Methamphetamine-associated pulseless electrical activity in a young child.

This is a case report of a 19-month-old female who presented to the emergency department in cardiac arrest after methamphetamine exposure. Prior to presentation, she had seizure-like activity and then became unresponsive. On arrival, she had dilated pupils, intermittent clonus, and pulseless electrical activity. She was found to have full thickness circumferential burns of her bilateral lower extremities. She received 12 doses of epinephrine, cardiopulmonary resuscitation, and volume resuscitation after which she had return of spontaneous circulation and was transferred to the intensive care unit on an epinephrine drip. Initial laboratory studies showed a mixed metabolic and respiratory acidosis and hyperglycemia. An initial urine immunoassay for drugs of abuse was negative, however, 5 h later, a second urine immunoassay was positive for amphetamine. The first specimen was also sent for liquid chromatography-mass spectrometry analysis that later returned positive for methamphetamine and amphetamine. In retrospect, the initial urine screen was found to have evidence of amphetamine below the threshold for positivity (500 ng/mL), and the second urine specimen was highly positive, with an amphetamine level of >1450 ng/mL. In this case, what turned out to be a sub-threshold rather than undetectable level was clinically significant, highlighting the challenges of urine screening in cases of suspected poisoning syndromes with atypical presentations. Our case also suggests the possibility of PEA as a presentation of methamphetamine toxicity in a child.

Vecuronium- and Esmolol-Induced Pseudohypernatremia Due to Drug Interference With Ion-Selective Electrodes.

OBJECTIVES: We observed that patients treated with continuous vecuronium or esmolol infusions showed elevated plasma sodium measurements when measured by the routine chemistry analyzer as part of the basic metabolic panel (Vitros 5600; Ortho Clinical Diagnostics, Raritan, NJ), but not by blood gas analyzers (RAPIDLab 1265; Siemens, Tarrytown, NY). Both instruments use direct ion-selective electrode technology, albeit with different sodium ionophores (basic metabolic panel: methyl monensin, blood gas: glass). We questioned if the basic metabolic panel hypernatremia represents artefactual pseudohypernatremia. DESIGN: We added vecuronium bromide or esmolol hydrochloric acid to pooled plasma samples and compared sodium values measured by both methodologies. We queried sodium results from the electronic medical records of patients admitted at Children's Hospital of Philadelphia from 2016 to 2018 and received vecuronium and/or esmolol infusion treatment during their admissions. SETTING: PICU of a quaternary, free-standing children's hospital. PATIENTS: Children admitted to the hospital who received vecuronium and/or esmolol infusion. MEASUREMENTS AND MAIN RESULTS: Sodium was measured in pooled plasma samples by basic metabolic panel and blood gas methodologies after adding vecuronium bromide or esmolol hydrochloric acid, leading to a dose-response increase in basic metabolic panel sodium measurements. A repeated measures regression analysis of our electronic medical records showed that the vecuronium dose predicted the Δ sodium (basic metabolic panel-blood gas) sodium within 12 hours of the vecuronium administration (p < 0.0018). Esmolol showed a similar trend (p = 0.13). This occurred primarily in central line samples with continuous vecuronium or esmolol infusions. CONCLUSIONS: Vecuronium and esmolol can falsely elevate direct ion-selective electrode sodium measurements on Vitros chemistry analyzers. Unexpectedly high sodium measurements in patients receiving vecuronium and/or esmolol infusions should be further investigated with an alternate sample type (i.e., peripheral blood) or measurement methodology (i.e., blood gas) to guide treatment decisions.

The future of laboratory medicine - a 2014 perspective.

Predicting the future is a difficult task. Not surprisingly, there are many examples and assumptions that have proved to be wrong. This review surveys the many predictions, beginning in 1887, about the future of laboratory medicine and its sub-specialties such as clinical chemistry and molecular pathology. It provides a commentary on the accuracy of the predictions and offers opinions on emerging technologies, economic factors and social developments that may play a role in shaping the future of laboratory medicine.