PubMed HealthSearch

Biomedical subjects

W K Chiang

Publications and source records attributed to W K Chiang.

6 recordsLinked to original sources

Calcium channel blocker overdose.

A case of diltiazem overdose with significant hemodynamic compromise is presented. Multiple therapeutic modalities were attempted with limited results. Control was finally achieved with a combination of norepinephrine, dobutamine, and cardiac pacing. Invasive pulmonary monitoring parameters are reported and were important in the management of this patient. The management of calcium channel blocker overdose and the various available therapeutic modalities are discussed.

Adult

Problems affecting the liquid chromatographic quantitation of chlorhexidine digluconate in ophthalmic solutions.

A liquid chromatogrpahic (LC) assay was recommended by the Food and Drug Administration of the United States for the uptake and release study of chlorhexidine digluconate (CHDG) in ophthalmic solutions by contact lenses. The results from this and other reversed-phase LC assays of CHDG were inaccurate when the working standard and sample solution matrices were different. The error was caused by binding of the analyte onto the container surface and LC column packings. The loss of chlorhexidine due to binding was dependent upon, and very sensitive to, the counter ions in the sample solutions. Relative to water solutions of CHDG, solutions containing chloride, thiosulphate and edetate reduced the loss of the analyte, while solutions containing borate enhanced the loss. To assay CHDG reliably with reversed-phase LC, the media of the working standard and the sample solutions should be closely matched.

Chlorhexidine

Theophylline desorption from activated charcoal caused by whole bowel irrigation solution.

Whole bowel irrigation with polyethylene glycol electrolyte lavage solution has been recommended as an adjunct to traditional overdose management. Although combined activated charcoal and whole bowel irrigation could enhance the efficacy of both modalities, this improvement remains largely speculative. An in vitro experiment was designed to determine whether polyethylene glycol electrolyte lavage solution alters the adsorption of theophylline to activated charcoal. Theophylline was agitated with activated charcoal in either water or polyethylene glycol electrolyte lavage solution, at each of three activated charcoal:theophylline ratios; 1:1, 3:1, and 10:1. The concentration in the supernatant was determined by high pressure liquid chromatography, and the maximal adsorptive capacity of activated charcoal for theophylline was calculated from the Langmuir equation. The percent of theophylline adsorbed by activated charcoal in water was 16 +/- 4%, 67 +/- 5%, and 97 +/- 3% for the 1:1, 3:1, and 10:1 ratios, respectively. This was decreased to 17 +/- 5%, 37 +/- 3%, and 62 +/- 2% when polyethylene glycol electrolyte lavage solution was added. A statistical difference (p less than 0.05) occurred at the 3:1 and 10:1 activated charcoal:theophylline ratios. Similarly the maximal adsorptive capacity was decreased 23% from 264 mg/g to 203 mg/g when polyethylene glycol electrolyte lavage solution was added to activated charcoal prior to theophylline. Polyethylene glycol electrolyte lavage solution significantly decreases adsorption of theophylline to activated charcoal in vitro. In vivo studies are required to confirm these findings. If activated charcoal is to be used clinically for theophylline toxicity, the authors suggest the possibility of larger quantities of activated charcoal, and administering activated charcoal in a slurry of water before the initiation of whole bowel irrigation.

Adsorption

Substance withdrawal.

As long as drug use and abuse persist in our society, a significant number of patients with various types of drug withdrawal will present to Emergency Departments. It is imperative that we recognize the signs and symptoms of drug withdrawal and render the appropriate treatments. Although it may be easy to recognize "skid row" alcoholics, a drug abuser with track marks on his (or her) arms or with a perforated nasal septum, the executive alcoholic, the elderly patient on chronic diazepam therapy, or the "blue collar" worker using cocaine may be more common and more elusive. Because most drug abusers use and can be dependent on multiple drugs, detoxification may need to proceed with one drug or one class of drugs at a time. Although our discussion has concentrated on the acute presentation and treatment of these symptoms for the emergency physician, we recognize that the acute treatment of withdrawal symptoms is only a small but vital part of withdrawal treatment. These patients will require chronic treatment, including social and psychologic counseling. As emergency physicians, by performing our jobs of recognition, stabilization, and counseling, we will fulfill the first critical link in the treatment of these patients.

Ambulatory Care

Prospective evaluation of "crack-vial" ingestions.

The "crack" (cocaine alkaloid) epidemic has resulted in an increasing number of hospitalizations of "crack-vial body-stuffers," or patients who ingest "crack-vials" in an attempt to avoid prosecution. Management strategies for this type of ingestion are lacking because of the paucity of data. This report discusses the demographics and symptomatology of 23 patients with "crack-vial" ingestions, as well as the value of abdominal radiographs and the utility of varied strategies for decontamination in this patient population.

Adolescent