Hyperbaric oxygen treatment for carbon tetrachloride poisoning.

Carbon tetrachloride (CCl4) undergoes hepatic reductive metabolism to trichloromethyl (.CCl3) and peroxytrichloromethyl (CCl3OO.) free radicals, toxic intermediates which may initiate hepatocellular damage. Recent investigations have demonstrated a potential role for hyperoxia and hyperbaric oxygen as therapeutic interventions for CCl4 poisoning. Elevated oxygen concentrations in vitro and in vivo reduce lipid peroxidation and hepatotoxicity. In vivo studies of hyperbaric oxygen following administration of CCl4 in a rat model have shown improved survival and decreased hepatotoxicity. Case reports of human poisoning, with potentially lethal ingested doses of CCl4, also suggest a potential role for treatment with hyperbaric oxygen. Hyperoxia may act by altering the metabolism of CCl4. These studies and case reports support the recommendation that 100% normobaric and hyperbaric oxygen should be treatment considerations for CCl4 poisoning.

Suspected cyanide poisoning in smoke inhalation: complications of sodium nitrite therapy.

A 78 year old man was found comatose, apneic, and asystolic after closed-space smoke inhalation. He was successfully resuscitated to pulse and blood pressure at the scene. A cyanide component to the poisoning was suspected and two 300 mg doses of sodium nitrite were administered, resulting in significant hypotension. Although high methemoglobin levels were not induced, when added to simultaneously obtained carboxyhemoglobin levels, the total amount of non-oxygen transporting hemoglobin remained nearly constant for about 4-1/2 hours before hyperbaric oxygen (HBO) therapy could be administered. The patient later died in multi-organ system failure. Admission whole blood cyanide level was only 0.34 mcg/mL. These sodium nitrite adverse effects can be avoided by slow intravenous infusion and by administering only recommended doses. In smoke inhalation victims with suspected cyanide poisoning, sodium thiosulfate should be administered first, and sodium nitrite withheld until after the patient is receiving HBO therapy. When available, hydroxocobalamin (which neither induces methemoglobinemia nor causes hypotension) may be the specific cyanide antidote of choice for victims of smoke inhalation.

Five cases of Thermopsis poisoning.

Various Thermopsis species are found in the foothills and plains of the Rocky Mountains. There are no reported cases of human ingestion to Thermopsis reported in the literature. We report 5 cases of ingestion of seeds or flowers where the primary symptoms were nausea, vomiting and headache of several hours duration. As few as 6 seeds produced symptoms. The common names used by parents when calling the poison center could have easily lead to misidentification and a careful history and subsequent professional identification were required to ascertain the actual plant involved.

Clinical effects of accidental levothyroxine ingestion in children.

Forty-one children, aged 1 to 5 years, who accidentally ingested levothyroxine sodium were studied. Symptoms possibly associated with the ingestion occurred in 11 patients (27%). These symptoms (tachycardia, hyperactive behavior, fever, vomiting, diarrhea, diaphoresis, and flushing) were categorized as minor and all resolved without treatment. Because observed effects were generally mild and often unrelated to either estimated amounts of hormone consumed or serum thyroxine levels, a conservative approach to patient treatment is recommended in cases of levothyroxine ingestion in children.

Assessing mistletoe toxicity.

To assess the potential toxicity of mistletoe ingestion, data were collected on 14 cases of ingestion of one to three berries or one or two leaves of American mistletoe (Phoradendron sp) from 1982 to 1985. Eleven patients ingested berries and three ingested leaves; none became symptomatic. Nine patients were observed at home without intervention except poison center telephone follow-up. Five had induced emesis, including two who were referred to emergency departments for evaluation, where no findings other than ipecac-induced vomiting were noted. Also reviewed were data on a total of 318 cases of mistletoe ingestion reported to the Food and Drug Administration Poison Control case reporting system between 1978 and 1983 (n = 177) and the American Association of Poison Control Centers national data collection system (n = 141) in 1984. The majority remained asymptomatic and no deaths were recorded. These data allow the conclusion that ingestion of one to three mistletoe berries or one or two leaves is unlikely to produce serious toxicity.

Clinical toxicology of cyanide.

Cyanide poisoning causes a high incidence of severe symptomatology and fatality. There are numerous sources of potential cyanide exposure. Without the history of cyanide exposure, diagnosis is often difficult. Treatment with supportive measures and available specific and efficacious antidotes frequently allows survival. The toxicology of cyanide, including sources, clinical features, diagnosis, and treatment, is reviewed.

Management of acutely poisoned patients without gastric emptying.

During an 18-month period, 592 acute oral drug overdose patients were studied prospectively in a controlled, randomized fashion to determine the efficacy of gastric emptying procedures in altering clinical outcome. Patients presenting on even-numbered days had no gastric emptying procedures performed, and they were compared to patients presenting on odd-numbered days who received either syrup of ipecac or gastric lavage. Patients were carefully followed for evidence of subsequent clinical improvement or deterioration after initial management. Syrup of ipecac did not significantly alter the clinical outcome of patients who were awake and alert on presentation to the emergency department (ED). Gastric lavage in obtunded patients led to a more satisfactory clinical outcome (P less than .05) only if performed within one hour of ingestion. Gastric emptying procedures in the ED for initial treatment of drug overdose are generally not of benefit unless gastric lavage is performed within one hour of ingestion in obtunded patients.

Human ivermectin exposure.

Ivermectin is a veterinary antiparasitic medication for domestic animals. Two cases of human exposure to veterinary preparations of ivermectin are reported. Patient number one accidentally self-injected ivermectin and developed nausea, pallor, and transient pain and numbness in the affected extremity. Patient number two, a 4-year-old child, ingested an unknown amount of the paste preparation and remained asymptomatic. As ivermectin is being used with increasing frequency in veterinary medicine, more human exposures may be anticipated.

Hyperbaric oxygen therapy for severe hydrogen sulfide poisoning.

The optimum therapy for hydrogen sulfide poisoning is unclear. Adjuncts used in the treatment of cyanide poisoning have been advocated because of the shared mechanism of toxicity between hydrogen sulfide and cyanide. Following success in cyanide poisoning, hyperbaric oxygen therapy (HBO) has been suggested for use in treating hydrogen sulfide poisoning. A case of severe hydrogen sulfide poisoning was successfully treated with HBO after standard therapy was apparently ineffective. HBO as a therapeutic adjunct in hydrogen sulfide poisoning and the rationale for its use are discussed.

Massive copper sulfate ingestion resulting in hepatotoxicity.

Intentional overdosage of copper salts is seen infrequently in the U.S., but is fairly common in other countries (1). Toxic blood levels can be seen after oral ingestion of as little as one gram of copper sulfate in an adult (2). We report a case of a patient who ingested 250 grams of copper sulfate, developed transient hepatic dysfunction, and recovered after the prompt administration of chelation therapy.

Comparative efficacy of injectable calcium and magnesium salts in the therapy of hydrofluoric acid burns.

Hydrofluoric acid (HF) causes severe skin burns which often progress in severity despite physiologic neutralization. The currently accepted therapy is the subcutaneous injection of calcium (Ca) gluconate to precipitate the residual free fluoride ion. Magnesium (Mg) also forms an insoluble fluoride salt and is less tissue irritating than Ca. This study compared the effects of subcutaneous injection of saline, Ca gluconate, Mg acetate (MgAc), and Mg sulfate (MgSO4) on lesions resulting from HF burns in rats. Burns treated with either Mg compound healed 3.7 +/- 1.7 days faster (p less than 0.05) developed less severe lesions (p less than 0.01) and exhibited left untreated or treated with saline. There was no difference in the incidence of infection between the study groups. The effects of burns treated with calcium were statistically similar to the control groups. This study suggests that Mg may be more effective than Ca in minimizing the duration, depth, and progression of dermal HF burns.

Selenium: childhood poisoning and cystic fibrosis.

Two cases of selenium ingestion in children are described; one child with severe cystic fibrosis died. Both children had cystic fibrosis and both had low serum chloride in association with selenium usage. Neither child was exposed to excessive heat or cold weather, factors known to salt-deplete children were cystic fibrosis, although one child was dehydrated during a summer month on initial presentation. One child had protein-calorie malnutrition, a condition known to enhance selenium toxicity in animals. We conclude that selenium is a potential hazard in its use as a health food fad for children with cystic fibrosis and in overdose ingestions. Thus selenium supplementation may have contributed to the morbidity and mortality reported here.

Phenothiazine-induced ventricular tachycardia following acute overdose.

The chronic use of phenothiazine is known to result in ventricular arrhythmias in certain patients. The occurrence of cardiac abnormalities following acute phenothiazine overdose is less well documented. Phenothiazine-induced ventricular tachycardia, when it occurs in the overdose situation, may be refractory to conventional antiarrhythmic drugs. We present a case in which the usual therapy was unsuccessful. Only after a transvenous pacemaker was inserted was the patient's condition reversed.

Podophyllin poisoning. Systemic toxicity following cutaneous application.

The toxicity of topically applied podophyllin in a 16-year-old girl is presented. Coma requiring respiratory support and major neurologic complications as well as hematologic and hepatic toxicity was observed. Therapy with a new modality, charcoal hemoperfusion, resulted in resolution of the acute toxicity, leaving a peripheral neuropathy which had not completely resolved after 4 months. The pharmacology and suggested treatment measures for the toxicity of this rarely reported agent are reviewed.