Intraocular penetration of toxic substances

PURPOSE: The seriousness of ocular alkali burns has been linked to the rapidity with which the alkali enters the eye. The authors report the results of an experimental study on intraocular ammonia penetration. MATERIALS AND METHODS: 23 eyes of New Zealand albino rabbits were burned by applying for one minute 100 ul of a solution titrating 15.3 percent of ammonia. A pH meter probe was inserted into the anterior chamber beforehand to permit pH measurements every 5 seconds. Experiments were carried out after 1,3,5,10 and 30 minutes. The ammonia concentration was measured at the end of the experiment by puncturing the anterior chamber. RESULTS: The pH increased 1 to 3 minutes after applying ammonia on the cornea, reaching a maximum (mean) of 10 five to six minutes later, before an exponential decrease. After 30 minutes, the pH was always more than the physiological pH. The penetration ratio of ammonia through the cornea is about 11 percent. At 30 minutes, the concentration of ammonia is low. The pH observed differs from the calculated pH. DISCUSSION: The difference between observed and calculated pH indicates increases with an intervening plateau, showing the existence of two successive acid-base chemical reactions between ammonia and two types of acid. In addition, the amount of protein destroyed by ammonia can be calculated. CONCLUSIONS: These data show for the time the possibility of calculating the density of proteins destroyed in vivo by a base penetrating the anterior chamber. This opens the possibilty of interesting research work, because it is possible to relate the density of proteins destroyed in the eye to the pK of this base, and to forecast the potential danger of a base of biological tissues.(AU)

Ocular ammonia burns: treatment

PURPOSE: The authors present the results of an experimental study to support the proposal for a delay in ocular bathing in the treatment of severe ocular burns due to ammonia. This study compares two solution of ocular wash: physiological serum and Diphoterine. MATERIALS AND METHODS: 23 eyes of New Zealand albino rabbits were burned for one minute by 100 ul of a solution containing 15.3 percent ammonia. Then, each eye was washed by an ocular wash of 250 ml of physiological serum, or of 250 ml of Diphoterine, after a delay of 1,3,5,10 and 30 minutes. The effects were appraised by measuring the anterior chamber, the concentration of ammonia in the anterior chamber, and by the cytopathological analysis of these burned corneas. RESULTS: An ocular wash with Diphoterine in the first few minutes following an ocular burn induces an inflexion of the pH graph, contrary to an ocular wash with physiological serum. On the other hand, there is no inflexion of the pH graph at 30 minutes, and the concentration of ammonia in the anterior chamber is low at that time. The cytopathological analysis shows stromal oedema with the ocular wash by physiological serum, but not when Diphoterine ocular wash is used. DISCUSSION AND CONCLUSIONS: This study proves the importance of ocular bathing in the first minutes following an ocular burn by ammonia. The efficacy of an external ocular wash by Diphoterine features; the importanve of sequelae has been linked to the initial stromal oedema.(AU)

Chemical burns as assault injuries in Jamaica

A three-fold greater incidence of chemical burn injuries in Jamaican hospitals, compared to burn centers in other industrial countries, underscores the problem of the use of common chemicals for assault weapons in this country. With the increased availability of guns for personal use, many Jamaicans learned the value of carrying household chemicals such as sulphuric acid from batteries or sodium hydroxide obtained from cleaning supplies. Chemical carried in a container, such as one might carry mace, afforded a means of defence among the lower socioeconomic groups who could not afford handguns. The use of dangerous chemicals for defensive weapons has extended to the use of chemicals for assault. The pattern of chemical injury differs significantly from most reports in the literature in both prevalence and aetiology. This review was prepared to examine these injuries with a view to planning strategies for prevention. (AU)

Caustic ingestion in Jamaica: 1982-1992 - abstract

A study on caustic ingestion in Jamaica was done by reviewing all the cases treated at Bustamante Hospital for Children, Kingston Public Hospital, University Hospital and National Chest Hospital between 1982 and 1992. The objectives of the study were: (1) To find the age groups most affected. (2) To assess the effectiveness of our treatment methods (3) To understand the complications of caustic ingestion and plan preventive approaches. All the hospital records, including clinical, surgical, and radiological procedures were carefully assessed and verified. The age groups most frequently affected were 0-5 and 5-10 years and the most serious complications were oesophageal and laryngeal burns. We concluded that superficial burns were manageable with antibiotics, steroids and nasogastric feeds but deep burns ended up with surgical augmentation or replacement of organs (AU)

Chemical burns in Jamaica - an urban social problem - abstract

A ten-year survey of admissions for acute burn injury was undertaken in eight hospitals in Jamaica for the period January 1981 to December 1990. Of 4,234 burn admissions, 562 or 13 percent were due to chemical injury and almost half of these resulted from interpersonal violence. More than 80 percent of these patients were admitted to four hospitals situated in urban regions of high population density (AU)

Caustic strictures of the oesophagus

Ingestion of caustic material is a major management problem which occurs most commonly in children. Twenty-five patients with caustic ingestion seen over a ten-year period are reported. Twelve patients had severe burns, resulting in oesophageal strictures. Of these, ten were children below six years of age (median age, 3 years). Dysphagia and vomitting were the main presenting features. Oropharyngeal burn was present in 83 percent of patients with oesophageal burns. The strictures involved the entire oesophagus in two patients, the upper third in four, the mid oesophagus in two and the lower third in four. Periodic dilatations were successful in restoring an adequate lumen in 7 patients with short strictures. Five patients required surgery. There was one death. Caustic damage to the oesophagus is preventable. Education of the public and simple measures by manufacturers of caustics are urgently needed (AU)

Acid ingestion causing pyloric obstruction

A case of gastric outlet obstruction following acid ingestion in a 21/2-year-old child is reported. The characteristic features of this injury are minor injury to the mouth, pharynx and oesophagus, and major injury to the stomach. A small amount of acid can produce considerable damage to the stomach. Therefore all patients require admission to hospital. Early barium meal examination and, if available, flexible endoscopy, will identify the extent of damage so as to avoid early discharge of patients when gastric performation is likely. Emphasis is placed on the need for public education in the prevention of ingestion of corrosive substances by children (AU)

Two unusual cases of mural endocarditis, with a review of the literature

Two unusual cases of mural endocarditis are described. The first was that of a 13-year-old boy with infected burns of the legs. Autopsy revealed mural vegetations in both ventricles and cytomegalic viral inclusions were demonstrated in the vegetations, heart muscle, and endothelial cells of various organs. This appears to be the first reported case of cytomegalic inclusion viral endocarditis. A review of the literature revealed only six previous reports of cytomegalic viral myocarditis, which was also present in this case. The second case was that of a 4-year-old girl with bronchiectasis. Autopsy revealed mural vegetations in the right ventricle. Group C beta-hemolytic steptococcus was isolated from th mural vegetations, as well as from the diseased lungs. Only two previous reports of endocarditis caused by this organism are found in the literature (AU)

Chemical burns: the Jamaican experience

Presents an analysis of chemical burns at three hospitals in Jamaica