Chapter 6: Acute Care Surgery

Over the past decade the organization of a new paradigm in the management of acutely ill surgical patients has emerged, one emphasizing surgeons trained in trauma, emergency general surgery, and surgical critical care.¹ The need has been established for a specialized group of surgeons to care for patients with “time sensitive surgical disease” of high acuity, at any time of the day or night, regardless of the patients’ insurance or other social factors.² This comes at a time where we are experiencing an ever-increasing volume of emergency general surgery patients, with estimates revealing in excess of 27.6 million emergency general surgery hospital admission over the past decade.³ To address this need, the specialty of acute care surgery (ACS) was proposed by the American Association for the Surgery of Trauma (AAST). Acute care surgery as initially presented was comprised of trauma, surgical critical care, and emergency surgery. We have redefined the five components of ACS as trauma, surgical critical care, emergency surgery, elective general surgery, and surgical rescue (Fig. 6-1).

In recent years trauma surgery has undergone what some have referred to as an “identity crisis.”⁴ A prevalent opinion among those practicing the specialty was that it was not a sustainable practice model, with low operative volumes, decreasing the median trauma caseload per surgeon to approximately 50 per year.^5,6 Others lament that the days of the trauma surgeon as the master surgical technician have vanished.⁷ In addition to concerns regarding case volumes, the specialty has been plagued by issues with long, unpredictable work hours and high levels of stress, including the high-stake nature of the work.⁸ A 2006 survey of trauma surgeons revealed that 88% of respondents felt that their work caring for the injured was undervalued by society.^5,9 In summary, the majority of trauma surgeons surveyed felt that the specialty required a metamorphosis to remain viable as a career for future surgeons.⁵

Compounding the issue of this disenchantment was the lack of surgical resident interest in pursuing a career in trauma. A 2003 survey of general surgery residents reported that despite 83% of residents desiring fellowship training after residency, only 17% pursued a fellowship in surgical critical care.⁴ Even though the restriction of resident duty hours positively influenced recruitment into general surgery residencies, there clearly existed a need to then encourage these trainees to remain in the “business” of caring for general surgical emergencies. High levels of specialization among residents meant that only a minority of graduates from general surgery residency programs would remain in the true general surgery workforce, addressing the most common surgical emergencies.¹⁰ Overall, the number of general surgeons in the United States fell just more than 25% from 1981 to 2005, with losses noted in both rural and urban areas.¹¹

A survey of emergency department directors conducted in 2010 also highlighted the struggles in maintaining adequate staffing to handle emergency surgical issues: 74% of emergency departments experienced problems with finding specialist coverage in a variety of disciples, 37% of departments having incomplete or no general surgery coverage, and 55% of departments reported inadequate trauma coverage.¹² In the same study, 23% of facilities had lost or downgraded their trauma center level designation due to issues with specialist coverage.¹² The problem extends beyond the emergency department and into the intensive care unit, where national data in the United States point to a growing shortage of critical care providers despite an increasing need.¹³ This is especially crucial in areas such as trauma, where better survival outcomes have been linked with intensive care.¹³

With these clear issues in mind, a task force of the AAST, including members of the American College of Surgeons Committee on Trauma, the Eastern Association for the Surgery of Trauma (EAST), the Western Trauma Association (WTA), and numerous invitees from other surgical and critical care organizations convened to discuss the future of trauma surgery and the formation of what eventually came to be known as acute care surgery (called emergency surgery or visceral surgery in Europe). Results of this discussion and others were initially published in 2005 in the Journal of Trauma, suggesting a pathway to developing ACS into a distinct specialty.⁸ This newly defined specialty was to encompass aspects of trauma surgery, emergency general surgery, and surgical critical care. There was some initial discussion to include components of neurosurgery and orthopedics in ACS. The idea of extending the scope of the ACS surgeon into those surgical subspecialties has waned, although it possesses theoretical advantages for surgeons practicing in more remote locations of the country or in more austere environments.^6,7,8,14 Expansion of trauma practices aside, the marriage of trauma surgery and emergent general surgery is a logical one, as the patients share many similarities in the acute nature of their diseases and the need for aggressive resuscitation and frequent critical care continuity necessary in the pre- and postoperative phases of their illness.^15,16

Establishing an acute care surgery service should be responsive to local needs and is not a “one size fits all” solution.¹⁷ Depending on the needs and desires of each hospital and surgeon group, the practice of emergency general surgery can be fused with trauma and/or critical care; alternatively, it can serve as a stand-alone service.¹⁵ Benefits of organizing an acute care surgery service as seen from a physician standpoint include freeing up valuable time for surgeons who prefer a more elective practice, increased job satisfaction, improved and more controllable lifestyle, increasing revenues, improving quality and timeliness of care, and expanding research and educational opportunities.² Most importantly, the acute care surgery service fills a critical patient need.

In the opinion of the authors, necessary components for acute care surgery to be sustainable as a specialty include the following: maintenance of long-term fulfillment in job satisfaction, lifestyle, and financial compensation; respect for the specialty from our medical and surgical peers; maintenance of a high level of competency in general surgery; and the specialty must be attractive to the new generation of residents in training.¹⁸ Initial efforts in organizing the specialty of acute care surgery seem to be achieving some success with job satisfaction among surgeons.¹⁹

The past decade has observed an exponential increase in the implementation of ACS services, which has provided the impetus to determine the ramifications of this newly defined specialty on important clinical outcomes. Significant improvements in time management and patient outcomes have been noted. Two studies out of Canada show promising results with regards to time making treatment decisions. Implementation of an ACS service at one institution reduced surgical decision time by 15%, presumably due to the more immediate availability of an attending surgeon, and shortened average time-to-stretcher from the waiting area for all patients in the emergency department (ED) by 20%, thereby reducing ED overcrowding.²⁰ Another study showed shorter times to the operating room (OR) for patients (192 vs 221 minutes, p = 0.015) after creating an ACS service, and proportionally less after-hours operative cases as well (60 vs 72.6%, p <0.0001).²¹

Given the common nature of appendicitis, several studies have examined ACS outcomes specific to its treatment. In one of the first published studies examining patient outcomes in an ACS practice model, patients with appendicitis treated by an ACS team compared to patients treated by a traditional general surgery on-call practice model had decreased time from consultation to the OR (3.5 vs 7.6 hours, p <0.05), decreased time from presentation to the ED to the OR (10.1 vs 14.0 hours, p <0.05), decreased rates of appendiceal rupture (12.3% vs 23.3%, p <0.05), decreased complication rates (7.7 vs 17.4%, p <0.05) and decreased hospital length of stay (LOS) (2.3 vs 3.5 days, p <0.001).²² Similar results were reported in other studies comparing ACS to traditional general surgery call, with reduction in patient time-to-surgical evaluation, shorter time to OR, shorter length of stay as well as cost savings.^{21,23,24,25,26,27} This was due to around-the-clock presence of the acute care surgery attending in the hospital, and cases that presented in the night hours were not delayed until the following morning as was the previous practice with the traditional on-call model.²⁵

The influence of an ACS service on biliary pathology (ie, cholecystectomy outcomes) has also been the focus of intense investigation, with several benefits again reported. A study previously discussed showed that the average time for a patient to receive surgical evaluation dropped by 5.84 hours, time to the OR was reduced by more than 25 hours, there were fewer complications, hospital LOS was 1.9 days shorter, and cost savings of approximately $3000 per patient were noted.²³ Similar outcomes have been observed at other institutions. A 2011 study of similar design found shortened average time from ED to OR (24.6 vs 35.0 hours, p = 0.0276), decreased complication rates (7.0% vs 18.5%, p = 0.032), and decreased after-hours cases (5.6% vs 21.0%, p = 0.004).²⁷ Decreased time to OR was also achieved by Lim et al in their 2013 article, though they did not note any significant decreases in complications, conversions to open procedures, or hospital LOS.²⁶ Another study published recently reported that after their institution implemented an ACS service patients went to the OR 5 hours faster on average, more patients had their gallbladder removed in the first 24 hours after presentation (75% vs 59%, p = 0.004), overall hospital LOS was 1.4 days shorter, fewer complications were noted (3.9% vs 13.8%, p = 0.001), and fewer cases were converted from laparoscopic to open (4.2% vs 11.6%, p = 0.013).²⁸

One concern initially raised is that the combination of an emergency general surgery practice and a trauma practice would negatively impact trauma outcomes. Fortunately this concern has not been borne out in the published literature. Multiple studies have shown that despite the increase in workload that occurs with development of an ACS service, times to OR for the injured patient are not significantly affected, and morbidity/mortality rates did not increase.^16,29,30

An addition concern is that the practice of general surgeons not part of the ACS group would be affected by reduced productivity. It is intuitive that trauma and acute care surgeons participating in the ACS service would experience increased operative case volume, and surveyed ACS surgeons have shown increased job satisfaction as a result.³¹ The effects on non-ACS general surgeons have been examined. One study showed that, somewhat surprisingly, wRVU production improved in both ACS and nontrauma general surgeons (44%, 3%) after establishment of an ACS service. Increases in wRVU production for the nontrauma general surgeons were surmised to be a result of fewer interruptions to, and maximal usage of, elective surgery time. Job satisfaction increased for surgeons in both groups of this study.³² Another group found that although their trauma/ACS surgeon wRVU production increased by 140% after integration of emergency general surgery, the nontrauma “elective” general surgeons’ wRVU production fell by 8%.³³ This was counterbalanced somewhat by overall increased billing collections in both groups (129% in ACS group, 7% in general surgery group), resulting in an annual departmental revenue boost in excess of $2 million. General surgeons in the nontrauma group in this study were able to increase their elective caseload by 23%.³³

Finally, implementing an ACS service at a nontrauma hospital has also been examined. Beneficial effects were again observed, with fewer complications, shorter hospital LOS, and monetary savings again noted. After formation of an ACS service, appendectomy complications fell from 13% to 3.7% of cases (p <0.0001), and length of hospital stay decreased from 3.0 to 2.3 days (p <0.0001). Cholecystectomy patients experienced fewer complications as well (9% vs 21%, p = 0.012), and also were noted to have shorter length of stay (3.8 vs 5.3 days, p = 0.0004).³⁴ This study highlights the flexibility and variation of ACS groups between different practice locations and settings. Acute care surgery can encompass trauma surgery, elective and emergent general surgery, and surgical critical care, but it is not bound to include all of these areas in every instance.

The overwhelming majority of general surgery residents graduating in the present day will pursue subspecialty surgical fellowship training after graduation, with most estimates meeting or exceeding 80% of residents.^9,15,35 This effect has extended beyond the university-based training programs and into the community-based programs as well.³⁶ As previously discussed, this raises serious concerns about the remaining number of individuals willing to take call for general surgery emergencies, especially after having completed fellowship training in a more “lifestyle-friendly” specialty.¹⁵ Exacerbating the issue are concerns that new graduates may be inadequately prepared to provide care for the spectrum of acutely ill surgical patients. As knowledge in the field of surgery expands exponentially, the amount of time allotted to acquire remains unchanged or even shortened with the recent of ACGME duty hour restrictions.¹⁵

Guidelines

The guidelines for a 2-year fellowship in ACS have been described by the AAST Committee on Acute Care Surgery.^1,8 The 2-year fellowship incorporates the 9-month ICU rotation requirements of the surgical critical care fellowship with an additional 15 months rotating amongst various emergency and elective surgical services. Some flexibility and variation is allowed depending upon the strengths and weakness of the local training environment and the perceived individual needs of the fellow in training.^1,15,35,37 Each of the 2 years address distinct goals. The first year is primarily designed to fully train the fellow in surgical critical care. As a component of the first year, the fellow also rotates on the trauma and general surgery services and takes night call. The focus of the second year is threefold. It is a period of concentrated elective time learning how to operate in the areas that are most challenging to all trauma surgeons: major hepatic, thoracic, and vascular injuries. Voids that may exist in operative experience and training during the fellow’s residency are filled. In addition, the fellow learns to function as an attending on a busy trauma or general surgery service with help nearby. The need for development and education in ACS extends beyond the operating room, however, and training should facilitate development of a broad base of knowledge regarding the management of acute and often critical surgical illness.³⁸ Some have suggested the inclusion of more knowledge-based curriculum components into the acute care surgery fellowship, addressing topics such as the biologic basis of sepsis or management of specific populations (shock, multiple organ dysfunction, acute kidney injury, etc).³⁹

Case Log

Analysis of acute care surgery fellow case logs from the first year of organized reporting revealed that fellows were performing approximately 200 cases in a year, with a 41–59% split between elective and urgent/emergent, respectively.⁴⁰ Up to half of these cases were in the abdomen, with cases of the head and neck underrepresented. Case requirements for the acute care surgery fellowship have already been revised since their initial release in 2007, with cases now broken up into anatomic subsections with a minimum number of cases required in each section.^1,35 The stated goal is to train surgeons comfortable in numerous anatomic regions. An additional category was added for the logging of ultrasound procedures, both diagnostic and therapeutic.³⁵ Further analysis of fellow case involvement reveals ongoing deficits in head and neck procedures, vascular exposures in the chest, and pediatric cases.⁴¹ Acute care surgery involvement in orthopedic and neurosurgical cases remains rare at most programs.²

As aforementioned, resident caseload during their training may not adequately prepare them for independent practice, with many procedures considered essential by surgical educators being absent or rarely performed during residency.³⁶ Substantial variation is noted between programs and even between individual residents at the same program.³⁶ The number of trauma case residents involved in is decreased due to the nonoperative management of blunt trauma and a decreased incidence of penetrating trauma.¹⁷ The addition of an emergency general surgery service provides significantly increased opportunities for OR cases. In a study at a tertiary academic hospital, 70% of patients on the emergency general surgery service required an operation, compared to only 5.9% of trauma patients.⁴² Review of resident educational activities before and after formation of an ACS service revealed an increased attendance of didactic conferences and independent study while decreasing the number of calls in a month, all while preserving a substantial operative volume.⁴³ This efficiency in training was due to the consolidation of emergency calls into one service, and requiring only one resident team to be present at any given time, as opposed to representatives from multiple surgical teams taking overnight call throughout the month. Establishing an ACS service did not detract from resident case volume or complexity.⁴⁴ Furthermore, the addition of an ACS fellow did not impact resident case numbers, and residents subjectively felt that having a fellow present enhanced their educational experience.⁴⁵

As discussed above, the initial components of acute care surgery included the triad of trauma, emergency general surgery and surgical critical care. We and others have always considered elective general surgery as an essential component of ACS (the fourth pillar of ACS). Much of the skill set and understanding of emergency operative procedures is gained during elective general surgery. What distinguishes the practice of ACS from purely elective general surgery? The practice of elective general surgery focuses on the anatomy and pathology of the disease; for example, colon cancer. This skill set and knowledge base is also essential to the acute care surgery. However, should this patient with colon cancer present critically ill with perforation or obstruction, then a very different scenario evolves, one that necessitates a shift in priorities and a more complex delivery of surgery and health care. It is this additional and primary perturbation in physiology with which the acute care surgeon must contend and does so with a more expansive and integrated skill set.

Further emphasizing the critical need for ACS are national hospital discharge data.⁴⁶ 2010 CDC data reports nearly 35 million hospital discharges in the United States. Forty-one percent are emergent, 25% urgent, 24% elective, and 10% unknown. Furthermore, 10 of the most common diagnoses are within the practice of the acute care surgeon (Fig. 6-2). An important diagnosis on the list is “complication of medical or surgical care”; this accounts for one million hospital discharges yearly. In fact, this is a more common discharge diagnosis than bowel obstruction, appendicitis, and cholelithiasis combined. These patients who are now dealing with a major complication of medical or surgical care may be the most vulnerable of our patients. Time dependent intervention is critical to retrieve these patients from this complication. Twenty-percent of the general surgery patients on our service are admitted with a primary diagnosis of complication; the vast majority from prior operations by other services or hospitals. More than 80% require an operation and more than 50% multiple operations to be “surgically rescued.” Other major components of Surgical Rescue include ICU care, ventilator support, nutritional support, management of sepsis, interventional radiology and surgical subspecialties.⁴⁷ Exquisite understanding of the anatomy and principles of the initial elective operation are essential to surgically rescue the patient from his postoperative complication. The skill set required for Surgical Rescue raises the bar for Acute Care Surgery and requires a team of experienced surgeons and the depth of resources as described above.

Growing interest and experience with ACS and the emergency general surgery patient cohort have prompted initiatives into specialty specific outcomes and quality improvement tracking, similar to what has been previously done in trauma surgery. Analysis of National Surgery Quality Improvement Program (NSQIP) data reveals significantly worse outcomes in operations on emergency general surgery patients versus nonemergent operations of the same type, with significantly higher prevalence of systemic inflammation and other alterations in physiology in the emergent group.⁴⁸ These data have led many to question whether the same outcomes metrics should be applied to emergent versus nonemergent cases of the same operation.⁴⁸ It has been demonstrated that for colorectal surgery specifically, good institutional outcomes on the elective operation side does not necessarily equate to good outcomes on the emergent operation side: emergency general surgery is not merely emergency + general surgery.⁴⁹ Efforts have been made by multiple groups to determine what preoperative characteristics are predictive of worse outcomes in emergency general surgery.^50,51 The Charlson Comorbidity Index has been shown to predict mortality in emergency general surgery patients.⁵² Proposals have been put forth that a database for emergency general surgery cases resembling that of the National Trauma Database would better facilitate outcomes tracking and research, though there appears to be some debate on whether this should be a separate database or included into the trauma database.^53,54 Noted is the lack of correlation between good trauma outcomes and good emergency general surgery outcomes, perhaps offering a more compelling argument to the creation of a similar but separate database for emergency general surgery.⁵⁴