New in vitro analytical approaches for clinical chemistry measurements in critical care

• Published in: Clinical chemistry (Baltimore, Md.) Vol. 36; no. 8; pp. 1567 - 1572
• Main Author: Meyerhoff, ME
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Washington, DC Am Assoc Clin Chem 01.08.1990; American Association for Clinical Chemistry
• Subjects: Analysis of complex biological substances; Analytical, structural and metabolic biochemistry; Autoanalysis - instrumentation; Biological and medical sciences; Blood and biological fluids; Blood Chemical Analysis - instrumentation; Critical Care - organization & administration; Critical Care - standards; Electrochemistry - instrumentation; Electrolytes - analysis; Fundamental and applied biological sciences. Psychology; Hematocrit - instrumentation; Humans; Monitoring, Physiologic - instrumentation; Ion selective electrode; Human; Blood gas; Biological fluid; Electrolyte; Enzyme; Ionogram; Clinical biology; Glucose; Blood; Quantitative analysis
• ISSN: 0009-9147; 1530-8561
• DOI: 10.1093/clinchem/36.8.1567

The effective management of patients in intensive care units, operating rooms, and emergency rooms requires frequent measurement of a select group of analytes, preferably at or near the patient's bedside. Tests recognized as being essential for such management include blood gases and related variables (pH, pO2, pCO2, HCO3-, hematocrit/hemoglobin, O2 saturation), electrolytes (Na+, K+, Ca2+, Cl-), and in some cases, certain metabolites (glucose, lactate, urea, creatinine). This report describes the measurement principles, practical instrumental designs, analytical performance, and limitations of several newer electrochemical sensor-based approaches useful for in vitro determination of these species in undiluted whole-blood samples. Considerable attention is given to the most recent advances in ion-selective electrode technology as they relate to blood gas and electrolyte determinations. Similar attention is given to modern enzyme-electrode techniques, which are useful for direct measurements of metabolites in whole blood. The challenges of integrating these new analytical methods into convenient, multi-analyte, user-friendly, bedside or stat-lab instruments are also discussed.