Current challenges in the prevention, management and outcomes of surgical site infections in elective colorectal surgery

Abstract

Surgical site infections (SSI) are currently the most frequent healthcare-associated infections in Spain and Europe. Its development increases morbidity and mortality of patients and costs of healthcare system. Colorectal surgery has special relevance since its contaminated nature implies high rates of SSI. Organ-space SSI, the deepest one, is associated with high mortality. All studies in this memory are observational prospective cohort studies including patients undergoing elective colorectal surgery between 2011 and 2014 in 10 hospitals participating in the VINCat Program. In the first study, differences in the risk factors and rates of SSI in colon and rectal surgery were evaluated. The SSI rates in colon and rectal surgery were 16.4% and 21.6% respectively. While male sex was a common risk factor in colon and rectal surgery, the creation of an ostomy was risk factor for organ-space SSI in colon surgery and duration of surgery > percentile 75 of the procedure in rectal surgery. The administration of oral antibiotic prophylaxis (OAP) prior to surgery and laparoscopy were protective factors in both cases. Thirty-day mortality of patients with organ-space SSI was higher in colon surgery than in rectal surgery. In the second article we analyzed the risk factors and microbiology of SSI developed early (7 days) and late (from the 8th to the 30th day) after colorectal surgery. Early-onset SSI occurred mainly in colon surgery and was organ-space SSI, while late-onset SSI occurred more frequently in rectal surgery and were mainly incisional. There were no significant differences in the microbiology of the two infection types. Early-onset SSI were associated with male sex, American Society of Anesthesiologists’ (ASA) classification III-IV and the creation of an ostomy. Late-onset SSI were associated with rectal surgery, longer duration of surgery and prior chemotherapy. OAP and laparoscopic surgery were protective factors in both cases. In the third study we focused on analyzing the antibiotic management and source control of organ-space SSI, as well as factors associated with treatment failure (defined as mortality or persistence of infection’s signs or symptoms 30 days after surgery) in these patients. The 100% of patients with organ-space SSI received antibiotics for a period longer than 15 days and 81% received measures of source control. The overall treatment failure rate was 21.7% (34.2% in organ-space SSI and 9% in incisional SSI). Treatment failure in organ-space SSI was associated with older age, laparoscopy and the need of reoperation. In the fourth study we analyzed the health costs (excess of hospital stay and 30-day mortality) of developing organ-space SSI using a multi-state model that took into account the time-dependent nature of the variable SSI, to avoid overestimation of the effect of SSI. The development of organ-space SSI increased hospital stay by 4.2 days compared to patients who developed incisional SSI and in 9 days compared with those who did not develop SSI. Organ-space SSI increased the mortality risk by 8 times compared to patients who developed incisional SSI and by 10 times compared to patients who did not develop SSI. In the fifth study we analyzed the risk factors, management and prognosis of SSI caused by Pseudomonas aeruginosa. The 9.3% of patients who developed SSI had an isolation of P. aeruginosa (frequently were polymicrobial infections). These patients had a more deteriorated baseline status (higher ASA classification and higher modified National Nosocomial Infections Surveillance index (NNIS)) and longer duration of surgery than patients with SSI caused by other microorganisms. They received antibiotic therapy for a longer period and had higher treatment failure rate (30.6% vs. 20.8%) than the other SSI. Factors independently associated with P. aeruginosa SSI were higher NNIS index and the no-administration of OAP.

Les infeccions de localització quirúrgica (ILQ) són actualment les infeccions relacionades amb l’assistència sanitària més freqüents. Les taxes d’ILQ són especialment altes en cirurgia electiva colorectal. Aquest projecte analitza diferents aspectes de la prevenció, maneig i evolució de les ILQ, i en especial la d’òrgan-espai, en cirurgia electiva colorectal en 10 hospitals del programa VINCat. El primer estudi mostra les diferències entre les cirurgies de colon i recte en quant a prevalença d’ILQ, sent major en cirurgia de recte que de colon i en els factors de risc d’ILQ d’òrgan-espai. En el segon article s’analitzaren els factors de risc i la microbiologia de les SSI desenvolupades de forma precoç (7 dies) i tardana (del 8 al 30è dia) després de la cirurgia. Es van trobar diferents factors de risc per ILQ precoç i tardana, no obstant, no hi van haver diferències significatives en la microbiologia. La profilaxis antibiòtica oral (PAO) i la laparoscòpia van ser factors protectors comuns. El tercer estudi mostra la microbiologia més freqüent i la presència de multiresistència en bactèries Gram-negatives en les ILQs. També analitza el maneig antibiòtic i de control del focus de les ILQ d’òrgan-espai. El fracàs terapèutic de les ILQ d’òrgan-espai a 30 dies de la cirurgia va ser del 34.2%, i es va associar amb l’edat avançada, la laparoscòpia i la necessitat de reoperació. En el quart estudi es van analitzar els costos de salut (excés d'estada hospitalària i mortalitat als 30 dies de la cirurgia) del desenvolupament d’ILQ d’òrgan-espai mitjançant un model multiestat. Els pacients amb ILQ òrgan-espai van presentar una estada hospitalària i mortalitat significativament superior als pacients amb ILQ incisional o que no van desenvolupar ILQ. En el cinquè estudi es van analitzar els factors de risc, el maneig i pronòstic de les ILQ causades per Pseudomonas aeruginosa. Un 9.3% de les ILQ van tenir aïllament de P. aeruginosa. Aquests pacients tenien una classificació American Society of Anesthesiologists’ (ASA) més alta, un índex de National Nosocomial Infections Surveillance (NNIS) més alt, una major durada de la cirurgia, un tractament més llarg i major fracàs terapèutic (30.6% vs. 20.8%) que els pacients amb ILQ d’altres etiologies. Els factors associats de forma independent a ILQ per P. aeruginosa van ser un índex NNIS 1-2 i la no-administració de PAO.