ORIGINAL ARTICLE. Predictors of Bleeding From Stable Pelvic Fractures

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1 ONLINE FIRST ORIGINAL ARTILE Predictors of leeding From Stable Pelvic Fractures Athanasios ramos, MD; George. Velmahos, MD, PhD; Umar M. utt, MD; Karim Fikry, MD; R. Malcolm Smith, MD; Yuchiao hang, PhD Hypothesis: Stable pelvic fractures (SPFs) that do not need operative fixation are only infrequently associated with significant bleeding (Sigleed). Our hypothesis is that simple indicators, easily detectable at the bedside, can alert the clinician about the likelihood of bleeding and the need for closer monitoring or early intervention in patients with SPFs. Design: Retrospective review of medical records. Setting: Academic level 1 trauma center. Patients: The medical records of patients with SPFs admitted to our academic level 1 trauma center from January 1, 2002, to June 30, 2007, were reviewed. Stable pelvic fractures were defined as fractures not requiring external or internal fixation. Sigleed was defined as the need for blood transfusion and/or intervention for bleeding control within the first 24 hours after admission. The patients were divided into group A, which included patients without Sigleed; group, which included patients with Sigleed of a nonpelvic cause; and group, which included patients with Sigleed caused by the SPF. The 3 groups were compared by univariate and multivariate analysis. Main Outcome Measure: Significant bleeding from SPFs. Results: Of 391 patients with SPFs, 280 (72%) were in group A, 90 (23%) were in group, and 21 (5%) were in group. ompared with group A patients, those in group were older and had a lower hematocrit and systolic blood pressure on admission. They also had longer hospital stays and a higher mortality. The following independent predictors of Sigleed from SPF were identified: hematocrit of 30% or lower (odds ratio [OR], 43.93; 95% confidence interval [I], ; P.001); presence of pelvic hematoma on computed tomographic scan (OR, 39.37; 95% I, ; P.001); and systolic blood pressure of 90 mm Hg or lower (OR, ; 95% I, ; P=.01). When all independent predictors were present, 100% of the patients had Sigleed; when all were absent, no one had Sigleed. onclusions: The incidence of Sigleed due to SPFs is low (5% in this study) and independently predicted by an admission hematocrit of 30% or lower, the presence of a pelvic hematoma on computed tomographic scan, and systolic blood pressure of 90 mm Hg or lower. Arch Surg. 2011;146(4): Published online December 20, doi: /archsurg Author Affiliations: Divisions of Trauma, Emergency Surgery, and Surgical ritical are (Drs ramos, Velmahos, utt, and Fikry), Orthopedic Trauma (Dr Smith), and linical Epidemiology (Dr hang), Massachusetts General Hospital and Harvard Medical School, oston. MAJOR PELVI FRAtures after trauma are often associated with bleeding, intra-abdominal injuries, and death. 1 The overall mortality from pelvic fractures depends on the associated injuries and ranges from 5% to 14%. 2-4 Severe hemorrhage from the disrupted venous and arterial vessels near the fractured structures accounts for the early mortality, although a direct association between the pelvic bleeding and death is hard to draw if multiple injuries are present. 4,5 Several predictors, including fracture type, patient age, hemodynamic parameters, and laboratory values, have been described to identify those patients who may benefit from early angiography and embolization. 6,7 Stable pelvic fractures (SPFs) do not usually cause significant pelvic bleeding. Only case reports have been published on this issue. 8,9 The objective of this study was to identify the rate and predictors of bleeding among patients with SPFs. Our hypothesis is that these uncommon scenarios can be predicted on the basis of simple indicators, resulting in close monitoring or early intervention. METHODS Patients with SPFs who were admitted to the level 1 academic trauma center at Massachusetts General Hospital, oston, between January 1, 2002, and June 30, 2007, were retrospectively identified through our trauma registry. The SPFs were defined as fractures not 407

2 Group A 280 Patients did not receive transfusion 465 Patients with stable pelvic fractures Group 90 Patients with bleeding due to nonpelvic injury 111 Patients received transfusion 74 Patients were excluded Group 21 Patients with bleeding due to pelvic injury requiring external or internal fixation. Significant bleeding (Sigleed) was defined as the need for blood transfusion and/or intervention for bleeding control within the first 24 hours after admission. The following categories of patients were excluded from the analysis: (1) patients with unstable pelvic fractures who needed operative stabilization but died before this was achieved; (2) patients without a computed tomographic (T) scan of the pelvis because we were unable to characterize their fractures accurately and appreciate the extent of a pelvic hematoma; and (3) patients without pelvic or other sources of bleeding who received a blood transfusion for reasons clearly related to a chronic medical condition, such as anemia or chronic renal failure. The outcome of the study was Sigleed caused by SPFs. We collected data on demographics; mechanism of injury; injury severity score; 6 abbreviated injury scores; admission systolic blood pressure (SP); heart rate; Glasgow oma Scale; admission hematocrit (Hct); units of packed red blood cells; freshfrozen plasma transfused during the first 24 hours after admission; T scan findings; angiography and embolization; hospital length of stay; intensive care unit (IU) length of stay; and mortality. ecause of the retrospective nature of our study, we could not evaluate the vectors of force causing the pelvic fracture and thus used the Tile classification, which focuses on pelvic stability, to categorize the fractures. 10,11 According to this classification, type A fractures are rotationally and vertically stable; type fractures are vertically stable but rotationally unstable owing to an incomplete posterior arch disruption; and type fractures are vertically and rotationally unstable owing to a complete posterior arch disruption. Three groups were defined: group A included patients without Sigleed; group included patients with Sigleed of a nonpelvic cause (eg, splenic or liver laceration); and group included patients with Sigleed caused by the SPF. The distinction between groups and was based on the presence of other injuries causing bleeding, such as a splenic or liver laceration (group ) or a large pelvic hematoma with extravasation on T scans (group ). Statistical analysis was performed with PASW for Windows, version 17.0 (SPSS Inc, hicago, Illinois). omparisons among the 3 groups were conducted with 1-way analysis of variance for continuous variables with normal distributions and with the Kruskal-Wallis test for continuous variables without normal distributions. ategorical variables were analyzed using the 2 test and the Fisher exact test. For all the continuous variables that could serve as risk factors, we created dichotomous variables using clinically relevant cutoff points. We then focused on the analysis of patients who did not have bleeding from a nonpelvic source. For this reason, we excluded group patients from further analysis. ecause of the small sample size of group, we included the 3 most significant factors identified in the univariate analysis in a logistic regression model to identify independent predictors of Sigleed in group compared with group A. The odds ratios (ORs) and 95% confidence intervals (Is) of each independent predictor were calculated. P.05 was considered statistically significant. The study protocol was reviewed and approved by the institutional review board of Massachusetts General Hospital. RESULTS 6 Patients 15 Patients received underwent angiography transfusion only (5 embolized) Figure 1. Flowchart showing our study patient population and the breakdown of the 3 groups. Of 465 patients with SPFs, 74 were excluded (64 patients did not have a pelvic T scan; 6 patients were transfused for chronic diseases; and 4 patients with unstable pelvic fractures died before receiving their intended operation). Finally, 391 patients formed the study population and were included in the analysis. There were 280 patients (72%) in group A, 90 (23%) in group, and 21 (5%) in group (Figure 1). A total of 310 patients (79%) had a Tile type A fracture and 20 (5%) had a Tile type. Also, 61 patients (16%) had an isolated acetabular fracture. y definition, there were no type fractures. Six patients (29%) in group underwent angiography, and 5 (24%) proceeded to embolization. The mean (SD) hospital stay for the entire population was 8.6 (8.6) days, and 16 patients died (4%). In 3 patients, the pelvic bleeding was the cause of, or a significant contributor to, their death. An 83-year-old patient with SPFs, lower-extremity fractures, and upper-extremity degloving injuries died 24 hours after receiving multiple blood transfusions. A 91-year-old patient with SPFs and a humerus fracture underwent angiography, but no extravasation was found, and she did not undergo embolization. On posttrauma day 8, she died of multiorgan failure related to the initial bleeding. Finally, a 75-year-old multitrauma patient (SPFs, head injury, and lower- and upper-extremity fractures) underwent massive resuscitation and bilateral internal iliac embolization twice. He developed abdominal compartment syndromes, requiring decompression. Despite successful control of the bleeding, he died on posttrauma day 10 for the same reasons as those of the previous patient. GROUP A VS GROUP As expected, compared with the patients without Sigleed, those in group were older and had a lower admission SP and Hct and a higher rate of coumadin use. More group A patients required IU admission. They had longer IU and hospital stays and a higher mortality (Table 1). GROUP VS GROUP The 2 groups had comparable units of packed red blood cells and fresh-frozen plasma transfusions, type of frac- 408

3 Table 1. Patient haracteristics and Outcomes Variable A (n=280) Group a (n=90) (n=21) P Value Male sex 135 (48) 47 (52) 8 (38).001 Age, mean (SD), y 55 (25) 55 (24) 79 (15).001 Age 65 y 117 (42) 36 (40) 18 (86).001 Mechanism of injury.001 Fall 156 (56) 19 (20) 16 (76) Motor vehicle crash 113 (40) 65 (72) 5 (24) Other 11 (4) 6 (7) 0 Type of fracture.04 Isolated acetabular 45 (16) 15 (17) 1 (5) Tile A b 222 (79) 69 (77) 19 (91) Tile b 13 (5) 6 (7) 1 (5) Evidence of pelvic hematoma on T 86 (31) 33 (37) 20 (95) c.001 Receiving coumadin therapy 17 (6) 4 (5) 5 (25).01 Receiving -blocker therapy 52 (19) 14 (17) 4 (20).77 Hematocrit, mean (SD), % 38 (5) 34 (6) 30 (5).001 Hematocrit 30% 7 (3) 20 (22) 12 (57).001 lood units transfused in first 24 h, mean (SD) 0 6 (9) 8 (13).001 Fresh-frozen plasma units transfused in first 24 h, mean (SD) 0 3 (8) 5 (10).001 SP on admission, mean (SD), mm Hg 138 (27) 124 (27) 120 (30).001 SP 90 mm Hg 5 (2) 9 (11) 4 (19).001 Heart rate, mean (SD), beats/min 87 (19) 93 (23) 87 (22).15 Heart rate 100, beats/min 73 (26) 29 (32) 5 (24).43 GS 13 5 (2) 3 (3) 1 (5).43 ISS, mean (SD) 13 (10) 26 (13) 16 (11).001 ISS (12) 44 (49) 6 (29).001 Abdomen AIS 3 12 (4) 19 (21) 3 (14).001 Head/neck AIS 3 39 (14) 38 (42) 3 (14).001 hest AIS 3 53 (19) 52 (58) 6 (29).001 Extremities AIS (44) 69 (77) 13 (62).001 Face AIS 2 24 (9) 22 (24) Patients requiring IU 31 (11) 60 (70) 8 (38).001 IU stay, mean (SD), d 0.6 (2) 5 (6) 4 (7).001 Hospital stay, mean (SD), d 7 (6) 14 (11) 15 ( Mortality 5 (2) 8 (9) 3 (14).001 Abbreviations: AIS, abbreviated injury score; T, computed tomography; GS, Glasgow oma Score; IU, intensive care unit; ISS, injury severity score; SP, systolic blood pressure. a Values are given as number (percentage) unless otherwise indicated. b See Methods section for definition of Tile classification. c ecause of a right hip prosthesis, which caused a significant artifact, findings on pelvic T of the remaining patient from group were inconclusive regarding the existence of a pelvic hematoma. tures, length of hospital stay, and mortality. However, patients in group were older, more frequently injured after a fall, and had a lower injury severity score and admission Hct. They were less likely to be admitted to the IU (Table 1). The sources of hemorrhage in group are described in Table 2. INDEPENDENT RISK FATORS OF SIGLEED FROM SPFs The multivariable analysis of group vs group A produced the following independent predictors of Sigleed from SPFs: an Hct of 30% or lower (OR, 43.93; 95% I, ; P.001); the presence of pelvic hematoma on T (OR, 39.37; 95% I, ; P.001); and an SP of 90 mm Hg or lower (OR, ; 95% I, ; P=.01). When all 3 independent predictors were present, 100% of the patients had Sigleed; when all 3 were absent no one had Sigleed. Table 2. Abdominal and Extra-abdominal Sources of leeding in Groups and a Injuries (n=90) Group (n=21) P Value Intra-abdominal sources, No. (%) 37 (41) 1 (5) b.002 Liver 18 1 Spleen 12 0 Hollow viscus 8 0 Other 16 1 Extra-abdominal sources, No. (%) 75 (83) 8 (38).001 Thorax 16 0 Head/neck 40 5 Extremities 53 7 a There were patients with multiple sources of bleeding. b The single patient in group with an intra-abdominal source of bleeding had a small (grade I) liver hematoma and an adrenal hematoma, but the bleeding from the sizable pelvic hematoma was clearly the indication for transfusion. 409

4 A D E Figure 2. Pelvic computed tomographic scan of a 79-year-old woman receiving coumadin therapy who presented to the emergency department after a fall. Despite the fact that the plain pelvic radiographs did not identify any tissue, joint, or bone abnormalities, the pelvic computed tomographic scan with intravenous contrast showed a large right pelvic hematoma associated with a small superior pubic ramus fracture (A [arrow] and ). The hematoma displaces the bladder to the left, and multiple foci of contrast extravasation are evident, indicative of active bleeding (). On the angiogram, the right obturator artery was identified as the culprit bleeding vessel (D) and successfully embolized with an absorable gelatin sponge (Gelfoam) (E). OMMENT To our knowledge, this is the first study focusing on bleeding from SPFs. Although Sigleed occurred in one-third of the patients, the SPF was the cause of it in only 5% of them. The overall mortality rate of 0.8%, which is directly associated with the pelvic bleeding, is similar to the rate reported in other studies. 4,5 It is well known that among severe pelvic fractures there are specific patterns, such as vertical shear fractures, bilateral pubic rami (butterfly) fractures, and pubic symphysis widening of more than 2.5 cm, that are associated with a higher likelihood of bleeding. 6,12,13 According to our findings, the only 3 independent risk factors that predicted bleeding in patients with SPFs were an Hct of 30% or lower, the presence of a pelvic hematoma on T, and an admission SP of 90 mm Hg or lower. It is therefore reasonable to assume that hypotension and anemia in a patient with an SPF and no other sources of intra-abdominal hemorrhage indicate pelvic bleeding unless proved otherwise. These findings should translate to an increased level of vigilance for relevant patients. Such patients should either have an early intervention or be monitored closely in a higher-care unit. Since external fixation is not appropriate for an SPF, the only potential interventions would be angiographic embolization or preperitoneal pelvic packing, the former being a more preferable option than the latter. The indications for angiographic embolization after pelvic fractures are controversial. It has been suggested that SP, Hct, heart rate, age, blood transfusion, a blush on T, and fracture pattern are predictors of active bleeding on angiography. 7,14,15 Six of our group patients underwent angiography, and 5 proceeded to embolization within 24 hours after presentation to the emergency department (Figure 2). Three patients underwent embolization of an internal iliac artery. Two patients underwent subselective embolization of the obturator and the superior gluteal arteries, respectively, and 1 patient underwent bilateral internal iliac artery embolization, as previously described in the literature. 16 Of those 5 patients who underwent embolization, all demonstrated evidence of hemodynamic instability during the initial hours of their hospitalization, and 1 eventually died. Preperitoneal pelvic packing has been described as a method to control acute pelvic bleeding if (1) angiography is not readily available, (2) the patient is in extremis, or (3) an emergent operation is needed before angiography. 17 In our population, no preperitoneal pelvic packings were performed. In our institution, the interventional radiology team provides an around-the-clock service, which allows expeditious transfer of even severely injured patients to the angiography table, with an intensive care team providing continuous care. For this reason, preperitoneal pelvic packing for control of pelvic bleeding is infrequently practiced. 410

5 We therefore suggest the following clinical pathway for patients with SPFs and no other clinically significant injuries: If none of the 3 risk factors is present, the patient can be safely treated in a regular hospital bed or potentially discharged. If 1 or 2 of the risk factors exist, the patient should be monitored in an intensive care environment, and a low threshold for intervention should be maintained. If all of the risk factors exist, the patient should undergo emergent angiography or preperitoneal pelvic packing according to the circumstances. Except for Hct and SP, the multivariate analysis did not identify other independent predictors of bleeding. In accordance with other studies emphasizing age, 18 our univariate analysis showed that the rate of patients older than 65 years was more than double in group compared with group A (86% vs 42%). However, age was not identified as an independent predictor of bleeding. Similarly, other factors, such as coumadin use (P=.79) and associated injuries (injury severity score) (P=.13), which were expected to make a difference, did not achieve significance in the multivariable analysis. The limited sample size of this retrospective study may affect the results of the analysis and may be the main reason for preventing seemingly important clinical factors from becoming statistically significant. However, it is unlikely that large numbers of bleeding patients with SPFs will be described in single-institution studies. These patients are infrequent and will remain so. For the same reason (limited sample size), the 95% I intervals of the selected independent risk factors were very wide. Obviously, the small sample size decreases the confidence in the true effect size of these factors from a statistical point of view. linically, it makes sense that 1 radiographic and 2 hemodynamic parameters predict Sigleed. Another limitation of our study is that 1 of our outcomes (blood transfusion) was not standardized and therefore was subjected to the treating physicians personal preferences. Finally, the decision to perform angiography was left to the discretion of the trauma surgeon, although our team operates under a written protocol that provides guidelines for the management of pelvic fractures. An SPF is often dismissed as a source of Sigleed, possibly resulting in delays of care. Our study shows that Sigleed from SPFs is indeed an infrequent event and happens in only 5% of patients with SPFs. However, it can be predicted by 3 simple parameters: an Hct of 30% or lower, the presence of a pelvic hematoma in T scan, and an admission SP of 90 mm Hg or lower. For those few patients with SPFs and a high likelihood of Sigleed, early intervention or close monitoring is essential. Accepted for Publication: September 10, Published Online: December 20, doi: /archsurg orrespondence: George. Velmahos, MD, PhD, Division of Trauma, Emergency Surgery, and Surgical ritical are, Massachusetts General Hospital, 165 ambridge St, Ste 810, oston, MA Author ontributions: Study concept and design: ramos, Velmahos, utt, Fikry, and Smith. Acquisition of data: ramos and utt. Analysis and interpretation of data: ramos, Velmahos, and hang. Drafting of the manuscript: ramos, Velmahos, and utt. ritical revision of the manuscript for important intellectual content: Fikry, Smith, and hang. Statistical analysis: ramos, utt, Fikry, and hang. Study supervision: ramos, Velmahos, and Smith. Financial Disclosure: None reported. REFERENES 1. Sathy AK, Starr AJ, Smith WR, et al. The effect of pelvic fracture on mortality after trauma: an analysis of 63,000 trauma patients. J one Joint Surg Am. 2009; 91(12): Poole GV, Ward EF, Muakkassa FF, Hsu HS, Griswold JA, Rhodes RS. Pelvic fracture from major blunt trauma: outcome is determined by associated injuries. 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