Brigham K. Au

Damage control hematology: The impact of a trauma exsanguination protocol on survival and blood product utilization

BACKGROUND The importance of early and aggressive management of trauma- related coagulopathy remains poorly understood. We hypothesized that a trauma exsanguination protocol (TEP) that systematically provides specified numbers and types of blood components immediately upon initiation of resuscitation would improve survival and reduce overall blood product consumption among the most severely injured patients. METHODS We recently implemented a TEP, which involves the immediate and continued release of blood products from the blood bank in a predefined ratio of 10 units of packed red blood cells (PRBC) to 4 units of fresh frozen plasma to 2 units of platelets. All TEP activations from February 1, 2006 to July 31, 2007 were retrospectively evaluated. A comparison cohort (pre-TEP) was selected from all trauma admissions between August 1, 2004 and January 31, 2006 that (1) underwent immediate surgery by the trauma team and (2) received greater than 10 units of PRBC in the first 24 hours. Multivariable analysis was performed to compare mortality and overall blood product consumption between the two groups. RESULTS Two hundred eleven patients met inclusion criteria (117 pre-TEP, 94 TEP). Age, sex, and Injury Severity Score were similar between the groups, whereas physiologic severity (by weighted Revised Trauma Score) and predicted survival (by trauma-related Injury Severity Score, TRISS) were worse in the TEP group (p values of 0.037 and 0.028, respectively). After controlling for age, sex, mechanism of injury, TRISS and 24-hour blood product usage, there was a 74% reduction in the odds of mortality among patients in the TEP group (p = 0.001). Overall blood product consumption adjusted for age, sex, mechanism of injury, and TRISS was also significantly reduced in the TEP group (p = 0.015). CONCLUSIONS We have demonstrated that an exsanguination protocol, delivered in an aggressive and predefined manner, significantly reduces the odds of mortality as well as overall blood product consumption.

Optimizing outcomes in damage control resuscitation: identifying blood product ratios associated with improved survival.

BACKGROUND Despite recent attention and impressive results with damage control resuscitation, the appropriate ratio of blood products to be transfused has yet to be defined. The purpose of this study was to evaluate whether suggested blood product ratios yield superior survival rates. MATERIALS After IRB approval, a retrospective evaluation was performed on all trauma exsanguination protocol (TEP, n = 118) activations from February 1, 2006 to July 31, 2007. A comparison cohort (pre-TEP, n = 140) was selected from all trauma admissions between August 1, 2004 and January 31, 2006 that (1) underwent immediate surgery by the trauma team and (2) received greater than 10 units of PRBC in the first 24 hours. We then compared those who received FFP:RBC (2:3) and platelet:RBC (1:5) ratios with those who did not reach these ratios. Multivariate analysis was performed for independent predictors of mortality. RESULTS A total of 259 patients were available for study. Patients receiving FFP:RBC at a ratio of 2:3 or greater (n = 64) had a significant reduction in 30-day mortality compared with those who received less than a 2:3 ratio (n = 195); 41% versus 62%, p = 0.008. Patients receiving platelets:RBC at a ratio of 1:5 or greater (n = 63) had a lower 30-day mortality when compared with those with who received less than this ratio (n = 196); (38% vs. 61%, p = 0.001). Regression model demonstrated that a ratio of FFP to PRBC is an independent predictor of 30-day mortality, controlling for age and TRISS (OR 1.78, 95% CI 1.01-3.14). CONCLUSIONS Increased FFP:PRBC and PLT:PRBC ratios during a period of massive transfusion improved survival after major trauma. Massive transfusion protocols should be designed to achieve these ratios to provide maximal benefit.

Predefined massive transfusion protocols are associated with a reduction in organ failure and postinjury complications.

INTRODUCTION Massive transfusion (MT) protocols have been shown to improve survival in severely injured patients. However, others have noted that these higher fresh frozen plasma (FFP):red blood cell (RBC) ratios are associated with increased risk of organ failure. The purpose of this study was to determine whether MT protocols are associated with increased organ failure and complications. METHODS Our institutions exsanguination protocol (TEP) involves the immediate delivery of products in a 3:2 ratio of RBC:FFP and 5:1 for RBC:platelets. All patients receiving TEP between February 2006 and January 2008 were compared with a cohort (pre-TEP) of all patients from February 2004 to January 2006 that (1) went immediately to the operating room and (2) received MT (>or=10 units of RBC in first 24 hours). RESULTS Two hundred sixty-four patients met inclusion (125 in the TEP group, 141 in the pre-TEP). Demographics and Injury Severity Score were similar. TEP received more intraoperative FFP and platelets but less in first 24 hours (p < 0.01). There was no difference in renal failure or systemic inflammatory response syndrome, but pneumonia, pulmonary failure, open abdomens, and abdominal compartment syndrome were lower in TEP. In addition, severe sepsis or septic shock and multiorgan failure were both lower in the TEP patients (9% vs. 20%, p = 0.011 and 16% vs. 37%, p < 0.001, respectively). CONCLUSIONS Although MT has been associated with higher organ failure and complication rates, this risk appears to be reduced when blood products are delivered early in the resuscitation through a predefined protocol. Our institutions TEP was associated with a reduction in multiorgan failure and infectious complications, as well as an increase in ventilator-free days. In addition, implementation of this protocol was followed by a dramatic reduction in development of abdominal compartment syndrome and the incidence of open abdomens.

Exsanguination protocol improves survival after major hepatic trauma

BACKGROUND Hepatic injury remains an important cause of exsanguination after major trauma. Recent studies have noted a dramatic reduction in mortality amongst severely injured patients when trauma exsanguinations protocols (TEP) are employed. We hypothesised that utilisation of our institutions TEP at the initiation of hospital resuscitation would improve survival in patients with significant hepatic trauma. PATIENTS AND METHODS All patients who (1) sustained intra-abdominal haemorrhage with Grades III-V hepatic injury and (2) underwent immediate operative intervention between February 2004 and January 2008 were included in the study. TEP was instituted in February 2006, and all subsequent patients who met inclusion criteria and were treated with TEP constituted the study group. Patients who met inclusion criteria, were treated before introduction of TEP, and received at least 10 units packed red blood cells in the first 24h constituted pre-TEP comparison group. Univariate and multivariate analyses evaluated the effects of TEP on the study population. RESULTS Seventy-five patients were included in the study: 39 in the pre-TEP cohort (31% 30-day survival) and 36 in the TEP cohort (53% 30-day survival). There were no differences in demographics, extent of hepatic injury, or operative approach between the patient groups (all p > or = 0.27). Injury Severity Scores were significantly higher in the TEP group (41+/-18 vs. 28+/-15, p<0.01). TEP patients received more plasma and platelets during operative intervention and significantly less crystalloid (all p<0.01). Occurrence of cardiac dysfunction and abdominal compartment syndrome was significantly lower in TEP patients who survived 24-h post-injury (both p < or = 0.04). After adjusting for the significant negative effects of Grade V injury and involvement of major hepatic vasculature (both p < or = 0.02), TEP significantly improved 30-day survival: OR=0.22, 95% CI: 0.06-0.81, p=0.02. CONCLUSIONS TEP allows for an effective use of plasma and platelets during intra-operative management of severe hepatic injury. Utilisation of TEP is associated with significant reductions of cardiac dysfunction and development of abdominal compartment syndrome, as well as, significant improvement in 30-day survival.

Hyperkalemia Following Massive Transfusion in Trauma

BACKGROUND Large-volume blood transfusions have been implicated in the development of hyperkalemia. The purpose of the current study was to determine whether critically injured patients receiving massive transfusions are at an increased risk of hyperkalemia. METHODS Massive transfusion (MT) cohort, all trauma patients (02/2004-01/2008) taken directly to the OR and receiving >or=10 units of RBC in first 24h. Comparison cohort (No-RBC), all patients (02/2004-01/2008) transported directly to the OR who received no blood products in the first 24h. Hyperkalemia defined as K+ > 5.5 mEq/L. RESULTS There were 266 MT patients, 237 No-RBC patients. MT patients were more likely to have hyperkalemia in the immediate postoperative setting (1.8% versus 4.6%, P = 0.049). However, linear regression did not identify intraoperative blood transfusions as a predictor of postoperative K+ values (P = 0.417). Logistic regression identified only preop K+ (OR 1.79, P = 0.021) and postop pH (OR 0.009, P = 0.001), but not MT, as independent risk factors for postop hyperkalemia. CONCLUSIONS Despite concerns of hyperkalemia following MT, we found less than a 5% incidence of postop K+ (>5.5 mEq/L). After adjusting for the significant effects of preop K+ and postop pH, MT patients were at no higher risk of hyperkalemia than those who received no blood products.

Comparison of 3 Methods for Maintaining Inter-Fragmentary Compression After Fracture Reduction and Fixation.

Objectives: It is recommended that the intra-articular component of a supracondylar distal femoral fracture be stabilized by a lag screw to create interfragmental compression. Generally, it is thought that lag screw fixation should precede any positional screw or locking screw application. This study compared 3 methods of maintaining interfragmentary compression after fracture reduction with a reduction clamp. Methods: Intra-articular vertical split fractures were created in synthetic femora. A force transducer was interposed between the medial and lateral condyles and 20 lbs of compression was applied to the fracture with a reduction clamp. 3.5-mm cortical lag screws (group 1), 3.5-mm cortical position screws (group 2), and 5.4-mm distal locking screws through a distal femur locking plate (group 3) were placed across the fracture (n = 4/group). After screw placement, the clamp was removed and the amount of residual interfragmentary compression was recorded. After 2 minutes, a final steady-state force was measured and compared across groups. Results: Locking screws placed through the plate (group 3) maintained 27% of the initial force applied by the clamp (P = 0.043), whereas positional screws (group 2) maintained 90% of the initial force applied by the clamp (P = 0.431). The steady-state compression force measured with lag screws (group 1) increased by 240% (P = 0.030) relative to the initial clamp force. The steady-state force in the lag screw group was significantly greater than groups 1 and 2 (P = 0.012). Conclusions: When reducing intra-articular fractures and applying interfragmentary compression with reduction clamps, additional lag screws increase the amount of compression across the fracture interface. Compressing a fracture with reduction clamps and relying on locking screws to maintain the compression result in a loss of interfragmentary compression and should be avoided. This study lends biomechanical support that lag screws placed outside of the plate before locking screws for fracture fixation help maintain optimal interfragmentary compression.

Rotational osteoplasty for femoral head fracture with cartilage loss.

Femoral head fractures often result in damage to the articular cartilage. This article describes a patient who sustained a femoral head fracture-dislocation with significant damage to the articular cartilage of the weight-bearing portion of his femoral head (A). After anatomic reduction of the fracture, a 2×4-cm osteochondral articular defect existed at the weight-bearing portion of the femoral head (B). The femoral head fragment was rotated such that the superior weight-bearing surface was congruent (C). This created a small gap at the inferior aspect of the femoral head, which was filled using a small corticocancellous graft harvested from the greater trochanter. The femoral head fragment was fixed with countersunk 3.5-mm screws. At 18-month follow-up, the patient had returned to full-time construction work with no limitations. He reported no pain in his hip or any activity limitations, and his Harris Hip Score was 91 points. Radiographs obtained 18 months postoperatively showed healing of the femoral head and preservation of the hip joint.