To the editor, Ultrasound-guided femoral nerve block immediately distal to the inguinal ligament at about the inguinal skin crease is a standard regional anesthesia technique for lower extremity surgery.[1 2][1] Performance of the block requires ultrasound identification of the femoral nerve in the

BACKGROUND: Dysfunctional inflammation following traumatic hemorrhage can lead to multiple-organ failure and death. In our polytrauma swine model, lyophilized plasma (LP) reconstituted with sterile water and ascorbic acid suppressed systemic inflammation and attenuated DNA damage. However, it remains unknown whether the inflammatory response is affected by the type of fluid used to reconstitute LP. We hypothesized that common resuscitation fluids such as normal saline (LP-NS), lactated Ringer's solution (LP-LR), Hextend (LP-HX), or sterile water (LP-SW) would yield similar inflammation profiles and DNA damage following LP reconstitution and transfusion. METHODS: This was a randomized, prospective, blinded animal study. LP was reconstituted to 50% of original volume with NS, LR, HX, or SW buffered with 15-mM ascorbic acid. Forty swine were subjected to a validated model of polytrauma, hemorrhagic shock, and Grade V liver injury and resuscitated with LP. Serum interleukin 6 (IL-6), IL-10, plasma C-reactive protein, and 8-hydroxy-2-deoxyguanosine concentrations were assessed for systemic inflammation and DNA damage at baseline, 2 hours, and 4 hours following liver injury. Lung inflammation was evaluated by Real Time Polymerize Chain Reaction (RT-PCR). RESULTS: Reconstituted LP pH was similar between groups before resuscitation. IL-6 and IL-10 increased at 2 hours and 4 hours compared with baseline in all groups (p < 0.017). DNA damage increased at 2 hours and 4 hours compared with baseline and from 2 hours to 4 hours in the LP-NS, LP-LR, and LP-SW groups (all p < 0.017). Animals resuscitated with LP-HX not only demonstrated increased DNA damage at 4 hours versus baseline but also had the lowest C-reactive protein level at 2 hours and 4-hours (p < 0.017). Overall, differences between groups were similar for DNA damage and lung inflammation. CONCLUSION: Reconstitution fluid type does not affect inflammatory cytokine profiles or DNA damage following LP transfusion in this swine polytrauma model. Based on universal availability, these data suggest that sterile water is the most logical choice for LP reconstitution in humans. (Copyright (C) 2015 Wolters Kluwer Health, Inc. All rights reserved.)

BACKGROUND Compared with lyophilized plasma (LP) buffered with other acids, LP with ascorbic acid (AA) attenuates systemic inflammation and DNA damage in a combat relevant polytrauma swine model. We hypothesize that increasing concentrations of AA in transfused LP will be safe, will be hemodynamically well tolerated, and will attenuate systemic inflammation following polytraumatic injury and hemorrhage in swine.METHODS This prospective, randomized, blinded study involved 52 female swine. Forty animals were subjected to our validated polytrauma model and resuscitated with LP. Baseline control sham (n = 6), operative control sham (n = 6), low-AA (n = 10), medium-AA (n = 10), high-AA (n = 10) groups, and a hydrochloric acid control (HCL, n = 10) were randomized. Hemodynamics, thrombelastography, and blood chemistries were assessed. Inflammatory cytokines (tumor necrosis factor , interleukin 6 [IL-6], C-reactive protein, and IL-10) and DNA damage were measured at baseline, 2 hours, and 4 hours after liver injury. Significance was set at p < 0.05, with a Bonferroni correction for multiple comparisons.RESULTS Hemodynamics, shock, and blood loss were similar between groups. All animals had robust procoagulant activity 2 hours following liver injury. Inflammation was similar between groups at baseline, and AA groups remained similar to HCL following liver injury. IL-6 and tumor necrosis factor were increased at 2 hours and 4 hours compared with baseline within all groups (p < 0.008). DNA damage increased at 2 hours compared with baseline in all groups (p < 0.017) and further increased at 4 hours compared with baseline in HCL, low-, and high-AA groups (p < 0.005). C-reactive protein was similar between and within groups. IL-10 increased at 2 hours compared with baseline in low- and high-AA groups and remained elevated at 4 hours compared with baseline in the low-AA group (all, p < 0.017).CONCLUSION Concentrations of AA were well tolerated and did not diminish the procoagulant activity of LP. Within our tested range of concentrations, AA can safely be used to buffer LP.

BACKGROUND Low-volume ascorbic acid–buffered reconstituted lyophilized plasma (LP) provides logistic advantages, reduces the risks for large-volume resuscitation, modulates inflammation, and is equally effective for hemostatic resuscitation as full-volume LP. We compared the physiologic effects of resuscitation using LP reconstituted with sterile water (LP-SW), lactated Ringer’s solution (LP-LR), normal saline (LP-NS), and Hextend (LP-Hx). METHODS Plasma was collected from swine, lyophilized, and then reconstituted into four test solutions: LP-SW, LP-LR, LP-NS, or LP-Hx. Forty swine were anesthetized and subjected to a validated model of polytrauma and hemorrhagic shock (including a Grade V liver injury), then randomized to receive one of the four test solutions. Physiologic parameters, blood loss, lactate, and hematocrit were followed up. Coagulation status was evaluated using thrombelastography. Inflammatory mediator expression was evaluated by multiplex serum assay. RESULTS Forty animals were included in the study (10 animals per group). One animal died following LP-Hx resuscitation. There was less blood loss in the LP-SW and LP-LR groups compared with the LP-NS and LP-Hx groups (p < 0.05). The LP-SW group exhibited less early coagulopathic changes by thrombelastography, and the LP-Hx group had persistently elevated international normalized ratios at the end of the study period (p < 0.05). Serum interleukin 6 was lower after 4 hours in the LP-SW group compared with LP-NS (p < 0.05). CONCLUSION Resuscitation using low-volume LP-SW and LP-LR buffered with ascorbic acid confers an anti-inflammatory benefit and results in less blood loss. Sterile water is a safe, cost-effective, and universally available fluid for creating a low-volume hemostatic LP resuscitation solution.

BACKGROUND:Rapid thrombelastography (rTEG) is a real-time whole-blood viscoelastic coagulation assay. We hypothesized that admission rTEG and clinical data are independent predictors of trauma-related mortality. METHODS:Prospective observational data (patient demographics, admission vital signs, laboratory studies, and injury characteristics) from trauma patients enrolled within 6 hours of injury were collected. Mann-Whitney U test and analysis of variance test assessed significance (P ≤ .05). Logistic regression analyses determined the association of the studied variables with 24-hour mortality. RESULTS:Seven hundred ninety-five trauma patients were enrolled, of which 55 died within 24 hours of admission. Admission variables which independently predicted 24-hour mortality were as follows: Glasgow Coma Scale ≤8, hemoglobin <11 g/dL, international normalized ratio >1.5, Ly30 >8%, and penetrating injury (P < .05). This 5-variable model's area under the receiver operator characteristic curve was .88. The Hosmer-Lemeshow goodness-of-fit test was .90. CONCLUSIONS:This 5-variable model provides a rapid prediction of 24-hour mortality. The inclusion of rTEG Ly30 demonstrates the association of fibrinolysis with outcome and may support the early use of antifibrinolytic therapies.

McCully, Sean P. MD; Hampton, David A. MD; Lee, Tim H. MD; Redick, Brittney J. BA; Kutcher, Matthew E. MD; Podbielski, Jeanette M. RN, BSN; Diggs, Brian S. PhD; Cotton, Bryan A. MD, MPH; Cohen, Mitchell J. MD, FACS; Schreiber, Martin A. MD, FACS Author Information

BACKGROUND:Shock and severe tissue injury lead to an endogenous coagulopathy mediated by activation of Protein C and hyperfibrinolysis known as acute traumatic coagulopathy. Together, hemodilution, acidosis, inflammation, and hypothermia result in a global trauma-induced coagulopathy. Coagulopathy in trauma is associated with mortality. Early and effective hemostatic resuscitation is critical in restoring perfusion, correcting coagulopathy, and saving lives in exsanguinating trauma. Lyophilized plasma (LP) provides a logistically superior alternative to fresh frozen plasma (FFP).STUDY DESIGN AND METHODS:Plasma was lyophilized following whole blood collection from anesthetized swine. A series of studies were performed using anesthetized swine subjected to a validated model of polytrauma and hemorrhagic shock including a Grade V liver injury. Animals were randomized to resuscitation using reconstituted LP fluids. Physiologic data and blood loss were measured. Coagulation status and inflammatory mediators were evaluated.RESULTS:Full volume reconstituted LP (100%LP) retains on average 86% coagulation factor activity compared to fresh plasma and when used in 1:1 ratios with red blood cells demonstrated superior hemostatic efficacy compared to FFP. Hypertonic LP reconstituted using 50% of the original plasma volume (50%LP) had higher coagulation factor concentrations, was well tolerated in swine, and equally effective compared to 100%LP with respect to physiologic and hemostatic properties. Buffering with ascorbic acid resulted in significant reductions in serum levels of tumor necrosis factor alpha and interleukin-6.CONCLUSION:By minimizing the volume of reconstituted LP and optimizing its anti-inflammatory properties, an LP resuscitation fluid may be created to provide effective hemostatic resuscitation with superior logistical properties.

Hampton, David A. MD; McCully, Belinda H. PhD; Lee, Tim H. MD; Kutcher, Matthew MD; Redick, Britt J. BA; Podbielski, Jeanette BS; Welch, Timothy; Cohen, Mitchell J. MD, FACS; Cotton, Bryan A. MD, FACS; Schreiber, Martin A. MD, FACS Author Information

BACKGROUND:Pericardiocentesis (PCC) had been taught as a mandatory skill in the Advanced Trauma Life Support (ATLS®) course as a bridge to definitive surgical therapy for traumatic pericardial tamponade since its inception in 1978. Immediate thoracotomy for penetrating trauma to the heart and chest has resulted in the decreased use of PCC in trauma. PCC is now offered as an optional skill in the ninth edition of the ATLS®. A review of the literature regarding the use and effectiveness of PCC in traumatic pericardial tamponade in the modern era is necessary to better define its current role in trauma care.METHODS:Scientific publications from 1970 to 2010 involving PCC after trauma were identified. The Preferred Reporting Items for Systematic reviews and Meta-Analyses was used. Human studies describing acute traumatic tamponade were included. Publications involving nontraumatic or chronic pericardial tamponade from effusions caused by inflammatory, infectious, or neoplastic etiology were excluded. Publications were categorized by level of evidence.RESULTS:Of the 135 publications identified, 27 were included, composing of 2,094 trauma patients with suspected cardiac tamponade. The reported use of PCC decreased from 45.9% of patients in the period 1970 to 1979 down to 6.4% of patients in the period between 2000 and 2010 (p < 0.05). Reported rates describing the use of PCC as the sole intervention decreased from 13.7% in the period 1970 to 1979 to 2.1% in the period 2000 to 2010 (p < 0.05). Survival analysis after PCC was possible for 380 patients. Overall survival following PCC was 83.4% (n = 317) and 91.8% (n = 145) when used as the sole intervention. In patients who received PCC then thoracotomy, survival rate was 79.5% (n = 178).CONCLUSION:Studies on the use of PCC for trauma are limited and biased toward survivors. The reported survival rate is high. There remains a limited role for PCC in nontrauma centers where definitive surgical management is not immediately available and transport time to a higher level of care facility supports the use of temporary decompression by PCC.LEVEL OF EVIDENCE:Systematic review, level III.

BACKGROUND Pericardiocentesis (PCC) had been taught as a mandatory skill in the Advanced Trauma Life Support (ATLS®) course as a bridge to definitive surgical therapy for traumatic pericardial tamponade since its inception in 1978. Immediate thoracotomy for penetrating trauma to the heart and chest has resulted in the decreased use of PCC in trauma. PCC is now offered as an optional skill in the ninth edition of the ATLS®. A review of the literature regarding the use and effectiveness of PCC in traumatic pericardial tamponade in the modern era is necessary to better define its current role in trauma care. METHODS Scientific publications from 1970 to 2010 involving PCC after trauma were identified. The Preferred Reporting Items for Systematic reviews and Meta-Analyses was used. Human studies describing acute traumatic tamponade were included. Publications involving nontraumatic or chronic pericardial tamponade from effusions caused by inflammatory, infectious, or neoplastic etiology were excluded. Publications were categorized by level of evidence. RESULTS Of the 135 publications identified, 27 were included, composing of 2,094 trauma patients with suspected cardiac tamponade. The reported use of PCC decreased from 45.9% of patients in the period 1970 to 1979 down to 6.4% of patients in the period between 2000 and 2010 (p < 0.05). Reported rates describing the use of PCC as the sole intervention decreased from 13.7% in the period 1970 to 1979 to 2.1% in the period 2000 to 2010 (p < 0.05). Survival analysis after PCC was possible for 380 patients. Overall survival following PCC was 83.4% (n = 317) and 91.8% (n = 145) when used as the sole intervention. In patients who received PCC then thoracotomy, survival rate was 79.5% (n = 178). CONCLUSION Studies on the use of PCC for trauma are limited and biased toward survivors. The reported survival rate is high. There remains a limited role for PCC in nontrauma centers where definitive surgical management is not immediately available and transport time to a higher level of care facility supports the use of temporary decompression by PCC. LEVEL OF EVIDENCE Systematic review, level III.

BACKGROUND Deep vein thrombosis (DVT) is common after trauma. Pulmonary embolism (PE) is a feared complication of DVT. Standard doses of low-molecular-weight heparin (LMWH) are commonly used to prevent and treat DVT and PE. There is variable bioavailability of LMWH with standard therapy. The traditional concept that below-knee DVT is associated with a lower risk of subsequent PE may result in less aggressive therapy. The purposes of this study were to assess the rates of PE in above-knee versus below-knee DVT and longitudinally evaluate outcomes of DVT treated with LMWH therapy. METHODS This was a retrospective review of patients at a university Level I trauma center during the years 2005 through 2010. Patients diagnosed with lower-extremity DVT were included in this study. Patients were classified by location of lower-extremity DVT and type of LMWH therapy received. All high-risk trauma patients were evaluated with weekly duplex Doppler ultrasonography. All duplex studies were reviewed for DVT resolution or improvement. Symptomatic patients were evaluated with computed tomographic angiography to rule out PE. Demographics, total length of hospital stay, length of intensive care unit stay, and Injury Severity Score (ISS) were collected. RESULTS Three-hundred eight trauma patients with lower-extremity DVT were included. More patients developed below-knee DVT (65.6%) compared with above-knee DVT (34.4%). Increased length of hospital stay, intensive care unit stay, and higher ISS were noted in patients with above-knee DVT. More patients had below-knee DVT in the prophylactic dosing group. With LMWH therapy, three PEs occurred in patients in the prophylactic dosing group with below-knee DVT, and no PEs occurred in the therapeutic treatment group. The incidence of PE between patients with below-knee DVT compared with above-knee DVT overall was not different (3.3% and 4.7%, p = 0.59). To assess DVT outcomes, 157 of the 308 patients had serial duplex studies following diagnosis of lower-extremity DVT. The number of patients receiving either therapeutic or prophylactic LMWH was similar (51% and 49%). There was no difference in rates of resolution or improvement between LMWH dosing groups or location of DVT. CONCLUSION In screened trauma patients, below-knee DVT is more common than above-knee DVT. There was no difference in the incidence of PE between groups. Standard prophylactic and therapeutic dosing of LMWH does not affect the rates of resolution or improvement of lower-extremity DVT. Rates of resolution and improvement of DVT is not dependent of location of lower-extremity DVT. LEVEL OF EVIDENCE Therapeutic study, level IV; epidemiologic study, level III.

BACKGROUND:We performed this study to optimize reconstituted lyophilized plasma (LP) into a minimal volume fluid that provides effective hemostatic resuscitation for trauma while minimizing logistical limitations. METHODS:We performed a prospective, blinded animal study. Plasma was lyophilized following whole blood collection from anesthetized swine. The minimal volume needed for reconstitution was determined, and this solution was evaluated for safe infusion into the swine. Reconstituted LP was analyzed for electrolyte content, osmolarity, and coagulation factor activity. Twenty swine were anesthetized and subjected to a validated model of polytrauma and hemorrhagic shock (including a Grade V liver injury), then randomized to resuscitation with LP reconstituted to either 100% of the original plasma volume (100%LP) or the minimal volume LP fluid. Physiologic data were monitored, and blood loss and hematocrit were measured. Coagulation status was evaluated using thrombelastography. RESULTS:The minimal volume of reconstituted LP safe for infusion in swine was 50% of the original plasma volume (50%LP). The 50%LP had higher electrolyte concentrations, osmolarity, and increased coagulation factor activity levels by volume compared with 100%LP (p < 0.05). Blood loss, hematocrit, mean arterial pressure, and heart rate did not differ between animals receiving 100%LP (n = 10) or 50%LP (n = 10) at any time point (p > 0.05). International normalized ratio and thrombelastography parameters were not different between groups (R time, α angle, or maximal amplitude, p > 0.05). CONCLUSION:Resuscitation with 50%LP fluid was well tolerated and equally effective compared with 100%LP, with respect to physiologic and hemostatic properties. The smaller volume of fluid necessary to reconstitute hypertonic LP makes it logistically superior to 100%LP for first responders and may reduce adverse effects of large-volume resuscitation.