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Investigation of incidents of terrorism involving commercial aircraft.

Deaths resulting from terrorism involving aircraft have occurred incident to hijackings as well as bombings. Passengers or groups of passengers have been chosen by terrorists as the recipients of violence based on citizenship, religion, and political beliefs. They have usually been segregated from other passengers and subsequently mistreated and/or murdered. Thorough documentation of the injuries of victims is essential to the investigation of such atrocities; a medicolegal autopsy correlated with a scene investigation is of paramount importance. Aircraft bombings can create extremely sensitive political situations and public demands for quick resolution. The autopsy of victims in such circumstances, if properly conducted, can yield invaluable trace evidence leading to the identification of the explosive device. The examination of any surviving victims as well as the aircraft is also critical in reconstructing the event. Deaths occurring as the result of in-flight aircraft bombings can produce injuries by five different mechanisms, viz. blast, shrapnel, decompression, impact with the aircraft, and ground impact.

Aircraft↗

Oral and maxillofacial aspects of diving medicine.

Sport diving has witnessed explosive growth in the past decade, as 8.5 million people are certified in the United States alone. Even though scuba diving is a relatively safe sport, there are serious risks that all divers must consider. Beyond the better-known sequelae such as decompression sickness, middle ear dysfunction, and potential central nervous system effects, scuba diving also carries inherent risk to the maxillofacial region. Atypical facial pain, temporomandibular joint dysfunction, sinus barotraumas, and barodontalgia have all been reported by dentists and physicians treating military, commercial, and sport divers. Additionally, clinicians must address anatomic concerns for would-be divers, including cleft lip and palate, edentulism, or patients with pre-existing temporomandibular dysfunction, midfacial trauma, or craniomaxillofacial surgery. Health care professionals should have a thorough understanding of the implications of scuba diving for consultation and recommendation regarding diving fitness and the treatment of adverse effects of scuba diving to the maxillofacial region.

Barotrauma↗

Simulation of the dynamics of decompression sickness bubbles and the generation of new bubbles.

This communication introduces a system of equations for simulating the dynamics of growth and decay of decompression bubbles. The equations are solved by a numerical method and account for gas diffusion, the action of surface tension, tissue N2 washout by blood, and the rate of ascent from depth. The simulations demonstrate how inward diffusion of N2 can generate a persistent gas bubble from a nucleation process or a nucleus (these are provisionally defined as entities that can give rise to a small bubble of a certain size); an explosive positive-feedback loop is set off as the enlarging radius decreases the pressure due to surface tension. Generation of persistent bubbles is most likely during ascent from depth when PN2 inside any gas phase is decreasing rapidly and PN2 outside is still high before appreciable tissue washout has occurred. The "susceptibility" for the generation of a persistent bubble at any time can be defined as the reciprocal of the difference, at that time, between partial pressure of the nitrogen in tissue and in a spherical bubble of the size that is characteristic of the nucleation process or nucleus; susceptibility is less when ascent is slow because PN2 in bubbles stays high while washout removes N2 from the tissue.

Atmospheric Pressure↗

Raman scattering studies of the high-pressure stability of pentaerythritol tetranitrate, C(CH2ONO2)4.

High-pressure Raman scattering studies have been performed on a crystalline energetic material, pentaerythritol tetranitrate C(CH2ONO2)4 (PETN), an important secondary explosive. In situ, ambient-temperature investigations employed diamond anvil cell techniques and nitrogen as a quasi-hydrostatic-pressure-transmitting medium. The pressure-induced alterations in the profiles of the Raman lines, including positions, bandwidths, and intensities, were studied in a compression sequence up to about 31.3 GPa and in a subsequent decompression to ambient conditions. The observed changes of the Raman spectra implied that PETN gradually densified and compressed smoothly up to the highest investigated pressures. Compression below 12 GPa gradually shifted all Raman peaks to higher frequencies without significantly changing their relative intensities or bandwidths. At higher pressures, the peak intensities of the Raman spectra decreased considerably and the bands broadened significantly. The Raman spectrum of the material quenched from 31.3 GPa to ambient conditions indicated that no pressure-driven permanent reconstructive modification or decomposition of the PETN structure occurred. That is, the spectral changes were completely reversible upon compression and subsequent decompression to ambient conditions.

Journal Article↗

Tire explosion injuries.

Twenty-five patients hospitalized with injuries sustained from tire explosions from 1980 to 1987 were reviewed. Injuries occurred directly from the tire rim or parts of its assembly, from the patient being thrown against adjacent unyielding structures, or a combination of these. Lethal or life-threatening injuries do occur, so these patients initially must be triaged as polytrauma patients. Resuscitation and expeditious attention to life-threatening injuries must be provided when necessary. Serious head, facial, eye, and upper extremity injuries occurred frequently. Pelvic and long-bone fractures, particularly those of the femur, are stabilized primarily as part of the overall treatment of the polytraumatized patient. Open fractures and fractures with arterial injuries and/or compartment syndromes are primarily decompressed, debrided, and appropriately stabilized. After life-threatening and limb-threatening injuries are attended, eye injuries that threaten sight should be addressed. While hand, wrist, and other upper extremity injuries that do not fall in the above categories may not require immediate or primary treatment, they are often critical in determining the patient's final outcome. This is particularly true since most patients are manual workers, often mechanics. Therefore, hand, wrist, and upper extremity injuries should be treated as early as possible and in parallel with other injuries to achieve optimal results and minimize impairment, disability, and time and economic loss from work. Strong emphasis should be placed on education and safety training in preventing this severe form of civilian trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Occupational↗

A burn mass casualty event due to boiler room explosion on a cruise ship: preparedness and outcomes.

The purpose of this study was to review our experience with a mass casualty incident resulting from a boiler room steam explosion aboard a cruise ship. Experience with major, moderate, and minor burns, steam inhalation, mass casualty response systems, and psychological sequelae will be discussed. Fifteen cruise ship employees were brought to the burn center after a boiler room explosion on a cruise ship. Eleven were triaged to the trauma resuscitation area and four to the surgical emergency room. Seven patients were intubated for respiratory distress or airway protection. Six patients had >80 per cent burns with steam inhalation, and all of these died. One of the 6 patients had 99 per cent burns with steam inhalation and died after withdrawal of support within the first several hours. All patients with major burns required escharotomy on arrival to trauma resuscitation. One patient died in the operating room, despite decompression by laparotomy for abdominal compartment syndrome and pericardiotomy via thoracotomy for cardiac tamponade. Four patients required crystalloid, 20,000 mls/m2-27,000 ml/m2 body surface area (BSA) in the first 48 hours to maintain blood pressure and urine output. Three of these four patients subsequently developed abdominal compartment syndrome and died in the first few days. The fourth patient of this group died after 26 days due to sepsis. Five patients had 13-20 per cent bums and four patients had less than 10 per cent burns. Two of the patients with 20 per cent burns developed edema of the vocal cords with mild hoarseness. They improved and recovered without intubation. The facility was prepared for the mass casualty event; having just completed a mass casualty drill several days earlier. Twenty-six beds were made available in 50 minutes for anticipated casualties. Fifteen physicians reported immediately to the trauma resuscitation area to assist in initial stabilization. The event occurred at shift change; thus, adequate support personnel were instantaneously to hand. Our mass casualty preparation proved useful in managing this event. Most of the patients who survived showed signs of post-traumatic stress syndrome, which was diagnosed and treated by the burn center psychology team. Despite our efforts at treating large burns (>80%) with steam inhalation, mortality was 100 per cent. Fluid requirements far exceeded those predicted by the Parkland (Baxter) formula. Abdominal compartment syndrome proved to be a significant complication of this fluid resuscitation. A coordinated effort by the facility and preparation for mass casualty events are needed to respond to such events.

Body Surface Area↗

[Therapy of middle ear injuries caused by explosive devices].

Forty nine wounded with the explosive injury of the middle ear were treated. The largest number of injuries were ruptures of the ear drum (79.35%), followed by the break of the ossicular chain (15.87%) and the fractures of the mastoid, along with the paralysis of the facial nerve (4.77%). In therapeutic procedure the reposition and connection of the eardrum parts and 'patch' technique were performed, and in case of perforation persistence longer than four months myringoplasty was done. Injuries of the auditory bones were solved by ossiculoplasty, and injuries of facial nerve by decompression and neuro suture. In 66% spontaneous healing of rupture occurred and the ossicular chain was successfully fixed in 80% of injuries while the reparation of the facial nerve was partially achieved. The acute secondary infection developed in 18% and the chronic otitis in 10% of cases. The early reposition of the eardrum rupture is recommended due to infection prevention of the middle ear and in order to stimulate the spontaneous improvement, while the surgical treatment is recommended in cases with persistent rupture or conductive loss of hearing lasting longer than four months.

Adolescent↗

Recovery of pelvic limb function in dogs following acute intervertebral disc herniations.

Chondrodystrophoid breeds of dog are prone to explosive herniation of mineralized disc material into the thoracolumbar spinal canal. The resulting acute spinal cord injury may represent an excellent spontaneous model of acute traumatic spinal cord injury. The aims of this study were to quantify the recovery of dogs following acute disc herniations, to evaluate external factors that influence recovery, and to identify a group of dogs suitable for use in clinical trials on neuroprotective drugs. The gait of 88 dogs with thoracolumbar disc herniations was scored at the time of injury and 2, 4, and 12 weeks after surgical decompression. Dogs were placed into four groups dependent on the severity of presenting signs; dogs in group 1 had the most severe injury severity. Group 1 dogs showed a variable but incomplete recovery by 12 weeks. Dogs in groups 2 and 3 recovered uniformly but more completely, while dogs in group 4 made a rapid and excellent recovery and were deemed unsuitable for clinical trials. Combining dogs in groups 1, 2 and 3 produced a population of dogs with incomplete recovery by 12 weeks. Power analysis revealed that 87 such dogs would be needed per treatment group to detect a 20% change in function with a power of 95%. The number needed reduced drastically to 19 by eliminating dogs in group 1, but this produced less room for functional improvement. External factors did not appear to influence outcome. We conclude that dogs with spontaneous disc herniations provide a useful model of acute spinal cord injury for clinical trials.

Animals↗

The first histological demonstration of pancreatic oxidative stress in human acute pancreatitis.

Necrotizing acute pancreatitis is associated with an inflammatory explosion involving numerous pro-inflammatory mediator cascades and oxidative stress. Acinar oxygen free radical production aggravates pancreatic tissue damage, and promotes cellular adhesion molecule upregulation resulting in leukocyte adherence and activation. The cerium capture oxygen free radical histochemistry combined with reflectance confocal laser scanning microscopy allows the "in situ" histological demonstration of oxygen free radical formation in live tissues. Here we present a case report, where oxidative stress is demonstrated on a histological level for the first time in human acute pancreatitis. A 44-year-old male patient suffering from acute exacerbation of his chronic pancreatitis developed a pancreato-pleural fistula with amylase-rich left pleural exudate causing respiratory compromise. Subsequent to an urgent thoracic decompression a distal pancreatectomy and splenectomy was performed with the closure of abdomino-thoracic fistula. The postoperative course was uneventful, except for a transient pancreatico-cutaneous fistula, which healed after conservative treatment. To carry out cerium capture oxygen free radical histochemistry the resected pancreas specimen was readily perfused with cerium-chloride solution through the arteries on the resection surface. Frozen sections were cut, E-, P-selectin, ICAM and VCAM were labeled by immunofluorescence. The tumor-free margin of an identically treated pancreas carcinoma specimen served as a control. Intrapancreatic oxidative stress and cellular adhesion molecule expression were detected by confocal laser scanning microscopy. Numerous pancreatic acini and neighboring capillaries showed oxygen free radical-derived cerium-perhy-droxide depositions corresponding to strong local oxidative stress. Acinar cytoplasmic reflectance signals suggested xanthine-oxidase as a source of oxygen free radicals. These areas presented considerably increased endothelial P-selectin expression with adherent, oxygen free radical-producing polymorphonuclear leukocytes displaying pericellular cerium-reflectance. Modest ICAM upregulation was noted, E-selectin and VCAM expression was negligible. The control pancreas specimen showed minimal oxidative stress with weak, focal P-selectin expression. The development of deleterious pancreatic oxidative stress was based on indirect evidence in human acute pancreatitis. To the best of our knowledge this is the first report demonstrating persistent intrapancreatic oxidative stress histologically in human acute pancreatitis. We have noted P-selectin overexpression with a preponderance in the areas of acinar oxidative stress.

Adult↗