Commonly Used OR Antibiotics

Giving IV antibiotics prior to surgery is one of the more important actions we can take as anesthesia providers to prevent surgical site infection. Early on in your education it may seem like every patient gets 2 grams of Ancef, but this is certainly not always the case. This tutorial is designed to help you understand and know how much of what antibiotic to give in different scenarios. Pretty much everything listed here is based directly off of SCIP (Surgical Care Improvement Project) guidelines, which is considered the national standard. Some institutions and surgeons, however, have certain antibiotics, doses, or dosing schedules they prefer (usually still within guidelines), so always be sure to double check with the surgeon prior to administration. 

Below you will find tables showing which antibiotics are acceptable to use in different surgeries, their doses, and how often they should be re-dosed.

Anti-microbial agent	Adult Dose	Pediatric Dose	Redosing Time
Ampicillin	2g	50mg/kg	2 hours
Cefazolin (Ancef)	1g,2g, 3g (over 120kg)	30mg/kg	4 hours
Cefuroxime	1.5g	50mg/kg	4 hours
Cefotaxime	1g	50mg/kg	3 hours
Cefoxitin	2g	40mg/kg	2 hours
Ceftriaxone	2g	50-75mg/kg	NA
Ciprofloxacin	400mg	10mg/kg	NA
Clindamycin	600mg, 900mg	10mg/kg	6 hours
Fluconazole	400mg	6mg/kg	NA
Gentamycin	5mg/kg	2.5mg/kg	NA
Levofloxacin	500mg	10mg/kg	NA
Metronidazole (Flagyl)	500mg	15mg/kg	NA
Vancomycin	15mg/kg (usually in 0.5g incriments)	15mg/kg	12 hours

Type of Surgery	Prefered Antimicrobial	If Beta-Lactam Allergy
Cardiac & Vascular	Cefazolin	Clindamycin or Vancomycin
Colon	Cefoxitin	Flagyl or Cipro
Gen. Surgery	Cefazolin	Clindamycin or Vancomycin
Gynecological Procedures	Cefoxitin	Flagyl & Gent; or Flagly & Cipro
Neurosurgery	Cefazolin	Clindamycin or Vancomycin
Orthopedic	Cefazolin	Clindamycin or Vancomycin

All antibiotics listed, with the exception of Vancomycin (2 hour window), should be administered within a 1 hour window prior to surgical incision. Within half an hour is considered even better. If the dose is prior to the one hour window, discuss with your surgeon and attending about giving another dose.

Try and commit the more commonly used antibiotics to memory: Ancef, Vancomycin, Clindamycin

    

A few good useful pieces of information to know about antibiotics:

1. Antibiotics are one of the more common medications that patients have immune-mediated reactions to – rash, pruritis, bronchospasm, anaphylaxis.
2. Certain antibiotics, most notably Vancomycin, can cause non-immune mediated histamine releases, triggering symptoms that look very similar to an anaphylactic reaction. To avoid this with Vancomycin, put in a 100cc or 250cc bag of NS and run in over an hour. You will come across a number of antibiotics in our career, many that you are unfamiliar with. If you are unsure whether or not to run it in slowly, check the vial or contact the pharmacy.
3. You will often come across surgeons and anesthesiologist that like to avoid Cephalosporins (such as Ancef) in patients with Penicillin allergies because concerns of cross reactivity. The truth is, there is a very low incidence of patients having an anaphylactic reaction to cephalosporins with a penicillin allergy. However, it is still reasonable to avoid in these situations.   
4. Some antibiotics can cause ototoxicity (issues with your hearing) – particularly Vancomycin and Gentamycin.
5. Some antibiotics can be nephro-toxic – ie. Gentamycin.