Quick and Short: The Impact of Time to Surgery and Operative Duration on Infection Risk in Emergency Surgery

Authors:
George C Velmahos, Haytham M A Kaafarani, Ikemsinachi C Nzenwa, John O Hwabejire, Michael DeWane, Vahe S Panossian, Yasmin Arda

Body of Abstract:
Background: Emergency surgery (ES) is associated with up to 8 times higher risk of perioperative morbidity and mortality compared to elective surgery. This study aimed to identify the impact of time to surgery and operative duration on infectious complications after ES.

Methods: Using the ACS-NSQIP 2013-2017 database, all ES patients 18 years or older were identified using the variable ‘Emergency Case’. Patients with preoperative sepsis were excluded. The primary outcome was postoperative infectious complications, defined as the presence of any of the following: sepsis, septic shock, surgical site infection (i.e. superficial, deep, and organ space), pneumonia, and urinary tract infection. Multivariable logistic regression analyses that adjusted for age, body mass index, comorbidities, surgical approach, and type of surgery were used to investigate the impact of time to surgery (more than 12 hours) and operative duration (more than 2 hours) on postoperative infection. Sensitivity analyses were performed to examine the same relationship in three subsets of patients: 1) exploratory laparotomy, 2) cholecystectomy, and 3) appendectomy.

Results: Out of a total of 4,299,148 patients, 264,213 ES patients were included, and 24,921 (9.43%) had infectious complications. On univariate analysis, patients with infectious complications were more likely to have preoperative comorbidities (e.g. obesity, diabetes, heart failure), an American Society of Anesthesiologists (ASA) grade of 3 or higher, an open surgical approach, longer time to surgery (50.4% vs. 39.4%, p < 0.001), and a longer operative duration (31.6% vs. 14.3%, p < 0.001). On multivariable analyses, time to surgery longer than 12 hours was associated with a 14% higher risk of postoperative infectious complications (OR 1.14; 95% CI 1.1-1.18), and operative duration greater than 2 hours was associated with twice the risk of infection (OR 1.99; 95% CI 1.91-2.08). Sensitivity analyses showed that prolonged surgery was associated with infectious complications in all cohorts, while delayed surgery was significantly associated with infectious complications only in exploratory laparotomy (Figure 1). Conclusions: Prolonged time to surgery and operative duration are independently associated with increased risk of infectious complications in ES patients. These findings highlight the importance of early and abbreviated surgical interventions in ES.