Abstracts from the First Annual Baylor Scott and White Surgery Research Day
The First Annual Baylor Scott and White Surgery Research Day was held on May 2, 2014, in Temple, Texas. The program built on the tradition of eight previous research days for the Texas A&M Health Science Center College of Medicine and Scott & White Memorial Hospital and this year included the Department of Surgery at Baylor University Medical Center at Dallas. The forum is open to all Baylor Scott and White surgery fellows, residents, and medical students and includes a variety of basic science, clinical, and educational research projects with a focus on trainees’ research. The 2014 forum was organized by Dr. J. Scott Thomas and Dr. Raman C. Mahabir, under the guidance of Dr. Harry T. Papaconstantinou. This article highlights the top 16 abstracts selected from the submissions for presentation from the podium.
Cirrhosis and operative trauma: determining when care is futile Claire Isbell,∗ Mira Ghneim, Matthew Davis, Marc DeMoya, Terence O’Keeffe, Kenji Inaba, and Stephen Cohn (e-mail: [email protected]) The trauma patient with cirrhosis remains one of the most difficult to manage: mortality is high and tremendous resources are consumed, as no good metrics exist to determine futility. We sought to study cirrhotic trauma patients to establish accurate predictors of futile care. We conducted a multicenter chart review from 2001 to 2011 to identify patients with cirrhosis confirmed during trauma laparotomy. Demographic, vital sign, and laboratory data at the time of admission and operation and at 6, 24, and 48 hours postoperatively were recorded. Five centers contributed a total of 65 patients to our exploratory analysis. The median age was 49 (interquartile range [IQR] 44–56) with 94% (61/66) being male. Mortality was 47% (31/66), with a median admission Injury Severity Score of 20 (IQR 9–27). Admission vital signs (heart rate and systolic blood pressure) were not statistically different between the patients who lived and those who died. The Model for End-Stage Liver Disease score was 10 (IQR 8–11) in survivors compared to 12 (10–16) in those who died (P < 0.01). However, packed red blood cell consumption was significantly greater at 6 (10 vs 2 units), 24 (12 vs 3 units), and 48 (11 vs 4 units) hours in cirrhotic patients who died compared to those who lived. In fact, no patient who received >17 units of blood in the first 6 hours or >24 units of blood in the first 24 hours survived. The median time to death was 5 days (IQR 0–26 days). In conclusion, admission vital signs cannot be used to determine futility in a cirrhotic trauma patient who needs laparotomy. However, transfusion of >17 units of blood in the first 6 hours appears to be highly predictive of mortality in these patients. Proc (Bayl Univ Med Cent) 2014;27(4):315–320
A comparison of the Injury Severity Score and the Trauma Mortality Prediction Model Jo Weddle,∗ Alan Cook, Susan Baker, David Hosmer, Laurent Glance, Lee Friedman, and Turner Osler (e-mail: [email protected]) Performance benchmarking requires accurate measurement of injury severity. Despite its shortcomings, the Injury Severity Score (ISS) remains the industry standard 40 years after its creation. A new severity measure, the Trauma Mortality Prediction Model (TMPM), uses either the Abbreviated Injury Scale (AIS) or International Classification of Diseases (ICD)-9 lexicons and may quantify injury severity better than ISS. We compared the performance of TMPM to ISS and other measures of injury severity in a single cohort of patients. We included 337,359 patient records with injuries reliably described in both the AIS and ICD-9 lexicons from the National Trauma Data Bank. Five injury severity measures (ISS, Max AIS, New Injury Severity Score [NISS], ICD-derived Injury Severity Score [ICISS], and TMPM) were computed using either the AIS or ICD-9 codes. These measures were compared for discrimination (area under the receiver operator characteristic curve [ROC]), an estimate of proximity to a model that perfectly predicts the outcome (Akaike information criterion [AIC]), and model calibration curves. TMPM demonstrated superior ROC, AIC, and calibration using either the AIS or ICD-9 lexicons. Calibration plots demonstrated the monotonic characteristics of the TMPM models contrasted by the nonmonotonic features of the other prediction models. Severity measures were more accurate with the AIS than with the ICD-9 lexicon. NISS proved superior to ISS in either lexicon. Since NISS is simpler to compute, it should replace ISS when a quick estimate of injury severity is required for AIS-coded injuries. Calibration curves suggest that the nonmonotonic nature of ISS may undermine its performance. TMPM demonstrated superior overall mortality prediction compared to all other models, including ISS, whether the AIS or ICD-9 lexicons were used. Because TMPM provides an absolute probability of death, it may allow clinicians to communicate more precisely with one another and with patients and families.
Prevalence of brachial plexus injuries in patients with scapular fractures: a National Trauma Data Bank review Edward Chamata,∗ Raman Mahabir, and Robert Weber (e-mail: [email protected]) Literature investigating the prevalence of brachial plexus injuries associated with scapular fractures is sparse, frequently limited by small sample sizes and often restricted to one center’s experience. The purposes of this study were to find the prevalence of brachial plexus injuries associated with scapular fractures, to determine how the 315
prevalence varies with the region of the scapula injured, and to assess which specific nerves of the brachial plexus were involved. The data set of the National Trauma Data Bank was retrospectively reviewed for the 5-year period of 2007 to 2011. Of 68,118 patients with scapular fractures identified during this period, brachial plexus injury was present in 1173, or 1.72%. In patients with multiple scapular fractures, the prevalence of brachial plexus injury was 3.12%, and the prevalence ranged from 1.52% to 2.22% in patients with single scapular fractures, depending on the specific anatomic location of the fracture. Of the 426 injuries with detailed information on the nerve injury, there were 208 (49%) radial nerve injuries, 113 (26.5%) ulnar nerve injuries, 65 (15%) median nerve injuries, 36 (8.5%) axillary nerve injuries, and 4 (1%) musculocutaneous nerve injuries. In conclusion, the prevalence of brachial plexus injuries in patients with scapular fractures was 1.72%. The prevalence was similar across anatomical regions for single scapular fracture and was higher with multiple fractures. The radial nerve accounted for the largest percentage of nerve injuries.
Accuracy of clinical evaluation of orbital floor defects James Goggin,∗ Marcin Czerwinski, and Daniel Jupiter (e-mail: [email protected]) Orbital floor (OF) fractures are common in facial trauma. Repair of traumatic OF defects ≥2 cm2 is critical to prevent significant enophthalmos. A formula to precisely calculate OF defect size has been reported but is cumbersome for routine clinical use. Thus, surgeons may inaccurately rely on estimated calculations or clinical impressions to determine if repair is necessary. This study’s objective was to evaluate the accuracy of simple, rapid methods of defect size estimation and determine if any are suitable for clinical use. Following power analysis, 99 patients with OF fractures in a single regional level I trauma center were identified. True OF defect sizes were calculated using a previously validated formula, based on measurements obtained from coronally reformatted thin (65 years old. Exclusion criteria included Glasgow Coma Score
The First Annual Baylor Scott and White Surgery Research Day was held on May 2, 2014, in Temple, Texas. The program built on the tradition of eight previous research days for the Texas A&M Health Science Center College of Medicine and Scott & White Memorial Hospital and this year included the Department of Surgery at Baylor University Medical Center at Dallas. The forum is open to all Baylor Scott and White surgery fellows, residents, and medical students and includes a variety of basic science, clinical, and educational research projects with a focus on trainees’ research. The 2014 forum was organized by Dr. J. Scott Thomas and Dr. Raman C. Mahabir, under the guidance of Dr. Harry T. Papaconstantinou. This article highlights the top 16 abstracts selected from the submissions for presentation from the podium.
Cirrhosis and operative trauma: determining when care is futile Claire Isbell,∗ Mira Ghneim, Matthew Davis, Marc DeMoya, Terence O’Keeffe, Kenji Inaba, and Stephen Cohn (e-mail: [email protected]) The trauma patient with cirrhosis remains one of the most difficult to manage: mortality is high and tremendous resources are consumed, as no good metrics exist to determine futility. We sought to study cirrhotic trauma patients to establish accurate predictors of futile care. We conducted a multicenter chart review from 2001 to 2011 to identify patients with cirrhosis confirmed during trauma laparotomy. Demographic, vital sign, and laboratory data at the time of admission and operation and at 6, 24, and 48 hours postoperatively were recorded. Five centers contributed a total of 65 patients to our exploratory analysis. The median age was 49 (interquartile range [IQR] 44–56) with 94% (61/66) being male. Mortality was 47% (31/66), with a median admission Injury Severity Score of 20 (IQR 9–27). Admission vital signs (heart rate and systolic blood pressure) were not statistically different between the patients who lived and those who died. The Model for End-Stage Liver Disease score was 10 (IQR 8–11) in survivors compared to 12 (10–16) in those who died (P < 0.01). However, packed red blood cell consumption was significantly greater at 6 (10 vs 2 units), 24 (12 vs 3 units), and 48 (11 vs 4 units) hours in cirrhotic patients who died compared to those who lived. In fact, no patient who received >17 units of blood in the first 6 hours or >24 units of blood in the first 24 hours survived. The median time to death was 5 days (IQR 0–26 days). In conclusion, admission vital signs cannot be used to determine futility in a cirrhotic trauma patient who needs laparotomy. However, transfusion of >17 units of blood in the first 6 hours appears to be highly predictive of mortality in these patients. Proc (Bayl Univ Med Cent) 2014;27(4):315–320
A comparison of the Injury Severity Score and the Trauma Mortality Prediction Model Jo Weddle,∗ Alan Cook, Susan Baker, David Hosmer, Laurent Glance, Lee Friedman, and Turner Osler (e-mail: [email protected]) Performance benchmarking requires accurate measurement of injury severity. Despite its shortcomings, the Injury Severity Score (ISS) remains the industry standard 40 years after its creation. A new severity measure, the Trauma Mortality Prediction Model (TMPM), uses either the Abbreviated Injury Scale (AIS) or International Classification of Diseases (ICD)-9 lexicons and may quantify injury severity better than ISS. We compared the performance of TMPM to ISS and other measures of injury severity in a single cohort of patients. We included 337,359 patient records with injuries reliably described in both the AIS and ICD-9 lexicons from the National Trauma Data Bank. Five injury severity measures (ISS, Max AIS, New Injury Severity Score [NISS], ICD-derived Injury Severity Score [ICISS], and TMPM) were computed using either the AIS or ICD-9 codes. These measures were compared for discrimination (area under the receiver operator characteristic curve [ROC]), an estimate of proximity to a model that perfectly predicts the outcome (Akaike information criterion [AIC]), and model calibration curves. TMPM demonstrated superior ROC, AIC, and calibration using either the AIS or ICD-9 lexicons. Calibration plots demonstrated the monotonic characteristics of the TMPM models contrasted by the nonmonotonic features of the other prediction models. Severity measures were more accurate with the AIS than with the ICD-9 lexicon. NISS proved superior to ISS in either lexicon. Since NISS is simpler to compute, it should replace ISS when a quick estimate of injury severity is required for AIS-coded injuries. Calibration curves suggest that the nonmonotonic nature of ISS may undermine its performance. TMPM demonstrated superior overall mortality prediction compared to all other models, including ISS, whether the AIS or ICD-9 lexicons were used. Because TMPM provides an absolute probability of death, it may allow clinicians to communicate more precisely with one another and with patients and families.
Prevalence of brachial plexus injuries in patients with scapular fractures: a National Trauma Data Bank review Edward Chamata,∗ Raman Mahabir, and Robert Weber (e-mail: [email protected]) Literature investigating the prevalence of brachial plexus injuries associated with scapular fractures is sparse, frequently limited by small sample sizes and often restricted to one center’s experience. The purposes of this study were to find the prevalence of brachial plexus injuries associated with scapular fractures, to determine how the 315
prevalence varies with the region of the scapula injured, and to assess which specific nerves of the brachial plexus were involved. The data set of the National Trauma Data Bank was retrospectively reviewed for the 5-year period of 2007 to 2011. Of 68,118 patients with scapular fractures identified during this period, brachial plexus injury was present in 1173, or 1.72%. In patients with multiple scapular fractures, the prevalence of brachial plexus injury was 3.12%, and the prevalence ranged from 1.52% to 2.22% in patients with single scapular fractures, depending on the specific anatomic location of the fracture. Of the 426 injuries with detailed information on the nerve injury, there were 208 (49%) radial nerve injuries, 113 (26.5%) ulnar nerve injuries, 65 (15%) median nerve injuries, 36 (8.5%) axillary nerve injuries, and 4 (1%) musculocutaneous nerve injuries. In conclusion, the prevalence of brachial plexus injuries in patients with scapular fractures was 1.72%. The prevalence was similar across anatomical regions for single scapular fracture and was higher with multiple fractures. The radial nerve accounted for the largest percentage of nerve injuries.
Accuracy of clinical evaluation of orbital floor defects James Goggin,∗ Marcin Czerwinski, and Daniel Jupiter (e-mail: [email protected]) Orbital floor (OF) fractures are common in facial trauma. Repair of traumatic OF defects ≥2 cm2 is critical to prevent significant enophthalmos. A formula to precisely calculate OF defect size has been reported but is cumbersome for routine clinical use. Thus, surgeons may inaccurately rely on estimated calculations or clinical impressions to determine if repair is necessary. This study’s objective was to evaluate the accuracy of simple, rapid methods of defect size estimation and determine if any are suitable for clinical use. Following power analysis, 99 patients with OF fractures in a single regional level I trauma center were identified. True OF defect sizes were calculated using a previously validated formula, based on measurements obtained from coronally reformatted thin (65 years old. Exclusion criteria included Glasgow Coma Score
