Development of serial bio-shock tubes and their application.
OBJECTIVE: To design and produce serial shock tubes and further examine their application to experimental studies on blast injury. METHODS: Bio-medical engineering technique was used for the design and development of the serial shock tubes. One thousand four hundred and fifty nine animals (757 rats, 105 guinea pigs, 335 rabbits, 240 dogs and 22 sheep) were then used to test the wounding effects of the shock tubes. RESULTS: Three types of bio-shock tubes, that is, large-, medium- and small-scale shock tubes were made in our laboratory. The large-scale shock tube is 39 meters long; the inner diameter of the test section is 1 meter; and the maximum overpressure in the driving section is 10.3 MPa. A negative pressure could be formed by means of the reflected rarefactive wave produced by the end plate. The medium-scale shock tube is 34.5 meters long; the maximum overpressure in the driving section is 22 MPa; the test section is designed to be a knockdown, showing 5 basic types with inner diameter of 77 to 600 millimeters, which could be used for researches on overpressure, explosive decompression, underwater explosion, and so on. The small-scale shock tube is 0.5 meter long with the maximum endured overpressure of 68.6 MPa. Results from animal experiments showed that this set of shock tubes could induce various degrees of systemic or local blast injury in large or small animals. CONCLUSIONS: This set of bio-shock tubes can approximately simulate typical explosive wave produced by nuclear or charge explosion, and inflict various degrees of blast injury characterized by stability and reproducibility. Therefore, they can meet the needs of blast research on large and small animals. (+info
An unusual case of carbon monoxide poisoning.
Carbon monoxide, a gas originating from incomplete combustion of carbon-based fuels, is an important cause of human deaths. In this paper, we describe an unusual carbon monoxide poisoning in a dwelling without obvious sources of combustion gases, for which two adults had to be treated in a hyperbaric chamber. Carbon monoxide readings were taken in the house and in the neighboring homes. Methane gas and nitrogen oxide levels were also monitored in the house air. Soil samples were collected around the house and tested for hydrocarbon residues. The investigation revealed the presence of a pocket of carbon monoxide under the foundation of the house. The first readings revealed carbon monoxide levels of 500 ppm in the basement. The contamination lasted for a week. The investigation indicated that the probable source of contamination was the use of explosives at a nearby rain sewer construction site. The use of explosives in a residential area can constitute a major source of carbon monoxide for the neighboring populations. This must be investigated, and public health authorities, primary-care physicians, governmental authorities, and users and manufacturers of explosives must be made aware of this problem. (+info
Measuring the noise attenuation of shotblasting helmets.
Air-fed blasting helmets are used in abrasive blasting operations to provide essential face, eye and respiratory protection. BS EN 271: 1995 (equivalent to the European Standard EN 271: 1997), the standard that deals with the construction of blasting helmets, addresses the above matters and also the problem of noise generated by the breathing air supply. However it has no requirements for manufacturers to measure or report the helmet's ability to attenuate the very high levels of noise generated by the blasting process. The aim of the project was to develop a test method to measure the noise attenuation of shotblasting helmets. The method developed is an objective measurement, using a head and torso simulator (HATS), which provides a suitable means for helmet manufacturers to report their product's ability to attenuate blasting noise. The results from this project showed that the HATS currently prescribed by BS EN 271: 1995 can be used for measuring the noise attenuation of helmets against typical shotblasting noise. Using such a HATS in the proposed test method will give attenuation values that correlate well with those measured using human subjects. Therefore the HATS already used by manufacturers to show compliance of their product with BS EN 271: 1995 could also be used to provide information on the helmet's noise attenuation. Results from this project also showed that the same HATS can be used, in place of human subjects, to measure the air supply noise according to the method defined in BS EN 271: 1995. BS EN 271: 1995 is due for revision in 2000. The results from this work should be used to influence future revisions of the standard so that requirements to measure and report noise attenuation of shotblasting helmets are considered, a major omission in the present standard. (+info
Injuries from fireworks in the United States.
Fireworks traditionally are used in the United States to celebrate Independence Day on July 4th. The U.S. Consumer Product Safety Commission (CPSC) estimates that 8500 persons in the United States are treated in emergency departments each year for fireworks-related injuries (1). Of all fireworks-related injuries, 70%-75% occur during a 30-day period that surrounds the July 4th holiday (June 23-July 23) (2). Seven of every 100 persons injured by fireworks are hospitalized, approximately 40% of those injured are children aged < or = 14 years, and males are injured three times more often than females (1). The injury rate is highest among boys aged 10-14 years (3). Most commonly, injuries from fireworks affect the hands (34%), face (12%), and eyes (17%) (4). Injuries are more frequent and more severe among persons who are active participants than among bystanders (3). (+info
Effect of epidermal growth factor and dexamethasone on explosive deafness.
OBJECTIVE: To study the expression of epidermal growth factor receptor (EGFR) on cochlear hair cells of normal and explosion-stricken guinea pigs and the effects of epidermal growth factor (EGF) and dexamethasone (DXM) treatment for blast hearing loss. METHODS: Immunohistochemical technique and auditory brainstem response (ABR) test were used. RESULTS: Scattered expression of EGFR was seen in inner hair cells (IHCs) and outer hair cells (OHCs) in normal guinea pigs. Segmentally distributing positive reaction was also located in stereocilia of hair cells. Distribution of EGFR reaction was seen in the cytoplasm of IHC 24 hours after exposure to blasts, and in the stereocilia of IHC and the cuticular plate of OHC 72 hours postexposure. At one week EGFR reaction in hair cells increased obviously and part of OHC stereocilia also showed positive reaction. EGFR reaction reduced at two weeks, though positive reaction could still be found in the stereocilia of hair cells at one month. Combination of EGF and DXM administrations promoted hearing recovery significantly. CONCLUSIONS: The healing of injured hair cells may be related to EGF. (+info
The Tower of London bomb explosion.
After the detonation of a bomb in the Tower of London 37 people were brought to St. Bartholomew's Hospital. The explosion caused numerous severe injuries of a type rarely seen in peacetime. (+info
Report on injuries sustained by patients treated at the Birmingham General Hospital following the recent bomb explosions.
As a result of recent bomb explosions a total of 82 patients were treated at the Birmingham General Hospital, 61 with minor injuries. Bomb injuries may be divided into three main groups due to the blast effect (such as blast lung and ruptured tympanic membranes), the flash (such as burns to the exposed part of the body), and shrapnel (which may cause a wide variety of injuries). The amount of warning of such explosions is usually minimal, and so the prepared accident schemes of most hospitals are inappropriate. If the disaster occurs outside normal working hours much responsibility initially falls on the resident staff. This report gives some idea of the type of injuries they are likely to see. (+info
The World Trade Center attack. Lessons for all aspects of health care.
The attack on the World Trade Center had the potential to overwhelm New York's health services. Sadly, however, the predicted thousands of treatable patients failed to materialize. Horror and sadness has now been replaced by anger, fear, and the determination to be better prepared next time. This determination not only exists in politics but also in health care, and as with all attempts to enforce change there needs to be a period of collecting opinions and data. This article introduces nine reviews in Critical Care offering varied health care perspectives of the events of 11 September 2001 from people who were there and from experts in disaster management. (+info