Acebutolol-induced ventricular tachycardia reversed with sodium bicarbonate.

BACKGROUND: Acebutolol is a unique beta blocker that possesses cardioselectivity, partial agonist activity, and membrane stabilizing activity. Sodium bicarbonate is used to reverse the cardiotoxic effects of other drugs with membrane stabilizing activity. There have been no reported cases of acebutolol-induced ventricular dysrhythmias treated successfully with bolus sodium bicarbonate. CASE PRESENTATION: A 48-year-old man ingested approximately 6.4 g of acebutolol with ethanol (blood ethanol 61 mmol/L). There were no other coingestants identified. One hour after presentation, the patient had a cardiac arrest with the monitor showing ventricular tachycardia. Sodium bicarbonate 50 mEq intravenous push converted the patient to sinus rhythm and the blood pressure improved to 129/90 mm Hg. CONCLUSION: This case demonstrates a temporal relationship between bolus sodium bicarbonate administration and the termination of acebutolol-induced ventricular tachycardia.

Pilot neonatal screening program for lysosomal storage disorders, using lamp-1.

We have demonstrated that the lysosome associated membrane protein (LAMP-1) is elevated in plasma from approximately 70% of lysosomal storage disorder patients. As part of the development of a newborn screening program for lysosomal storage disorders we have developed a first tier screening assay based upon the level of LAMP-I in blood spots taken from newborn Guthrie cards. To determine the effectiveness of the first-tier marker a prospective pilot Guthrie neonatal screening program for the identification of LSD was commenced in April 1998. Prior to commencement of the pilot program ethical approval was obtained and information leaflets regarding the neonatal screening of LSD were distributed to parents at the time of their infant's Guthrie collection. The LAMP-1 assay utilizes a chicken polyclonal and a mouse monoclonal in a sandwich time resolved fluorescent immunoassay. LAMP-1 blood-spot calibrators and quality control specimens were developed and shown to be stable and reproducible. To date 11,183 infants have been screened using LAMP-1. The population distribution is described with a median and 98th percentile of 220pg/l whole blood and 483microg/l whole blood respectively. Acceptable CV% for intra and inter assay of 8.9% and 10% respectively were obtained.

Acute digoxin overdose in a newborn with renal failure: use of digoxin immune Fab and peritoneal dialysis.

Digitalis intoxication is a common problem, mainly because of the narrow margin of safety of digoxin. These patients may have concomitant renal failure. In patients who have renal failure and who have been treated with digoxin-Fab, the elimination of the digoxin-Fab complex is significantly delayed, and there is a risk of dissociation of the complex with rebound of free digoxin and recurrence of toxicity. The high molecular weight of digoxin and digoxin-Fab complex prevents its elimination by hemodialysis or continuous arteriovenous hemofiltration. A 3-day-old newborn with digoxin overdose and acute renal failure was treated with digoxin immune Fab and peritoneal dialysis. Low levels of total digoxin were measured in the dialyzate, indicating poor elimination of the digoxin-Fab complex through peritoneal dialysis.

Neonatal screening for cystic fibrosis using immunoreactive trypsinogen and direct gene analysis: four years' experience.

OBJECTIVE: To assess the performance and impact of a two tier neonatal screening programme for cystic fibrosis based on an initial estimation of immunoreactive trypsinogen followed by direct gene analysis. DESIGN: Four year prospective study of two tier screening strategy. First tier: immunoreactive trypsinogen measured in dried blood spot samples from neonates aged 3-5 days. Second tier: direct gene analysis of cystic fibrosis mutations (delta F508, delta I506, G551D, G542X, and R553X) in samples with immunoreactive trypsinogen concentrations in highest 1% and in all neonates with meconium ileus or family history of cystic fibrosis. SETTING: South Australian Neonatal Screening Programme, Adelaide. SUBJECTS: All 88,752 neonates born in South Australia between December 1989 and December 1993. INTERVENTIONS: Neonates with two identifiable mutations were referred directly for clinical assessment and confirmatory sweat test; infants with only one identifiable mutation were recalled for sweat test at age 3-4 weeks. Parents of neonates identified as carriers of cystic fibrosis mutation were counselled and offered genetic testing. MAIN OUTCOME MEASURES: Identification of all children with cystic fibrosis in the screened population. RESULTS: Of 1004 (1.13%) neonates with immunoreactive trypsinogen > or = 99th centile, 912 (90.8%) had no identifiable mutation. 23 neonates were homozygotes or compound heterozygotes; 69 carried one identifiable mutation, of whom six had positive sweat tests. Median age at clinical assessment for the 29 neonates with cystic fibrosis was 3 weeks; six had meconium ileus and two had affected siblings. 63 neonates were identified as carriers of a cystic fibrosis mutation. Extra laboratory costs for measuring immunoreactive trypsinogen and direct gene analysis were $A1.50 per neonate screened. CONCLUSION: This strategy results in early and accurate diagnosis of cystic fibrosis and performs better than screening strategies based on immunoreactive trypsinogen measurement alone.

Cyanide and methemoglobin kinetics in smoke inhalation victims treated with the cyanide antidote kit.

STUDY OBJECTIVE: To evaluate serial cyanide, methemoglobin, and carbon monoxide levels in smoke inhalation patients. SETTING: Regional poison center and regional toxicology treatment center. PARTICIPANTS: Seven critically ill smoke inhalation patients referred to the regional poison center. INTERVENTIONS: Peak level and half-life were determined by obtaining serial carboxyhemoglobin, cyanide, and methemoglobin levels. RESULTS: The mean observed half-life of cyanide was 3.0 +/- 0.6 hours. Methemoglobinemia was evaluated in four patients after sodium nitrite administration. The peak measured methemoglobin levels (mean, 10.5% +/- 2%; range, 7.9% to 13.4%) did not occur until a mean of 50 minutes (range, 35 to 70 minutes) following administration of sodium nitrite. The total oxygen-carrying capacity reduced by the combination of carboxyhemoglobin and methemoglobin was never more than 21% (range, 10% to 21%) in this series. CONCLUSION: The administration of sodium nitrite to smoke inhalation patients in the presence of concomitant carbon monoxide poisoning may be relatively safe.

Modifying an enzyme immunoassay of immunoreactive trypsinogen to use time-resolved fluorescence.

A coated microtiter-well, enzyme-linked immunometric assay for quantifying immunoreactive trypsinogen in dried blood spots was modified to use time-resolved fluorescence of europium in place of end-point enzymatic color development as the quantification step. The streptavidin-horseradish peroxidase and color development solutions supplied as packaged reagents were replaced by europium-labeled avidin, and the signal was developed with commercially available enhancement solution and read by time-resolved fluorescence. The change of label from enzyme to europium increased the dynamic range of the assay by about 5-fold, reduced the detection limit 10-fold, and halved the intra- and interassay imprecision. The improved analytical precision and stability of the modified assay resulted in a more precise description of the population distribution of immunoreactive trypsinogen values in newborns, showing less variance in the upper centiles. This effect is of paramount importance when using this assay for neonatal screening for cystic fibrosis.

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.

Treatment of accidental digital injection of epinephrine.

The use of epinephrine auto-injectors for prehospital treatment of severe allergic reactions has become increasingly popular in recent years. Anxiety when patients are called on to use these spring-loaded devices may lead to complications. We present the case of a 28-year-old woman who accidentally injected epinephrine 1:1,000 solution 0.3 mL into her right index finger with an automatic epinephrine injector. The approach to the treatment of these complications has been varied in the literature, including local sympathectomy, topical nitrates, and either local or intra-arterial phentolamine. This potentially disabling case of epinephrine-induced vasospasm of digital arteries was treated successfully with local infiltration of phentolamine.

Near-fatal intoxication by 1, 1, 1-trichloroethane.

This report describes a case of near-fatal intoxication following accidental exposure to 1, 1, 1-trichloroethane in a child. This solvent, generally safe, is widely used to 1, 1, 1-trichloroethane in a child. This solvent, generally safe, is widely used in industrial and domestic preparations. Exposure to high levels of vapor can result in respiratory depression and/or fatal dysrhythmias. Treatment is generally supportive. Ventilation is maintained to enhance respiratory excretion.

Role of medical teams in a community disaster plan.

In London, Ont. two mock disaster exercises have indicated the need for re-evaluating the role of medical disaster teams. To coordinate and direct these teams a medical on-site coordinating team, composed of three emergency physicians with an expanded and more clearly defined role, was formed. The role of the triage teams deployed from the hospital to assess and resuscitate casualties is reviewed in detail. In addition, the communication systems, availability and deployment of medical supplies, identification of medical personnel and tagging of casualties are discussed. Because a mass casualty episode is possible in any community, disaster planning and clear outlining of the role of medical disaster teams are needed.