- Email: [email protected]
Predicting outcome of patients with chest wall injury
The American Journal of Surgery (2012) 204, 910 –914
The Southwestern Surgical Congress
Predicting outcome of patients with chest wall injury Crystal M. Pressley, M.D., M.P.H.c, William R. Fry, M.D.a, Allan S. Philp, M.D.a, Stepheny D. Berry, M.D.d, R. Stephen Smith, M.D.a,b,* a
West Penn Allegheny Health System, Pittsburgh, PA, USA; bUniversity of South Carolina School of Medicine, Columbia, SC, USA; cVirginia Tech Carilion School of Medicine, Roanoke, VA, USA; dUniversity of Kansas School of Medicine, Kansas City, KS, USA KEYWORDS: Rib fractures; Scoring system; Rib fixation; Mechanical ventilation
Abstract BACKGROUND: Rib fractures occur in 10% of injured patients, are associated with morbidity and mortality, and frequently necessitate intensive care unit (ICU) care. A scoring system that identifies the risk for respiratory failure early in the evaluation process may allow early intervention to improve outcomes. The aim of this study was to test the hypothesis that a scoring system based on initial clinical findings can identify patients with rib fractures at greatest risk for morbidity and mortality. METHODS: A simple scoring system to stratify risk was developed and applied to patients through a retrospective trauma registry review. Points were assigned as follows: age ⬍ 45 years ⫽ 1 point, age 45 to 65 years ⫽ 2 points, age ⬎ 65 years ⫽ 3 points; ⬍3 fractures ⫽ 1 point, 3 to 5 fractures ⫽ 2 points, ⬎5 fractures ⫽ 3 points; no pulmonary contusion ⫽ 0 points, mild pulmonary contusion ⫽ 1 point, severe pulmonary contusion ⫽ 2 points, bilateral pulmonary contusion ⫽ 3 points; and bilateral rib fracture absent ⫽ 0 points, bilateral rib fracture absent present ⫽ 2 points. A review of trauma registry patients with rib fractures (June 2008 to February 2010) at a state-designated level 1 trauma center was performed. Data reviewed included age, number of fractures, bilateral injury, presence of pulmonary contusion, classification of the contusion, length of hospital stay, mechanical ventilation, ICU admission, and length of stay. The scoring system was retrospectively applied to 649 patients to determine validity. RESULTS: A score ⱕ 7 indicated lower mortality (24 of 579 [4.2%]) compared with patients with scores ⬎ 7 (10 of 70 [14.3%]) (Fisher’s 2-sided P ⫽ .0018). Patients with scores ⱕ 6 were less likely to be admitted to an ICU (29.7%) compared with those with scores ⱖ 7 (56.7%) (P ⬍ .0001). Patients with total scores ⬍ 7 were less likely to require intubation (20.6%) compared with those with scores ⱖ 7 (40.0%) (P ⬍ .0001). Patients with scores ⱕ 4 had shorter lengths of stay (36.0% ⬍5 days) compared with those who had scores ⬎ 4 (59.7%) (P ⬍ .0001). CONCLUSIONS: A simple scoring system predicts the likelihood that patients will require mechanical ventilation and prolonged courses of care. A score of 7 or 8 predicted increased risk for mortality, admission to the ICU, and intubation. A score ⬎ 5 predicted a longer length of stay and a longer period of ventilation. This scoring system may assist in the earlier implementation of treatment strategies such epidural anesthesia, ventilation, and operative fixation of fractures. © 2012 Published by Elsevier Inc.
Presented at the annual meeting of the Southwestern Surgical Congress, Rancho Palos Verdes, CA, March 27, 2012. * Corresponding author. Tel.: 803-545-5800; fax: 803-434-6104. E-mail address: [email protected] Manuscript received March 8, 2012; revised manuscript May 21, 2012
0002-9610/$ - see front matter © 2012 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.amjsurg.2012.05.015
Rib fractures occur in ⬎10% of injured patients and are associated with significant morbidity and mortality. Mortality rates up to 25% have been documented in some series.1–3 Associated complications that frequently develop in these patients include respiratory failure secondary to altered chest wall mechanics from the fractures and respiratory
C.M. Pressley et al.
Predicting outcome of chest wall injury
distress from fracture-associated pain. Underlying pulmonary contusion plays a prominent role in the hypoxia that develops after chest wall injury. This complex pathophysiology often necessitates endotracheal intubation, prolonged mechanical ventilation, tracheostomy, and prolonged intensive care unit (ICU) length of stay.4,5 In addition, poor pulmonary function and mechanical ventilation increase the risk for the development of pneumonia, which is a frequent cause of death.1,2 Several factors have been shown to contribute to the morbidity and mortality associated with thoracic wall injury. These factors include age, the total number of fractures, and the presence of bilateral fractures. Increases in morbidity and mortality have been demonstrated in patients aged ⱖ 65 years. Patients as young as 45 years of age have been shown to have worse outcomes, depending on the severity of the injury.4,5 These differences in morbidity and mortality are due in part to the normal aging process that leads to an increased susceptibility to the occurrence of rib fractures and the development of complications. An increased number of fractures may be seen in younger patients because of mechanisms of injury associated with greater kinetic injury, while older patients’ injuries may be related to decreased bone density.4,5 Differences in the mechanics and physiology of the respiratory system as patients age include decreased oxygen exchange and a higher predisposition to developing infections. Both of these factors contribute to increased morbidity and mortality after thoracic trauma.5 Other variables related to rib fractures include the presence of pulmonary contusions, pneumothorax, hemothorax, flail segments, and bilateral rib fractures.4,5 Frequently used therapeutic modalities include pulmonary toilet, mobilization, and pain management with patient-controlled analgesia (PCA) or epidural analgesia. Adequate pain control allows deep breathing, enhanced respiratory excursion, and improved respiratory function. The use of epidural analgesia correlates with a reduction in mortality.5,6 Mechanical ventilation and early operative intervention for fixation of the fractures may also be helpful with more severe injuries.2,5– 8 Choosing the most appropriate interventions is important to minimize or prevent the complications that develop secondary to rib fractures. Optimal timing of therapeutic interventions such as thoracic epidural anesthesia can potentially prevent or decrease the need for mechanical ventilation as well as decrease the length of hospitalization required.7–10 The earlier in the patient’s course that interventions can be introduced would presumably provide the greatest benefit.6 A reliable method to predict the clinical courses of these patients on presentation has not been readily available. A scoring system that provides early identification of patients at the greatest risk for respiratory failure may allow the early institution of intervention to improve outcomes. The purpose of this study was to determine if a simple scoring system can accurately predict within the first 24 hours of care which patients are most likely to have poor outcomes and require intensive care. By association, this group of
911 Table 1
Chest wall trauma scoring system
Age (y)
Number of rib fractures
⬍45 ⫽ 1 point 45–65 ⫽ 2 points ⬎65 ⫽ 3 points Score: ___ Pulmonary contusion None ⫽ 0 points Mild ⫽ 1 point Severe ⫽ 2 points Bilateral ⫽ 3 points Score: ___ Total score: ___
⬍3 ⫽ 1 point 3–5 ⫽ 2 points ⬎5 ⫽ 3 points Score: ___ Bilateral rib fractures No ⫽ 0 points Yes ⫽ 2 points Score: ___
patients would be most likely to have favorable responses to more aggressive modes of intervention directed at improving respiratory function.
Methods This study was performed at a busy, state-designated level 1 trauma center. After obtaining approval from the institutional review board, a simple scoring system to stratify risk for patients with rib fractures was developed on the basis of currently available literature (Table 1). The scoring system was specifically formulated to use clinical data available at the time of initial patient evaluation. The validity of the scoring system was tested by retrospectively applying the system to a large group of injured patients through a review of registry data from a level 1 trauma center. The trauma registry was reviewed for patients presenting with rib fractures between June 2008 and February 2010. A total of 649 patients with complete registry information were included in this study. The scoring system was retrospectively applied to each of these patient records to determine its validity and identify total scores with predictive efficacy. Data examined from the registry included patient age; the number of rib fractures; the presence or absence of bilateral rib fractures; the presence of pulmonary contusion; classification of pulmonary contusion as mild, moderate, or severe; the need for intubation and mechanical ventilation; ICU admission; and lengths of ICU and overall hospital stays. Patients were excluded from the analysis if they expired in the emergency department or were ⬍18 years of age or if all necessary data were not available from the registry. To test for significant differences in outcomes on the basis of total score, patients were divided into 2 groups, and Fisher’s exact test was used. The groups were determined on the basis of visual assessment of the descriptive charts. For each of the 5 outcome variables, multiple groupings or cut points were assessed. If all groupings produced statistically significant results, the grouping using the lowest total score is reported here.
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The American Journal of Surgery, Vol 204, No 6, December 2012
Results Mortality Patients with total scores ⱕ 7 had a statistically significant lower mortality rate (24 of 579 [4.2%]) compared with patients with total scores ⬎ 7 (10 of 70 [14.3%]) (Fisher’s 2-sided P ⫽ .0018).
ICU admission Patients with a total scores ⱕ 6 were less likely to be admitted to an ICU (29.7%) compared with patients with total scores ⱖ 7 (56.7%) (P ⬍ .0001).
Mechanical ventilation Patients with total scores ⬍ 7 were less likely to require intubation and mechanical ventilation (20.6%) compared with those with scores ⱖ 7 (40.0%) (P ⬍ .0001).
Length of hospital stay The median length of stay for all patients was 5 days. Patients with scores ⱕ 4 had shorter lengths of stay (36.0% ⬍5 days) compared with those who had scores ⬎ 4 (59.7%) (P ⬍ .0001).
Comments Much of the respiratory insufficiency associated with chest wall injury is due to pain associated with rib fractures. Whether because of chest wall deformity or decreased respiratory effort in attempts to reduce pain with breathing, the loss of normal pulmonary function decreases gas exchange and the ability to clear secretions, increases atelectasis, and is associated with the development of pneumonia. Continued decline in respiratory effort and pulmonary function results in the need for mechanical ventilation in a significant number of patients.6 – 8 The use of intercostal nerve blocks, PCA, and epidural anesthesia have been proven to assist with pain control. When instituted early in the course of treatment, these modalities are proven to decrease the incidence of these respiratory complications.6 PCA allows patients to control the frequency of administration of narcotic analgesics by an intravenous route. However, depending on the severity of the rib fractures, chest wall muscular injury, and other associated injuries, it is often difficult to administer an effective dose of analgesics to adequately control pain. Increasing the dose of narcotics via the PCA device can potentially lead to oversedation, decreased respiratory effort, and progression to respiratory failure. Epidural anesthesia is an effective method of providing excellent analge-
Figure 1 Operative fixation of multiple rib fractures. Note extensive bony and soft tissue injuries of the chest wall after blunt trauma.
sia to patients with significant chest wall injuries. The beneficial effect of this modality is enhanced by earlier use during a patient’s postinjury plan of care.6 Obviously, not all patients with rib fractures will require epidural anesthesia, and this procedure is not without some risk. We believe that this scoring system may provide guidance in choosing the highest risk patients who will benefit most from early institution of this intervention. Previous analyses have demonstrated that treatment with epidural anesthesia enables patients to cough, breathe deeply, and more actively participate in aggressive pulmonary toilet.6 Additionally, patient mobility is improved, the ability to ambulate is promoted, and improved respiratory function results. Earlier institution of mechanical ventilation is another intervention that may improve outcomes. Intubation and mechanical ventilation provide a secure airway, improve oxygenation and ventilation, and can assist in pain control by decreasing respiratory efforts. However, the numerous complications associated with this modality include barotrauma to the lung, ventilator-associated pneumonia, the inability to clear secretions, respiratory deconditioning, and damage to the airway.8 Some investigators have advocated operative intervention with open reduction and internal fixation of rib fractures as a method to addresses respiratory dysfunction caused by pain, abnormal chest wall mechanics, and chest wall deformity (Fig. 1). Operative fixation of rib fractures has been suggested by a number of authors to be effective in liberating patients from the ventilator as well as providing significant pain relief.7–18 Unfortunately, the vast majority of this experience consists of retrospective reports and anecdotal experience. Conversely, Tanaka et al10 reported a very favorable experience with operative fixation of rib fractures in a randomized, prospective trial that compared prolonged therapy with mechanical ventilation to operative treatment after 5 days of nonoperative management. Up to this time, the decision to perform operative fixation has been
C.M. Pressley et al.
Predicting outcome of chest wall injury
based largely on subjective criteria such as surgeon gestalt or patient discomfort or on the need for prolonged periods of mechanical ventilation without progress in weaning. The present literature has not provided clear guidance on the appropriate indications or optimal timing of operative intervention. We believe that the application of this scoring system may be helpful in identifying patients, early in their clinical courses, who could benefit from this procedure. Although the results of this study indicate the ability of this scoring system to predict patient outcomes, there are shortcomings. First, this was a retrospective study, and therefore no standardized method was in place to evaluate the rib fractures. However, as trauma patients, they all underwent chest radiography, and most underwent computed tomography of the thorax. Many of these patients sustained multiple injuries, which influences outcomes. The data that were collected for this scoring system are representative of the clinical information that can be obtained on initial evaluation. This scoring system is meant to include a limited set of variables that are easily determined by standard trauma evaluation. Obviously, there are numerous other factors that potentially influence outcome, but the benefits of early identification of high-risk patients are obvious. The presence of flail chest has been shown in previous studies to influence morbidity and mortality. However, most of these studies were performed before the widespread use of computed tomography and thus included only patients with the most severe chest wall injuries detected by conventional chest radiography and physical examination. Computed tomography is a diagnostic modality with greater sensitivity, specificity, and accuracy in the detection of chest wall injury. Neither the number of catheters placed for thoracic epidural analgesia nor the duration of such analgesic interventions could be determined from this retrospective analysis. Further prospective evaluation of the scoring system should document in detail the analgesic interventions provided. This retrospective analysis found predictive value of the scoring system. However, a prospective trial is needed to further validate this scoring system and is planned as the next step. Protocol development for a prospective, multicenter trial is under way.
Conclusions A scoring system can be used to predict which patients are more likely to require mechanical ventilation and require prolonged courses of care, as well as those with a higher mortality risk. Patients with total scores ⱖ 7 are at greater risk for mortality, admission to an ICU, and mechanical ventilation. Patients with scores ⱖ 5 are more likely to experience longer lengths of stay and mechanical ventilation. The use of this scoring system may help in the immediate identification of patients who will have worse outcomes. The scoring system can assist in the
913 earlier development of treatment strategies, which may include epidural anesthesia, institution of mechanical ventilation, and operative fixation of fractures. With this scoring system, we believe that patient outcomes may be predicted on the basis of presenting injuries and that this knowledge may be used to develop treatment strategies that are most beneficial.
References 1. Brasel KJ, Guse CE, Layde P, et al. Rib fractures: relationship with pneumonia and mortality. Crit Care Med 2006;34:1642– 6. 2. Nirula R, Allen B, Layman R, et al. Rib fracture stabilization in patients sustaining blunt chest injury. Am Surg 2006;72:307–9. 3. Kent R, Woods W, Bostrom O. Fatality risk and the presence of rib fractures. Annu Proc Assoc Adv Automotiv Med 2008;52:73– 84. 4. Flagel BT, Lucette FA, Reed RL, et al. Half-a-dozen ribs: the breakpoint for mortality. Surgery 2005;138:717–23. 5. Pape H, Remmers D, Rice J, et al. Appraisal of early evaluation of blunt chest trauma: development of a standardized scoring system for initial clinical decision making. J Trauma 2000;49:496 –504. 6. Todd SR, McNally MM, Holcomb JB, et al. A multidisciplinary clinical pathway decreases rib fracture-associated infectious morbidity and mortality in high risk trauma patients. Am J Surg 2006;192:806 –11. 7. Solberg B, Moon C, Nissim A, et al. Treatment of chest wall implosion injuries without thoracotomy: technique and clinical outcomes. J Trauma 2009;87:8 –13. 8. Ahmed Z, Mohyuddin Z. Management of flail chest injury: internal fixation versus endotracheal intubation and ventilation. J Thorac Cardiovasc Surg 1995;110:1676 – 80. 9. Richardson JD, Frankling GA, Heffley S, et al. Operative fixation of chest wall fractures: an underused procedure? Am Surg 2007;73: 591–7. 10. Tanaka H, Yukioka T, Yamaguti Y, et al. Surgical stabilization of internal pneumatic stabilization? A prospective randomized study of management of severe flail chest patients. J Trauma 2002;52:727–32. 11. Collins C, Weireter L, Britt L. Surgical stabilization of severe rib fractures improves liberation from mechanical ventilation. Presented at: 70th Annual Meeting of the American Association for the Surgery of Trauma. Chicago, IL; September 16, 2011. 12. Mohr M, Abrams C, Long W. Geometry of human ribs pertinent to orthopedic chest-wall reconstruction. J Biomech 2007;40:1310 –7. 13. Balci A, Eren S, Cakir O. Open fixation in flail chest: review of 64 patients. Asian Cardiovasc Thorac Ann 2004;12:11–5. 14. Mayberry J, Terhes J, Ellis T. Absorbable plates for rib fracture repair: preliminary experience. J Trauma 2003;55:835–9. 15. Samarrai A. Costosynthetic stabilization of massive chest wall instability. Int Surg 1990;75:231–3. 16. Nirula R, Diaz JJ, Trunkey DD, et al. Rib fracture repair: indications, technical issues, and future directions World J Surg 2009;33:14 –22. 17. Engel C, Krieg J, Madey S, et al. Operative chest wall fixation with osteosynthesis plates. J Trauma 2005;58:181– 6. 18. Addor G, Monteiro A, Nigri D, et al. Trauma-related thoracoplasty: case report. J Bras Pneumol 2007;33:351– 4.
Discussion Dr Michael S. Truitt (Dallas, TX): Dr Smith et al have begun the process of doing something very important. Designing a tool that goes beyond our current rudimentary scoring system that will allow us to predict who will benefit
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from early/more aggressive intervention is essential. I applaud the authors for their work and I have the following questions: (1) Are the Injury Severity Scores (ISS) the same across each of these patient populations? Were there confounding injuries (TBI) that may have affected your data? (2) Was the presence or absence of flail chest accounted for in your scoring system? (3) Were the analgesia modalities employed across the groups similar or could this have an effect on the outcomes? Dr Crystal M. Pressley (Roanoke, VA): A few of these patients had traumatic brain injuries, but due to the retrospective nature of this study, we didn’t exclude them. We are planning a prospective trial based on this scoring system and patients with an initial GCS of less than 13 will be excluded. The scoring system did not specifically include the presence of a flail segment, but obviously, those patients with flail chest would have a higher score. Our retrospective data did not allow a meaningful analysis of the incidence or duration of epidural analgesia. Dr Truitt: I encourage you to continue developing this. We’ve discussed the need for this at the Western Trauma and now at the Southwest Surgical Congress. Our ability to predict outcomes in patients who sustain chest wall trauma is extremely simplistic and insufficient. Some patients with minimal trauma do poorly and some with significant chest wall trauma have an uneventful hospital course. This is something what we need and the systems we have used in the past have not been sophisticated enough to answer that question. I think this could be the beginning of us being able to predict those things in the future. Dr Walt Biffl (Denver, CO): Rib fracture is generally
considered one of those ho-hum injuries that trauma surgeons have to take care of. They are not very exciting, but they can be lethal. The management of them doesn’t seem too complicated on the surface. If the patient can’t breathe, you’ve got to support them; if they’ve got too much pain, you’ve got to treat the pain. I think where you could help us with this paper is to give us a scoring system that we can take for the patients, not just to tell us when we need to intubate a patient—we can figure that out. But to say you’ve got a 14% mortality based on this paper, that doesn’t really inform the discussion with a family; on the other hand, if you’ve got an 80-year-old with a score of 11, and your data shows that their mortality is 92%, that’s a different conversation. I think you can be more specific with your scoring system and really inform some of these difficult conversations in the patients who are on the ventilator, have an epidural, have rib blocks, but they are still languishing. Has it changed your practice, and if so; how has it changed your practice? Dr Pressley: Yes. The scoring system has made us more aware of the morbidity and mortality associated with this common injury pattern. We are more likely to request thoracic epidural anesthesia and certainly emphasize early and aggressive pulmonary toilet. We are also considering the earlier utilization of operative fixation for some of these fractures, but current literature does not provide much guidance. We have been involved in a couple of cases where we have actually seen early fixation liberate patients from the ventilator. That is an area that needs further investigation.
The Southwestern Surgical Congress
Predicting outcome of patients with chest wall injury Crystal M. Pressley, M.D., M.P.H.c, William R. Fry, M.D.a, Allan S. Philp, M.D.a, Stepheny D. Berry, M.D.d, R. Stephen Smith, M.D.a,b,* a
West Penn Allegheny Health System, Pittsburgh, PA, USA; bUniversity of South Carolina School of Medicine, Columbia, SC, USA; cVirginia Tech Carilion School of Medicine, Roanoke, VA, USA; dUniversity of Kansas School of Medicine, Kansas City, KS, USA KEYWORDS: Rib fractures; Scoring system; Rib fixation; Mechanical ventilation
Abstract BACKGROUND: Rib fractures occur in 10% of injured patients, are associated with morbidity and mortality, and frequently necessitate intensive care unit (ICU) care. A scoring system that identifies the risk for respiratory failure early in the evaluation process may allow early intervention to improve outcomes. The aim of this study was to test the hypothesis that a scoring system based on initial clinical findings can identify patients with rib fractures at greatest risk for morbidity and mortality. METHODS: A simple scoring system to stratify risk was developed and applied to patients through a retrospective trauma registry review. Points were assigned as follows: age ⬍ 45 years ⫽ 1 point, age 45 to 65 years ⫽ 2 points, age ⬎ 65 years ⫽ 3 points; ⬍3 fractures ⫽ 1 point, 3 to 5 fractures ⫽ 2 points, ⬎5 fractures ⫽ 3 points; no pulmonary contusion ⫽ 0 points, mild pulmonary contusion ⫽ 1 point, severe pulmonary contusion ⫽ 2 points, bilateral pulmonary contusion ⫽ 3 points; and bilateral rib fracture absent ⫽ 0 points, bilateral rib fracture absent present ⫽ 2 points. A review of trauma registry patients with rib fractures (June 2008 to February 2010) at a state-designated level 1 trauma center was performed. Data reviewed included age, number of fractures, bilateral injury, presence of pulmonary contusion, classification of the contusion, length of hospital stay, mechanical ventilation, ICU admission, and length of stay. The scoring system was retrospectively applied to 649 patients to determine validity. RESULTS: A score ⱕ 7 indicated lower mortality (24 of 579 [4.2%]) compared with patients with scores ⬎ 7 (10 of 70 [14.3%]) (Fisher’s 2-sided P ⫽ .0018). Patients with scores ⱕ 6 were less likely to be admitted to an ICU (29.7%) compared with those with scores ⱖ 7 (56.7%) (P ⬍ .0001). Patients with total scores ⬍ 7 were less likely to require intubation (20.6%) compared with those with scores ⱖ 7 (40.0%) (P ⬍ .0001). Patients with scores ⱕ 4 had shorter lengths of stay (36.0% ⬍5 days) compared with those who had scores ⬎ 4 (59.7%) (P ⬍ .0001). CONCLUSIONS: A simple scoring system predicts the likelihood that patients will require mechanical ventilation and prolonged courses of care. A score of 7 or 8 predicted increased risk for mortality, admission to the ICU, and intubation. A score ⬎ 5 predicted a longer length of stay and a longer period of ventilation. This scoring system may assist in the earlier implementation of treatment strategies such epidural anesthesia, ventilation, and operative fixation of fractures. © 2012 Published by Elsevier Inc.
Presented at the annual meeting of the Southwestern Surgical Congress, Rancho Palos Verdes, CA, March 27, 2012. * Corresponding author. Tel.: 803-545-5800; fax: 803-434-6104. E-mail address: [email protected] Manuscript received March 8, 2012; revised manuscript May 21, 2012
0002-9610/$ - see front matter © 2012 Published by Elsevier Inc. http://dx.doi.org/10.1016/j.amjsurg.2012.05.015
Rib fractures occur in ⬎10% of injured patients and are associated with significant morbidity and mortality. Mortality rates up to 25% have been documented in some series.1–3 Associated complications that frequently develop in these patients include respiratory failure secondary to altered chest wall mechanics from the fractures and respiratory
C.M. Pressley et al.
Predicting outcome of chest wall injury
distress from fracture-associated pain. Underlying pulmonary contusion plays a prominent role in the hypoxia that develops after chest wall injury. This complex pathophysiology often necessitates endotracheal intubation, prolonged mechanical ventilation, tracheostomy, and prolonged intensive care unit (ICU) length of stay.4,5 In addition, poor pulmonary function and mechanical ventilation increase the risk for the development of pneumonia, which is a frequent cause of death.1,2 Several factors have been shown to contribute to the morbidity and mortality associated with thoracic wall injury. These factors include age, the total number of fractures, and the presence of bilateral fractures. Increases in morbidity and mortality have been demonstrated in patients aged ⱖ 65 years. Patients as young as 45 years of age have been shown to have worse outcomes, depending on the severity of the injury.4,5 These differences in morbidity and mortality are due in part to the normal aging process that leads to an increased susceptibility to the occurrence of rib fractures and the development of complications. An increased number of fractures may be seen in younger patients because of mechanisms of injury associated with greater kinetic injury, while older patients’ injuries may be related to decreased bone density.4,5 Differences in the mechanics and physiology of the respiratory system as patients age include decreased oxygen exchange and a higher predisposition to developing infections. Both of these factors contribute to increased morbidity and mortality after thoracic trauma.5 Other variables related to rib fractures include the presence of pulmonary contusions, pneumothorax, hemothorax, flail segments, and bilateral rib fractures.4,5 Frequently used therapeutic modalities include pulmonary toilet, mobilization, and pain management with patient-controlled analgesia (PCA) or epidural analgesia. Adequate pain control allows deep breathing, enhanced respiratory excursion, and improved respiratory function. The use of epidural analgesia correlates with a reduction in mortality.5,6 Mechanical ventilation and early operative intervention for fixation of the fractures may also be helpful with more severe injuries.2,5– 8 Choosing the most appropriate interventions is important to minimize or prevent the complications that develop secondary to rib fractures. Optimal timing of therapeutic interventions such as thoracic epidural anesthesia can potentially prevent or decrease the need for mechanical ventilation as well as decrease the length of hospitalization required.7–10 The earlier in the patient’s course that interventions can be introduced would presumably provide the greatest benefit.6 A reliable method to predict the clinical courses of these patients on presentation has not been readily available. A scoring system that provides early identification of patients at the greatest risk for respiratory failure may allow the early institution of intervention to improve outcomes. The purpose of this study was to determine if a simple scoring system can accurately predict within the first 24 hours of care which patients are most likely to have poor outcomes and require intensive care. By association, this group of
911 Table 1
Chest wall trauma scoring system
Age (y)
Number of rib fractures
⬍45 ⫽ 1 point 45–65 ⫽ 2 points ⬎65 ⫽ 3 points Score: ___ Pulmonary contusion None ⫽ 0 points Mild ⫽ 1 point Severe ⫽ 2 points Bilateral ⫽ 3 points Score: ___ Total score: ___
⬍3 ⫽ 1 point 3–5 ⫽ 2 points ⬎5 ⫽ 3 points Score: ___ Bilateral rib fractures No ⫽ 0 points Yes ⫽ 2 points Score: ___
patients would be most likely to have favorable responses to more aggressive modes of intervention directed at improving respiratory function.
Methods This study was performed at a busy, state-designated level 1 trauma center. After obtaining approval from the institutional review board, a simple scoring system to stratify risk for patients with rib fractures was developed on the basis of currently available literature (Table 1). The scoring system was specifically formulated to use clinical data available at the time of initial patient evaluation. The validity of the scoring system was tested by retrospectively applying the system to a large group of injured patients through a review of registry data from a level 1 trauma center. The trauma registry was reviewed for patients presenting with rib fractures between June 2008 and February 2010. A total of 649 patients with complete registry information were included in this study. The scoring system was retrospectively applied to each of these patient records to determine its validity and identify total scores with predictive efficacy. Data examined from the registry included patient age; the number of rib fractures; the presence or absence of bilateral rib fractures; the presence of pulmonary contusion; classification of pulmonary contusion as mild, moderate, or severe; the need for intubation and mechanical ventilation; ICU admission; and lengths of ICU and overall hospital stays. Patients were excluded from the analysis if they expired in the emergency department or were ⬍18 years of age or if all necessary data were not available from the registry. To test for significant differences in outcomes on the basis of total score, patients were divided into 2 groups, and Fisher’s exact test was used. The groups were determined on the basis of visual assessment of the descriptive charts. For each of the 5 outcome variables, multiple groupings or cut points were assessed. If all groupings produced statistically significant results, the grouping using the lowest total score is reported here.
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The American Journal of Surgery, Vol 204, No 6, December 2012
Results Mortality Patients with total scores ⱕ 7 had a statistically significant lower mortality rate (24 of 579 [4.2%]) compared with patients with total scores ⬎ 7 (10 of 70 [14.3%]) (Fisher’s 2-sided P ⫽ .0018).
ICU admission Patients with a total scores ⱕ 6 were less likely to be admitted to an ICU (29.7%) compared with patients with total scores ⱖ 7 (56.7%) (P ⬍ .0001).
Mechanical ventilation Patients with total scores ⬍ 7 were less likely to require intubation and mechanical ventilation (20.6%) compared with those with scores ⱖ 7 (40.0%) (P ⬍ .0001).
Length of hospital stay The median length of stay for all patients was 5 days. Patients with scores ⱕ 4 had shorter lengths of stay (36.0% ⬍5 days) compared with those who had scores ⬎ 4 (59.7%) (P ⬍ .0001).
Comments Much of the respiratory insufficiency associated with chest wall injury is due to pain associated with rib fractures. Whether because of chest wall deformity or decreased respiratory effort in attempts to reduce pain with breathing, the loss of normal pulmonary function decreases gas exchange and the ability to clear secretions, increases atelectasis, and is associated with the development of pneumonia. Continued decline in respiratory effort and pulmonary function results in the need for mechanical ventilation in a significant number of patients.6 – 8 The use of intercostal nerve blocks, PCA, and epidural anesthesia have been proven to assist with pain control. When instituted early in the course of treatment, these modalities are proven to decrease the incidence of these respiratory complications.6 PCA allows patients to control the frequency of administration of narcotic analgesics by an intravenous route. However, depending on the severity of the rib fractures, chest wall muscular injury, and other associated injuries, it is often difficult to administer an effective dose of analgesics to adequately control pain. Increasing the dose of narcotics via the PCA device can potentially lead to oversedation, decreased respiratory effort, and progression to respiratory failure. Epidural anesthesia is an effective method of providing excellent analge-
Figure 1 Operative fixation of multiple rib fractures. Note extensive bony and soft tissue injuries of the chest wall after blunt trauma.
sia to patients with significant chest wall injuries. The beneficial effect of this modality is enhanced by earlier use during a patient’s postinjury plan of care.6 Obviously, not all patients with rib fractures will require epidural anesthesia, and this procedure is not without some risk. We believe that this scoring system may provide guidance in choosing the highest risk patients who will benefit most from early institution of this intervention. Previous analyses have demonstrated that treatment with epidural anesthesia enables patients to cough, breathe deeply, and more actively participate in aggressive pulmonary toilet.6 Additionally, patient mobility is improved, the ability to ambulate is promoted, and improved respiratory function results. Earlier institution of mechanical ventilation is another intervention that may improve outcomes. Intubation and mechanical ventilation provide a secure airway, improve oxygenation and ventilation, and can assist in pain control by decreasing respiratory efforts. However, the numerous complications associated with this modality include barotrauma to the lung, ventilator-associated pneumonia, the inability to clear secretions, respiratory deconditioning, and damage to the airway.8 Some investigators have advocated operative intervention with open reduction and internal fixation of rib fractures as a method to addresses respiratory dysfunction caused by pain, abnormal chest wall mechanics, and chest wall deformity (Fig. 1). Operative fixation of rib fractures has been suggested by a number of authors to be effective in liberating patients from the ventilator as well as providing significant pain relief.7–18 Unfortunately, the vast majority of this experience consists of retrospective reports and anecdotal experience. Conversely, Tanaka et al10 reported a very favorable experience with operative fixation of rib fractures in a randomized, prospective trial that compared prolonged therapy with mechanical ventilation to operative treatment after 5 days of nonoperative management. Up to this time, the decision to perform operative fixation has been
C.M. Pressley et al.
Predicting outcome of chest wall injury
based largely on subjective criteria such as surgeon gestalt or patient discomfort or on the need for prolonged periods of mechanical ventilation without progress in weaning. The present literature has not provided clear guidance on the appropriate indications or optimal timing of operative intervention. We believe that the application of this scoring system may be helpful in identifying patients, early in their clinical courses, who could benefit from this procedure. Although the results of this study indicate the ability of this scoring system to predict patient outcomes, there are shortcomings. First, this was a retrospective study, and therefore no standardized method was in place to evaluate the rib fractures. However, as trauma patients, they all underwent chest radiography, and most underwent computed tomography of the thorax. Many of these patients sustained multiple injuries, which influences outcomes. The data that were collected for this scoring system are representative of the clinical information that can be obtained on initial evaluation. This scoring system is meant to include a limited set of variables that are easily determined by standard trauma evaluation. Obviously, there are numerous other factors that potentially influence outcome, but the benefits of early identification of high-risk patients are obvious. The presence of flail chest has been shown in previous studies to influence morbidity and mortality. However, most of these studies were performed before the widespread use of computed tomography and thus included only patients with the most severe chest wall injuries detected by conventional chest radiography and physical examination. Computed tomography is a diagnostic modality with greater sensitivity, specificity, and accuracy in the detection of chest wall injury. Neither the number of catheters placed for thoracic epidural analgesia nor the duration of such analgesic interventions could be determined from this retrospective analysis. Further prospective evaluation of the scoring system should document in detail the analgesic interventions provided. This retrospective analysis found predictive value of the scoring system. However, a prospective trial is needed to further validate this scoring system and is planned as the next step. Protocol development for a prospective, multicenter trial is under way.
Conclusions A scoring system can be used to predict which patients are more likely to require mechanical ventilation and require prolonged courses of care, as well as those with a higher mortality risk. Patients with total scores ⱖ 7 are at greater risk for mortality, admission to an ICU, and mechanical ventilation. Patients with scores ⱖ 5 are more likely to experience longer lengths of stay and mechanical ventilation. The use of this scoring system may help in the immediate identification of patients who will have worse outcomes. The scoring system can assist in the
913 earlier development of treatment strategies, which may include epidural anesthesia, institution of mechanical ventilation, and operative fixation of fractures. With this scoring system, we believe that patient outcomes may be predicted on the basis of presenting injuries and that this knowledge may be used to develop treatment strategies that are most beneficial.
References 1. Brasel KJ, Guse CE, Layde P, et al. Rib fractures: relationship with pneumonia and mortality. Crit Care Med 2006;34:1642– 6. 2. Nirula R, Allen B, Layman R, et al. Rib fracture stabilization in patients sustaining blunt chest injury. Am Surg 2006;72:307–9. 3. Kent R, Woods W, Bostrom O. Fatality risk and the presence of rib fractures. Annu Proc Assoc Adv Automotiv Med 2008;52:73– 84. 4. Flagel BT, Lucette FA, Reed RL, et al. Half-a-dozen ribs: the breakpoint for mortality. Surgery 2005;138:717–23. 5. Pape H, Remmers D, Rice J, et al. Appraisal of early evaluation of blunt chest trauma: development of a standardized scoring system for initial clinical decision making. J Trauma 2000;49:496 –504. 6. Todd SR, McNally MM, Holcomb JB, et al. A multidisciplinary clinical pathway decreases rib fracture-associated infectious morbidity and mortality in high risk trauma patients. Am J Surg 2006;192:806 –11. 7. Solberg B, Moon C, Nissim A, et al. Treatment of chest wall implosion injuries without thoracotomy: technique and clinical outcomes. J Trauma 2009;87:8 –13. 8. Ahmed Z, Mohyuddin Z. Management of flail chest injury: internal fixation versus endotracheal intubation and ventilation. J Thorac Cardiovasc Surg 1995;110:1676 – 80. 9. Richardson JD, Frankling GA, Heffley S, et al. Operative fixation of chest wall fractures: an underused procedure? Am Surg 2007;73: 591–7. 10. Tanaka H, Yukioka T, Yamaguti Y, et al. Surgical stabilization of internal pneumatic stabilization? A prospective randomized study of management of severe flail chest patients. J Trauma 2002;52:727–32. 11. Collins C, Weireter L, Britt L. Surgical stabilization of severe rib fractures improves liberation from mechanical ventilation. Presented at: 70th Annual Meeting of the American Association for the Surgery of Trauma. Chicago, IL; September 16, 2011. 12. Mohr M, Abrams C, Long W. Geometry of human ribs pertinent to orthopedic chest-wall reconstruction. J Biomech 2007;40:1310 –7. 13. Balci A, Eren S, Cakir O. Open fixation in flail chest: review of 64 patients. Asian Cardiovasc Thorac Ann 2004;12:11–5. 14. Mayberry J, Terhes J, Ellis T. Absorbable plates for rib fracture repair: preliminary experience. J Trauma 2003;55:835–9. 15. Samarrai A. Costosynthetic stabilization of massive chest wall instability. Int Surg 1990;75:231–3. 16. Nirula R, Diaz JJ, Trunkey DD, et al. Rib fracture repair: indications, technical issues, and future directions World J Surg 2009;33:14 –22. 17. Engel C, Krieg J, Madey S, et al. Operative chest wall fixation with osteosynthesis plates. J Trauma 2005;58:181– 6. 18. Addor G, Monteiro A, Nigri D, et al. Trauma-related thoracoplasty: case report. J Bras Pneumol 2007;33:351– 4.
Discussion Dr Michael S. Truitt (Dallas, TX): Dr Smith et al have begun the process of doing something very important. Designing a tool that goes beyond our current rudimentary scoring system that will allow us to predict who will benefit
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from early/more aggressive intervention is essential. I applaud the authors for their work and I have the following questions: (1) Are the Injury Severity Scores (ISS) the same across each of these patient populations? Were there confounding injuries (TBI) that may have affected your data? (2) Was the presence or absence of flail chest accounted for in your scoring system? (3) Were the analgesia modalities employed across the groups similar or could this have an effect on the outcomes? Dr Crystal M. Pressley (Roanoke, VA): A few of these patients had traumatic brain injuries, but due to the retrospective nature of this study, we didn’t exclude them. We are planning a prospective trial based on this scoring system and patients with an initial GCS of less than 13 will be excluded. The scoring system did not specifically include the presence of a flail segment, but obviously, those patients with flail chest would have a higher score. Our retrospective data did not allow a meaningful analysis of the incidence or duration of epidural analgesia. Dr Truitt: I encourage you to continue developing this. We’ve discussed the need for this at the Western Trauma and now at the Southwest Surgical Congress. Our ability to predict outcomes in patients who sustain chest wall trauma is extremely simplistic and insufficient. Some patients with minimal trauma do poorly and some with significant chest wall trauma have an uneventful hospital course. This is something what we need and the systems we have used in the past have not been sophisticated enough to answer that question. I think this could be the beginning of us being able to predict those things in the future. Dr Walt Biffl (Denver, CO): Rib fracture is generally
considered one of those ho-hum injuries that trauma surgeons have to take care of. They are not very exciting, but they can be lethal. The management of them doesn’t seem too complicated on the surface. If the patient can’t breathe, you’ve got to support them; if they’ve got too much pain, you’ve got to treat the pain. I think where you could help us with this paper is to give us a scoring system that we can take for the patients, not just to tell us when we need to intubate a patient—we can figure that out. But to say you’ve got a 14% mortality based on this paper, that doesn’t really inform the discussion with a family; on the other hand, if you’ve got an 80-year-old with a score of 11, and your data shows that their mortality is 92%, that’s a different conversation. I think you can be more specific with your scoring system and really inform some of these difficult conversations in the patients who are on the ventilator, have an epidural, have rib blocks, but they are still languishing. Has it changed your practice, and if so; how has it changed your practice? Dr Pressley: Yes. The scoring system has made us more aware of the morbidity and mortality associated with this common injury pattern. We are more likely to request thoracic epidural anesthesia and certainly emphasize early and aggressive pulmonary toilet. We are also considering the earlier utilization of operative fixation for some of these fractures, but current literature does not provide much guidance. We have been involved in a couple of cases where we have actually seen early fixation liberate patients from the ventilator. That is an area that needs further investigation.