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13. Diaz JJ, Norris PR, Gunter OL, et al. Does regionalization of acute care surgery decrease mortality? J Trauma 2011;71: 442e446. 14. Block EF, Rudloff B, Noon C, et al. Regionalization of surgical services in central Florida: the next step in acute care surgery. J Trauma 2010;69:640e643; discussion 643-644. 15. Kastor JA, Adashi EY. Maryland’s Hospital Cost Review Commission at 40: a model for the country. JAMA 2011;306: 1137e1138. 16. Murray R. Setting hospital rates to control costs and boost quality: the Maryland experience. Health Aff (Millwood) 2009;28:1395e1405. 17. Shafi S, Aboutanos MB, Agarwal S Jr, et al. Emergency general surgery: definition and estimated burden of disease. J Trauma Acute Care Surg 2013;74:1092e1097. 18. Averill RF, Goldfield N, Hughes JS, et al. All Patient Refined Diagnosis Related Groups Version 20.0: Methodology Overview. 3M Health Inform Syst; 2003:1e91. 19. Gale SC, Shafi S, Dombrovskiy VY, et al. The public health burden of emergency general surgery in the United States: a 10-year analysis of the Nationwide Inpatient Sampled2001 to 2010. J Trauma Acute Care Surg 2014;77:202e208. 20. Demetriades D, Martin M, Salim A, et al. Relationship between American College of Surgeons trauma center designation and mortality in patients with severe trauma (Injury Severity Score > 15). J Am Coll Surg 2006;202: 212e215. 21. Diaz JJ, Norris P, Gunter O, et al. Triaging to a regional acute care surgery center: distance is critical. J Trauma 2011;70: 116e119.
Discussion DR LD BRITT (Norfolk, VA): Let me be one of the first to thank Dr Diaz and Dr Narayan and other coauthors for this excellent contribution. I want to particularly commend Dr Jose Diaz for having one of the first effective acute care surgical services when he was on the faculty at Vanderbilt. Now at Maryland, he has continued, along with his colleagues, to be a beacon for this evolving specialty. This manuscript is representative of his excellent work and commitment to advancing acute care surgery. I will not highlight or underscore the limitations of a retrospective methodology, but I do have several questions for the authors. 1. Why would emergency general surgery (EGS) patients with extreme All Patients Refined Severity of Illness (APRSOI) score have increased mortality when they are treated at trauma centers as compared to nontrauma centers? Does this represent a selection bias, where the more severely ill patients go to the trauma centers, and, obviously, the less severely injured patients go to the nontrauma centers? 2. Also among the trauma centers, why would the effect of the lower mortality for moderate APRSOI, be the strongest for Level I trauma centers as compared to Level II trauma centers? The differences between the two are not that much. So tell me, what is the essential component of a Level I trauma center that determines this difference?
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3. What would have been the likely findings and how would the results differ if CPT codes had been used instead of the ICD-9 codes? 4. Because this is a single-system experience in a stable and mature statewide network, how can we generalize this to other regions of the country? 5. How would you make the findings operational?
DR MICHAEL CHANG (Winston-Salem, NC): As acute care surgery continues to evolve, we are seeing a variance of definitions associated with this term. Typically, at academic institutions, it is defined as it is in this well-written paper presented today by the Maryland trauma group; that is, combining trauma, emergency general surgery, and surgical critical care under one group of surgeons. However, penetrance of this model of acute care surgery is variable and heterogeneous from center to center and hospital to hospital. At one end of the spectrum, the trauma surgeons provide all the surgical and perioperative care; at the other, most commonly in community hospitals, all the emergency surgical care, even if the hospital is a trauma center, may be provided by surgeons other than the trauma team. Within these 2 extremes lies a spectrum of involvement. Intuitively, it is attractive to think that the academic model of acute care surgery makes good sense and should result in improved outcomes for patients with emergent general surgical problems, especially at the moderate to extreme levels of illness. Trauma centers already have in place well-developed ICU care teams, operating rooms that are immediately available, multidisciplinary teams to care for these patients, and perhaps most importantly, a cadre of surgeons who are willing and available to operate at any time on the sickest of patients. However, we really don’t know yet that this is true, and if true, what part of the trauma center model explains the variance in outcomes, should one exist. This paper represents an important step in working toward this goal, and, as such, should be looked at carefully. Given this background, I think an important potential weakness of this study is the use of trauma center designation as a marker of the presence of an acute care surgery service, especially at Level II and Level III centers, as, often, these hospitals will likely have a separate group of general surgeons practicing in a community environment for whom the EGS patients represent a significant portion of their case volume. Thus, in this setting, one cannot be certain that the trauma team is touching the EGS patients. I have 4 questions for the authors: 1. How do we know that the trauma surgeons participated significantly in the care of these patients at the trauma centers, especially at the Level II and Level III centers? 2. What do the authors think explains the improvement in outcome in the moderately sick patients? Do we know that trauma techniques and concepts, such as damage control and staged laparotomies, are applicable to the EGS population? We intuitively think this should be the case, but analysis of the data at our institution suggests that criteria for damage
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control in EGS patients may be different than that for trauma surgeons, so I am not sure that this assumption is valid. 3. Do we know who was staffing the ICUs in these compared hospitals? Perhaps the differences observed might be due to the existence of a surgeon-directed SICU. 4. The lower rate of ED admission and the higher mortality in the extreme group leads me to speculate, as the authors do, that the mortality is higher in the extreme group because the trauma centers are located at safety net hospitals for their referral region. In this era of increasing focus on institutional benchmarking for risk-adjusted outcomes, do the authors believe that this may serve as a disincentive for these institutions to accept these gravely ill patients? DR ADDISON MAY (Nashville, TN): Do you know if any of the nontrauma centers in your state have a surgical hospitalist system, so basically a trauma center without a trauma population? Second, have you done your analysis in patients only admitted through the ED? In the bigger hospitals, you will have a higher percentage of complications that are treated by the emergency general surgery service from other large services, and that may skew your outcomes significantly. DR MAYUR NARAYAN: Dr Britt, to answer your first question, why would EGS patients with extreme APRSOI increase mortality vs nontrauma centers? Is there a selection bias? There definitely very well could be a selection bias. Again, we are assuming here. We do not have transfer data. But it is likely that the patients who were seen at our Level I center were transferred in from an outside facility. This holds true with our data that show that a majority of these patients, 50%, only came from the Level I trauma centers, vs 75% for the lesser Level I, Level II, and Level III trauma centers. Your second question regarding lower mortality for the moderate APRSOI for Level I vs Level II, this definitely could be a result of the existence of an academic program at Level I centers. Again, although staffing may not differ as much, the presence of an academic program at Level I centers may be contributing to that difference in mortality. Question 3, would our results differ if we used CPT? This could potentially provide more granularity in our results. This may be a methodology we look to in the future. Question 4, how can we generalize this to other studies and other systems? I think we need to be careful before we start generalizing. Again, Maryland is a very mature system that has been in existence since the late 1960s. We need to be careful before we start taking this model and applying it to other systems. But our results are interesting. On your question, Dr Chang, on whether we confirmed that the trauma critical care surgeons at these centers are performing the operations? Again, the study provides a 30,000-foot view of EGS in Maryland looking at all 621 ICD codes. We agree that using the trauma center designation as a marker for acute care
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surgery services for Level II and Level III may be a potential weakness. Moving forward, we plan to narrow our focus to match the top 10 ICD codes found in the Health Services Cost Review Commission (HSCRC) database with those same codes at the University of Maryland. We may not be able to delineate trauma surgeon participation on a case-by-case basis given the inputs of the HSCRC database. We do know the staffing of Level I and Level II, both are staffed by trained trauma surgeons. A limited number of Level III centers do have call overlap with community general surgeons. The improvement in outcomes seen in the moderately sick severity of illness score group may be a good example of the rule: have the right patient at the right place at the right time. These patients are likely processed quickly through a system to definitive care, and this is leading to improved outcomes. Again, our data show that patients seen at Level II and Level III centers were likely to present at the emergency room 75% of the time, vs only 50% of those seen at Level I centers. The difference seen may be a result of the Level I patients being transferred in, as I previously mentioned. Regarding if trauma techniques are applicable to EGS patients, emergency surgery techniques, such as damage control-staged laparotomy, apply to a broad range of emergency scenarios, the basic principles of which are similar for both trauma and EGS patients, although we agree that the criterion may differ. But both trauma and EGS are time-sensitive diseases, with management focused on early goal-directed therapy. The differences need to be further elucidated in this setting. Regarding the ICU staffing of the compared hospitals and whether differences observed might be due to the existence of surgeon-directed SICU, again, we do know the staffing of Level I and Level II centers in the state of Maryland, but we will need to further study the impact of resources available on outcomes. On your final question regarding institutional benchmarking and disincentives, this is an area that we clearly need to focus on. The current structure has undoubtedly placed tertiary and quarternary care centers in a Catch-22 situation. At the end of the day, acute care surgeons at major academic centers will still continue to take care of the sickest patients. This includes patients who are transferred in from surgeons and hospitals who may not feel comfortable managing them. As a result, it will be important to stratify based on severity of illness to make sure we are comparing apples to apples and to protect high-level centers from getting penalized. To address Dr May’s question on whether we know if nontrauma centers have surgical hospitals in their system? The answer is, in our model, no, currently that is not the staffing model of those hospitals in Maryland. Finally, have we done analysis only for patients in the emergency room? This is a great question. I think this is a future area of study for us, as this may be contributing to some of the differences that we have seen.