Key messages

• Postoperative antibiotic prophylaxis might not decrease the risk of infection in orbital fracture.
• Postoperative antibiotic prophylaxis probably increase the risk of complications, particularly diarrhea.

What is the evidence.
See evidence matrix  in Epistemonikos later

We found one systematic review [3] including four studies [4],[5],[6],[7], of which only one corresponded to a randomized trial [4]. This table and the summary in general  are based on the latter, since the observational studies did not increase the certainty of the existent evidence nor did they contribute any relevant additional information.

What types of patients were included*

The trial [4] included patients with orbital blow-out fracture that required surgical intervention and with no need of  intensive care; without bacterial infection at the moment of the fracture, bullet wounds, pathological fracture, basilar skull fracture with cerebrospinal fluid rhinorrhoea or intracranial emphysema, history of malignancy or radiation in the head and neck area, known hypersensitivity or allergy to penicillin or other beta-lactam antibiotics, compromised host defense, severe renal insufficiency or lack of compliance.

What types of interventions were included*

The trial [4] compared the use of intravenous amoxicillin/clavulanic acid 1.2g every eight hours from the time of admission to 24 hours after the surgery, followed by four days of orally administered placebo every eight hours, versus the use of intravenous amoxicillin/clavulanic acid 1.2g every eight hours from the time of admission to 24 hours after the surgery, followed by four days of orally administered amoxicillin/clavulanic acid 625 mg every eight hours for four days.

What types of outcomes
were measured

The outcomes reported by the systematic review were postoperative infections and adverse effects (skin rash and diarrhea).

To whom this evidence does and does not apply

• The evidence presented in this summary applies to patients with a low-risk orbital fracture, since the trial included patients that did not require intensive care; without acute pre-existent bacterial infections at the moment of the fracture, bullet wounds, pathological fracture, basilar skull fracture with cerebrospinal fluid rhinorrhoea or intracranial emphysema, history of malignancy or radiation in the head and neck area, known hypersensitivity or allergy to penicillin or other beta-lactamic antibiotics, compromised host defense, severe renal insufficiency or lack of compliance.

• The outcomes presented in the summary of findings table are those considered critical for decision-making, according to the opinion of the authors of this summary. In general, they coincide with the outcomes reported by the systematic reviews identified.

• There is a high degree of uncertainty regarding the possible effects of the intervention . ON the other hand, is is associated to adverse effects, which are not serious, but probably frequent.
• It is not possible to make an adequate balance between benefits and risks, due to the uncertainty regarding the former.

• Even though antibiotics are easily accessible, and of a relatively low cost, it is not possible to make an adequate cost-benefit balance, due to the existing uncertainty.

• According to a report by the American Society of Ophthalmic Plastic and Reconstructive Surgery, 63% of the polled members do not use prophylactic antibiotics on patients with orbital fracture [2]. Among the reasons that may justify this practice are: the fact that most orbital fractures do not require surgical correction, a low incidence of infections associated to orbital fracture (the incidence of post-fracture orbital cellulitis is below 1% [2]); potential risks associated to using antibiotics without a clear justification and the increase in the costs associated to health services [2].
• Faced with the evidence presented in this summary, most patients and physicians should lean towards not using postoperative prophylactic antibiotics for the prevention of infections associated to orbital fracture. However, in high-risk patients the decision may vary depending on the clinical conditions.

Differences between this summary and other sources

• The conclusions in this summary agree with the systematic reviews identified.
• The guideline of the American Academy of Ophthalmology states that, at least in the case of orbital floor fractures, the use of antibiotics is subjected to physician’s judgement [1]. Other guidelines also recognize the lack of evidence to inform the use of prophylactic antibiotics in orbital fracture [2],[8].

• It is probable that the conclusions in this summary might be modified by future evidence, due to the uncertainty about the benefits of the intervention.
• We identified one ongoing trial [9] in the International Clinical Trials Registry Platform of the World Health Organization.
• We did not identify ongoing systematic reviews in the PROSPERO database.