Refining mass casualty plans with simulation-based iterative learning.

BACKGROUND: Preparatory, written plans for mass casualty incidents are designed to help hospitals deliver an effective response. However, addressing the frequently observed mismatch between planning and delivery of effective responses to mass casualty incidents is a key challenge. We aimed to use simulation-based iterative learning to bridge this gap. METHODS: We used Normalisation Process Theory as the framework for iterative learning from mass casualty incident simulations. Five small-scale 'focused response' simulations generated learning points that were fed into two large-scale whole-hospital response simulations. Debrief notes were used to improve the written plans iteratively. Anonymised individual online staff surveys tracked learning. The primary outcome was system safety and latent errors identified from group debriefs. The secondary outcomes were the proportion of completed surveys, confirmation of reporting location, and respective roles for mass casualty incidents. RESULTS: Seven simulation exercises involving more than 700 staff and multidisciplinary responses were completed with debriefs. Usual emergency care was not affected by simulations. Each simulation identified latent errors and system safety issues, including overly complex processes, utilisation of space, and the need for clarifying roles. After the second whole hospital simulation, participants were more likely to return completed surveys (odds ratio=2.7; 95% confidence interval [CI], 1.7-4.3). Repeated exercises resulted in respondents being more likely to know where to report (odds ratio=4.3; 95% CI, 2.5-7.3) and their respective roles (odds ratio=3.7; 95% CI, 2.2-6.1) after a simulated mass casualty incident was declared. CONCLUSION: Simulation exercises are a useful tool to improve mass casualty incident plans iteratively and continuously through hospital-wide engagement of staff.

Primary amputation versus limb salvage in upper limb major trauma: a systematic review.

PURPOSE: Severe upper limb injuries can result in devastating consequences to functional and psychological well-being. Primary objectives of this review were to evaluate indications for amputation versus limb salvage in upper limb major trauma and whether any existing scoring systems can aid in decision-making. Secondary objectives were to assess the functional and psychological outcomes from amputation versus limb salvage. METHODS: A systematic review was carried out in accordance with PRISMA guidelines. A search strategy was conducted on the MEDLINE, EMBASE, and Cochrane databases. Quality was assessed using the ROBINS-I tool. The review protocol was registered in PROSPERO. RESULTS: A total of 15 studies met inclusion criteria, encompassing 6113 patients. 141 underwent primary amputation and 5972 limb salvage. General indications for amputation included at least two of the following: uncontrollable haemodynamic instability; extensive and concurrent soft tissue, bone, vascular and/or nerve injuries; prolonged limb ischaemia; and blunt arterial trauma or crush injury. The Mangled Extremity Severity Score alone does not accurately predict need for amputation, however, the Mangled Extremity Syndrome Index may be a more precise tool. Comparable patient-reported functional and psychological outcomes are seen between the two treatment modalities. CONCLUSIONS: Decision regarding amputation versus limb salvage of the upper limb is multifactorial. Current scoring systems are predominantly based on lower limb trauma, with lack of robust evidence to guide management of the upper extremity. Further high-quality studies are required to validate scoring systems which may aid in decision-making and provide further information on the outcomes from the two treatment options.

Finger abduction as a novel function of the extensor digitorum brevis manus muscle.

A 25-year-old female presented with a chronic scapho-lunate ligament injury with development of carpal instability requiring reconstruction. During a standard dorsal longitudinal mid-line approach to the carpus, an extensor digitorum brevis manus (EDBM) muscle was found taking its origin from the dorsal wrist capsule overlying the lunate with innervation from the posterior interosseous nerve (PIN). Electrical stimulation of the muscle belly demonstrated abduction of the middle finger. The EDBM is a rare anatomical variant of the extensor compartment of the wrist and may be encountered during surgical approaches. Where possible these variant muscles should be carefully dissected off underlying structures, preserved and repaired at the conclusion of a procedure to ensure no perceived functional deficit to the patient. We present a case of a previously undescribed EDBM muscle function of pure finger abduction with no extension and a surgical technique of preserving its origin. We propose that the middle finger variant of the EDBM should be re-named the extensor digitorum brevis medius to reflect our findings.

The contribution of the posterolateral capsule to elbow joint stability: a cadaveric biomechanical investigation.

BACKGROUND: Elbow posterolateral rotatory instability occurs after an injury to the lateral collateral ligament complex (LCLC) in isolation or in association with an osteochondral fracture of the posterolateral margin of the capitellum (Osborne-Cotterill lesion [OCL]). The contribution to elbow stability of the posterolateral capsule, attached to this lesion, is unknown. This study quantified the displacement of the radial head on simulated posterior draw with sectioning of the posterior capsule (a simulated OCL) or LCLC. METHODS: Biomechanical testing of the elbow was performed in 8 upper limb cadavers. With the elbow 0°, 30°, 60°, and 90° degrees of flexion, posterior displacement of the radius was measured at increments of a load of 5 N up to 50 N. A simulated OCL and LCLC injury was then performed. RESULTS: A simulated OCL results in significantly more displacement of the radial head compared with the intact elbow at 30° to 60° of elbow flexion. LCLC resection confers significantly more displacement. An OCL after LCLC resection does not create further displacement. CONCLUSIONS: The degree of radial head displacement is greater after a simulated OCL at 30° to 60° of flexion compared with the intact elbow with the same load but not as great as seen with sectioning of the LCLC. This study suggests that the posterior capsule attaching to the back of the capitellum is important to elbow stability and should be identified as the Osborne-Cotterill ligament. Clinical studies are required to determine the importance of these biomechanical findings.

Prophylaxis for blood-borne diseases during the London 7/7 mass casualty terrorist bombing: a review and the role of bioethics.

The suicide bombings in London on 7 July 2005 resulted in a mass casualty situation. Over 50% of casualties were treated at the Royal London Hospital where clinicians witnessed large numbers of severely injured patients. In some casualties human biological foreign material was found embedded in the soft tissue originating from the suicide bombers or other casualties. This had the potential of placing individuals at risk of transmission of blood-borne diseases. Advances in the fields of medicine and biology have led to increased survivorship in the context of trauma and mass casualty incidents. This has resulted in the emergence of ethical scenarios surrounding patient management. A systematic review of the literature of the 7/7 bombings, and suicide bombings reported globally, where biological implantation is noted, was performed to examine the medicolegal issues arising during such attack. Twelve casualties with human tissue implanted were recorded in the 7/7 bombings. While all patients at risk were given prophylaxis based on recommendations by the Health Protection Agency, several ethical considerations surfaced as a result. In this paper, we compare the sequence of events and the management process of the victims of the 7/7 bombings and the evidence-based research regarding blood-borne infection transmission. Furthermore, it explores the ethical dilemmas, experienced by the senior author on 7/7, surrounding prophylaxis for blood-borne diseases and protocols to avoid confusion over best practice in future bombing incidents.

"Doomed to go in company with miserable pain": surgical recognition and treatment of amputation-related pain on the Western Front during World War 1.

The principal feature of injuries from World War 1 was musculoskeletal trauma and injury to peripheral nerves as a result of damage to the upper and lower limbs caused by gunshot wounds and fragments of artillery munitions. Amputation was used as a treatment in field hospitals to save lives; limb conservation was a secondary consideration. A century later, the principal feature of injuries to soldiers in today's wars in Iraq and Afghanistan is also musculoskeletal trauma and injury to the peripheral nerves caused by improvised explosive devices. Common to both types of injury is postamputation pain. We searched The Lancet's archives in this Series paper to show the efforts of surgeons in World War 1 to understand and treat postamputation pain in its own right both during and immediately after the war. Despite unprecedented patient numbers and levels of civilian medical expertise, little progress was made in providing relief from this type of pain, a grave concern to the surgeons treating these soldiers. Today postamputation pain is understood beyond a surgical context but remains a complex and poorly understood condition with few effective treatments.

Heterotopic ossification: a systematic review.

Heterotopic ossification (HO) is the formation of mature lamellar bone in extraskeletal soft tissues. It was first described 1000 years ago in the healing of fractures, and in relation to military wounds, texts from the American Civil War and World War I refer to HO specifically. It continues to cause problems to injured service personnel; the consequences of wound and soft tissue complications in traumatic amputations pose particular problems to rehabilitation and prosthetic use. While HO is seen in rare genetic conditions, it is most prevalent after joint replacement surgery and trauma. In the civilian setting HO has been commonly described in patients after traumatic brain injuries, spinal cord injuries and burns. Militarily, as a consequence of recent operations, and the characteristic injury of blast-related amputations, a renewed interest in HO has emerged due to an increased incidence seen in casualties. The heterogeneous nature of a blast related amputation makes it difficult for a single aetiological event to be identified, although it is now accepted that blast, amputation through the zone of injury, increased injury severity and associated brain injuries are significant risk factors in HO formation. The exact cellular event leading to HO has yet to be identified, and as a consequence its prevention is restricted to the use of anti-inflammatory medication and radiation, which is often contraindicated in the acute complex military casualty. A systematic review in PubMed and the Cochrane Database identified research articles related to HO to illustrate the military problem of HO and its management, current research concepts and experimental theories regarding HO. This also served as a gap analysis providing the researchers detail of any knowledge deficit in this field, in particular to the military aspects of HO; 637 out of 7891 articles initially identified that referenced HO were relevant to this review.

Wide-Awake Wrist and Small Joints Arthroscopy of the Hand.

The minimally invasive nature of wrist and small joint arthroscopy renders it particularly suitable for the application of the wide-awake local anesthesia no tourniquet (WALANT) technique. The application of WALANT wrist and small joint arthroscopy has given surgeons the ability to visualize both static and dynamic movements of a joint, to show the pathology and discuss with the patient, and to visualize a patient's repaired structures. This reinforces confidence in surgeons and encourages patients to comply with postoperative rehabilitation.

Injury risk of interphalangeal and metacarpophalangeal joints under impact loading.

Injuries to the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints of the hand are particularly disabling. However, current standards for hand protection from blunt impact are not based on quantitative measures of the likelihood of damage to the tissues. The aim of this study was to evaluate the probability of injury of the MCP and PIP joints of the human hand due to blunt impact. Impact testing was conducted on 21 fresh-frozen cadaveric hands. Unconstrained motion at every joint was allowed. All hands were imaged with computed tomography and dissected post-impact to quantify injury. An injury-risk curve was developed for each joint using a Weibull distribution with dorsal impact force as the predictive variable. The injury risks for PIP joints were similar, as were those for MCP joints. The risk of injury of the MCP joints from a given applied force was significantly greater than that of the PIP joints (p = 0.0006). The axial forces with a 50% injury risk for the MCP and PIP joints were 3.0 and 4.2 kN, respectively. This is the first study to have investigated the injury tolerance of the MCP and PIP joints. The proposed injury curves can be used for assessing the likelihood of tissue damage, for designing targeted protective solutions such as gloves, and for developing more biofidelic standards for assessing these solutions.

Importance of Consistent Datasets in Musculoskeletal Modelling: A Study of the Hand and Wrist.

Hand musculoskeletal models provide a valuable insight into the loads withstood by the upper limb; however, their development remains challenging because there are few datasets describing both the musculoskeletal geometry and muscle morphology from the elbow to the finger tips. Clinical imaging, optical motion capture and microscopy were used to create a dataset from a single specimen. Subsequently, a musculoskeletal model of the wrist was developed based on these data to estimate muscle tensions and to demonstrate the potential of the provided parameters. Tendon excursions and moment arms predicted by this model were in agreement with previously reported experimental data. When simulating a flexion-extension motion, muscle forces reached 90 N among extensors and a co-contraction of flexors, amounting to 62.6 N, was estimated by the model. Two alternative musculoskeletal models were also created based on anatomical data available in the literature to illustrate the effect of combining incomplete datasets. Compared to the initial model, the intensities and load sharing of the muscles estimated by the two alternative models differed by up to 180% for a single muscle. This confirms the importance of using a single source of anatomical data when developing such models.

Surgical Management of Musculoskeletal Trauma.

Musculoskeletal injuries cause a significant burden to society and can have a considerable impact on patient morbidity and mortality. It was initially thought that these patients were too sick to undergo surgery and later believed that they were too sick not to undergo surgery. The pendulum has subsequently swung back and forth between damage control orthopedics and early total care for polytrauma patients with extremity injuries and has settled on providing early appropriate care (EAC). The decision-making process in providing EAC is reviewed in an effort to optimize patient outcomes following severe extremity trauma.

Heterotopic Ossification: A Review of Current Understanding, Treatment, and Future.

Heterotopic ossification is the formation of bone at extraskeletal sites. The incidence of heterotopic ossification in military amputees from recent operations in Iraq and Afghanistan has been demonstrated to be as high as 65%. Heterotopic ossification poses problems to wound healing, rehabilitation, and prosthetic fitting. This article details the current evidence regarding its etiology, prevention, management, and research strategies.