Accuracy of reagent strips in detecting hypoglycemia in the emergency department.

STUDY OBJECTIVE: Although reagent strips are commonly used, their reliability to estimate blood glucose concentration and guide administration of dextrose solutions in the emergency department environment has not been proved. We determined the accuracy of visually interpreted reagent strips (Chemstrip bG, Boehringer Mannheim Corp, Indianapolis, IN) and their ability to identify hypoglycemic patients in the ED. METHODS: We conducted a prospective, nonrandomized blinded clinical study of the visual estimation of blood glucose values by ED personnel using Chemstrip bG reagent strips during a 4-month period. Simultaneously obtained blood samples sent for laboratory glucose determination served as controls. The study was conducted at a large university hospital ED with an urban patient population. A convenience sample of 215 adult ED patients underwent serum glucose determination with data form completion. No study intervention was tested, although timing of administration of dextrose solutions, if given, was recorded. RESULTS: Hypoglycemia was defined as a glucose concentration less than 60 mg/dL on standard laboratory analysis. Reagent strips identified 28 of 29 of these patients (sensitivity=97%), and 171 of 182 patients without hypoglycemia (specificity=94%, negative predictive value=99%) compared with control samples. The 1 false-negative reagent strip reading of 80 mg/dL was obtained from blood stored in a serum separator tube and had a laboratory glucose value of 39 mg/dL. Eighty-seven percent of the reagent strips were within +/-60 mg/dL of the control value for the laboratory glucose reference range less than 350 mg/dL. CONCLUSION: Visually interpreted Chemstrip bG reagent strips provide an acceptable estimation of blood glucose concentration in the ED and are highly sensitive in detecting hypoglycemia.

Salsalate intoxication and ramifications of utilizing nonspecific analytical methods in estimating quantitative blood concentrations.

In a case involving poisoning with salsalate, a salicylate analogue, the initial blood concentration of the parent drug was underestimated because of the low cross-reactivity of the immunoassay used for the analysis. This resulted in unnecessary additional clinical and laboratory evaluations to find the cause of metabolic acidosis exhibited by the patient. Additional findings led to the conclusion that parent salsalate contributed to patient toxicity. For testing purposes, all salicylate compounds should not necessarily be classified into one salicylic acid category, and there must be detailed communication between the caregiver and the laboratory regarding the specific drug history.

Use of amrinone and glucagon in a case of calcium channel blocker overdose.

Hypotension resulting from calcium channel blocker ingestion often is refractory to standard therapeutic modalities. Amrinone and glucagon have been used separately and in combination with other agents in the treatment of calcium channel blocker overdose. We report the successful use of both amrinone and glucagon in the treatment of a 30-year-old woman who ingested 3.6 g of verapamil and presented with refractory hypotension. The use of the two agents together may provide improved inotropic support with minimal increases in myocardial oxygen consumption. In this case, the combination of amrinone and glucagon was safe and effective in the management of the hemodynamic instability associated with calcium channel blocker overdose.

Cinchonism: two case reports and review of acute quinine toxicity and treatment.

Two cases of acute quinine toxicity are presented, one from self-poisoning and the other from an unidentified source. Both patients presented with acute bilateral blindness. They also experienced the classic symptoms of cinchonism, including nausea, vomiting, and tinnitus. Prolongation of the Q-T interval developed in both patients. Serum quinine levels of 5.3 mg/L and 13 mg/L were measured. Although their visual acuity improved, both patients had some residual deficit at follow-up. A review of the literature, including clinical presentation and emergency medicine diagnosis and management, is also presented.