• DOI:10.1111/j.1749-6632.1962.tb13623.x
• Corpus ID: 33342483

ELECTRODE SYSTEMS FOR CONTINUOUS MONITORING IN CARDIOVASCULAR SURGERY

@article{Clark1962ELECTRODESF,
  title={ELECTRODE SYSTEMS FOR CONTINUOUS MONITORING IN CARDIOVASCULAR SURGERY},
  author={Leland C. Clark and Champ Lyons},
  journal={Annals of the New York Academy of Sciences},
  year={1962},
  volume={102}
}

• Leland C. Clark, C. Lyons
• Published 1 October 1962
• Medicine
• Annals of the New York Academy of Sciences

Instruments capable of continuously indicating the chemical composition of blood have proved to be useful in controlling heart-lung machines, in regulating operative and postoperative management of patients, and in teaching and research. At first, such instruments were used with sensors mounted directly in the extracorporeal blood circuit that is used for perfusion of open-heart surgery patients.] Later, continuous monitoring of both machine and patients was conducted by means of continuous withdrawal of blood pumped into external cuvettes equipped with appropriate sensors. Improvement in the design and construction of electrode systems and their associated electronic instrumentation, together with the commercial development and availability of stable amplifiers and recorders, has now provided entirely satisfactory systems for the rapid and accurate measurement of blood pH, pCO2, and pOz. Electrodes for measurement of blood p 0 2 and $ 0 2 can also be used for recording these tensions in gases. By mixing blood with certain reagents, these electrodes can be used to record blood gas contents as well as tensions. Intravascular electrodes are being used to time hydrogen appearance, to detect changes in oxygen tension, and to record ascorbate indicator dilution curves. Such electrodes are proving valuable in cardiac catheterization and in evaluation of the effectiveness of corrective endocardiac surgical procedures. Speed of response, ease of use, autoclavability, smallness of size, and the practicability of using multiple electrodes simultaneously is often sufficient advantage to overcome the present lack of quantitative response of these relatively simple electrodes. By withdrawing blood through microcatheters, continuous recording of blood composition for many hours, even days, is possible, using only about 10 cc. of blood per hr. Continued development of electrode systems may extend their usefulness to the measurement of blood ions, sugar, and urea and finally result in instruments with which analyses can be performed with a minimum of reagents and with but little delay. Electrode systems readily lend themseIves to either intermittent, semiautomatic, or continuous analytical processes. Blood oxygen tension. Electrodes available at present, mounted in thermostated cuvettes, have proved very satisfactory for the measurement of p 0 2 in blood samples. Thousands of analyses have been performed with the several units available here. We have evaluated several means of utilizing electrodes to follow blood pO2 under conditions encountered in cardiovascular operating rooms and have found that analysis of individual samples, withdrawn in plastic syringes, is the least troublesome and most