28 Importance of initial source control and appropriate empiric anti-infective treatment in complicated intra-abdominal infections

Aim Complicated intra-abdominal infections (cIAI) (that is secondary or tertiary peritonitis, intra-abdominal abscesses) are frequent and require source control (surgery or radiologic drainage) and anti-infective treatment (AIT). The course of cIAI can be complicated by incomplete source control or recurrent peritonitis/abscesses, which need re-interventions and prolonged AIT. Therefore, the optimal management of these cases is difficult to establish. The goal of our study was to describe the management of cIAI in our center and identify risk factors for failure. Methods We conducted a monocentric retrospective study over one year on adult inpatients who underwent surgical/radiological drainage procedures for cIAI. The primary composite endpoint was failure defined as infection recurrence, or death of any cause, or palliative care at 30 days after the initially planned intervention(s). The effectiveness of the initial source control was evaluated based on the adequacy between the type of intervention and the extension of the infection. Characteristics of patients, infections, and management were compared between success and failure groups. The adequacy of empirical AIT was evaluated based on the susceptibility of cultured organisms. Results Our study included 68 patients (36 men and 32 women) with a median age of 69 years old. cIAI were mostly originating from postoperative sources (47%) and colorectal non-diverticular perforations (21%). Most patients presented with peritonitis (86%). One-third of patients presented with sepsis/septic shock (38 %). Initial interventions for source control included laparotomies in 32 (48%), laparoscopies in 16 (24%), radiologic drainages in 16 (24%), and endoscopic drainages in 3 (4%) patients. Infections recurred during AIT in 28 cases (78%) and more than 48 h after the end of AIT in 8 cases (22%). Outcomes were classified as failure or success in 36 (53%) and 32 (47%) cases, respectively. No significant difference in comorbidities were observed between both groups. Abscesses at diagnosis, defined as collections detected on the diagnostic CT scan or during the index intervention, were more common in patients with failure (P = 0.028). In univariate analysis, failure was associated with presumed incomplete source control after initial intervention (P = 0,007), inappropriate empiric AIT (P = 0,006) and longer total duration of AIT (P = 0,008). There was no difference in the use of empiric extended spectrum antibiotics (carbapenems, vancomycin) between both groups. Conclusion In our population of various cIAI sources, initial management failed in 53% of the cases. Our analysis highlights the importance of initial appropriate AIT and thorough source control in cIAI. These findings emphasize the need for a structured approach to optimize both AIT and surgical/radiologic interventions in cIAI management. Trends associated with failure in cIAI management found in this preliminary analysis should be verified with further analyses and a larger dataset.