Tricyclic antidepressants in red cells and plasma: correlation with impaired intraventricular conduction in acute overdose.

OBJECTIVE: Tricyclic antidepressant levels in red blood cells and plasma in acute overdose and their association with cardiotoxicity were studied. METHODS: This was a prospective study in 15 patients with acute tricyclic antidepressant overdose. Tricyclic antidepressant parent compounds and metabolites were measured in red blood cells and plasma, and tricyclic antidepressant levels were correlated with ECG indexes of toxicity. RESULTS: Plasma levels of the parent compounds were higher than their red blood cell levels on admission (mean +/- SD, 691 +/- 409 and 337 +/- 220 ng/ml, respectively). Admission metabolite levels were higher in red blood cells than in plasma (264 +/- 180 and 190 +/- 164 ng/ml, respectively). QRS duration and the red blood cell levels of the metabolites were significantly correlated at the time of admission (r = 0.77, p < 0.01), as well as at 6 to 10 hours (r = 0.74, p < 0.01). CONCLUSIONS: In acute overdose, a shift of tricyclic antidepressants from plasma to red blood cells and increased levels of red blood cell metabolites reflect tissue redistribution of the drug. Tricyclic antidepressant red blood cell metabolites are the best markers for impaired intraventricular conduction.

Occult carbon monoxide poisoning: validation of a prediction model.

Headache and dizziness are early symptoms of carbon monoxide poisoning, occurring at carboxyhemoglobin levels of greater than 10 percent. Previously, it was shown that among patients presenting to an emergency department during the winter with headache or dizziness, an algorithm for obtaining carboxyhemoglobin levels on patients who used gas stoves for heating purposes or who had similarly affected cohabitants correctly identified all patients with carboxyhemoglobin levels greater than 10 percent. To test the validity of this retrospectively derived rule, 65 patients were studied who were unaware of any carbon monoxide exposure and who presented during the winter of 1986-1987 with headache or dizziness. The algorithm correctly identified three of four patients with carboxyhemoglobin levels greater than 10 percent (sensitivity = 75 percent) and correctly excluded 45 of 61 patients with lower levels (specificity = 74 percent). The presence of symptomatic cohabitants alone was an equally sensitive (75 percent) but more specific (90 percent) marker for elevated carboxyhemoglobin levels. When data from the two cohorts were combined, stepwise multiple regression identified number of cigarettes smoked daily (F = 8.66) and concurrently symptomatic cohabitants (F = 34.71) as significant predictors of the carboxyhemoglobin level. It is concluded that a retrospectively derived rule correctly identified most cases of occult carbon monoxide poisoning when applied prospectively, and that the presence of similarly affected cohabitants was the most reliable marker for a carbon monoxide-mediated illness.

Acute lupus pneumonitis in the postpartum period: a case history and review of the literature.

A patient is described who developed acute lupus pneumonitis in the puerperium. The difficulty in arriving at this diagnosis and the confusion with infectious etiologies of postpartum illness is described. Other manifestations of pulmonary disease in systemic lupus erythematosis are discussed, and the literature regarding acute lupus pneumonitis in the postpartum period is reviewed.

Serious toxicity in a young child due to ibuprofen.

An 18-month-old male presented to the emergency department (ED) for evaluation of lethargy and apnea. Four hours before presentation, the patient was found with an empty bottle of ibuprofen, an ingestion of as much as 7.2 grams (600 mg/kg). The ED course was remarkable for a 30-second tonic-clonic seizure. Laboratory analysis was notable for metabolic acidosis. Four-hour and 7.5-hour serum ibuprofen levels were 640 and 39 microg/mL, respectively. Following treatment, the patient improved and was extubated the next morning. While metabolic acidosis has been frequently described at doses exceeding 400 mg/kg, seizures occurring early in the course of ibuprofen toxicity have been rarely noted.

Approach to the poisoned patient.

Routine poison management involves the following: (1) stabilization, (2) toxidrome recognition, (3) decontamination, (4) antidote administration, (5) enhanced elimination of toxin, and (6) supportive care. Stabilization involves airway, ventilation, and circulation support. In the patient with altered mental status, oxygen, naloxone, glucose, and thiamine should be administered. Symptom complexes that relate to specific classifications of toxins are referred to as toxidromes. Emesis by means of syrup of ipecac is rarely used for in-hospital gastric decontamination. Activated charcoal is a useful adsorbent for gastric decontamination. Whole bowel irrigation is useful for iron, lead, and lithium poisoning and for the body packer phenomenon. Enhancement of elimination may involve multiple doses of activated charcoal, hemodialysis, or charcoal hemoperfusion.

Environmental injuries.

Environmental injuries and illnesses can happen in home, work, or recreational settings. The variety and severity of these injuries might require the clinician to call on skills from internal medicine, emergency medicine, and toxicology. Diseases of thermoregulation are hypothermia and hyperthermia. In each instance, treatment is based on the need to restore the patient's core temperature to normal and on monitoring for complications. The victim of a fire might suffer inhalation injury in addition to burns, and it is more likely that the inhalation injury will be fatal. Oxygen deprivation and inhalation of irritant or asphyxiant chemicals contribute to injury. Toxic plants can be the source of poisoning emergencies, especially in children. Misinformation and myths that surround common plants can create diagnostic problems (i.e., which plants really are toxic and require emergency measures). Venomous marine organisms can cause a wide range of injury, from cutaneous eruption to fatal envenomation. Most are encountered in a recreational setting, such as water sports, but keepers of home aquariums are subject to stings from venomous fish. Lightning injury can present many diagnostic and treatment dilemmas. An important point in this regard is that lightning injury and high-voltage electrical injury are different in pathology and require different approaches for treatment. A discussion of electrical, chemical, and thermal burns makes such differences apparent.

Selected topics related to occupational exposures.

The auditory and nonauditory effects of noise can be quite profound, affecting approximately 15 to 20 million Americans. As with most occupational toxins, recognition and careful assessment of noise exposure are the foundation on which preventive measures and treatment are based. Dosimeters can measure noise exposure over specific time periods. Pure tone air conduction audiometric monitoring should be performed on an annual basis in workers at risk for significant noise exposure. Occupational infectious disease involves far more than hepatitis and tuberculosis. Periodic fever, dermatologic manifestations and other symptoms peculiar to a specific disease may be important clues to an occupationally related exposure. Whereas strict attention to hand washing and isolation are cornerstones of prevention, use of protective gear is mandated in certain situations. Zoonotic disease, agriculture exposure, water transmission, and biologic contaminants in buildings can be important but subtle exposures sources. Recognition of these infections often depends on the alertness of the primary care giver.

Meconium analysis for cocaine: a validation study and comparison with paired urine analysis.

We established the validity of a drug-screening method to detect the presence of cocaine or benzoylecgonine or both in meconium and then undertook an analysis of results from urine and meconium specimens obtained concurrently from neonates within 3 days of birth. Meconium specimens from 82 consecutive newborns were analyzed using fluorescence polarization immunoassay (FPIA), Kinetic Interaction of Microparticles in Solution (KIMS), and gas chromatography-mass spectrometry (GC-MS). Each meconium specimen was analyzed by all three methods. Fifty-four paired urine and meconium specimens were obtained over a 13-month period from a neonatal intensive care unit. Urine drug testing was performed by immunoassay (enzyme multiplied immunoassay [EMIT] technique), whereas meconium specimens utilized FPIA with GC-MS confirmation on all but one specimen (due to insufficient quantity). Ten true positives were found by GC-MS, 10 positives were found by FPIA, and 70 positives were found by KIMS. Of the 54 paired samples, 39 samples tested negative for cocaine in both urine and meconium; four specimens were positive by both routes; 10 specimens were negative in urine but positive in the meconium; and one specimen tested positive in urine but negative in the meconium. Thus, 9.3% of the urine specimens tested positive, and 25.9% of meconium samples tested positive (p = .011; McNemar's Test). We conclude that screening meconium specimens by FPIA followed by GC-MS confirmation of screened positives yields highly accurate determinations of the presence of cocaine or benzoylecgonine or both in meconium and that testing of meconium for cocaine and its metabolites is more sensitive than testing of urine.

Endotracheal drug administration in the critical care setting.

Administration of drugs through an endotracheal tube has been evaluated in a number of animal models. In addition, the technique has been utilized in humans as reported in several published cases. A review of endotracheal drug administration with emphasis on application to the critical care setting is presented.

Detection of anticardiolipin antibody in patients with cocaine abuse.

Anticardiolipin antibody, an immunoglobulin that binds negatively charged phospholipids, is considered to be an in vitro inhibitor of clot-based coagulation procedures. We adapted an enzyme immunoassay using stationary cardiolipin antigen to compare anticardiolipin antibody activity in the plasma of 44 cocaine abusers with its activity in the serum of 72 blood donors and a sample of 203 random specimens from healthy volunteers. Activity of 20 of the 44 abusers and 43 of 203 random specimens exceeded the donor control reference range. Patients using intravenous cocaine were more likely to have elevated activity than those who inhaled (P less than 0.05). Of 7 patients who had seizures or thromboembolic disorders, 5 were anticardiolipin antibody positive. Enzyme immunoassay may have predictive value for ischemic disease in cocaine abusers.

Effects of nonparticipation in trauma center system on emergency department utilization.

The University of Illinois Hospital (UIH) serves an inner-city urban population in one of the highest crime rate districts in Chicago. On May 20, 1986, the city's Level I Trauma ordinance took effect with the University of Illinois Hospital declining to participate. To measure the impact of the ordinance on a nonparticipating hospital, we undertook a retrospective analysis of our trauma patient utilization statistics. Consecutive monthly patient census data of 71 months was compiled with emphasis on patient presenting complaints and related subspecialty evaluation. We observed significant decreases of patients presenting with head injuries, fractures, and animal bites as well as with major trauma, minor trauma, and general surgery hospital admission. The final disposition of the patients arriving by ambulance was consistent with the observed decrease in major traumatic conditions and in minor traumatic conditions. However, the mean number of patient presentations per day (ppd) admitted to regular medical or surgical beds decreased from 2.70 ppd to 2.30 ppd while the mean number of ppd sent home increased from 2.64 ppd to 3.49 ppd. These data suggest that loss of trauma center status designation has a profound effect on utilization of emergency departments not participating in the trauma system. Nonparticipation appears to be associated with a significant decrease in utilization rates for major and minor trauma patients and a significant increase in the number of patients discharged who had arrived by the Chicago Fire Department Paramedic System (CFD). This effect on the emergency department extends to utilization of inpatient services.

Outpatient toxicology clinic experience of patients with hip implants.

CONTEXT: With regard to biological effects, the increasing number of early failure of metal-on-metal (MoM) hip arthroplasties and possible parenteral exposure to orthopedic metal alloys have caused concern for patients and providers alike. OBJECTIVE: We sought to characterize our outpatient clinical experience of patients with MoM and other forms of hip implants and associated serum/blood chromium and cobalt levels, with a focus on possible systemic sequelae. METHODS: This was an observational and retrospective chart review of consecutive patients presenting to two outpatient medical toxicology clinics from January 1, 2010-June 1, 2012 with history of hip implants. Presenting signs, symptoms, and interventions were reviewed. Available cobalt and chromium levels were summarized as median concentration with interquartile range. RESULTS: A total of 39 patients were analyzed; of the 39 patients, 26 had MoM hip implants while 13 did not. Twelve patients exhibited no symptoms and nine sought evaluation for fatigue while two other patients had been previously diagnosed with fibromyalgia. Tinnitus/hearing loss was also a frequent complaint noted in 12 patients (one presenting complaint), however there was no difference between the incidence of this symptom between the MoM and non-MoM groups. Three patients were provisionally diagnosed with demyelinating neuropathy with one patient demonstrating marked (subjective and objective) improvement after revision. Patients with MoM arthroplasties generally exhibit an approximately tenfold increase in metal ion levels than traditional arthroplasties. Finally, 20 (51.2%) patients had replacement or revision of their hip implant with subsequent decreases in metal ion levels. DISCUSSION: A majority of our patients had minor symptoms (fatigue and muscle aches) or no symptoms (n = 23 or 59%). Documented peripheral neurotoxicity is uncommon. The decision for hip revision solely for toxicologic reasons is rare and usually involves a multidisciplinary approach. CONCLUSION: Most patients seeking toxicologic referral may be minimally symptomatic and seek guidance regarding elevated blood or serum metal ions; however, solely toxicologic-based interventions are unusual. Revision was associated with a decrease in metal ion levels; however, subjective complaints did not correlate with metal ion levels.

Oral labetalol in hypertensive urgencies.

The response to incremental doses of oral labetalol in 16 patients with hypertensive urgencies is presented. After inadequate blood pressure control with 20 mg of intravenous furosemide, each patient received a 300 mg oral dose of labetalol. Subsequent oral doses of labetalol, 100 mg, were administered at 2-hour intervals, if the diastolic blood pressure remained greater than 100 mm Hg. The maximum dose of labetalol per patient was 500 mg. Five patients required only the initial 300 mg dose of labetalol. Two patients required further therapy for satisfactory blood pressure control. Mean arterial pressure fell from 156 +/- 12 mm Hg to 123 +/- 14 mm Hg.

Carbon monoxide levels in cardiac patients in an urban emergency department.

Arterial carboxyhemoglobin (COHb) levels of patients who presented to an emergency department with cardiopulmonary complaints were determined. The purpose of the study was to see whether COHb levels of these patients indicated an acute risk factor in the severity of exacerbation of their cardiac disease. Factors known or thought to increase COHb levels (smoking and arrival by ambulance, for example) were correlated with COHb levels and final diagnoses of myocardial infarction, exacerbation of stable angina or congestive heart failure, asthma, and chronic obstructive pulmonary disease. Statistically significant increases in COHb were found in patients admitted to the intensive care unit and with proven myocardial infarction over a control group. However, these differences could be accounted for by smoking alone or by instrumental margin of error and were not thought to be related to ambient urban carbon monoxide.

Treatment of ciguatera fish poisoning with amitriptyline and nifedipine.

Ciguatera fish poisoning is the most common fish poisoning in the United States. Symptoms involve the gastrointestinal, cardiovascular and neurological systems. No known treatment exists. We explore the therapeutic effect of amitriptyline in two patients and nifedipine in one patient. Amitriptyline demonstrated resolution of most symptoms except for heat/cold reversal in one patient and heat/cold reversal, pruritus and headache in the second patient. We then used nifedipine in the second patient and noted only the resolution of his headaches. We recommend further study of these agents for the treatment of ciguatera fish poisoning.