Alert: perioperative neonatal methemoglobinemia.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to W Banner.
Explore the source record for details and available documents.
We treated two cases of severe envenomation by the scorpion Centruroides exilicauda. The first infant was treated with a species-specific scorpion antivenom, which produced a delayed but dramatic return of all vital signs to normal. A second infant was treated with two doses of intravenous propranolol hydrochloride and had a rapid, dramatic decrease in heart rate but only gradual resolution of neurologic symptoms. These cases demonstrate the severe symptoms of envenomation by this scorpion in the infant and show two possible treatments.
Explore the source record for details and available documents.
A case of acute methylmercury ingestion was treated sequentially with oral D-penicillamine, hemodialysis during N-acetylcysteine (NAC) infusion, and 2,3-dimercaptopropane sulfonate (DMPS) an experimental oral agent. Urinary organic mercury elimination rate increased almost 40-fold during and 84-fold after hemodialysis with NAC infusion, compared with elimination during initial D-penicillamine therapy. Mean clearance during hemodialysis was only 13 ml/min with an extraction rate of 3.7 mcg/min. Although whole blood mercury concentrations decreased from 568 to 265 ng/ml during dialysis, a rebound to 525 ng/ml occurred. A total of 1.6 mg mercury was renally eliminated during hemodialysis and in the following 24 hours. A total of 3.3 mg of predominantly organic mercury was renally eliminated during 18 days of combined therapies. Since renal elimination of inorganic mercury is seen with chronic methylmercury poisoning, the high ratio of organic to inorganic mercury in urine supports the acute nature of this exposure. DMPS was begun on day 4 and during the two weeks of administration whole blood concentrations fell by 15% to 355 ng/ml. An expected decrease in elimination half-life to 10 days was not observed during DMPS therapy, possibly due to concurrent administration of vitamins containing zinc and copper. The amount of methylmercury ingested was estimated as 45 mg, based on a post-distribution blood concentration of approximately 450 ng/ml. The patient developed no symptoms of methylmercury poisoning during the one year after the episode. We conclude that NAC may be useful to enhance renal elimination of methylmercury and merits further investigation as a potential binding agent to reduce the body burden of methylmercury.
A retrospective survey of 1,135 telephone calls during 1980 and 1981, reporting scorpion envenomation to the Arizona Poison and Drug Information Center, was reviewed. Of these, 438 calls identified Centruroides exilicauda as the offending scorpion on the basis of description of the arthropod and consistency of physical findings and clinical course. Envenomation by C exilicauda occurred primarily in adults during the summer and early fall months of the year. Although most patients (92%) were treated at home with conservative therapy, 8% of patients either came to or were referred to a medical facility. Children younger than 5 years were frequently brought or were referred to either emergency care or inpatient hospital care. We conclude on the basis of this series that despite the historical reputation of lethality associated with envenomation by C exilicauda, most envenomations by this scorpion are relatively minor. The other important observation was that children younger than 5 years appear to be particularly prone to severe toxicity.
Acute ingestions of imidazoline compounds, including clonidine hydrochloride, are a recognized clinical entity. The signs and symptoms of this overdose superficially resemble those of opiate intoxication, leading to attempts to reverse this poisoning with naloxone hydrochloride. Despite previous descriptions of success using naloxone in acute clonidine poisoning, five cases of acute pediatric ingestions of clonidine ranging from mild to severe occurred in which naloxone hydrochloride in doses up to 0.1 mg/kg was unsuccessful in reversing the signs and symptoms of this intoxicant. Although naloxone can be safely administered to children who ingest clonidine to distinguish them from those who are intoxicated by opiates, it is not therapeutically useful to use naloxone to reverse poisoning with this class of agents.
The major cause of mortality and morbidity associated with the ingestion of aliphatic hydrocarbon products is related to pulmonary aspiration. Despite the high frequency of the ingestions, there is little documentation of nonpulmonary toxic effects of petroleum distillates. Two cases of gasoline aspiration/ingestion that resulted in probable intravascular hemolysis are reported. In one of these cases, the patient also manifested a consumptive coagulopathy, acute renal failure and elevation of transaminase enzymes. With modern intensive pulmonary care, the outlook for patients with petroleum distillate aspiration is good, but any documented extrapulmonary manifestations of this condition may be important in the overall management of these patients.
A fatal case of oral ingestion of potassium dichromate is presented. Following an initial presentation of abdominal pain and vomiting, the patient had a rapid progression to coma with the development of methemoglobinemia, coagulopathy, gastrointestinal hemorrhage, and respiratory distress syndrome. A blood concentration of chromium on admission was 5,800 mcg/dL, 80% of which was found to be in the intracellular fraction. Supportive treatment was also initiated as a four-hour period of hemodialysis followed by a one-hour period of charcoal hemoperfusion. Neither of these treatment modalities was found to significantly remove chromium from whole blood and neither seemed to affect the progression or outcome of this intoxication. We conclude that the ingestion of potassium dichromate is highly toxic and may rapidly lead to death. Hemodialysis and charcoal hemoperfusion appear to have little role in the management of chromium intoxication.
A variety of common pediatric emergencies were created in anesthetized cats to provide pediatric house officers and practicing physicians with an opportunity to refine diagnostic and management skills in a controlled environment under supervision. We describe the format of the animal model drill, outline protocols for stimulating pediatric critical care emergencies, and present preliminary evaluation data from a continuing medical education workshop and from house staff drills regarding the efficacy of the program.
The method by which serum osmolality is measured can significantly affect the result if certain volatiles or solvents are present in the specimen. Commonly available solvents and alcohols were added to aliquots of pooled human serum to produce toxicologically relevant concentrations. Increasing concentrations of carbon tetrachloride, chloroform, mono-n-butyl ether (butyl cellosolve), 1, 1,1 trichloroethylene, toluene, and xylene did not change vapor pressure (VP) or freezing point depression (FPD) osmolality. Acetone, ethanol, isopropanol, and methanol in increasing concentrations produced a linear increase in FPD osmolality, but no change in VP osmolality. Only ethylene glycol produced a linear increase in VP and FPD osmolality across the range of concentrations studied. Despite the excellent correlation between osmolality and ethanol concentration in prepared serum samples, this relationship could not accurately predict patient ethanol concentrations from FPD osmolality. The osmolal gap, "delta" osmolality, (measured FPD minus calculated osmolality) did not correlate with the difference between measured FPD and VP osmolalities. Patient ethanol levels could not be predicted with accuracy using an equation based on the osmolal gap or "delta" osmolality.
Explore the source record for details and available documents.
To our knowledge, the clinical course of acute caffeine poisoning in neonates has not been previously reported. Three full-term infants manifested CNS irritability after the parenteral administration of large doses of caffeine and benzoate sodium injection in the delivery room for respiratory depression. The infants received caffeine in doses that ranged from 36 to 136 mg/kg. On arrival in a regional newborn center, they exhibited one or more of the following symptoms: tachypnea, fine tremor of the extremities, opisthotonus, tonic-clonic movements, and nonpurposeful jaw and lip movements. The overdose of caffeine produced a clinical picture that suggested neonatal seizures and prompted therapy with anticonvulsants. A fourth infant (premature) attained a high plasma caffeine concentration, but this infant's symptoms were altered by intraventricular hemorrhage. The combination of caffeine overdose and perinatal asphyxia may precipitate or increase seizure activity in the neonate. Recognition of the potential toxic effects of caffeine overdose should guide patient care and stimulate further study to establish appropriate use of caffeine in the newborn infant.
Despite the indications of previous case reports and standard references, peritoneal dialysis did not appreciably enhance the elimination of phenytoin in our patient. In view of our observations, the effectiveness of peritoneal dialysis for phenytoin poisoning should be seriously questioned. A careful reassessment of the efficiency of peritoneal dialysis for phenytoin should be performed and should consider the possible role of phenytoin metabolites contributing to toxicity. Until well-controlled studies support the use of any dialytic procedure for phenytoin overdosage, the management of these patients must rely on general measures to minimize absorption of the drug and on supportive treatment as indicated by the patient's condition.
The pharmacokinetics of nafcillin were studied in 13 premature neonates with suspected sepsis. The mean weight of the infants studied was 1.19 kg (range, 0.73 to 2.21 kg). Infants less than 7 days of age were given 100 mg of nafcillin per kg per 24 h (every 12 h), and infants more than 7 days of age were given 100 mg of nafcillin per kg per 24 h (every 8 h). Blood samples were obtained before the first dose on day 3 of therapy and at 0.5, 1.5, 3, and 6 h thereafter. Nafcillin concentrations were measured by a microbiological assay. A mean volume of distribution of 326 ml/kg and an elimination rate constant of 0.2040 h-1 were obtained in 10 patients less than 21 days of age. Three patients from 24 to 68 days of age had a mean volume of distribution of 303 ml/min and a mean elimination rate constant of 0.3944 h-1 (P less than 0.05). These data suggest that doses of nafcillin lower than those currently recommended may be adequate to achieve desired peak plasma levels of approximately 75 microgram/ml in infants with low birth weights.
Explore the source record for details and available documents.
The effects of a loading dose of 15 mg/kg phenytoin by iv infusion on the serum levels of insulin, glucagon, and glucose were investigated in five fasting healthy male volunteers between the ages of 23 and 35 years. Serum glucose concentrations rose immediately after the infusion of phenytoin followed by a significant increase in serum insulin values (P less than 0.05). A slight elevation in mean glucagon concentrations after the infusion was not statistically significant. Further studies are indicated to determine whether phenytoin as used in the treatment of status epilepticus may aggravate the hyperglycemia associated with seizures.
The role of the clinical toxicologist in the neonatal nursery may be an extremely important one in the evaluation of epidemic-like toxic reactions occurring from: (a) the inappropriate use of medications; (b) the accidental contamination of parenterals; and (c) the introduction of relatively new products into the nursery environment. The newborn with high respiratory demands, thin epidermis with a large surface area to body mass ratio, and nutritional support being derived completely from parenteral sources provides a great number of routes of entry for the introduction of toxins. In approaching these problems, the clinician needs a structured approach in considering the impact of the route of administration, the contents of the product and the ability of the newborn to eliminate the toxin in question. In addition, some knowledge of the specialised structures and diseases of the newborn is required to adequately analyse the impact of a potential toxin on newborn disease processes. What we normally consider as adverse drug reactions are extremely rare in the neonate. Hypersensitivity phenomenon and the classic non-dose-related side effects described in adults are rare occurrences. This makes it a challenge for the clinical toxicologist to analyse and attempt to identify a toxic substance in the nursery. Having identified a toxin in the newborn, treatment may be complicated by the inability to use many of the standard forms of therapy, e.g. activated charcoal, diuresis, and extracorporeal removal. The lack of practicality of these procedures increases the necessity for good supportive care. Exchange transfusion, rarely considered in older children and adults, may offer the only viable option for rapid removal of a drug.
Explore the source record for details and available documents.