Prophylactic antibiotic timing and dosage Dr. Sanjeev Singh AIMS, Kochi
Meaning - Webster Medical Definition of prophylaxis plural pro phy lax es \-ˈlak-ˌsēz\play : measures designed to preserve health and prevent the spread of disease : protective or preventive treatment <prophylaxis against viral diseases> <a paste containing fluorine for dental prophylaxis>
Definition Antibiotic prophylaxis refers to the prevention of infection complications using antimicrobial therapy Surgical antibiotic prophylaxis is defined as the use of antibiotics to prevent infections at the surgical site.
Indications Immune compromised Cardiac valves, prosthetics in body Visit to another country Surgery SIGN 104 Antibiotic prophylaxis in surgery. A national clinical guideline. July 2008
A single antibiotic dose, given immediately before the start of surgery, may be just as effective in preventing infection, while reducing the risk of drug side effects http://www.surgeryencyclopedia.com/pa-st/ Prophylaxis-Antibiotic.html#ixzz407iM1Dr3
Classification of operative wounds and risk of infection Classification Criteria Risk (%) Clean Clean-contaminated Contaminated Elective, not emergency, nontraumatic, primarily closed; no acute inflammation; no break in technique; respiratory, gastrointestinal, biliary and genitourinary tracts not entered Urgent or emergency case that is otherwise clean; elective opening of respiratory, gastrointestinal, biliary or genitourinary tract with minimal spillage (e.g., appendectomy) not encountering infected urine or bile; minor technique break Nonpurulent inflammation; gross spillage from gastrointestinal tract; entry into biliary or genitourinary tract in the presence of infected bile or urine; major break in technique; penetrating trauma < 4 hours old; chronic open wounds to be grafted or covered < 2 <10 Approx. 20 Dirty Purulent inflammation(e.g., abscess); preoperative perforation of respiratory, gastrointestinal, biliary or genitourinary tract; penetratinbg trauma > 4 hours old Approx. 40 Cruze PJ, Ford. The epidemiology of wound infection. A 10-year prospective study of 62,939 wounds. Surg Clin North Am. 1980 Feb;60(1):27-40.
Common surgical pathogens clean procedures - skin flora, including S. aureus and coagulase-negative staphylococci clean-contaminated procedures (abdominal procedures and heart, kidney, and liver transplantations) - gram-negative rods and enterococci in addition to skin flora ASHP Report. Am J Health-Syst Pharm Vol 70 Feb 1, 2013,204-5
The use of antimicrobial agents for dirty procedures or established infections is classified as treatment of presumed infection, not prophylaxis
Choice of antibiotics should be made according to data on pharmacology, microbiology, clinical experience and economy Antibiotics should be chosen with kinetics that will ensure adequate serum and tissue levels throughout the risk period.
Ideal antibiotic good tolerability Low toxicity High concentration at all sites systemic vs local Long acting Cephalosporin
MIC Minimum Inhibitory Concentration (MIC) is the lowest concentration of an antimicrobial that will inhibit the visible growth of a microorganism after overnight incubation.
Vancomycin Routine use of vancomycin prophylaxis is not recommended for any procedure Included in the regimen of choice when a cluster of MRSA cases (e.g., mediastinitis after cardiac procedures) or methicillin resistant coagulase-negative staphylococci SSIs have been detected at an institution. Scottish Intercollegiate Guidelines Network. Antibiotic prophylaxis in surgery. www.sign.ac.uk/pdf/sign104.pdf (accessed 2009 Jul 30).
Advantage of long acting antibiotic A single dose covers the whole perioperative risk period - even if the operation is delayed or long-lasting Repeat administrations for prophylaxis are not necessary, so that additional doses are less likely to be forgotten Less risk of development of resistance and less side effects Increased compliance and reduced errors of administration Possibly better-effectiveness (less material and labor cost, less septic perioperative complications)
Factors that affect physicians compliance Cultural factors Educational background Training Nurse and pharmacist influences, Medication supply Logistics Ali A. Al-Dabbagh, and Mazin A. Hajy. How Good is Compliance with Surgical Antibiotic Prophylaxis Guidelines in Erbil/ Iraq?. 2nd International Conference on Medical, Biological and Pharmaceutical Sciences (ICMBPS'2013) June 17-18, 2013 London (UK)
Cleveland Clinic Guidelines for Antimicrobial Usage 2012-2013
American Society of Health-System Pharmacists. 2013
Timing The antibiotic should be administered ideally 30 minutes before incision in order to achieve relevant tissue concentration. In operations lasting longer than three hours a second dosage is recommended. There is no evidence to support a prolongation of antibiotic administration to 24 or 48 hours in most instances. Single dose is cheaper and does not increase the risk of the developement of bacterial resistance Classen D C, Evans R S, Pestotnik S L, Horn S D, Menlove R L, Burke J P. The timing of prophylactic administration of antibiotics and the risk of surgical-wound infection. N Engl J Med. 1992;326:281 286.
For surgical procedures, intravenous prophylactic antibiotics should be given within 60 minutes before the skin is incised and as close to time of incision as practically possible. vancomycin should be given by intravenous infusion starting 90 minutes prior to skin incision. Scottish Inter collegiate guidance network (SIGN). Antibiotic prophylaxis in Surgery. Edinburg.2008, updated 2014
Fluoroquinolones and Vancomycin, require administration over one to two hours therefore, the administration of these agents should begin within 120 minutes before surgical incision. ASHP Therapeutic guidelines
NICE and the Infectious Diseases Society of America (IDSA) recommends that -for Caesarean section, antibiotic prophylaxis to reduce maternal infectious complications can be given pre-incision or after cord clamping National Collaborating Centre for Women s and Children s Health. Caesarean section. London: NICE; 2011. [cited 01/05/2013]. Bratzler DW, Dellinger EP, olsen KM, Perl TM, Auwaerter PG, Bolon MK, et al. Clinical practice guidelines for antimicrobial prophylaxis in surgery. Am J Health Syst Pharm 2013;70(3):195-283.
Dosage A single standard therapeutic dose of antibiotic is sufficient for prophylaxis under most circumstances
Duration A single dose of antibiotic with a long enough half-life to achieve activity throughout the operation is recommended. up to 24 hours of antibiotic prophylaxis should be considered for arthroplasty.
Additional dosage An additional intraoperative dosage of antibiotic is recommended for cardiac surgery longer than four hours when using an antibiotic with pharmacokinetics equivalent to cefazolin. Zanetti G, Giardina R, Platt R. Intraoperative redosing of cefazolin and risk for surgical site infection in cardiac surgery. Emerging Infectious Diseases 2001;7(5):828-31
In the event of major intraoperative blood loss in adults (>1,500 ml) or (children 25ml/kg) additional dosage of prophylactic antibiotic should be considered after fluid replacement.
How many days If prophylactic antibiotic given more than 24 hours it is no longer a prophylaxis but therapeutic schedule