J Trauma Acute Care Surg Volume 78, Number 6
Letters to the Editor
with a low risk of postoperative major complications or death, whereas a low score is associated with an increased risk. Because the above factors are not included in data analysis, we cannot exclude the possibility that any imbalance in the above factors would have confounded interpretation of their results.2 Finally, besides the operative risk, health status and comorbidities are mostly important determinants of postoperative morbidity and mortality. In this study, EGS patients were notably older and had more chronic illnesses and comorbid conditions. Also, EGS patients were more likely to have partially/totally dependent functional status, American Society of Anesthesiologists physical status classification 4 or higher, sensorium impairment, and sepsis or septic shock. In our opinion, no matter how refined the adjustment is for differences in health status and comorbid burden, it is never possible to ensure a complete adjustment for differences among patients with EGS and non-EGS. EGS may be only a synthetic manifestation of worse health status and heavier comorbid burden that can markedly increase postoperative morbidity and mortality. A ‘‘kitchen sink’’ approach of adjusting for all available variables with multivariable analysis may lead to overadjustment and therefore bias the true effects of EGS itself on postoperative outcomes. Thus, it is not affirmed that association between EGS and excess postoperative morbidity and mortality in this study is a causal relationship. We argue that great caution must be taken when interpreting the findings of this retrospective study, as it has great inherent bias that cannot be overcome by statistical adjustment. *The authors declare no conflict of interest.
Fu Shan Xue, MD Gao Pu Liu, MD Rui Ping Li, MD Department of Anesthesiology Plastic Surgery Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing, China
REFERENCES 1. Havens JM, Peetz AB, Do WS, et al. The excess morbidity and mortality of emergency general surgery. J Trauma Acute Care Surg. 2015; 78(2):306Y311. 2. Moonesinghe SR, Mythen MG, Das P, et al. Risk stratification tools for predicting morbidity and mortality in adult patients undergoing major surgery: qualitative systematic review. Anesthesiology. 2013;119(4):959Y981. 3. Musallam KM, Tamim HM, Richards T, et al. Preoperative anaemia and postoperative outcomes in non-cardiac surgery: a retrospective cohort study. Lancet. 2011;378(9800): 1396Y1407.
4. Arozullah AM, Daley J, Henderson WG, et al. Multifactorial risk index for predicting postoperative respiratory failure in men after major noncardiac surgery. The National Veterans Administration Surgical Quality Improvement Program. Ann Surg. 2000;232(2):242Y253. 5. Wu WC, Smith TS, Henderson WG, et al. Operative blood loss, blood transfusion, and 30-day mortality in older patients after major noncardiac surgery. Ann Surg. 2010; 252(1):11Y17.
Re: Association of emergency general surgery with excess postoperative morbidity and mortality In Reply: e thank Dr. Xue and colleagues for their comments on our recent article, ‘‘The excess morbidity and mortality of emergency general surgery.’’1 The goal of this study was to quantify the excess burden of morbidity and mortality from emergency general surgery (EGS) after controlling for patient factors. We agree that our study suffers from many of the same limitations as other large database studies and have carefully considered the points raised by Dr. Xue and his colleagues. With regard to the procedural risk, our study included 14 specific current procedural terminology (CPT) codes corresponding to four types of procedures commonly performed in both elective and emergency surgery. The specific codes were included in Appendix A and include colectomy, enterectomy, ventral hernia repair, mesenteric revascularization, and aortic reconstruction. The type of procedure was controlled for in our multivariate analysis. We did not calculate the patients ‘‘operative risk’’ using a scoring system such as the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). Instead, we used all variables from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) preoperative risk assessment, which contains the variables used to derive the ACS-NSQIP risk calculator, a validated, highly accurate tool for estimating patients’ risk of postoperative death or complication.2 We feel that we have adequately controlled for operative risk by including the specific procedure and the ACS-NSQIP preoperative risk assessment variables in our model. Adding a risk score based on variables already included in the
W
model would not have increased the rigor of our model. We absolutely agree that preoperative laboratory values such as hematocrit, creatinine, and albumin have been associated with postoperative complications. The ACSNSQIP risk calculator is highly accurate, even though it does not include these variables. We did exclude those values from our model because there were a large number of missing values from the ACS-NSQIP data set. In our analysis, we imputed the missing data and included those values in Table 2. With respect to intraoperative management, we used the ACS-NSQIP database, which is an excellent source of preoperative and postoperative clinical data, but did not include intraoperative data. We agree that intraoperative factors greatly influence morbidity and mortality and noted the absence of intraoperative data as a limitation in our study. We do believe that the increased morbidity and mortality found in EGS when compared with the same procedure performed electively is the result of many factors including patient factors, hospital factors, and intraoperative factors. Although the Surgical Apgar Score is an excellent tool developed at our institution for predicting postoperative risk, it has not been independently validated in EGS.3 We agree that it is difficult to adjust for differences in health status and comorbid conditions among EGS and non-EGS patients, but we disagree with the assertion of Dr. Xue and colleagues that it is impossible. It is correct that the EGS patients in our study were sicker in nearly every parameter we measured (age, comorbid illness, functional status, etc.), but this is an expected phenomenon of any study comparing EGS and non-EGS patients. We used currently accepted statistical methods to address this limitation in the best possible way. In this study, we set out to refute the idea that the increased morbidity and mortality seen in EGS is solely caused by a ‘‘manifestation of worse health status and heavier comorbid burden.’’ This theory implies that although EGS patients are more than five times more likely to die, there would be no means of improving outcomes once the patient presents with a surgical emergency. We believe our results support the idea that there are areas independent of patient factors where we can do better, even if the specific factors are not fully identified by this study. Our goal was to quantify the increased burden of morbidity and mortality of EGS after controlling for patient factors to determine that portion of the burden of morbidity and mortality that can be addressed even after the patient presents for emergency care. When controlling for patient factors, EGS patients were 39% more likely to die.
* 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
1235
J Trauma Acute Care Surg Volume 78, Number 6
Letters to the Editor
We are currently working to identify intraoperative and hospital-level risk factors that contribute to that burden so that we can identify appropriate targets for quality improvement. We appreciate the input from Dr. Xue and colleagues. We hope we have adequately addressed their concerns and thank the editors for the opportunity to respond. *The authors declare no conflicts of interest.
Joaquim M. Havens, MD Allan B. Peetz, MD Division of Trauma Burns and Surgical Critical Care Brigham and Women’s Hospital Boston, MA
REFERENCES 1. Havens JM PA, Do WS, Cooper Z, et al. The excess morbidity and mortality of emergency general surgery. J Trauma Acute Care Surg. 2015;78(2):306Y311. 2. Bilimoria KY, Liu Y, Paruch JL, et al. Development and evaluation of the universal ACS NSQIP surgical risk calculator: a decision aid and informed consent tool for patients and surgeons. J Am Coll Surg. 2013;217(5):833Y842, e831Y833. 3. Gawande AA, Kwaan MR, Regenbogen SE, et al. An Apgar score for surgery. J Am Coll Surg. 2007;204(2):201Y208.
Routine whole-body computed tomography in major trauma resuscitation: From ‘‘donut of death’’ to ‘‘do not without’’? To the Editor: e read with interest the recent systematic review and meta-analysis comparing whole-body computed tomography (WBCT) with selective imaging in major trauma.1 This meta-analysis is one among at least four other recent similar attempts at collecting and aggregating data from several different studies.2Y5 Only two of the metaanalyses have accumulated data that show an associated reduced mortality by WBCT,1,3 notably with somewhat different studies included. Both studies are heavily skewed by the inclusion of the more than 16,000 trauma patients with hemodynamic instability reported from the German Trauma
W
1236
Registry. It should be noted that while searching the same question, the investigators arrive at varying numbers of retrieved studies, somewhat different results, and variation in the number of included studies/ patients. This is partially explained not only by the difference in time between each systematic review performed but also by the problem in defining appropriate inclusion and exclusion criteria. The aggregated data seem conflicting, although the most recent meta-analyses demonstrate a statistically significant reduction in mortality with the routine use of WBCT.1,3 Despite the apparently positive findings favoring WBCT for trauma patients, one cannot exclude bias or confounders in the conducted metaanalyses. As noted by Surendran et al.,2 there are several unresolved issues with the routine application and use of ‘‘panscans.’’ The vast majority of included patients stem from one trauma system, namely, the 211 hospitals volunteering in the German Trauma Registry. One thus needs to investigate if the results also apply to systems outside this region. Because it seems to be associated (as no causality can be claimed) with reduced mortality, it seems imperative to investigate what exactly may explain this effect. Sick patients do not get better from being scanned. It must be a selection before WBCT or, alternatively, what happens after WBCT that ultimately changes the outcome for some patients (the number needed to treat is at least 20). Trauma patients die of central nervous system injury, bleeding, and organ failure. Thus for whom, why, and how WBCT may change the risk of death are highly intriguing and unresolved questions. Rather than claiming that randomized trials in this area would be unethical at this point, we suggest such trials to be sorely needed and most wantedVone is the awaited REACT-2 trial that is underway (www.clinicaltrials.gov # NCT01523626). The conflicting available data suggest this as an area for which alternative methods to generate large-scale, international collaboration should be sought. The increasing peer pressure and request of ‘‘omni-scanning’’ in trauma, without considering the risk associated with radiation, need to be addressed in well-designed, prospective studies to allow for the best decision making.
*The authors declare no conflicts of interest.
Jon K. Narvestad, MD Kjetil SLreide, MD, PhD Department of Gastrointestinal Surgery Stavanger University Hospital Stavanger, Norway
REFERENCES 1. Caputo ND, Stahmer C, Lim G, et al. Wholebody computed tomographic scanning leads to better survival as opposed to selective scanning in trauma patients: a systematic review and meta-analysis. J Trauma Acute Care Surg. 2014;77(4):534Y539. 2. Surendran A, Mori A, Varma DK, et al. Systematic review of the benefits and harms of whole-body computed tomography in the early management of multitrauma patients: are we getting the whole picture? J Trauma Acute Care Surg. 2014;76(4):1122Y1130. 3. Jiang L, Ma Y, Jiang S, et al. Comparison of whole-body computed tomography vs selective radiological imaging on outcomes in major trauma patients: a meta-analysis. Scand J Trauma Resusc Emerg Med. 2014;22(1):54. 4. van Vugt R, Kool DR, Deunk J, et al. Effects on mortality, treatment, and time management as a result of routine use of total body computed tomography in blunt high-energy trauma patients. J Trauma Acute Care Surg. 2012;72(3):553Y559. 5. Sierink JC, Saltzherr TP, Reitsma JB, et al. Systematic review and meta-analysis of immediate total-body computed tomography compared with selective radiological imaging of injured patients. Br J Surg. 2012;99(Suppl 1):52Y58.
Re: Routine whole-body computed tomography in major trauma resuscitation: From ‘‘donut of death’’ to ‘‘do not without’’? In Reply: e would like to thank Drs. Narvestad and Soreide for their thoughtful and insightful editorial. We initiated this metaanalysis because we were equally frustrated (but intrigued) with the progression toward routine application of whole-body computed tomography (WBCT) or ‘‘pan-scan’’ among trauma patients. We aimed to perform a rigorous systematic review that was as inclusive as possible, and then, we had to follow the data to their logical conclusion. We completely agree that a large, wellexecuted randomized trial (that will hopefully be reported from the REACT-2 Trial) would shed a great deal of light on the value of WBCT in trauma. However, until such studies are available, we have to base decisions on the best available studies. It is surprising to criticize our meta-analysis because one study constitutes too many of the total patients. The results from more than 16,000 patients from 211 hospitals should be seen as a valuable contributionVnot as a
W
* 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Letters to the Editor
with a low risk of postoperative major complications or death, whereas a low score is associated with an increased risk. Because the above factors are not included in data analysis, we cannot exclude the possibility that any imbalance in the above factors would have confounded interpretation of their results.2 Finally, besides the operative risk, health status and comorbidities are mostly important determinants of postoperative morbidity and mortality. In this study, EGS patients were notably older and had more chronic illnesses and comorbid conditions. Also, EGS patients were more likely to have partially/totally dependent functional status, American Society of Anesthesiologists physical status classification 4 or higher, sensorium impairment, and sepsis or septic shock. In our opinion, no matter how refined the adjustment is for differences in health status and comorbid burden, it is never possible to ensure a complete adjustment for differences among patients with EGS and non-EGS. EGS may be only a synthetic manifestation of worse health status and heavier comorbid burden that can markedly increase postoperative morbidity and mortality. A ‘‘kitchen sink’’ approach of adjusting for all available variables with multivariable analysis may lead to overadjustment and therefore bias the true effects of EGS itself on postoperative outcomes. Thus, it is not affirmed that association between EGS and excess postoperative morbidity and mortality in this study is a causal relationship. We argue that great caution must be taken when interpreting the findings of this retrospective study, as it has great inherent bias that cannot be overcome by statistical adjustment. *The authors declare no conflict of interest.
Fu Shan Xue, MD Gao Pu Liu, MD Rui Ping Li, MD Department of Anesthesiology Plastic Surgery Hospital Chinese Academy of Medical Sciences and Peking Union Medical College Beijing, China
REFERENCES 1. Havens JM, Peetz AB, Do WS, et al. The excess morbidity and mortality of emergency general surgery. J Trauma Acute Care Surg. 2015; 78(2):306Y311. 2. Moonesinghe SR, Mythen MG, Das P, et al. Risk stratification tools for predicting morbidity and mortality in adult patients undergoing major surgery: qualitative systematic review. Anesthesiology. 2013;119(4):959Y981. 3. Musallam KM, Tamim HM, Richards T, et al. Preoperative anaemia and postoperative outcomes in non-cardiac surgery: a retrospective cohort study. Lancet. 2011;378(9800): 1396Y1407.
4. Arozullah AM, Daley J, Henderson WG, et al. Multifactorial risk index for predicting postoperative respiratory failure in men after major noncardiac surgery. The National Veterans Administration Surgical Quality Improvement Program. Ann Surg. 2000;232(2):242Y253. 5. Wu WC, Smith TS, Henderson WG, et al. Operative blood loss, blood transfusion, and 30-day mortality in older patients after major noncardiac surgery. Ann Surg. 2010; 252(1):11Y17.
Re: Association of emergency general surgery with excess postoperative morbidity and mortality In Reply: e thank Dr. Xue and colleagues for their comments on our recent article, ‘‘The excess morbidity and mortality of emergency general surgery.’’1 The goal of this study was to quantify the excess burden of morbidity and mortality from emergency general surgery (EGS) after controlling for patient factors. We agree that our study suffers from many of the same limitations as other large database studies and have carefully considered the points raised by Dr. Xue and his colleagues. With regard to the procedural risk, our study included 14 specific current procedural terminology (CPT) codes corresponding to four types of procedures commonly performed in both elective and emergency surgery. The specific codes were included in Appendix A and include colectomy, enterectomy, ventral hernia repair, mesenteric revascularization, and aortic reconstruction. The type of procedure was controlled for in our multivariate analysis. We did not calculate the patients ‘‘operative risk’’ using a scoring system such as the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM). Instead, we used all variables from the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) preoperative risk assessment, which contains the variables used to derive the ACS-NSQIP risk calculator, a validated, highly accurate tool for estimating patients’ risk of postoperative death or complication.2 We feel that we have adequately controlled for operative risk by including the specific procedure and the ACS-NSQIP preoperative risk assessment variables in our model. Adding a risk score based on variables already included in the
W
model would not have increased the rigor of our model. We absolutely agree that preoperative laboratory values such as hematocrit, creatinine, and albumin have been associated with postoperative complications. The ACSNSQIP risk calculator is highly accurate, even though it does not include these variables. We did exclude those values from our model because there were a large number of missing values from the ACS-NSQIP data set. In our analysis, we imputed the missing data and included those values in Table 2. With respect to intraoperative management, we used the ACS-NSQIP database, which is an excellent source of preoperative and postoperative clinical data, but did not include intraoperative data. We agree that intraoperative factors greatly influence morbidity and mortality and noted the absence of intraoperative data as a limitation in our study. We do believe that the increased morbidity and mortality found in EGS when compared with the same procedure performed electively is the result of many factors including patient factors, hospital factors, and intraoperative factors. Although the Surgical Apgar Score is an excellent tool developed at our institution for predicting postoperative risk, it has not been independently validated in EGS.3 We agree that it is difficult to adjust for differences in health status and comorbid conditions among EGS and non-EGS patients, but we disagree with the assertion of Dr. Xue and colleagues that it is impossible. It is correct that the EGS patients in our study were sicker in nearly every parameter we measured (age, comorbid illness, functional status, etc.), but this is an expected phenomenon of any study comparing EGS and non-EGS patients. We used currently accepted statistical methods to address this limitation in the best possible way. In this study, we set out to refute the idea that the increased morbidity and mortality seen in EGS is solely caused by a ‘‘manifestation of worse health status and heavier comorbid burden.’’ This theory implies that although EGS patients are more than five times more likely to die, there would be no means of improving outcomes once the patient presents with a surgical emergency. We believe our results support the idea that there are areas independent of patient factors where we can do better, even if the specific factors are not fully identified by this study. Our goal was to quantify the increased burden of morbidity and mortality of EGS after controlling for patient factors to determine that portion of the burden of morbidity and mortality that can be addressed even after the patient presents for emergency care. When controlling for patient factors, EGS patients were 39% more likely to die.
* 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
1235
J Trauma Acute Care Surg Volume 78, Number 6
Letters to the Editor
We are currently working to identify intraoperative and hospital-level risk factors that contribute to that burden so that we can identify appropriate targets for quality improvement. We appreciate the input from Dr. Xue and colleagues. We hope we have adequately addressed their concerns and thank the editors for the opportunity to respond. *The authors declare no conflicts of interest.
Joaquim M. Havens, MD Allan B. Peetz, MD Division of Trauma Burns and Surgical Critical Care Brigham and Women’s Hospital Boston, MA
REFERENCES 1. Havens JM PA, Do WS, Cooper Z, et al. The excess morbidity and mortality of emergency general surgery. J Trauma Acute Care Surg. 2015;78(2):306Y311. 2. Bilimoria KY, Liu Y, Paruch JL, et al. Development and evaluation of the universal ACS NSQIP surgical risk calculator: a decision aid and informed consent tool for patients and surgeons. J Am Coll Surg. 2013;217(5):833Y842, e831Y833. 3. Gawande AA, Kwaan MR, Regenbogen SE, et al. An Apgar score for surgery. J Am Coll Surg. 2007;204(2):201Y208.
Routine whole-body computed tomography in major trauma resuscitation: From ‘‘donut of death’’ to ‘‘do not without’’? To the Editor: e read with interest the recent systematic review and meta-analysis comparing whole-body computed tomography (WBCT) with selective imaging in major trauma.1 This meta-analysis is one among at least four other recent similar attempts at collecting and aggregating data from several different studies.2Y5 Only two of the metaanalyses have accumulated data that show an associated reduced mortality by WBCT,1,3 notably with somewhat different studies included. Both studies are heavily skewed by the inclusion of the more than 16,000 trauma patients with hemodynamic instability reported from the German Trauma
W
1236
Registry. It should be noted that while searching the same question, the investigators arrive at varying numbers of retrieved studies, somewhat different results, and variation in the number of included studies/ patients. This is partially explained not only by the difference in time between each systematic review performed but also by the problem in defining appropriate inclusion and exclusion criteria. The aggregated data seem conflicting, although the most recent meta-analyses demonstrate a statistically significant reduction in mortality with the routine use of WBCT.1,3 Despite the apparently positive findings favoring WBCT for trauma patients, one cannot exclude bias or confounders in the conducted metaanalyses. As noted by Surendran et al.,2 there are several unresolved issues with the routine application and use of ‘‘panscans.’’ The vast majority of included patients stem from one trauma system, namely, the 211 hospitals volunteering in the German Trauma Registry. One thus needs to investigate if the results also apply to systems outside this region. Because it seems to be associated (as no causality can be claimed) with reduced mortality, it seems imperative to investigate what exactly may explain this effect. Sick patients do not get better from being scanned. It must be a selection before WBCT or, alternatively, what happens after WBCT that ultimately changes the outcome for some patients (the number needed to treat is at least 20). Trauma patients die of central nervous system injury, bleeding, and organ failure. Thus for whom, why, and how WBCT may change the risk of death are highly intriguing and unresolved questions. Rather than claiming that randomized trials in this area would be unethical at this point, we suggest such trials to be sorely needed and most wantedVone is the awaited REACT-2 trial that is underway (www.clinicaltrials.gov # NCT01523626). The conflicting available data suggest this as an area for which alternative methods to generate large-scale, international collaboration should be sought. The increasing peer pressure and request of ‘‘omni-scanning’’ in trauma, without considering the risk associated with radiation, need to be addressed in well-designed, prospective studies to allow for the best decision making.
*The authors declare no conflicts of interest.
Jon K. Narvestad, MD Kjetil SLreide, MD, PhD Department of Gastrointestinal Surgery Stavanger University Hospital Stavanger, Norway
REFERENCES 1. Caputo ND, Stahmer C, Lim G, et al. Wholebody computed tomographic scanning leads to better survival as opposed to selective scanning in trauma patients: a systematic review and meta-analysis. J Trauma Acute Care Surg. 2014;77(4):534Y539. 2. Surendran A, Mori A, Varma DK, et al. Systematic review of the benefits and harms of whole-body computed tomography in the early management of multitrauma patients: are we getting the whole picture? J Trauma Acute Care Surg. 2014;76(4):1122Y1130. 3. Jiang L, Ma Y, Jiang S, et al. Comparison of whole-body computed tomography vs selective radiological imaging on outcomes in major trauma patients: a meta-analysis. Scand J Trauma Resusc Emerg Med. 2014;22(1):54. 4. van Vugt R, Kool DR, Deunk J, et al. Effects on mortality, treatment, and time management as a result of routine use of total body computed tomography in blunt high-energy trauma patients. J Trauma Acute Care Surg. 2012;72(3):553Y559. 5. Sierink JC, Saltzherr TP, Reitsma JB, et al. Systematic review and meta-analysis of immediate total-body computed tomography compared with selective radiological imaging of injured patients. Br J Surg. 2012;99(Suppl 1):52Y58.
Re: Routine whole-body computed tomography in major trauma resuscitation: From ‘‘donut of death’’ to ‘‘do not without’’? In Reply: e would like to thank Drs. Narvestad and Soreide for their thoughtful and insightful editorial. We initiated this metaanalysis because we were equally frustrated (but intrigued) with the progression toward routine application of whole-body computed tomography (WBCT) or ‘‘pan-scan’’ among trauma patients. We aimed to perform a rigorous systematic review that was as inclusive as possible, and then, we had to follow the data to their logical conclusion. We completely agree that a large, wellexecuted randomized trial (that will hopefully be reported from the REACT-2 Trial) would shed a great deal of light on the value of WBCT in trauma. However, until such studies are available, we have to base decisions on the best available studies. It is surprising to criticize our meta-analysis because one study constitutes too many of the total patients. The results from more than 16,000 patients from 211 hospitals should be seen as a valuable contributionVnot as a
W
* 2015 Wolters Kluwer Health, Inc. All rights reserved.
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
