Biomedical subjects

Bernard Yu-Hor Thong

Publications and source records attributed to Bernard Yu-Hor Thong.

4 recordsLinked to original sources

PubMed2004

Anaphylaxis during surgical and interventional procedures.

OBJECTIVE: To describe the current evidence-based knowledge of the causes, diagnostic evaluation, and treatment of patients with anaphylaxis associated with surgical and interventional procedures. DATA SOURCES: Articles published between 1966 and 2003 were identified in MEDLINE using the keywords anaphylactoid, anaphylaxis, anesthetics, antibiotics, cephalosporins, contrast media, colloids, flow cytometry, hypersensitivity, latex, neuromuscular depolarizing agents, neuromuscular nondepolarizing agents, penicillins, radioallergosorbent test, skin test, and vancomycin. Additional studies were identified from article reference lists. STUDY SELECTION: Relevant, peer-reviewed original research articles and reviews. RESULTS: Neuromuscular blocking agents, natural rubber latex, antibiotics, and induction agents are the most common causes of anaphylaxis during surgical and interventional procedures. Colloids, opioids, and radiocontrast media probably account for less than 10% of all reactions. Newer agents implicated in anaphylaxis include isosulphan blue and chlorhexidine. Skin tests are useful for evaluating allergic reactions to anesthetic agents and penicillins and for selecting alternative agents. Skin testing and specific IgE measurements for latex vary in allergen standardization and sensitivity and specificity, respectively. Flow cytometric allergen stimulation tests show promise in differentiating allergic from idiosyncratic ("pseudoallergic") reactions. Drug desensitization has been shown to be useful for penicillin anaphylaxis. Premedication with histamine receptor antagonists and corticosteroids helps prevent or attenuate radiocontrast media reactions. CONCLUSIONS: Anaphylaxis during surgical and interventional procedures may be difficult to evaluate because of the rapid, successive use of multiple drugs or diagnostic agents. Careful analysis of anesthetic records and diagnostic tests for all the putative agents are necessary to ensure a complete evaluation.

Anaphylaxis↗

PubMed2003

Drug allergy in a general hospital: Results of a novel prospective inpatient reporting system.

BACKGROUND: Drug allergies are unpredictable immunologic adverse effects, usually immunoglobulin E-mediated immediate hypersensitivity or T-cell-mediated delayed hypersensitivity. There is a paucity of accurate prospective data on drug allergy in hospitalized patients. OBJECTIVE: To describe the incidence, manifestations, and outcome of drug allergy in hospitalized patients. METHODS: All newly developed cases, confirmed or suspected, of drug allergy in inpatients using a network-based electronic notification system. Each notification was evaluated by an allergist-immunologist during the same admission. RESULTS: From December 1, 1997 to December 31, 1999, 366 cases were reported from a total of 90,910 admissions. After review, only 210 cases were verified to have drug allergy. Antimicrobials and anti-epileptic drugs comprised 75% of the drug allergies reported. Cutaneous eruptions were the most common clinical presentation (95.7%), with maculopapular rash being the most common morphology. Systemic manifestations occurred in 30%, of which hepatitis was the most common. Serious adverse reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and generalized exfoliative dermatitis occurred in 11 (5.2%) patients. There was no case of anaphylaxis attributable to drug allergy. After adjusting for underreporting, the incidence of drug allergy in our hospitalized patients was 4.20 per 1,000 (95% confidence interval [CI] 2.93 to 5.46), drug allergy developing during the course of inpatient treatment 2.07 per 1,000 (95% CI 1.45 to 2.69), and mortality attributable to drug allergy 0.09 per 1,000 (95% CI 0.06 to 0.12) hospitalizations. CONCLUSIONS: A network-based, allergist-immunologist-verified, surveillance system enables more accurate labeling of drug allergy. The incidence of drug allergy and mortality in hospitalized patients is low.

Adolescent↗

PubMed2002

A case of Sjögren's syndrome or multiple sclerosis? A diagnostic and therapeutic dilemma.

BACKGROUND: Primary Sjögren's syndrome (SS) with central nervous system involvement and antiphospholipid syndrome have been reported to mimic multiple sclerosis (MS). SS has also been found in patients diagnosed with definite MS. PATIENTS AND METHODS: A Chinese lady developed multiple relapsing neurological events involving the brain and spinal cord from the age of 40 years. Magnetic resonance imaging of the brain and spinal cord during acute relapses showed increased T2 signals and spinal cord edema. She later developed positive anti-nuclear antibody and anti-Ro autoantibody followed by sicca symptoms, confirming the diagnosis of SS. She died from aspiration pneumonia following pseudobulbar palsy shortly after SS was diagnosed. CONCLUSIONS: Patients with MS-like disease and autoantibodies should be carefully evaluated for other systemic autoimmune diseases as the treatment and prognosis differ from MS. In particular, sicca symptoms should be sought as they often go unnoticed by patients. This is especially important in Orientals in whom MS is relatively uncommon.

Adult↗

PubMed2002

Hypersensitivity syndrome associated with dapsone/pyrimethamine (Maloprim) antimalaria chemoprophylaxis.

BACKGROUND: Dapsone 100 mg/pyrimethamine 12.5 mg (Maloprim; Beacons Chemicals Pte Ltd, Singapore) is routinely prescribed for antimalarial chemoprophylaxis in military servicemen in Singapore who are not glucose-6-phosphate dehydrogenase-deficient. METHODS: We report a series of three male National Servicemen with hypersensitivity syndrome from Maloprim. RESULTS: The three patients were diagnosed with hypersensitivity syndrome based on the presence of features of a drug hypersensitivity syndrome including fever, lymphadenopathy, maculopapular exanthema, hepatitis, and definite exposure to weekly Maloprim alone. A mild Coombs positive hemolytic anemia was also observed in one patient. All the clinical, hematologic, and biochemical derangements normalized within 3 months of tapering regimens of moderate-dose prednisolone. CONCLUSIONS: Drug hypersensitivity syndromes can occur even on low-dose, weekly drug regimens. Hypersensitivity syndrome from weekly Maloprim is potentially reversible when recognized and treated early.

Adult↗