Outcomes following abuse of methanol-containing carburetor cleaners

INTRODUCTION

Carbureter cleaners may contain methanol and are abused via inhalation. Toxicity resulting from the methanol component of these products is poorly described.

METHODS

We conducted a retrospective poison center chart review over a four-year period (3/98-3/02) of outcomes following methanol-containing carbureter cleaners (MCC) exposure. Inclusion criteria were: (1) use of MCC, (2) evaluation in health care facility (HCF), (3) no known co-ingestion exposure and (4) at least 12 hour follow-up.

RESULTS

33 cases were reviewed with 11 cases excluded because of significant co-ingestions. Of the remaining 22 cases the mean age was 17 [range: 14-41] years old with 90% of cases between 14 and 17 years old. Six women and 16 men were in the study. Six of 22 cases had acidosis (serum bicarbonate < or =22 mmol/L or pH < or =7.35), 100% of patients had neurological symptoms (ataxia, etc.) and 14/22 had vomiting on presentation. Three patients received treatment with ethanol (1) and fomepizole (2). All others received intravenous fluids (15) or no treatment (4). Mean serum methanol concentration was 28mg/dl [range: 0-341 with 17/22 developing acidosis. Serum methanol was obtained at a mean of 3.5 hours [range 1-7 hours] post use. All metabolic disturbances resolved within 24 hours except in one patient (41 years old) in which her disturbances resolved within 72 hours. No patient developed visual disturbances or neurological sequealae.

CONCLUSIONS

Significant toxicity following inhalation of MCC was rare with symptoms improving without aggressive care (dialysis, alcohol dehydrogenase blockade).

Scorpion envenomations in young children in central Arizona

INTRODUCTION

Centruroides sculpturatus, also known as Centruroides exilicauda or bark scorpion, is the only scorpion native to the United States whose venom produces a potentially life-threatening illness, particularly in children.

OBJECTIVES

To describe the distribution of the severity grades following scorpion envenomations, the onset of clinical signs and symptoms, the time to deterioration, and side effects of antivenom treatment in children < or = 2 yrs of age.

METHODS

Prospective case-series with the following inclusion criteria of presumed scorpion envenomation, witnessed scorpion or signs and symptoms consistent with envenomation, patient age < or = 2 yrs, and the call was received by the poison center. After data were entered prospectively, a reviewer who was blinded as to the purpose of the study reviewed the charts. A second reviewer examined 10% of the charts for accuracy in coding. Envenomation severity grades were based on a previously described scorpion grading scale and were correlated with admission rates, clinical deterioration, and outcomes. Descriptive statistics (STATA & EXCEL) were used.

RESULTS

Of the 491 charts, 483 (98%) had adequate information available. The mean age was 20.8 [range 2-24] months with 133 patients (27.5%) presenting to an emergency department (ED), 86 patients (17.8%) received antivenom, and 25 patients (5.2%) were admitted. The p-value for kappa and the 95% confidence interval (CI) for interobserver reliability kappa score was 0.69 with CI (0.44-0.95). The grade distributions were Grade I = 343 cases (71%), Grade II = 8 cases (1.7%), Grade III = 49 cases (10.1%), and Grade IV = 83 cases (17.2%). The mean time to advancement of grade was 14 min (95% CI [10.97,17.06], 99% CI [10.04,18.03]) and the median time was < 1 min (range 0-140 min). Twenty-five patients (5.2%) were admitted, of which 13 were Grade III and 12 were Grade IV. Three patients (0.6% of total), all Grade IV envenomations, were intubated (95% CI [0.0021-0.0181] or an upper limit of 8.7 patients). Antivenom was administered to 86 patients (17.8%). The mean time of abatement of symptoms following antivenom was 31 [95% CI 10-82] min vs. 22.2 h [95% CI 12-46]. There was one acute reaction (rash) to antivenom administration and 49 cases (57%) of serum sickness.

CONCLUSIONS

Clinical progression following scorpion envenomation in children < or = 2 yrs old occurred on average within 14 min of envenomation with onset almost immediately. Serum sickness occurred in 57% of toddlers receiving antivenom and typically lasted less than 3 days. Admissions were less common among patients receiving antivenom.

Snakebite envenomation in children: a 10-year retrospective review

OBJECTIVE

To describe the epidemiology, short-term outcomes, and clinical characteristics of rattlesnake bites (RSB) in children.

METHODS

This was a 10-year retrospective chart review of all patients who were <13 years old admitted to a medical toxicology referral service in a major metropolitan area of the southwestern United States with a diagnosis of RSB.

RESULTS

Sixty-six children (mean age, 6.33 years) presented to or were transferred to our center with a diagnosis of RSB. Sixty-three percent were male, and the majority of bites (71.93%) occurred on the lower extremities. Forty-nine children (85.96%) developed coagulopathies, and 50 children (87.72%) received Antivenin (Crotalidae) Polyvalent (ACP) administration. Of the 50 children receiving ACP, 19 developed an immediate hypersensitivity reaction. Five cases of morbidity resulted, but no deaths were recorded.

CONCLUSIONS

Serious morbidity is infrequent in children following RSB.

Narcotic analgesia in the acute abdomen--a review of prospective trials

Withholding administration of narcotic analgesia in patients with acute abdominal pain for fear of masking pathology is still pervasive in current medical practice. We reviewed all the prospective trials that investigated the safety, adverse affects, and ultimate outcome in patients with acute abdominal pain receiving narcotic analgesia within the emergency department (ED). No adverse outcomes or delays in diagnosis could be attributed to the administration of analgesia. Based on this research, we propose that it is safe and humane to administer narcotic pain relief to patients presenting to the ED with acute abdominal pain provided no contraindications exist.

Ventricular fibrillation following inhalation of Glade Air Freshener

Intentional hydrocarbon inhalation can be fatal. Death can be secondary to hydrocarbon's cardiopulmonary effects. We present a case of a patient who survived ventricular fibrillation after inhalation of Glade Air Freshener, which contains short chain aliphatic hydrocarbons (butane and isobutane). Unlike our case, myocardial sensitization and hypoxia are more commonly described with aromatic, halogenated or longer chain hydrocarbons.

Failure of intravenous N-acetylcysteine to reduce methemoglobin produced by sodium nitrite in human volunteers: A randomized controlled trial

STUDY OBJECTIVE

To determine whether intravenous N -acetylcysteine (NAC) produces a clinically significant decline in sodium nitrite-induced methemoglobinemia in human volunteers.

METHODS

We conducted a randomized, control crossover trial with each subject serving as his own control. Methemoglobinemia was induced with intravenous sodium nitrite (4 mg/kg) administered over 10 minutes starting at time 0. At time 30 minutes, subjects were randomly assigned to treatment with intravenous NAC for 100 minutes (150 mg/kg over 1 hour followed by 14 mg/kg per hour for 40 minutes) or administration of an equal volume of 5% dextrose in water. Each subject received the alternative treatment after an interval of at least 1 week. Blood methemoglobin concentrations were measured by multiwavelength co-oximetry at time 0, 15, 30, 50, 70, 90, 110, and 130 minutes. Area under the methemoglobin concentration-time curve (AUC) between 30 and 130 minutes was compared between groups using a 2-tailed, paired t test.

RESULTS

There were no statistically significant differences in the control and treatment groups with respect to baseline hemoglobin or methemoglobin concentrations, as well as nitrite-induced methemoglobin concentrations at the initiation of treatment (0.85+/-0.06 g/dL, 0.88+/-0.04 g/dL; mean+/-SEM; P =.31). Mean AUC for the control group (77.1+/-5.7 g x min/dL) was significantly lower than the mean AUC for the treatment group (84.5+/-4.7 g x min/dL); P =.01).

CONCLUSION

Intravenous NAC failed to enhance methemoglobin reduction in this model.

Fatal tetanus in a drug abuser with "protective" antitetanus antibodies

Tetanus is a rare disease in the United States. From 1995-1997, the average annual incidence of tetanus was 0.15/1,000,000 population. Injecting-drug users, particularly those who use heroin, are among the highest risk population for acquiring tetanus. We present a case of an injecting-drug user who was seen in the emergency department with worsening diffuse midthoracic back pain and spasms. He subsequently developed acute respiratory failure and central nervous system hypoxic injury. Serum obtained before administration of tetanus immune globulin showed a tetanus antibody titer greater than 16 times the level considered protective. Because of limited human data on the minimum protective level of neutralizing antibody, as well as reports of tetanus among individuals with "protective" antibody titers, the diagnosis of tetanus should not be excluded solely on the basis of antitetanus titers.

Incidence of immediate and delayed hypersensitivity to Centruroides antivenom

STUDY OBJECTIVE

To assess the incidence and course of immediate and delayed hypersensitivity to Centruroides antivenom.

METHODS

We performed a 12-month prospective observation study, with telephone follow-up, evaluating the incidence of anaphylaxis or anaphylactoid reactions and serum sickness after Centruroides antivenom administration. The setting for the study was a poison control center and tertiary care toxicology treatment center. Participants included all patients who received Centruroides antivenom, and no interventions were performed.

RESULTS

For immediate hypersensitivity reactions, 116 patients with grade III or IV envenomation received Centruroides antivenom; 77 of these patients were younger than 13 years. Three patients completed the infusion despite development of rash. A fourth patient with a history of atopy and asthma received epinephrine infusion and an inhaled beta-agonist for transient wheezing that quickly resolved; she was admitted for observation. Nine patients without hypersensitivity reactions were admitted for social reasons, for inappropriate sedation from drugs used before antivenom, or to rule out aspiration; all were discharged within 24 hours. The remaining 106 patients were discharged from the emergency department after resolution of symptoms. Thus 4 of 116 patients had immediate reactions. For patients with delayed reactions, 17 patients were lost to follow-up. Of 99 remaining patients, serum sickness developed in 61% (n=60), as defined by using liberal criteria. Serum sickness responded to oral steroids, antihistamines, or both; mean duration of symptoms with medication was 2.8 days.

CONCLUSION

Anaphylactic reactions are uncommon after Centruroides antivenom infusion. Self-limited serum sickness that is easily controlled with corticosteroids and antihistamines commonly follows the use of Centruroides antivenom.

Serotonin syndrome in a child after a single dose of fluvoxamine

Serotonin syndrome, a potentially fatal iatrogenic complication of psychopharmacologic therapy, is most commonly reported with combinations of serotonergic medications. Serotonin syndrome is characterized by alterations in cognition, behavior, autonomic, and central nervous system function as a result of increased postsynaptic serotonin receptor agonism. We present the first reported case of serotonin syndrome after a single dose of fluvoxamine in a pediatric patient after ingestion of a single supratherapeutic dose of fluvoxamine.

Effect of magnesium hydroxide on iron absorption following simulated mild iron overdose in human subjects

OBJECTIVE

To determine the effect of oral magnesium hydroxide [Mg(OH)2] on iron absorption after simulated iron overdose in human subjects.

METHODS

A randomized, controlled crossover study was conducted in healthy adult male human volunteers taking no medications. Subjects received an average of 5.0 mg/kg elemental iron orally followed 1 hour later by either oral administration of 4.5 g of Mg(OH)2 per g ingested elemental iron or no treatment. Serial serum specimens were obtained over the 12 hours following iron ingestion and stored at -60 degrees C until standard serum iron assay was performed. After a 2-week washout period, the subjects were enrolled in the alternative trial arm. Individual baseline diurnal variation in serum iron levels was determined over a 12-hour period on the day prior to each trial. Area under time-concentration curves (AUCs) were calculated, and the AUC due to experimental iron ingestion (deltaAUC) was determined by subtracting the baseline diurnal AUC from the experimental AUC for each subject.

RESULTS

Thirteen healthy adult male subjects were enrolled. Mean +/- SEM for deltaAUC due to experimental iron ingestion followed by treatment with Mg(OH)2, 78 +/- 23 micromol(hr)/L, was significantly less than that followed by no treatment, 144 +/- 33 micromol(hr)/L (p = 0.03 by signed rank test).

CONCLUSIONS

Magnesium hydroxide, administered 1 hour post-iron ingestion at an oral dose of 4.5 g per g elemental iron ingested, significantly reduced iron absorption during a 12-hour period following simulated mild iron overdose in healthy adult human volunteers.

Rapid reversal of life-threatening toluene-induced hypokalemia with hemodialysis

A case of toluene-induced hypokalemia, respiratory failure, metabolic acidosis, and ventricular tachycardia is presented. Hemodialysis was associated with rapid improvement in our patient.

Dexfenfluramine overdose

Dexfenfluramine (Redux), the dextro-rotatory (+) steroisomer of fenfluramine, was previously approved for the treatment of weight control in the United States. We report a case of acute dexfenfluramine ingestion characterized by coma, clonus, and respiratory failure.

The use of analgesics in patients with acute abdominal pain

Analgesics in patients with acute abdominal pain are often withheld for fear that they may change physical examination findings and thus may be unsafe. We conducted a randomized, prospective, placebo-controlled trial to investigate changes in physical examination following the administration of placebo, 5 mg, or 10 mg of morphine to 49 patients with acute abdominal pain. One patient was withdrawn secondary to inadequate documentation. Of the 48 patients who completed the trial, a statistically significant change in physical examination was noted in both groups receiving analgesics, but not in the placebo group. No adverse events or delays in diagnosis were attributed to the administration of analgesics. We conclude that physical examination does change after the administration of analgesics in patients with acute abdominal pain and that a larger study is needed to evaluate analgesic safety in this subpopulation of emergency department patients.

Approach to generalized weakness and peripheral neuromuscular disease

A large number of intellectually engaging and potentially serious neuromuscular diseases have been presented. The emergency medicine physician must be able to recognize those entities that have the potential to clinically deterioration. The evaluation of weakness requires a comprehensive, broad-based differential that is driven by the history and physical. Diagnostic testing is determined by the clinical suspicion as is the urgency for further work-up. The following are the final diagnoses of the eight illustrative cases that were presented at the beginning of this article. Case 1. This unfortunate woman had a metabolic myopathy that was only diagnosed after enzymatic analysis of a muscle biopsy. Her genetic defect, carnitine palmitoyltransferase deficiency, is unusual as it does not present until late in adolescence or slightly later in life. It is a defect in lipid metabolism in which long-chain fatty acids are unable to gain entrance into the mitochondrion for oxidative degradation. The defect is apparent only after prolonged exercise or fasting. In this patient, rhabddomyolysis led to acute renal failure that resolved without requiring temporary dialysis. Case 2. This patient had an elevated CPK-MM. Her EMG showed myopathic changes and her nerve conduction studies were normal. She had a positive test for antinuclear antibodies. A biopsy of her quadriceps muscle revealed lymphocytic infiltration of the muscle fibers that showed some focal myocyte degeneration. The diagnosis of dermatomyositis was made based on the findings noted previously and the heliotrope hue of her periorbital skin. A search for an occult neoplasm was negative. She responded moderately to a course of high-dose prednisone. Case 3. The laboratory test that confirmed this diagnosis was the potassium of 2.4 mEq/L. The remainder of the electrolytes were normal. Infusion of 20 mEq of potassium over 2 hours led to a prompt return of normal muscle strength. The final diagnosis was hypokalemic periodic paralysis. In this disease there is an inherited defect in the ability of the myocyte to maintain a normal transmembrane potential. The defect is latent until there is a precipitating factor, such as an high carbohydrate meal or prolonged immobility. There is also a form seen with thyrotoxicosis and is essentially cured when the patient becomes euthyroid. The disease is seen most frequently in Asian males, although it is reported in most ethnic groups. Prophylaxis in these patients is with acetazolamide which raises the serum potassium indirectly by causing a metabolic acidosis. Triamterene and spironolactone have also been successfully used on occasion. This patient turned out to have thyrotoxicosis as well. Case 4. This man had both cranial motor and peripheral muscular dysfunction. There was no evidence of nonmotor cranial nerve dysfunction, nor was there evidence of any peripheral sensory deficits. The diagnosis of myasthenia gravis was established by the rapid and transient response of this patient to 2 mg of edrophonium. He was found to have antiacetylcholine receptor antibodies and was also thyrotoxic. He had a stormy course requiring intubation and prolonged ventilation. Eventually, he underwent thymectomy and is stable on pyridostigmine. Case 5. Initially suspected to be hysteria, this patient and his relatives had botulism from home-canned peppers. The index case required prolonged intubation and ventilation. The patients were treated with polyvalent antiserum and gastric lavage to remove the residual contaminated food which was still in their stomachs due to the gastric atony seen with this disease. The botulinus toxin prevents the release of acetylcholine molecules from their storage vesicles in nerve terminals. Thus, this disease is the opposite of the cholinergic syndrome seen with organophosphate insecticide poisonings except that cognitive functioning is not impaired in botulism. Case 6. This is a celebrated case that took a great deal of sleuthing

Intraventricular bleeding after the use of thrombolytics in a cocaine user

Cocaine-induced myocardial infarct is a medical emergency with increasing prevalence. The efficacy of thrombolytics in patients with cocaine-induced infarcts has not been well studied. This report describes the case of a patient who presented with presumed cocaine-induced myocardial infarct. The patient was treated with intravenous thrombolysis and developed an intraventricular bleed with herniation and death. Physicians should be aware of this grave consequence in a generally young population.