Jon D. Simmons

Blood transfusion products contain mitochondrial DNA damage-associated molecular patterns: a potential effector of transfusion-related acute lung injury.

BACKGROUNDnTransfusion-related acute lung injury (TRALI) is the most frequent and severe complication in patients receiving multiple blood transfusions. Current pathogenic concepts hold that proinflammatory mediators present in transfused blood products are responsible for the initiation of TRALI, but the identity of the critical effector molecules is yet to be determined. We hypothesize that mtDNA damage-associated molecular patterns (DAMPs) are present in blood transfusion products, which may be important in the initiation of TRALI.nnnMETHODSnDNA was extracted from consecutive samples of packed red blood cells, fresh frozen plasma (FFP), and platelets procured from the local blood bank. Quantitative real-time polymerase chain reaction was used to quantify ≈200 bp sequences from the COX1, ND1, ND6, and D-loop regions of the mitochondrial genome.nnnRESULTSnA range of mtDNA DAMPs were detected in all blood components measured, with FFP displaying the largest variation.nnnCONCLUSIONSnWe conclude that mtDNA DAMPs are present in packed red blood cells, FFP, and platelets. These observations provide proof of the concept that mtDNA DAMPs may be mediators of TRALI. Further studies are needed to test this hypothesis and to determine the origin of mtDNA DAMPs in transfused blood.

Mitochondrial DNA damage-associated molecular patterns mediate a feed-forward cycle of bacteria-induced vascular injury in perfused rat lungs.

Fragments of the mitochondrial genome released into the systemic circulation after mechanical trauma, termed mitochondrial DNA damage-associated molecular patterns (mtDNA DAMPs), are thought to mediate the systemic inflammatory response syndrome. The close association between circulating mtDNA DAMP levels and outcome in sepsis suggests that bacteria also might be a stimulus for mtDNA DAMP release. To test this hypothesis, we measured mtDNA DAMP abundance in medium perfusing isolated rat lungs challenged with an intratracheal instillation of 5 × 10(7) colony-forming units of Pseudomonas aeruginosa (strain 103; PA103). Intratracheal PA103 caused rapid accumulation of selected 200-bp sequences of the mitochondrial genome in rat lung perfusate accompanied by marked increases in both lung tissue oxidative mtDNA damage and in the vascular filtration coefficient (Kf). Increases in lung tissue mtDNA damage, perfusate mtDNA DAMP abundance, and Kf were blocked by addition to the perfusion medium of a fusion protein targeting the DNA repair enzyme Ogg1 to mitochondria. Intra-arterial injection of mtDNA DAMPs prepared from rat liver mimicked the effect of PA103 on both Kf and lung mtDNA integrity. Effects of mtDNA and PA103 on Kf were also attenuated by an oligodeoxynucleotide inhibitor of Toll-like receptor 9 (TLR-9) by mitochondria-targeted Ogg1 and by addition of DNase1 to the perfusion medium. Collectively, these findings are consistent with a model wherein PA103 causes oxidative mtDNA damage leading to a feed-forward cycle of mtDNA DAMP formation and TLR-9-dependent mtDNA damage that culminates in acute lung injury.

The safety of low molecular-weight heparin after blunt liver and spleen injuries

BACKGROUNDnAnticoagulation is routinely administered to all trauma patients owing to the high incidence of venous thromboembolism (VTE). However, the timing of administration of anticoagulation is not clearly defined when patients have blunt spleen or liver injuries because of the perceived risk of hemorrhage with early administration.nnnMETHODSnA retrospective chart review was performed of all blunt trauma patients who sustained blunt liver and/or spleen injuries during the 5-year period from 2007 to 2011. Data were collected for all patients managed with nonoperative therapy for these injuries while also receiving routine prophylactic anticoagulation with low molecular-weight heparin. Patients were categorized based on the initiation of enoxaparin therapy after injury: early (<48xa0hours), intermediate (48 to 72xa0hours), and late (>72xa0hours). Primary and secondary outcomes were designated as need for operative or radiologic intervention secondary to spleen or liver hemorrhage, number of transfusions, and incidence of VTE.nnnRESULTSnThree hundred and twenty-eight patients were included. There were no enoxaparin-related hemorrhagic complications or hemorrhage necessitating operative intervention. Patients in the early, intermediate, and late groups received an average of .9, .93, and 1.55 units of blood, respectively. There was 1 pulmonary embolism in the early group, and there were 6 VTE complications in the late group (3 deep venous thromboses and 3xa0pulmonary embolisms).nnnCONCLUSIONSnThere are currently no standards for the initiation of prophylactic anticoagulation in trauma patients with blunt liver and spleen injuries. Early administration may be safe and reduce the incidence of thrombotic complications in patients with blunt spleen and liver injuries. Prospective studies in this area are warranted.

A Novel Classification System for Injuries After Electronic Cigarette Explosions.

Electronic cigarettes (e-cigarettes) contain lithium batteries that have been known to explode and/or cause fires that have resulted in burn injury. The purpose of this article is to present a case study, review injuries caused by e-cigarettes, and present a novel classification system from the newly emerging patterns of burns. A case study was presented and online media reports for e-cigarette burns were queried with search terms “e-cigarette burns” and “electronic cigarette burns.” The reports and injury patterns were tabulated. Analysis was then performed to create a novel classification system based on the distinct injury patterns seen in the study. Two patients were seen at our regional burn center after e-cigarette burns. One had an injury to his thigh and penis that required operative intervention after ignition of this device in his pocket. The second had a facial burn and corneal abrasions when the device exploded while he was inhaling vapor. The Internet search and case studies resulted in 26 cases for evaluation. The burn patterns were divided in direct injury from the device igniting and indirect injury when the device caused a house or car fire. A numerical classification was created: direct injury: type 1 (hand injury) 7 cases, type 2 (face injury) 8 cases, type 3 (waist/groin injury) 11 cases, and type 5a (inhalation injury from using device) 2 cases; indirect injury: type 4 (house fire injury) 7 cases and type 5b (inhalation injury from fire started by the device) 4 cases. Multiple e-cigarette injuries are occurring in the United States and distinct patterns of burns are emerging. The classification system developed in this article will aid in further study and future regulation of these dangerous devices.

Rib fractures and their association With solid organ injury: higher rib fractures have greater significance for solid organ injury screening

BACKGROUNDnThe purpose of this study was to identify patients with rib injuries who were at risk for solid organ injury.nnnMETHODSnA retrospective chart review was performed of all blunt trauma patients with rib fractures during the period from July 2007 to July 2012. Data were analyzed for association of rib fractures and solid organ injury.nnnRESULTSnIn all, 1,103 rib fracture patients were identified; 142 patients had liver injuries with 109 (77%) associated right rib fractures. Right-sided rib fractures with highest sensitivity for liver injury were middle rib segment (5 to 8) and lower segment (9 to 12) with liver injury sensitivities of 68% and 43%, respectively (P < .001); 151 patients had spleen injuries with 119 (79%) associated left rib fractures. Left middle segment rib fractures and lower segment rib fractures had sensitivities of 80% and 63% for splenic injury, respectively (P < .003).nnnCONCLUSIONSnRib fractures higher in the thoracic cage have significant association with solid organ injury. Using rib fractures from middle plus lower segments as indication for abdominal screening will significantly improve rib fracture sensitivity for identification of solid organ injury.

Role of Endovascular Grafts in Combined Vascular and Skeletal Injuries of the Lower Extremity: a Preliminary Report

Background A gunshot wound to the lower extremity with combined skeletal and vascular injuries can be difficult to manage. In clinical practice, it is not always possible to assemble a multispecialty team to work seamlessly to attain this goal, and the end result may be unnecessary prolonged ischemic time. A covered endovascular stent (EVS) can be used initially to restore perfusion without need of a time-consuming temporary shunt in select cases. Objectives The objective of this study is to compare novel methods of repairing the superficial femoral artery to the traditional three-step operative approach in patients that have a concomitant femur fracture. Patients and Methods All patients with combined vascular and skeletal injuries to the lower extremity were reviewed retrospectively. Patients were divided into three groups: Group 1: EVS placed percutaneously. Group 2: EVS placed with a hybrid combination of open and endovascular technique. Group 3: Placement of temporary shunt followed by skeletal stabilization and definitive vascular repair. Results There were 16 patients identified. Group 1 = three, Group 2 = six, Group 3 = seven. EVS can shorten time to revascularization and prevents a second episode of vascular interruption at the time of the final vascular repair. The structural stability of the EVS was strong enough to withstand the skeletal manipulation without deformation of the stent. Conclusions EVS is comparable to open repair and has the strength to withstand orthopedic manipulation in the short term when used in combined vascular and skeletal injuries to the lower extremity. Ischemic time is reduced significantly if final revascularization is accomplished at the onset with an EVS and the process is more efficient if the trauma surgeon is able to repair the vascular injury. With increasing sophistication of endovascular devices, this offers an appealing approach to vascular injuries that will decrease ischemic and total operative times when compared to the more traditional three-stage repair.

A Solution to the Decreased Resident Exposure to Open Operations in the Era of Minimally Invasive Surgery and Restricted Duty Hours May Be with Organ Procurement and Transplantation Surgery

INTRODUCTIONnThe surgical resident experience regarding open surgical procedures and techniques is being significantly limited by the maturation of minimally invasive surgery (MIS) and duty-hour restrictions. MIS has replaced many open procedures as the current standard of care. As MIS progresses, the surgical residents access to open surgical techniques will become significantly limited by the lack of exposure to common open operations.nnnMETHODSnThe Accreditation Council for Graduate Medical Education (ACGME) database was retrospectively reviewed to quantify and categorize resident experience in self-reported surgical procedures. The United Network for Organ Sharing (UNOS) database was retrospectively reviewed to determine the amount of organ transplants and procurements performed during the study period. Data from 1999-2000 and 2008-2009 were collected and compared.nnnRESULTSnThere were dramatic changes between the time periods regarding the transition from the open to the laparoscopic approach for multiple operations. In 2008, there were 23,276 transplanted organs and 29,077 organs procured (7990 multi-organ procurements). However, the graduating general surgery chief residents reported doing an average of 2 organ procurements and 7 organ transplantations over a 5-year period. This provides the opportunity for each graduating chief resident to perform 38 more procurements during their residency.nnnCONCLUSIONnIt is imperative for surgical educators to find solutions to safely train the future general surgery residents to perform more surgical techniques in less time. One solution to this problem may lie within the field of organ transplantation and procurement. The field of organ transplantation and procurement may be an untapped resource for valuable exposure to the basic principles of open surgical techniques that are declining due to the advancement of MIS and mandated duty-hour restrictions.

Larger ATV engine size correlates with an increased rate of traumatic brain injury

INTRODUCTIONnSince the introduction of all-terrain vehicles (ATV) to the United States in 1971, injuries and mortalities related to their use have increased significantly. Furthermore, these vehicles have become larger and more powerful. As there are no helmet requirements or limitations on engine-size in the State of Alabama, we hypothesised that larger engine size would correlate with an increased incidence of traumatic brain injury (TBI) in patients following an ATV crash.nnnMETHODSnPatient and ATV data were prospectively collected on all ATV crashes presenting to a level one trauma centre from September 2010 to May 2013. Collected data included: demographics, age of driver, ATV engine size, presence of helmet, injuries, and outcomes. The data were grouped according to the ATV engine size in cubic centimetres (cc). For the purposes of this study, TBI was defined as any type of intracranial haemorrhage on the initial computed tomography scan.nnnRESULTSnThere were 61 patients identified during the study period. Two patients (3%) were wearing a helmet at the time of injury. Patients on an ATV with an engine size of 350 cc or greater had higher Injury Severity Scores (13.9 vs. 7.5, p ≤ 0.05) and an increased incidence of TBI (26% vs. 0%, p ≤ 0.05) when compared to patients on ATVs with an engine size less than 350 cc.nnnCONCLUSIONSnPatients on an ATV with an engine size of 350 cc or greater were more likely to have a TBI. The use of a helmet was rarely present in this cohort. Legislative efforts to implement rider protection laws for ATVs are warranted.

The Combination of SAT and SBT Protocols May Help Reduce the Incidence of Ventilator-Associated Pneumonia in the Burn Intensive Care Unit

There are few published reports on the unique nature of burn patients using a paired spontaneous awakening and spontaneous breathing protocol. A combined protocol was implemented in our burn intensive care unit (ICU) on January 1, 2012. This study evaluates the impact of this protocol on patient outcomes in a burn ICU. We performed a retrospective review of our burn registry over 4 years, including all patients placed on mechanical ventilation. In the latter 2 years, patients meeting criteria underwent daily spontaneous awakening trial; if successful, spontaneous breathing trial was performed. Patient data included age, burn size, percent full-thickness burn, tracheostomy, and inhalation injury. Outcome measures included ventilator days, ICU and hospital lengths of stay, pneumonia, and disposition. Data were analyzed using Graphpad Prism and IBM SPSS software, with statistical significance defined as P < .05. There were 171 admissions in the preprotocol period and 136 after protocol implementation. Protocol patients had greater percent full-thickness burns, but did not differ in other characteristics. The protocol group had significantly shorter ICU length of stay, fewer ventilator days, and lower pneumonia incidence. Hospital length of stay, disposition, and mortality were not significantly different. Among patients with inhalation injuries, the protocol group exhibited fewer ventilator and ICU days. Protocol implementation in a burn ICU was accompanied by decreased ventilator days and a reduced incidence of pneumonia. A combined spontaneous awakening and breathing protocol is safe and may improve clinical practice in the burn ICU.

Intraoperative management of renal gunshot injuries: is mandatory exploration of Gerota’s fascia necessary?

BACKGROUNDnMany trauma surgeons and trauma centers use routine exploration of Gerotas fascia (GE) for renal gunshot wounds (RGSW). The purpose of this study was to assess whether RGSW can be selectively explored for patients who undergo exploratory laparotomy.nnnMETHODSnRetrospective 10-year review of all patients who underwent exploratory laparotomy for abdominal gunshot wounds and had RGSW selectively explored.nnnRESULTSnSixty-three patients with RGSW underwent exploratory laparotomy. Twenty-eight (44%) underwent GE vs 35 (56%) who did not. Eight (29%) mortalities occurred with GE and 5 (14%) without GE (P < .05). Of GE patients, 14 (50%) had nephrectomy and 14 (50%) had renorrhaphy. Average hospital length of stay with GE was 16.7xa0days vs 17.9 without GE. Three (9%) renal-associated complications occurred without GE and 1 (4%) with GE.nnnCONCLUSIONSnMost patients who suffer RGSW do not require exploration of GE during abdominal exploration. Complication rates due to nonexploration of RGSW are very low with infrequent need for surgical intervention due to renal-associated complications. High nephrectomy rates may be avoided when GE is averted.