Penicillin allergy in pancreatoduodenectomy leads to a negative impact on surgical site infection and fistula formation

Author(s):
Christopher Towe, Nathaly Llore, Nathalie Hirsch, Jessica Donington, Harvey Pass, Vanessa Ho, NYU Langone Medical Center

Background: Empyema can result as a complication of bacterial pneumonia or thoracic surgery procedures with mortality as high as 15%. Empyema pathogens are poorly described in the modern era. GreaAuthor(s):

Essa M. Aleassa; Nancy Anzolvar; Gareth Morris-Stiff

Background:

Surgical site infections (SSIs) and clinially relevant postoperative pancretaic fistula (CR-POPF) remain important causes of postoperative morbidity for patients undergoing pancreatoduodenectomy (PD). The standard prophylaxis for such patients is a penicillin or cephalosporin with or without anaerobic coverage, however prophylaxis has not been standardized for patients with a penicillin allergy. Anecdotal observation of a higher rate of SSI in such patients prompted further evaluation.

Hypothesis:

The primary hypothesis was that the use of alternative antibiotic regimens in patients reporting a penicillin allergy was associated with an increased rate of SSIs. Furthermore, we hypothesized that many patients proporting an allergy would not in fact have objective evidence of a penicillin allergy. The secondary hypothesis was that many patients proporting an allergy would not in fact have objective evidence of a penicillin allergy, and will have not undergone testing.

Methods:

Prophylactic antibiotics were administered at the time of induction, with ciprofloxacin with metronidazole or vancomycin the most commonly prescribed antibiotics in the case of a penicillin allergy. A prospectively maintained departmental database was used to identify patients and to obtain data on SSIs and CR-POPF. The incidence of SSI and CR-POPF were then compared in patients with and without a penicillin allergy, and specifically those receiving the optimal antibiotic choice of ceftriaxone and metronidazole.

Results:

From January 2014 to December 2017, 329 patients underwent PD of which, 47 (14.3%) patients reported a penicillin allergy and were prescribed alternate SSI prophylaxis, most commonly vancomycin (n=21) or ciprofloxacin and metronidazole (n=15). 12/47 (25.5%) developed an SSI and 7/47 (14.9%) developed a CR-POPF. Of note, none of the patients had formal allergy testing documented in their EMR prior to PD. However, 10 patients were subsequently tested postoperatively (5 by skin esting and 5 by test dosing with penicillin), and all were deemed negative for penicillin allergy. In the same period, 280 without a penicillin allergy underwent PD of which 49/282 (17.4%) developed an SSI and 31/282 (11.0%) a CR-POPF. Of those without penicillin allergy that received the optimal combination of ceftriaxone and metronidazole 18/164 (10.8%) developed an SSI and 6/164 (3.7%) developed a CR-POPF. Both SSI (p=0.012) and POPF (p=0.004) were significantly less common in the Cef&Met compared to the penicillin allergy group.

Conclusions:

The presence of a penicillin allergy and subsequent need for alternative prophylaxis is associated with a significantly increased risk of both SSI and CR-POPF. Given the lack of proof of allergy in the majority of cases, pre-operative testing may help to reduce morbidity in patients undergoing PD by offering them the opportunity of optimal prophylaxis.

ter understanding of common pathogens and risk factors is required to improve empiric treatment. The primary aim of this study is to describe the microbiology of empyema in the modern era.

Hypothesis: We hypothesize that parapneumonic empyema (PNE) and post-surgical empyema (PSE) will be clinically and microbiologically distinct.

Methods: All patients with positive pleural cultures between 4/2007 and 6/2012 were identified from microbiological records. Patient demographics, clinical course and microbiological information were collected. Each acute empyema was classified as PNE or PSE and differences between groups were assessed using the Chi-square test.

Results: A total of 227 microorganisms from 28 genus classes were isolated from 125 patients (74 (64%) male, mean age 61). 120 (97%) required drainage and/or decortication, while 5 were treated with antibiotics alone. Common comorbidities included: a history of immunosuppression (29%), diabetes (19%), and renal disease (14%). Mortality was 15%. Half (47.7%) of the index cultures were polymicrobial. 152 isolates (67%) were gram positive, 56 (25%) were gram negative, 16 (7%) were fungal, and 3 (1%) were unclassified. Only 7% of isolates were obligate anaerobes. The most common organisms were Streptococcus spp (27%) and Staphylococcus spp (25%), followed by Enterococcus spp (9%), Candida (6%), and Pseudomonas (6%). Of 31 isolates of S. aureus, 14 (45%) were methicillin resistant. 29% of the infections were postoperative. Patients with PSE were less likely to have had a preceding pneumonia (28% vs 65%, p<0.05). Patients with PSE had a slightly higher incidence of gram-negative pathogens but this did not reach statistical significance (40% vs 26%, p=0.1). There was no difference in outcome between the PNE and PSE patients.

Conclusions: A wide variety of pathogens were isolated from infected pleural cultures. The most common pathogens isolated were aerobes and gram positives. Polymicrobial infections were common. There was no significant difference in clinical course or pathogens isolated from parapneumonic and post-surgical empyema.