Air rifles--lethal weapons

Neurosurgical Care of Nonpowder Firearm Injuries: A Narrative Review of the Literature

Background

Nonpowder firearms discharge a projectile using compressed gases. Unlike traditional firearms, there is a perception that nonpowder guns do not cause serious injury. However, intracranial injury disproportionally affects children and can cause significant neurological disabilities and mortality. Management of nonpowder firearm injuries has received little attention in the literature and presents unique surgical challenges.

Materials and Methods

We conducted a narrative review of the literature of the management of nonpowder firearm injuries with particular emphasis on intracranial injury.

Results

Modern nonpowder firearms have muzzle velocities which are capable of penetrating the skin, eyes, and bone. Direct intracranial injury commonly results from entrance of projectile through thinner portions of the skull. Operative intervention is needed to debride and safely explore the trajectory to remove fragments which can easily cause neurovascular injury.

Conclusions

Neurosurgeons play a crucial role in managing serious nonpowder firearm injuries. A multidisciplinary team is needed to manage the direct results of penetrating injury and long-term sequalae.

Experimental effect of shots caused by projectiles fired from air guns with kinetic energy below 17 J

Pursuant to the Polish Weapons and Ammunitions Law (Legal Gazette No 53/1999 item 549 with subsequent amendments), air guns with kinetic energy of the fired projectiles below 17 J are not regarded as weapons. The aim of the study was to assess the potential effect of shots caused by projectiles of various mass and structure fired from air guns with kinetic energy below 17 J on human soft tissues. As a model of soft tissue, we used 20% gelatin blocks. After shooting, we measured the depth of gelatin block penetration by pellets fired from various distances and compared these results with autopsy findings. The results demonstrated that examined pneumatic guns may cause serious injuries, including damage to the pleura, pericardium, liver, spleen, kidneys, femoral artery, and thoracic and abdominal aorta. Experiment shown that gelatin blocks do not reflect fully the properties of the human body.

A contribution to the discussion on the safety of air weapons

Firearms legislation in the UK stems from the Firearms Act 1968 with its definition of a firearm as a lethal barrelled weapon of any description. The Act allows certain exceptions to be held without licence, most notably air weapons although these are limited by The Firearms (Dangerous Air Weapons) Rules 1969 and related regulations to below 12ft lb (16.3J) for air rifles and below 6ft lb (8.1J) for air pistols. Despite this there are occasional fatalities, typically 1 or 2 each year in the UK, from legally owned air weapons. In the USA there are over 20,000 visits each year to emergency departments due to injuries from air weapons and paintball guns. Despite this, limited research appears to have been carried out into the safety of air weapons and the present study tries to address this. Fresh samples of animal tissue were obtained from an abattoir or butcher and were embedded in ballistic gelatin. Pig heart, lung, liver and shoulder were used. By firing pellets into gelatin alone and into the combination of the gelatin and animal tissue it was possible to compare gelatin as a model for these tissues. The depth of penetration was similar but the residual track appeared to remain more open in the animal tissue. Pellets penetrated completely through the organ, with total penetration of gelatin and organ being typically around 10-15cm. Samples of pig, cow and chicken skin were placed in contact with the gelatin or embedded in the gelatin to simulate the effect of skin on penetration into a body. Chicken skin had no effect, pig skin stopped the pellet and cow skin was perforated by the pellet. If cow skin was embedded in the gelatin there was little effect on the total amount of penetration, but cow skin on the front surface of the gelatin reduced penetration by about 30%. Computed tomography was used to examine the pellet track and to calculate the volume of damage produced. However, due to the similar densities of gelatin and organ a technique had to be developed to differentiate phases. A barium salt paste was applied to outer surfaces and iodine solution or barium nitrate solution containing red food colouring was injected into the pellet track to enhance the contrast of the track. The track through the gelatin tended to enclose itself whereas the track through the organ remained more open, presumably due to the inhomogeneity of the fibrous nature of the tissue. Pellets were also fired at construction materials (wood, plasterboard and brick) and computed tomography used to determine the volume of damage created. Pellets perforated single layers of wood and plasterboard and would embed in a second layer. However, if the two layers were in contact the pellet did not penetrate the first layer. An air rifle pellet could therefore perforate house construction materials, although the resultant kinetic energy would be low and further damage would be limited. Some of the possible physical parameters are discussed that might help predict the degree of damage caused, but from this study it is not possible to define a limit which could be proposed as safe.

Pediatric ocular injuries from airsoft toy guns

PURPOSE

To report ocular injuries caused by airsoft guns in children.

METHODS

A retrospective chart review of pediatric patients who sustained ocular injuries related to airsoft guns between November 2005 and December 2007. Place of trauma, presenting symptoms and signs, surgical interventions performed, and final visual outcome were reviewed.

RESULTS

Thirty-two patients with a mean age of 8.8 ± 4.0 years (range: 1.5 to 18 years) were examined; 28 were boys (87.5%). Presenting visual acuity ranged from hand motions to 20/20 and could not be assessed in 2 patients. Hyphema was a common finding that was present in 24 cases, corneal abrasions were present in 10 cases, and raised intraocular pressure was present in 7 cases. Seven patients presented with traumatic cataract, and two had iridodialysis. Immediate surgical intervention was performed in 7 patients and 7 patients were scheduled for elective surgery. The patients presented after an average of 1.9 ± 1.9 days (range: 4 hours to 6 days) after the injury. Average follow-up was 18 days (range: 7 days to 5 months). Final visual acuity was 20/200 or worse in 5 patients, 20/40 or better in 23 patients, and could not be assessed in 2 cases.

CONCLUSION

Airsoft guns can cause a variety of serious injuries, sometimes necessitating operative intervention. The long-term morbidity from some of these injuries is significant. Airsoft guns are capable of inflicting serious and permanent ocular damage.

An investigation into the behaviour of air rifle pellets in ballistic gel and their interaction with bone

Although air weapons are considerably lower in power than other firearms, there is increasing concern that serious injuries can result from their misuse. The present study was therefore carried out to improve understanding of the terminal ballistic behaviour of air rifle pellets. Pellets were fired into ballistic gel under a variety of conditions. The pellets penetrated further than anticipated from their low cross-sectional density, and Bloom number was not necessarily a good guide to gel behaviour. Pellet penetration into the gel decreased with increasing gel concentration, and appeared to be linear at higher concentrations. Pointed pellets penetrated up to 50% further than rounded pellets. Power and range affect penetration, but other factors are also important, and power alone is not a simple guide to potential penetration. Test firings were also carried out firing pellets into ballistic gel that contained sections of animal bone. Computed tomography (CT) and visual observation were employed to record the interactions. CT scanning showed potential as a tool for examining pellet damage. The bone appeared to be undamaged, but the pellets were severely deformed on impact. If the pellet strikes the bone at an angle, less energy is absorbed by the impact and the pellet fragments may ricochet and cause further damage in the gel. A tentative model is proposed for estimating the energy absorbed by the impact.

Conventional radiographs: are they still the standard in localization of projectiles?

The penetration of air gun pellets in facial soft tissue can cause major problems during the removal of foreign bodies, although conventional radiography, computed tomography, image-guided surgical removal, and ultrasound have been applied to facilitate the procedure. It was the aim of the present case report to introduce a modified intraoperative method for the localization of air gun pellets, based on the use of radiopaque markers in conventional radiographs. A 66-year-old patient attempted to commit suicide by using an air gun. The pellet hit the right temporal region. A computed tomographic (CT) scan was acquired to localize the foreign body. The first attempt to remove the pellet through the penetrating wound failed. Because of a dislodgement of the pellet, the CT scan could no longer be used for the localization of the air gun pellet. As the air gun pellet was positioned under the zygomatic arch, ultrasound was unable to identify its position. Successful intraoperative localization of the projectile was performed after fixation of radiopaque markers to the skin in the region of the estimated localization, with conventional radiographs in 2 planes, acquired with a mobile dental x-ray device. Although the markers remained attached to the patient as reference makers, the air gun pellet was removed easily. The use of radiopaque markers in conventional radiographs in 2 planes allows fast, intraoperative localization of radiopaque foreign bodies within soft tissue. The procedure can be carried out with a conventional x-ray device that should be available in every oral and maxillofacial practice. The use of reference markers should be considered a standard procedure for the localization of radiopaque foreign bodies in the head and neck.

Perineal Sonography to Localize Airgun Pellet

A teenage boy presented to the emergency department with an accidental self-inflicted airgun injury to his perineum. Examination showed a small entry wound in the scrotal skin and the testes were normal. X-ray of the pelvis showed the pellet in the perineum without definite localization. Perineal sonography was performed preoperatively, which precisely localized the pellet in the perineal soft tissues for easy exploration and removal.

Air guns: toys or weapons?

Air guns and blank guns may appear relatively harmless at first glance, but they are, in fact, potentially destructive, even lethal, weapons. Approximately 2 to 2.5 million nonpowder firearms are sold annually, and again approximately 12.9 per 100,000 population are treated for such injuries in hospital emergency departments each year in the United States. Unfortunately, these guns are considered to be a toy for children. Therefore, incidents of air gun injuries are gradually increasing. Although such injuries may initially be considered trivial, it may signify severe internal tissue pathologies. These apparently trivial injuries may have catastrophic consequences if unnoticed. In this study, we report 4 cases with head injury due to a shot by these guns. The cases indicate that these people had used the guns belonging to their parents for the purpose of suicide. The cases also show that these machines are not innocent.

Injury risk of nonpowder guns

Nonpowder guns (ball-bearing [BB] guns, pellet guns, air rifles, paintball guns) continue to cause serious injuries to children and adolescents. The muzzle velocity of these guns can range from approximately 150 ft/second to 1200 ft/second (the muzzle velocities of traditional firearm pistols are 750 ft/second to 1450 ft/second). Both low- and high-velocity nonpowder guns are associated with serious injuries, and fatalities can result from high-velocity guns. A persisting problem is the lack of medical recognition of the severity of injuries that can result from these guns, including penetration of the eye, skin, internal organs, and bone. Nationally, in 2000, there were an estimated 21840 (coefficient of variation: 0.0821) injuries related to nonpowder guns, with approximately 4% resulting in hospitalization. Between 1990 and 2000, the US Consumer Product Safety Commission reported 39 nonpowder gun-related deaths, of which 32 were children younger than 15 years. The introduction of high-powered air rifles in the 1970s has been associated with approximately 4 deaths per year. The advent of war games and the use of paintball guns have resulted in a number of reports of injuries, especially to the eye. Injuries associated with nonpowder guns should receive prompt medical management similar to the management of firearm-related injuries, and nonpowder guns should never be characterized as toys.

Air-Gun Injuries: Initial Evaluation and Resultant Morbidity

Severity of injuries from air-powered weapons can be underappreciated. Transformation of these weapons into toys makes them available to children. Our experience reveals the underestimated injury severity and emphasizes need for prompt trauma evaluation. Retrospective chart review of children sustaining air-gun injuries and evaluated at a single, pediatric hospital from 1991 to 2002 was performed. Medical record numbers were retrieved from a trauma data base. Data included age, weapon type, firing distance, injury site, radiographic studies, operative intervention, length of stay, and long-term disability. Ocular injuries were excluded secondary to known severity. All other injuries and treatments are described. Thirty-four children, average age 10 years ± 3.3 years, sustained 35 injuries from 1991 through 2002. Twenty-one children required admission, 19 children required surgery, and 5 children experienced long-term disability. Average time to definitive care was 3 hours 12 minutes. Sites of injury included head, neck, chest, abdomen, and extremities. Average hospital stay was 4.3 days. In the pediatric population, air-gun injuries can be underestimated. Lack of collateral tissue damage makes wounds appear innocuous to unsuspecting medical personnel resulting in delayed care. During initial evaluation, injuries from air guns deserve the same respect as those caused by conventional firearms.

Ocular air-gun injury: 19 cases

There have been many calls for preventive action against injuries caused by air-guns. Eye injuries are particularly serious, and we conducted a retrospective study to review their characteristics. Ophthalmic consultants in the south-west region of England and South Wales were asked to recollect any injuries that had resulted from air weapons. Information was recorded on the nature and circumstances of the injury, subsequent management, and long-term effects. 19 cases of ocular injury were identified, sustained at mean age 19.7 years, all in the past decade. 15 of the victims were male. At least 12 shootings were accidental but 2 were deliberate. The injury was self-inflicted in 5 cases, and in 6 the assailant was known to the victim. 9 sustained ruptured globes and 8 had severe contusions. Ultimately 4 individuals required enucleation and 2 evisceration. At last review, visual acuity was no perception of light in 10 (53%) and "counting fingers" or worse in 16. Victims spent an average of nearly 10 days as an inpatient. The characteristics of the incidents that lead to ocular air-weapon injuries are unchanged. Reform of the firearms laws is probably the best way to prevention.

Life-threatening air rifle injuries to the heart in three boys

Air rifles, or BB guns, are generally thought of as childhood toys. Although most injuries are not serious, life-threatening events have been reported. Within a 1-year period, 3 boys presented after BB gun shots to the chest, all requiring surgical intervention for penetrating injuries to the heart. A 15-year-old underwent window pericardiotomy for hemopericardium with thrombus 24 hours after admission. Another, 5 years of age, underwent emergent exclusion of the cardiac apex for a traumatic ventricular septal defect. The third, 8 years old, had a right ventricular injury requiring an urgent subxiphoid pericardial window for tamponade. All recovered uneventfully. Increased public awareness, adult supervision, safety training, and appropriate legislation are needed to decrease the risks of these potentially lethal weapons.