Prophylactic Antibiotic Therapy Guideline

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Date: 07/2026 | Location: MH Katy

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Extremities
Antibiotics for open extremity fractures to be administered within 60 minutes of patient arrival.

Type 1	Antibiotic	Cefazolin 2g IV q8 Penicillin allergy: clindamycin 900 mg IV q8 hours
	Duration	24 hours
Type 2	Antibiotic	Cefazolin 2g IV q8 Penicillin allergy: clindamycin 900 mg IV q8 hours
	Duration	24 hours
Type 3	Antibiotic	Ceftriaxone 2g IV q24 hours and vancomycin* 15 mg/kg IV q12 hours Penicillin allergy: same.
	Duration	24 hours
	*Note: pharmacy will automatically dose vancomycin per protocol unless we write in the comments to not

Face and Scalp

Closed facial fractures	Antibiotic	No prophylactic antibiotics
	Duration
Open facial fractures	Antibiotic	Ampicillin-sulbactam 3g IV q6 hours Penicillin allergy: clindamycin 600 mg IV q8
	Duration	24 hours after admission; can resume 24 hours after fixation
	Bacteria of concern: staphylococcus aureus and epidermidis, streptococcus, Enterobacter, pseudomonas, E. coli

Central Nervous System

Pneumocephalus	Antibiotic	No prophylactic antibiotics
	Duration
CSF leak	Antibiotic	No prophylactic antibiotics
	Duration
Penetrating brain or spine injury	Antibiotic	Nafcillin 2g IV q4 hours and ceftriaxone 2g IV q12 hours (add metronidazole if trans colonic trajectory)
	Duration	72 hours after admission or 24 hours after fixation, whichever comes first
	Bacteria of concern: staphylococcus aureus, staphylococcus epidermidis
Open skull fracture	Antibiotic	Nafcillin 2g IV q4 hours and ceftriaxone 2g IV q12 hours
	Duration	72 hours after admission or 24 hours after fixation, whichever comes first
	Bacteria of concern: staphylococcus aureus, staphylococcus epidermidis

Surgical Prophylaxis

1. Antibiotics are to be given within 60 minutes of incision
2. Re-dosing in operating room is based upon half-life of antibiotic and blood loss (every 1,500 mL of blood loss)
3. Prophylaxis should not be continued more than 24 hours after surgery

Neck	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg)
	Re-dosing	Every 4 hours and every 1,500 mL blood loss
Cardiac/thoracic	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg)
	Duration	Every 4 hours and every 1,500 mL blood loss
Abdomen (no colon)	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg)
	Duration	Every 4 hours and every 1,500 mL blood loss
Abdomen (with colon)	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg) Metronidazole 500 mg IV once
	Duration	Cefazolin: every 4 hours and every 1,500 mL blood loss Metronidazole: every 8 hours and every 1,500 mL blood loss
Vascular	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg)
	Duration	Every 4 hours and every 1,500 mL blood loss
Skin and soft tissue	Antibiotic	Cefazolin 2 g IV once (3 g IV if ≥120 kg)
	Duration	Every 4 hours and every 1,500 mL blood loss

Post Operative Surgical Prophylaxis

• Limit antibiotic treatment to 24 hours for the following:
  • Traumatic bowel perforations controlled within 12 hours
  • Gastroduodenal perforations controlled within 24 hours
  • Acute of gangrenous appendicitis without perforation
  • Acute or gangrenous cholecystitis without perforation
  • Ischemic, non-perforated bowel
• Limit antibiotic treatment to 4 days (96 hours) following definitive source control in the setting of complex intra-abdominal infection with the following exceptions:
  • There is clinical evidence of treatment failure and radiographic evidence of persistent inflammation/infection.
  • The patient has clinical evidence of treatment failure and cannot undergo further source control.
• Limit antibiotic treatment to 5-7 days in patients who have not had definitive source control of intra-abdominal infection.