R7 Antibiotic Prophylaxis

Surgical Antimicrobial Prophylaxis Guidelines

Preoperative Considerations

Antibiotic prophylaxis to prevent endocarditis is ONLY recommended for patients with cardiac conditions associated with the HIGHEST RISK of adverse outcomes from endocarditis (See Box 1) and only for certain procedures (See Box 2).

Box 1: High-Risk Cardiac Conditions

Antibiotic prophylaxis is recommended for patients with:

• Prosthetic heart valve, including mechanic, bioprosthetic, and homograft valves (transcatheter-implanted as well as surgically implanted)
• Prosthetic material used for cardiac valve repair (e.g., annuloplasty rings and chords)
• Previous infective endocarditis
• Cardiac transplantation with the subsequent development of cardiac valvulopathy (consult cardiologist)
• Rheumatic heart disease in all populations
• Congenital heart disease, only if it involves:
  • i) unrepaired cyanotic defects, including palliative shunts and conduits
  • ii) repaired defects with residual defects at or adjacent to the site of a prosthetic patch or device (which inhibit endothelialisation)

Clinical Decision Path:

• If the patient has any of the conditions listed above: Antibiotic prophylaxis for endocarditis MAY BE required (See Box 2).
• If the patient does NOT have any of the conditions listed above: Antibiotic prophylaxis for endocarditis is NOT required.

Box 2: Procedure-Specific Prophylaxis Requirements

Dental Procedures

Prophylaxis Required:

• Procedures involving manipulation of the gingival or periapical tissue or perforation of the oral mucosa, including:
  • Tooth extraction
  • Matrix band placement
  • Subgingival rubber dam and clamp
  • Implant placement
  • Biopsy
  • Removal of soft tissue or bone
  • Subgingival scaling and root planning
  • Replanting avulsed teeth
  • Apicectomy
  • Six-point pocket charting in diseased tissue
  • Root canal treatment before establishment of an apical stop

Appendix 2: Antibiotic Prophylaxis for Prevention of Endocarditis in High Risk Patients¹

Prophylaxis NOT Required:

• Oral examination
• Infiltration and block local anaesthetic injection through non-infected tissue
• Restorative dentistry
• Supragingival rubber dam clamping and placement of rubber dam
• Intracanal endodontic procedures
• Removal of sutures
• Impressions and construction of dentures
• Orthodontic bracket placement and adjustment of fixed appliances
• Application of gels
• Dental radiography
• Supragingival plaque removal

Respiratory Tract or Ear, Nose & Throat (ENT) Procedures

Prophylaxis Required:

• Tonsillectomy / adenoidectomy
• Any invasive procedure to treat an established infection (e.g., drainage of abscess)

Prophylaxis NOT Required:

• Endotracheal intubation
• Rigid or flexible bronchoscopy with or without incision or biopsy
• Transoesophageal echocardiography

Genitourinary (GU) and Gastrointestinal (GI) Procedures

Prophylaxis Required:

• Any GU procedure in the presence of a GU infection unless already treating enterococci (for elective cystoscopy or urinary tract manipulations, obtain a urine culture and treat any bacteriuria beforehand)
• Any GI procedure in the presence of infection or colonisation unless already treating enterococci
• Sclerotherapy for oesophageal varices

Prophylaxis NOT Required:

• Urethral catheterisation
• Transervical procedures (e.g., uterine dilation and curettage, sterilisation procedures, insertion or removal of intrauterine device)
• Obstetric procedures including surgical termination of pregnancy
• Endoscopy (with or without gastrointestinal biopsy including colonoscopy)

Other Procedures

Prophylaxis Required:

• Procedures involving infected skin, skin structures, or musculoskeletal tissues (e.g., incision and drainage of local abscess, epidural, lung, orbital, perirectal, pyogenic liver)
• Percutaneous endoscopic gastrostomy (PEG) or PEJ

Practice Points

Surgical antibiotic prophylaxis must be administered before surgical incision to achieve effective plasma and tissue concentrations at the time of incision. Administration of any antibiotic after skin incision reduces effectiveness.

Administration Guidelines by Route and Agent

• Oral Antibiotics

  • Amoxicillin or cefalexin: Give 60 minutes prior to the procedure.
  • Clindamycin: Give 60 to 120 minutes prior to the procedure.

• IV Amoxicillin

  • Can be given over 3 to 4 minutes.
  • Should be commenced within 60 minutes prior to the procedure.

• IV Cefazolin

  • Can be given over 5 minutes.
  • Administer no more than 60 minutes before skin incision.

• IV Clindamycin

  • Infusion should be commenced within 120 minutes prior to the procedure.
  • Administer doses of 600mg over at least 20 minutes (maximum rate of 30mg/min).

• IV Vancomycin

  • Adults: 1g over at least 60 minutes; 1.5g over at least 90 minutes.
  • Paediatrics: Infusion should be given over 120 minutes.
  • Timing: Begin 15 to 120 minutes before skin incision to ensure adequate concentration and allow for recognition of infusion-related toxicity before induction. The infusion can be completed after skin incision.

Dosing in Patients with Obesity

• Cefazolin: Consider an increased dose of 3g for adult patients weighing more than 120kg.
• Vancomycin: Consider an increased dose of 1.5g for adult patients weighing more than 80kg.

Repeat Intraoperative Dosing

Timing and Administration of Antibiotics²

A single preoperative dose is sufficient for most procedures; however, repeat intraoperative doses are advisable in the following scenarios:

1. Prolonged Surgery: If the procedure lasts more than 4 hours from the time of the first preoperative dose when using a short-acting agent (e.g., repeat cefazolin after 4 hours).
2. Major Blood Loss: If loss exceeds 1500 mL in adults, following fluid resuscitation.

Note: When calculating the time for a second intraoperative dose, measure the interval from the time of the first preoperative dose, not the surgical incision time.

Recommended Prophylaxis Regimens

Procedure	Recommended Prophylaxis	Penicillin / Cephalosporin Allergy
Dental procedures	Amoxicillin 2g orally (child: 50mg/kg up to 2g) 60 mins prior OR if oral not possible: Amoxicillin 2g IV (child: 50mg/kg up to 2g)	Moderate risk allergy: Cefalexin 2g orally (child: 50mg/kg up to 2g) 60 mins prior OR if oral not possible: Cefazolin 2g IV (child: 30mg/kg up to 2g)
Tonsillectomy / Adenoidectomy / All other procedures	Amoxicillin 2g IV (child: 50mg/kg up to 2g) OR Vancomycin 1g IV infusion (1.5g for adults >80kg) (child: 30mg/kg up to 1.5g)	High risk allergy: Clindamycin 600mg orally (child: 20mg/kg up to 600mg) 60-120 mins prior OR if oral not possible: Clindamycin 600mg IV infusion (child: 20mg/kg up to 600mg)

Allergy and Clinical Notes:

• Moderate risk penicillin allergy: History suggestive of moderate risk (e.g., delayed rash which is NOT urticarial or DRESS/SJS/TEN).
• High risk penicillin/cephalosporin allergy: History suggestive of high risk (e.g., anaphylaxis, angioedema, bronchospasm, urticaria, DRESS/SJS/TEN).
• Vancomycin-resistant enterococci: For patients colonised or infected, seek advice from Infectious Diseases (ID) for an appropriate regimen.

Definitions and Acronyms

• AMS: Antimicrobial Stewardship
• DRESS: Drug rash with eosinophilia and systemic symptoms
• ID: Infectious Diseases
• IV: Intravenous
• PO: Per oral
• SJS / TEN: Stevens-Johnson syndrome / Toxic epidermal necrolysis

References

• Antibiotic Expert Groups (2019). Therapeutic Guidelines: Antibiotic. Version 16.
• Australian Injectable Drugs Handbook (2020) 8th ed.
• Bakhsh, A, et al (2020). “A review of guidelines for antibiotic prophylaxis before invasive dental treatments.” Applied Sciences 11,311: 1-11.
• Glenny AM, Oliver R, et al (2013). “Antibiotics for the prophylaxis of bacterial endocarditis in dentistry”. Cochrane Database of Systematic Reviews.
• Habib G, et al (2015). “ESC Guidelines for the management of infective endocarditis”. Eur Heart J. 36:3075-128.
• Nishimura, RA., et al (2017). “AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease”. J Am Coll Cardiol 70 (2): 252-89.
• Sexton DJ., Chu VH (2020). “Antimicrobial prophylaxis for bacterial endocarditis”. UpToDate.
• Wilson, W., et al (2007). “Prevention of infective endocarditis: guidelines from the American Heart Association”. Circulation 116 (15): 1736-54.
• RHD Australia (2020). The 2020 Australian guideline for prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease (3rd ed).

Footnotes

1. Original PDF page 1: R7 Surgical Antibiotic Prophylaxis, p.1 ↩

2. Original PDF page 2: R7 Surgical Antibiotic Prophylaxis, p.2 ↩