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Biomedical subjects

Lewis S Nelson

Publications and source records attributed to Lewis S Nelson.

64 records · Page 4Linked to original sources
PubMed2002

Toxicologic myocardial sensitization.

Drug-induced polymorphic ventricular tachycardia (torsades de pointes) may lead to syncope or sudden cardiac death. One mechanism by which drugs and toxins may predispose to the development of this malignant dysrhythmia is through their ability to produce myocardial sensitization. The concept of myocardial sensitization actually represents a series of events involving altered cellular repolarization produced by blockade of myocardial potassium channels. Altered potassium ion flow raises the likelihood that an ectopic beat will occur via an early afterdepolarization and simultaneously alters the myocardial tissue to make it favorable for reentrant dysrhythmias, such as torsades de pointes, to propagate. Alternatively, calcium overload of the myocyte produces ectopy by causing delayed afterdepolarizations, which if the substrate for reentry is present, will result in ventricular tachycardia. This paper discusses the mechanisms underlying the production of both the altered myocardial substrate and the afterdepolarizations.

Action Potentials↗
PubMed2002

Gabapentin withdrawal presenting as status epilepticus.

A 34-year-old male with lumbar disc disease and surgery was placed on gabapentin daily for chronic back pain. He remained on a steady dose of 8000 mg/day for 9 months, almost doubled what is considered therapeutic. He ran out of medication, was unable to refill his prescription for 2 days and presented to the emergency department in status epilepticus. There was no previous history of seizure disorder and he was on no other medications. A medical evaluation for an alternative etiology of his seizures was negative. Although gabapentin withdrawal has been previously reported and usually consists of anxiety, diaphoresis, and palpitations, this is the first reported patient with generalized seizures and status epilepticus secondary to gabapentin withdrawal.

Acetates↗
PubMed2002

The "ecstasy" hangover: hyponatremia due to 3,4-methylenedioxymethamphetamine.

3,4-Methylenedioxymethamphetamine (MDMA, or "ecstasy") has gained an undeserved reputation as a "safe" drug among its users. However, hyperthermia, rhabdomyolysis, hepatotoxicity, disseminated intravascular coagulation, long-term serotonergic neurotoxicity, and death are all associated with MDMA use. Hyponatremia is also reported, and its manifestations are frequently delayed several hours after the drug is ingested. The etiology of this hyponatremia is unclear; both the syndrome of inappropriate antidiuretic hormone release (SIADH) and free-water intoxication are advanced as explanations. We describe a 19-year-old female who presented to the emergency department with altered mental status 1 day after using MDMA. Her initial serum sodium was 121 mmol/L, and computerized tomography (CT) of her head demonstrated cerebral edema. She was treated with hypertonic saline and fluid restriction, and her serum sodium increased to 132 mmol/L over the next 24 hours. She regained consciousness completely within 48 hours of presentation and recovered uneventfully. MDMA toxicity, particularly the pathophysiology and treatment of MDMA-induced hyponatremia, are discussed.

Adult↗
PubMed2002

Complications of ultrarapid opioid detoxification with subcutaneous naltrexone pellets.

UNLABELLED: Rapid and ultrarapid opioid detoxification (ROD and UROD) centers promise quick, painless, same-day detoxification treatment for patients with opioid addiction. The goal of ROD and UROD is to provide a rapid transition from opioid dependency to oral naltrexone therapy. The patient is given general anesthesia and high-dose opioid antagonists. This induces a severe withdrawal but spares the patient the experience. In theory, the process is complete within four to five hours. The patient awakens without opioid dependency and is started on oral naltrexone. Any subsequent, persistent withdrawal symptoms are treated symptomatically. A novel, unapproved approach is to compound a pellet of naltrexone and implant it in the subcutaneous tissue. In theory, this should result in continuous therapeutic levels for this drug, and avoid issues with noncompliance. CASE SERIES: This article reports six cases of complications from the same detoxification center that performed UROD with naltrexone pellet implantation, including pulmonary edema, prolonged withdrawal, drug toxicity, withdrawal from cross-addiction to alcohol and benzodiazepines, variceal rupture, aspiration pneumonia, and death. CONCLUSIONS: The risks of this procedure are great and further studies should assess its safety and the novel use of naltrexone.

Administration, Cutaneous↗
PubMed2002

Erythropoietin overdose treated with emergent erythropheresis.

Erythropoietin (EPO) is commonly used to treat anemias secondary to renal failure, malignancy, and AIDS. Although therapeutic complications are well described, overdose is rare. A 42-y-o man with AIDS confused his instructions for self-administration of interferon and EPO and began injecting himself daily with 10,000 units of EPO for several weeks. He presented with confusion, pain in his abdomen and feet, and a hemoglobin of 23.2 g/dLwith a hematocrit of 77.1%. The patient was treated with iv fluids, phlebotomy and 2 sessions of erythropheresis which removed 898 mL and 640 mL of red blood cells, respectively; his hemoglobin remained between 12-14 g/dL and symptoms resolved. His only sequelae involved skin loss over his toes, which did not require grafting. This rare case of EPO overdose highlights the complications of essential erythrocytosis, with central nervous system, peripheral, and presumed mesenteric ischemia.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Case report and literature review of chlorine gas toxicity.

Chlorine gas exposure is uncommon in children and when it occurs usually results in mild ocular, oropharyngeal, or respiratory symptoms. Occasionally, however, chlorine gas poisoning may cause severe pulmonay toxicity. We report the case of a 14-y-old boy with a history of asthma who was exposed to chlorine gas as a result of an ill-advised science experiment. His clinical condition deteriorated over the course of several hours, and he required intubation and ventilatory support. During his hospitalization, he developed the acute respiratory distress syndrome. He was treated with positive pressure ventilation, beta-adrenergic agonists, and corticosteroids. After 19 d, he was extubated and subsequently made an excellent recovery. We discuss his case and review the etiology, pathophysiology, clinical presentation, laboratory findings, treatment and possible long-term sequelae of chlorine gas toxicity.

Adolescent↗
PubMed2002

Desiccant-induced gastrointestinal burns in a child.

Desiccants are commonly composed of non-toxic chemicals such as silica gel. A 2-y-old male unintentionally ingested the contents of a desiccant packet found in a container of imported Chinese cookies. He presented with vomiting, drooling and inability to drink. A caustic injury to his tongue and phaynx was noted. He improved over the next 12 h and was discharged a day later. The packet was found to contain caustic lime Although patients who ingest desiccant packets generally develop no clinical effects, ingestion of packets containing strong alkali may prove consequential. Providers should be aware of the potential for this toxicity before dismissing desiccant exposures as benign.

Burns, Chemical↗