Prevalence of lead poisoning among two-year-old children in Vermont.

OBJECTIVES: The recent redefinition of childhood lead poisoning by the Centers for Disease Control and Prevention means that many more children are considered lead poisoned than previously. The primary purpose of this study was to determine how many 2-year-old children had lead levels of 10 micrograms/dL or more in a rural state. METHODS: Random samples of 334 children drawn from the birth certificate file and 350 children from Vermont Medicaid rosters submitted capillary blood specimens that were confirmed by venous tests if lead levels were 10 micrograms/dL or more. RESULTS: Participation rates were 63.9% in the birth certificate group and 66.4% in the Medicaid group. In the birth certificate sample, the percentages of children with confirmed lead levels 10 micrograms/dL or more, 15 micrograms/dL or more, and 20 micrograms/dL or more were 9.0 (95% confidence interval [CI], 6.2-12.6), 2.7 (95% CI, 1.2-5.0), and 1.5 (95% CI, 0.5-3.4), respectively. In the Medicaid sample, the corresponding percentages were 14.9 (95% CI, 11.4-19.2), 5.1 (95% CI, 3.1-8.0), and 2.0 (95% CI, 0.8-4.1), respectively. The percentage of children in the state's most urban county with lead levels of 10 micrograms/dL or more was significantly less than that in the rest of the state in both samples. CONCLUSIONS: The prevalence of elevated lead levels in 2-year-old children may be significant in rural states with old housing stock. Medicaid-enrolled children represent a readily identifiable high-risk group.

Intraosseous infusion: success of a standardized regional training program for prehospital advanced life support providers.

STUDY OBJECTIVE: To evaluate a standardized training program in intraosseous (IO) infusion for prehospital providers. DESIGN: Prospective multicenter 24-month study. SETTING: IO infusions were performed by prehospital providers from eight advanced life support units serving 14 hospitals within nine counties. PARTICIPANTS: Field advanced life support providers (paramedics and registered nurses). INTERVENTIONS: All providers participated in a one-hour standardized training session and supervised hands-on simulation. Providers completed a data sheet on all IO infusions performed. Data sheets were collected and summarized. RESULTS: One hundred thirty-four prehospital providers completed the training session and were approved to perform the procedure. Fifteen patients requiring IO infusion were encountered during the study period. Thirteen (87%) had IO infusion completed successfully. Clinical indications included 11 patients in cardiac arrest, two trauma resuscitations, one seizure, and one toxic ingestion. Patient ages ranged from 1 to 24 months. Seven patients were initially resuscitated. Four survived to hospital discharge. Procedural complications included one incidence of local fluid extravasation and one IO line that became dislodged en route. There were no complications at time of discharge in the four survivors. All procedures were performed in less than two minutes. CONCLUSION: A one-hour standardized training session was successfully used to train prehospital providers in the procedure of IO infusion. IO infusion then was implemented into their clinical practice with a satisfactory success rate and few complications.

Prehospital administration of inhaled metaproterenol.

STUDY OBJECTIVES: We conducted a study of the prehospital use of inhaled metaproterenol. DESIGN, SETTING, TYPE OF PARTICIPANTS, AND INTERVENTIONS: Advanced life support (ALS) providers were trained with a standardized curriculum to identify patients likely to benefit from prehospital inhaled metaproterenol administration. Unit doses of metaproterenol were used in a small-volume nebulizer. We prospectively included 122 patients in an initial study (71 men; age, 63 +/- 19 years) to evaluate the safety and effectiveness of metaproterenol in the field, and 150 patients (including the original 122) in an additional study to evaluate patient selection criteria. MEASUREMENTS AND MAIN RESULTS: The treatments resulted in an increase in peak flows, a decrease in respiratory rates, and no change in heart rates. In 62% of patients, the increase in peak flow exceeded 15%. Wheezing improved in 59% of the patients, worsened in 4%, and did not change in the remainder. Air entry by auscultation improved subjectively in 59% of patients. Mild tremor occurred in 8% of patients, moderate tremor occurred in 1%, and no tremor occurred in the remainder. Significant dysrhythmias did not occur. CONCLUSIONS: ALS providers correctly identified patients for this therapy. No technical problems were encountered in the field with this treatment approach. We conclude that ALS providers can be taught to identify patients likely to benefit from inhaled metaproterenol, that inhaled metaproterenol can be administered in the field, and that metaproterenol is both safe and effective when used in the prehospital setting.

An investigation of possible models for the production of progressive pulmonary fibrosis in the rat. The effects of repeated intratracheal instillation of bleomycin.

Pulmonary fibrosis is a common later sequel to damage to the lung caused by a wide variety of agents. Bleomycin is an antineoplastic drug used in the treatment of squamous cell carcinomas and lymphomas. It is known to cause pulmonary fibrosis is both man and experimental animals. Bleomycin, dissolved in saline, was given by intratracheal instillation (dose = 0.5 U/animal; dose vol. = 0.5 ml/animal) to groups of at least 5 rats. Groups received either a single dose or 2, 3 or 4 doses each given a week apart. They were then sacrificed at periods of up to 90 days after the last dose. Subsequent histology revealed varying degrees of alveolitis, type II pneumocyte hyperplasia, alterations to alveolar structure including obliteration, degeneration, collapse and enlargement with significant interstitial fibrosis. The lesion appeared to be diffusely distributed throughout the lung. After a single dose or 2 doses regression of the lesion was observed with time following dosing whereas with 3 or 4 doses of bleomycin the changes increased progressively in extent and severity. Three or more doses of intratracheal instilled bleomycin appear to be a good model of progressive pulmonary fibrosis in the rat.

Noninvasive transcutaneous cardiac pacing in prehospital cardiac arrest.

This study evaluated the efficacy of prehospital external cardiac pacing in cardiac arrest patients. From October 1984 to June 1985, 91 patients were paced. Mean time from cardiac arrest to advanced life support (ALS) intervention in this metropolitan-rural ALS system was 14.5 minutes. Electrical capture occurred in 85 (93%), mechanical capture (pulses) occurred in ten (11%), and a measurable blood pressure occurred in three (3%) of the 91 patients. Despite a high rate of electrical capture, palpable pulses were produced only in 11%, and no patients survived to be discharged from the hospital. There was no difference in the frequency of electrical capture, palpable pulses, or outcome for patients receiving pharmacologic intervention before or after pacing. Likewise there was no difference in the frequency of electrical capture, palpable pulses, or outcome for patients receiving ALS therapy within or after ten minutes of their arrest. Although we found that external cardiac pacing was easily used in the prehospital setting, pacing did not result in any increase in survival in cardiac arrest patients.

Interspecies differences in rhodanese (thiosulfate sulfurtransferase, EC 2.8.1.1) activity in liver, kidney and plasma.

Rhodanese levels have been measured in liver, kidney and plasma from a number of species. Liver activity was low in marmosets, pigeons and beagle bitches. Levels were high in rats and somewhat lower in hamsters and guinea pigs while levels in two strains of rabbits were intermediate between guinea pigs and marmosets. The relationship between hepatic and plasma rhodanese and cyanide sensitivity is discussed.

Passive smoking and thiocyanate concentrations in pregnant women and newborns.

Serum thiocyanate concentrations have been used as a marker of cigarette exposure in both smokers and nonsmokers. The authors used this measure to estimate passive exposure in low-risk healthy pregnant women at term. Three groups were compared: smokers, passive smokers, and nonsmokers. The mean thiocyanate concentration (95 mumol/L) was significantly higher (P less than .001) in smokers than in passive smokers (35.9 mumol/L) or nonsmokers (32.3 mumol/L). The maternal and umbilical mean cord thiocyanate concentrations were similar in the smoking group (95 versus 72 mumol/L). Although the umbilical cord levels in the infants of passive smokers and nonsmokers were similar (26 versus 23 mumol/L), both levels were significantly lower than those of smokers. Most important, there was an inverse relationship between umbilical cord thiocyanate concentration and birth weight (P less than .001). The authors found no evidence that passive cigarette smoke exposure resulted in higher maternal or umbilical cord thiocyanate concentrations than found in nonsmokers.

Synthesis and biological activity of 3,5-dinitro-4- and -2-(1H-purin-6-ylthio)benzoates, prodrugs of 6-mercaptopurine.

A series fo prodrug modifications of 6-mercaptopurine (6-MP) containing dinitrobenzoate ester moieties with varying chain length has been prepared. These compounds were shown to be cytotoxic in several cell culture screens and also exhibited significant activity against L1210 lymphoid leukemia in vivo. The possibility exists that the transport and distribution of these compounds in vivo will be determined, in part, by increased lipophilic character, with a consequent selective localization in lymphatic and CNS tissue.

Alleviation of narcotic withdrawal syndrome by conditional stimuli.

We systematically paired auditory, olfactory, and social stimuli with each injection of morphine in rats. We found that, when morphine was kept constant at a low dose, the external stimuli acquired the property of a conditional stimulus (CS) to cause hyperthermia which was antagonized by naloxone. In rats in which morphine doses were regularly increased to cause morphine dependence, the CS presented during withdrawal, caused reduction in withdrawal signs (wet shakes, hypothermia, aggression) and produced hyperglycemia as well as elevation of striatal homovanillic acid. CS-induced alleviation of withdrawal hypothermia was blocked by mecamylamine, phenoxybenzamine, haloperidol, benztropine or naloxone but not by cyproheptadine or propranolol.

Paradoxical absence of aggression during naloxone-precipitated morphine withdrawal.

Aggression, which is normally seen during withdrawal from narcotics, could not be produced in morphine-dependent rats by the administration of naloxone at doses which causes other signs of withdrawal. Apomorphine injected instead of naloxone was capable of producing aggression, without other withdrawal signs. Naturally occurring aggression (72-hr withdrawal) was enhanced by apomorphine and unaffected by naloxone.