2g or
Klebsiella Piperacillin-tazobactam 1x4.5g Moxifloxacin 1x400mg Enterococci
B. fragilis Gastric,proximal intestinal
surgery S. Aureus Ceftriaxone 1x2g or Cefotaxime 1x2g or Ceftizoxime
1x2g Streptococci group A Cefazolin 1x1g
Operation Most Often Pathogens Prophylaxis Alternative Distal intestinal and colonic
surgery E. coli Ceftriaxone 1x2g plus Metronidazole 1x1g plus one of
the following:
Klebsiella Metronidazole 1x1g Moxifloxacin 1x400mg
B. fragilis or Levofloxacin 1x500mg or
Gentamicin 1x240mg Pelvis (Obs-gyn) surgery Gram negative aerobic bacilli
Anareobic streptococci Ceftriaxone 1x2g plus Cefotetan 1x2g or Cefoxitin 1x2g or
B. fragilis Metronidazole 1x1g Ceftizoxime 1x2 g
Orthopedic implant surgery
(total hip/ knee replacement) S. Epidermidis Non- MRSA/MRSE
Cefazolin 1x2g Ceftriaxone 1x2g
Vancomycin 1x1g
S. aureus Suspected MRSA/ MRSE
Teicoplanin 2x400mg 3 doses Linezolid 1x600mg (IV)
Plastic surgery Fosfomycine
Ceftizoxime Levofloxacin
Arthroscopy S. Aureus Gram-negative
enteric bacilli Ceftriaxone 1x2g or
Cefazolin 1x1g or Cefotaxime 1x2g or Ceftizoxime 1x2g Open fracture orthopedic
surgery S. Aureus gram-negative
aerobic bacilli Ceftriaxone 1x2g or
Cefazolin 3x2g for 3-7 days Clindamycin 3x600mg Plus Gentamicin 1x240mg or
Amikacin 2x500mg for 3-7 days Urologic implant surgery S. Aureus gram-negative
enteric bacilli Ceftriaxone 1x2g Cefotaxime 1x2g or
Ceftizoxime 1x2 g TURP cystoscopy P. Aeruginosa Piperacillin/tazobactam 1x4.5g Moxifloxacin 1x400mg or
P. Cepacia Ciprofloxacin 1x400mg or Levofloxacin 1x500mg
P. Maltophilia Linezolid 1x600mg IV Quinipristin/dalfopristin 1x7.5mg/
kg E. Faecalis
Enteric gram-negative bacilli VRE (E. faecium)
antisepsis procedures by the health-care personnel, environment of the operating room and adequate pre-operative preparation for the patient. One of them is antibiotic prophylaxis, which has been proven in some clinical trials that it may significantly reduce incidence and morbidity rate of surgical site infection.
There are basic principles of selecting the type, timing and route of administration of antibiotic prophylaxis to maximize the benefits.
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