Although he said there is a clear role for antibiotic prophylaxis for surgical fields considered “contaminated” and “dirty,” he noted situations in which its use may be more ambiguous for “clean” and “clean-contaminated” surgical fields. He cited a procedure in which an implant or foreign body is placed in the body, which may be considered a “clean” surgical site but nonetheless may increase the risk of infection. He also cited the fact that antibiotics are not regularly used in “clean-contaminated” sites such as in laryngeal or tonsil cases but are used for uninfected sinus cases despite data questioning the necessity.
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November 2024“So, there is a lot to learn,” he said.
In weighing the reasonable risk of infection for a given procedure, he said otolaryngologists also need to consider both the financial and nonfinancial risks of widespread and improper use of prophylactic antibiotics. Risks he cited include patients needing higher doses of different combinations of more expensive medications to treat their disease, alterations to patients’ microbiome, potential for poorer wound healing, and risk of infections like Clostridioides difficile. Recently Dr. Chen and his colleagues published a study showing the adverse consequences, including adverse drug events, suboptimal outcomes, and increased costs, of unnecessarily treating patients who are wrongly mislabeled with a penicillin allergy with prophylactic clindamycin (Laryngoscope. 2023;133:1086-1091; Int Forum Allergy Rhinol. 2023;13:973-978).
Another consideration that may help reduce overuse, he suggests, is changing patient attitudes toward prophylactic antibiotics. “In the past, many patients would not feel they were adequately treated if they didn’t leave the office with some prescription, often an antibiotic,” he said. “Now I am seeing more patients who are relieved I’m holding off on an antibiotic.”
In the end, he hopes, “we as surgeons can be as evidence-based as possible when we prescribe these medications.”
Eric Holbrook, MD, MS, director of the division of rhinology at Massachusetts Eye and Ear and associate professor of otolaryngology–head and neck surgery at Harvard Medical School, both in Boston, who specializes in rhinology and sinus surgery, brings some clarity to the role of prophylactic antibiotics in sinus surgeries based on research he and his colleagues published in 2020 showing no benefit of prophylactic post-operative antibiotics (amoxicillin-clavulanate) over placebo on improving outcomes in patients with chronic rhinosinusitis following endoscopic sinus surgery (ESS) (Int Forum Allergy Rhinol. 2021;11:1047-1055). Although Dr. Holbrook does not routinely prescribe antibiotics after uncomplicated and non-infected surgery for his patients, he and his colleague Stacey Gray, MD, undertook the study because it remains common practice in otolaryngology to prescribe prophylactic antibiotics after ESS.
“Going into the study, we suspected that post-operative antibiotics were not needed for routine sinus surgery cases without evidence of infection,” he said, noting, “It is not totally accepted that post-operative antibiotics are not needed, so people still prescribe them.”
Dr. Holbrook said that the study’s findings disprove the assumption held by many otolaryngologists that prophylactic antibiotics are needed even if there is no evidence of infection during surgery. “I think the main reason otolaryngologists continue to prescribe prophylactic antibiotics is that it has been ingrained in their practice since training,” he said. “It’s what they have always done, and [they] believe that an infection could develop while the sinuses heal from surgery.”
Dr. Holbrook noted that one complicating factor in determining the need for prophylactic antibiotics occurs when the nose and sinuses are packed to prevent bleeding after surgery. “A lot of people are using packing after surgery, and packing can lead to patients being more prone to developing infections,” he said. Although his study did not enroll patients with packing after surgery, and therefore the findings cannot be extrapolated to these patients, he noted that there is little evidence that antibiotics are needed for patients with post-operative packing. He and his colleagues rarely use packing in their practice.
Philip E. Zapanta, MD, a general otolaryngologist at Sovah ENT & Allergy–Danville in Virginia, called it “debatable” whether or not to give antibiotics to patients with nasal packing. “When I trained in the early 2000s, we would always give antibiotics to patients who had packing for epistaxis due to the theoretical risk of toxic shock syndrome,” he said. “Now I don’t prescribe antibiotics to these patients, and patients who were packed by the ER don’t typically have prophylactic antibiotics when I see them in clinic.”
For his post-sinonasal surgery patients who have packings/splints left in place, Dr. Zapanta will give low-dose antibiotics to decrease the foul smell from packings/splints, although he said this may not be fully supported by evidence-based medicine. “For complex sinonasal surgeries, such as those that use grafts, or reconstruction or skull base surgery, I think post-op antibiotics are definitely reasonable, and the general consensus on this is clearer,” he added.
Types of Antibiotics and Duration of Use
Choosing the appropriate prophylactic antibiotic to use depends first on the surgical site and the type of bacteria that may be colonizing there. Other factors include the toxicity and potential adverse effects of the antibiotic on the patient and the antibiotic-resistant patterns found in the hospital environment in which the procedure is performed. Choosing an antibiotic that will kill bacteria (bactericidal) and not one that merely stops proliferation (bacteriostatic) is also important, as is choosing one with the potential to deeply penetrate tissue levels. These are the main criteria cited by sources in this article and detailed more broadly in a recent review by Dr. Zapanta (Medscape. https://emedicine.medscape.com/article/873812-overview).
Cefazolin (IV) and cephalexin (PO) meet most of these criteria, according to Dr. Patel, who said they are the most commonly used antibiotics in the prophylactic setting in head and neck surgeries. He noted that they are best used for gram-positive aerobic bacteria.
More controversial is the effectiveness of cefazolin for anaerobic bacteria or gram-negative bacteria. Dr. Patel said a number of studies show that clindamycin, an antibiotic with theoretically better anaerobic coverage relative to cefazolin, actually is inferior to cefazolin in several studies. “This is interesting because it is the most commonly prescribed prophylactic antibiotic in patients who are penicillin allergic,” he said, adding that it remains unclear if there is a better alternative. He said that while some studies show that antibacterial regimens with increased gram-negative coverage are associated with fewer infectious complications, many studies have failed to show benefit from improved gram-negative coverage, including the addition of aminoglycosides.
“In light of this data, the thinking is maybe you don’t need anything other than cefazolin in many situations,” he said. In cases where better gram-negative coverage may be particularly important, such as large surgical defects involving the aerodigestive track (e.g., laryngectomies or free flaps), he said that either Unasyn (IV) or Augmentin (PO) should be considered.
As to how long prophylactic antibiotics should be used, Dr. Patel said that the data generally show that long-term (defined in most studies as more than 48 to 72 hours) is not more beneficial than short-term (defined as less than 24 hours). “This is also surgery-specific,” he said. “For free flaps or very large head and neck cases, for example, data show that two days may be better than one day, but the evidence is weak.” Dr. Patel noted that it is not uncommon for physicians to prescribe antibiotics for a week or so after surgery but underscored that there is almost no data to suggest that this is beneficial. Ultimately, he said that “decisions to prescribe antibiotics are based on individual surgeon experience and patient factors” but emphasized the importance of understanding the data and using evidence to support our practices.
Mary Beth Nierengarten is a freelance medical writer based in Minnesota.