Dysregulation of the actin scavenging system and inhibition of DNase activity following severe thermal injury

Background

Circulating cell‐free DNA (cfDNA) is not found in healthy subjects, but is readily detected after thermal injury and may contribute to the risk of multiple organ failure. The hypothesis was that a postburn reduction in DNase protein/enzyme activity could contribute to the increase in cfDNA following thermal injury.

Methods

Patients with severe burns covering at least 15 per cent of total body surface area were recruited to a prospective cohort study within 24 h of injury. Blood samples were collected from the day of injury for 12 months.

Results

Analysis of blood samples from 64 patients revealed a significant reduction in DNase activity on days 1–28 after injury, compared with healthy controls. DNase protein levels were not affected, suggesting the presence of an enzyme inhibitor. Further analysis revealed that actin (an inhibitor of DNase) was present in serum samples from patients but not those from controls, and concentrations of the actin scavenging proteins gelsolin and vitamin D‐binding protein were significantly reduced after burn injury. In a pilot study of ten military patients with polytrauma, administration of blood products resulted in an increase in DNase activity and gelsolin levels.

Conclusion

The results of this study suggest a novel biological mechanism for the accumulation of cfDNA following thermal injury by which high levels of actin released by damaged tissue cause a reduction in DNase activity. Restoration of the actin scavenging system could therefore restore DNase activity, and reduce the risk of cfDNA‐induced host tissue damage and thrombosis.

Gun-shot injuries in UK military casualties - Features associated with wound severity

INTRODUCTION

Surgical treatment of high-energy gun-shot wounds (GSWs) to the extremities is challenging. Recent surgical doctrine states that wound tracts from high-energy GSWs should be laid open, however the experience from previous conflicts suggests that some of these injuries can be managed more conservatively. The aim of this study is to firstly characterise the GSW injuries sustained by UK forces, and secondly test the hypothesis that the likely severity of GSWs can be predicted by features of the wound.

METHODS

The UK Military trauma registry was searched for cases injured by GSW in the five years between 01 January 2009 and 31 December 2013: only UK personnel were included. Clinical notes and radiographs were then reviewed. Features associated with energy transfer in extremity wounds in survivors were further examined with number of wound debridements used as a surrogate marker of wound severity.

RESULTS

There were 450 cases who met the inclusion criteria. 96 (21%) were fatally injured, with 354 (79%) surviving their injuries. Casualties in the fatality group had a median New Injury Severity Score (NISS) of 75 (IQR 75-75), while the median NISS of the survivors was 12 (IQR 4-48) with 10 survivors having a NISS of 75. In survivors the limbs were most commonly injured (56%). 'Through and through' wounds, where the bullet passes intact through the body, were strongly associated with less requirement for debridement (p<0.0001). When a bullet fragmented there was a significant association with a requirement for a greater number of wound debridements (p=0.0002), as there was if a bullet fractured a bone (p=0.0006).

CONCLUSIONS

More complex wounds, as indicated by the requirement for repeated debridements, are associated with injuries where the bullet does not pass straight through the body, or where a bone is fractured. Gunshot wounds should be assessed according to the likely energy transferred, extremity wounds without features of high energy transfer do not require extensive exploration.

Medium-term outcomes following limb salvage for severe open tibia fracture are similar to trans-tibial amputation

Extremity injuries define the surgical burden of recent conflicts. Current literature is inconclusive when assessing the merits of limb salvage over amputation. The aim of this study was to determine medium term functional outcomes in military casualties undergoing limb salvage for severe open tibia fractures, and compare them to equivalent outcomes for unilateral trans-tibial amputees. Cases of severe open diaphyseal tibia fractures sustained in combat between 2006 and 2010, as described in a previously published series, were contacted. Consenting individuals conducted a brief telephone interview and were asked to complete a SF-36 questionnaire. These results were compared to a similar cohort of 18 military patients who sustained a unilateral trans-tibial amputation between 2004 and 2010. Forty-nine patients with 57 severe open tibia fractures met the inclusion criteria. Telephone follow-up and SF-36 questionnaire data was available for 30 patients (61%). The median follow-up was 4 years (49 months, IQR 39-63). Ten of the 30 patients required revision surgery, three of which involved conversion from initial fixation to a circular frame for non- or mal-union. Twenty-two of the 30 patients (73%) recovered sufficiently to complete an age-standardised basic military fitness test. The median physical component score of SF-36 in the limb salvage group was 46 (IQR 35-54) which was similar to the trans-tibial amputation cohort (p=0.3057, Mann-Whitney). Similarly there was no difference in mental component scores between the limb salvage and amputation groups (p=0.1595, Mann-Whitney). There was no significant difference in the proportion of patients in either the amputation or limb salvage group reporting pain (p=0.1157, Fisher's exact test) or with respect to SF-36 physical pain scores (p=0.5258, Mann-Whitney). This study demonstrates that medium term outcomes for military patients are similar following trans-tibial amputation or limb salvage following combat trauma.

An evaluation of the normal range of StO₂measurements at rest and following a mixed exercise protocol

BACKGROUND

Assessment of local tissue oxygenation (StO₂) using near infrared spectroscopy is an emerging technique in medical practice with applications in trauma/sepsis management, diagnosis of acute compartment syndrome and assessment of tissue viability. Despite this, there have been little published data on the range of StO₂values in normal subjects.

METHODS

StO₂measurements were recorded in 105 infantry soldiers using an INVOS System Monitor (Somanetics) from both deltoids, the anterior compartment of the leg and the frontal lobe of the brain. Measurements were taken at rest and following completion of a mixed exercise protocol, consisting of overarm pull-ups, sit-ups and a 3-mile run.

RESULTS

StO₂values at rest were found to have a wide normal range with a skew left distribution. Mean StO₂was similar between the deltoids (left deltoid 80%, right deltoid 79%), but significantly different between other anatomical sites (leg 68%, brain 73%). However, all sites demonstrated a similar lower range cut-off at approximately 40%. Following exercise, there was a significant increase in StO₂values at all sites (left deltoid by 3.1 ± 2.0%, right deltoid by 2.6 ± 2.3%, leg by 8.0 ± 2.3% and brain by 8.6 ± 1.9%), which persisted for at least 10 min.

CONCLUSIONS

There were statistically significant differences in mean StO₂values recorded at different anatomical sites, although the reference ranges were wide and substantially overlapped. StO₂increased at all sites after exercise with the effect persisting for at least 10 min. The interaction between exercise and pathological phenomena remains unknown and is an area for further study.

Acute bilateral leg amputation following combat injury in UK servicemen

BACKGROUND

This study aims to characterise the injuries and surgical management of British servicemen sustaining bilateral lower limb amputations.

METHODS

The UK Military Trauma Registry was searched for all cases of primary bilateral lower limb amputation sustained between March 2004 and March 2010. Amputations were excluded if they occurred more than 7 days after injury or if they were at the ankle or more distal.

RESULTS

There were 1694 UK military patients injured or killed during this six-year study period. Forty-three of these (2.8%) were casualties with bilateral lower limb amputations. All casualties were men with a mean age of 25.1 years (SD 4.3): all were injured in Afghanistan by Improvised Explosive Devices (IEDs). Six casualties were in vehicles when they were injured with the remaining 37 (80%) patrolling on foot. The mean New Injury Severity Score (NISS) was 48.2 (SD 13.2): four patients had a maximum score of 75. The mean TRISS probability of survival was 60% (SD 39.4), with 18 having a survival probability of less than 50% i.e. unexpected survivors. The most common amputation pattern was bilateral trans-femoral (TF) amputations, which was seen in 25 patients (58%). Nine patients also lost an upper limb (triple amputation): no patients survived loss of all four limbs. In retained upper limbs extensive injuries to the hands and forearms were common, including loss of digits. Six patients (14%) sustained an open pelvic fracture. Perineal/genital injury was a feature in 19 (44%) patients, ranging from unilateral orchidectomy to loss of genitalia and permanent requirement for colostomy and urostomy. The mean requirement for blood products was 66 units (SD 41.7). The maximum transfusion was 12 units of platelets, 94 packed red cells, 8 cryoprecipitate, 76 units of fresh frozen plasma and 3 units of fresh whole blood, a total of 193 units of blood products.

CONCLUSIONS

Our findings detail the severe nature of these injuries together with the massive surgical and resuscitative efforts required to firstly keep patients alive and secondly reconstruct and prepare them for rehabilitation.

Outcome of penetrating intracranial injuries in a military setting

BACKGROUND

Penetrating intracranial injuries are common in the deployed military medical environment. Early assessment of prognosis includes initial conscious level. There has been no previous identification of different outcomes depending on mechanism of penetrating injury. The aim of this study was to define outcome from penetrating head injury in our population, and to compare outcome between gunshot wound (GSW) and blast fragment injury, in order to detect a difference in survival.

METHODS

A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry (JTTR) between the dates 2003 and 2011 to identify all cases of penetrating head injury. Data collected included mechanism of injury, first recorded GCS, injury severity score (ISS), abbreviated injury scale (AIS) head score, concomitant extracranial injury, surgical intervention, hospital length of stay, and survival.

RESULTS

813 patients sustained a penetrating head injury, of whom 625 were injured by blast fragmentation and 188 were injured by GSW; overall 336 patients (41.3%) died. There was a significant difference between survival from GSW (41.5%) and blast fragment (63.8%; p<0.001). In addition, the GCS in patients injured by GSW was significantly lower than that in patients injured by blast fragment. 157 cases sustained isolated head injury (79 GSW, 78 blast). The difference in injury severity between these groups was marked; median AIS was higher in the GSW group, survival lower (42% vs. 88%; p<0.001) and distribution of GCS categories less favourable (p<0.001). 338 of 343 patients (98.5%) with a best recorded GCS>5, survived to discharge.

CONCLUSION

Most patients who present following penetrating intracranial injury, who have a GCS>5, survive to discharge. There is a significant difference in survival to hospital discharge following penetrating injury caused by blast fragment compared to those caused by GSW, partly attributable to a difference in injury severity. This is the first study to specifically highlight and define this difference.

Damage control - trauma care in the first hour and beyond: a clinical review of relevant developments in the field of trauma care

INTRODUCTION

Trauma provision in the UK is a topic of interest. Regional trauma networks and centres are evolving and research is blossoming, but what bearing does all this have on the care that is delivered to the individual patient? This article aims to provide an overview of key research concepts in the field of trauma care, to guide the clinician in decision making in the management of major trauma.

METHODS

The Ovid MEDLINE(®), EMBASE™ and PubMed databases were used to search for relevant articles on haemorrhage control, damage control resuscitation and its exceptions, massive transfusion protocols, prevention and correction of coagulopathy, acidosis and hypothermia, and damage-control surgery.

FINDINGS

A wealth of research is available and a broad range has been reviewed to summarise significant developments in trauma care. Research has been categorised into disciplines and it is hoped that by considering each, a tailored management plan for the individual trauma patient will evolve, potentially improving patient outcome.

Utility of interim ROTEM(®) values of clot strength, A5 and A10, in predicting final assessment of coagulation status in severely injured battle patients

BACKGROUND

Proactive management of trauma-related coagulopathy requires early identification and rapid assessment in order to allow targeted resuscitation. This study determined whether early (interim) ROTEM(®) (TEM International GmbH, Munich, Germany) values could predict hypocoagulopathy in seriously injured military patients.

METHODS

Normal ranges for ROTEM(®) values were obtained from 50 volunteers. 108 samples were collected during the early phase of clinical management from 48 severe trauma patients. The blood was subject to EXTEM analysis and compared to the 95% tolerance limits from the volunteers. Coagulopathy (was deemed to be present if EXTEM MCF was below 40 mm, which is in the range indicating clinical concern defined by the ROTEM(®) Expert Working Group.

RESULTS

The normal range data was broadly similar to ROTEM(®) published data. Admission samples were available from 31 battlefield casualties, and 39% of these were coagulopathic 51% of the samples from all 48 patients were coagulopathic (EXTEM MCF<40 mm) and interim EXTEM values of these at 5 and 10 min (A5 and A10) predicted coagulopathy with sensitivities/specificities of 0.96/0.58 (A5) and 1.00/0.70 (A10). In addition, statistical comparison of clotting domains between normal volunteers and trauma patients suggests a difference in clot strengths due to a difference in platelet function rather than platelet number (mean 142 × 10(9)l(-1)).

CONCLUSIONS

The A10 value of ROTEM(®) provides an early sensitive and specific assessment of coagulopathy after military trauma and may be of utility in guiding bespoke resuscitation. We found some speculative evidence that in major trauma platelet function is particularly affected.

Conducting clinical research in the deployed intensive care unit: challenges and solutions

Conducting research in the deployed environment is challenging but if the various obstacles are overcome then the data captured can be vital in developing future treatment strategies. Perhaps the most important aspect is having an enthusiastic individual who is dedicated to research and can thus concentrate on maximising the potential of this unique environment.

The clinical outcome of UK military personnel who received a massive transfusion in Afghanistan during 2009

OBJECTIVES

The UK Defence Medical Services has developed a Massive Transfusion Protocol (MTP) that forms part of the initial Damage Control Resuscitation process for severely injured combat casualties. The key objectives of this retrospective review of MTP recipients are to document the survival rates, level of critical care support required and the blood components transfused as part of the Massive Transfusion Protocol in Afghanistan during 2009. In addition to providing a measure of our current effectiveness it should also provide a reference point for future reviews as the MTP continues to evolve.

METHODS

This was a collaborative project involving the Royal Centre for Defence Medicine and the Critical Care Department, University Hospitals Birmingham. It was limited to UK military personnel who were injured in 2009 and received massive transfusions (defined as the transfusion of 10 or more units of packed red blood cells over a 24-hour period) at Camp Bastion Role 3 Medical Facility, Afghanistan.

RESULTS

During the 12-month period, 59 personnel received massive transfusions. 51 (86%) personnel survived to be discharged from hospital in the UK. 48 (92%) personnel required ventilatory support for a median of 3 (2-8) days. The longest period of ventilation was 40 days; 29 (55%) personnel required vasopressor support and eight personnel (15%) required renal replacement therapy. The median total transfusion of blood components was 45 (28.5-62) units. There were seven transfusions of more than 100 units. Five of the personnel in this group (including the recipient of a 237-unit transfusion) survived to be discharged from University Hospitals Birmingham. On average, 1.21 (SD 0.28) units of packed red blood cells were transfused for every unit of fresh frozen plasma.

CONCLUSIONS

The use of the current MTP was associated with a high rate of survival. Survivors require a continuity of critical care with a median demand for 3 days. The early use of plasma and platelets can be successfully delivered in the battlefield despite operational and logistic constraints.

Associated injuries in casualties with traumatic lower extremity amputations caused by improvised explosive devices

BACKGROUND

Improvised explosive devices (IEDs) pose a significant threat to military personnel, often resulting in lower extremity amputation and pelvic injury. Immediate management is haemorrhage control and debridement, which can involve lengthy surgery. Computed tomography is necessary to delineate the extent of the injury, but it is unclear whether to perform this during or after surgery.

METHODS

The UK Joint Theatre Trauma Registry was searched to identify all UK service personnel who had a traumatic lower extremity amputation following IED injury between January 2007 and December 2010. Data were collected on injury pattern and survival.

RESULTS

There were 169 patients who sustained 278 traumatic lower extremity amputations: 69 were killed in action, 16 died from their wounds and 84 were wounded in action, but survived. The median (interquartile range) Injury Severity Score was 75 (21) for those killed in action, 46 (23) for those who died from wounds and 29 (12) for survivors. There were significantly more severe head, chest and abdominal injuries (defined as a body region Abbreviated Injury Scale score of 3 or more) in patients who were killed in action than in those reaching hospital (P < 0·001). Hindquarter amputations were the most lethal, with a mortality rate of 95 per cent. Of the 100 casualties who reached hospital alive, there were nine thoracotomies, one craniotomy and 34 laparotomies. All head or torso injuries that required immediate operation were clinically apparent on admission.

CONCLUSION

Higher levels of amputation were associated with greater injury burden and mortality. Intraoperative computed tomography had little value in identifying clinically significant covert injuries.

Is pre-hospital thoracotomy necessary in the military environment?

INTRODUCTION

Exsanguination from penetrating torso injury is a major source of mortality on the battlefield. Advanced Life Support guidelines suggest 'on-scene' thoracotomy for patients in cardiac arrest following penetrating chest trauma. This requires significant resourcing and training. Experience from published series (31 pre-hospital thoracotomies with 3 survivors) suggests that when this manoeuvre is applied to a well selected group it is a significant and life-saving procedure. Can this be applied to military injuries?

METHODS

Over a 12 month period on Operation Herrick all patients who sustained significant thoracic trauma were retrospectively reviewed. Parameters were recorded to allow detailed analysis of injury pattern and operative management. Our main objective was to determine if an early (pre-hospital) thoracotomy would have influenced the outcome.

RESULTS

Over the period, 81 patients required operative intervention following thoracic trauma: 8 patients underwent emergency thoracotomy (performed as part of the resuscitation) and 14 underwent urgent thoracotomy (performed after physiology partly restored). There were 9 fatalities--7 undergoing emergency thoracotomy and 2 post-operatively from multi-organ failure. Of the 7 intra-operative deaths 4/7 patients had thoracic injury and 6/7 had additional abdominal injuries. The median predicted survival of fatalities was 2.0% using Trauma Injury Severity Scoring.

DISCUSSION

Emergency thoracotomy should be performed in cardiac arrest following penetrating trauma as soon as possible. Highest survival rates in both in-hospital and pre-hospital thoracotomy are found in isolated cardiac stab wounds (19.4%). Poorest survival is found in multiply, ballistic injured patients (0.7%). The latter best reflects the injury pattern of military patients who have cardiac arrest following penetrating torso injury.

CONCLUSION

As our injury pattern suggests, any pre-hospital thoracotomy on military patients is likely to require complex intervention in very challenging environments. Our evidence does not support the notion that earlier thoracotomy could improve survival.

Optimal clinical timelines--a consensus from the academic department of military surgery and trauma

There are no published studies directly addressing the issue of what is an acceptable timeline from point of wounding to surgical intervention within the military context. The proximal threshold has previously been determined by personal opinion, tactical, logistic and practical imperatives rather than by clinical demands. The aim of this paper is to review all relevant military and civilian studies where timelines have been quoted and to reach a number of unambiguous consensus statements to state the perceived ideal upper limits from point of wounding to holistic and realistic surgical care in modern war. An injured casualty should be transferred to an appropriate surgeon in an appropriate facility in as short a time from wounding as practical. It is clear that the best trauma surgery is performed in large, well resourced, well-supplied, air-conditioned hospitals. Current advances aimed to stretch timelines from wounding to surgical intervention are exciting and hold potential but remain scientifically unproven and are currently without any firm evidence base. Further critical research is therefore necessary. The effect of pre-hospital haemostatic resuscitation, provided by the enhanced Medical Emergency Response Team (MERTe) on patient outcome and effective timelines is currently unknown and unproven: it does have intuitive medical merit. There is also a very significant moral and morale component. MERTe serves two main functions; reduction in time from point of wounding to advanced / haemostatic resuscitation and provision of in-flight diagnostics. Continuation of in-flight resuscitation then allows physician-led decision making on critically unstable casualties. This allows either an expedited straight move from the HLS direct to the operating theatre or direct transfer to a regional neurosurgical centre. To prevent avoidable death,our unequivocal conclusion is that there must be an upper limit of 2 hours from wounding to surgical intervention (surgical haemorrhage control) for all casualties.

Outcome after vascular trauma in a deployed military trauma system

Background

Military injuries to named blood vessels are complex limb- and life-threatening wounds that pose significant difficulties in prehospital and surgical management. The aim of this study was to provide a comprehensive description of the epidemiology, treatment and outcome of vascular injury among service personnel deployed on operations in Afghanistan and Iraq.

Methods

Data from the British Joint Theatre Trauma Registry were combined with hospital records to review all cases of vascular trauma in deployed service personnel over a 5-year interval ending in January 2008.

Results

Of 1203 injured service personnel, 110 sustained injuries to named vessels; 66 of them died before any surgical intervention. All 25 patients who sustained an injury to a named vessel in the abdomen or thorax died; 24 did not survive to undergo surgery and one casualty in extremis underwent a thoracotomy, but died. Six of 17 patients with cervical vascular injuries survived to surgical intervention; two died after surgery. Of 76 patients with extremity vascular injuries, 37 survived to surgery with one postoperative death. Interventions on 38 limbs included 19 damage control procedures (15 primary amputations, 4 vessel ligations) and 19 definitive limb revascularization procedures (11 interposition vein grafts, 8 direct repairs), four of which failed necessitating three amputations.

Conclusion

In operable patients with extremity injury, amputation or ligation is often required for damage control and preservation of life. Favourable limb salvage rates are achievable in casualties able to withstand revascularization. Despite marked progress in contemporary battlefield trauma care, torso vascular injury is usually not amenable to surgical intervention.

Avoiding cavity surgery in penetrating torso trauma: the role of the computed tomography scan

INTRODUCTION

Surgical decision-making in torso trauma is complex. This paper looks at the role of the computed tomography (CT) scan in this decision-making process.

PATIENTS AND METHODS

Patients with significant torso trauma (high velocity gunshot wound [HVGSW], blast, stab) admitted to a military role 2 (enhanced) hospital facility during a 7-week period of Operation HERRICK 9 (Afghanistan, October to November 2008) are reported. The management of those patients undergoing a CT scan as part of the decision-making process at the time of admission is discussed.

RESULTS

Twenty eight patients with significant torso trauma were admitted to the facility during the study period; HVGSW (n = 15), blast (n = 9), stab (n = 4). Thirteen patients underwent a CT scan as part of the surgical decision-making process; HVGSW (n = 5), blast (n = 8). Imaging confirmed torso integrity in 12 patients, one of whom subsequently had a laparotomy for vascular control for on-table haemorrhage during lower limb surgery. One patient had a confirmed thoraco-abdominal injury, which was treated conservatively with tube thoracostomy and 'active observation'.

CONCLUSIONS

A CT scan formed part of the surgical decision-making process in about half of the patients admitted with significant torso trauma, and helped prevent unnecessary laparotomy in this forward military environment. Those patients with a blast injury were more likely to undergo CT scanning than those where the mechanism of injury was a HVGSW.

Penetrating missile injuries during the Iraqi insurgency

INTRODUCTION

Since the invasion of Iraq in 2003, the conflict has evolved from asymmetric warfare to a counter-insurgency operation. This study investigates the pattern of wounding and types of injuries seen in casualties of hostile action presenting to a British military field hospital during the present conflict.

PATIENTS AND METHODS

Data were prospectively collected on 100 consecutive patients either injured or killed from hostile action from January 2006 who presented to the sole coalition field hospital in southern Iraq.

RESULTS

Eighty-two casualties presented with penetrating missile injuries from hostile action. Three subsequently died of wounds (3.7%). Forty-six (56.1%) casualties had their initial surgery performed by British military surgeons. Twenty casualties (24.4%) sustained gunshot wounds, 62 (75.6%) suffered injuries from fragmentation weapons. These 82 casualties were injured in 55 incidents (mean, 1.49 casualties; range 1-6 casualties) and sustained a total 236 wounds (mean, 2.88 wounds) affecting a mean 2.4 body regions per patient. Improvised explosive devices were responsible for a mean 2.31 casualties (range, 1-4 casualties) per incident.

CONCLUSIONS

The current insurgency in Iraq illustrates the likely evolution of modern, low-intensity, urban conflict. Improvised explosive devices employed against both military and civilian targets have become a major cause of injury. With the current global threat from terrorist bombings, both military and civilian surgeons should be aware of the spectrum and emergent management of the injuries caused by these weapons.

Gastric adenocarcinoma metastatic to the skin: a report

Metastases to the skin from internal tumours are uncommon, yet they may be the first presentation of such malignancies. They usually arise from the breast, lung and large bowel. Skin metastases from gastric adenocarcinoma are extremely rare. We report a case of a patient with gastric adenocarcinoma who at presentation had multiple, clinically benign-looking skin nodules. Biopsy of these revealed metastatic deposits.