New in vitro analytical approaches for clinical chemistry measurements in critical care.
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.
Meyerhoff
M E
ME
Department of Chemistry, University of Michigan, Ann Arbor 48109.
D001322:Autoanalysis / Q000295:instrumentation; D001774:Blood Chemical Analysis / Q000295:instrumentation*; D003422:Critical Care / Q000458:organization & administration* / Q000592:standards; D004563:Electrochemistry / Q000295:instrumentation*; D004573:Electrolytes / Q000032:analysis; D006400:Hematocrit / Q000295:instrumentation; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation
D004573:Electrolytes