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Antimicrobial Stewardship (AMS)

Resources to help you ensure the safe and effective use of antimicrobials in NSHA patients.

Surgical Site Infection Prophylaxis

Principles for antimicrobial prophylaxis of surgical site infections (SSIs)

  1. Patients having surgery for which prophylactic antibiotics are recommended should receive them as a standard of care.
  2. The choice of surgical prophylaxis should cover pathogens that commonly cause SSI for that procedure. 
    • It is not necessary to cover or eradicate all possible microorganisms in the surgical field.
  3. Patients labelled with an antibiotic allergy should be asked what antibiotic caused the reaction, how was it administered, what was the reaction, and when did the reaction occur. 
  4. Antibiotics should be dosed to optimize tissue concentrations.
  5. Antibiotics should be administered within 60 minutes before surgical incision.
    • Vancomycin and aminoglycosides require longer infusion times and should be timed to ensure completion within 60 minutes prior to incision.
  6. Antibiotics should be re-dosed intra-operatively if the duration of the procedure exceeds 2 half-lives of the antibiotic.
    • Should also re-dose if there is excessive blood loss (more than 1.5L in adults) for all antibiotics except vancomycin.
  7. Antibiotics should not be given postoperatively unless there is an indication other than prophylaxis (i.e., treatment of contamination or infection).
    • Postoperative prophylaxis which does not exceed 24 hours may be considered in cardiovascular, orthopedic, vascular and orthognathic surgery.
    • Patients who have indwelling drains or intravascular catheters do not require extension of prophylaxis duration.
    • A 2019 survey of surgical prophylaxis in NS Health found that surgical prophylaxis was given longer than 24h in 39% of patients (national comparison 29%).

Last reviewed January 2024

Dosing and re-dosing recommendations for antimicrobials commonly used for surgical prophylaxis

  • Cefazolin is the preferred agent for surgical prophylaxis 
    • Cefazolin is safe in most patients with a penicillin allergy
      • Except for a history of severe delayed skin reaction/organ dysfunction (e.g., Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms) to any beta-lactam antimicrobial OR a history of anaphylaxis to cefazolin
    • Cefazolin can be administered quickly and has a favorable side-effect profile
    • Cefazolin is effective for pathogens that commonly cause SSIs

 

  • Clindamycin was excluded from these recommendations because pathogens that cause SSI are often resistant to clindamycin; and clindamycin is not as safe because even one dose can be complicated by C. difficile infection.
    • If emergent surgery precludes the infusion time for vancomycin, clindamycin may be used instead when there is a contraindication to cefazolin

Antimicrobial

 Adult dose Pediatric dose*
(max dose should not exceed
the recommended adult dose)		 Intra-operative 
re-dosing 
(from time of administration of pre-op dose)
Cefazolin 2 g
Consider 3g if weight above 120 kg

30 mg/kg/dose
Max 2000mg/dose

 Every 4 h (Max 6 g/24h)
Aminoglycoside:
Tobramycin		 2.5 mg/kg
(Round to nearest 20 mg)		 2.5 mg/kg/dose 
Max 120mg/dose
 		 At 6h x 1 (if CrCl greater than or equal to 60 ml/min)
Pediatrics: none required
Metronidazole 500 mg 15 mg/kg/dose
Max 500mg/dose 		 At 12 hrs x 1 
Pediatrics: see IWK Firstline App
Vancomycin

15 mg/kg round nearest 250 mg
(Max 2000 mg/dose)

Administer:

  • 1g or less over 60 min,
  • 1g-1.5g over 90 min,
  • More than 1.5 g over 120 min

15 mg/kg/dose
Max 1000mg/dose

At 12h x 1 (if CrCl greater than or equal to 60 ml/min)

Pediatrics: see IWK Firstline App
 

*For more detailed pediatric recommendations, please refer to the IWK Firstline App

Last reviewed January 2024

Systemic surgical prophylaxis recommendations:

Note: for detailed pediatric recommendations, please refer to the IWK Spectrum App

 
Type of Surgery Recommended Antimicrobial(s)

Alternative Antimicrobial(s) if anaphylaxis to cefazolin or severe delayed reaction to any beta-lactam such as SJS/TEN, DRESS, AGEP
Cardiac

Coronary artery bypass (CABG),
valve replacement (+/- CABG), 
other cardiac procedures

 cefazolin vancomycin
Ventricular assist devices
Device insertion (e.g., pacemaker)
 		 cefazolin vancomycin
Cardiac catheterization
Transesophageal echocardiogram		 none none
General
Gastroduodenal/esophageal cefazolin vancomycin + 
aminoglycoside
PEG insertion  cefazolin vancomycin
Biliary tract - laparoscopic procedure – Low risk none none

Biliary tract - laparoscopic procedure – High risk 
Non-elective, inserting prosthetic device, diabetes, duration greater than 120min, risk of intraoperative gallbladder rupture/conversion to open, age of 70 years or more, ASA greater than or equal to 3, reintervention within a month, acute cholecystitis, jaundice, pregnancy, immunosuppression

 cefazolin vancomycin + 
aminoglycoside
Biliary tract - open procedure cefazolin vancomycin + 
aminoglycoside
Colorectal, small bowel, appendectomy 
Pancreaticoduodenectomy		 cefazolin + 
metronidazole		 vancomycin +     
aminoglycoside + 
metronidazole
Hernia repair - Hernioplasty, herniorrhaphy cefazolin vancomycin
Low risk anorectal procedures: hemorrhoidectomy, fistulotomy, sphincterotomy none none
Thoracic
Non-cardiac procedures
(e.g., lobectomy, pneumonectomy, lung resection, and thoracotomy) 
Video-assisted thoracoscopic surgery		 cefazolin vancomycin
Thoracentesis or chest tube insertion for non-traumatic indications (e.g., spontaneous pneumothorax) none none
Head and Neck
Clean: no incision through oral/nasal/pharyngeal mucosa (e.g., parotidectomy, thyroidectomy, and submandibular gland excision) none none
Clean with placement of prosthetic material (excludes tympanostomy tubes that do not require prophylaxis) cefazolin vancomycin
Clean-contaminated (incision through oral/pharyngeal mucosa): cancer surgery and other clean-contaminated procedures with the exception of tonsillectomy and functional endoscopic sinus procedures cefazolin + 
metronidazole		 vancomycin + 
metronidazole
Neurosurgery
Elective craniotomy, stereotactic brain biopsy, cerebrospinal fluid-shunting procedures, ICP monitor, external ventricular drain, and implantation of intrathecal pumps cefazolin vancomycin
Orthopedic
Arthroscopy without graft implantation none none
Spinal procedures with and without instrumentation, hip fracture repair, Implantation of internal fixation devices (e.g., nails, screws, plates, wires), and total joint replacement cefazolin vancomycin
Urologic
In addition to the prophylaxis recommendations below, obtain urine culture prior to stone removal or invasive procedures involving mucosal bleeding/trauma. If bacteria are found in the culture, treat based on sensitivities prior to performing the procedure.
Cystoscopy/Shock-wave lithotripsy 
  • No risk factors, urine culture negative
 none

Cystoscopy/Shockwave lithotripsy:

Risk factors:

  • Advanced age, immunocompromised, anatomic abnormalities, poor nutrition, diabetes mellitus, smoking, prolonged catheters
  • Manipulation (prostatectomy, biopsy, foreign body removal, urethral dilation, stent placement/removal, ureteroscopy)

If no hospitalization in last year, recent antibiotic use from the class, or other risks for resistance:

  • cefazolin 2g IV x 1 dose or
  • ciprofloxacin 500 mg PO or 
  • Sulfamethoxazole-trimethoprim (SMX-TMP) 1 DS tablet (160/800 mg) PO
  • give 1-2 hours pre-procedure

If risk of Gram-negative bacteria resistance (including prolonged hospitalization, infection or colonization with resistant bacteria, or recent fluoroquinolone/TMP-SMX use) select one of the following instead:

  • Ceftriaxone 1g IM/IV 1 hour pre-procedure

or

  • Tobramycin 1.5 mg/kg IV/IM (round to nearest 20 mg; maximum IM dose 120 mg) 1 hour pre-procedure
Transrectal prostate biopsy

Give 1-2 hours pre-procedure:

  • ciprofloxacin 500 mg PO or 
  • Sulfamethoxazole-trimethoprim (SMX-TMP) 1 DS tablet (160/800 mg) PO

If risk of Gram-negative bacteria resistance:

  • Prior episode of post biopsy sepsis
  • Health care worker who works directly with patients 
  • Fluoroquinolone use 6 months prior to biopsy 
  • Recent international travel (particularly Asia) in last 90 days
  • Diabetes 
  • Immunosuppression due to medications, prior transplant or medical conditions 
  • Recent hospital admission in last 90 days 
  • Prior infection with fluoroquinolone resistant bacteria

add 

  • Ceftriaxone 1 g IM/IV 

or

  • Tobramycin 1.5 mg/kg IM or IV (rounded to nearest 20 mg; max dose of 120 mg for IM)
Percutaneous renal surgery cefazolin vancomycin
Open or Laparoscopic:
without entry into bowel/vagina		 cefazolin vancomycin + 
tobramycin
Open or Laparoscopic:
involving manipulation of bowel/vagina
 		 cefazolin + 
metronidazole		 vancomycin + 
aminoglycoside + 
metronidazole
Vascular
Arterial surgery
Graft placement or repair		 cefazolin vancomycin
Plastics
Clean without risk factors none none
Clean - high risk 
  • prosthetic material, skin irradiation, traumatic/crush hand injuries, flap reconstruction, panniculectomy, injuries requiring amputation/reconstructive limb surgery, injuries involving bone, joint, tendon (except open flexor tendon injuries) or nerve
Clean-contaminated
 		 cefazolin vancomycin
Breast surgery cefazolin vancomycin
Obstetrical/Gynecological
Caesarean section cefazolin vancomycin + 
aminoglycoside
Hysterectomy cefazolin +/- 
metronidazole		 vancomycin + 
aminoglycoside +/- 
metronidazole
Laparoscopic procedures that involve no direct access from the abdominal cavity to the uterine cavity or vagina none none

Last reviewed January 2024

1. University of Toronto Best Practice in Surgery Program.http://bestpracticeinsurgery.ca/wp-content/uploads/2017/11/SSI-BPS-CPG-Nov20.pdf

2. World Health Organization. Global Guidelines for the Prevention of Surgical Site Infection.https://www.who.int/gpsc/ssi-prevention-guidelines/en/

Last reviewed January 2024

Traumatic Open Fracture Prophylaxis

  • An open fracture is any fracture accompanied by a break in skin that communicates with the fracture or associated hematoma.
  • The Gustilo-Anderson Classification (Table 1) of open fractures is the most widely used classification system for open fractures and can be used to guide antibiotic prophylaxis.
    • In general, risk of infection and incidence of limb loss correlates with the Gustilo-Anderson classification.
  • Special consideration should also be given to potential contaminants in the environment associated with the injury (Table 2) for which additional antimicrobial coverage may be warranted (Table 3).

Last reviewed November 2024

Table 1. Gustilo-Anderson Classification of Open Fractures

Type Details
I Open fracture with a wound less than 1 cm long, low energy, without gross contamination
II Open fracture with a wound 1–10 cm long, low energy, without gross contamination or
extensive soft-tissue damage, flaps, or avulsions
III-A Open fracture with a wound greater than 10 cm with adequate soft-tissue coverage, or any open fracture due to high-energy trauma or with gross contamination, regardless of the size of the wound
III-B Open fracture with extensive soft-tissue injury or loss, with periosteal stripping and boneexposure that requires soft-tissue coverage in the form of muscle rotation or transfer
III-C Open fracture associated with arterial injury requiring repair

Last reviewed November 2024

Table 2. Fracture Scenario and Corresponding Suspected Microorganisms

Scenario Microorganisms
Type I or Type II fracture Gram-positive cocci (S. epidermidis, S. aureus, β-hemolytic streptococci) +/- Gram-negative bacilli
Type III-A, III-B, or III-C fracture Gram-positive cocci (S. epidermidis, S. aureus, β-hemolytic streptococci) + Gram-negative bacilli

Known MRSA colonization, previous MRSA infection, known injection drug use

 MRSA
Additional contamination considerations
Soil/stool/sewage water or farm related injury Clostridium species
Freshwater Aeromonas hydrophila, Pseudomonas and Plesiomonas species, Erysipelothrix rhusiopathiae, Mycobacterium marinum, and other microbes
Saltwater Vibrio species

Last reviewed November 2024

  • The American College of Surgeons Trauma Quality Improvement Plan recommends initiation of antibiotics within 1 hour of presentation to reduce the risk of infection.

Last reviewed November 2024

Table 3. Fracture Scenario and Corresponding Empiric Treatment Options

Fracture Type  Type I, Type II Type IIIA, Type IIIB, Type IIIC
Grade-guided
prophylaxis
  • Cefazolin 2 g IV Q8H
    • If 120 kg or greater: Cefazolin 3 g IV x 1 then 2 g IV q8h
  • Alternative if anaphylaxis to cefazolin or history of severe delayed skin reaction/organ dysfunction to any beta-lactam antimicrobial:
    • Vancomycin 15 mg/kg IV q12h
  • Piperacillin- Tazobactam 4.5 g IV q6h

 

  • Alternative if anaphylaxis to penicillin or history of severe delayed skin reaction/organ dysfunction to any beta-lactam antimicrobial:
    • Cefazolin 2 g IV Q8H + Tobramycin* 5 mg/kg IV q24h
      • 120 kg or greater: Cefazolin 3 g IV x 1 then 2 g IV q8h + Tobramycin* 5 mg/kg IV q24h
Risk factors for MRSA Add vancomycin 15 mg/kg IV q12h (or if cefazolin used for grade-guided prophylaxis, replace cefazolin with vancomycin)
Additional Prophylaxis for Contamination
Soil/stool/sewage water or farmrelated injuries

Add Metronidazole 500 mg po/IV q8h

If on Piperacillin-Tazobactam: No addition needed
Freshwater

Add Ciprofloxacin 750 mg PO q12h or Ciprofloxacin 400 mg IV q8h

 

If on Piperacillin-Tazobactam: No addition needed

If on Cefazolin + Tobramycin: No addition needed
Saltwater

Use Piperacillin-Tazobactam 4.5 g IV q6h and Doxycycline 100 mg PO BID; recommended for all open fractures with saltwater contamination

 

If anaphylaxis to penicillin or history of severe delayed skin reaction/organ dysfunction to any beta-lactam antimicrobial:
Cefazolin + Tobramycin as above and Doxycycline 100 mg PO BID

*(If actual body weight more than 30 % above ideal body weight, use dosing body weight for tobramycin – see Firstline for details)

Last reviewed November 2024

  • Discontinue prophylactic antimicrobials 24 hours following soft tissue closure.

Last reviewed November 2024

1.  Carsenti-Etesse H, et al. Epidemiology of bacterial infection during management of open leg fractures. Eur J ClinMicrobiol Infect Dis. 1999;18(5):315Y323.

2. Garner MR, et al. Antibiotic Prophylaxis in Open Fractures: Evidence, Evolving Issues, and Recommendations. J Am Acad Orthop Surg. 2020 Apr 15;28(8):309-315. doi: 10.5435/JAAOS-D-18-00193. PMID: 31851021.

3. Goldman AH, et al. J Am Acad Orthop Surg. 2023 Jan 1;31(1):e1-e8. doi: 10.5435/JAAOS-D-22-00792. Epub 2022 Nov 3. PMID: 36548150.

4. Gustilo RB, et al. Prevention of infection in the treatment of one thousand and twenty-five open fractures of long bones: Retrospective and prospective analyses. J Bone Joint Surg Am 1976;58:453-458.

5. Gustilo RB, et al. Problems in the management of type III (severe) open fractures: A new classification of type III open fractures. J Trauma 1984;24:742-746.

6. Sunnybrook “Antibiotic prophylaxis for open fractures’ Prophylaxis Guidelines - Antimicrobial Stewardship - Sunnybrook Hospital

7. EAST Open Fractures, Prophylactic Antibiotic Use in — Update Open Fractures, Prophylactic Antibiotic Use in — Update - Practice Management Guideline (east.org)

8. Robinson D, et al. Microbiologic flora contaminating open fractures: its significance in the choice of primary antibiotic agents and the likelihood of deep wound infection. J Orthop Trauma. 1989;3: 283–286.

9. Rodriguez L, et al. Evidence-based protocol for prophylactic antibiotics in open fractures: Improved antibiotic stewardship with no increase in infection rates. Journal of Trauma and Acute Care Surgery 77(3):p 400-408, September 2014.

10. Standardized Antibiotic Prophylaxis Protocol for Acute Open Fractures in the Emergency Department and on the Orthopaedic Trauma Service - Microsoft Word - Open Frx Abx Protocol -for distribution V2.1.docx (stanford.edu)

11. Suzuki T, et al. Type III Gustilo–Anderson open fracture does not justify routine prophylactic Gramnegative antibiotic coverage. Sci Rep 13, 7085 (2023). https://doi.org/10.1038/s41598-023-34142-7

12. University of Nebraska Medical Center “Antibiotic Prophylaxis in Open Fractures” surgical-antibioticprophylaxis-in-open-fractures-guideline.pdf (unmc.edu)

Last reviewed November 2024