Andrew J. Dennis

CT should replace three-view radiographs as the initial screening test in patients at high, moderate, and low risk for blunt cervical spine injury: a prospective comparison.

BACKGROUND An estimated 10,000 Americans suffer cervical spine injuries each year. More than 800,000 cervical spine radiographs (CSR) are ordered annually. The human and healthcare costs associated with these injuries are enormous especially when diagnosis is delayed. Controversy exists in the literature concerning the diagnostic accuracy of CSR, with reported sensitivity ranging from 32% to 89%. We sought to compare prospectively the sensitivity of cervical CT (CCT) to CSR in the initial diagnosis of blunt cervical spine injury for patients meeting one or more of the NEXUS criteria. METHODS The study prospectively compared the diagnostic accuracy of CSR to CCT in consecutive patients evaluated for blunt trauma during 23 months at an urban, public teaching hospital and Level I Trauma Center. Inclusion criteria were adult patient, evaluated for blunt cervical spine injury, meeting one or more of the NEXUS criteria. All patients received both three-view CSR and CCT as part of a standard diagnostic protocol. Each CSR and CCT study was interpreted independently by a different radiology attending who was blinded to the results of the other study. Clinically significant injuries were defined as those requiring one or more of the following interventions: operative procedure, halo application, and/or rigid cervical collar. RESULTS Of 1,583 consecutive patients evaluated for blunt cervical spine trauma, 78 (4.9%) patients received only CCT or CSR and were excluded from the study. Of the remaining 1,505 patients, 78 (4.9%) had evidence of a radiographic injury by CSR or CCT. Of these 78 patients with radiographic injury, 50 (3.3%) patients had clinically significant injuries. CCT detected all patients with clinically significant injuries (100% sensitive), whereas CSR detected only 18 (36% sensitive). Of the 50 patients, 15 were at high risk, 19 at moderate risk, and 16 at low risk for cervical spine injury according to previously published risk stratification. CSR detected clinically significant injury in 7 high risk (46% sensitive), 7 moderate risk (37% sensitive), and 4 low risk patients (25% sensitive). CONCLUSION Our results demonstrate the superiority of CCT compared with CSR for the detection of clinically significant cervical spine injury. The improved ability to exclude injury rapidly provides further evidence that CCT should replace CSR for the initial evaluation of blunt cervical spine injury in patients at any risk for injury.

TASER X26 Discharges in Swine Produce Potentially Fatal Ventricular Arrhythmias

OBJECTIVES Data from the authors and others suggest that TASER X26 stun devices can acutely alter cardiac function in swine. The authors hypothesized that TASER discharges degrade cardiac performance through a mechanism not involving concurrent acidosis. METHODS Using an Institutional Animal Care and Use Committee (IACUC)-approved protocol, Yorkshire pigs (25-71 kg) were anesthetized, paralyzed with succinylcholine (SCh; 2 mg/kg), and then exposed to two 40-second discharges from a TASER X26 with a transcardiac vector. Vital signs, blood chemistry, and electrolyte levels were obtained before exposure and periodically for 48 hours postdischarge. Electrocardiograms and echocardiography (echo) were performed before, during, and after the discharges. p-Values < 0.05 were considered significant. RESULTS Electrocardiograms were unreadable during the discharges due to electrical interference, but echo images showed unmistakably that cardiac rhythm was captured immediately at a rate of 301 +/- 18 beats/min (n = 8) in all animals tested. Capture continued for the duration of the discharge and in one animal degenerated into fatal ventricular fibrillation (VF). In the remaining animals, ventricular tachycardia (VT) occurred postdischarge for 1-17 seconds, whereupon sinus rhythm was regained spontaneously. Blood chemistry values and vital signs were minimally altered postdischarge and no significant acidosis was seen. CONCLUSIONS Extreme acid-base disturbances usually seen after lengthy TASER discharges were absent with SCh, but TASER X26 discharges immediately and invariably produced myocardial capture. This usually reverted spontaneously to sinus rhythm postdischarge, but fatal VF was seen in one animal. Thus, in the absence of systemic acidosis, lengthy transcardiac TASER X26 discharges (2 x 40 seconds) captured myocardial rhythm, potentially resulting in VT or VF in swine.

Taser X26 Discharges in Swine: Ventricular Rhythm Capture is Dependent on Discharge Vector

BACKGROUND Data from our previous studies indicate that Taser X26 stun devices can acutely alter cardiac function in swine. We hypothesized that most transcardiac discharge vectors would capture ventricular rhythm, but that other vectors, not traversing the heart, would fail to capture the ventricular rhythm. METHODS Using an Institutional Animal Care and Use Committee (IACUC) approved protocol, four Yorkshire pigs (25-36 kg) were anesthetized, paralyzed with succinylcholine (2 mg/kg), and then exposed to 10 second discharges from a police-issue Taser X26. For most discharges, the barbed darts were pushed manually into the skin to their full depth (12 mm) and were arranged in either transcardiac (such that a straight line connecting the darts would cross the region of the heart) or non-transcardiac vectors. A total of 11 different vectors and 22 discharge conditions were studied. For each vector, by simply rotating the cartridge 180-degrees in the gun, the primary current-emitting dart was changed and the direction of current flow during the discharge was reversed without physically moving the darts. Echocardiography and electrocardiograms (ECGs) were performed before, during, and after all discharges. p values < 0.05 were considered significant. RESULTS ECGs were unreadable during the discharges because of electrical interference, but echocardiography images clearly demonstrated that ventricular rhythm was captured immediately in 52.5% (31 of 59) of the discharges on the ventral surface of the animal. In each of these cases, capture of the ventricular rhythm with rapid ventricular contractions consistent with ventricular tachycardia (VT) or flutter was seen throughout the discharge. A total of 27 discharges were administered with transcardiac vectors and ventricular capture occurred in 23 of these discharges (85.2% capture rate). A total of 32 non-transcardiac discharges were administered ventrally and capture was seen in only eight of these (25% capture rate). Ventricular fibrillation (VF) was seen with two vectors, both of which were transcardiac. In the remaining animals, VT occurred postdischarge until sinus rhythm was regained spontaneously. CONCLUSIONS For most transcardiac vectors, Taser X26 caused immediate ventricular rhythm capture. This usually reverted spontaneously to sinus rhythm but potentially fatal VF was seen with two vectors. For some non-transcardiac vectors, capture was also seen but with a significantly (p < 0.0001) decreased incidence.

Screening for traumatic stress among survivors of urban trauma.

OBJECTIVE This study piloted the use of the Primary Care PTSD (PC-PTSD) screening tool in an outpatient setting to determine its utility for broader use and to gather data on traumatic stress symptoms among direct (patients) and indirect (families) survivors of traumatic injuries. METHODS Using the PC-PTSD plus one question exploring openness to seeking help, participants were screened for PTSD in the outpatient clinic of an urban Level 1 trauma center. The survey was distributed during a 23-week period from April to September 2011. The screen was self-administered, a sample of convenience, and participation was voluntary and anonymous. RESULTS With a response rate of 66%, 307 surveys were completed. Forty-two percent of participants had a positive screen. Patients greater than 30 and 90 days from injury had 1.5 and 1.7 times more positive screens than those less than 30 days. Patients with gunshot wounds were 13 times as likely as those with falls and twice as likely as those in a motor vehicle crash to have a positive screen. Sixty percent of patients with a positive screen noted it would be helpful to talk to someone. CONCLUSION The PC-PTSD was an easy to administer screening tool. Patients reported PTSD symptoms at higher rates than previous studies. Patients with gunshot wounds and those injured greater than 30 days from the time of the screen were more likely to report PTSD symptoms. Although males represented 82% of positive screens, there was no statistical difference in PTSD symptoms between male and female participants because of the small number of females represented. Families also reported significant levels of PTSD. Both patients and families may benefit from additional screening and intervention in the early posttrauma period. LEVEL OF EVIDENCE Epidemiologic study, level IV.

Not so fast to skin graft: Transabdominal wall traction closes most ''domain loss'' abdomens in the acute setting

BACKGROUND Damage-control laparotomy (DCL) has revolutionized the surgery of injury. However, this has led to the dilemma of the nonclosable abdomen. Subsequently, there exists a subgroup of patients who after resuscitation and diuresis, remain nonclosable. Before the adoption of our open abdomen protocol (OAP) and use of transabdominal wall traction (TAWT), these patients required skin grafting and a planned ventral hernia. We hypothesize that our OAP and TAWT device, which use full abdominal wall thickness sutures to dynamically distribute midline traction, achieve an improved method of fascial reapproximation. METHODS From 2008 to 2011, all DCL and decompressive laparotomy patients in our urban trauma center were managed by our OAP. Thirty two were noncloseable “domain loss abdomens” after achieving physiologic steady state and near dry weight. All patients received the TAWT device when near dry weight was achieved. Wound size, days to closure, days to TAWT, and TAWT to closure were tracked. RESULTS During this 36-month period, OAP/TAWT was applied to 32 patients. All patients demonstrated domain loss precluding fascial closure. Average wound size was 18.5-cm width by 30.5-cm length. Mean time DCL surgery to TAWT was 9.5 days. At time of placement, TAWT decreased initial wound width by an average of 9.8 cm (51.4%). Patients returned to the operating room for tightening/washout an average of 2.2 times (excluding TAWT insertion and final closure operations). Mean time TAWT to closure was 8.7 days. Mean time from admission surgery to primary closure was 18.2 days. All patients achieved primary fascial closure using this method without components separation or biologic bridge operations. CONCLUSION OAP/TAWT has revolutionized the way we manage “domain loss” open abdomen patients and has virtually eliminated the acceptance of planned ventral hernia. TAWT consistently recaptures lost domain, preserves the leading fascial edge, and eliminates the need for biologic bridges, components separation, or skin grafting. LEVEL OF EVIDENCE Therapeutic study, level III.

Acute Effects of MK63 Stun Device Discharges in Miniature Swine

OBJECTIVE Electromuscular incapacitation (EMI) devices are being used and evaluated by both military and law enforcement agencies. Although the gross muscular response is obvious, physiological responses to these devices are poorly understood. We hypothesized that the intense, repetitive, muscle contractions evoked by EMI devices would cause dose-dependent metabolic acidosis, accompanied by neuromuscular or cardiac injury. METHODS Using an approved protocol, 26 Yucatan mini-pigs (22 experimental animals and 4 control animals) were anesthetized with ketamine and xylazine. Experimental animals were exposed to MK63 (Aegis Industries, Bellevue, Idaho) discharges over the left anterior hind limb for 10, 20, 40, or 80 seconds. Electrocardiograms, electromyograms, troponin I levels, blood gas values, and electrolyte levels were recorded before and 5, 15, 30, and 60 minutes and 24, 48, and 72 hours after discharge. Skin, muscle, and nerve biopsies were taken from the shocked and contralateral sides. RESULTS Core body temperature significantly decreased (1.0-1.5 degrees C) in all shocked animals but not in sham-treated control animals. No cardiac dysrhythmias or deaths were seen, and heart rate was unaffected. No clinically significant changes were seen in troponin I, myoglobin, or creatine kinase-MB levels. Central venous blood pH decreased, whereas carbon dioxide pressure and lactate levels increased for 60 minutes after discharge. All values returned to normal by 24 hours after discharge, and no significant histological or electromyographic changes were found. CONCLUSIONS Changes in blood chemistry were observed but were of little clinical significance, and no neuromuscular damage was detected. Therefore, within the limitations of this model, it appears that EMI can safely be achieved by using this device, even for lengthy periods, without causing significant injury.

Hemorrhage Control by Law Enforcement Personnel: A Survey of Knowledge Translation From the Military Combat Experience

BACKGROUND Military data demonstrate that exsanguinating hemorrhage is the leading cause of potentially preventable combat death. The purpose of this study was to evaluate attitudes and approaches of civilian law enforcement personnel in the management of acute hemorrhagic trauma. METHODS Anonymous survey administered via an online distribution mechanism. RESULTS 1,317 U.S. law enforcement personnel began the survey. 370 respondents (30.4%) reported their agencies issued tourniquets, whereas 48.8% indicated their agencies had provided specific training in tourniquet application. Pressure dressings were provided to 43.6% of respondents while hemostatic agents were available to 29.8%. Tourniquets were considered the intervention most likely to save a life, but were also deemed most likely to possibly cause harm or injury if used inappropriately. 43 respondents (0.036%) stated they were aware of circumstances within the past year in which an officer in their agency sustained injuries where a tourniquet could have been used, but was not. CONCLUSIONS Hemorrhage control supplies are being issued to less than half of the responding officers. When used, these interventions were generally thought to be effective. Further study is needed to delineate specific medical interventions, and therefore training and equipment, needed by law enforcement personnel.

Trans-abdominal wall traction as a universal solution to the management of giant ventral hernias.

Background: Domain loss following damage-control laparotomy is a challenging problem many surgeons face. The authors recently developed trans–abdominal wall traction, which closed 100 percent of domain loss abdomens in the acute setting. They hypothesized that it can be used successfully in patients with chronic giant ventral defects. Methods: From 2008 to 2013, 44 patients with acute loss of domain and 10 with chronically giant ventral defects were enrolled in the open abdomen protocol with subsequent placement of the trans–abdominal wall traction device. Results: Patients’ average age in the acute and chronic groups was 28.2 and 35.3 years and average body mass index was 26.4 and 32.4 kg/m2, respectively. Ventral hernia size was reduced with the first trans–abdominal wall traction insertion from 610.5 cm2 to 274.6 cm2 in the acute setting and from 598 cm2 to 236.9 cm2 in the chronic setting. Average time from damage-control laparotomy to device insertion was 12.9 days in the acute group and more than 3 years in the chronic group. Lost domain was achieved with an average of less than 2.5 trans–abdominal wall traction tightenings, correlating to 9.2 and 8.2 days in the acute and chronic groups, respectively. Enterocutaneous fistula occurrence was 9 percent in the acute group and 0 percent in the chronic group. Conclusions: All patients were successfully closed after reestablishment of the lost domain. Trans–abdominal wall traction is an effective means of reestablishing abdominal domain and achieving primary abdominal wall closure in all patients with giant ventral defects, both acute and chronic. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Placenta to the Rescue: Limb Salvage Using Dehydrated Human Amnion/Chorion Membrane

Reconstruction of skin and soft tissue wounds can pose a unique surgical challenge. This is especially true for cases of exposed bone and tendon where soft tissue loss is extensive and opportunities for tissue advancement or rotation are limited. A clinical case is presented describing an experience with dehydrated human amnion/chorion membrane (dHACM, EpiFix®/AmnioFix®, MiMedx Group, Marietta, GA) graft to obtain granulation over an open fracture with desiccated bone. The 22-year-old female trauma patient presented with high-grade bilateral lower extremity soft tissue loss after being run over and dragged by a semitruck. Despite several weeks of serial debridemonts, the right distal fibula and left medial femur remained desiccated and infected. Both extremities had cavernous tissue landscapes with minimal granulation tissue and neither was hospitable for split thickness skin grafting. Four separate applications of dHACM (combination of EpiFix® and AmnioFix®) to the affected areas of exposed bone were successful at stimulating a robust granulation bed. On hospital days 44 and 61, the wounds were successfully skin grafted. The authors suspect that the dHACM applications contributed to successful granulation coverage to the affected bones that were otherwise not amendable to other coverage options. This contributed to limb salvage and a successful outcome.