INTRODUCTION

Background

The concept of acute care surgery (ACS) was proposed by the American Association for the Surgery of Trauma in 2005, bringing together trauma surgery (TS), emergency general surgery (EGS), and surgical critical care [1,2]. In the United States, ACS has helped address surgeon shortages and improve outcomes in time-sensitive cases [3]. Internationally, ACS models vary, yet systematic reviews highlight the role of ACS in improving timeliness of care and reducing complications [4,5].

In Korea, advanced models became necessary due to a shortage of specialist manpower willing to work in TS and EGS, particularly in Seoul, which has approximately 9.6 million residents [6,7]. Seoul National University Hospital, designated as a lower-level trauma center by the local government in 2020, had been performing TS. In July 2023, we initiated the ACS model, expanding our domain to include EGS. As a low-volume trauma center complementing the government-designated regional trauma centers, our institution faced inefficiencies resulting from low trauma volumes, which led to prolonged standby duties and limited opportunities for surgical skill development [8,9].

Objectives

The ACS model was introduced to optimize trauma care and integrate nontrauma emergencies. This study focused on surgery performed by the Division of Trauma and Acute Care Surgery, with the goal of evaluating the comprehensive outcomes observed over the 2 years following the transition to the ACS model.

METHODS

Ethics statement

This study was approved by the Institutional Review Board of Seoul National University Hospital (No. SNUH 2025-21571). The requirement for informed consent was waived due to the use of deidentified data and the retrospective nature of the study.

Study design and patient cohort

This investigation adopted a retrospective, observational study design at our institution, which functions as a tertiary medical center and has been designated as a lower-level trauma center by the local government since 2020. Case acquisition focused on clinical records covering a 54-month period, from March 2021 to August 2025. Inclusion criteria were strictly limited to surgical procedures performed by the Division of Trauma and Acute Care Surgery, whereas trauma operations performed by neurosurgery or orthopedics were excluded. Data were collected from medical records, including diagnoses, procedures, case volumes, and mortality, and all cases were classified as trauma or nontrauma. Descriptive statistics were used to summarize patient and case characteristics.

Staffing and scope evolution

The ACS model was adopted to expand the scope of the existing TS program by integrating nontrauma emergency surgery. This transition was planned as a strategic approach to providing continuous 24/7 coverage for all critically ill patients. To achieve this, a fundamental restructuring of the staffing model was necessary. Initially, during the trauma-only period (March 2021–August 2023), coverage consisted of one TS specialist per day among four surgeons. The staffing composition then shifted to three surgeons covering TS and one covering EGS between September 2023 and February 2024. After adoption of the ACS model (March 2024–August 2025), staffing further transitioned to one surgeon whose primary responsibility was TS and three surgeons whose primary role was EGS. This reallocation ensured round-the-clock availability, with 24/7 in-house coverage provided by one TS specialist and one EGS specialist each day.

RESULTS

A total of 609 operations were performed, consisting of 63 TS cases (10.3%) and 546 EGS cases (89.7%) after adoption of ACS model (March 2024–August 2025). Table 1 details the surgical volumes. Among the 63 trauma operations, primary repair accounted for 35 cases (55.6%), bleeding control for 14 (22.2%), small bowel resection for 6 (9.5%), stoma formation for 4 (6.3%), foreign body removal for 3 (4.8%), and colectomy for 1 (1.6%). Of the 546 nontrauma operations, 156 (28.6%) were cholecystectomy, 109 (20.0%) were appendectomy, 54 (9.9%) were stoma formation, 54 (9.9%) were colectomy, and 52 (9.5%) were small bowel resection.

Table 2 and Fig. 1 present the semiannual distribution of surgical procedures from March 2021 to August 2025. Following ACS implementation, trauma caseload remained stable (10–20 cases semiannually), showing volumes comparable to those before ACS adoption. Nontrauma cases began at 98 during September 2023–February 2024, rose sharply to 170 in March–August 2024, slightly decreased to 115 in September 2024–February 2025, and increased again to 163 in March–August 2025, reflecting a substantial expansion after ACS introduction.

Table 3 summarizes postoperative mortality data. Four trauma patients (6.3%) died, with causes including three cases of hemorrhagic shock and one case of cardiac tamponade. In contrast, seven deaths (1.3%) occurred in the nontrauma cohort: four from sepsis due to intestinal perforation, two associated with advanced malignancy, and one due to massive bronchial hemorrhage.

Table 4 and Fig. 2 show the semiannual distribution of nonoperative management (NOM) cases from March 2021 to August 2025. These NOM cases encompass a wide range of interventions, such as cardiopulmonary resuscitation, extracorporeal membrane oxygenation, ventilator care, supportive care, vascular embolization, chest tube insertion, percutaneous drainage, wound dressing, antibiotic therapy, and postoperative care following orthopedics or plastic surgery procedures. The total number of NOM cases exceeded that of operative trauma cases, supporting the established role of NOM as a mainstream approach in contemporary trauma care.

Table 5 presents semiannual median Injury Severity Score (ISS) and Revised Trauma Score (RTS) values. Median ISS ranged from 4 to 9 across the intervals, with the highest scores observed in September 2024–February 2025 and March–August 2025. Median RTS remained stable at 7.8, with ranges spanning from 0.9 to 7.8. These data suggest that although anatomical severity demonstrated an upward trend pre- and post-ACS implementation, physiological severity indicators remained consistent.

DISCUSSION

Summary of institutional experience

Our facility transitioned from a model devoted exclusively to TS to the ACS model, which encompasses both TS and EGS. This strategic change expanded our role, originally defined by our designation as a lower-level trauma center in 2020, beyond a TS-exclusive framework to actively integrate nontrauma emergency surgery. The data for this observational study focused strictly on operations performed by the Division of Trauma and Acute Care Surgery, fully excluding procedures conducted by neurosurgery or orthopedics. Trauma volumes remained stable (10–20 cases semiannually) after ACS implementation, demonstrating surgical case numbers similar to those recorded before the transition.

Challenges in low-volume trauma centers in Korea

Seoul, a metropolitan city with approximately 9.6 million residents, has one regional trauma center, which alone is insufficient to manage the volume of severe trauma patients. Consequently, the Seoul Metropolitan Government designated three lower-level trauma centers to support the regional trauma center. This aligns with findings from the Park Trauma Center study, which reported that trauma infrastructure remains inadequate relative to the city’s population, emphasizing the need for a system that distributes the burden of trauma care more effectively [10].

However, despite this designation, our center’s low trauma volume resulted in inefficiencies, including burdensome standby duties and limited opportunities for surgical skill development, which constrained both professional growth and financial stability. The issue of suboptimal outcome improvement noted by Kwon et al. [11] and the concern raised by Bae et al. [12] about limited EGS skill development due to low case volume directly reflect the underlying motivation for our strategic shift toward ACS.

The ACS model effectively addressed these challenges by integrating nontrauma cases, which enhanced operational efficiency and contributed to improved financial sustainability [13,14]. This outcome supports the assertion by Lee et al. [13] that the ACS model in Korea can substantially elevate the standard of emergency care for both trauma and nontrauma patients. Moreover, our institutional results affirm that the ACS framework provides a practical and effective solution to the longstanding volume-related constraints encountered by designated centers described by Park et al. [10], ultimately transforming underutilized resources into high-functioning clinical capacity.

Before ACS implementation, one trauma surgeon was dedicated solely to trauma cases. After adopting the ACS model, trauma and nontrauma emergencies often arrived simultaneously, particularly during late-night and early-morning hours. To avoid compromising trauma care, the in-house trauma surgeon continued to prioritize trauma patients, while the ACS surgeon provided essential backup during periods of high volume or severe trauma presentations. As a result, the ACS system maintained the quality of trauma care while improving surge capacity and preserving the existing trauma caseload.

Similar challenges have been documented in Korean studies, where the ACS model contributed to improved clinical outcomes [15,16]. The experiences reported by Chang et al. [15] in managing healthcare crises and by Kim et al. [16] in expanding critical care resources during the COVID-19 pandemic underscore the broader applicability of ACS in reinforcing emergency response systems.

Dedicated ACS specialists are critical not only for maintaining optimal clinical outcomes but also for providing urgently needed specialized medical capacity during mass-casualty events. Consequently, maintaining the ACS model represents a strategic approach that strengthens routine trauma care while supporting regional disaster preparedness. Furthermore, our ACS model, which integrates TS and EGS, adheres to established guidelines such as those governing abdominal injuries and antibiotic use [14]. It is therefore positioned to contribute to standard-setting in the ACS field by ensuring high-quality, evidence-based care for both trauma and nontrauma emergencies.

The semiannual median ISS and RTS data reinforce this stability (Table 5). Median ISS ranged from 4 to 9, while RTS remained consistently at 7.8, indicating no significant shift in overall trauma acuity after ACS implementation. These findings highlight the ACS model’s ability to maintain appropriate levels of trauma care without diminishing trauma caseloads while simultaneously expanding capacity for nontrauma emergencies. This has particular relevance for lower-volume trauma centers such as ours, where ACS can provide a meaningful boost in operational efficiency, and may also offer benefits to major trauma centers by supplying scalable support in high-volume settings.

Global comparison and adaptability

ACS implementation in the United States has been associated with a 20% reduction in trauma mortality and shorter time to operation [3,17,18]. The improvement in trauma care efficiency reported by Britt [19] aligns directly with the enhanced operational efficiency and, to some extent, the improved financial health observed at our institution following ACS implementation. This parallel suggests that the core advantages of the established ACS model are reproducible within the Korean healthcare system.

However, the exclusion of neurosurgical and orthopedic cases may underestimate the full trauma burden in some ACS reports [4,20]. While our study focuses on efficiency gains achieved through ACS integration within the trauma division, the scope limitation noted in these reports indicates that the future evolution of our system—as well as comparable models nationally—should involve expanding toward a fully multidisciplinary ACS team capable of managing polytrauma patients, as recommended by Jurkovich et al. [3]. The finding by Schuster et al. [20], which showed that greater ACS surgeon experience improves patient outcomes, further underscores the benefit of our model in maintaining continuous practice and a sufficiently high case volume for dedicated surgeons.

Although ACS models differ globally, systematic reviews highlight universal benefits in treatment timeliness and improved patient outcomes [5,17,18]. Our successful transition supports this international consensus [5]. Research on laparoscopic emergency surgery in Korea [12] and the establishment of antibiotic guidelines for abdominal injuries [14] illustrate a broader national movement toward standardized and advanced emergency surgical care—a movement strengthened through active implementation within our ACS program.

Furthermore, the adaptability of the ACS model is crucial during crises. The expansion of critical care capacity in regions like Daegu during the COVID-19 outbreak [16] underscores the flexibility inherent in organized emergency care systems. Given that recent analyses of the Korean medical crisis emphasize a persistent manpower shortage [15], the enhanced operational efficiency and sustained surgical volume achieved through our ACS model serve as a practical means of mitigating this chronic shortage by improving surgeons’ skill maintenance and job satisfaction. Accordingly, our ACS success contributes not only to institutional efficiency but also to broader national resilience during public health emergencies.

Future directions

Future trauma systems should seriously consider an ACS model that integrates both TS and EGS. Our institution’s encouraging operational experience can serve as a valuable blueprint for developing a standardized national education and training curriculum for ACS, as strongly advocated by Britt [19]. Furthermore, it is essential to evaluate the clinical impact of implementing the ACS model through multicenter studies using objective indicators such as the ISS. Ultimately, operational data incorporating TS and EGS from our institution may help establish the foundation for future nationwide analyses of ACS performance.

Limitations

This study is limited by its single-center, retrospective design. Additionally, the deliberate exclusion of trauma operations performed by other specialties means that our reported case volumes and mortality rates may not fully reflect the institution’s overall trauma burden. It should also be noted that the hospital’s organizational structure, which includes a separate department for surgical critical care, may differ from systems in other general medical institutions, potentially limiting generalizability.

Conclusions

The transition from the TS model to the ACS model, which includes EGS, successfully increased the efficiency of trauma and emergency surgery within the low-volume environment of a lower-level trauma center, achieving this without reducing the existing trauma caseload. These findings support the adoption of the ACS model in similar Korean facilities and may offer valuable guidance for national policy development concerning EGS in Korea.

ARTICLE INFORMATION

Author contributions

Conceptualization: JWW; Data curation: JYJ; Formal analysis: JWW; Investigation: JWW; Methodology: YSC; Revision: JWW; Validation: HS, CYP; Writing–original draft: JWW, JYJ; Writing–review & editing: YSC, HS, CYP. All authors read and approved the final manuscript.

Conflicts of interest

Chan Yong Park is an editorial board member of this journal, but was not involved in the peer reviewer selection. The authors have no other conflicts of interest to declare.

Funding

The authors received no financial support for this study.

Data availability

Data analyzed in this study are available from the corresponding author upon reasonable request.

Fig. 1.

Semiannual trends in trauma and nontrauma operations (March 2021–August 2025)

Fig. 2.

Semiannual nonoperative management (NOM) cases in trauma and nontrauma (March 2021–August 2025)

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Figure & Data

References

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