Different Surgeon, Different Duration: Lack of Consensus on the Appropriate Duration of Antimicrobial Prophylaxis and Therapy in Surgical Practice.

Background: The principles of antimicrobial stewardship promote the appropriate prescribing of agents with respect to efficacy, safety, duration, and cost. Antibiotic resistance often results from inappropriate use (e.g., indication, selection, duration). We evaluated practice variability in duration of antimicrobials in surgical infection treatment (Rx) or prophylaxis (Px). Hypothesis: There is lack of consensus regarding the duration of antibiotic Px and Rx for many common indications. Methods: A survey was distributed to the Surgical Infection Society (SIS) regarding the use of antimicrobial agents for a variety of scenarios. Standard descriptive statistics were used to compare survey responses. Heterogeneity among question responses were compared using the Shannon Index, expressed as natural units (nats). Results: Sixty-three SIS members responded, most of whom (67%) have held a leadership position within the SIS or contributed as an annual meeting moderator or discussant; 76% have been in practice for more than five years. Regarding peri-operative Px, more than 80% agreed that a single dose is adequate for most indications, with the exceptions of gangrenous cholecystitis (40% single dose, 38% pre-operative +24 hours) and inguinal hernia repair requiring a bowel resection (70% single dose). There was more variability regarding the use of antibiotic Px for various bedside procedures with respondents split between none needed (range, 27%-66%) versus a single dose (range, 31%-67%). Opinions regarding the duration of antimicrobial Rx for hospitalized patients who have undergone a source control operation or procedure varied widely based on indication. Only two of 20 indications achieved more than 60% consensus despite available class 1 evidence: seven days for ventilator-associated pneumonia (77%), and four plus one days for perforated appendicitis (62%). Conclusions: Except for peri-operative antibiotic Px, there is little consensus regarding antibiotic duration among surgical infection experts, despite class 1 evidence and several available guidelines. This highlights the need for further high-level research and better dissemination of guidelines.